xref: /linux/drivers/iio/dac/adi-axi-dac.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Analog Devices Generic AXI DAC IP core
4  * Link: https://wiki.analog.com/resources/fpga/docs/axi_dac_ip
5  *
6  * Copyright 2016-2024 Analog Devices Inc.
7  */
8 #include <linux/bitfield.h>
9 #include <linux/bits.h>
10 #include <linux/cleanup.h>
11 #include <linux/clk.h>
12 #include <linux/device.h>
13 #include <linux/err.h>
14 #include <linux/limits.h>
15 #include <linux/kstrtox.h>
16 #include <linux/math.h>
17 #include <linux/math64.h>
18 #include <linux/module.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/mutex.h>
21 #include <linux/platform_device.h>
22 #include <linux/property.h>
23 #include <linux/regmap.h>
24 #include <linux/units.h>
25 
26 #include <linux/fpga/adi-axi-common.h>
27 #include <linux/iio/backend.h>
28 #include <linux/iio/buffer-dmaengine.h>
29 #include <linux/iio/buffer.h>
30 #include <linux/iio/iio.h>
31 
32 #include "ad3552r-hs.h"
33 
34 /*
35  * Register definitions:
36  *   https://wiki.analog.com/resources/fpga/docs/axi_dac_ip#register_map
37  */
38 
39 /* Base controls */
40 #define AXI_DAC_CONFIG_REG			0x0c
41 #define   AXI_DAC_CONFIG_DDS_DISABLE		BIT(6)
42 
43  /* DAC controls */
44 #define AXI_DAC_RSTN_REG			0x0040
45 #define   AXI_DAC_RSTN_CE_N			BIT(2)
46 #define   AXI_DAC_RSTN_MMCM_RSTN		BIT(1)
47 #define   AXI_DAC_RSTN_RSTN			BIT(0)
48 #define AXI_DAC_CNTRL_1_REG			0x0044
49 #define   AXI_DAC_CNTRL_1_SYNC			BIT(0)
50 #define AXI_DAC_CNTRL_2_REG			0x0048
51 #define   AXI_DAC_CNTRL_2_SDR_DDR_N		BIT(16)
52 #define   AXI_DAC_CNTRL_2_SYMB_8B		BIT(14)
53 #define   ADI_DAC_CNTRL_2_R1_MODE		BIT(5)
54 #define   AXI_DAC_CNTRL_2_UNSIGNED_DATA		BIT(4)
55 #define AXI_DAC_STATUS_1_REG			0x0054
56 #define AXI_DAC_STATUS_2_REG			0x0058
57 #define AXI_DAC_DRP_STATUS_REG			0x0074
58 #define   AXI_DAC_DRP_STATUS_DRP_LOCKED		BIT(17)
59 #define AXI_DAC_CUSTOM_RD_REG			0x0080
60 #define AXI_DAC_CUSTOM_WR_REG			0x0084
61 #define   AXI_DAC_CUSTOM_WR_DATA_8		GENMASK(23, 16)
62 #define   AXI_DAC_CUSTOM_WR_DATA_16		GENMASK(23, 8)
63 #define AXI_DAC_UI_STATUS_REG			0x0088
64 #define   AXI_DAC_UI_STATUS_IF_BUSY		BIT(4)
65 #define AXI_DAC_CUSTOM_CTRL_REG			0x008C
66 #define   AXI_DAC_CUSTOM_CTRL_ADDRESS		GENMASK(31, 24)
67 #define   AXI_DAC_CUSTOM_CTRL_SYNCED_TRANSFER	BIT(2)
68 #define   AXI_DAC_CUSTOM_CTRL_STREAM		BIT(1)
69 #define   AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA	BIT(0)
70 
71 #define AXI_DAC_CUSTOM_CTRL_STREAM_ENABLE	(AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA | \
72 						 AXI_DAC_CUSTOM_CTRL_STREAM)
73 
74 /* DAC Channel controls */
75 #define AXI_DAC_CHAN_CNTRL_1_REG(c)		(0x0400 + (c) * 0x40)
76 #define AXI_DAC_CHAN_CNTRL_3_REG(c)		(0x0408 + (c) * 0x40)
77 #define   AXI_DAC_CHAN_CNTRL_3_SCALE_SIGN	BIT(15)
78 #define   AXI_DAC_CHAN_CNTRL_3_SCALE_INT	BIT(14)
79 #define   AXI_DAC_CHAN_CNTRL_3_SCALE		GENMASK(14, 0)
80 #define AXI_DAC_CHAN_CNTRL_2_REG(c)		(0x0404 + (c) * 0x40)
81 #define   AXI_DAC_CHAN_CNTRL_2_PHASE		GENMASK(31, 16)
82 #define   AXI_DAC_CHAN_CNTRL_2_FREQUENCY	GENMASK(15, 0)
83 #define AXI_DAC_CHAN_CNTRL_4_REG(c)		(0x040c + (c) * 0x40)
84 #define AXI_DAC_CHAN_CNTRL_7_REG(c)		(0x0418 + (c) * 0x40)
85 #define   AXI_DAC_CHAN_CNTRL_7_DATA_SEL		GENMASK(3, 0)
86 
87 #define AXI_DAC_RD_ADDR(x)			(BIT(7) | (x))
88 
89 /* 360 degrees in rad */
90 #define AXI_DAC_2_PI_MEGA			6283190
91 
92 enum {
93 	AXI_DAC_DATA_INTERNAL_TONE,
94 	AXI_DAC_DATA_DMA = 2,
95 	AXI_DAC_DATA_INTERNAL_RAMP_16BIT = 11,
96 };
97 
98 struct axi_dac_info {
99 	unsigned int version;
100 	const struct iio_backend_info *backend_info;
101 	bool has_dac_clk;
102 	bool has_child_nodes;
103 };
104 
105 struct axi_dac_state {
106 	struct regmap *regmap;
107 	struct device *dev;
108 	/*
109 	 * lock to protect multiple accesses to the device registers and global
110 	 * data/variables.
