1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Atmel ADC driver for SAMA5D2 devices and compatible.
4  *
5  * Copyright (C) 2015 Atmel,
6  *               2015 Ludovic Desroches <ludovic.desroches@atmel.com>
7  *		 2021 Microchip Technology, Inc. and its subsidiaries
8  *		 2021 Eugen Hristev <eugen.hristev@microchip.com>
9  */
10 
11 #include <linux/bitops.h>
12 #include <linux/cleanup.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/dmaengine.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/module.h>
20 #include <linux/mod_devicetable.h>
21 #include <linux/platform_device.h>
22 #include <linux/property.h>
23 #include <linux/sched.h>
24 #include <linux/units.h>
25 #include <linux/wait.h>
26 #include <linux/iio/iio.h>
27 #include <linux/iio/sysfs.h>
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/trigger.h>
30 #include <linux/iio/trigger_consumer.h>
31 #include <linux/iio/triggered_buffer.h>
32 #include <linux/nvmem-consumer.h>
33 #include <linux/pinctrl/consumer.h>
34 #include <linux/pm_runtime.h>
35 #include <linux/regulator/consumer.h>
36 
37 #include <dt-bindings/iio/adc/at91-sama5d2_adc.h>
38 
39 struct at91_adc_reg_layout {
40 /* Control Register */
41 	u16				CR;
42 /* Software Reset */
43 #define	AT91_SAMA5D2_CR_SWRST		BIT(0)
44 /* Start Conversion */
45 #define	AT91_SAMA5D2_CR_START		BIT(1)
46 /* Touchscreen Calibration */
47 #define	AT91_SAMA5D2_CR_TSCALIB		BIT(2)
48 /* Comparison Restart */
49 #define	AT91_SAMA5D2_CR_CMPRST		BIT(4)
50 
51 /* Mode Register */
52 	u16				MR;
53 /* Trigger Selection */
54 #define	AT91_SAMA5D2_MR_TRGSEL(v)	((v) << 1)
55 /* ADTRG */
56 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG0	0
57 /* TIOA0 */
58 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG1	1
59 /* TIOA1 */
60 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG2	2
61 /* TIOA2 */
62 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG3	3
63 /* PWM event line 0 */
64 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG4	4
65 /* PWM event line 1 */
66 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG5	5
67 /* TIOA3 */
68 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG6	6
69 /* RTCOUT0 */
70 #define	AT91_SAMA5D2_MR_TRGSEL_TRIG7	7
71 /* Sleep Mode */
72 #define	AT91_SAMA5D2_MR_SLEEP		BIT(5)
73 /* Fast Wake Up */
74 #define	AT91_SAMA5D2_MR_FWUP		BIT(6)
75 /* Prescaler Rate Selection */
76 #define	AT91_SAMA5D2_MR_PRESCAL(v)	((v) << AT91_SAMA5D2_MR_PRESCAL_OFFSET)
77 #define	AT91_SAMA5D2_MR_PRESCAL_OFFSET	8
78 #define	AT91_SAMA5D2_MR_PRESCAL_MAX	0xff
79 #define AT91_SAMA5D2_MR_PRESCAL_MASK	GENMASK(15, 8)
80 /* Startup Time */
81 #define	AT91_SAMA5D2_MR_STARTUP(v)	((v) << 16)
82 #define AT91_SAMA5D2_MR_STARTUP_MASK	GENMASK(19, 16)
83 /* Minimum startup time for temperature sensor */
84 #define AT91_SAMA5D2_MR_STARTUP_TS_MIN	(50)
85 /* Analog Change */
86 #define	AT91_SAMA5D2_MR_ANACH		BIT(23)
87 /* Tracking Time */
88 #define	AT91_SAMA5D2_MR_TRACKTIM(v)	((v) << 24)
89 #define	AT91_SAMA5D2_MR_TRACKTIM_TS	6
90 #define	AT91_SAMA5D2_MR_TRACKTIM_MAX	0xf
91 /* Transfer Time */
92 #define	AT91_SAMA5D2_MR_TRANSFER(v)	((v) << 28)
93 #define	AT91_SAMA5D2_MR_TRANSFER_MAX	0x3
94 /* Use Sequence Enable */
95 #define	AT91_SAMA5D2_MR_USEQ		BIT(31)
96 
97 /* Channel Sequence Register 1 */
98 	u16				SEQR1;
99 /* Channel Sequence Register 2 */
100 	u16				SEQR2;
101 /* Channel Enable Register */
102 	u16				CHER;
103 /* Channel Disable Register */
104 	u16				CHDR;
105 /* Channel Status Register */
106 	u16				CHSR;
107 /* Last Converted Data Register */
108 	u16				LCDR;
109 /* Interrupt Enable Register */
110 	u16				IER;
111 /* Interrupt Enable Register - TS X measurement ready */
112 #define AT91_SAMA5D2_IER_XRDY   BIT(20)
113 /* Interrupt Enable Register - TS Y measurement ready */
114 #define AT91_SAMA5D2_IER_YRDY   BIT(21)
115 /* Interrupt Enable Register - TS pressure measurement ready */
116 #define AT91_SAMA5D2_IER_PRDY   BIT(22)
117 /* Interrupt Enable Register - Data ready */
118 #define AT91_SAMA5D2_IER_DRDY   BIT(24)
119 /* Interrupt Enable Register - general overrun error */
120 #define AT91_SAMA5D2_IER_GOVRE BIT(25)
121 /* Interrupt Enable Register - Pen detect */
122 #define AT91_SAMA5D2_IER_PEN    BIT(29)
123 /* Interrupt Enable Register - No pen detect */
124 #define AT91_SAMA5D2_IER_NOPEN  BIT(30)
125 
126 /* Interrupt Disable Register */
127 	u16				IDR;
128 /* Interrupt Mask Register */
129 	u16				IMR;
130 /* Interrupt Status Register */
131 	u16				ISR;
132 /* End of Conversion Interrupt Enable Register */
133 	u16				EOC_IER;
134 /* End of Conversion Interrupt Disable Register */
135 	u16				EOC_IDR;
136 /* End of Conversion Interrupt Mask Register */
137 	u16				EOC_IMR;
138 /* End of Conversion Interrupt Status Register */
139 	u16				EOC_ISR;
140 /* Interrupt Status Register - Pen touching sense status */
141 #define AT91_SAMA5D2_ISR_PENS   BIT(31)
142 /* Last Channel Trigger Mode Register */
143 	u16				LCTMR;
144 /* Last Channel Compare Window Register */
145 	u16				LCCWR;
146 /* Overrun Status Register */
147 	u16				OVER;
148 /* Extended Mode Register */
149 	u16				EMR;
150 /* Extended Mode Register - Oversampling rate */
151 #define AT91_SAMA5D2_EMR_OSR(V, M)		(((V) << 16) & (M))
152 #define AT91_SAMA5D2_EMR_OSR_1SAMPLES		0
153 #define AT91_SAMA5D2_EMR_OSR_4SAMPLES		1
154 #define AT91_SAMA5D2_EMR_OSR_16SAMPLES		2
155 #define AT91_SAMA5D2_EMR_OSR_64SAMPLES		3
156 #define AT91_SAMA5D2_EMR_OSR_256SAMPLES		4
157 
158 /* Extended Mode Register - TRACKX */
159 #define AT91_SAMA5D2_TRACKX_MASK		GENMASK(23, 22)
160 #define AT91_SAMA5D2_TRACKX(x)			(((x) << 22) & \
161 						 AT91_SAMA5D2_TRACKX_MASK)
162 /* TRACKX for temperature sensor. */
163 #define AT91_SAMA5D2_TRACKX_TS			(1)
164 
165 /* Extended Mode Register - Averaging on single trigger event */
166 #define AT91_SAMA5D2_EMR_ASTE(V)		((V) << 20)
167 
168 /* Compare Window Register */
169 	u16				CWR;
170 /* Channel Gain Register */
171 	u16				CGR;
172 /* Channel Offset Register */
173 	u16				COR;
174 /* Channel Offset Register differential offset - constant, not a register */
175 	u16				COR_diff_offset;
176 /* Analog Control Register */
177 	u16				ACR;
178 /* Analog Control Register - Pen detect sensitivity mask */
179 #define AT91_SAMA5D2_ACR_PENDETSENS_MASK        GENMASK(1, 0)
180 /* Analog Control Register - Source last channel */
181 #define AT91_SAMA5D2_ACR_SRCLCH		BIT(16)
182 
183 /* Touchscreen Mode Register */
184 	u16				TSMR;
185 /* Touchscreen Mode Register - No touch mode */
186 #define AT91_SAMA5D2_TSMR_TSMODE_NONE           0
187 /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
188 #define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_NO_PRESS 1
189 /* Touchscreen Mode Register - 4 wire screen, pressure measurement */
190 #define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS    2
191 /* Touchscreen Mode Register - 5 wire screen */
192 #define AT91_SAMA5D2_TSMR_TSMODE_5WIRE          3
193 /* Touchscreen Mode Register - Average samples mask */
194 #define AT91_SAMA5D2_TSMR_TSAV_MASK             GENMASK(5, 4)
195 /* Touchscreen Mode Register - Average samples */
196 #define AT91_SAMA5D2_TSMR_TSAV(x)               ((x) << 4)
197 /* Touchscreen Mode Register - Touch/trigger frequency ratio mask */
198 #define AT91_SAMA5D2_TSMR_TSFREQ_MASK           GENMASK(11, 8)
199 /* Touchscreen Mode Register - Touch/trigger frequency ratio */
200 #define AT91_SAMA5D2_TSMR_TSFREQ(x)             ((x) << 8)
201 /* Touchscreen Mode Register - Pen Debounce Time mask */
202 #define AT91_SAMA5D2_TSMR_PENDBC_MASK           GENMASK(31, 28)
203 /* Touchscreen Mode Register - Pen Debounce Time */
204 #define AT91_SAMA5D2_TSMR_PENDBC(x)            ((x) << 28)
205 /* Touchscreen Mode Register - No DMA for touch measurements */
206 #define AT91_SAMA5D2_TSMR_NOTSDMA               BIT(22)
207 /* Touchscreen Mode Register - Disable pen detection */
208 #define AT91_SAMA5D2_TSMR_PENDET_DIS            (0 << 24)
209 /* Touchscreen Mode Register - Enable pen detection */
210 #define AT91_SAMA5D2_TSMR_PENDET_ENA            BIT(24)
211 
212 /* Touchscreen X Position Register */
213 	u16				XPOSR;
214 /* Touchscreen Y Position Register */
215 	u16				YPOSR;
216 /* Touchscreen Pressure Register */
217 	u16				PRESSR;
218 /* Trigger Register */
219 	u16				TRGR;
220 /* Mask for TRGMOD field of TRGR register */
221 #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
222 /* No trigger, only software trigger can start conversions */
223 #define AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER 0
224 /* Trigger Mode external trigger rising edge */
225 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE 1
226 /* Trigger Mode external trigger falling edge */
227 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL 2
228 /* Trigger Mode external trigger any edge */
229 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY 3
230 /* Trigger Mode internal periodic */
231 #define AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC 5
232 /* Trigger Mode - trigger period mask */
233 #define AT91_SAMA5D2_TRGR_TRGPER_MASK           GENMASK(31, 16)
234 /* Trigger Mode - trigger period */
235 #define AT91_SAMA5D2_TRGR_TRGPER(x)             ((x) << 16)
236 
237 /* Correction Select Register */
238 	u16				COSR;
239 /* Correction Value Register */
240 	u16				CVR;
241 /* Channel Error Correction Register */
242 	u16				CECR;
243 /* Write Protection Mode Register */
244 	u16				WPMR;
245 /* Write Protection Status Register */
246 	u16				WPSR;
247 /* Version Register */
248 	u16				VERSION;
249 /* Temperature Sensor Mode Register */
250 	u16				TEMPMR;
251 /* Temperature Sensor Mode - Temperature sensor on */
252 #define AT91_SAMA5D2_TEMPMR_TEMPON	BIT(0)
253 };
254 
255 static const struct at91_adc_reg_layout sama5d2_layout = {
256 	.CR =			0x00,
257 	.MR =			0x04,
258 	.SEQR1 =		0x08,
259 	.SEQR2 =		0x0c,
260 	.CHER =			0x10,
261 	.CHDR =			0x14,
262 	.CHSR =			0x18,
263 	.LCDR =			0x20,
264 	.IER =			0x24,
265 	.IDR =			0x28,
266 	.IMR =			0x2c,
267 	.ISR =			0x30,
268 	.LCTMR =		0x34,
269 	.LCCWR =		0x38,
270 	.OVER =			0x3c,
271 	.EMR =			0x40,
272 	.CWR =			0x44,
273 	.CGR =			0x48,
274 	.COR =			0x4c,
275 	.COR_diff_offset =	16,
276 	.ACR =			0x94,
277 	.TSMR =			0xb0,
278 	.XPOSR =		0xb4,
279 	.YPOSR =		0xb8,
280 	.PRESSR =		0xbc,
281 	.TRGR =			0xc0,
282 	.COSR =			0xd0,
283 	.CVR =			0xd4,
284 	.CECR =			0xd8,
285 	.WPMR =			0xe4,
286 	.WPSR =			0xe8,
287 	.VERSION =		0xfc,
288 };
289 
290 static const struct at91_adc_reg_layout sama7g5_layout = {
291 	.CR =			0x00,
292 	.MR =			0x04,
293 	.SEQR1 =		0x08,
294 	.SEQR2 =		0x0c,
295 	.CHER =			0x10,
296 	.CHDR =			0x14,
297 	.CHSR =			0x18,
298 	.LCDR =			0x20,
299 	.IER =			0x24,
300 	.IDR =			0x28,
301 	.IMR =			0x2c,
302 	.ISR =			0x30,
303 	.EOC_IER =		0x34,
304 	.EOC_IDR =		0x38,
