1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Analog Devices Generic AXI ADC IP core
4  * Link: https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
5  *
6  * Copyright 2012-2020 Analog Devices Inc.
7  */
8 
9 #include <linux/bitfield.h>
10 #include <linux/cleanup.h>
11 #include <linux/clk.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/delay.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/platform_device.h>
19 #include <linux/property.h>
20 #include <linux/regmap.h>
21 #include <linux/slab.h>
22 
23 #include <linux/fpga/adi-axi-common.h>
24 
25 #include <linux/iio/backend.h>
26 #include <linux/iio/buffer-dmaengine.h>
27 #include <linux/iio/buffer.h>
28 #include <linux/iio/iio.h>
29 
30 #include "ad7606_bus_iface.h"
31 /*
32  * Register definitions:
33  *   https://wiki.analog.com/resources/fpga/docs/axi_adc_ip#register_map
34  */
35 
36 /* ADC controls */
37 
38 #define ADI_AXI_REG_RSTN			0x0040
39 #define   ADI_AXI_REG_RSTN_CE_N			BIT(2)
40 #define   ADI_AXI_REG_RSTN_MMCM_RSTN		BIT(1)
41 #define   ADI_AXI_REG_RSTN_RSTN			BIT(0)
42 
43 #define ADI_AXI_ADC_REG_CONFIG			0x000c
44 #define   ADI_AXI_ADC_REG_CONFIG_CMOS_OR_LVDS_N	BIT(7)
45 
46 #define ADI_AXI_ADC_REG_CTRL			0x0044
47 #define    ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK	BIT(1)
48 
49 #define ADI_AXI_ADC_REG_CNTRL_3			0x004c
50 #define   AXI_AD485X_CNTRL_3_OS_EN_MSK		BIT(2)
51 #define   AXI_AD485X_CNTRL_3_PACKET_FORMAT_MSK	GENMASK(1, 0)
52 #define   AXI_AD485X_PACKET_FORMAT_20BIT	0x0
53 #define   AXI_AD485X_PACKET_FORMAT_24BIT	0x1
54 #define   AXI_AD485X_PACKET_FORMAT_32BIT	0x2
55 
56 #define ADI_AXI_ADC_REG_DRP_STATUS		0x0074
57 #define   ADI_AXI_ADC_DRP_LOCKED		BIT(17)
58 
59 /* ADC Channel controls */
60 
61 #define ADI_AXI_REG_CHAN_CTRL(c)		(0x0400 + (c) * 0x40)
62 #define   ADI_AXI_REG_CHAN_CTRL_LB_OWR		BIT(11)
63 #define   ADI_AXI_REG_CHAN_CTRL_PN_SEL_OWR	BIT(10)
64 #define   ADI_AXI_REG_CHAN_CTRL_IQCOR_EN	BIT(9)
65 #define   ADI_AXI_REG_CHAN_CTRL_DCFILT_EN	BIT(8)
66 #define   ADI_AXI_REG_CHAN_CTRL_FMT_MASK	GENMASK(6, 4)
67 #define   ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT	BIT(6)
68 #define   ADI_AXI_REG_CHAN_CTRL_FMT_TYPE	BIT(5)
69 #define   ADI_AXI_REG_CHAN_CTRL_FMT_EN		BIT(4)
70 #define   ADI_AXI_REG_CHAN_CTRL_PN_TYPE_OWR	BIT(1)
71 #define   ADI_AXI_REG_CHAN_CTRL_ENABLE		BIT(0)
72 
73 #define ADI_AXI_ADC_REG_CHAN_STATUS(c)		(0x0404 + (c) * 0x40)
74 #define   ADI_AXI_ADC_CHAN_STAT_PN_MASK		GENMASK(2, 1)
75 /* out of sync */
76 #define   ADI_AXI_ADC_CHAN_STAT_PN_OOS		BIT(1)
77 /* spurious out of sync */
78 #define   ADI_AXI_ADC_CHAN_STAT_PN_ERR		BIT(2)
79 
80 #define ADI_AXI_ADC_REG_CHAN_CTRL_3(c)		(0x0418 + (c) * 0x40)
81 #define   ADI_AXI_ADC_CHAN_PN_SEL_MASK		GENMASK(19, 16)
82 
83 /* IO Delays */
84 #define ADI_AXI_ADC_REG_DELAY(l)		(0x0800 + (l) * 0x4)
85 #define   AXI_ADC_DELAY_CTRL_MASK		GENMASK(4, 0)
86 
87 #define ADI_AXI_REG_CONFIG_WR			0x0080
88 #define ADI_AXI_REG_CONFIG_RD			0x0084
89 #define ADI_AXI_REG_CONFIG_CTRL			0x008c
90 #define   ADI_AXI_REG_CONFIG_CTRL_READ		0x03
91 #define   ADI_AXI_REG_CONFIG_CTRL_WRITE		0x01
92 
93 #define ADI_AXI_ADC_MAX_IO_NUM_LANES		15
94 
95 #define ADI_AXI_REG_CHAN_CTRL_DEFAULTS		\
96 	(ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT |	\
97 	 ADI_AXI_REG_CHAN_CTRL_FMT_EN |		\
98 	 ADI_AXI_REG_CHAN_CTRL_ENABLE)
99 
100 #define ADI_AXI_REG_READ_BIT			0x8000
101 #define ADI_AXI_REG_ADDRESS_MASK		0xff00
102 #define ADI_AXI_REG_VALUE_MASK			0x00ff
103 
104 struct axi_adc_info {
105 	unsigned int version;
