1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2022 Analog Devices, Inc.
4  * Author: Cosmin Tanislav <cosmin.tanislav@analog.com>
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/bitops.h>
9 #include <linux/cleanup.h>
10 #include <linux/clk.h>
11 #include <linux/clk-provider.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/gpio/driver.h>
16 #include <linux/interrupt.h>
17 #include <linux/irq.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/property.h>
21 #include <linux/regmap.h>
22 #include <linux/regulator/consumer.h>
23 #include <linux/spi/spi.h>
24 #include <linux/units.h>
25 
26 #include <asm/div64.h>
27 #include <linux/unaligned.h>
28 
29 #include <linux/iio/buffer.h>
30 #include <linux/iio/iio.h>
31 #include <linux/iio/kfifo_buf.h>
32 #include <linux/iio/sysfs.h>
33 
34 #define AD4130_NAME				"ad4130"
35 
36 #define AD4130_COMMS_READ_MASK			BIT(6)
37 
38 #define AD4130_STATUS_REG			0x00
39 
40 #define AD4130_ADC_CONTROL_REG			0x01
41 #define AD4130_ADC_CONTROL_BIPOLAR_MASK		BIT(14)
42 #define AD4130_ADC_CONTROL_INT_REF_VAL_MASK	BIT(13)
43 #define AD4130_INT_REF_2_5V			2500000
44 #define AD4130_INT_REF_1_25V			1250000
45 #define AD4130_ADC_CONTROL_CSB_EN_MASK		BIT(9)
46 #define AD4130_ADC_CONTROL_INT_REF_EN_MASK	BIT(8)
47 #define AD4130_ADC_CONTROL_MODE_MASK		GENMASK(5, 2)
48 #define AD4130_ADC_CONTROL_MCLK_SEL_MASK	GENMASK(1, 0)
49 #define AD4130_MCLK_FREQ_76_8KHZ		76800
50 #define AD4130_MCLK_FREQ_153_6KHZ		153600
51 
52 #define AD4130_DATA_REG				0x02
53 
54 #define AD4130_IO_CONTROL_REG			0x03
55 #define AD4130_IO_CONTROL_INT_PIN_SEL_MASK	GENMASK(9, 8)
56 #define AD4130_IO_CONTROL_GPIO_DATA_MASK	GENMASK(7, 4)
57 #define AD4130_IO_CONTROL_GPIO_CTRL_MASK	GENMASK(3, 0)
58 
59 #define AD4130_VBIAS_REG			0x04
60 
61 #define AD4130_ID_REG				0x05
62 
63 #define AD4130_ERROR_REG			0x06
64 
65 #define AD4130_ERROR_EN_REG			0x07
66 
67 #define AD4130_MCLK_COUNT_REG			0x08
68 
69 #define AD4130_CHANNEL_X_REG(x)			(0x09 + (x))
70 #define AD4130_CHANNEL_EN_MASK			BIT(23)
71 #define AD4130_CHANNEL_SETUP_MASK		GENMASK(22, 20)
72 #define AD4130_CHANNEL_AINP_MASK		GENMASK(17, 13)
73 #define AD4130_CHANNEL_AINM_MASK		GENMASK(12, 8)
74 #define AD4130_CHANNEL_IOUT1_MASK		GENMASK(7, 4)
75 #define AD4130_CHANNEL_IOUT2_MASK		GENMASK(3, 0)
76 
77 #define AD4130_CONFIG_X_REG(x)			(0x19 + (x))
78 #define AD4130_CONFIG_IOUT1_VAL_MASK		GENMASK(15, 13)
79 #define AD4130_CONFIG_IOUT2_VAL_MASK		GENMASK(12, 10)
80 #define AD4130_CONFIG_BURNOUT_MASK		GENMASK(9, 8)
81 #define AD4130_CONFIG_REF_BUFP_MASK		BIT(7)
82 #define AD4130_CONFIG_REF_BUFM_MASK		BIT(6)
83 #define AD4130_CONFIG_REF_SEL_MASK		GENMASK(5, 4)
84 #define AD4130_CONFIG_PGA_MASK			GENMASK(3, 1)
85 
86 #define AD4130_FILTER_X_REG(x)			(0x21 + (x))
87 #define AD4130_FILTER_MODE_MASK			GENMASK(15, 12)
88 #define AD4130_FILTER_SELECT_MASK		GENMASK(10, 0)
89 #define AD4130_FILTER_SELECT_MIN		1
90 
91 #define AD4130_OFFSET_X_REG(x)			(0x29 + (x))
92 
93 #define AD4130_GAIN_X_REG(x)			(0x31 + (x))
94 
95 #define AD4130_MISC_REG				0x39
96 
97 #define AD4130_FIFO_CONTROL_REG			0x3a
98 #define AD4130_FIFO_CONTROL_HEADER_MASK		BIT(18)
99 #define AD4130_FIFO_CONTROL_MODE_MASK		GENMASK(17, 16)
100 #define AD4130_FIFO_CONTROL_WM_INT_EN_MASK	BIT(9)
101 #define AD4130_FIFO_CONTROL_WM_MASK		GENMASK(7, 0)
102 #define AD4130_WATERMARK_256			0
103 
104 #define AD4130_FIFO_STATUS_REG			0x3b
105 
106 #define AD4130_FIFO_THRESHOLD_REG		0x3c
107 
108 #define AD4130_FIFO_DATA_REG			0x3d
109 #define AD4130_FIFO_SIZE			256
110 #define AD4130_FIFO_MAX_SAMPLE_SIZE		3
111 
112 #define AD4130_MAX_ANALOG_PINS			16
113 #define AD4130_MAX_CHANNELS			16
114 #define AD4130_MAX_DIFF_INPUTS			30
115 #define AD4130_MAX_GPIOS			4
116 #define AD4130_MAX_ODR				2400
117 #define AD4130_MAX_PGA				8
118 #define AD4130_MAX_SETUPS			8
119 
120 #define AD4130_AIN2_P1				0x2
121 #define AD4130_AIN3_P2				0x3
122 
123 #define AD4130_RESET_BUF_SIZE			8
124 #define AD4130_RESET_SLEEP_US			(160 * MICRO / AD4130_MCLK_FREQ_76_8KHZ)
125 
126 #define AD4130_INVALID_SLOT			-1
127 
128 static const unsigned int ad4130_reg_size[] = {
129 	[AD4130_STATUS_REG] = 1,
130 	[AD4130_ADC_CONTROL_REG] = 2,
131 	[AD4130_DATA_REG] = 3,
132 	[AD4130_IO_CONTROL_REG] = 2,
133 	[AD4130_VBIAS_REG] = 2,
134 	[AD4130_ID_REG] = 1,
135 	[AD4130_ERROR_REG] = 2,
136 	[AD4130_ERROR_EN_REG] = 2,
137 	[AD4130_MCLK_COUNT_REG] = 1,
138 	[AD4130_CHANNEL_X_REG(0) ... AD4130_CHANNEL_X_REG(AD4130_MAX_CHANNELS - 1)] = 3,
139 	[AD4130_CONFIG_X_REG(0) ... AD4130_CONFIG_X_REG(AD4130_MAX_SETUPS - 1)] = 2,
140 	[AD4130_FILTER_X_REG(0) ... AD4130_FILTER_X_REG(AD4130_MAX_SETUPS - 1)] = 3,
141 	[AD4130_OFFSET_X_REG(0) ... AD4130_OFFSET_X_REG(AD4130_MAX_SETUPS - 1)] = 3,
142 	[AD4130_GAIN_X_REG(0) ... AD4130_GAIN_X_REG(AD4130_MAX_SETUPS - 1)] = 3,
143 	[AD4130_MISC_REG] = 2,
144 	[AD4130_FIFO_CONTROL_REG] = 3,
145 	[AD4130_FIFO_STATUS_REG] = 1,
146 	[AD4130_FIFO_THRESHOLD_REG] = 3,
147 	[AD4130_FIFO_DATA_REG] = 3,
148 };
149 
150 enum ad4130_int_ref_val {
151 	AD4130_INT_REF_VAL_2_5V,
152 	AD4130_INT_REF_VAL_1_25V,
153 };
154 
155 enum ad4130_mclk_sel {
156 	AD4130_MCLK_76_8KHZ,
157 	AD4130_MCLK_76_8KHZ_OUT,
158 	AD4130_MCLK_76_8KHZ_EXT,
159 	AD4130_MCLK_153_6KHZ_EXT,
160 };
161 
162 enum ad4130_int_pin_sel {
163 	AD4130_INT_PIN_INT,
164 	AD4130_INT_PIN_CLK,
165 	AD4130_INT_PIN_P2,
166 	AD4130_INT_PIN_DOUT,
167 };
168 
169 enum ad4130_iout {
170 	AD4130_IOUT_OFF,
171 	AD4130_IOUT_10000NA,
172 	AD4130_IOUT_20000NA,
173 	AD4130_IOUT_50000NA,
174 	AD4130_IOUT_100000NA,
175 	AD4130_IOUT_150000NA,
176 	AD4130_IOUT_200000NA,
177 	AD4130_IOUT_100NA,
178 	AD4130_IOUT_MAX
179 };
180 
181 enum ad4130_burnout {
182 	AD4130_BURNOUT_OFF,
183 	AD4130_BURNOUT_500NA,
184 	AD4130_BURNOUT_2000NA,
185 	AD4130_BURNOUT_4000NA,
186 	AD4130_BURNOUT_MAX
187 };
188 
189 enum ad4130_ref_sel {
190 	AD4130_REF_REFIN1,
191 	AD4130_REF_REFIN2,
192 	AD4130_REF_REFOUT_AVSS,
193 	AD4130_REF_AVDD_AVSS,
194 	AD4130_REF_SEL_MAX
195 };
196 
197 enum ad4130_fifo_mode {
198 	AD4130_FIFO_MODE_DISABLED = 0b00,
199 	AD4130_FIFO_MODE_WM = 0b01,
200 };
201 
202 enum ad4130_mode {
203 	AD4130_MODE_CONTINUOUS = 0b0000,
204 	AD4130_MODE_IDLE = 0b0100,
205 };
206 
207 enum ad4130_filter_type {
208 	AD4130_FILTER_SINC4,
209 	AD4130_FILTER_SINC4_SINC1,
210 	AD4130_FILTER_SINC3,
211 	AD4130_FILTER_SINC3_REJ60,
212 	AD4130_FILTER_SINC3_SINC1,
213 	AD4130_FILTER_SINC3_PF1,
214 	AD4130_FILTER_SINC3_PF2,
215 	AD4130_FILTER_SINC3_PF3,
216 	AD4130_FILTER_SINC3_PF4,
217 };
218 
219 enum ad4130_pin_function {
220 	AD4130_PIN_FN_NONE,
221 	AD4130_PIN_FN_SPECIAL = BIT(0),
222 	AD4130_PIN_FN_DIFF = BIT(1),
223 	AD4130_PIN_FN_EXCITATION = BIT(2),
224 	AD4130_PIN_FN_VBIAS = BIT(3),
225 };
226 
227 /*
228  * If you make adaptations in this struct, you most likely also have to adapt
229  * ad4130_setup_info_eq(), too.