305 	.EOC_IMR =		0x3c,
306 	.EOC_ISR =		0x40,
307 	.TEMPMR =		0x44,
308 	.OVER =			0x4c,
309 	.EMR =			0x50,
310 	.CWR =			0x54,
311 	.COR =			0x5c,
312 	.COR_diff_offset =	0,
313 	.ACR =			0xe0,
314 	.TRGR =			0x100,
315 	.COSR =			0x104,
316 	.CVR =			0x108,
317 	.CECR =			0x10c,
318 	.WPMR =			0x118,
319 	.WPSR =			0x11c,
320 	.VERSION =		0x130,
321 };
322 
323 #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
324 #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US    200
325 
326 #define AT91_SAMA5D2_XYZ_MASK		GENMASK(11, 0)
327 
328 #define AT91_SAMA5D2_MAX_POS_BITS			12
329 
330 #define AT91_HWFIFO_MAX_SIZE_STR	"128"
331 #define AT91_HWFIFO_MAX_SIZE		128
332 
333 #define AT91_SAMA_CHAN_SINGLE(index, num, addr, rbits)			\
334 	{								\
335 		.type = IIO_VOLTAGE,					\
336 		.channel = num,						\
337 		.address = addr,					\
338 		.scan_index = index,					\
339 		.scan_type = {						\
340 			.sign = 'u',					\
341 			.realbits = rbits,				\
342 			.storagebits = 16,				\
343 		},							\
344 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
345 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
346 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
347 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
348 		.info_mask_shared_by_all_available =			\
349 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
350 		.datasheet_name = "CH"#num,				\
351 		.indexed = 1,						\
352 	}
353 
354 #define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr)			\
355 	AT91_SAMA_CHAN_SINGLE(index, num, addr, 14)
356 
357 #define AT91_SAMA7G5_CHAN_SINGLE(index, num, addr)			\
358 	AT91_SAMA_CHAN_SINGLE(index, num, addr, 16)
359 
360 #define AT91_SAMA_CHAN_DIFF(index, num, num2, addr, rbits)		\
361 	{								\
362 		.type = IIO_VOLTAGE,					\
363 		.differential = 1,					\
364 		.channel = num,						\
365 		.channel2 = num2,					\
366 		.address = addr,					\
367 		.scan_index = index,					\
368 		.scan_type = {						\
369 			.sign = 's',					\
370 			.realbits = rbits,				\
371 			.storagebits = 16,				\
372 		},							\
373 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
374 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
375 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
376 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
377 		.info_mask_shared_by_all_available =			\
378 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
379 		.datasheet_name = "CH"#num"-CH"#num2,			\
380 		.indexed = 1,						\
381 	}
382 
383 #define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr)			\
384 	AT91_SAMA_CHAN_DIFF(index, num, num2, addr, 14)
385 
386 #define AT91_SAMA7G5_CHAN_DIFF(index, num, num2, addr)			\
387 	AT91_SAMA_CHAN_DIFF(index, num, num2, addr, 16)
388 
389 #define AT91_SAMA5D2_CHAN_TOUCH(num, name, mod)				\
390 	{								\
391 		.type = IIO_POSITIONRELATIVE,				\
392 		.modified = 1,						\
393 		.channel = num,						\
394 		.channel2 = mod,					\
395 		.scan_index = num,					\
396 		.scan_type = {						\
397 			.sign = 'u',					\
398 			.realbits = 12,					\
399 			.storagebits = 16,				\
400 		},							\
401 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
402 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
403 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
404 		.info_mask_shared_by_all_available =			\
405 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
406 		.datasheet_name = name,					\
407 	}
408 #define AT91_SAMA5D2_CHAN_PRESSURE(num, name)				\
409 	{								\
410 		.type = IIO_PRESSURE,					\
411 		.channel = num,						\
412 		.scan_index = num,					\
413 		.scan_type = {						\
414 			.sign = 'u',					\
415 			.realbits = 12,					\
416 			.storagebits = 16,				\
417 		},							\
418 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
419 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
420 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
421 		.info_mask_shared_by_all_available =			\
422 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
423 		.datasheet_name = name,					\
424 	}
425 
426 #define AT91_SAMA5D2_CHAN_TEMP(num, name, addr)				\
427 	{								\
428 		.type = IIO_TEMP,					\
429 		.channel = num,						\
430 		.address =  addr,					\
431 		.scan_index = num,					\
432 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),	\
433 		.info_mask_shared_by_all =				\
434 				BIT(IIO_CHAN_INFO_PROCESSED) |		\
435 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
436 		.info_mask_shared_by_all_available =			\
437 				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
438 		.datasheet_name = name,					\
439 	}
440 
441 #define at91_adc_readl(st, reg)						\
442 	readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg)
443 #define at91_adc_read_chan(st, reg)					\
444 	readl_relaxed((st)->base + reg)
445 #define at91_adc_writel(st, reg, val)					\
446 	writel_relaxed(val, (st)->base + (st)->soc_info.platform->layout->reg)
447 
448 /**
449  * struct at91_adc_platform - at91-sama5d2 platform information struct
450  * @layout:		pointer to the reg layout struct
451  * @adc_channels:	pointer to an array of channels for registering in
452  *			the iio subsystem
453  * @nr_channels:	number of physical channels available
454  * @touch_chan_x:	index of the touchscreen X channel
455  * @touch_chan_y:	index of the touchscreen Y channel
456  * @touch_chan_p:	index of the touchscreen P channel
457  * @max_channels:	number of total channels
458  * @max_index:		highest channel index (highest index may be higher
459  *			than the total channel number)
460  * @hw_trig_cnt:	number of possible hardware triggers
461  * @osr_mask:		oversampling ratio bitmask on EMR register
462  * @oversampling_avail:	available oversampling values
463  * @oversampling_avail_no: number of available oversampling values
464  * @chan_realbits:	realbits for registered channels
465  * @temp_chan:		temperature channel index
466  * @temp_sensor:	temperature sensor supported
467  */
468 struct at91_adc_platform {
469 	const struct at91_adc_reg_layout	*layout;
470 	const struct iio_chan_spec		(*adc_channels)[];
471 	unsigned int				nr_channels;
472 	unsigned int				touch_chan_x;
473 	unsigned int				touch_chan_y;
474 	unsigned int				touch_chan_p;
475 	unsigned int				max_channels;
476 	unsigned int				max_index;
477 	unsigned int				hw_trig_cnt;
478 	unsigned int				osr_mask;
479 	unsigned int				oversampling_avail[5];
480 	unsigned int				oversampling_avail_no;
481 	unsigned int				chan_realbits;
482 	unsigned int				temp_chan;
483 	bool					temp_sensor;
484 };
485 
486 /**
487  * struct at91_adc_temp_sensor_clb - at91-sama5d2 temperature sensor
488  * calibration data structure
489  * @p1: P1 calibration temperature
490  * @p4: P4 calibration voltage
491  * @p6: P6 calibration voltage
492  */
493 struct at91_adc_temp_sensor_clb {
494 	u32 p1;
495 	u32 p4;
496 	u32 p6;
497 };
498 
499 /**
500  * enum at91_adc_ts_clb_idx - calibration indexes in NVMEM buffer
501  * @AT91_ADC_TS_CLB_IDX_P1: index for P1
502  * @AT91_ADC_TS_CLB_IDX_P4: index for P4
503  * @AT91_ADC_TS_CLB_IDX_P6: index for P6
504  * @AT91_ADC_TS_CLB_IDX_MAX: max index for temperature calibration packet in OTP
505  */
506 enum at91_adc_ts_clb_idx {
507 	AT91_ADC_TS_CLB_IDX_P1 = 2,
508 	AT91_ADC_TS_CLB_IDX_P4 = 5,
509 	AT91_ADC_TS_CLB_IDX_P6 = 7,
510 	AT91_ADC_TS_CLB_IDX_MAX = 19,
511 };
512 
513 /* Temperature sensor calibration - Vtemp voltage sensitivity to temperature. */
514 #define AT91_ADC_TS_VTEMP_DT		(2080U)
515 
516 /**
517  * struct at91_adc_soc_info - at91-sama5d2 soc information struct
518  * @startup_time:	device startup time
519  * @min_sample_rate:	minimum sample rate in Hz
520  * @max_sample_rate:	maximum sample rate in Hz
521  * @platform:		pointer to the platform structure
522  * @temp_sensor_clb:	temperature sensor calibration data structure
523  */
524 struct at91_adc_soc_info {
525 	unsigned			startup_time;
526 	unsigned			min_sample_rate;
527 	unsigned			max_sample_rate;
528 	const struct at91_adc_platform	*platform;
529 	struct at91_adc_temp_sensor_clb	temp_sensor_clb;
530 };
531 
532 struct at91_adc_trigger {
533 	char				*name;
534 	unsigned int			trgmod_value;
535 	unsigned int			edge_type;
536 	bool				hw_trig;
537 };
538 
539 /**
540  * struct at91_adc_dma - at91-sama5d2 dma information struct
541  * @dma_chan:		the dma channel acquired
542  * @rx_buf:		dma coherent allocated area
543  * @rx_dma_buf:		dma handler for the buffer
544  * @phys_addr:		physical address of the ADC base register
545  * @buf_idx:		index inside the dma buffer where reading was last done
546  * @rx_buf_sz:		size of buffer used by DMA operation
547  * @watermark:		number of conversions to copy before DMA triggers irq
548  * @dma_ts:		hold the start timestamp of dma operation
549  */
550 struct at91_adc_dma {
551 	struct dma_chan			*dma_chan;
552 	u8				*rx_buf;
553 	dma_addr_t			rx_dma_buf;
554 	phys_addr_t			phys_addr;
555 	int				buf_idx;
556 	int				rx_buf_sz;
557 	int				watermark;
558 	s64				dma_ts;
559 };
560 
561 /**
562  * struct at91_adc_touch - at91-sama5d2 touchscreen information struct
563  * @sample_period_val:		the value for periodic trigger interval
564  * @touching:			is the pen touching the screen or not
565  * @x_pos:			temporary placeholder for pressure computation
566  * @channels_bitmask:		bitmask with the touchscreen channels enabled
567  * @workq:			workqueue for buffer data pushing
568  */
569 struct at91_adc_touch {
570 	u16				sample_period_val;
571 	bool				touching;
572 	u16				x_pos;
573 	unsigned long			channels_bitmask;
574 	struct work_struct		workq;
575 };
576 
577 /**
578  * struct at91_adc_temp - at91-sama5d2 temperature information structure
579  * @sample_period_val:	sample period value
580  * @saved_sample_rate:	saved sample rate
581  * @saved_oversampling:	saved oversampling
582  */
583 struct at91_adc_temp {
584 	u16				sample_period_val;
585 	u16				saved_sample_rate;
586 	u16				saved_oversampling;
587 };
588 
589 struct at91_adc_state {
590 	void __iomem			*base;
591 	int				irq;
592 	struct clk			*per_clk;
593 	struct regulator		*reg;
594 	struct regulator		*vref;
595 	int				vref_uv;
596 	unsigned int			current_sample_rate;
597 	struct iio_trigger		*trig;
598 	const struct at91_adc_trigger	*selected_trig;
599 	const struct iio_chan_spec	*chan;
600 	bool				conversion_done;
601 	u32				conversion_value;
602 	unsigned int			oversampling_ratio;
603 	struct at91_adc_soc_info	soc_info;
604 	wait_queue_head_t		wq_data_available;
605 	struct at91_adc_dma		dma_st;
606 	struct at91_adc_touch		touch_st;
607 	struct at91_adc_temp		temp_st;
608 	struct iio_dev			*indio_dev;
609 	struct device			*dev;
610 	/* We assume 32 channels for now, has to be increased if needed. */
611 	IIO_DECLARE_BUFFER_WITH_TS(u16, buffer, 32);
612 	/*
613 	 * lock to prevent concurrent 'single conversion' requests through
614 	 * sysfs.