106 	const struct iio_backend_info *backend_info;
107 	bool has_child_nodes;
108 	const void *pdata;
109 	unsigned int pdata_sz;
110 };
111 
112 struct adi_axi_adc_state {
113 	const struct axi_adc_info *info;
114 	struct regmap *regmap;
115 	struct device *dev;
116 	/* lock to protect multiple accesses to the device registers */
117 	struct mutex lock;
118 };
119 
120 static int axi_adc_enable(struct iio_backend *back)
121 {
122 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
123 	unsigned int __val;
124 	int ret;
125 
126 	guard(mutex)(&st->lock);
127 	ret = regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
128 			      ADI_AXI_REG_RSTN_MMCM_RSTN);
129 	if (ret)
130 		return ret;
131 
132 	/*
133 	 * Make sure the DRP (Dynamic Reconfiguration Port) is locked. Not all
134 	 * designs really use it but if they don't we still get the lock bit
135 	 * set. So let's do it all the time so the code is generic.
136 	 */
137 	ret = regmap_read_poll_timeout(st->regmap, ADI_AXI_ADC_REG_DRP_STATUS,
138 				       __val, __val & ADI_AXI_ADC_DRP_LOCKED,
139 				       100, 1000);
140 	if (ret)
141 		return ret;
142 
143 	return regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
144 			       ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
145 }
146 
147 static void axi_adc_disable(struct iio_backend *back)
148 {
149 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
150 
151 	guard(mutex)(&st->lock);
152 	regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
153 }
154 
155 static int axi_adc_data_format_set(struct iio_backend *back, unsigned int chan,
156 				   const struct iio_backend_data_fmt *data)
157 {
158 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
159 	u32 val;
160 
161 	if (!data->enable)
162 		return regmap_clear_bits(st->regmap,
163 					 ADI_AXI_REG_CHAN_CTRL(chan),
164 					 ADI_AXI_REG_CHAN_CTRL_FMT_EN);
165 
166 	val = FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_EN, true);
167 	if (data->sign_extend)
168 		val |= FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT, true);
169 	if (data->type == IIO_BACKEND_OFFSET_BINARY)
170 		val |= FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_TYPE, true);
171 
172 	return regmap_update_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
173 				  ADI_AXI_REG_CHAN_CTRL_FMT_MASK, val);
174 }
175 
176 static int axi_adc_data_sample_trigger(struct iio_backend *back,
177 				       enum iio_backend_sample_trigger trigger)
178 {
179 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
180 
181 	switch (trigger) {
182 	case IIO_BACKEND_SAMPLE_TRIGGER_EDGE_RISING:
183 		return regmap_clear_bits(st->regmap, ADI_AXI_ADC_REG_CTRL,
184 					 ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK);
185 	case IIO_BACKEND_SAMPLE_TRIGGER_EDGE_FALLING:
186 		return regmap_set_bits(st->regmap, ADI_AXI_ADC_REG_CTRL,
187 				       ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK);
188 	default:
189 		return -EINVAL;
190 	}
191 }
192 
193 static int axi_adc_iodelays_set(struct iio_backend *back, unsigned int lane,
194 				unsigned int tap)
195 {
196 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
197 	int ret;
198 	u32 val;
199 
200 	if (tap > FIELD_MAX(AXI_ADC_DELAY_CTRL_MASK))
201 		return -EINVAL;
202 	if (lane > ADI_AXI_ADC_MAX_IO_NUM_LANES)
203 		return -EINVAL;
204 
205 	guard(mutex)(&st->lock);
206 	ret = regmap_write(st->regmap, ADI_AXI_ADC_REG_DELAY(lane), tap);
207 	if (ret)
208 		return ret;
209 	/*
210 	 * If readback is ~0, that means there are issues with the
211 	 * delay_clk.