230  */
231 struct ad4130_setup_info {
232 	unsigned int			iout0_val;
233 	unsigned int			iout1_val;
234 	unsigned int			burnout;
235 	unsigned int			pga;
236 	unsigned int			fs;
237 	u32				ref_sel;
238 	enum ad4130_filter_type		filter_type;
239 	bool				ref_bufp;
240 	bool				ref_bufm;
241 };
242 
243 struct ad4130_slot_info {
244 	struct ad4130_setup_info	setup;
245 	unsigned int			enabled_channels;
246 	unsigned int			channels;
247 };
248 
249 struct ad4130_chan_info {
250 	struct ad4130_setup_info	setup;
251 	u32				iout0;
252 	u32				iout1;
253 	int				slot;
254 	bool				enabled;
255 	bool				initialized;
256 };
257 
258 struct ad4130_filter_config {
259 	enum ad4130_filter_type		filter_type;
260 	unsigned int			odr_div;
261 	unsigned int			fs_max;
262 	enum iio_available_type		samp_freq_avail_type;
263 	int				samp_freq_avail_len;
264 	int				samp_freq_avail[3][2];
265 };
266 
267 struct ad4130_state {
268 	struct regmap			*regmap;
269 	struct spi_device		*spi;
270 	struct clk			*mclk;
271 	struct regulator_bulk_data	regulators[4];
272 	u32				irq_trigger;
273 	u32				inv_irq_trigger;
274 
275 	/*
276 	 * Synchronize access to members the of driver state, and ensure
277 	 * atomicity of consecutive regmap operations.
278 	 */
279 	struct mutex			lock;
280 	struct completion		completion;
281 
282 	struct iio_chan_spec		chans[AD4130_MAX_CHANNELS];
283 	struct ad4130_chan_info		chans_info[AD4130_MAX_CHANNELS];
284 	struct ad4130_slot_info		slots_info[AD4130_MAX_SETUPS];
285 	enum ad4130_pin_function	pins_fn[AD4130_MAX_ANALOG_PINS];
286 	u32				vbias_pins[AD4130_MAX_ANALOG_PINS];
287 	u32				num_vbias_pins;
288 	int				scale_tbls[AD4130_REF_SEL_MAX][AD4130_MAX_PGA][2];
289 	struct gpio_chip		gc;
290 	struct clk_hw			int_clk_hw;
291 
292 	u32			int_pin_sel;
293 	u32			int_ref_uv;
294 	u32			mclk_sel;
295 	bool			int_ref_en;
296 	bool			bipolar;
297 
298 	unsigned int		num_enabled_channels;
299 	unsigned int		effective_watermark;
300 	unsigned int		watermark;
301 
302 	struct spi_message	fifo_msg;
303 	struct spi_transfer	fifo_xfer[2];
304 
305 	/*
306 	 * DMA (thus cache coherency maintenance) requires any transfer
307 	 * buffers to live in their own cache lines. As the use of these
308 	 * buffers is synchronous, all of the buffers used for DMA in this
309 	 * driver may share a cache line.
310 	 */
311 	u8			reset_buf[AD4130_RESET_BUF_SIZE] __aligned(IIO_DMA_MINALIGN);
312 	u8			reg_write_tx_buf[4];
313 	u8			reg_read_tx_buf[1];
314 	u8			reg_read_rx_buf[3];
315 	u8			fifo_tx_buf[2];
316 	u8			fifo_rx_buf[AD4130_FIFO_SIZE *
317 					    AD4130_FIFO_MAX_SAMPLE_SIZE];
318 };
319 
320 static const char * const ad4130_int_pin_names[] = {
321 	[AD4130_INT_PIN_INT] = "int",
322 	[AD4130_INT_PIN_CLK] = "clk",
323 	[AD4130_INT_PIN_P2] = "p2",
324 	[AD4130_INT_PIN_DOUT] = "dout",
325 };
326 
327 static const unsigned int ad4130_iout_current_na_tbl[AD4130_IOUT_MAX] = {
328 	[AD4130_IOUT_OFF] = 0,
329 	[AD4130_IOUT_100NA] = 100,
330 	[AD4130_IOUT_10000NA] = 10000,
331 	[AD4130_IOUT_20000NA] = 20000,
332 	[AD4130_IOUT_50000NA] = 50000,
333 	[AD4130_IOUT_100000NA] = 100000,
334 	[AD4130_IOUT_150000NA] = 150000,
335 	[AD4130_IOUT_200000NA] = 200000,
336 };
337 
338 static const unsigned int ad4130_burnout_current_na_tbl[AD4130_BURNOUT_MAX] = {
339 	[AD4130_BURNOUT_OFF] = 0,
340 	[AD4130_BURNOUT_500NA] = 500,
341 	[AD4130_BURNOUT_2000NA] = 2000,
342 	[AD4130_BURNOUT_4000NA] = 4000,
343 };
344 
345 #define AD4130_VARIABLE_ODR_CONFIG(_filter_type, _odr_div, _fs_max)	\
346 {									\
347 		.filter_type = (_filter_type),				\
348 		.odr_div = (_odr_div),					\
349 		.fs_max = (_fs_max),					\
350 		.samp_freq_avail_type = IIO_AVAIL_RANGE,		\
351 		.samp_freq_avail = {					\
352 			{ AD4130_MAX_ODR, (_odr_div) * (_fs_max) },	\
353 			{ AD4130_MAX_ODR, (_odr_div) * (_fs_max) },	\
354 			{ AD4130_MAX_ODR, (_odr_div) },			\
355 		},							\
356 }
357 
358 #define AD4130_FIXED_ODR_CONFIG(_filter_type, _odr_div)			\
359 {									\
360 		.filter_type = (_filter_type),				\
361 		.odr_div = (_odr_div),					\
362 		.fs_max = AD4130_FILTER_SELECT_MIN,			\
363 		.samp_freq_avail_type = IIO_AVAIL_LIST,			\
364 		.samp_freq_avail_len = 1,				\
365 		.samp_freq_avail = {					\
366 			{ AD4130_MAX_ODR, (_odr_div) },			\
367 		},							\
368 }
369 
370 static const struct ad4130_filter_config ad4130_filter_configs[] = {
371 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC4,       1,  10),
372 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC4_SINC1, 11, 10),
373 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC3,       1,  2047),
374 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC3_REJ60, 1,  2047),
375 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC3_SINC1, 10, 2047),
376 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF1,      92),
377 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF2,      100),
378 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF3,      124),
379 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF4,      148),
380 };
381 
382 static const char * const ad4130_filter_types_str[] = {
383 	[AD4130_FILTER_SINC4] = "sinc4",
384 	[AD4130_FILTER_SINC4_SINC1] = "sinc4+sinc1",
385 	[AD4130_FILTER_SINC3] = "sinc3",
386 	[AD4130_FILTER_SINC3_REJ60] = "sinc3+rej60",
387 	[AD4130_FILTER_SINC3_SINC1] = "sinc3+sinc1",
388 	[AD4130_FILTER_SINC3_PF1] = "sinc3+pf1",
389 	[AD4130_FILTER_SINC3_PF2] = "sinc3+pf2",
390 	[AD4130_FILTER_SINC3_PF3] = "sinc3+pf3",
391 	[AD4130_FILTER_SINC3_PF4] = "sinc3+pf4",
392 };
393 
394 static int ad4130_get_reg_size(struct ad4130_state *st, unsigned int reg,
395 			       unsigned int *size)
396 {
397 	if (reg >= ARRAY_SIZE(ad4130_reg_size))
398 		return -EINVAL;
399 
400 	*size = ad4130_reg_size[reg];
401 
402 	return 0;
403 }
404 
405 static unsigned int ad4130_data_reg_size(struct ad4130_state *st)
406 {
407 	unsigned int data_reg_size;
408 	int ret;
409 
410 	ret = ad4130_get_reg_size(st, AD4130_DATA_REG, &data_reg_size);
411 	if (ret)
412 		return 0;
413 
414 	return data_reg_size;
415 }
416 
417 static unsigned int ad4130_resolution(struct ad4130_state *st)
418 {
419 	return ad4130_data_reg_size(st) * BITS_PER_BYTE;
420 }
421 
422 static int ad4130_reg_write(void *context, unsigned int reg, unsigned int val)
423 {
424 	struct ad4130_state *st = context;
425 	unsigned int size;
426 	int ret;
427 
428 	ret = ad4130_get_reg_size(st, reg, &size);
429 	if (ret)
430 		return ret;
431 
432 	st->reg_write_tx_buf[0] = reg;
433 
434 	switch (size) {
435 	case 3:
436 		put_unaligned_be24(val, &st->reg_write_tx_buf[1]);
437 		break;
438 	case 2:
439 		put_unaligned_be16(val, &st->reg_write_tx_buf[1]);
440 		break;
441 	case 1:
442 		st->reg_write_tx_buf[1] = val;
443 		break;
444 	default:
445 		return -EINVAL;
446 	}
447 
448 	return spi_write(st->spi, st->reg_write_tx_buf, size + 1);
449 }
450 
451 static int ad4130_reg_read(void *context, unsigned int reg, unsigned int *val)
452 {
453 	struct ad4130_state *st = context;
454 	struct spi_transfer t[] = {
455 		{
456 			.tx_buf = st->reg_read_tx_buf,
457 			.len = sizeof(st->reg_read_tx_buf),
458 		},
459 		{
460 			.rx_buf = st->reg_read_rx_buf,
461 		},
462 	};
463 	unsigned int size;
464 	int ret;
465 
466 	ret = ad4130_get_reg_size(st, reg, &size);
467 	if (ret)
468 		return ret;
469 
470 	st->reg_read_tx_buf[0] = AD4130_COMMS_READ_MASK | reg;
471 	t[1].len = size;
472 
473 	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
474 	if (ret)
475 		return ret;
476 
477 	switch (size) {
478 	case 3:
479 		*val = get_unaligned_be24(st->reg_read_rx_buf);
480 		break;
481 	case 2:
482 		*val = get_unaligned_be16(st->reg_read_rx_buf);
483 		break;
484 	case 1:
485 		*val = st->reg_read_rx_buf[0];
486 		break;
487 	default:
488 		return -EINVAL;
489 	}
490 
491 	return 0;
492 }
493 
494 static const struct regmap_config ad4130_regmap_config = {
495 	.reg_read = ad4130_reg_read,
496 	.reg_write = ad4130_reg_write,
497 };
498 
499 static int ad4130_gpio_init_valid_mask(struct gpio_chip *gc,
500 				       unsigned long *valid_mask,
501 				       unsigned int ngpios)
502 {
503 	struct ad4130_state *st = gpiochip_get_data(gc);
504 	unsigned int i;
505 
506 	/*
507 	 * Output-only GPIO functionality is available on pins AIN2 through
508 	 * AIN5. If these pins are used for anything else, do not expose them.