615 	 */
616 	struct mutex			lock;
617 };
618 
619 static const struct at91_adc_trigger at91_adc_trigger_list[] = {
620 	{
621 		.name = "external_rising",
622 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE,
623 		.edge_type = IRQ_TYPE_EDGE_RISING,
624 		.hw_trig = true,
625 	},
626 	{
627 		.name = "external_falling",
628 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL,
629 		.edge_type = IRQ_TYPE_EDGE_FALLING,
630 		.hw_trig = true,
631 	},
632 	{
633 		.name = "external_any",
634 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY,
635 		.edge_type = IRQ_TYPE_EDGE_BOTH,
636 		.hw_trig = true,
637 	},
638 	{
639 		.name = "software",
640 		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER,
641 		.edge_type = IRQ_TYPE_NONE,
642 		.hw_trig = false,
643 	},
644 };
645 
646 static const struct iio_chan_spec at91_sama5d2_adc_channels[] = {
647 	AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x50),
648 	AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x54),
649 	AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x58),
650 	AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x5c),
651 	AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x60),
652 	AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x64),
653 	AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x68),
654 	AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x6c),
655 	AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x70),
656 	AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x74),
657 	AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x78),
658 	AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c),
659 	/* original ABI has the differential channels with a gap in between */
660 	AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50),
661 	AT91_SAMA5D2_CHAN_DIFF(14, 2, 3, 0x58),
662 	AT91_SAMA5D2_CHAN_DIFF(16, 4, 5, 0x60),
663 	AT91_SAMA5D2_CHAN_DIFF(18, 6, 7, 0x68),
664 	AT91_SAMA5D2_CHAN_DIFF(20, 8, 9, 0x70),
665 	AT91_SAMA5D2_CHAN_DIFF(22, 10, 11, 0x78),
666 	IIO_CHAN_SOFT_TIMESTAMP(23),
667 	AT91_SAMA5D2_CHAN_TOUCH(24, "x", IIO_MOD_X),
668 	AT91_SAMA5D2_CHAN_TOUCH(25, "y", IIO_MOD_Y),
669 	AT91_SAMA5D2_CHAN_PRESSURE(26, "pressure"),
670 };
671 
672 static const struct iio_chan_spec at91_sama7g5_adc_channels[] = {
673 	AT91_SAMA7G5_CHAN_SINGLE(0, 0, 0x60),
674 	AT91_SAMA7G5_CHAN_SINGLE(1, 1, 0x64),
675 	AT91_SAMA7G5_CHAN_SINGLE(2, 2, 0x68),
676 	AT91_SAMA7G5_CHAN_SINGLE(3, 3, 0x6c),
677 	AT91_SAMA7G5_CHAN_SINGLE(4, 4, 0x70),
678 	AT91_SAMA7G5_CHAN_SINGLE(5, 5, 0x74),
679 	AT91_SAMA7G5_CHAN_SINGLE(6, 6, 0x78),
680 	AT91_SAMA7G5_CHAN_SINGLE(7, 7, 0x7c),
681 	AT91_SAMA7G5_CHAN_SINGLE(8, 8, 0x80),
682 	AT91_SAMA7G5_CHAN_SINGLE(9, 9, 0x84),
683 	AT91_SAMA7G5_CHAN_SINGLE(10, 10, 0x88),
684 	AT91_SAMA7G5_CHAN_SINGLE(11, 11, 0x8c),
685 	AT91_SAMA7G5_CHAN_SINGLE(12, 12, 0x90),
686 	AT91_SAMA7G5_CHAN_SINGLE(13, 13, 0x94),
687 	AT91_SAMA7G5_CHAN_SINGLE(14, 14, 0x98),
688 	AT91_SAMA7G5_CHAN_SINGLE(15, 15, 0x9c),
689 	AT91_SAMA7G5_CHAN_DIFF(16, 0, 1, 0x60),
690 	AT91_SAMA7G5_CHAN_DIFF(17, 2, 3, 0x68),
691 	AT91_SAMA7G5_CHAN_DIFF(18, 4, 5, 0x70),
692 	AT91_SAMA7G5_CHAN_DIFF(19, 6, 7, 0x78),
693 	AT91_SAMA7G5_CHAN_DIFF(20, 8, 9, 0x80),
694 	AT91_SAMA7G5_CHAN_DIFF(21, 10, 11, 0x88),
695 	AT91_SAMA7G5_CHAN_DIFF(22, 12, 13, 0x90),
696 	AT91_SAMA7G5_CHAN_DIFF(23, 14, 15, 0x98),
697 	IIO_CHAN_SOFT_TIMESTAMP(24),
698 	AT91_SAMA5D2_CHAN_TEMP(AT91_SAMA7G5_ADC_TEMP_CHANNEL, "temp", 0xdc),
699 };
700 
701 static const struct at91_adc_platform sama5d2_platform = {
702 	.layout = &sama5d2_layout,
703 	.adc_channels = &at91_sama5d2_adc_channels,
704 #define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
705 #define AT91_SAMA5D2_DIFF_CHAN_CNT 6
706 	.nr_channels = AT91_SAMA5D2_SINGLE_CHAN_CNT +
707 		       AT91_SAMA5D2_DIFF_CHAN_CNT,
708 #define AT91_SAMA5D2_TOUCH_X_CHAN_IDX	(AT91_SAMA5D2_SINGLE_CHAN_CNT + \
709 					AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
710 	.touch_chan_x = AT91_SAMA5D2_TOUCH_X_CHAN_IDX,
711 #define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX	(AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
712 	.touch_chan_y = AT91_SAMA5D2_TOUCH_Y_CHAN_IDX,
713 #define AT91_SAMA5D2_TOUCH_P_CHAN_IDX	(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
714 	.touch_chan_p = AT91_SAMA5D2_TOUCH_P_CHAN_IDX,
715 #define AT91_SAMA5D2_MAX_CHAN_IDX	AT91_SAMA5D2_TOUCH_P_CHAN_IDX
716 	.max_channels = ARRAY_SIZE(at91_sama5d2_adc_channels),
717 	.max_index = AT91_SAMA5D2_MAX_CHAN_IDX,
718 #define AT91_SAMA5D2_HW_TRIG_CNT	3
719 	.hw_trig_cnt = AT91_SAMA5D2_HW_TRIG_CNT,
720 	.osr_mask = GENMASK(17, 16),
721 	.oversampling_avail = { 1, 4, 16, },
722 	.oversampling_avail_no = 3,
723 	.chan_realbits = 14,
724 };
725 
726 static const struct at91_adc_platform sama7g5_platform = {
727 	.layout = &sama7g5_layout,
728 	.adc_channels = &at91_sama7g5_adc_channels,
729 #define AT91_SAMA7G5_SINGLE_CHAN_CNT	16
730 #define AT91_SAMA7G5_DIFF_CHAN_CNT	8
731 #define AT91_SAMA7G5_TEMP_CHAN_CNT	1
732 	.nr_channels = AT91_SAMA7G5_SINGLE_CHAN_CNT +
733 		       AT91_SAMA7G5_DIFF_CHAN_CNT +
734 		       AT91_SAMA7G5_TEMP_CHAN_CNT,
735 #define AT91_SAMA7G5_MAX_CHAN_IDX	(AT91_SAMA7G5_SINGLE_CHAN_CNT + \
736 					AT91_SAMA7G5_DIFF_CHAN_CNT + \
737 					AT91_SAMA7G5_TEMP_CHAN_CNT)
738 	.max_channels = ARRAY_SIZE(at91_sama7g5_adc_channels),
739 	.max_index = AT91_SAMA7G5_MAX_CHAN_IDX,
740 #define AT91_SAMA7G5_HW_TRIG_CNT	3
741 	.hw_trig_cnt = AT91_SAMA7G5_HW_TRIG_CNT,
742 	.osr_mask = GENMASK(18, 16),
743 	.oversampling_avail = { 1, 4, 16, 64, 256, },
744 	.oversampling_avail_no = 5,
745 	.chan_realbits = 16,
746 	.temp_sensor = true,
747 	.temp_chan = AT91_SAMA7G5_ADC_TEMP_CHANNEL,
748 };
749 
750 static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan)
751 {
752 	int i;
753 
754 	for (i = 0; i < indio_dev->num_channels; i++) {
755 		if (indio_dev->channels[i].scan_index == chan)
756 			return i;
757 	}
758 	return -EINVAL;
759 }
760 
761 static inline struct iio_chan_spec const *
762 at91_adc_chan_get(struct iio_dev *indio_dev, int chan)
763 {
764 	int index = at91_adc_chan_xlate(indio_dev, chan);
765 
766 	if (index < 0)
767 		return NULL;
768 	return indio_dev->channels + index;
769 }
770 
771 static inline int at91_adc_fwnode_xlate(struct iio_dev *indio_dev,
772 					const struct fwnode_reference_args *iiospec)
773 {
774 	return at91_adc_chan_xlate(indio_dev, iiospec->args[0]);
775 }
776 
777 static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev)
778 {
779 	u32 mask = 0;
780 	u8 bit;
781 	struct at91_adc_state *st = iio_priv(indio_dev);
782 
783 	for_each_set_bit(bit, indio_dev->active_scan_mask,
784 			 indio_dev->num_channels) {
785 		struct iio_chan_spec const *chan =
786 			 at91_adc_chan_get(indio_dev, bit);
787 		mask |= BIT(chan->channel);
788 	}
789 
790 	return mask & GENMASK(st->soc_info.platform->nr_channels, 0);
791 }
792 
793 static void at91_adc_cor(struct at91_adc_state *st,
794 			 struct iio_chan_spec const *chan)
795 {
796 	u32 cor, cur_cor;
797 
798 	cor = BIT(chan->channel) | BIT(chan->channel2);
799 
800 	cur_cor = at91_adc_readl(st, COR);
801 	cor <<= st->soc_info.platform->layout->COR_diff_offset;
802 	if (chan->differential)
803 		at91_adc_writel(st, COR, cur_cor | cor);
804 	else
805 		at91_adc_writel(st, COR, cur_cor & ~cor);
806 }
807 
808 static void at91_adc_irq_status(struct at91_adc_state *st, u32 *status,
809 				u32 *eoc)
810 {
811 	*status = at91_adc_readl(st, ISR);
812 	if (st->soc_info.platform->layout->EOC_ISR)
813 		*eoc = at91_adc_readl(st, EOC_ISR);
814 	else
815 		*eoc = *status;
816 }
817 
818 static void at91_adc_irq_mask(struct at91_adc_state *st, u32 *status, u32 *eoc)
819 {
820 	*status = at91_adc_readl(st, IMR);
821 	if (st->soc_info.platform->layout->EOC_IMR)
822 		*eoc = at91_adc_readl(st, EOC_IMR);
823 	else
824 		*eoc = *status;
825 }
826 
827 static void at91_adc_eoc_dis(struct at91_adc_state *st, unsigned int channel)
828 {
829 	/*
830 	 * On some products having the EOC bits in a separate register,
831 	 * errata recommends not writing this register (EOC_IDR).
832 	 * On products having the EOC bits in the IDR register, it's fine to write it.
833 	 */
834 	if (!st->soc_info.platform->layout->EOC_IDR)
835 		at91_adc_writel(st, IDR, BIT(channel));
836 }
837 
838 static void at91_adc_eoc_ena(struct at91_adc_state *st, unsigned int channel)
839 {
840 	if (!st->soc_info.platform->layout->EOC_IDR)
841 		at91_adc_writel(st, IER, BIT(channel));
842 	else
843 		at91_adc_writel(st, EOC_IER, BIT(channel));
844 }
845 
846 static int at91_adc_config_emr(struct at91_adc_state *st,
847 			       u32 oversampling_ratio, u32 trackx)
848 {
849 	/* configure the extended mode register */
850 	unsigned int emr, osr;
851 	unsigned int osr_mask = st->soc_info.platform->osr_mask;
852 	int i, ret;
853 
854 	/* Check against supported oversampling values. */
855 	for (i = 0; i < st->soc_info.platform->oversampling_avail_no; i++) {
856 		if (oversampling_ratio == st->soc_info.platform->oversampling_avail[i])
857 			break;
858 	}
859 	if (i == st->soc_info.platform->oversampling_avail_no)
860 		return -EINVAL;
861 
862 	/* select oversampling ratio from configuration */
863 	switch (oversampling_ratio) {
864 	case 1:
865 		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_1SAMPLES,
866 					   osr_mask);
867 		break;
868 	case 4:
869 		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_4SAMPLES,
870 					   osr_mask);
871 		break;
872 	case 16:
873 		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES,
874 					   osr_mask);
875 		break;
876 	case 64:
877 		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_64SAMPLES,
878 					   osr_mask);
879 		break;
880 	case 256:
881 		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_256SAMPLES,
882 					   osr_mask);
883 		break;
884 	}
885 
886 	ret = pm_runtime_resume_and_get(st->dev);
887 	if (ret < 0)
888 		return ret;
889 
890 	emr = at91_adc_readl(st, EMR);
891 	/* select oversampling per single trigger event */
892 	emr |= AT91_SAMA5D2_EMR_ASTE(1);
893 	/* delete leftover content if it's the case */
894 	emr &= ~(osr_mask | AT91_SAMA5D2_TRACKX_MASK);
895 	/* Update osr and trackx. */
896 	emr |= osr | AT91_SAMA5D2_TRACKX(trackx);
897 	at91_adc_writel(st, EMR, emr);
898 
899 	pm_runtime_mark_last_busy(st->dev);
900 	pm_runtime_put_autosuspend(st->dev);
901 
902 	st->oversampling_ratio = oversampling_ratio;
903 
904 	return 0;
905 }
906 
907 static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val)
908 {
909 	int nbits, diff;
910 
911 	if (st->oversampling_ratio == 1)
912 		nbits = 12;
913 	else if (st->oversampling_ratio == 4)
914 		nbits = 13;
915 	else if (st->oversampling_ratio == 16)
916 		nbits = 14;
917 	else if (st->oversampling_ratio == 64)
918 		nbits = 15;
919 	else if (st->oversampling_ratio == 256)
920 		nbits = 16;
921 	else
922 		/* Should not happen. */
923 		return -EINVAL;
924 
925 	/*
926 	 * We have nbits of real data and channel is registered as
927 	 * st->soc_info.platform->chan_realbits, so shift left diff bits.
928 	 */
929 	diff = st->soc_info.platform->chan_realbits - nbits;
930 	*val <<= diff;
931 
932 	return IIO_VAL_INT;
933 }
934 
935 static void at91_adc_adjust_val_osr_array(struct at91_adc_state *st, void *buf,
936 					  int len)
937 {
938 	int i = 0, val;
939 	u16 *buf_u16 = (u16 *) buf;
940 
941 	/*
942 	 * We are converting each two bytes (each sample).
943 	 * First convert the byte based array to u16, and convert each sample
944 	 * separately.
945 	 * Each value is two bytes in an array of chars, so to not shift
946 	 * more than we need, save the value separately.