111 	 */
112 	struct mutex lock;
113 	const struct axi_dac_info *info;
114 	u64 dac_clk;
115 	u32 reg_config;
116 	bool int_tone;
117 	int dac_clk_rate;
118 };
119 
120 static int axi_dac_enable(struct iio_backend *back)
121 {
122 	struct axi_dac_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, AXI_DAC_RSTN_REG,
128 			      AXI_DAC_RSTN_MMCM_RSTN);
129 	if (ret)
130 		return ret;
131 	/*
132 	 * Make sure the DRP (Dynamic Reconfiguration Port) is locked. Not all
133 	 * designs really use it but if they don't we still get the lock bit
134 	 * set. So let's do it all the time so the code is generic.
135 	 */
136 	ret = regmap_read_poll_timeout(st->regmap, AXI_DAC_DRP_STATUS_REG,
137 				       __val,
138 				       __val & AXI_DAC_DRP_STATUS_DRP_LOCKED,
139 				       100, 1000);
140 	if (ret)
141 		return ret;
142 
143 	return regmap_set_bits(st->regmap, AXI_DAC_RSTN_REG,
144 			       AXI_DAC_RSTN_RSTN | AXI_DAC_RSTN_MMCM_RSTN);
145 }
146 
147 static void axi_dac_disable(struct iio_backend *back)
148 {
149 	struct axi_dac_state *st = iio_backend_get_priv(back);
150 
151 	guard(mutex)(&st->lock);
152 	regmap_write(st->regmap, AXI_DAC_RSTN_REG, 0);
153 }
154 
155 static struct iio_buffer *axi_dac_request_buffer(struct iio_backend *back,
156 						 struct iio_dev *indio_dev)
157 {
158 	struct axi_dac_state *st = iio_backend_get_priv(back);
159 	const char *dma_name;
160 
161 	if (device_property_read_string(st->dev, "dma-names", &dma_name))
162 		dma_name = "tx";
163 
164 	return iio_dmaengine_buffer_setup_ext(st->dev, indio_dev, dma_name,
165 					      IIO_BUFFER_DIRECTION_OUT);
166 }
167 
168 static void axi_dac_free_buffer(struct iio_backend *back,
169 				struct iio_buffer *buffer)
170 {
171 	iio_dmaengine_buffer_free(buffer);
172 }
173 
174 enum {
175 	AXI_DAC_FREQ_TONE_1,
176 	AXI_DAC_FREQ_TONE_2,
177 	AXI_DAC_SCALE_TONE_1,
178 	AXI_DAC_SCALE_TONE_2,
179 	AXI_DAC_PHASE_TONE_1,
180 	AXI_DAC_PHASE_TONE_2,
181 };
182 
183 static int __axi_dac_frequency_get(struct axi_dac_state *st, unsigned int chan,
184 				   unsigned int tone_2, unsigned int *freq)
185 {
186 	u32 reg, raw;
187 	int ret;
188 
189 	if (!st->dac_clk) {
190 		dev_err(st->dev, "Sampling rate is 0...\n");
191 		return -EINVAL;
192 	}
193 
194 	if (tone_2)
195 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan);
196 	else
197 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan);
198 
199 	ret = regmap_read(st->regmap, reg, &raw);
200 	if (ret)
201 		return ret;
202 
203 	raw = FIELD_GET(AXI_DAC_CHAN_CNTRL_2_FREQUENCY, raw);
204 	*freq = DIV_ROUND_CLOSEST_ULL(raw * st->dac_clk, BIT(16));
205 
206 	return 0;
207 }
208 
209 static int axi_dac_frequency_get(struct axi_dac_state *st,
210 				 const struct iio_chan_spec *chan, char *buf,
211 				 unsigned int tone_2)
212 {
213 	unsigned int freq;
214 	int ret;
215 
216 	scoped_guard(mutex, &st->lock) {
217 		ret = __axi_dac_frequency_get(st, chan->channel, tone_2, &freq);
218 		if (ret)
219 			return ret;
220 	}
221 
222 	return sysfs_emit(buf, "%u\n", freq);
223 }
224 
225 static int axi_dac_scale_get(struct axi_dac_state *st,
226 			     const struct iio_chan_spec *chan, char *buf,
227 			     unsigned int tone_2)
228 {
229 	unsigned int scale, sign;
230 	int ret, vals[2];
231 	u32 reg, raw;
232 
233 	if (tone_2)
234 		reg = AXI_DAC_CHAN_CNTRL_3_REG(chan->channel);
235 	else
236 		reg = AXI_DAC_CHAN_CNTRL_1_REG(chan->channel);
237 
238 	ret = regmap_read(st->regmap, reg, &raw);
239 	if (ret)
240 		return ret;
241 
242 	sign = FIELD_GET(AXI_DAC_CHAN_CNTRL_3_SCALE_SIGN, raw);
243 	raw = FIELD_GET(AXI_DAC_CHAN_CNTRL_3_SCALE, raw);
244 	scale = DIV_ROUND_CLOSEST_ULL((u64)raw * MEGA,
245 				      AXI_DAC_CHAN_CNTRL_3_SCALE_INT);