212 	 */
213 	ret = regmap_read(st->regmap, ADI_AXI_ADC_REG_DELAY(lane), &val);
214 	if (ret)
215 		return ret;
216 	if (val == U32_MAX)
217 		return -EIO;
218 
219 	return 0;
220 }
221 
222 static int axi_adc_test_pattern_set(struct iio_backend *back,
223 				    unsigned int chan,
224 				    enum iio_backend_test_pattern pattern)
225 {
226 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
227 
228 	switch (pattern) {
229 	case IIO_BACKEND_NO_TEST_PATTERN:
230 		/* nothing to do */
231 		return 0;
232 	case IIO_BACKEND_ADI_PRBS_9A:
233 		return regmap_update_bits(st->regmap, ADI_AXI_ADC_REG_CHAN_CTRL_3(chan),
234 					  ADI_AXI_ADC_CHAN_PN_SEL_MASK,
235 					  FIELD_PREP(ADI_AXI_ADC_CHAN_PN_SEL_MASK, 0));
236 	case IIO_BACKEND_ADI_PRBS_23A:
237 		return regmap_update_bits(st->regmap, ADI_AXI_ADC_REG_CHAN_CTRL_3(chan),
238 					  ADI_AXI_ADC_CHAN_PN_SEL_MASK,
239 					  FIELD_PREP(ADI_AXI_ADC_CHAN_PN_SEL_MASK, 1));
240 	default:
241 		return -EINVAL;
242 	}
243 }
244 
245 static int axi_adc_read_chan_status(struct adi_axi_adc_state *st, unsigned int chan,
246 				    unsigned int *status)
247 {
248 	int ret;
249 
250 	guard(mutex)(&st->lock);
251 	/* reset test bits by setting them */
252 	ret = regmap_write(st->regmap, ADI_AXI_ADC_REG_CHAN_STATUS(chan),
253 			   ADI_AXI_ADC_CHAN_STAT_PN_MASK);
254 	if (ret)
255 		return ret;
256 
257 	/* let's give enough time to validate or erroring the incoming pattern */
258 	fsleep(1000);
259 
260 	return regmap_read(st->regmap, ADI_AXI_ADC_REG_CHAN_STATUS(chan),
261 			   status);
262 }
263 
264 static int axi_adc_chan_status(struct iio_backend *back, unsigned int chan,
265 			       bool *error)
266 {
267 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
268 	u32 val;
269 	int ret;
270 
271 	ret = axi_adc_read_chan_status(st, chan, &val);
272 	if (ret)
273 		return ret;
274 
275 	if (ADI_AXI_ADC_CHAN_STAT_PN_MASK & val)
276 		*error = true;
277 	else
278 		*error = false;
279 
280 	return 0;
281 }
282 
283 static int axi_adc_debugfs_print_chan_status(struct iio_backend *back,
284 					     unsigned int chan, char *buf,
285 					     size_t len)
286 {
287 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
288 	u32 val;
289 	int ret;
290 
291 	ret = axi_adc_read_chan_status(st, chan, &val);
292 	if (ret)
293 		return ret;
294 
295 	/*
296 	 * PN_ERR is cleared in case out of sync is set. Hence, no point in
297 	 * checking both bits.