947 	 * len is in bytes, so divide by two to get number of samples.
948 	 */
949 	while (i < len / 2) {
950 		val = buf_u16[i];
951 		at91_adc_adjust_val_osr(st, &val);
952 		buf_u16[i] = val;
953 		i++;
954 	}
955 }
956 
957 static int at91_adc_configure_touch(struct at91_adc_state *st, bool state)
958 {
959 	u32 clk_khz = st->current_sample_rate / 1000;
960 	int i = 0, ret;
961 	u16 pendbc;
962 	u32 tsmr, acr;
963 
964 	if (state) {
965 		ret = pm_runtime_resume_and_get(st->dev);
966 		if (ret < 0)
967 			return ret;
968 	} else {
969 		/* disabling touch IRQs and setting mode to no touch enabled */
970 		at91_adc_writel(st, IDR,
971 				AT91_SAMA5D2_IER_PEN | AT91_SAMA5D2_IER_NOPEN);
972 		at91_adc_writel(st, TSMR, 0);
973 
974 		pm_runtime_mark_last_busy(st->dev);
975 		pm_runtime_put_autosuspend(st->dev);
976 		return 0;
977 	}
978 	/*
979 	 * debounce time is in microseconds, we need it in milliseconds to
980 	 * multiply with kilohertz, so, divide by 1000, but after the multiply.
981 	 * round up to make sure pendbc is at least 1
982 	 */
983 	pendbc = round_up(AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US *
984 			  clk_khz / 1000, 1);
985 
986 	/* get the required exponent */
987 	while (pendbc >> i++)
988 		;
989 
990 	pendbc = i;
991 
992 	tsmr = AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS;
993 
994 	tsmr |= AT91_SAMA5D2_TSMR_TSAV(2) & AT91_SAMA5D2_TSMR_TSAV_MASK;
995 	tsmr |= AT91_SAMA5D2_TSMR_PENDBC(pendbc) &
996 		AT91_SAMA5D2_TSMR_PENDBC_MASK;
997 	tsmr |= AT91_SAMA5D2_TSMR_NOTSDMA;
998 	tsmr |= AT91_SAMA5D2_TSMR_PENDET_ENA;
999 	tsmr |= AT91_SAMA5D2_TSMR_TSFREQ(2) & AT91_SAMA5D2_TSMR_TSFREQ_MASK;
1000 
1001 	at91_adc_writel(st, TSMR, tsmr);
1002 
1003 	acr =  at91_adc_readl(st, ACR);
1004 	acr &= ~AT91_SAMA5D2_ACR_PENDETSENS_MASK;
1005 	acr |= 0x02 & AT91_SAMA5D2_ACR_PENDETSENS_MASK;
1006 	at91_adc_writel(st, ACR, acr);
1007 
1008 	/* Sample Period Time = (TRGPER + 1) / ADCClock */
1009 	st->touch_st.sample_period_val =
1010 				 round_up((AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US *
1011 				 clk_khz / 1000) - 1, 1);
1012 	/* enable pen detect IRQ */
1013 	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
1014 
1015 	return 0;
1016 }
1017 
1018 static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg)
1019 {
1020 	u32 val = 0;
1021 	u32 scale, result, pos;
1022 
1023 	/*
1024 	 * to obtain the actual position we must divide by scale
1025 	 * and multiply with max, where
1026 	 * max = 2^AT91_SAMA5D2_MAX_POS_BITS - 1
1027 	 */
1028 	/* first half of register is the x or y, second half is the scale */
1029 	if (reg == st->soc_info.platform->layout->XPOSR)
1030 		val = at91_adc_readl(st, XPOSR);
1031 	else if (reg == st->soc_info.platform->layout->YPOSR)
1032 		val = at91_adc_readl(st, YPOSR);
1033 
1034 	if (!val)
1035 		dev_dbg(&st->indio_dev->dev, "pos is 0\n");
1036 
1037 	pos = val & AT91_SAMA5D2_XYZ_MASK;
1038 	result = (pos << AT91_SAMA5D2_MAX_POS_BITS) - pos;
1039 	scale = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
1040 	if (scale == 0) {
1041 		dev_err(&st->indio_dev->dev, "scale is 0\n");
1042 		return 0;
1043 	}
1044 	result /= scale;
1045 
1046 	return result;
1047 }
1048 
1049 static u16 at91_adc_touch_x_pos(struct at91_adc_state *st)
1050 {
1051 	st->touch_st.x_pos = at91_adc_touch_pos(st, st->soc_info.platform->layout->XPOSR);
1052 	return st->touch_st.x_pos;
1053 }
1054 
1055 static u16 at91_adc_touch_y_pos(struct at91_adc_state *st)
1056 {
1057 	return at91_adc_touch_pos(st, st->soc_info.platform->layout->YPOSR);
1058 }
1059 
1060 static u16 at91_adc_touch_pressure(struct at91_adc_state *st)
1061 {
1062 	u32 val;
1063 	u32 z1, z2;
1064 	u32 pres;
1065 	u32 rxp = 1;
1066 	u32 factor = 1000;
1067 
1068 	/* calculate the pressure */
1069 	val = at91_adc_readl(st, PRESSR);
1070 	z1 = val & AT91_SAMA5D2_XYZ_MASK;
1071 	z2 = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
1072 
1073 	if (z1 != 0)
1074 		pres = rxp * (st->touch_st.x_pos * factor / 1024) *
1075 			(z2 * factor / z1 - factor) /
1076 			factor;
1077 	else
1078 		pres = 0xFFFF;       /* no pen contact */
1079 
1080 	/*
1081 	 * The pressure from device grows down, minimum is 0xFFFF, maximum 0x0.
1082 	 * We compute it this way, but let's return it in the expected way,
1083 	 * growing from 0 to 0xFFFF.
1084 	 */
1085 	return 0xFFFF - pres;
1086 }
1087 
1088 static int at91_adc_read_position(struct at91_adc_state *st, int chan, u16 *val)
1089 {
1090 	*val = 0;
1091 	if (!st->touch_st.touching)
1092 		return -ENODATA;
1093 	if (chan == st->soc_info.platform->touch_chan_x)
1094 		*val = at91_adc_touch_x_pos(st);
1095 	else if (chan == st->soc_info.platform->touch_chan_y)
1096 		*val = at91_adc_touch_y_pos(st);
1097 	else
1098 		return -ENODATA;
1099 
1100 	return IIO_VAL_INT;
1101 }
1102 
1103 static int at91_adc_read_pressure(struct at91_adc_state *st, int chan, u16 *val)
1104 {
1105 	*val = 0;
1106 	if (!st->touch_st.touching)
1107 		return -ENODATA;
1108 	if (chan == st->soc_info.platform->touch_chan_p)
1109 		*val = at91_adc_touch_pressure(st);
1110 	else
1111 		return -ENODATA;
1112 
1113 	return IIO_VAL_INT;
1114 }
1115 
1116 static void at91_adc_configure_trigger_registers(struct at91_adc_state *st,
1117 						 bool state)
1118 {
1119 	u32 status = at91_adc_readl(st, TRGR);
1120 
1121 	/* clear TRGMOD */
1122 	status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK;
1123 
1124 	if (state)
1125 		status |= st->selected_trig->trgmod_value;
1126 
1127 	/* set/unset hw trigger */
1128 	at91_adc_writel(st, TRGR, status);
1129 }
1130 
1131 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
1132 {
1133 	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
1134 	struct at91_adc_state *st = iio_priv(indio);
1135 	int ret;
1136 
1137 	if (state) {
1138 		ret = pm_runtime_resume_and_get(st->dev);
1139 		if (ret < 0)
1140 			return ret;
1141 	}
1142 
1143 	at91_adc_configure_trigger_registers(st, state);
1144 
1145 	if (!state) {
1146 		pm_runtime_mark_last_busy(st->dev);
1147 		pm_runtime_put_autosuspend(st->dev);
1148 	}
1149 
1150 	return 0;
1151 }
1152 
1153 static void at91_adc_reenable_trigger(struct iio_trigger *trig)
1154 {
1155 	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
1156 	struct at91_adc_state *st = iio_priv(indio);
1157 
1158 	/* if we are using DMA, we must not reenable irq after each trigger */
1159 	if (st->dma_st.dma_chan)
1160 		return;
1161 
1162 	enable_irq(st->irq);
1163 
1164 	/* Needed to ACK the DRDY interruption */
1165 	at91_adc_readl(st, LCDR);
1166 }
1167 
1168 static const struct iio_trigger_ops at91_adc_trigger_ops = {
1169 	.set_trigger_state = &at91_adc_configure_trigger,
1170 	.reenable = &at91_adc_reenable_trigger,
1171 	.validate_device = iio_trigger_validate_own_device,
1172 };
1173 
1174 static int at91_adc_dma_size_done(struct at91_adc_state *st)
1175 {
1176 	struct dma_tx_state state;
1177 	enum dma_status status;
1178 	int i, size;
1179 
1180 	status = dmaengine_tx_status(st->dma_st.dma_chan,
1181 				     st->dma_st.dma_chan->cookie,
1182 				     &state);
1183 	if (status != DMA_IN_PROGRESS)
1184 		return 0;
1185 
1186 	/* Transferred length is size in bytes from end of buffer */
1187 	i = st->dma_st.rx_buf_sz - state.residue;
1188 
1189 	/* Return available bytes */
1190 	if (i >= st->dma_st.buf_idx)
1191 		size = i - st->dma_st.buf_idx;
1192 	else
1193 		size = st->dma_st.rx_buf_sz + i - st->dma_st.buf_idx;
1194 	return size;
1195 }
1196 
1197 static void at91_dma_buffer_done(void *data)
1198 {
1199 	struct iio_dev *indio_dev = data;
1200 
1201 	iio_trigger_poll_nested(indio_dev->trig);
1202 }
1203 
1204 static int at91_adc_dma_start(struct iio_dev *indio_dev)
1205 {
1206 	struct at91_adc_state *st = iio_priv(indio_dev);
1207 	struct dma_async_tx_descriptor *desc;
1208 	dma_cookie_t cookie;
1209 	int ret;
1210 	u8 bit;
1211 
1212 	if (!st->dma_st.dma_chan)
1213 		return 0;
1214 
1215 	/* we start a new DMA, so set buffer index to start */
1216 	st->dma_st.buf_idx = 0;
1217 
1218 	/*
1219 	 * compute buffer size w.r.t. watermark and enabled channels.
1220 	 * scan_bytes is aligned so we need an exact size for DMA
1221 	 */
1222 	st->dma_st.rx_buf_sz = 0;
1223 
1224 	for_each_set_bit(bit, indio_dev->active_scan_mask,
1225 			 indio_dev->num_channels) {
1226 		struct iio_chan_spec const *chan =
1227 					 at91_adc_chan_get(indio_dev, bit);
1228 
1229 		if (!chan)
1230 			continue;
1231 
1232 		st->dma_st.rx_buf_sz += chan->scan_type.storagebits / 8;
1233 	}
1234 	st->dma_st.rx_buf_sz *= st->dma_st.watermark;
1235 
1236 	/* Prepare a DMA cyclic transaction */
1237 	desc = dmaengine_prep_dma_cyclic(st->dma_st.dma_chan,
1238 					 st->dma_st.rx_dma_buf,
1239 					 st->dma_st.rx_buf_sz,
1240 					 st->dma_st.rx_buf_sz / 2,
1241 					 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1242 
1243 	if (!desc) {
1244 		dev_err(&indio_dev->dev, "cannot prepare DMA cyclic\n");
1245 		return -EBUSY;
1246 	}
1247 
1248 	desc->callback = at91_dma_buffer_done;
1249 	desc->callback_param = indio_dev;
1250 
1251 	cookie = dmaengine_submit(desc);
1252 	ret = dma_submit_error(cookie);
1253 	if (ret) {
1254 		dev_err(&indio_dev->dev, "cannot submit DMA cyclic\n");
1255 		dmaengine_terminate_async(st->dma_st.dma_chan);
1256 		return ret;
1257 	}
1258 
1259 	/* enable general overrun error signaling */
1260 	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_GOVRE);
1261 	/* Issue pending DMA requests */
1262 	dma_async_issue_pending(st->dma_st.dma_chan);
1263 
1264 	/* consider current time as DMA start time for timestamps */
1265 	st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
1266 
1267 	dev_dbg(&indio_dev->dev, "DMA cyclic started\n");
1268 
1269 	return 0;
1270 }
1271 
1272 static bool at91_adc_buffer_check_use_irq(struct iio_dev *indio,
1273 					  struct at91_adc_state *st)
1274 {
1275 	/* if using DMA, we do not use our own IRQ (we use DMA-controller) */
1276 	if (st->dma_st.dma_chan)
1277 		return false;
1278 	/* if the trigger is not ours, then it has its own IRQ */
1279 	if (iio_trigger_validate_own_device(indio->trig, indio))
1280 		return false;
1281 	return true;
1282 }
1283 
1284 static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev)
1285 {
1286 	struct at91_adc_state *st = iio_priv(indio_dev);
1287 
1288 	return !!bitmap_subset(indio_dev->active_scan_mask,
1289 			       &st->touch_st.channels_bitmask,
1290 			       st->soc_info.platform->max_index + 1);
1291 }
1292 
1293 static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
1294 {
1295 	int ret;
1296 	u8 bit;
1297 	struct at91_adc_state *st = iio_priv(indio_dev);
1298 
1299 	/* check if we are enabling triggered buffer or the touchscreen */
1300 	if (at91_adc_current_chan_is_touch(indio_dev))
1301 		return at91_adc_configure_touch(st, true);
1302 
1303 	/* if we are not in triggered mode, we cannot enable the buffer. */
1304 	if (!(iio_device_get_current_mode(indio_dev) & INDIO_ALL_TRIGGERED_MODES))
1305 		return -EINVAL;
1306 
1307 	ret = pm_runtime_resume_and_get(st->dev);
1308 	if (ret < 0)
1309 		return ret;
1310 
1311 	/* we continue with the triggered buffer */
1312 	ret = at91_adc_dma_start(indio_dev);
1313 	if (ret) {
1314 		dev_err(&indio_dev->dev, "buffer prepare failed\n");
1315 		goto pm_runtime_put;
1316 	}
1317 
1318 	for_each_set_bit(bit, indio_dev->active_scan_mask,
1319 			 indio_dev->num_channels) {
1320 		struct iio_chan_spec const *chan =
1321 					at91_adc_chan_get(indio_dev, bit);
1322 		if (!chan)
1323 			continue;
1324 		/* these channel types cannot be handled by this trigger */
1325 		if (chan->type == IIO_POSITIONRELATIVE ||
1326 		    chan->type == IIO_PRESSURE ||
1327 		    chan->type == IIO_TEMP)
1328 			continue;
1329 
1330 		at91_adc_cor(st, chan);
1331 
1332 		at91_adc_writel(st, CHER, BIT(chan->channel));
1333 	}
1334 
1335 	if (at91_adc_buffer_check_use_irq(indio_dev, st))
1336 		at91_adc_writel(st, IER, AT91_SAMA5D2_IER_DRDY);
1337 
1338 pm_runtime_put:
1339 	pm_runtime_mark_last_busy(st->dev);
1340 	pm_runtime_put_autosuspend(st->dev);
1341 	return ret;
1342 }
1343 
1344 static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev)
1345 {
1346 	struct at91_adc_state *st = iio_priv(indio_dev);
1347 	int ret;
1348 	u8 bit;
1349 
1350 	/* check if we are disabling triggered buffer or the touchscreen */
1351 	if (at91_adc_current_chan_is_touch(indio_dev))
1352 		return at91_adc_configure_touch(st, false);
1353 
1354 	/* if we are not in triggered mode, nothing to do here */
1355 	if (!(iio_device_get_current_mode(indio_dev) & INDIO_ALL_TRIGGERED_MODES))
1356 		return -EINVAL;
1357 
1358 	ret = pm_runtime_resume_and_get(st->dev);
1359 	if (ret < 0)
1360 		return ret;
1361 
1362 	/*
1363 	 * For each enable channel we must disable it in hardware.