509 	 */
510 	for (i = 0; i < ngpios; i++) {
511 		unsigned int pin = i + AD4130_AIN2_P1;
512 		bool valid = st->pins_fn[pin] == AD4130_PIN_FN_NONE;
513 
514 		__assign_bit(i, valid_mask, valid);
515 	}
516 
517 	return 0;
518 }
519 
520 static int ad4130_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
521 {
522 	return GPIO_LINE_DIRECTION_OUT;
523 }
524 
525 static int ad4130_gpio_set(struct gpio_chip *gc, unsigned int offset,
526 			   int value)
527 {
528 	struct ad4130_state *st = gpiochip_get_data(gc);
529 	unsigned int mask = FIELD_PREP(AD4130_IO_CONTROL_GPIO_DATA_MASK,
530 				       BIT(offset));
531 
532 	return regmap_update_bits(st->regmap, AD4130_IO_CONTROL_REG, mask,
533 				  value ? mask : 0);
534 }
535 
536 static int ad4130_set_mode(struct ad4130_state *st, enum ad4130_mode mode)
537 {
538 	return regmap_update_bits(st->regmap, AD4130_ADC_CONTROL_REG,
539 				  AD4130_ADC_CONTROL_MODE_MASK,
540 				  FIELD_PREP(AD4130_ADC_CONTROL_MODE_MASK, mode));
541 }
542 
543 static int ad4130_set_watermark_interrupt_en(struct ad4130_state *st, bool en)
544 {
545 	return regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
546 				  AD4130_FIFO_CONTROL_WM_INT_EN_MASK,
547 				  FIELD_PREP(AD4130_FIFO_CONTROL_WM_INT_EN_MASK, en));
548 }
549 
550 static unsigned int ad4130_watermark_reg_val(unsigned int val)
551 {
552 	if (val == AD4130_FIFO_SIZE)
553 		val = AD4130_WATERMARK_256;
554 
555 	return val;
556 }
557 
558 static int ad4130_set_fifo_mode(struct ad4130_state *st,
559 				enum ad4130_fifo_mode mode)
560 {
561 	return regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
562 				  AD4130_FIFO_CONTROL_MODE_MASK,
563 				  FIELD_PREP(AD4130_FIFO_CONTROL_MODE_MASK, mode));
564 }
565 
566 static void ad4130_push_fifo_data(struct iio_dev *indio_dev)
567 {
568 	struct ad4130_state *st = iio_priv(indio_dev);
569 	unsigned int data_reg_size = ad4130_data_reg_size(st);
570 	unsigned int transfer_len = st->effective_watermark * data_reg_size;
571 	unsigned int set_size = st->num_enabled_channels * data_reg_size;
572 	unsigned int i;
573 	int ret;
574 
575 	st->fifo_tx_buf[1] = ad4130_watermark_reg_val(st->effective_watermark);
576 	st->fifo_xfer[1].len = transfer_len;
577 
578 	ret = spi_sync(st->spi, &st->fifo_msg);
579 	if (ret)
580 		return;
581 
582 	for (i = 0; i < transfer_len; i += set_size)
583 		iio_push_to_buffers(indio_dev, &st->fifo_rx_buf[i]);
584 }
585 
586 static irqreturn_t ad4130_irq_handler(int irq, void *private)
587 {
588 	struct iio_dev *indio_dev = private;
589 	struct ad4130_state *st = iio_priv(indio_dev);
590 
591 	if (iio_buffer_enabled(indio_dev))
592 		ad4130_push_fifo_data(indio_dev);
593 	else
594 		complete(&st->completion);
595 
596 	return IRQ_HANDLED;
597 }
598 
599 static bool ad4130_setup_info_eq(struct ad4130_setup_info *a,
600 				 struct ad4130_setup_info *b)
601 {
602 	/*
603 	 * This is just to make sure that the comparison is adapted after
604 	 * struct ad4130_setup_info was changed.
605 	 */
606 	static_assert(sizeof(*a) ==
607 		      sizeof(struct {
608 				     unsigned int iout0_val;
609 				     unsigned int iout1_val;
610 				     unsigned int burnout;
611 				     unsigned int pga;
612 				     unsigned int fs;
613 				     u32 ref_sel;
614 				     enum ad4130_filter_type filter_type;
615 				     bool ref_bufp;
616 				     bool ref_bufm;
617 			     }));
618 
619 	if (a->iout0_val != b->iout0_val ||
620 	    a->iout1_val != b->iout1_val ||
621 	    a->burnout != b->burnout ||
622 	    a->pga != b->pga ||
623 	    a->fs != b->fs ||
624 	    a->ref_sel != b->ref_sel ||
625 	    a->filter_type != b->filter_type ||
626 	    a->ref_bufp != b->ref_bufp ||
627 	    a->ref_bufm != b->ref_bufm)
628 		return false;
629 
630 	return true;
631 }
632 
633 static int ad4130_find_slot(struct ad4130_state *st,
634 			    struct ad4130_setup_info *target_setup_info,
635 			    unsigned int *slot, bool *overwrite)
636 {
637 	unsigned int i;
638 
639 	*slot = AD4130_INVALID_SLOT;
640 	*overwrite = false;
641 
642 	for (i = 0; i < AD4130_MAX_SETUPS; i++) {
643 		struct ad4130_slot_info *slot_info = &st->slots_info[i];
644 
645 		/* Immediately accept a matching setup info. */
646 		if (ad4130_setup_info_eq(target_setup_info, &slot_info->setup)) {
647 			*slot = i;
648 			return 0;
649 		}
650 
651 		/* Ignore all setups which are used by enabled channels. */
652 		if (slot_info->enabled_channels)
653 			continue;
654 
655 		/* Find the least used slot. */
656 		if (*slot == AD4130_INVALID_SLOT ||
657 		    slot_info->channels < st->slots_info[*slot].channels)
658 			*slot = i;
659 	}
660 
661 	if (*slot == AD4130_INVALID_SLOT)
662 		return -EINVAL;
663 
664 	*overwrite = true;
665 
666 	return 0;
667 }
668 
669 static void ad4130_unlink_channel(struct ad4130_state *st, unsigned int channel)
670 {
671 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
672 	struct ad4130_slot_info *slot_info = &st->slots_info[chan_info->slot];
673 
674 	chan_info->slot = AD4130_INVALID_SLOT;
675 	slot_info->channels--;
676 }
677 
678 static int ad4130_unlink_slot(struct ad4130_state *st, unsigned int slot)
679 {
680 	unsigned int i;
681 
682 	for (i = 0; i < AD4130_MAX_CHANNELS; i++) {
683 		struct ad4130_chan_info *chan_info = &st->chans_info[i];
684 
685 		if (!chan_info->initialized || chan_info->slot != slot)
686 			continue;
687 
688 		ad4130_unlink_channel(st, i);
689 	}
690 
691 	return 0;
692 }
693 
694 static int ad4130_link_channel_slot(struct ad4130_state *st,
695 				    unsigned int channel, unsigned int slot)
696 {
697 	struct ad4130_slot_info *slot_info = &st->slots_info[slot];
698 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
699 	int ret;
700 
701 	ret = regmap_update_bits(st->regmap, AD4130_CHANNEL_X_REG(channel),
702 				 AD4130_CHANNEL_SETUP_MASK,
703 				 FIELD_PREP(AD4130_CHANNEL_SETUP_MASK, slot));
704 	if (ret)
705 		return ret;
706 
707 	chan_info->slot = slot;
708 	slot_info->channels++;
709 
710 	return 0;
711 }
712 
713 static int ad4130_write_slot_setup(struct ad4130_state *st,
714 				   unsigned int slot,
715 				   struct ad4130_setup_info *setup_info)
716 {
717 	unsigned int val;
718 	int ret;
719 
720 	val = FIELD_PREP(AD4130_CONFIG_IOUT1_VAL_MASK, setup_info->iout0_val) |
721 	      FIELD_PREP(AD4130_CONFIG_IOUT1_VAL_MASK, setup_info->iout1_val) |
722 	      FIELD_PREP(AD4130_CONFIG_BURNOUT_MASK, setup_info->burnout) |
723 	      FIELD_PREP(AD4130_CONFIG_REF_BUFP_MASK, setup_info->ref_bufp) |
724 	      FIELD_PREP(AD4130_CONFIG_REF_BUFM_MASK, setup_info->ref_bufm) |
725 	      FIELD_PREP(AD4130_CONFIG_REF_SEL_MASK, setup_info->ref_sel) |
726 	      FIELD_PREP(AD4130_CONFIG_PGA_MASK, setup_info->pga);
727 
728 	ret = regmap_write(st->regmap, AD4130_CONFIG_X_REG(slot), val);
729 	if (ret)
730 		return ret;
731 
732 	val = FIELD_PREP(AD4130_FILTER_MODE_MASK, setup_info->filter_type) |
733 	      FIELD_PREP(AD4130_FILTER_SELECT_MASK, setup_info->fs);
734 
735 	ret = regmap_write(st->regmap, AD4130_FILTER_X_REG(slot), val);
736 	if (ret)
737 		return ret;
738 
739 	memcpy(&st->slots_info[slot].setup, setup_info, sizeof(*setup_info));
740 
741 	return 0;
742 }
743 
744 static int ad4130_write_channel_setup(struct ad4130_state *st,
745 				      unsigned int channel, bool on_enable)
746 {
747 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
748 	struct ad4130_setup_info *setup_info = &chan_info->setup;
749 	bool overwrite;
750 	int slot;
751 	int ret;
752 
753 	/*
754 	 * The following cases need to be handled.
755 	 *
756 	 * 1. Enabled and linked channel with setup changes:
757 	 *    - Find a slot. If not possible, return error.
758 	 *    - Unlink channel from current slot.
759 	 *    - If the slot has channels linked to it, unlink all channels, and
760 	 *      write the new setup to it.
761 	 *    - Link channel to new slot.
762 	 *
763 	 * 2. Soon to be enabled and unlinked channel:
764 	 *    - Find a slot. If not possible, return error.
765 	 *    - If the slot has channels linked to it, unlink all channels, and
766 	 *      write the new setup to it.
767 	 *    - Link channel to the slot.
768 	 *
769 	 * 3. Disabled and linked channel with setup changes:
770 	 *    - Unlink channel from current slot.
771 	 *
772 	 * 4. Soon to be enabled and linked channel:
773 	 * 5. Disabled and unlinked channel with setup changes:
774 	 *    - Do nothing.