298 	 */
299 	if (val & ADI_AXI_ADC_CHAN_STAT_PN_OOS)
300 		return scnprintf(buf, len, "CH%u: Out of Sync.\n", chan);
301 	if (val & ADI_AXI_ADC_CHAN_STAT_PN_ERR)
302 		return scnprintf(buf, len, "CH%u: Spurious Out of Sync.\n", chan);
303 
304 	return scnprintf(buf, len, "CH%u: OK.\n", chan);
305 }
306 
307 static int axi_adc_chan_enable(struct iio_backend *back, unsigned int chan)
308 {
309 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
310 
311 	return regmap_set_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
312 			       ADI_AXI_REG_CHAN_CTRL_ENABLE);
313 }
314 
315 static int axi_adc_chan_disable(struct iio_backend *back, unsigned int chan)
316 {
317 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
318 
319 	return regmap_clear_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
320 				 ADI_AXI_REG_CHAN_CTRL_ENABLE);
321 }
322 
323 static int axi_adc_interface_type_get(struct iio_backend *back,
324 				      enum iio_backend_interface_type *type)
325 {
326 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
327 	unsigned int val;
328 	int ret;
329 
330 	ret = regmap_read(st->regmap, ADI_AXI_ADC_REG_CONFIG, &val);
331 	if (ret)
332 		return ret;
333 
334 	if (val & ADI_AXI_ADC_REG_CONFIG_CMOS_OR_LVDS_N)
335 		*type = IIO_BACKEND_INTERFACE_SERIAL_CMOS;
336 	else
337 		*type = IIO_BACKEND_INTERFACE_SERIAL_LVDS;
338 
339 	return 0;
340 }
341 
342 static int axi_adc_ad485x_data_size_set(struct iio_backend *back,
343 					unsigned int size)
344 {
345 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
346 	unsigned int val;
347 
348 	switch (size) {
349 	/*
350 	 * There are two different variants of the AXI AXI_AD485X IP block, a
351 	 * 16-bit and a 20-bit variant.
352 	 * The 0x0 value (AXI_AD485X_PACKET_FORMAT_20BIT) is corresponding also
353 	 * to the 16-bit variant of the IP block.
354 	 */
355 	case 16:
356 	case 20:
357 		val = AXI_AD485X_PACKET_FORMAT_20BIT;
358 		break;
359 	case 24:
360 		val = AXI_AD485X_PACKET_FORMAT_24BIT;
361 		break;
362 	/*
363 	 * The 0x2 (AXI_AD485X_PACKET_FORMAT_32BIT) corresponds only to the
364 	 * 20-bit variant of the IP block. Setting this value properly is
365 	 * ensured by the upper layers of the drivers calling the axi-adc
366 	 * functions.
367 	 * Also, for 16-bit IP block, the 0x2 (AXI_AD485X_PACKET_FORMAT_32BIT)
368 	 * value is handled as maximum size available which is 24-bit for this
369 	 * configuration.
370 	 */
371 	case 32:
372 		val = AXI_AD485X_PACKET_FORMAT_32BIT;
373 		break;
374 	default:
375 		return -EINVAL;
376 	}
377 
378 	return regmap_update_bits(st->regmap, ADI_AXI_ADC_REG_CNTRL_3,
379 				  AXI_AD485X_CNTRL_3_PACKET_FORMAT_MSK,
380 				  FIELD_PREP(AXI_AD485X_CNTRL_3_PACKET_FORMAT_MSK, val));
381 }
382 
383 static int axi_adc_ad485x_oversampling_ratio_set(struct iio_backend *back,
384 					  unsigned int ratio)
385 {
386 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
387 
388 	/* The current state of the function enables or disables the
389 	 * oversampling in REG_CNTRL_3 register. A ratio equal to 1 implies no
390 	 * oversampling, while a value greater than 1 implies oversampling being
391 	 * enabled.