1364 	 * In the case of DMA, we must read the last converted value
1365 	 * to clear EOC status and not get a possible interrupt later.
1366 	 * This value is being read by DMA from LCDR anyway, so it's not lost.
1367 	 */
1368 	for_each_set_bit(bit, indio_dev->active_scan_mask,
1369 			 indio_dev->num_channels) {
1370 		struct iio_chan_spec const *chan =
1371 					at91_adc_chan_get(indio_dev, bit);
1372 
1373 		if (!chan)
1374 			continue;
1375 		/* these channel types are virtual, no need to do anything */
1376 		if (chan->type == IIO_POSITIONRELATIVE ||
1377 		    chan->type == IIO_PRESSURE ||
1378 		    chan->type == IIO_TEMP)
1379 			continue;
1380 
1381 		at91_adc_writel(st, CHDR, BIT(chan->channel));
1382 
1383 		if (st->dma_st.dma_chan)
1384 			at91_adc_read_chan(st, chan->address);
1385 	}
1386 
1387 	if (at91_adc_buffer_check_use_irq(indio_dev, st))
1388 		at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_DRDY);
1389 
1390 	/* read overflow register to clear possible overflow status */
1391 	at91_adc_readl(st, OVER);
1392 
1393 	/* if we are using DMA we must clear registers and end DMA */
1394 	if (st->dma_st.dma_chan)
1395 		dmaengine_terminate_sync(st->dma_st.dma_chan);
1396 
1397 	pm_runtime_mark_last_busy(st->dev);
1398 	pm_runtime_put_autosuspend(st->dev);
1399 
1400 	return 0;
1401 }
1402 
1403 static const struct iio_buffer_setup_ops at91_buffer_setup_ops = {
1404 	.postdisable = &at91_adc_buffer_postdisable,
1405 };
1406 
1407 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *indio,
1408 						     char *trigger_name)
1409 {
1410 	struct iio_trigger *trig;
1411 	int ret;
1412 
1413 	trig = devm_iio_trigger_alloc(&indio->dev, "%s-dev%d-%s", indio->name,
1414 				iio_device_id(indio), trigger_name);
1415 	if (!trig)
1416 		return ERR_PTR(-ENOMEM);
1417 
1418 	trig->dev.parent = indio->dev.parent;
1419 	iio_trigger_set_drvdata(trig, indio);
1420 	trig->ops = &at91_adc_trigger_ops;
1421 
1422 	ret = devm_iio_trigger_register(&indio->dev, trig);
1423 	if (ret)
1424 		return ERR_PTR(ret);
1425 
1426 	return trig;
1427 }
1428 
1429 static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
1430 					   struct iio_poll_func *pf)
1431 {
1432 	struct at91_adc_state *st = iio_priv(indio_dev);
1433 	int i = 0;
1434 	int val;
1435 	u8 bit;
1436 	u32 mask = at91_adc_active_scan_mask_to_reg(indio_dev);
1437 	unsigned int timeout = 50;
1438 	u32 status, imr, eoc = 0, eoc_imr;
1439 
1440 	/*
1441 	 * Check if the conversion is ready. If not, wait a little bit, and
1442 	 * in case of timeout exit with an error.
1443 	 */
1444 	while (((eoc & mask) != mask) && timeout) {
1445 		at91_adc_irq_status(st, &status, &eoc);
1446 		at91_adc_irq_mask(st, &imr, &eoc_imr);
1447 		usleep_range(50, 100);
1448 		timeout--;
1449 	}
1450 
1451 	/* Cannot read data, not ready. Continue without reporting data */
1452 	if (!timeout)
1453 		return;
1454 
1455 	for_each_set_bit(bit, indio_dev->active_scan_mask,
1456 			 indio_dev->num_channels) {
1457 		struct iio_chan_spec const *chan =
1458 					at91_adc_chan_get(indio_dev, bit);
1459 
1460 		if (!chan)
1461 			continue;
1462 		/*
1463 		 * Our external trigger only supports the voltage channels.
1464 		 * In case someone requested a different type of channel
1465 		 * just put zeroes to buffer.
1466 		 * This should not happen because we check the scan mode
1467 		 * and scan mask when we enable the buffer, and we don't allow
1468 		 * the buffer to start with a mixed mask (voltage and something
1469 		 * else).
1470 		 * Thus, emit a warning.
1471 		 */
1472 		if (chan->type == IIO_VOLTAGE) {
1473 			val = at91_adc_read_chan(st, chan->address);
1474 			at91_adc_adjust_val_osr(st, &val);
1475 			st->buffer[i] = val;
1476 		} else {
1477 			st->buffer[i] = 0;
1478 			WARN(true, "This trigger cannot handle this type of channel");
1479 		}
1480 		i++;
1481 	}
1482 	iio_push_to_buffers_with_timestamp(indio_dev, st->buffer,
1483 					   pf->timestamp);
1484 }
1485 
1486 static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev)
1487 {
1488 	struct at91_adc_state *st = iio_priv(indio_dev);
1489 	int transferred_len = at91_adc_dma_size_done(st);
1490 	s64 ns = iio_get_time_ns(indio_dev);
1491 	s64 interval;
1492 	int sample_index = 0, sample_count, sample_size;
1493 
1494 	u32 status = at91_adc_readl(st, ISR);
1495 	/* if we reached this point, we cannot sample faster */
1496 	if (status & AT91_SAMA5D2_IER_GOVRE)
1497 		pr_info_ratelimited("%s: conversion overrun detected\n",
1498 				    indio_dev->name);
1499 
1500 	sample_size = div_s64(st->dma_st.rx_buf_sz, st->dma_st.watermark);
1501 
1502 	sample_count = div_s64(transferred_len, sample_size);
1503 
1504 	/*
1505 	 * interval between samples is total time since last transfer handling
1506 	 * divided by the number of samples (total size divided by sample size)
1507 	 */
1508 	interval = div_s64((ns - st->dma_st.dma_ts), sample_count);
1509 
1510 	while (transferred_len >= sample_size) {
1511 		/*
1512 		 * for all the values in the current sample,
1513 		 * adjust the values inside the buffer for oversampling
1514 		 */
1515 		at91_adc_adjust_val_osr_array(st,
1516 					&st->dma_st.rx_buf[st->dma_st.buf_idx],
1517 					sample_size);
1518 
1519 		iio_push_to_buffers_with_timestamp(indio_dev,
1520 				(st->dma_st.rx_buf + st->dma_st.buf_idx),
1521 				(st->dma_st.dma_ts + interval * sample_index));
1522 		/* adjust remaining length */
1523 		transferred_len -= sample_size;
1524 		/* adjust buffer index */
1525 		st->dma_st.buf_idx += sample_size;
1526 		/* in case of reaching end of buffer, reset index */
1527 		if (st->dma_st.buf_idx >= st->dma_st.rx_buf_sz)
1528 			st->dma_st.buf_idx = 0;
1529 		sample_index++;
1530 	}
1531 	/* adjust saved time for next transfer handling */
1532 	st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
1533 }
1534 
1535 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
1536 {
1537 	struct iio_poll_func *pf = p;
1538 	struct iio_dev *indio_dev = pf->indio_dev;
1539 	struct at91_adc_state *st = iio_priv(indio_dev);
1540 
1541 	/*
1542 	 * If it's not our trigger, start a conversion now, as we are
1543 	 * actually polling the trigger now.
1544 	 */
1545 	if (iio_trigger_validate_own_device(indio_dev->trig, indio_dev))
1546 		at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
1547 
1548 	if (st->dma_st.dma_chan)
1549 		at91_adc_trigger_handler_dma(indio_dev);
1550 	else
1551 		at91_adc_trigger_handler_nodma(indio_dev, pf);
1552 
1553 	iio_trigger_notify_done(indio_dev->trig);
1554 
1555 	return IRQ_HANDLED;
1556 }
1557 
1558 static unsigned at91_adc_startup_time(unsigned startup_time_min,
1559 				      unsigned adc_clk_khz)
1560 {
1561 	static const unsigned int startup_lookup[] = {
1562 		  0,   8,  16,  24,
1563 		 64,  80,  96, 112,
1564 		512, 576, 640, 704,
1565 		768, 832, 896, 960
1566 		};
1567 	unsigned ticks_min, i;
1568 
1569 	/*
1570 	 * Since the adc frequency is checked before, there is no reason
1571 	 * to not meet the startup time constraint.
1572 	 */
1573 
1574 	ticks_min = startup_time_min * adc_clk_khz / 1000;
1575 	for (i = 0; i < ARRAY_SIZE(startup_lookup); i++)
1576 		if (startup_lookup[i] > ticks_min)
1577 			break;
1578 
1579 	return i;
1580 }
1581 
1582 static void at91_adc_setup_samp_freq(struct iio_dev *indio_dev, unsigned freq,
1583 				     unsigned int startup_time,
1584 				     unsigned int tracktim)
1585 {
1586 	struct at91_adc_state *st = iio_priv(indio_dev);
1587 	unsigned f_per, prescal, startup, mr;
1588 	int ret;
1589 
1590 	f_per = clk_get_rate(st->per_clk);
1591 	prescal = (f_per / (2 * freq)) - 1;
1592 
1593 	startup = at91_adc_startup_time(startup_time, freq / 1000);
1594 
1595 	ret = pm_runtime_resume_and_get(st->dev);
1596 	if (ret < 0)
1597 		return;
1598 
1599 	mr = at91_adc_readl(st, MR);
1600 	mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK);
1601 	mr |= AT91_SAMA5D2_MR_STARTUP(startup);
1602 	mr |= AT91_SAMA5D2_MR_PRESCAL(prescal);
1603 	mr |= AT91_SAMA5D2_MR_TRACKTIM(tracktim);
1604 	at91_adc_writel(st, MR, mr);
1605 
1606 	pm_runtime_mark_last_busy(st->dev);
1607 	pm_runtime_put_autosuspend(st->dev);
1608 
1609 	dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u, tracktim=%u\n",
1610 		freq, startup, prescal, tracktim);
1611 	st->current_sample_rate = freq;
1612 }
1613 
1614 static inline unsigned at91_adc_get_sample_freq(struct at91_adc_state *st)
1615 {
1616 	return st->current_sample_rate;
1617 }
1618 
1619 static void at91_adc_touch_data_handler(struct iio_dev *indio_dev)
1620 {
1621 	struct at91_adc_state *st = iio_priv(indio_dev);
1622 	u8 bit;
1623 	u16 val;
1624 	int i = 0;
1625 
1626 	for_each_set_bit(bit, indio_dev->active_scan_mask,
1627 			 st->soc_info.platform->max_index + 1) {
1628 		struct iio_chan_spec const *chan =
1629 					 at91_adc_chan_get(indio_dev, bit);
1630 
1631 		if (chan->type == IIO_POSITIONRELATIVE)
1632 			at91_adc_read_position(st, chan->channel, &val);
1633 		else if (chan->type == IIO_PRESSURE)
1634 			at91_adc_read_pressure(st, chan->channel, &val);
1635 		else
1636 			continue;
1637 		st->buffer[i] = val;
1638 		i++;
1639 	}
1640 	/*
1641 	 * Schedule work to push to buffers.