775 	 */
776 
777 	/* Case 4 */
778 	if (on_enable && chan_info->slot != AD4130_INVALID_SLOT)
779 		return 0;
780 
781 	if (!on_enable && !chan_info->enabled) {
782 		if (chan_info->slot != AD4130_INVALID_SLOT)
783 			/* Case 3 */
784 			ad4130_unlink_channel(st, channel);
785 
786 		/* Cases 3 & 5 */
787 		return 0;
788 	}
789 
790 	/* Cases 1 & 2 */
791 	ret = ad4130_find_slot(st, setup_info, &slot, &overwrite);
792 	if (ret)
793 		return ret;
794 
795 	if (chan_info->slot != AD4130_INVALID_SLOT)
796 		/* Case 1 */
797 		ad4130_unlink_channel(st, channel);
798 
799 	if (overwrite) {
800 		ret = ad4130_unlink_slot(st, slot);
801 		if (ret)
802 			return ret;
803 
804 		ret = ad4130_write_slot_setup(st, slot, setup_info);
805 		if (ret)
806 			return ret;
807 	}
808 
809 	return ad4130_link_channel_slot(st, channel, slot);
810 }
811 
812 static int ad4130_set_channel_enable(struct ad4130_state *st,
813 				     unsigned int channel, bool status)
814 {
815 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
816 	struct ad4130_slot_info *slot_info;
817 	int ret;
818 
819 	if (chan_info->enabled == status)
820 		return 0;
821 
822 	if (status) {
823 		ret = ad4130_write_channel_setup(st, channel, true);
824 		if (ret)
825 			return ret;
826 	}
827 
828 	slot_info = &st->slots_info[chan_info->slot];
829 
830 	ret = regmap_update_bits(st->regmap, AD4130_CHANNEL_X_REG(channel),
831 				 AD4130_CHANNEL_EN_MASK,
832 				 FIELD_PREP(AD4130_CHANNEL_EN_MASK, status));
833 	if (ret)
834 		return ret;
835 
836 	slot_info->enabled_channels += status ? 1 : -1;
837 	chan_info->enabled = status;
838 
839 	return 0;
840 }
841 
842 /*
843  * Table 58. FILTER_MODE_n bits and Filter Types of the datasheet describes
844  * the relation between filter mode, ODR and FS.
845  *
846  * Notice that the max ODR of each filter mode is not necessarily the
847  * absolute max ODR supported by the chip.
848  *
849  * The ODR divider is not explicitly specified, but it can be deduced based
850  * on the ODR range of each filter mode.
851  *
852  * For example, for Sinc4+Sinc1, max ODR is 218.18. That means that the
853  * absolute max ODR is divided by 11 to achieve the max ODR of this filter
854  * mode.
855  *
856  * The formulas for converting between ODR and FS for a specific filter
857  * mode can be deduced from the same table.
858  *
859  * Notice that FS = 1 actually means max ODR, and that ODR decreases by
860  * (maximum ODR / maximum FS) for each increment of FS.
861  *
862  * odr = MAX_ODR / odr_div * (1 - (fs - 1) / fs_max) <=>
863  * odr = MAX_ODR * (1 - (fs - 1) / fs_max) / odr_div <=>
864  * odr = MAX_ODR * (1 - (fs - 1) / fs_max) / odr_div <=>
865  * odr = MAX_ODR * (fs_max - fs + 1) / (fs_max * odr_div)
866  * (used in ad4130_fs_to_freq)
867  *
868  * For the opposite formula, FS can be extracted from the last one.
869  *
870  * MAX_ODR * (fs_max - fs + 1) = fs_max * odr_div * odr <=>
871  * fs_max - fs + 1 = fs_max * odr_div * odr / MAX_ODR <=>
872  * fs = 1 + fs_max - fs_max * odr_div * odr / MAX_ODR
873  * (used in ad4130_fs_to_freq)
874  */
875 
876 static void ad4130_freq_to_fs(enum ad4130_filter_type filter_type,
877 			      int val, int val2, unsigned int *fs)
878 {
879 	const struct ad4130_filter_config *filter_config =
880 		&ad4130_filter_configs[filter_type];
881 	u64 dividend, divisor;
882 	int temp;
883 
884 	dividend = filter_config->fs_max * filter_config->odr_div *
885 		   ((u64)val * NANO + val2);
886 	divisor = (u64)AD4130_MAX_ODR * NANO;
887 
888 	temp = AD4130_FILTER_SELECT_MIN + filter_config->fs_max -
889 	       DIV64_U64_ROUND_CLOSEST(dividend, divisor);
890 
891 	if (temp < AD4130_FILTER_SELECT_MIN)
892 		temp = AD4130_FILTER_SELECT_MIN;
893 	else if (temp > filter_config->fs_max)
894 		temp = filter_config->fs_max;
895 
896 	*fs = temp;
897 }
898 
899 static void ad4130_fs_to_freq(enum ad4130_filter_type filter_type,
900 			      unsigned int fs, int *val, int *val2)
901 {
902 	const struct ad4130_filter_config *filter_config =
903 		&ad4130_filter_configs[filter_type];
904 	unsigned int dividend, divisor;
905 	u64 temp;
906 
907 	dividend = (filter_config->fs_max - fs + AD4130_FILTER_SELECT_MIN) *
908 		   AD4130_MAX_ODR;
909 	divisor = filter_config->fs_max * filter_config->odr_div;
910 
911 	temp = div_u64((u64)dividend * NANO, divisor);
912 	*val = div_u64_rem(temp, NANO, val2);
913 }
914 
915 static int ad4130_set_filter_type(struct iio_dev *indio_dev,
916 				  const struct iio_chan_spec *chan,
917 				  unsigned int val)
918 {
919 	struct ad4130_state *st = iio_priv(indio_dev);
920 	unsigned int channel = chan->scan_index;
921 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
922 	struct ad4130_setup_info *setup_info = &chan_info->setup;
923 	enum ad4130_filter_type old_filter_type;
924 	int freq_val, freq_val2;
925 	unsigned int old_fs;
926 	int ret = 0;
927 
928 	guard(mutex)(&st->lock);
929 	if (setup_info->filter_type == val)
930 		return 0;
931 
932 	old_fs = setup_info->fs;
933 	old_filter_type = setup_info->filter_type;
934 
935 	/*
936 	 * When switching between filter modes, try to match the ODR as
937 	 * close as possible. To do this, convert the current FS into ODR
938 	 * using the old filter mode, then convert it back into FS using
939 	 * the new filter mode.
940 	 */
941 	ad4130_fs_to_freq(setup_info->filter_type, setup_info->fs,
942 			  &freq_val, &freq_val2);
943 
944 	ad4130_freq_to_fs(val, freq_val, freq_val2, &setup_info->fs);
945 
946 	setup_info->filter_type = val;
947 
948 	ret = ad4130_write_channel_setup(st, channel, false);
949 	if (ret) {
950 		setup_info->fs = old_fs;
951 		setup_info->filter_type = old_filter_type;
952 		return ret;
953 	}
954 
955 	return 0;
956 }
957 
958 static int ad4130_get_filter_type(struct iio_dev *indio_dev,
959 				  const struct iio_chan_spec *chan)
960 {
961 	struct ad4130_state *st = iio_priv(indio_dev);
962 	unsigned int channel = chan->scan_index;
963 	struct ad4130_setup_info *setup_info = &st->chans_info[channel].setup;
964 	enum ad4130_filter_type filter_type;
965 
966 	guard(mutex)(&st->lock);
967 	filter_type = setup_info->filter_type;
968 
969 	return filter_type;
970 }
971 
972 static const struct iio_enum ad4130_filter_type_enum = {
973 	.items = ad4130_filter_types_str,
974 	.num_items = ARRAY_SIZE(ad4130_filter_types_str),
975 	.set = ad4130_set_filter_type,
976 	.get = ad4130_get_filter_type,
977 };
978 
979 static const struct iio_chan_spec_ext_info ad4130_ext_info[] = {
980 	/*
981 	 * `filter_type` is the standardized IIO ABI for digital filtering.
982 	 * `filter_mode` is just kept for backwards compatibility.
983 	 */
984 	IIO_ENUM("filter_mode", IIO_SEPARATE, &ad4130_filter_type_enum),
985 	IIO_ENUM_AVAILABLE("filter_mode", IIO_SHARED_BY_TYPE,
986 			   &ad4130_filter_type_enum),
987 	IIO_ENUM("filter_type", IIO_SEPARATE, &ad4130_filter_type_enum),
988 	IIO_ENUM_AVAILABLE("filter_type", IIO_SHARED_BY_TYPE,
989 			   &ad4130_filter_type_enum),
990 	{ }
991 };
992 
993 static const struct iio_chan_spec ad4130_channel_template = {
994 	.type = IIO_VOLTAGE,
995 	.indexed = 1,
996 	.differential = 1,
997 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
998 			      BIT(IIO_CHAN_INFO_SCALE) |
999 			      BIT(IIO_CHAN_INFO_OFFSET) |
1000 			      BIT(IIO_CHAN_INFO_SAMP_FREQ),
1001 	.info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE) |
1002 					BIT(IIO_CHAN_INFO_SAMP_FREQ),
1003 	.ext_info = ad4130_ext_info,
1004 	.scan_type = {
1005 		.sign = 'u',
1006 		.endianness = IIO_BE,
1007 	},
1008 };
1009 
1010 static int ad4130_set_channel_pga(struct ad4130_state *st, unsigned int channel,
1011 				  int val, int val2)
1012 {
1013 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
1014 	struct ad4130_setup_info *setup_info = &chan_info->setup;
1015 	unsigned int pga, old_pga;
1016 	int ret;
1017 
1018 	for (pga = 0; pga < AD4130_MAX_PGA; pga++)
1019 		if (val == st->scale_tbls[setup_info->ref_sel][pga][0] &&
1020 		    val2 == st->scale_tbls[setup_info->ref_sel][pga][1])
1021 			break;
1022 
1023 	if (pga == AD4130_MAX_PGA)
1024 		return -EINVAL;
1025 
1026 	guard(mutex)(&st->lock);
1027 	if (pga == setup_info->pga)
1028 		return 0;
1029 
1030 	old_pga = setup_info->pga;
1031 	setup_info->pga = pga;
1032 
1033 	ret = ad4130_write_channel_setup(st, channel, false);
1034 	if (ret) {
1035 		setup_info->pga = old_pga;
1036 		return ret;
1037 	}
1038 
1039 	return 0;
1040 }
1041 
1042 static int ad4130_set_channel_freq(struct ad4130_state *st,
1043 				   unsigned int channel, int val, int val2)