392 	 */
393 	switch (ratio) {
394 	case 0:
395 		return -EINVAL;
396 	case 1:
397 		return regmap_clear_bits(st->regmap, ADI_AXI_ADC_REG_CNTRL_3,
398 					 AXI_AD485X_CNTRL_3_OS_EN_MSK);
399 	default:
400 		return regmap_set_bits(st->regmap, ADI_AXI_ADC_REG_CNTRL_3,
401 				       AXI_AD485X_CNTRL_3_OS_EN_MSK);
402 	}
403 }
404 
405 static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
406 						 struct iio_dev *indio_dev)
407 {
408 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
409 	const char *dma_name;
410 
411 	if (device_property_read_string(st->dev, "dma-names", &dma_name))
412 		dma_name = "rx";
413 
414 	return iio_dmaengine_buffer_setup(st->dev, indio_dev, dma_name);
415 }
416 
417 static int axi_adc_raw_write(struct iio_backend *back, u32 val)
418 {
419 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
420 
421 	regmap_write(st->regmap, ADI_AXI_REG_CONFIG_WR, val);
422 	regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL,
423 		     ADI_AXI_REG_CONFIG_CTRL_WRITE);
424 	fsleep(100);
425 	regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL, 0x00);
426 	fsleep(100);
427 
428 	return 0;
429 }
430 
431 static int axi_adc_raw_read(struct iio_backend *back, u32 *val)
432 {
433 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
434 
435 	regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL,
436 		     ADI_AXI_REG_CONFIG_CTRL_READ);
437 	fsleep(100);
438 	regmap_read(st->regmap, ADI_AXI_REG_CONFIG_RD, val);
439 	regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL, 0x00);
440 	fsleep(100);
441 
442 	return 0;
443 }
444 
445 static int ad7606_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val)
446 {
447 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
448 	int addr;
449 
450 	guard(mutex)(&st->lock);
451 
452 	/*
453 	 * The address is written on the highest weight byte, and the MSB set
454 	 * at 1 indicates a read operation.
455 	 */
456 	addr = FIELD_PREP(ADI_AXI_REG_ADDRESS_MASK, reg) | ADI_AXI_REG_READ_BIT;
457 	axi_adc_raw_write(back, addr);
458 	axi_adc_raw_read(back, val);
459 
460 	/* Write 0x0 on the bus to get back to ADC mode */
461 	axi_adc_raw_write(back, 0);
462 
463 	return 0;
464 }
465 
466 static int ad7606_bus_reg_write(struct iio_backend *back, u32 reg, u32 val)
467 {
468 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
469 	u32 buf;
470 
471 	guard(mutex)(&st->lock);
472 
473 	/* Write any register to switch to register mode */
474 	axi_adc_raw_write(back, 0xaf00);
475 
476 	buf = FIELD_PREP(ADI_AXI_REG_ADDRESS_MASK, reg) |
477 	      FIELD_PREP(ADI_AXI_REG_VALUE_MASK, val);
478 	axi_adc_raw_write(back, buf);
479 
480 	/* Write 0x0 on the bus to get back to ADC mode */
481 	axi_adc_raw_write(back, 0);
482 
483 	return 0;
484 }
485 
486 static void axi_adc_free_buffer(struct iio_backend *back,
487 				struct iio_buffer *buffer)
488 {
489 	iio_dmaengine_buffer_teardown(buffer);
490 }
491 
492 static int axi_adc_reg_access(struct iio_backend *back, unsigned int reg,
493 			      unsigned int writeval, unsigned int *readval)
494 {
495 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
496 
497 	if (readval)
498 		return regmap_read(st->regmap, reg, readval);
499 
500 	return regmap_write(st->regmap, reg, writeval);
501 }
502 
503 static const struct regmap_config axi_adc_regmap_config = {
504 	.val_bits = 32,
505 	.reg_bits = 32,
506 	.reg_stride = 4,
507 };
508 
509 static void axi_adc_child_remove(void *data)
510 {
511 	platform_device_unregister(data);
512 }
513 
514 static int axi_adc_create_platform_device(struct adi_axi_adc_state *st,