246 
247 	vals[0] = scale / MEGA;
248 	vals[1] = scale % MEGA;
249 
250 	if (sign) {
251 		vals[0] *= -1;
252 		if (!vals[0])
253 			vals[1] *= -1;
254 	}
255 
256 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, ARRAY_SIZE(vals),
257 				vals);
258 }
259 
260 static int axi_dac_phase_get(struct axi_dac_state *st,
261 			     const struct iio_chan_spec *chan, char *buf,
262 			     unsigned int tone_2)
263 {
264 	u32 reg, raw, phase;
265 	int ret, vals[2];
266 
267 	if (tone_2)
268 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan->channel);
269 	else
270 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan->channel);
271 
272 	ret = regmap_read(st->regmap, reg, &raw);
273 	if (ret)
274 		return ret;
275 
276 	raw = FIELD_GET(AXI_DAC_CHAN_CNTRL_2_PHASE, raw);
277 	phase = DIV_ROUND_CLOSEST_ULL((u64)raw * AXI_DAC_2_PI_MEGA, U16_MAX);
278 
279 	vals[0] = phase / MEGA;
280 	vals[1] = phase % MEGA;
281 
282 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, ARRAY_SIZE(vals),
283 				vals);
284 }
285 
286 static int __axi_dac_frequency_set(struct axi_dac_state *st, unsigned int chan,
287 				   u64 sample_rate, unsigned int freq,
288 				   unsigned int tone_2)
289 {
290 	u32 reg;
291 	u16 raw;
292 	int ret;
293 
294 	if (!sample_rate || freq > sample_rate / 2) {
295 		dev_err(st->dev, "Invalid frequency(%u) dac_clk(%llu)\n",
296 			freq, sample_rate);
297 		return -EINVAL;
298 	}
299 
300 	if (tone_2)
301 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan);
302 	else
303 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan);
304 
305 	raw = DIV64_U64_ROUND_CLOSEST((u64)freq * BIT(16), sample_rate);
306 
307 	ret = regmap_update_bits(st->regmap, reg,
308 				 AXI_DAC_CHAN_CNTRL_2_FREQUENCY, raw);
309 	if (ret)
310 		return ret;
311 
312 	/* synchronize channels */
313 	return regmap_set_bits(st->regmap, AXI_DAC_CNTRL_1_REG,
314 			       AXI_DAC_CNTRL_1_SYNC);
315 }
316 
317 static int axi_dac_frequency_set(struct axi_dac_state *st,
318 				 const struct iio_chan_spec *chan,
319 				 const char *buf, size_t len, unsigned int tone_2)
320 {
321 	unsigned int freq;
322 	int ret;
323 
324 	ret = kstrtou32(buf, 10, &freq);
325 	if (ret)
326 		return ret;
327 
328 	guard(mutex)(&st->lock);
329 	ret = __axi_dac_frequency_set(st, chan->channel, st->dac_clk, freq,
330 				      tone_2);
331 	if (ret)
332 		return ret;
333 
334 	return len;
335 }
336 
337 static int axi_dac_scale_set(struct axi_dac_state *st,
338 			     const struct iio_chan_spec *chan,
339 			     const char *buf, size_t len, unsigned int tone_2)
340 {
341 	int integer, frac, scale;
342 	u32 raw = 0, reg;
343 	int ret;
344 
345 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &frac);
346 	if (ret)
347 		return ret;
348 
349 	scale = integer * MEGA + frac;
350 	if (scale <= -2 * (int)MEGA || scale >= 2 * (int)MEGA)
351 		return -EINVAL;
352 
353 	/*  format is 1.1.14 (sign, integer and fractional bits) */
354 	if (scale < 0) {
355 		raw = FIELD_PREP(AXI_DAC_CHAN_CNTRL_3_SCALE_SIGN, 1);
356 		scale *= -1;
357 	}
358 
359 	raw |= div_u64((u64)scale * AXI_DAC_CHAN_CNTRL_3_SCALE_INT, MEGA);
360 
361 	if (tone_2)
362 		reg = AXI_DAC_CHAN_CNTRL_3_REG(chan->channel);
363 	else
364 		reg = AXI_DAC_CHAN_CNTRL_1_REG(chan->channel);
365 
366 	guard(mutex)(&st->lock);
367 	ret = regmap_write(st->regmap, reg, raw);
368 	if (ret)
369 		return ret;
370 
371 	/* synchronize channels */
372 	ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_1_REG,
373 			      AXI_DAC_CNTRL_1_SYNC);
374 	if (ret)
375 		return ret;
376 
377 	return len;
378 }
379 
380 static int axi_dac_phase_set(struct axi_dac_state *st,
381 			     const struct iio_chan_spec *chan,