1044 {
1045 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
1046 	struct ad4130_setup_info *setup_info = &chan_info->setup;
1047 	unsigned int fs, old_fs;
1048 	int ret;
1049 
1050 	guard(mutex)(&st->lock);
1051 	old_fs = setup_info->fs;
1052 
1053 	ad4130_freq_to_fs(setup_info->filter_type, val, val2, &fs);
1054 
1055 	if (fs == setup_info->fs)
1056 		return 0;
1057 
1058 	setup_info->fs = fs;
1059 
1060 	ret = ad4130_write_channel_setup(st, channel, false);
1061 	if (ret) {
1062 		setup_info->fs = old_fs;
1063 		return ret;
1064 	}
1065 
1066 	return 0;
1067 }
1068 
1069 static int _ad4130_read_sample(struct iio_dev *indio_dev, unsigned int channel,
1070 			       int *val)
1071 {
1072 	struct ad4130_state *st = iio_priv(indio_dev);
1073 	int ret;
1074 
1075 	ret = ad4130_set_channel_enable(st, channel, true);
1076 	if (ret)
1077 		return ret;
1078 
1079 	reinit_completion(&st->completion);
1080 
1081 	ret = ad4130_set_mode(st, AD4130_MODE_CONTINUOUS);
1082 	if (ret)
1083 		return ret;
1084 
1085 	ret = wait_for_completion_timeout(&st->completion,
1086 					  msecs_to_jiffies(1000));
1087 	if (!ret)
1088 		return -ETIMEDOUT;
1089 
1090 	ret = ad4130_set_mode(st, AD4130_MODE_IDLE);
1091 	if (ret)
1092 		return ret;
1093 
1094 	ret = regmap_read(st->regmap, AD4130_DATA_REG, val);
1095 	if (ret)
1096 		return ret;
1097 
1098 	ret = ad4130_set_channel_enable(st, channel, false);
1099 	if (ret)
1100 		return ret;
1101 
1102 	return IIO_VAL_INT;
1103 }
1104 
1105 static int ad4130_read_sample(struct iio_dev *indio_dev, unsigned int channel,
1106 			      int *val)
1107 {
1108 	struct ad4130_state *st = iio_priv(indio_dev);
1109 
1110 	guard(mutex)(&st->lock);
1111 
1112 	return _ad4130_read_sample(indio_dev, channel, val);
1113 }
1114 
1115 static int ad4130_read_raw(struct iio_dev *indio_dev,
1116 			   struct iio_chan_spec const *chan,
1117 			   int *val, int *val2, long info)
1118 {
1119 	struct ad4130_state *st = iio_priv(indio_dev);
1120 	unsigned int channel = chan->scan_index;
1121 	struct ad4130_setup_info *setup_info = &st->chans_info[channel].setup;
1122 	int ret;
1123 
1124 	switch (info) {
1125 	case IIO_CHAN_INFO_RAW:
1126 		if (!iio_device_claim_direct(indio_dev))
1127 			return -EBUSY;
1128 
1129 		ret = ad4130_read_sample(indio_dev, channel, val);
1130 		iio_device_release_direct(indio_dev);
1131 		return ret;
1132 	case IIO_CHAN_INFO_SCALE: {
1133 		guard(mutex)(&st->lock);
1134 		*val = st->scale_tbls[setup_info->ref_sel][setup_info->pga][0];
1135 		*val2 = st->scale_tbls[setup_info->ref_sel][setup_info->pga][1];
1136 
1137 		return IIO_VAL_INT_PLUS_NANO;
1138 	}
1139 	case IIO_CHAN_INFO_OFFSET:
1140 		*val = st->bipolar ? -BIT(chan->scan_type.realbits - 1) : 0;
1141 
1142 		return IIO_VAL_INT;
1143 	case IIO_CHAN_INFO_SAMP_FREQ: {
1144 		guard(mutex)(&st->lock);
1145 		ad4130_fs_to_freq(setup_info->filter_type, setup_info->fs,
1146 				  val, val2);
1147 
1148 		return IIO_VAL_INT_PLUS_NANO;
1149 	}
1150 	default:
1151 		return -EINVAL;
1152 	}
1153 }
1154 
1155 static int ad4130_read_avail(struct iio_dev *indio_dev,
1156 			     struct iio_chan_spec const *chan,
1157 			     const int **vals, int *type, int *length,
1158 			     long info)
1159 {
1160 	struct ad4130_state *st = iio_priv(indio_dev);
1161 	unsigned int channel = chan->scan_index;
1162 	struct ad4130_setup_info *setup_info = &st->chans_info[channel].setup;
1163 	const struct ad4130_filter_config *filter_config;
1164 
1165 	switch (info) {
1166 	case IIO_CHAN_INFO_SCALE:
1167 		*vals = (int *)st->scale_tbls[setup_info->ref_sel];
1168 		*length = ARRAY_SIZE(st->scale_tbls[setup_info->ref_sel]) * 2;
1169 
1170 		*type = IIO_VAL_INT_PLUS_NANO;
1171 
1172 		return IIO_AVAIL_LIST;
1173 	case IIO_CHAN_INFO_SAMP_FREQ:
1174 		scoped_guard(mutex, &st->lock) {
1175 			filter_config = &ad4130_filter_configs[setup_info->filter_type];
1176 		}
1177 
1178 		*vals = (int *)filter_config->samp_freq_avail;
1179 		*length = filter_config->samp_freq_avail_len * 2;
1180 		*type = IIO_VAL_FRACTIONAL;
1181 
1182 		return filter_config->samp_freq_avail_type;
1183 	default:
1184 		return -EINVAL;
1185 	}
1186 }
1187 
1188 static int ad4130_write_raw_get_fmt(struct iio_dev *indio_dev,
1189 				    struct iio_chan_spec const *chan,
1190 				    long info)
1191 {
1192 	switch (info) {
1193 	case IIO_CHAN_INFO_SCALE:
1194 	case IIO_CHAN_INFO_SAMP_FREQ:
1195 		return IIO_VAL_INT_PLUS_NANO;
1196 	default:
1197 		return -EINVAL;
1198 	}
1199 }
1200 
1201 static int ad4130_write_raw(struct iio_dev *indio_dev,
1202 			    struct iio_chan_spec const *chan,
1203 			    int val, int val2, long info)
1204 {
1205 	struct ad4130_state *st = iio_priv(indio_dev);
1206 	unsigned int channel = chan->scan_index;
1207 
1208 	switch (info) {
1209 	case IIO_CHAN_INFO_SCALE:
1210 		return ad4130_set_channel_pga(st, channel, val, val2);
1211 	case IIO_CHAN_INFO_SAMP_FREQ:
1212 		return ad4130_set_channel_freq(st, channel, val, val2);
1213 	default:
1214 		return -EINVAL;
1215 	}
1216 }
1217 
1218 static int ad4130_reg_access(struct iio_dev *indio_dev, unsigned int reg,
1219 			     unsigned int writeval, unsigned int *readval)
1220 {
1221 	struct ad4130_state *st = iio_priv(indio_dev);
1222 
1223 	if (readval)
1224 		return regmap_read(st->regmap, reg, readval);
1225 
1226 	return regmap_write(st->regmap, reg, writeval);
1227 }
1228 
1229 static int ad4130_update_scan_mode(struct iio_dev *indio_dev,
1230 				   const unsigned long *scan_mask)
1231 {
1232 	struct ad4130_state *st = iio_priv(indio_dev);
1233 	unsigned int channel;
1234 	unsigned int val = 0;
1235 	int ret;
1236 
1237 	guard(mutex)(&st->lock);
1238 
1239 	for_each_set_bit(channel, scan_mask, indio_dev->num_channels) {
1240 		ret = ad4130_set_channel_enable(st, channel, true);
1241 		if (ret)
1242 			return ret;
1243 
1244 		val++;
1245 	}
1246 
1247 	st->num_enabled_channels = val;
1248 
1249 	return 0;
1250 }
1251 
1252 static int ad4130_set_fifo_watermark(struct iio_dev *indio_dev, unsigned int val)
1253 {
1254 	struct ad4130_state *st = iio_priv(indio_dev);
1255 	unsigned int eff;
1256 	int ret;
1257 
1258 	if (val > AD4130_FIFO_SIZE)
1259 		return -EINVAL;
1260 
1261 	eff = val * st->num_enabled_channels;
1262 	if (eff > AD4130_FIFO_SIZE)
1263 		/*
1264 		 * Always set watermark to a multiple of the number of
1265 		 * enabled channels to avoid making the FIFO unaligned.
1266 		 */
1267 		eff = rounddown(AD4130_FIFO_SIZE, st->num_enabled_channels);
1268 
1269 	guard(mutex)(&st->lock);
1270 
1271 	ret = regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
1272 				 AD4130_FIFO_CONTROL_WM_MASK,
1273 				 FIELD_PREP(AD4130_FIFO_CONTROL_WM_MASK,
1274 					    ad4130_watermark_reg_val(eff)));
1275 	if (ret)
1276 		return ret;
1277 
1278 	st->effective_watermark = eff;
1279 	st->watermark = val;
1280 
1281 	return 0;
1282 }
1283 
1284 static const struct iio_info ad4130_info = {
1285 	.read_raw = ad4130_read_raw,
1286 	.read_avail = ad4130_read_avail,
1287 	.write_raw_get_fmt = ad4130_write_raw_get_fmt,
1288 	.write_raw = ad4130_write_raw,
1289 	.update_scan_mode = ad4130_update_scan_mode,
1290 	.hwfifo_set_watermark = ad4130_set_fifo_watermark,
1291 	.debugfs_reg_access = ad4130_reg_access,
1292 };
1293 
1294 static int ad4130_buffer_postenable(struct iio_dev *indio_dev)
1295 {
1296 	struct ad4130_state *st = iio_priv(indio_dev);
1297 	int ret;
1298 
1299 	guard(mutex)(&st->lock);
1300 
1301 	ret = ad4130_set_watermark_interrupt_en(st, true);
1302 	if (ret)
1303 		return ret;
1304 
1305 	ret = irq_set_irq_type(st->spi->irq, st->inv_irq_trigger);
1306 	if (ret)
1307 		return ret;
1308 
1309 	ret = ad4130_set_fifo_mode(st, AD4130_FIFO_MODE_WM);
1310 	if (ret)
1311 		return ret;
1312 
1313 	return ad4130_set_mode(st, AD4130_MODE_CONTINUOUS);
1314 }
1315 
1316 static int ad4130_buffer_predisable(struct iio_dev *indio_dev)
1317 {
1318 	struct ad4130_state *st = iio_priv(indio_dev);
1319 	unsigned int i;
1320 	int ret;
1321 
1322 	guard(mutex)(&st->lock);
1323 
1324 	ret = ad4130_set_mode(st, AD4130_MODE_IDLE);
1325 	if (ret)
1326 		return ret;
1327 
1328 	ret = irq_set_irq_type(st->spi->irq, st->irq_trigger);
1329 	if (ret)
1330 		return ret;
1331 
1332 	ret = ad4130_set_fifo_mode(st, AD4130_FIFO_MODE_DISABLED);
1333 	if (ret)
1334 		return ret;
1335 
1336 	ret = ad4130_set_watermark_interrupt_en(st, false);
1337 	if (ret)
1338 		return ret;
1339 
1340 	/*
1341 	 * update_scan_mode() is not called in the disable path, disable all
1342 	 * channels here.