1642 	 * This is intended to push to the callback buffer that another driver
1643 	 * registered. We are still in a handler from our IRQ. If we push
1644 	 * directly, it means the other driver has it's callback called
1645 	 * from our IRQ context. Which is something we better avoid.
1646 	 * Let's schedule it after our IRQ is completed.
1647 	 */
1648 	schedule_work(&st->touch_st.workq);
1649 }
1650 
1651 static void at91_adc_pen_detect_interrupt(struct at91_adc_state *st)
1652 {
1653 	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_PEN);
1654 	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_NOPEN |
1655 			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1656 			AT91_SAMA5D2_IER_PRDY);
1657 	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC |
1658 			AT91_SAMA5D2_TRGR_TRGPER(st->touch_st.sample_period_val));
1659 	st->touch_st.touching = true;
1660 }
1661 
1662 static void at91_adc_no_pen_detect_interrupt(struct iio_dev *indio_dev)
1663 {
1664 	struct at91_adc_state *st = iio_priv(indio_dev);
1665 
1666 	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER);
1667 	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_NOPEN |
1668 			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1669 			AT91_SAMA5D2_IER_PRDY);
1670 	st->touch_st.touching = false;
1671 
1672 	at91_adc_touch_data_handler(indio_dev);
1673 
1674 	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
1675 }
1676 
1677 static void at91_adc_workq_handler(struct work_struct *workq)
1678 {
1679 	struct at91_adc_touch *touch_st = container_of(workq,
1680 					struct at91_adc_touch, workq);
1681 	struct at91_adc_state *st = container_of(touch_st,
1682 					struct at91_adc_state, touch_st);
1683 	struct iio_dev *indio_dev = st->indio_dev;
1684 
1685 	iio_push_to_buffers(indio_dev, st->buffer);
1686 }
1687 
1688 static irqreturn_t at91_adc_interrupt(int irq, void *private)
1689 {
1690 	struct iio_dev *indio = private;
1691 	struct at91_adc_state *st = iio_priv(indio);
1692 	u32 status, eoc, imr, eoc_imr;
1693 	u32 rdy_mask = AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1694 			AT91_SAMA5D2_IER_PRDY;
1695 
1696 	at91_adc_irq_status(st, &status, &eoc);
1697 	at91_adc_irq_mask(st, &imr, &eoc_imr);
1698 
1699 	if (!(status & imr) && !(eoc & eoc_imr))
1700 		return IRQ_NONE;
1701 	if (status & AT91_SAMA5D2_IER_PEN) {
1702 		/* pen detected IRQ */
1703 		at91_adc_pen_detect_interrupt(st);
1704 	} else if ((status & AT91_SAMA5D2_IER_NOPEN)) {
1705 		/* nopen detected IRQ */
1706 		at91_adc_no_pen_detect_interrupt(indio);
1707 	} else if ((status & AT91_SAMA5D2_ISR_PENS) &&
1708 		   ((status & rdy_mask) == rdy_mask)) {
1709 		/* periodic trigger IRQ - during pen sense */
1710 		at91_adc_touch_data_handler(indio);
1711 	} else if (status & AT91_SAMA5D2_ISR_PENS) {
1712 		/*
1713 		 * touching, but the measurements are not ready yet.
1714 		 * read and ignore.
1715 		 */
1716 		status = at91_adc_readl(st, XPOSR);
1717 		status = at91_adc_readl(st, YPOSR);
1718 		status = at91_adc_readl(st, PRESSR);
1719 	} else if (iio_buffer_enabled(indio) &&
1720 		   (status & AT91_SAMA5D2_IER_DRDY)) {
1721 		/* triggered buffer without DMA */
1722 		disable_irq_nosync(irq);
1723 		iio_trigger_poll(indio->trig);
1724 	} else if (iio_buffer_enabled(indio) && st->dma_st.dma_chan) {
1725 		/* triggered buffer with DMA - should not happen */
1726 		disable_irq_nosync(irq);
1727 		WARN(true, "Unexpected irq occurred\n");
1728 	} else if (!iio_buffer_enabled(indio)) {
1729 		/* software requested conversion */
1730 		st->conversion_value = at91_adc_read_chan(st, st->chan->address);
1731 		st->conversion_done = true;
1732 		wake_up_interruptible(&st->wq_data_available);
1733 	}
1734 	return IRQ_HANDLED;
1735 }
1736 
1737 /* This needs to be called with direct mode claimed and st->lock locked. */
1738 static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
1739 				  struct iio_chan_spec const *chan, int *val)
1740 {
1741 	struct at91_adc_state *st = iio_priv(indio_dev);
1742 	u16 tmp_val;
1743 	int ret;
1744 
1745 	ret = pm_runtime_resume_and_get(st->dev);
1746 	if (ret < 0)
1747 		return ret;
1748 
1749 	/*
1750 	 * Keep in mind that we cannot use software trigger or touchscreen
1751 	 * if external trigger is enabled
1752 	 */
1753 	if (chan->type == IIO_POSITIONRELATIVE) {
1754 		ret = at91_adc_read_position(st, chan->channel,
1755 					     &tmp_val);
1756 		*val = tmp_val;
1757 		if (ret > 0)
1758 			ret = at91_adc_adjust_val_osr(st, val);
1759 
1760 		goto pm_runtime_put;
1761 	}
1762 	if (chan->type == IIO_PRESSURE) {
1763 		ret = at91_adc_read_pressure(st, chan->channel,
1764 					     &tmp_val);
1765 		*val = tmp_val;
1766 		if (ret > 0)
1767 			ret = at91_adc_adjust_val_osr(st, val);
1768 
1769 		goto pm_runtime_put;
1770 	}
1771 
1772 	/* in this case we have a voltage or temperature channel */
1773 
1774 	st->chan = chan;
1775 
1776 	at91_adc_cor(st, chan);
1777 	at91_adc_writel(st, CHER, BIT(chan->channel));
1778 	/*
1779 	 * TEMPMR.TEMPON needs to update after CHER otherwise if none
1780 	 * of the channels are enabled and TEMPMR.TEMPON = 1 will
1781 	 * trigger DRDY interruption while preparing for temperature read.
1782 	 */
1783 	if (chan->type == IIO_TEMP)
1784 		at91_adc_writel(st, TEMPMR, AT91_SAMA5D2_TEMPMR_TEMPON);
1785 	at91_adc_eoc_ena(st, chan->channel);
1786 	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
1787 
1788 	ret = wait_event_interruptible_timeout(st->wq_data_available,
1789 					       st->conversion_done,
1790 					       msecs_to_jiffies(1000));
1791 	if (ret == 0)
1792 		ret = -ETIMEDOUT;
1793 
1794 	if (ret > 0) {
1795 		*val = st->conversion_value;
1796 		ret = at91_adc_adjust_val_osr(st, val);
1797 		if (chan->scan_type.sign == 's')
1798 			*val = sign_extend32(*val,
1799 					     chan->scan_type.realbits - 1);
1800 		st->conversion_done = false;
1801 	}
1802 
1803 	at91_adc_eoc_dis(st, st->chan->channel);
1804 	if (chan->type == IIO_TEMP)
1805 		at91_adc_writel(st, TEMPMR, 0U);
1806 	at91_adc_writel(st, CHDR, BIT(chan->channel));
1807 
1808 	/* Needed to ACK the DRDY interruption */
1809 	at91_adc_readl(st, LCDR);
1810 
1811 pm_runtime_put:
1812 	pm_runtime_mark_last_busy(st->dev);
1813 	pm_runtime_put_autosuspend(st->dev);
1814 	return ret;
1815 }
1816 
1817 static int at91_adc_read_info_locked(struct iio_dev *indio_dev,
1818 				     struct iio_chan_spec const *chan, int *val)
1819 {
1820 	struct at91_adc_state *st = iio_priv(indio_dev);
1821 
1822 	guard(mutex)(&st->lock);
1823 
1824 	return at91_adc_read_info_raw(indio_dev, chan, val);
1825 }
1826 
1827 static void at91_adc_temp_sensor_configure(struct at91_adc_state *st,
1828 					   bool start)
1829 {
1830 	u32 sample_rate, oversampling_ratio;
1831 	u32 startup_time, tracktim, trackx;
1832 
1833 	if (start) {
1834 		/*
1835 		 * Configure the sensor for best accuracy: 10MHz frequency,
1836 		 * oversampling rate of 256, tracktim=0xf and trackx=1.
1837 		 */
1838 		sample_rate = 10 * MEGA;
1839 		oversampling_ratio = 256;
1840 		startup_time = AT91_SAMA5D2_MR_STARTUP_TS_MIN;
1841 		tracktim = AT91_SAMA5D2_MR_TRACKTIM_TS;
1842 		trackx = AT91_SAMA5D2_TRACKX_TS;
1843 
1844 		st->temp_st.saved_sample_rate = st->current_sample_rate;
1845 		st->temp_st.saved_oversampling = st->oversampling_ratio;
1846 	} else {
1847 		/* Go back to previous settings. */
1848 		sample_rate = st->temp_st.saved_sample_rate;
1849 		oversampling_ratio = st->temp_st.saved_oversampling;
1850 		startup_time = st->soc_info.startup_time;
1851 		tracktim = 0;
1852 		trackx = 0;
1853 	}
1854 
1855 	at91_adc_setup_samp_freq(st->indio_dev, sample_rate, startup_time,
1856 				 tracktim);
1857 	at91_adc_config_emr(st, oversampling_ratio, trackx);
1858 }
1859 
1860 static int at91_adc_read_temp(struct iio_dev *indio_dev,
1861 			      struct iio_chan_spec const *chan, int *val)
1862 {
1863 	struct at91_adc_state *st = iio_priv(indio_dev);
1864 	struct at91_adc_temp_sensor_clb *clb = &st->soc_info.temp_sensor_clb;
1865 	u64 div1, div2;
1866 	u32 tmp;
1867 	int ret, vbg, vtemp;
1868 
1869 	guard(mutex)(&st->lock);
1870 
1871 	ret = pm_runtime_resume_and_get(st->dev);
1872 	if (ret < 0)
1873 		return ret;
1874 
1875 	at91_adc_temp_sensor_configure(st, true);
1876 
1877 	/* Read VBG. */
1878 	tmp = at91_adc_readl(st, ACR);
1879 	tmp |= AT91_SAMA5D2_ACR_SRCLCH;
1880 	at91_adc_writel(st, ACR, tmp);
1881 	ret = at91_adc_read_info_raw(indio_dev, chan, &vbg);
1882 	if (ret < 0)
1883 		goto restore_config;
1884 
1885 	/* Read VTEMP. */
1886 	tmp &= ~AT91_SAMA5D2_ACR_SRCLCH;
1887 	at91_adc_writel(st, ACR, tmp);
1888 	ret = at91_adc_read_info_raw(indio_dev, chan, &vtemp);
1889 
1890 restore_config:
1891 	/* Revert previous settings. */
1892 	at91_adc_temp_sensor_configure(st, false);
1893 	pm_runtime_mark_last_busy(st->dev);
1894 	pm_runtime_put_autosuspend(st->dev);
1895 	if (ret < 0)
1896 		return ret;
1897 
1898 	/*
1899 	 * Temp[milli] = p1[milli] + (vtemp * clb->p6 - clb->p4 * vbg)/
1900 	 *			     (vbg * AT91_ADC_TS_VTEMP_DT)
1901 	 */
1902 	div1 = DIV_ROUND_CLOSEST_ULL(((u64)vtemp * clb->p6), vbg);
1903 	div1 = DIV_ROUND_CLOSEST_ULL((div1 * 1000), AT91_ADC_TS_VTEMP_DT);
1904 	div2 = DIV_ROUND_CLOSEST_ULL((u64)clb->p4, AT91_ADC_TS_VTEMP_DT);
1905 	div2 *= 1000;
1906 	*val = clb->p1 + (int)div1 - (int)div2;
1907 
1908 	return ret;
1909 }
1910 
1911 static int at91_adc_read_raw(struct iio_dev *indio_dev,
1912 			     struct iio_chan_spec const *chan,
1913 			     int *val, int *val2, long mask)
1914 {
1915 	struct at91_adc_state *st = iio_priv(indio_dev);
1916 	int ret;
1917 
1918 	switch (mask) {
1919 	case IIO_CHAN_INFO_RAW:
1920 		if (!iio_device_claim_direct(indio_dev))
1921 			return -EBUSY;
1922 
1923 		ret = at91_adc_read_info_locked(indio_dev, chan, val);
1924 		iio_device_release_direct(indio_dev);
1925 		return ret;
1926 
1927 	case IIO_CHAN_INFO_SCALE:
1928 		*val = st->vref_uv / 1000;
1929 		if (chan->differential)
1930 			*val *= 2;
1931 		*val2 = chan->scan_type.realbits;
1932 		return IIO_VAL_FRACTIONAL_LOG2;
1933 
1934 	case IIO_CHAN_INFO_PROCESSED:
1935 		if (chan->type != IIO_TEMP)
1936 			return -EINVAL;
1937 		if (!iio_device_claim_direct(indio_dev))
1938 			return -EBUSY;
1939 
1940 		ret = at91_adc_read_temp(indio_dev, chan, val);
1941 		iio_device_release_direct(indio_dev);
1942 
1943 		return ret;
1944 
1945 	case IIO_CHAN_INFO_SAMP_FREQ:
1946 		*val = at91_adc_get_sample_freq(st);
1947 		return IIO_VAL_INT;
1948 
1949 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
1950 		*val = st->oversampling_ratio;
1951 		return IIO_VAL_INT;
1952 
1953 	default:
1954 		return -EINVAL;
1955 	}
1956 }
1957 
1958 static int at91_adc_write_raw(struct iio_dev *indio_dev,
1959 			      struct iio_chan_spec const *chan,
1960 			      int val, int val2, long mask)
1961 {
1962 	struct at91_adc_state *st = iio_priv(indio_dev);
1963 	int ret;
1964 
1965 	switch (mask) {
1966 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
1967 		/* if no change, optimize out */
1968 		if (val == st->oversampling_ratio)
1969 			return 0;
1970 
1971 		if (!iio_device_claim_direct(indio_dev))
1972 			return -EBUSY;
1973 		mutex_lock(&st->lock);
1974 		/* update ratio */
1975 		ret = at91_adc_config_emr(st, val, 0);
1976 		mutex_unlock(&st->lock);
1977 		iio_device_release_direct(indio_dev);
1978 		return ret;
1979 	case IIO_CHAN_INFO_SAMP_FREQ:
1980 		if (val < st->soc_info.min_sample_rate ||
1981 		    val > st->soc_info.max_sample_rate)
1982 			return -EINVAL;
1983 
1984 		if (!iio_device_claim_direct(indio_dev))
1985 			return -EBUSY;
1986 		mutex_lock(&st->lock);
1987 		at91_adc_setup_samp_freq(indio_dev, val,
1988 					 st->soc_info.startup_time, 0);
1989 		mutex_unlock(&st->lock);
1990 		iio_device_release_direct(indio_dev);
1991 		return 0;
1992 	default:
1993 		return -EINVAL;
1994 	}
1995 }
1996 
1997 static int at91_adc_read_avail(struct iio_dev *indio_dev,
1998 			       struct iio_chan_spec const *chan,
1999 			       const int **vals, int *type, int *length,
2000 			       long mask)
2001 {
2002 	struct at91_adc_state *st = iio_priv(indio_dev);
2003 
2004 	switch (mask) {
2005 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
2006 		*vals = (int *)st->soc_info.platform->oversampling_avail;
2007 		*type = IIO_VAL_INT;
2008 		*length = st->soc_info.platform->oversampling_avail_no;
2009 		return IIO_AVAIL_LIST;
2010 	default:
2011 		return -EINVAL;
2012 	}
2013 }
2014 
2015 static void at91_adc_dma_init(struct at91_adc_state *st)
2016 {
2017 	struct device *dev = &st->indio_dev->dev;
2018 	struct dma_slave_config config = {0};
2019 	/* we have 2 bytes for each channel */
2020 	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
2021 	/*
2022 	 * We make the buffer double the size of the fifo,
2023 	 * such that DMA uses one half of the buffer (full fifo size)
2024 	 * and the software uses the other half to read/write.