382 			     const char *buf, size_t len, unsigned int tone_2)
383 {
384 	int integer, frac, phase;
385 	u32 raw, reg;
386 	int ret;
387 
388 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &frac);
389 	if (ret)
390 		return ret;
391 
392 	phase = integer * MEGA + frac;
393 	if (phase < 0 || phase > AXI_DAC_2_PI_MEGA)
394 		return -EINVAL;
395 
396 	raw = DIV_ROUND_CLOSEST_ULL((u64)phase * U16_MAX, AXI_DAC_2_PI_MEGA);
397 
398 	if (tone_2)
399 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan->channel);
400 	else
401 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan->channel);
402 
403 	guard(mutex)(&st->lock);
404 	ret = regmap_update_bits(st->regmap, reg, AXI_DAC_CHAN_CNTRL_2_PHASE,
405 				 FIELD_PREP(AXI_DAC_CHAN_CNTRL_2_PHASE, raw));
406 	if (ret)
407 		return ret;
408 
409 	/* synchronize channels */
410 	ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_1_REG,
411 			      AXI_DAC_CNTRL_1_SYNC);
412 	if (ret)
413 		return ret;
414 
415 	return len;
416 }
417 
418 static int axi_dac_ext_info_set(struct iio_backend *back, uintptr_t private,
419 				const struct iio_chan_spec *chan,
420 				const char *buf, size_t len)
421 {
422 	struct axi_dac_state *st = iio_backend_get_priv(back);
423 
424 	switch (private) {
425 	case AXI_DAC_FREQ_TONE_1:
426 	case AXI_DAC_FREQ_TONE_2:
427 		return axi_dac_frequency_set(st, chan, buf, len,
428 					     private == AXI_DAC_FREQ_TONE_2);
429 	case AXI_DAC_SCALE_TONE_1:
430 	case AXI_DAC_SCALE_TONE_2:
431 		return axi_dac_scale_set(st, chan, buf, len,
432 					 private == AXI_DAC_SCALE_TONE_2);
433 	case AXI_DAC_PHASE_TONE_1:
434 	case AXI_DAC_PHASE_TONE_2:
435 		return axi_dac_phase_set(st, chan, buf, len,
436 					 private == AXI_DAC_PHASE_TONE_2);
437 	default:
438 		return -EOPNOTSUPP;
439 	}
440 }
441 
442 static int axi_dac_ext_info_get(struct iio_backend *back, uintptr_t private,
443 				const struct iio_chan_spec *chan, char *buf)
444 {
445 	struct axi_dac_state *st = iio_backend_get_priv(back);
446 
447 	switch (private) {
448 	case AXI_DAC_FREQ_TONE_1:
449 	case AXI_DAC_FREQ_TONE_2:
450 		return axi_dac_frequency_get(st, chan, buf,
451 					     private - AXI_DAC_FREQ_TONE_1);
452 	case AXI_DAC_SCALE_TONE_1:
453 	case AXI_DAC_SCALE_TONE_2:
454 		return axi_dac_scale_get(st, chan, buf,
455 					 private - AXI_DAC_SCALE_TONE_1);
456 	case AXI_DAC_PHASE_TONE_1:
457 	case AXI_DAC_PHASE_TONE_2:
458 		return axi_dac_phase_get(st, chan, buf,
459 					 private - AXI_DAC_PHASE_TONE_1);
460 	default:
461 		return -EOPNOTSUPP;
462 	}
463 }
464 
465 static const struct iio_chan_spec_ext_info axi_dac_ext_info[] = {
466 	IIO_BACKEND_EX_INFO("frequency0", IIO_SEPARATE, AXI_DAC_FREQ_TONE_1),
467 	IIO_BACKEND_EX_INFO("frequency1", IIO_SEPARATE, AXI_DAC_FREQ_TONE_2),
468 	IIO_BACKEND_EX_INFO("scale0", IIO_SEPARATE, AXI_DAC_SCALE_TONE_1),
469 	IIO_BACKEND_EX_INFO("scale1", IIO_SEPARATE, AXI_DAC_SCALE_TONE_2),
470 	IIO_BACKEND_EX_INFO("phase0", IIO_SEPARATE, AXI_DAC_PHASE_TONE_1),
471 	IIO_BACKEND_EX_INFO("phase1", IIO_SEPARATE, AXI_DAC_PHASE_TONE_2),
472 	{}
473 };
474 
475 static int axi_dac_extend_chan(struct iio_backend *back,
476 			       struct iio_chan_spec *chan)
477 {
478 	struct axi_dac_state *st = iio_backend_get_priv(back);
479 
480 	if (chan->type != IIO_ALTVOLTAGE)
481 		return -EINVAL;
482 	if (st->reg_config & AXI_DAC_CONFIG_DDS_DISABLE)
483 		/* nothing to extend */
484 		return 0;
485 
486 	chan->ext_info = axi_dac_ext_info;
487 
488 	return 0;
489 }
490 
491 static int axi_dac_data_source_set(struct iio_backend *back, unsigned int chan,
492 				   enum iio_backend_data_source data)
493 {
494 	struct axi_dac_state *st = iio_backend_get_priv(back);
495 
496 	switch (data) {
497 	case IIO_BACKEND_INTERNAL_CONTINUOUS_WAVE:
498 		return regmap_update_bits(st->regmap,
499 					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
500 					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
501 					  AXI_DAC_DATA_INTERNAL_TONE);
502 	case IIO_BACKEND_EXTERNAL:
503 		return regmap_update_bits(st->regmap,
504 					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
505 					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
506 					  AXI_DAC_DATA_DMA);
507 	case IIO_BACKEND_INTERNAL_RAMP_16BIT:
508 		return regmap_update_bits(st->regmap,
509 					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
510 					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
511 					  AXI_DAC_DATA_INTERNAL_RAMP_16BIT);
512 	default:
513 		return -EINVAL;
514 	}
515 }
516 
517 static int axi_dac_set_sample_rate(struct iio_backend *back, unsigned int chan,
518 				   u64 sample_rate)
519 {
520 	struct axi_dac_state *st = iio_backend_get_priv(back);
521 	unsigned int freq;
522 	int ret, tone;
523 
524 	if (!sample_rate)
525 		return -EINVAL;
526 	if (st->reg_config & AXI_DAC_CONFIG_DDS_DISABLE)
527 		/* sample_rate has no meaning if DDS is disabled */
528 		return 0;
529 
530 	guard(mutex)(&st->lock);
531 	/*
532 	 * If dac_clk is 0 then this must be the first time we're being notified
533 	 * about the interface sample rate. Hence, just update our internal
534 	 * variable and bail... If it's not 0, then we get the current DDS
535 	 * frequency (for the old rate) and update the registers for the new
536 	 * sample rate.
537 	 */
538 	if (!st->dac_clk) {
539 		st->dac_clk = sample_rate;
540 		return 0;
541 	}
542 
543 	for (tone = 0; tone <= AXI_DAC_FREQ_TONE_2; tone++) {
544 		ret = __axi_dac_frequency_get(st, chan, tone, &freq);
545 		if (ret)
546 			return ret;
547 
548 		ret = __axi_dac_frequency_set(st, chan, sample_rate, tone, freq);
549 		if (ret)
550 			return ret;
551 	}
552 
553 	st->dac_clk = sample_rate;
554 
555 	return 0;
556 }
557 
558 static int axi_dac_reg_access(struct iio_backend *back, unsigned int reg,
559 			      unsigned int writeval, unsigned int *readval)
560 {
561 	struct axi_dac_state *st = iio_backend_get_priv(back);
562 
563 	if (readval)
564 		return regmap_read(st->regmap, reg, readval);
565 
566 	return regmap_write(st->regmap, reg, writeval);
567 }
568 
569 static int axi_dac_ddr_enable(struct iio_backend *back)
570 {
571 	struct axi_dac_state *st = iio_backend_get_priv(back);
572 
573 	return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
574 				 AXI_DAC_CNTRL_2_SDR_DDR_N);
575 }
576 
577 static int axi_dac_ddr_disable(struct iio_backend *back)
578 {
579 	struct axi_dac_state *st = iio_backend_get_priv(back);
580 
581 	return regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
582 			       AXI_DAC_CNTRL_2_SDR_DDR_N);
583 }
584 
585 static int axi_dac_data_stream_enable(struct iio_backend *back)
586 {
587 	struct axi_dac_state *st = iio_backend_get_priv(back);
588 
589 	return regmap_set_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
590 			       AXI_DAC_CUSTOM_CTRL_STREAM_ENABLE);
591 }
592 
593 static int axi_dac_data_stream_disable(struct iio_backend *back)
594 {
595 	struct axi_dac_state *st = iio_backend_get_priv(back);
596 
597 	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
598 				 AXI_DAC_CUSTOM_CTRL_STREAM_ENABLE);
599 }
600 
601 static int axi_dac_data_transfer_addr(struct iio_backend *back, u32 address)
602 {
603 	struct axi_dac_state *st = iio_backend_get_priv(back);
604 
605 	if (address > FIELD_MAX(AXI_DAC_CUSTOM_CTRL_ADDRESS))
606 		return -EINVAL;
607 
608 	/*
609 	 * Sample register address, when the DAC is configured, or stream
610 	 * start address when the FSM is in stream state.