1343 	 */
1344 	for (i = 0; i < indio_dev->num_channels; i++) {
1345 		ret = ad4130_set_channel_enable(st, i, false);
1346 		if (ret)
1347 			return ret;
1348 	}
1349 
1350 	return 0;
1351 }
1352 
1353 static const struct iio_buffer_setup_ops ad4130_buffer_ops = {
1354 	.postenable = ad4130_buffer_postenable,
1355 	.predisable = ad4130_buffer_predisable,
1356 };
1357 
1358 static ssize_t hwfifo_watermark_show(struct device *dev,
1359 				     struct device_attribute *attr, char *buf)
1360 {
1361 	struct ad4130_state *st = iio_priv(dev_to_iio_dev(dev));
1362 	unsigned int val;
1363 
1364 	guard(mutex)(&st->lock);
1365 	val = st->watermark;
1366 
1367 	return sysfs_emit(buf, "%d\n", val);
1368 }
1369 
1370 static ssize_t hwfifo_enabled_show(struct device *dev,
1371 				   struct device_attribute *attr, char *buf)
1372 {
1373 	struct ad4130_state *st = iio_priv(dev_to_iio_dev(dev));
1374 	unsigned int val;
1375 	int ret;
1376 
1377 	ret = regmap_read(st->regmap, AD4130_FIFO_CONTROL_REG, &val);
1378 	if (ret)
1379 		return ret;
1380 
1381 	val = FIELD_GET(AD4130_FIFO_CONTROL_MODE_MASK, val);
1382 
1383 	return sysfs_emit(buf, "%d\n", val != AD4130_FIFO_MODE_DISABLED);
1384 }
1385 
1386 static ssize_t hwfifo_watermark_min_show(struct device *dev,
1387 					 struct device_attribute *attr,
1388 					 char *buf)
1389 {
1390 	return sysfs_emit(buf, "%s\n", "1");
1391 }
1392 
1393 static ssize_t hwfifo_watermark_max_show(struct device *dev,
1394 					 struct device_attribute *attr,
1395 					 char *buf)
1396 {
1397 	return sysfs_emit(buf, "%s\n", __stringify(AD4130_FIFO_SIZE));
1398 }
1399 
1400 static IIO_DEVICE_ATTR_RO(hwfifo_watermark_min, 0);
1401 static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0);
1402 static IIO_DEVICE_ATTR_RO(hwfifo_watermark, 0);
1403 static IIO_DEVICE_ATTR_RO(hwfifo_enabled, 0);
1404 
1405 static const struct iio_dev_attr *ad4130_fifo_attributes[] = {
1406 	&iio_dev_attr_hwfifo_watermark_min,
1407 	&iio_dev_attr_hwfifo_watermark_max,
1408 	&iio_dev_attr_hwfifo_watermark,
1409 	&iio_dev_attr_hwfifo_enabled,
1410 	NULL
1411 };
1412 
1413 static int _ad4130_find_table_index(const unsigned int *tbl, size_t len,
1414 				    unsigned int val)
1415 {
1416 	unsigned int i;
1417 
1418 	for (i = 0; i < len; i++)
1419 		if (tbl[i] == val)
1420 			return i;
1421 
1422 	return -EINVAL;
1423 }
1424 
1425 #define ad4130_find_table_index(table, val) \
1426 	_ad4130_find_table_index(table, ARRAY_SIZE(table), val)
1427 
1428 static int ad4130_get_ref_voltage(struct ad4130_state *st,
1429 				  enum ad4130_ref_sel ref_sel)
1430 {
1431 	switch (ref_sel) {
1432 	case AD4130_REF_REFIN1:
1433 		return regulator_get_voltage(st->regulators[2].consumer);
1434 	case AD4130_REF_REFIN2:
1435 		return regulator_get_voltage(st->regulators[3].consumer);
1436 	case AD4130_REF_AVDD_AVSS:
1437 		return regulator_get_voltage(st->regulators[0].consumer);
1438 	case AD4130_REF_REFOUT_AVSS:
1439 		return st->int_ref_uv;
1440 	default:
1441 		return -EINVAL;
1442 	}
1443 }
1444 
1445 static int ad4130_parse_fw_setup(struct ad4130_state *st,
1446 				 struct fwnode_handle *child,
1447 				 struct ad4130_setup_info *setup_info)
1448 {
1449 	struct device *dev = &st->spi->dev;
1450 	u32 tmp;
1451 	int ret;
1452 
1453 	tmp = 0;
1454 	fwnode_property_read_u32(child, "adi,excitation-current-0-nanoamp", &tmp);
1455 	ret = ad4130_find_table_index(ad4130_iout_current_na_tbl, tmp);
1456 	if (ret < 0)
1457 		return dev_err_probe(dev, ret,
1458 				     "Invalid excitation current %unA\n", tmp);
1459 	setup_info->iout0_val = ret;
1460 
1461 	tmp = 0;
1462 	fwnode_property_read_u32(child, "adi,excitation-current-1-nanoamp", &tmp);
1463 	ret = ad4130_find_table_index(ad4130_iout_current_na_tbl, tmp);
1464 	if (ret < 0)
1465 		return dev_err_probe(dev, ret,
1466 				     "Invalid excitation current %unA\n", tmp);
1467 	setup_info->iout1_val = ret;
1468 
1469 	tmp = 0;
1470 	fwnode_property_read_u32(child, "adi,burnout-current-nanoamp", &tmp);
1471 	ret = ad4130_find_table_index(ad4130_burnout_current_na_tbl, tmp);
1472 	if (ret < 0)
1473 		return dev_err_probe(dev, ret,
1474 				     "Invalid burnout current %unA\n", tmp);
1475 	setup_info->burnout = ret;
1476 
1477 	setup_info->ref_bufp = fwnode_property_read_bool(child, "adi,buffered-positive");
1478 	setup_info->ref_bufm = fwnode_property_read_bool(child, "adi,buffered-negative");
1479 
1480 	setup_info->ref_sel = AD4130_REF_REFIN1;
1481 	fwnode_property_read_u32(child, "adi,reference-select",
1482 				 &setup_info->ref_sel);
1483 	if (setup_info->ref_sel >= AD4130_REF_SEL_MAX)
1484 		return dev_err_probe(dev, -EINVAL,
1485 				     "Invalid reference selected %u\n",
1486 				     setup_info->ref_sel);
1487 
1488 	if (setup_info->ref_sel == AD4130_REF_REFOUT_AVSS)
1489 		st->int_ref_en = true;
1490 
1491 	ret = ad4130_get_ref_voltage(st, setup_info->ref_sel);
1492 	if (ret < 0)
1493 		return dev_err_probe(dev, ret, "Cannot use reference %u\n",
1494 				     setup_info->ref_sel);
1495 
1496 	return 0;
1497 }
1498 
1499 static int ad4130_validate_diff_channel(struct ad4130_state *st, u32 pin)
1500 {
1501 	struct device *dev = &st->spi->dev;
1502 
1503 	if (pin >= AD4130_MAX_DIFF_INPUTS)
1504 		return dev_err_probe(dev, -EINVAL,
1505 				     "Invalid differential channel %u\n", pin);
1506 
1507 	if (pin >= AD4130_MAX_ANALOG_PINS)
1508 		return 0;
1509 
1510 	if (st->pins_fn[pin] == AD4130_PIN_FN_SPECIAL)
1511 		return dev_err_probe(dev, -EINVAL,
1512 				     "Pin %u already used with fn %u\n", pin,
1513 				     st->pins_fn[pin]);
1514 
1515 	st->pins_fn[pin] |= AD4130_PIN_FN_DIFF;
1516 
1517 	return 0;
1518 }
1519 
1520 static int ad4130_validate_diff_channels(struct ad4130_state *st,
1521 					 u32 *pins, unsigned int len)
1522 {
1523 	unsigned int i;
1524 	int ret;
1525 
1526 	for (i = 0; i < len; i++) {
1527 		ret = ad4130_validate_diff_channel(st, pins[i]);
1528 		if (ret)
1529 			return ret;
1530 	}
1531 
1532 	return 0;
1533 }
1534 
1535 static int ad4130_validate_excitation_pin(struct ad4130_state *st, u32 pin)
1536 {
1537 	struct device *dev = &st->spi->dev;
1538 
1539 	if (pin >= AD4130_MAX_ANALOG_PINS)
1540 		return dev_err_probe(dev, -EINVAL,
1541 				     "Invalid excitation pin %u\n", pin);
1542 
1543 	if (st->pins_fn[pin] == AD4130_PIN_FN_SPECIAL)
1544 		return dev_err_probe(dev, -EINVAL,
1545 				     "Pin %u already used with fn %u\n", pin,
1546 				     st->pins_fn[pin]);
1547 
1548 	st->pins_fn[pin] |= AD4130_PIN_FN_EXCITATION;
1549 
1550 	return 0;
1551 }
1552 
1553 static int ad4130_validate_vbias_pin(struct ad4130_state *st, u32 pin)
1554 {
1555 	struct device *dev = &st->spi->dev;
1556 
1557 	if (pin >= AD4130_MAX_ANALOG_PINS)
1558 		return dev_err_probe(dev, -EINVAL, "Invalid vbias pin %u\n",
1559 				     pin);
1560 
1561 	if (st->pins_fn[pin] == AD4130_PIN_FN_SPECIAL)
1562 		return dev_err_probe(dev, -EINVAL,
1563 				     "Pin %u already used with fn %u\n", pin,
1564 				     st->pins_fn[pin]);
1565 
1566 	st->pins_fn[pin] |= AD4130_PIN_FN_VBIAS;
1567 
1568 	return 0;
1569 }
1570 
1571 static int ad4130_validate_vbias_pins(struct ad4130_state *st,
1572 				      u32 *pins, unsigned int len)
1573 {
1574 	unsigned int i;
1575 	int ret;
1576 
1577 	for (i = 0; i < st->num_vbias_pins; i++) {
1578 		ret = ad4130_validate_vbias_pin(st, pins[i]);
1579 		if (ret)
1580 			return ret;
1581 	}
1582 
1583 	return 0;
1584 }
1585 
1586 static int ad4130_parse_fw_channel(struct iio_dev *indio_dev,
1587 				   struct fwnode_handle *child)
1588 {
1589 	struct ad4130_state *st = iio_priv(indio_dev);
1590 	unsigned int resolution = ad4130_resolution(st);
1591 	unsigned int index = indio_dev->num_channels++;
1592 	struct device *dev = &st->spi->dev;
1593 	struct ad4130_chan_info *chan_info;
1594 	struct iio_chan_spec *chan;
1595 	u32 pins[2];
1596 	int ret;
1597 
1598 	if (index >= AD4130_MAX_CHANNELS)
1599 		return dev_err_probe(dev, -EINVAL, "Too many channels\n");
1600 
1601 	chan = &st->chans[index];
1602 	chan_info = &st->chans_info[index];
1603 
1604 	*chan = ad4130_channel_template;
1605 	chan->scan_type.realbits = resolution;
1606 	chan->scan_type.storagebits = resolution;
1607 	chan->scan_index = index;
1608 
1609 	chan_info->slot = AD4130_INVALID_SLOT;
1610 	chan_info->setup.fs = AD4130_FILTER_SELECT_MIN;
1611 	chan_info->initialized = true;
1612 
1613 	ret = fwnode_property_read_u32_array(child, "diff-channels", pins,
1614 					     ARRAY_SIZE(pins));
1615 	if (ret)
1616 		return ret;
1617 
1618 	ret = ad4130_validate_diff_channels(st, pins, ARRAY_SIZE(pins));
1619 	if (ret)
1620 		return ret;
1621 
1622 	chan->channel = pins[0];
1623 	chan->channel2 = pins[1];
1624 
1625 	ret = ad4130_parse_fw_setup(st, child, &chan_info->setup);