2025 	 */
2026 	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
2027 					  sample_size * 2, PAGE_SIZE);
2028 
2029 	if (st->dma_st.dma_chan)
2030 		return;
2031 
2032 	st->dma_st.dma_chan = dma_request_chan(dev, "rx");
2033 	if (IS_ERR(st->dma_st.dma_chan))  {
2034 		dev_info(dev, "can't get DMA channel\n");
2035 		st->dma_st.dma_chan = NULL;
2036 		goto dma_exit;
2037 	}
2038 
2039 	st->dma_st.rx_buf = dma_alloc_coherent(st->dma_st.dma_chan->device->dev,
2040 					       pages * PAGE_SIZE,
2041 					       &st->dma_st.rx_dma_buf,
2042 					       GFP_KERNEL);
2043 	if (!st->dma_st.rx_buf) {
2044 		dev_info(dev, "can't allocate coherent DMA area\n");
2045 		goto dma_chan_disable;
2046 	}
2047 
2048 	/* Configure DMA channel to read data register */
2049 	config.direction = DMA_DEV_TO_MEM;
2050 	config.src_addr = (phys_addr_t)(st->dma_st.phys_addr
2051 			  + st->soc_info.platform->layout->LCDR);
2052 	config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
2053 	config.src_maxburst = 1;
2054 	config.dst_maxburst = 1;
2055 
2056 	if (dmaengine_slave_config(st->dma_st.dma_chan, &config)) {
2057 		dev_info(dev, "can't configure DMA slave\n");
2058 		goto dma_free_area;
2059 	}
2060 
2061 	dev_info(dev, "using %s for rx DMA transfers\n",
2062 		 dma_chan_name(st->dma_st.dma_chan));
2063 
2064 	return;
2065 
2066 dma_free_area:
2067 	dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
2068 			  st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
2069 dma_chan_disable:
2070 	dma_release_channel(st->dma_st.dma_chan);
2071 	st->dma_st.dma_chan = NULL;
2072 dma_exit:
2073 	dev_info(dev, "continuing without DMA support\n");
2074 }
2075 
2076 static void at91_adc_dma_disable(struct at91_adc_state *st)
2077 {
2078 	struct device *dev = &st->indio_dev->dev;
2079 	/* we have 2 bytes for each channel */
2080 	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
2081 	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
2082 					  sample_size * 2, PAGE_SIZE);
2083 
2084 	/* if we are not using DMA, just return */
2085 	if (!st->dma_st.dma_chan)
2086 		return;
2087 
2088 	/* wait for all transactions to be terminated first*/
2089 	dmaengine_terminate_sync(st->dma_st.dma_chan);
2090 
2091 	dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
2092 			  st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
2093 	dma_release_channel(st->dma_st.dma_chan);
2094 	st->dma_st.dma_chan = NULL;
2095 
2096 	dev_info(dev, "continuing without DMA support\n");
2097 }
2098 
2099 static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
2100 {
2101 	struct at91_adc_state *st = iio_priv(indio_dev);
2102 	int ret;
2103 
2104 	if (val > AT91_HWFIFO_MAX_SIZE)
2105 		val = AT91_HWFIFO_MAX_SIZE;
2106 
2107 	if (!st->selected_trig->hw_trig) {
2108 		dev_dbg(&indio_dev->dev, "we need hw trigger for DMA\n");
2109 		return 0;
2110 	}
2111 
2112 	dev_dbg(&indio_dev->dev, "new watermark is %u\n", val);
2113 	st->dma_st.watermark = val;
2114 
2115 	/*
2116 	 * The logic here is: if we have watermark 1, it means we do
2117 	 * each conversion with it's own IRQ, thus we don't need DMA.
2118 	 * If the watermark is higher, we do DMA to do all the transfers in bulk
2119 	 */
2120 
2121 	if (val == 1)
2122 		at91_adc_dma_disable(st);
2123 	else if (val > 1)
2124 		at91_adc_dma_init(st);
2125 
2126 	/*
2127 	 * We can start the DMA only after setting the watermark and
2128 	 * having the DMA initialization completed
2129 	 */
2130 	ret = at91_adc_buffer_prepare(indio_dev);
2131 	if (ret)
2132 		at91_adc_dma_disable(st);
2133 
2134 	return ret;
2135 }
2136 
2137 static int at91_adc_update_scan_mode(struct iio_dev *indio_dev,
2138 				     const unsigned long *scan_mask)
2139 {
2140 	struct at91_adc_state *st = iio_priv(indio_dev);
2141 
2142 	if (bitmap_subset(scan_mask, &st->touch_st.channels_bitmask,
2143 			  st->soc_info.platform->max_index + 1))
2144 		return 0;
2145 	/*
2146 	 * if the new bitmap is a combination of touchscreen and regular
2147 	 * channels, then we are not fine
2148 	 */
2149 	if (bitmap_intersects(&st->touch_st.channels_bitmask, scan_mask,
2150 			      st->soc_info.platform->max_index + 1))
2151 		return -EINVAL;
2152 	return 0;
2153 }
2154 
2155 static void at91_adc_hw_init(struct iio_dev *indio_dev)
2156 {
2157 	struct at91_adc_state *st = iio_priv(indio_dev);
2158 
2159 	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
2160 	if (st->soc_info.platform->layout->EOC_IDR)
2161 		at91_adc_writel(st, EOC_IDR, 0xffffffff);
2162 	at91_adc_writel(st, IDR, 0xffffffff);
2163 	/*
2164 	 * Transfer field must be set to 2 according to the datasheet and
2165 	 * allows different analog settings for each channel.
2166 	 */
2167 	at91_adc_writel(st, MR,
2168 			AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH);
2169 
2170 	at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate,
2171 				 st->soc_info.startup_time, 0);
2172 
2173 	/* configure extended mode register */
2174 	at91_adc_config_emr(st, st->oversampling_ratio, 0);
2175 }
2176 
2177 static ssize_t at91_adc_get_fifo_state(struct device *dev,
2178 				       struct device_attribute *attr, char *buf)
2179 {
2180 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
2181 	struct at91_adc_state *st = iio_priv(indio_dev);
2182 
2183 	return sysfs_emit(buf, "%d\n", !!st->dma_st.dma_chan);
2184 }
2185 
2186 static ssize_t at91_adc_get_watermark(struct device *dev,
2187 				      struct device_attribute *attr, char *buf)
2188 {
2189 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
2190 	struct at91_adc_state *st = iio_priv(indio_dev);
2191 
2192 	return sysfs_emit(buf, "%d\n", st->dma_st.watermark);
2193 }
2194 
2195 static IIO_DEVICE_ATTR(hwfifo_enabled, 0444,
2196 		       at91_adc_get_fifo_state, NULL, 0);
2197 static IIO_DEVICE_ATTR(hwfifo_watermark, 0444,
2198 		       at91_adc_get_watermark, NULL, 0);
2199 
2200 IIO_STATIC_CONST_DEVICE_ATTR(hwfifo_watermark_min, "2");
2201 IIO_STATIC_CONST_DEVICE_ATTR(hwfifo_watermark_max, AT91_HWFIFO_MAX_SIZE_STR);
2202 
2203 static const struct iio_dev_attr *at91_adc_fifo_attributes[] = {
2204 	&iio_dev_attr_hwfifo_watermark_min,
2205 	&iio_dev_attr_hwfifo_watermark_max,
2206 	&iio_dev_attr_hwfifo_watermark,
2207 	&iio_dev_attr_hwfifo_enabled,
2208 	NULL,
2209 };
2210 
2211 static const struct iio_info at91_adc_info = {
2212 	.read_avail = &at91_adc_read_avail,
2213 	.read_raw = &at91_adc_read_raw,
2214 	.write_raw = &at91_adc_write_raw,
2215 	.update_scan_mode = &at91_adc_update_scan_mode,
2216 	.fwnode_xlate = &at91_adc_fwnode_xlate,
2217 	.hwfifo_set_watermark = &at91_adc_set_watermark,
2218 };
2219 
2220 static int at91_adc_buffer_and_trigger_init(struct device *dev,
2221 					    struct iio_dev *indio)
2222 {
2223 	struct at91_adc_state *st = iio_priv(indio);
2224 	const struct iio_dev_attr **fifo_attrs;
2225 	int ret;
2226 
2227 	if (st->selected_trig->hw_trig)
2228 		fifo_attrs = at91_adc_fifo_attributes;
2229 	else
2230 		fifo_attrs = NULL;
2231 
2232 	ret = devm_iio_triggered_buffer_setup_ext(&indio->dev, indio,
2233 		&iio_pollfunc_store_time, &at91_adc_trigger_handler,
2234 		IIO_BUFFER_DIRECTION_IN, &at91_buffer_setup_ops, fifo_attrs);
2235 	if (ret < 0) {
2236 		dev_err(dev, "couldn't initialize the buffer.\n");
2237 		return ret;
2238 	}
2239 
2240 	if (!st->selected_trig->hw_trig)
2241 		return 0;
2242 
2243 	st->trig = at91_adc_allocate_trigger(indio, st->selected_trig->name);
2244 	if (IS_ERR(st->trig)) {
2245 		dev_err(dev, "could not allocate trigger\n");
2246 		return PTR_ERR(st->trig);
2247 	}
2248 
2249 	/*
2250 	 * Initially the iio buffer has a length of 2 and
2251 	 * a watermark of 1
2252 	 */
2253 	st->dma_st.watermark = 1;
2254 
2255 	return 0;
2256 }
2257 
2258 static int at91_adc_temp_sensor_init(struct at91_adc_state *st,
2259 				     struct device *dev)
2260 {
2261 	struct at91_adc_temp_sensor_clb *clb = &st->soc_info.temp_sensor_clb;
2262 	struct nvmem_cell *temp_calib;
2263 	u32 *buf;
2264 	size_t len;
2265 	int ret = 0;
2266 
2267 	if (!st->soc_info.platform->temp_sensor)
2268 		return 0;
2269 
2270 	/* Get the calibration data from NVMEM. */
2271 	temp_calib = devm_nvmem_cell_get(dev, "temperature_calib");
2272 	if (IS_ERR(temp_calib)) {
2273 		ret = PTR_ERR(temp_calib);
2274 		if (ret != -ENOENT)
2275 			dev_err(dev, "Failed to get temperature_calib cell!\n");
2276 		return ret;
2277 	}
2278 
2279 	buf = nvmem_cell_read(temp_calib, &len);
2280 	if (IS_ERR(buf)) {
2281 		dev_err(dev, "Failed to read calibration data!\n");
2282 		return PTR_ERR(buf);
2283 	}
2284 	if (len < AT91_ADC_TS_CLB_IDX_MAX * 4) {
2285 		dev_err(dev, "Invalid calibration data!\n");
2286 		ret = -EINVAL;
2287 		goto free_buf;
2288 	}
2289 
2290 	/* Store calibration data for later use. */
2291 	clb->p1 = buf[AT91_ADC_TS_CLB_IDX_P1];
2292 	clb->p4 = buf[AT91_ADC_TS_CLB_IDX_P4];
2293 	clb->p6 = buf[AT91_ADC_TS_CLB_IDX_P6];
2294 
2295 	/*
2296 	 * We prepare here the conversion to milli to avoid doing it on hotpath.