611 	 */
612 	return regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
613 				  AXI_DAC_CUSTOM_CTRL_ADDRESS,
614 				  FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS,
615 				  address));
616 }
617 
618 static int axi_dac_data_format_set(struct iio_backend *back, unsigned int ch,
619 				   const struct iio_backend_data_fmt *data)
620 {
621 	struct axi_dac_state *st = iio_backend_get_priv(back);
622 
623 	switch (data->type) {
624 	case IIO_BACKEND_DATA_UNSIGNED:
625 		return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
626 					 AXI_DAC_CNTRL_2_UNSIGNED_DATA);
627 	default:
628 		return -EINVAL;
629 	}
630 }
631 
632 static int __axi_dac_bus_reg_write(struct iio_backend *back, u32 reg,
633 				 u32 val, size_t data_size)
634 {
635 	struct axi_dac_state *st = iio_backend_get_priv(back);
636 	int ret;
637 	u32 ival;
638 
639 	/*
640 	 * Both AXI_DAC_CNTRL_2_REG and AXI_DAC_CUSTOM_WR_REG need to know
641 	 * the data size. So keeping data size control here only,
642 	 * since data size is mandatory for the current transfer.
643 	 * DDR state handled separately by specific backend calls,
644 	 * generally all raw register writes are SDR.
645 	 */
646 	if (data_size == sizeof(u16))
647 		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_16, val);
648 	else
649 		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_8, val);
650 
651 	ret = regmap_write(st->regmap, AXI_DAC_CUSTOM_WR_REG, ival);
652 	if (ret)
653 		return ret;
654 
655 	if (data_size == sizeof(u8))
656 		ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
657 				      AXI_DAC_CNTRL_2_SYMB_8B);
658 	else
659 		ret = regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
660 					AXI_DAC_CNTRL_2_SYMB_8B);
661 	if (ret)
662 		return ret;
663 
664 	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
665 				 AXI_DAC_CUSTOM_CTRL_ADDRESS,
666 				 FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS, reg));
667 	if (ret)
668 		return ret;
669 
670 	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
671 				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA,
672 				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
673 	if (ret)
674 		return ret;
675 
676 	ret = regmap_read_poll_timeout(st->regmap,
677 				AXI_DAC_UI_STATUS_REG, ival,
678 				FIELD_GET(AXI_DAC_UI_STATUS_IF_BUSY, ival) == 0,
679 				10, 100 * KILO);
680 	if (ret == -ETIMEDOUT)
681 		dev_err(st->dev, "AXI read timeout\n");
682 
683 	/* Cleaning always AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA */
684 	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
685 				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
686 }
687 
688 static int axi_dac_bus_reg_write(struct iio_backend *back, u32 reg,
689 					u32 val, size_t data_size)
690 {
691 	struct axi_dac_state *st = iio_backend_get_priv(back);
692 
693 	guard(mutex)(&st->lock);
694 	return __axi_dac_bus_reg_write(back, reg, val, data_size);
695 }
696 
697 static int axi_dac_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val,
698 				size_t data_size)
699 {
700 	struct axi_dac_state *st = iio_backend_get_priv(back);
701 	int ret;
702 
703 	guard(mutex)(&st->lock);
704 
705 	/*
706 	 * SPI, we write with read flag, then we read just at the AXI
707 	 * io address space to get data read.