1626 	if (ret)
1627 		return ret;
1628 
1629 	fwnode_property_read_u32(child, "adi,excitation-pin-0",
1630 				 &chan_info->iout0);
1631 	if (chan_info->setup.iout0_val != AD4130_IOUT_OFF) {
1632 		ret = ad4130_validate_excitation_pin(st, chan_info->iout0);
1633 		if (ret)
1634 			return ret;
1635 	}
1636 
1637 	fwnode_property_read_u32(child, "adi,excitation-pin-1",
1638 				 &chan_info->iout1);
1639 	if (chan_info->setup.iout1_val != AD4130_IOUT_OFF) {
1640 		ret = ad4130_validate_excitation_pin(st, chan_info->iout1);
1641 		if (ret)
1642 			return ret;
1643 	}
1644 
1645 	return 0;
1646 }
1647 
1648 static int ad4130_parse_fw_children(struct iio_dev *indio_dev)
1649 {
1650 	struct ad4130_state *st = iio_priv(indio_dev);
1651 	struct device *dev = &st->spi->dev;
1652 	int ret;
1653 
1654 	indio_dev->channels = st->chans;
1655 
1656 	device_for_each_child_node_scoped(dev, child) {
1657 		ret = ad4130_parse_fw_channel(indio_dev, child);
1658 		if (ret)
1659 			return ret;
1660 	}
1661 
1662 	return 0;
1663 }
1664 
1665 static int ad4310_parse_fw(struct iio_dev *indio_dev)
1666 {
1667 	struct ad4130_state *st = iio_priv(indio_dev);
1668 	struct device *dev = &st->spi->dev;
1669 	u32 ext_clk_freq = AD4130_MCLK_FREQ_76_8KHZ;
1670 	unsigned int i;
1671 	int avdd_uv;
1672 	int irq;
1673 	int ret;
1674 
1675 	st->mclk = devm_clk_get_optional(dev, "mclk");
1676 	if (IS_ERR(st->mclk))
1677 		return dev_err_probe(dev, PTR_ERR(st->mclk),
1678 				     "Failed to get mclk\n");
1679 
1680 	st->int_pin_sel = AD4130_INT_PIN_INT;
1681 
1682 	for (i = 0; i < ARRAY_SIZE(ad4130_int_pin_names); i++) {
1683 		irq = fwnode_irq_get_byname(dev_fwnode(dev),
1684 					    ad4130_int_pin_names[i]);
1685 		if (irq > 0) {
1686 			st->int_pin_sel = i;
1687 			break;
1688 		}
1689 	}
1690 
1691 	if (st->int_pin_sel == AD4130_INT_PIN_DOUT)
1692 		return dev_err_probe(dev, -EINVAL,
1693 				     "Cannot use DOUT as interrupt pin\n");
1694 
1695 	if (st->int_pin_sel == AD4130_INT_PIN_P2)
1696 		st->pins_fn[AD4130_AIN3_P2] = AD4130_PIN_FN_SPECIAL;
1697 
1698 	device_property_read_u32(dev, "adi,ext-clk-freq-hz", &ext_clk_freq);
1699 	if (ext_clk_freq != AD4130_MCLK_FREQ_153_6KHZ &&
1700 	    ext_clk_freq != AD4130_MCLK_FREQ_76_8KHZ)
1701 		return dev_err_probe(dev, -EINVAL,
1702 				     "Invalid external clock frequency %u\n",
1703 				     ext_clk_freq);
1704 
1705 	if (st->mclk && ext_clk_freq == AD4130_MCLK_FREQ_153_6KHZ)
1706 		st->mclk_sel = AD4130_MCLK_153_6KHZ_EXT;
1707 	else if (st->mclk)
1708 		st->mclk_sel = AD4130_MCLK_76_8KHZ_EXT;
1709 	else
1710 		st->mclk_sel = AD4130_MCLK_76_8KHZ;
1711 
1712 	if (st->int_pin_sel == AD4130_INT_PIN_CLK &&
1713 	    st->mclk_sel != AD4130_MCLK_76_8KHZ)
1714 		return dev_err_probe(dev, -EINVAL,
1715 				     "Invalid clock %u for interrupt pin %u\n",
1716 				     st->mclk_sel, st->int_pin_sel);
1717 
1718 	st->int_ref_uv = AD4130_INT_REF_2_5V;
1719 
1720 	/*
1721 	 * When the AVDD supply is set to below 2.5V the internal reference of
1722 	 * 1.25V should be selected.
1723 	 * See datasheet page 37, section ADC REFERENCE.
1724 	 */
1725 	avdd_uv = regulator_get_voltage(st->regulators[0].consumer);
1726 	if (avdd_uv > 0 && avdd_uv < AD4130_INT_REF_2_5V)
1727 		st->int_ref_uv = AD4130_INT_REF_1_25V;
1728 
1729 	st->bipolar = device_property_read_bool(dev, "adi,bipolar");
1730 
1731 	ret = device_property_count_u32(dev, "adi,vbias-pins");
1732 	if (ret > 0) {
1733 		if (ret > AD4130_MAX_ANALOG_PINS)
1734 			return dev_err_probe(dev, -EINVAL,
1735 					     "Too many vbias pins %u\n", ret);
1736 
1737 		st->num_vbias_pins = ret;
1738 
1739 		ret = device_property_read_u32_array(dev, "adi,vbias-pins",
1740 						     st->vbias_pins,
1741 						     st->num_vbias_pins);
1742 		if (ret)
1743 			return dev_err_probe(dev, ret,
1744 					     "Failed to read vbias pins\n");
1745 
1746 		ret = ad4130_validate_vbias_pins(st, st->vbias_pins,
1747 						 st->num_vbias_pins);
1748 		if (ret)
1749 			return ret;
1750 	}
1751 
1752 	ret = ad4130_parse_fw_children(indio_dev);
1753 	if (ret)
1754 		return ret;
1755 
1756 	return 0;
1757 }
1758 
1759 static void ad4130_fill_scale_tbls(struct ad4130_state *st)
1760 {
1761 	unsigned int pow = ad4130_resolution(st) - st->bipolar;
1762 	unsigned int i, j;
1763 
1764 	for (i = 0; i < AD4130_REF_SEL_MAX; i++) {
1765 		int ret;
1766 		u64 nv;
1767 
1768 		ret = ad4130_get_ref_voltage(st, i);
1769 		if (ret < 0)
1770 			continue;
1771 
1772 		nv = (u64)ret * NANO;
1773 
1774 		for (j = 0; j < AD4130_MAX_PGA; j++)
1775 			st->scale_tbls[i][j][1] = div_u64(nv >> (pow + j), MILLI);
1776 	}
1777 }
1778 
1779 static void ad4130_clk_disable_unprepare(void *clk)
1780 {
1781 	clk_disable_unprepare(clk);
1782 }
1783 
1784 static int ad4130_set_mclk_sel(struct ad4130_state *st,
1785 			       enum ad4130_mclk_sel mclk_sel)
1786 {
1787 	return regmap_update_bits(st->regmap, AD4130_ADC_CONTROL_REG,
1788 				 AD4130_ADC_CONTROL_MCLK_SEL_MASK,
1789 				 FIELD_PREP(AD4130_ADC_CONTROL_MCLK_SEL_MASK,
1790 					    mclk_sel));
1791 }
1792 
1793 static unsigned long ad4130_int_clk_recalc_rate(struct clk_hw *hw,
1794 						unsigned long parent_rate)
1795 {
1796 	return AD4130_MCLK_FREQ_76_8KHZ;
1797 }
1798 
1799 static int ad4130_int_clk_is_enabled(struct clk_hw *hw)
1800 {
1801 	struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
1802 
1803 	return st->mclk_sel == AD4130_MCLK_76_8KHZ_OUT;
1804 }
1805 
1806 static int ad4130_int_clk_prepare(struct clk_hw *hw)
1807 {
1808 	struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
1809 	int ret;
1810 
1811 	ret = ad4130_set_mclk_sel(st, AD4130_MCLK_76_8KHZ_OUT);
1812 	if (ret)
1813 		return ret;
1814 
1815 	st->mclk_sel = AD4130_MCLK_76_8KHZ_OUT;
1816 
1817 	return 0;
1818 }
1819 
1820 static void ad4130_int_clk_unprepare(struct clk_hw *hw)
1821 {
1822 	struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
1823 	int ret;
1824 
1825 	ret = ad4130_set_mclk_sel(st, AD4130_MCLK_76_8KHZ);
1826 	if (ret)
1827 		return;
1828 
1829 	st->mclk_sel = AD4130_MCLK_76_8KHZ;
1830 }
1831 
1832 static const struct clk_ops ad4130_int_clk_ops = {
1833 	.recalc_rate = ad4130_int_clk_recalc_rate,
1834 	.is_enabled = ad4130_int_clk_is_enabled,
1835 	.prepare = ad4130_int_clk_prepare,
1836 	.unprepare = ad4130_int_clk_unprepare,
1837 };
1838 
1839 static int ad4130_setup_int_clk(struct ad4130_state *st)
1840 {
1841 	struct device *dev = &st->spi->dev;
1842 	struct device_node *of_node = dev_of_node(dev);
1843 	struct clk_init_data init = {};
1844 	const char *clk_name;
1845 	int ret;
1846 
1847 	if (st->int_pin_sel == AD4130_INT_PIN_CLK ||
1848 	    st->mclk_sel != AD4130_MCLK_76_8KHZ)
1849 		return 0;
1850 
1851 	if (!of_node)
1852 		return 0;
1853 
1854 	clk_name = of_node->name;
1855 	of_property_read_string(of_node, "clock-output-names", &clk_name);
1856 
1857 	init.name = clk_name;
1858 	init.ops = &ad4130_int_clk_ops;
1859 
1860 	st->int_clk_hw.init = &init;
1861 	ret = devm_clk_hw_register(dev, &st->int_clk_hw);
1862 	if (ret)
1863 		return ret;
1864 
1865 	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
1866 					   &st->int_clk_hw);
1867 }
1868 
1869 static int ad4130_setup(struct iio_dev *indio_dev)
1870 {
1871 	struct ad4130_state *st = iio_priv(indio_dev);
1872 	struct device *dev = &st->spi->dev;
1873 	unsigned int int_ref_val;
1874 	unsigned long rate = AD4130_MCLK_FREQ_76_8KHZ;
1875 	unsigned int val;
1876 	unsigned int i;
1877 	int ret;
1878 
1879 	if (st->mclk_sel == AD4130_MCLK_153_6KHZ_EXT)
1880 		rate = AD4130_MCLK_FREQ_153_6KHZ;
1881 
1882 	ret = clk_set_rate(st->mclk, rate);
1883 	if (ret)
1884 		return ret;
1885 
1886 	ret = clk_prepare_enable(st->mclk);
1887 	if (ret)
1888 		return ret;
1889 
1890 	ret = devm_add_action_or_reset(dev, ad4130_clk_disable_unprepare,
1891 				       st->mclk);
1892 	if (ret)
1893 		return ret;
1894 
1895 	if (st->int_ref_uv == AD4130_INT_REF_2_5V)
1896 		int_ref_val = AD4130_INT_REF_VAL_2_5V;
1897 	else
1898 		int_ref_val = AD4130_INT_REF_VAL_1_25V;
1899 
1900 	/* Switch to SPI 4-wire mode. */
1901 	val =  FIELD_PREP(AD4130_ADC_CONTROL_CSB_EN_MASK, 1);
1902 	val |= FIELD_PREP(AD4130_ADC_CONTROL_BIPOLAR_MASK, st->bipolar);
1903 	val |= FIELD_PREP(AD4130_ADC_CONTROL_INT_REF_EN_MASK, st->int_ref_en);
1904 	val |= FIELD_PREP(AD4130_ADC_CONTROL_MODE_MASK, AD4130_MODE_IDLE);
1905 	val |= FIELD_PREP(AD4130_ADC_CONTROL_MCLK_SEL_MASK, st->mclk_sel);
1906 	val |= FIELD_PREP(AD4130_ADC_CONTROL_INT_REF_VAL_MASK, int_ref_val);
1907 
1908 	ret = regmap_write(st->regmap, AD4130_ADC_CONTROL_REG, val);
1909 	if (ret)
1910 		return ret;
1911 
1912 	/*
1913 	 * Configure unused GPIOs for output. If configured, the interrupt
1914 	 * function of P2 takes priority over the GPIO out function.