2297 	 */
2298 	clb->p1 = clb->p1 * 1000;
2299 
2300 free_buf:
2301 	kfree(buf);
2302 	return ret;
2303 }
2304 
2305 static int at91_adc_probe(struct platform_device *pdev)
2306 {
2307 	struct device *dev = &pdev->dev;
2308 	struct iio_dev *indio_dev;
2309 	struct at91_adc_state *st;
2310 	struct resource	*res;
2311 	int ret, i, num_channels;
2312 	u32 edge_type = IRQ_TYPE_NONE;
2313 
2314 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
2315 	if (!indio_dev)
2316 		return -ENOMEM;
2317 
2318 	st = iio_priv(indio_dev);
2319 	st->indio_dev = indio_dev;
2320 
2321 	st->soc_info.platform = device_get_match_data(dev);
2322 
2323 	ret = at91_adc_temp_sensor_init(st, &pdev->dev);
2324 	/* Don't register temperature channel if initialization failed. */
2325 	if (ret)
2326 		num_channels = st->soc_info.platform->max_channels - 1;
2327 	else
2328 		num_channels = st->soc_info.platform->max_channels;
2329 
2330 	indio_dev->name = dev_name(&pdev->dev);
2331 	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
2332 	indio_dev->info = &at91_adc_info;
2333 	indio_dev->channels = *st->soc_info.platform->adc_channels;
2334 	indio_dev->num_channels = num_channels;
2335 
2336 	bitmap_set(&st->touch_st.channels_bitmask,
2337 		   st->soc_info.platform->touch_chan_x, 1);
2338 	bitmap_set(&st->touch_st.channels_bitmask,
2339 		   st->soc_info.platform->touch_chan_y, 1);
2340 	bitmap_set(&st->touch_st.channels_bitmask,
2341 		   st->soc_info.platform->touch_chan_p, 1);
2342 
2343 	st->oversampling_ratio = 1;
2344 
2345 	ret = device_property_read_u32(dev, "atmel,min-sample-rate-hz",
2346 				       &st->soc_info.min_sample_rate);
2347 	if (ret) {
2348 		dev_err(&pdev->dev,
2349 			"invalid or missing value for atmel,min-sample-rate-hz\n");
2350 		return ret;
2351 	}
2352 
2353 	ret = device_property_read_u32(dev, "atmel,max-sample-rate-hz",
2354 				       &st->soc_info.max_sample_rate);
2355 	if (ret) {
2356 		dev_err(&pdev->dev,
2357 			"invalid or missing value for atmel,max-sample-rate-hz\n");
2358 		return ret;
2359 	}
2360 
2361 	ret = device_property_read_u32(dev, "atmel,startup-time-ms",
2362 				       &st->soc_info.startup_time);
2363 	if (ret) {
2364 		dev_err(&pdev->dev,
2365 			"invalid or missing value for atmel,startup-time-ms\n");
2366 		return ret;
2367 	}
2368 
2369 	ret = device_property_read_u32(dev, "atmel,trigger-edge-type",
2370 				       &edge_type);
2371 	if (ret) {
2372 		dev_dbg(&pdev->dev,
2373 			"atmel,trigger-edge-type not specified, only software trigger available\n");
2374 	}
2375 
2376 	st->selected_trig = NULL;
2377 
2378 	/* find the right trigger, or no trigger at all */
2379 	for (i = 0; i < st->soc_info.platform->hw_trig_cnt + 1; i++)
2380 		if (at91_adc_trigger_list[i].edge_type == edge_type) {
2381 			st->selected_trig = &at91_adc_trigger_list[i];
2382 			break;
2383 		}
2384 
2385 	if (!st->selected_trig) {
2386 		dev_err(&pdev->dev, "invalid external trigger edge value\n");
2387 		return -EINVAL;
2388 	}
2389 
2390 	init_waitqueue_head(&st->wq_data_available);
2391 	mutex_init(&st->lock);
2392 	INIT_WORK(&st->touch_st.workq, at91_adc_workq_handler);
2393 
2394 	st->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
2395 	if (IS_ERR(st->base))
2396 		return PTR_ERR(st->base);
2397 
2398 	/* if we plan to use DMA, we need the physical address of the regs */
2399 	st->dma_st.phys_addr = res->start;
2400 
2401 	st->irq = platform_get_irq(pdev, 0);
2402 	if (st->irq < 0)
2403 		return st->irq;
2404 
2405 	st->per_clk = devm_clk_get(&pdev->dev, "adc_clk");
2406 	if (IS_ERR(st->per_clk))
2407 		return PTR_ERR(st->per_clk);
2408 
2409 	st->reg = devm_regulator_get(&pdev->dev, "vddana");
2410 	if (IS_ERR(st->reg))
2411 		return PTR_ERR(st->reg);
2412 
2413 	st->vref = devm_regulator_get(&pdev->dev, "vref");
2414 	if (IS_ERR(st->vref))
2415 		return PTR_ERR(st->vref);
2416 
2417 	ret = devm_request_irq(&pdev->dev, st->irq, at91_adc_interrupt, 0,
2418 			       pdev->dev.driver->name, indio_dev);
2419 	if (ret)
2420 		return ret;
2421 
2422 	ret = regulator_enable(st->reg);
2423 	if (ret)
2424 		return ret;
2425 
2426 	ret = regulator_enable(st->vref);
2427 	if (ret)
2428 		goto reg_disable;
2429 
2430 	st->vref_uv = regulator_get_voltage(st->vref);
2431 	if (st->vref_uv <= 0) {
2432 		ret = -EINVAL;
2433 		goto vref_disable;
2434 	}
2435 
2436 	ret = clk_prepare_enable(st->per_clk);
2437 	if (ret)
2438 		goto vref_disable;
2439 
2440 	platform_set_drvdata(pdev, indio_dev);
2441 	st->dev = &pdev->dev;
2442 	pm_runtime_set_autosuspend_delay(st->dev, 500);
2443 	pm_runtime_use_autosuspend(st->dev);
2444 	pm_runtime_set_active(st->dev);
2445 	pm_runtime_enable(st->dev);
2446 	pm_runtime_get_noresume(st->dev);
2447 
2448 	at91_adc_hw_init(indio_dev);
2449 
2450 	ret = at91_adc_buffer_and_trigger_init(&pdev->dev, indio_dev);
2451 	if (ret < 0)
2452 		goto err_pm_disable;
2453 
2454 	if (dma_coerce_mask_and_coherent(&indio_dev->dev, DMA_BIT_MASK(32)))
2455 		dev_info(&pdev->dev, "cannot set DMA mask to 32-bit\n");
2456 
2457 	ret = iio_device_register(indio_dev);
2458 	if (ret < 0)
2459 		goto dma_disable;
2460 
2461 	if (st->selected_trig->hw_trig)
2462 		dev_info(&pdev->dev, "setting up trigger as %s\n",
2463 			 st->selected_trig->name);
2464 
2465 	dev_info(&pdev->dev, "version: %x\n",
2466 		 readl_relaxed(st->base + st->soc_info.platform->layout->VERSION));
2467 
2468 	pm_runtime_mark_last_busy(st->dev);
2469 	pm_runtime_put_autosuspend(st->dev);
2470 
2471 	return 0;
2472 
2473 dma_disable:
2474 	at91_adc_dma_disable(st);
2475 err_pm_disable:
2476 	pm_runtime_put_noidle(st->dev);
2477 	pm_runtime_disable(st->dev);
2478 	pm_runtime_set_suspended(st->dev);
2479 	pm_runtime_dont_use_autosuspend(st->dev);
2480 	clk_disable_unprepare(st->per_clk);
2481 vref_disable:
2482 	regulator_disable(st->vref);
2483 reg_disable:
2484 	regulator_disable(st->reg);
2485 	return ret;
2486 }
2487 
2488 static void at91_adc_remove(struct platform_device *pdev)
2489 {
2490 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
2491 	struct at91_adc_state *st = iio_priv(indio_dev);
2492 
2493 	iio_device_unregister(indio_dev);
2494 
2495 	at91_adc_dma_disable(st);
2496 
2497 	pm_runtime_disable(st->dev);
2498 	pm_runtime_set_suspended(st->dev);
2499 	clk_disable_unprepare(st->per_clk);
2500 
2501 	regulator_disable(st->vref);
2502 	regulator_disable(st->reg);
2503 }
2504 
2505 static int at91_adc_suspend(struct device *dev)
2506 {
2507 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2508 	struct at91_adc_state *st = iio_priv(indio_dev);
2509 	int ret;
2510 
2511 	ret = pm_runtime_resume_and_get(st->dev);
2512 	if (ret < 0)
2513 		return ret;
2514 
2515 	if (iio_buffer_enabled(indio_dev))
2516 		at91_adc_buffer_postdisable(indio_dev);
2517 
2518 	/*
2519 	 * Do a sofware reset of the ADC before we go to suspend.
2520 	 * this will ensure that all pins are free from being muxed by the ADC
2521 	 * and can be used by for other devices.
2522 	 * Otherwise, ADC will hog them and we can't go to suspend mode.
2523 	 */
2524 	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
2525 
2526 	pm_runtime_mark_last_busy(st->dev);
2527 	pm_runtime_put_noidle(st->dev);
2528 	clk_disable_unprepare(st->per_clk);
2529 	regulator_disable(st->vref);
2530 	regulator_disable(st->reg);
2531 
2532 	return pinctrl_pm_select_sleep_state(dev);
2533 }
2534 
2535 static int at91_adc_resume(struct device *dev)
2536 {
2537 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2538 	struct at91_adc_state *st = iio_priv(indio_dev);
2539 	int ret;
2540 
2541 	ret = pinctrl_pm_select_default_state(dev);
2542 	if (ret)
2543 		goto resume_failed;
2544 
2545 	ret = regulator_enable(st->reg);
2546 	if (ret)
2547 		goto resume_failed;
2548 
2549 	ret = regulator_enable(st->vref);
2550 	if (ret)
2551 		goto reg_disable_resume;
2552 
2553 	ret = clk_prepare_enable(st->per_clk);
2554 	if (ret)
2555 		goto vref_disable_resume;
2556 
2557 	pm_runtime_get_noresume(st->dev);
2558 
2559 	at91_adc_hw_init(indio_dev);
2560 
2561 	/* reconfiguring trigger hardware state */
2562 	if (iio_buffer_enabled(indio_dev)) {
2563 		ret = at91_adc_buffer_prepare(indio_dev);
2564 		if (ret)
2565 			goto pm_runtime_put;
2566 
2567 		at91_adc_configure_trigger_registers(st, true);
2568 	}
2569 
2570 	pm_runtime_mark_last_busy(st->dev);
2571 	pm_runtime_put_autosuspend(st->dev);
2572 
2573 	return 0;
2574 
2575 pm_runtime_put:
2576 	pm_runtime_mark_last_busy(st->dev);
2577 	pm_runtime_put_noidle(st->dev);
2578 	clk_disable_unprepare(st->per_clk);
2579 vref_disable_resume:
2580 	regulator_disable(st->vref);
2581 reg_disable_resume:
2582 	regulator_disable(st->reg);
2583 resume_failed:
2584 	dev_err(&indio_dev->dev, "failed to resume\n");
2585 	return ret;
2586 }
2587 
2588 static int at91_adc_runtime_suspend(struct device *dev)
2589 {
2590 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2591 	struct at91_adc_state *st = iio_priv(indio_dev);
2592 
2593 	clk_disable(st->per_clk);
2594 
2595 	return 0;
2596 }
2597 
2598 static int at91_adc_runtime_resume(struct device *dev)
2599 {
2600 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2601 	struct at91_adc_state *st = iio_priv(indio_dev);
2602 
2603 	return clk_enable(st->per_clk);
2604 }
2605 
2606 static const struct dev_pm_ops at91_adc_pm_ops = {
2607 	SYSTEM_SLEEP_PM_OPS(at91_adc_suspend, at91_adc_resume)
2608 	RUNTIME_PM_OPS(at91_adc_runtime_suspend, at91_adc_runtime_resume,
2609 		       NULL)
2610 };
2611 
2612 static const struct of_device_id at91_adc_dt_match[] = {
2613 	{
2614 		.compatible = "atmel,sama5d2-adc",
2615 		.data = (const void *)&sama5d2_platform,
2616 	}, {
2617 		.compatible = "microchip,sama7g5-adc",
2618 		.data = (const void *)&sama7g5_platform,
2619 	}, {
2620 		/* sentinel */
2621 	}
2622 };
2623 MODULE_DEVICE_TABLE(of, at91_adc_dt_match);
2624 
2625 static struct platform_driver at91_adc_driver = {
2626 	.probe = at91_adc_probe,
2627 	.remove = at91_adc_remove,
2628 	.driver = {
2629 		.name = "at91-sama5d2_adc",
2630 		.of_match_table = at91_adc_dt_match,
2631 		.pm = pm_ptr(&at91_adc_pm_ops),
2632 	},
2633 };
2634 module_platform_driver(at91_adc_driver)
2635 
2636 MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@microchip.com>");
2637 MODULE_AUTHOR("Eugen Hristev <eugen.hristev@microchip.com");
2638 MODULE_DESCRIPTION("Atmel AT91 SAMA5D2 ADC");
2639 MODULE_LICENSE("GPL v2");
2640