708 	 */
709 	ret = __axi_dac_bus_reg_write(back, AXI_DAC_RD_ADDR(reg), 0,
710 				      data_size);
711 	if (ret)
712 		return ret;
713 
714 	return regmap_read(st->regmap, AXI_DAC_CUSTOM_RD_REG, val);
715 }
716 
717 static void axi_dac_child_remove(void *data)
718 {
719 	platform_device_unregister(data);
720 }
721 
722 static int axi_dac_create_platform_device(struct axi_dac_state *st,
723 					  struct fwnode_handle *child)
724 {
725 	struct ad3552r_hs_platform_data pdata = {
726 		.bus_reg_read = axi_dac_bus_reg_read,
727 		.bus_reg_write = axi_dac_bus_reg_write,
728 		.bus_sample_data_clock_hz = st->dac_clk_rate,
729 	};
730 	struct platform_device_info pi = {
731 		.parent = st->dev,
732 		.name = fwnode_get_name(child),
733 		.id = PLATFORM_DEVID_AUTO,
734 		.fwnode = child,
735 		.data = &pdata,
736 		.size_data = sizeof(pdata),
737 	};
738 	struct platform_device *pdev;
739 
740 	pdev = platform_device_register_full(&pi);
741 	if (IS_ERR(pdev))
742 		return PTR_ERR(pdev);
743 
744 	return devm_add_action_or_reset(st->dev, axi_dac_child_remove, pdev);
745 }
746 
747 static const struct iio_backend_ops axi_dac_generic_ops = {
748 	.enable = axi_dac_enable,
749 	.disable = axi_dac_disable,
750 	.request_buffer = axi_dac_request_buffer,
751 	.free_buffer = axi_dac_free_buffer,
752 	.extend_chan_spec = axi_dac_extend_chan,
753 	.ext_info_set = axi_dac_ext_info_set,
754 	.ext_info_get = axi_dac_ext_info_get,
755 	.data_source_set = axi_dac_data_source_set,
756 	.set_sample_rate = axi_dac_set_sample_rate,
757 	.debugfs_reg_access = iio_backend_debugfs_ptr(axi_dac_reg_access),
758 };
759 
760 static const struct iio_backend_ops axi_ad3552r_ops = {
761 	.enable = axi_dac_enable,
762 	.disable = axi_dac_disable,
763 	.request_buffer = axi_dac_request_buffer,
764 	.free_buffer = axi_dac_free_buffer,
765 	.data_source_set = axi_dac_data_source_set,
766 	.ddr_enable = axi_dac_ddr_enable,
767 	.ddr_disable = axi_dac_ddr_disable,
768 	.data_stream_enable = axi_dac_data_stream_enable,
769 	.data_stream_disable = axi_dac_data_stream_disable,
770 	.data_format_set = axi_dac_data_format_set,
771 	.data_transfer_addr = axi_dac_data_transfer_addr,
772 };
773 
774 static const struct iio_backend_info axi_dac_generic = {
775 	.name = "axi-dac",
776 	.ops = &axi_dac_generic_ops,
777 };
778 
779 static const struct iio_backend_info axi_ad3552r = {
780 	.name = "axi-ad3552r",
781 	.ops = &axi_ad3552r_ops,
782 };
783 
784 static const struct regmap_config axi_dac_regmap_config = {
785 	.val_bits = 32,
786 	.reg_bits = 32,
787 	.reg_stride = 4,
788 	.max_register = 0x0800,
789 };
790 
791 static int axi_dac_probe(struct platform_device *pdev)
792 {
793 	struct axi_dac_state *st;
794 	void __iomem *base;
795 	unsigned int ver;
796 	struct clk *clk;
797 	int ret;
798 
799 	st = devm_kzalloc(&pdev->dev, sizeof(*st), GFP_KERNEL);
800 	if (!st)
801 		return -ENOMEM;
802 
803 	st->info = device_get_match_data(&pdev->dev);
804 	if (!st->info)
805 		return -ENODEV;
806 	clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk");
807 	if (IS_ERR(clk)) {
808 		/* Backward compat., old fdt versions without clock-names. */
809 		clk = devm_clk_get_enabled(&pdev->dev, NULL);
810 		if (IS_ERR(clk))
811 			return dev_err_probe(&pdev->dev, PTR_ERR(clk),
812 					"failed to get clock\n");
813 	}
814 
815 	if (st->info->has_dac_clk) {
816 		struct clk *dac_clk;
817 
818 		dac_clk = devm_clk_get_enabled(&pdev->dev, "dac_clk");
819 		if (IS_ERR(dac_clk))
820 			return dev_err_probe(&pdev->dev, PTR_ERR(dac_clk),
821 					     "failed to get dac_clk clock\n");
822 
823 		/* We only care about the streaming mode rate */
824 		st->dac_clk_rate = clk_get_rate(dac_clk) / 2;
825 	}
826 
827 	base = devm_platform_ioremap_resource(pdev, 0);
828 	if (IS_ERR(base))
829 		return PTR_ERR(base);
830 
831 	st->dev = &pdev->dev;
832 	st->regmap = devm_regmap_init_mmio(&pdev->dev, base,
833 					   &axi_dac_regmap_config);
834 	if (IS_ERR(st->regmap))
835 		return dev_err_probe(&pdev->dev, PTR_ERR(st->regmap),
836 				     "failed to init register map\n");
837 
838 	/*
839 	 * Force disable the core. Up to the frontend to enable us. And we can
840 	 * still read/write registers...