1915 	 */
1916 	val = 0;
1917 	for (i = 0; i < AD4130_MAX_GPIOS; i++)
1918 		if (st->pins_fn[i + AD4130_AIN2_P1] == AD4130_PIN_FN_NONE)
1919 			val |= FIELD_PREP(AD4130_IO_CONTROL_GPIO_CTRL_MASK, BIT(i));
1920 
1921 	val |= FIELD_PREP(AD4130_IO_CONTROL_INT_PIN_SEL_MASK, st->int_pin_sel);
1922 
1923 	ret = regmap_write(st->regmap, AD4130_IO_CONTROL_REG, val);
1924 	if (ret)
1925 		return ret;
1926 
1927 	val = 0;
1928 	for (i = 0; i < st->num_vbias_pins; i++)
1929 		val |= BIT(st->vbias_pins[i]);
1930 
1931 	ret = regmap_write(st->regmap, AD4130_VBIAS_REG, val);
1932 	if (ret)
1933 		return ret;
1934 
1935 	ret = regmap_clear_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
1936 				AD4130_FIFO_CONTROL_HEADER_MASK);
1937 	if (ret)
1938 		return ret;
1939 
1940 	/* FIFO watermark interrupt starts out as enabled, disable it. */
1941 	ret = ad4130_set_watermark_interrupt_en(st, false);
1942 	if (ret)
1943 		return ret;
1944 
1945 	/* Setup channels. */
1946 	for (i = 0; i < indio_dev->num_channels; i++) {
1947 		struct ad4130_chan_info *chan_info = &st->chans_info[i];
1948 		struct iio_chan_spec *chan = &st->chans[i];
1949 		unsigned int val;
1950 
1951 		val = FIELD_PREP(AD4130_CHANNEL_AINP_MASK, chan->channel) |
1952 		      FIELD_PREP(AD4130_CHANNEL_AINM_MASK, chan->channel2) |
1953 		      FIELD_PREP(AD4130_CHANNEL_IOUT1_MASK, chan_info->iout0) |
1954 		      FIELD_PREP(AD4130_CHANNEL_IOUT2_MASK, chan_info->iout1);
1955 
1956 		ret = regmap_write(st->regmap, AD4130_CHANNEL_X_REG(i), val);
1957 		if (ret)
1958 			return ret;
1959 	}
1960 
1961 	return 0;
1962 }
1963 
1964 static int ad4130_soft_reset(struct ad4130_state *st)
1965 {
1966 	int ret;
1967 
1968 	ret = spi_write(st->spi, st->reset_buf, sizeof(st->reset_buf));
1969 	if (ret)
1970 		return ret;
1971 
1972 	fsleep(AD4130_RESET_SLEEP_US);
1973 
1974 	return 0;
1975 }
1976 
1977 static void ad4130_disable_regulators(void *data)
1978 {
1979 	struct ad4130_state *st = data;
1980 
1981 	regulator_bulk_disable(ARRAY_SIZE(st->regulators), st->regulators);
1982 }
1983 
1984 static int ad4130_probe(struct spi_device *spi)
1985 {
1986 	struct device *dev = &spi->dev;
1987 	struct iio_dev *indio_dev;
1988 	struct ad4130_state *st;
1989 	int ret;
1990 
1991 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
1992 	if (!indio_dev)
1993 		return -ENOMEM;
1994 
1995 	st = iio_priv(indio_dev);
1996 
1997 	memset(st->reset_buf, 0xff, sizeof(st->reset_buf));
1998 	init_completion(&st->completion);
1999 	mutex_init(&st->lock);
2000 	st->spi = spi;
2001 
2002 	/*
2003 	 * Xfer:   [ XFR1 ] [         XFR2         ]
2004 	 * Master:  0x7D N   ......................
2005 	 * Slave:   ......   DATA1 DATA2 ... DATAN
2006 	 */
2007 	st->fifo_tx_buf[0] = AD4130_COMMS_READ_MASK | AD4130_FIFO_DATA_REG;
2008 	st->fifo_xfer[0].tx_buf = st->fifo_tx_buf;
2009 	st->fifo_xfer[0].len = sizeof(st->fifo_tx_buf);
2010 	st->fifo_xfer[1].rx_buf = st->fifo_rx_buf;
2011 	spi_message_init_with_transfers(&st->fifo_msg, st->fifo_xfer,
2012 					ARRAY_SIZE(st->fifo_xfer));
2013 
2014 	indio_dev->name = AD4130_NAME;
2015 	indio_dev->modes = INDIO_DIRECT_MODE;
2016 	indio_dev->info = &ad4130_info;
2017 
2018 	st->regmap = devm_regmap_init(dev, NULL, st, &ad4130_regmap_config);
2019 	if (IS_ERR(st->regmap))
2020 		return PTR_ERR(st->regmap);
2021 
2022 	st->regulators[0].supply = "avdd";
2023 	st->regulators[1].supply = "iovdd";
2024 	st->regulators[2].supply = "refin1";
2025 	st->regulators[3].supply = "refin2";
2026 
2027 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(st->regulators),
2028 				      st->regulators);
2029 	if (ret)
2030 		return dev_err_probe(dev, ret, "Failed to get regulators\n");
2031 
2032 	ret = regulator_bulk_enable(ARRAY_SIZE(st->regulators), st->regulators);
2033 	if (ret)
2034 		return dev_err_probe(dev, ret, "Failed to enable regulators\n");
2035 
2036 	ret = devm_add_action_or_reset(dev, ad4130_disable_regulators, st);
2037 	if (ret)
2038 		return dev_err_probe(dev, ret,
2039 				     "Failed to add regulators disable action\n");
2040 
2041 	ret = ad4130_soft_reset(st);
2042 	if (ret)
2043 		return ret;
2044 
2045 	ret = ad4310_parse_fw(indio_dev);
2046 	if (ret)
2047 		return ret;
2048 
2049 	ret = ad4130_setup(indio_dev);
2050 	if (ret)
2051 		return ret;
2052 
2053 	ret = ad4130_setup_int_clk(st);
2054 	if (ret)
2055 		return ret;
2056 
2057 	ad4130_fill_scale_tbls(st);
2058 
2059 	st->gc.owner = THIS_MODULE;
2060 	st->gc.label = AD4130_NAME;
2061 	st->gc.base = -1;
2062 	st->gc.ngpio = AD4130_MAX_GPIOS;
2063 	st->gc.parent = dev;
2064 	st->gc.can_sleep = true;
2065 	st->gc.init_valid_mask = ad4130_gpio_init_valid_mask;
2066 	st->gc.get_direction = ad4130_gpio_get_direction;
2067 	st->gc.set_rv = ad4130_gpio_set;
2068 
2069 	ret = devm_gpiochip_add_data(dev, &st->gc, st);
2070 	if (ret)
2071 		return ret;
2072 
2073 	ret = devm_iio_kfifo_buffer_setup_ext(dev, indio_dev,
2074 					      &ad4130_buffer_ops,
2075 					      ad4130_fifo_attributes);
2076 	if (ret)
2077 		return ret;
2078 
2079 	ret = devm_request_threaded_irq(dev, spi->irq, NULL,
2080 					ad4130_irq_handler, IRQF_ONESHOT,
2081 					indio_dev->name, indio_dev);
2082 	if (ret)
2083 		return dev_err_probe(dev, ret, "Failed to request irq\n");
2084 
2085 	/*
2086 	 * When the chip enters FIFO mode, IRQ polarity is inverted.
2087 	 * When the chip exits FIFO mode, IRQ polarity returns to normal.
2088 	 * See datasheet pages: 65, FIFO Watermark Interrupt section,
2089 	 * and 71, Bit Descriptions for STATUS Register, RDYB.
2090 	 * Cache the normal and inverted IRQ triggers to set them when
2091 	 * entering and exiting FIFO mode.
2092 	 */
2093 	st->irq_trigger = irq_get_trigger_type(spi->irq);
2094 	if (st->irq_trigger & IRQF_TRIGGER_RISING)
2095 		st->inv_irq_trigger = IRQF_TRIGGER_FALLING;
2096 	else if (st->irq_trigger & IRQF_TRIGGER_FALLING)
2097 		st->inv_irq_trigger = IRQF_TRIGGER_RISING;
2098 	else
2099 		return dev_err_probe(dev, -EINVAL, "Invalid irq flags: %u\n",
2100 				     st->irq_trigger);
2101 
2102 	return devm_iio_device_register(dev, indio_dev);
2103 }
2104 
2105 static const struct of_device_id ad4130_of_match[] = {
2106 	{
2107 		.compatible = "adi,ad4130",
2108 	},
2109 	{ }
2110 };
2111 MODULE_DEVICE_TABLE(of, ad4130_of_match);
2112 
2113 static struct spi_driver ad4130_driver = {
2114 	.driver = {
2115 		.name = AD4130_NAME,
2116 		.of_match_table = ad4130_of_match,
2117 	},
2118 	.probe = ad4130_probe,
2119 };
2120 module_spi_driver(ad4130_driver);
2121 
2122 MODULE_AUTHOR("Cosmin Tanislav <cosmin.tanislav@analog.com>");
2123 MODULE_DESCRIPTION("Analog Devices AD4130 SPI driver");
2124 MODULE_LICENSE("GPL");
2125