515 					  struct fwnode_handle *child)
516 {
517 	struct platform_device_info pi = {
518 	    .parent = st->dev,
519 	    .name = fwnode_get_name(child),
520 	    .id = PLATFORM_DEVID_AUTO,
521 	    .fwnode = child,
522 	    .data = st->info->pdata,
523 	    .size_data = st->info->pdata_sz,
524 	};
525 	struct platform_device *pdev;
526 	int ret;
527 
528 	pdev = platform_device_register_full(&pi);
529 	if (IS_ERR(pdev))
530 		return PTR_ERR(pdev);
531 
532 	ret = devm_add_action_or_reset(st->dev, axi_adc_child_remove, pdev);
533 	if (ret)
534 		return ret;
535 
536 	return 0;
537 }
538 
539 static const struct iio_backend_ops adi_axi_adc_ops = {
540 	.enable = axi_adc_enable,
541 	.disable = axi_adc_disable,
542 	.data_format_set = axi_adc_data_format_set,
543 	.chan_enable = axi_adc_chan_enable,
544 	.chan_disable = axi_adc_chan_disable,
545 	.request_buffer = axi_adc_request_buffer,
546 	.free_buffer = axi_adc_free_buffer,
547 	.data_sample_trigger = axi_adc_data_sample_trigger,
548 	.iodelay_set = axi_adc_iodelays_set,
549 	.test_pattern_set = axi_adc_test_pattern_set,
550 	.chan_status = axi_adc_chan_status,
551 	.interface_type_get = axi_adc_interface_type_get,
552 	.debugfs_reg_access = iio_backend_debugfs_ptr(axi_adc_reg_access),
553 	.debugfs_print_chan_status = iio_backend_debugfs_ptr(axi_adc_debugfs_print_chan_status),
554 };
555 
556 static const struct iio_backend_info adi_axi_adc_generic = {
557 	.name = "axi-adc",
558 	.ops = &adi_axi_adc_ops,
559 };
560 
561 static const struct iio_backend_ops adi_ad485x_ops = {
562 	.enable = axi_adc_enable,
563 	.disable = axi_adc_disable,
564 	.data_format_set = axi_adc_data_format_set,
565 	.chan_enable = axi_adc_chan_enable,
566 	.chan_disable = axi_adc_chan_disable,
567 	.request_buffer = axi_adc_request_buffer,
568 	.free_buffer = axi_adc_free_buffer,
569 	.data_sample_trigger = axi_adc_data_sample_trigger,
570 	.iodelay_set = axi_adc_iodelays_set,
571 	.chan_status = axi_adc_chan_status,
572 	.interface_type_get = axi_adc_interface_type_get,
573 	.data_size_set = axi_adc_ad485x_data_size_set,
574 	.oversampling_ratio_set = axi_adc_ad485x_oversampling_ratio_set,
575 	.debugfs_reg_access = iio_backend_debugfs_ptr(axi_adc_reg_access),
576 	.debugfs_print_chan_status =
577 		iio_backend_debugfs_ptr(axi_adc_debugfs_print_chan_status),
578 };
579 
580 static const struct iio_backend_info axi_ad485x = {
581 	.name = "axi-ad485x",
582 	.ops = &adi_ad485x_ops,
583 };
584 
585 static int adi_axi_adc_probe(struct platform_device *pdev)
586 {
587 	struct adi_axi_adc_state *st;
588 	void __iomem *base;
589 	unsigned int ver;
590 	struct clk *clk;
591 	int ret;
592 
593 	st = devm_kzalloc(&pdev->dev, sizeof(*st), GFP_KERNEL);
594 	if (!st)
595 		return -ENOMEM;
596 
597 	base = devm_platform_ioremap_resource(pdev, 0);
598 	if (IS_ERR(base))
599 		return PTR_ERR(base);
600 
601 	st->dev = &pdev->dev;
602 	st->regmap = devm_regmap_init_mmio(&pdev->dev, base,
603 					   &axi_adc_regmap_config);
604 	if (IS_ERR(st->regmap))
605 		return dev_err_probe(&pdev->dev, PTR_ERR(st->regmap),
606 				     "failed to init register map\n");
607 
608 	st->info = device_get_match_data(&pdev->dev);
609 	if (!st->info)
610 		return -ENODEV;
611 
612 	clk = devm_clk_get_enabled(&pdev->dev, NULL);
613 	if (IS_ERR(clk))
614 		return dev_err_probe(&pdev->dev, PTR_ERR(clk),
615 				     "failed to get clock\n");
616 
617 	/*
618 	 * Force disable the core. Up to the frontend to enable us. And we can
619 	 * still read/write registers...