841 	 */
842 	ret = regmap_write(st->regmap, AXI_DAC_RSTN_REG, 0);
843 	if (ret)
844 		return ret;
845 
846 	ret = regmap_read(st->regmap, ADI_AXI_REG_VERSION, &ver);
847 	if (ret)
848 		return ret;
849 
850 	if (ADI_AXI_PCORE_VER_MAJOR(ver) !=
851 		ADI_AXI_PCORE_VER_MAJOR(st->info->version)) {
852 		dev_err(&pdev->dev,
853 			"Major version mismatch. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
854 			ADI_AXI_PCORE_VER_MAJOR(st->info->version),
855 			ADI_AXI_PCORE_VER_MINOR(st->info->version),
856 			ADI_AXI_PCORE_VER_PATCH(st->info->version),
857 			ADI_AXI_PCORE_VER_MAJOR(ver),
858 			ADI_AXI_PCORE_VER_MINOR(ver),
859 			ADI_AXI_PCORE_VER_PATCH(ver));
860 		return -ENODEV;
861 	}
862 
863 	/* Let's get the core read only configuration */
864 	ret = regmap_read(st->regmap, AXI_DAC_CONFIG_REG, &st->reg_config);
865 	if (ret)
866 		return ret;
867 
868 	/*
869 	 * In some designs, setting the R1_MODE bit to 0 (which is the default
870 	 * value) causes all channels of the frontend to be routed to the same
871 	 * DMA (so they are sampled together). This is for things like
872 	 * Multiple-Input and Multiple-Output (MIMO). As most of the times we
873 	 * want independent channels let's override the core's default value and
874 	 * set the R1_MODE bit.
875 	 */
876 	ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
877 			      ADI_DAC_CNTRL_2_R1_MODE);
878 	if (ret)
879 		return ret;
880 
881 	mutex_init(&st->lock);
882 
883 	ret = devm_iio_backend_register(&pdev->dev, st->info->backend_info, st);
884 	if (ret)
885 		return dev_err_probe(&pdev->dev, ret,
886 				     "failed to register iio backend\n");
887 
888 	device_for_each_child_node_scoped(&pdev->dev, child) {
889 		int val;
890 
891 		if (!st->info->has_child_nodes)
892 			return dev_err_probe(&pdev->dev, -EINVAL,
893 					     "invalid fdt axi-dac compatible.");
894 
895 		/* Processing only reg 0 node */
896 		ret = fwnode_property_read_u32(child, "reg", &val);
897 		if (ret)
898 			return dev_err_probe(&pdev->dev, ret,
899 						"invalid reg property.");
900 		if (val != 0)
901 			return dev_err_probe(&pdev->dev, -EINVAL,
902 						"invalid node address.");
903 
904 		ret = axi_dac_create_platform_device(st, child);
905 		if (ret)
906 			return dev_err_probe(&pdev->dev, -EINVAL,
907 						"cannot create device.");
908 	}
909 
910 	dev_info(&pdev->dev, "AXI DAC IP core (%d.%.2d.%c) probed\n",
911 		 ADI_AXI_PCORE_VER_MAJOR(ver),
912 		 ADI_AXI_PCORE_VER_MINOR(ver),
913 		 ADI_AXI_PCORE_VER_PATCH(ver));
914 
915 	return 0;
916 }
917 
918 static const struct axi_dac_info dac_generic = {
919 	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
920 	.backend_info = &axi_dac_generic,
921 };
922 
923 static const struct axi_dac_info dac_ad3552r = {
924 	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
925 	.backend_info = &axi_ad3552r,
926 	.has_dac_clk = true,
927 	.has_child_nodes = true,
928 };
929 
930 static const struct of_device_id axi_dac_of_match[] = {
931 	{ .compatible = "adi,axi-dac-9.1.b", .data = &dac_generic },
932 	{ .compatible = "adi,axi-ad3552r", .data = &dac_ad3552r },
933 	{}
934 };
935 MODULE_DEVICE_TABLE(of, axi_dac_of_match);
936 
937 static struct platform_driver axi_dac_driver = {
938 	.driver = {
939 		.name = "adi-axi-dac",
940 		.of_match_table = axi_dac_of_match,
941 	},
942 	.probe = axi_dac_probe,
943 };
944 module_platform_driver(axi_dac_driver);
945 
946 MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
947 MODULE_DESCRIPTION("Analog Devices Generic AXI DAC IP core driver");
948 MODULE_LICENSE("GPL");
949 MODULE_IMPORT_NS(IIO_DMAENGINE_BUFFER);
950 MODULE_IMPORT_NS(IIO_BACKEND);
951