620 	 */
621 	ret = regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
622 	if (ret)
623 		return ret;
624 
625 	ret = regmap_read(st->regmap, ADI_AXI_REG_VERSION, &ver);
626 	if (ret)
627 		return ret;
628 
629 	if (ADI_AXI_PCORE_VER_MAJOR(ver) !=
630 	    ADI_AXI_PCORE_VER_MAJOR(st->info->version)) {
631 		dev_err(&pdev->dev,
632 			"Major version mismatch. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
633 			ADI_AXI_PCORE_VER_MAJOR(st->info->version),
634 			ADI_AXI_PCORE_VER_MINOR(st->info->version),
635 			ADI_AXI_PCORE_VER_PATCH(st->info->version),
636 			ADI_AXI_PCORE_VER_MAJOR(ver),
637 			ADI_AXI_PCORE_VER_MINOR(ver),
638 			ADI_AXI_PCORE_VER_PATCH(ver));
639 		return -ENODEV;
640 	}
641 
642 	ret = devm_iio_backend_register(&pdev->dev, st->info->backend_info, st);
643 	if (ret)
644 		return dev_err_probe(&pdev->dev, ret,
645 				     "failed to register iio backend\n");
646 
647 	device_for_each_child_node_scoped(&pdev->dev, child) {
648 		int val;
649 
650 		if (!st->info->has_child_nodes)
651 			return dev_err_probe(&pdev->dev, -EINVAL,
652 					     "invalid fdt axi-dac compatible.");
653 
654 		/* Processing only reg 0 node */
655 		ret = fwnode_property_read_u32(child, "reg", &val);
656 		if (ret)
657 			return dev_err_probe(&pdev->dev, ret,
658 					     "invalid reg property.");
659 		if (val != 0)
660 			return dev_err_probe(&pdev->dev, -EINVAL,
661 					     "invalid node address.");
662 
663 		ret = axi_adc_create_platform_device(st, child);
664 		if (ret)
665 			return dev_err_probe(&pdev->dev, -EINVAL,
666 					     "cannot create device.");
667 	}
668 
669 	dev_info(&pdev->dev, "AXI ADC IP core (%d.%.2d.%c) probed\n",
670 		 ADI_AXI_PCORE_VER_MAJOR(ver),
671 		 ADI_AXI_PCORE_VER_MINOR(ver),
672 		 ADI_AXI_PCORE_VER_PATCH(ver));
673 
674 	return 0;
675 }
676 
677 static const struct axi_adc_info adc_generic = {
678 	.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
679 	.backend_info = &adi_axi_adc_generic,
680 };
681 
682 static const struct axi_adc_info adi_axi_ad485x = {
683 	.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
684 	.backend_info = &axi_ad485x,
685 };
686 
687 static const struct ad7606_platform_data ad7606_pdata = {
688 	.bus_reg_read = ad7606_bus_reg_read,
689 	.bus_reg_write = ad7606_bus_reg_write,
690 };
691 
692 static const struct axi_adc_info adc_ad7606 = {
693 	.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
694 	.backend_info = &adi_axi_adc_generic,
695 	.pdata = &ad7606_pdata,
696 	.pdata_sz = sizeof(ad7606_pdata),
697 	.has_child_nodes = true,
698 };
699 
700 /* Match table for of_platform binding */
701 static const struct of_device_id adi_axi_adc_of_match[] = {
702 	{ .compatible = "adi,axi-adc-10.0.a", .data = &adc_generic },
703 	{ .compatible = "adi,axi-ad485x", .data = &adi_axi_ad485x },
704 	{ .compatible = "adi,axi-ad7606x", .data = &adc_ad7606 },
705 	{ }
706 };
707 MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);
708 
709 static struct platform_driver adi_axi_adc_driver = {
710 	.driver = {
711 		.name = KBUILD_MODNAME,
712 		.of_match_table = adi_axi_adc_of_match,
713 	},
714 	.probe = adi_axi_adc_probe,
715 };
716 module_platform_driver(adi_axi_adc_driver);
717 
718 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
719 MODULE_DESCRIPTION("Analog Devices Generic AXI ADC IP core driver");
720 MODULE_LICENSE("GPL v2");
721 MODULE_IMPORT_NS("IIO_DMAENGINE_BUFFER");
722 MODULE_IMPORT_NS("IIO_BACKEND");
723