xref: /linux/drivers/iio/dac/adi-axi-dac.c (revision e9ef810dfee7a2227da9d423aecb0ced35faddbe)
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/adi-axi-common.h>
9 #include <linux/bitfield.h>
10 #include <linux/bits.h>
11 #include <linux/cleanup.h>
12 #include <linux/clk.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/limits.h>
16 #include <linux/kstrtox.h>
17 #include <linux/math.h>
18 #include <linux/math64.h>
19 #include <linux/module.h>
20 #include <linux/mod_devicetable.h>
21 #include <linux/mutex.h>
22 #include <linux/platform_device.h>
23 #include <linux/property.h>
24 #include <linux/regmap.h>
25 #include <linux/units.h>
26 
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_MULTI_IO_MODE	GENMASK(3, 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_CHAN_CNTRL_MAX			15
88 #define AXI_DAC_RD_ADDR(x)			(BIT(7) | (x))
89 
90 /* 360 degrees in rad */
91 #define AXI_DAC_2_PI_MEGA			6283190
92 
93 enum {
94 	AXI_DAC_DATA_INTERNAL_TONE,
95 	AXI_DAC_DATA_DMA = 2,
96 	AXI_DAC_DATA_INTERNAL_RAMP_16BIT = 11,
97 };
98 
99 struct axi_dac_info {
100 	unsigned int version;
101 	const struct iio_backend_info *backend_info;
102 	bool has_dac_clk;
103 	bool has_child_nodes;
104 };
105 
106 struct axi_dac_state {
107 	struct regmap *regmap;
108 	struct device *dev;
109 	/*
110 	 * lock to protect multiple accesses to the device registers and global
111 	 * data/variables.
112 	 */
113 	struct mutex lock;
114 	const struct axi_dac_info *info;
115 	u64 dac_clk;
116 	u32 reg_config;
117 	bool int_tone;
118 	int dac_clk_rate;
119 };
120 
axi_dac_enable(struct iio_backend * back)121 static int axi_dac_enable(struct iio_backend *back)
122 {
123 	struct axi_dac_state *st = iio_backend_get_priv(back);
124 	unsigned int __val;
125 	int ret;
126 
127 	guard(mutex)(&st->lock);
128 	ret = regmap_set_bits(st->regmap, AXI_DAC_RSTN_REG,
129 			      AXI_DAC_RSTN_MMCM_RSTN);
130 	if (ret)
131 		return ret;
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, AXI_DAC_DRP_STATUS_REG,
138 				       __val,
139 				       __val & AXI_DAC_DRP_STATUS_DRP_LOCKED,
140 				       100, 1000);
141 	if (ret)
142 		return ret;
143 
144 	return regmap_set_bits(st->regmap, AXI_DAC_RSTN_REG,
145 			       AXI_DAC_RSTN_RSTN | AXI_DAC_RSTN_MMCM_RSTN);
146 }
147 
axi_dac_disable(struct iio_backend * back)148 static void axi_dac_disable(struct iio_backend *back)
149 {
150 	struct axi_dac_state *st = iio_backend_get_priv(back);
151 
152 	guard(mutex)(&st->lock);
153 	regmap_write(st->regmap, AXI_DAC_RSTN_REG, 0);
154 }
155 
axi_dac_request_buffer(struct iio_backend * back,struct iio_dev * indio_dev)156 static struct iio_buffer *axi_dac_request_buffer(struct iio_backend *back,
157 						 struct iio_dev *indio_dev)
158 {
159 	struct axi_dac_state *st = iio_backend_get_priv(back);
160 	const char *dma_name;
161 
162 	if (device_property_read_string(st->dev, "dma-names", &dma_name))
163 		dma_name = "tx";
164 
165 	return iio_dmaengine_buffer_setup_ext(st->dev, indio_dev, dma_name,
166 					      IIO_BUFFER_DIRECTION_OUT);
167 }
168 
axi_dac_free_buffer(struct iio_backend * back,struct iio_buffer * buffer)169 static void axi_dac_free_buffer(struct iio_backend *back,
170 				struct iio_buffer *buffer)
171 {
172 	iio_dmaengine_buffer_teardown(buffer);
173 }
174 
175 enum {
176 	AXI_DAC_FREQ_TONE_1,
177 	AXI_DAC_FREQ_TONE_2,
178 	AXI_DAC_SCALE_TONE_1,
179 	AXI_DAC_SCALE_TONE_2,
180 	AXI_DAC_PHASE_TONE_1,
181 	AXI_DAC_PHASE_TONE_2,
182 };
183 
__axi_dac_frequency_get(struct axi_dac_state * st,unsigned int chan,unsigned int tone_2,unsigned int * freq)184 static int __axi_dac_frequency_get(struct axi_dac_state *st, unsigned int chan,
185 				   unsigned int tone_2, unsigned int *freq)
186 {
187 	u32 reg, raw;
188 	int ret;
189 
190 	if (chan > AXI_DAC_CHAN_CNTRL_MAX)
191 		return -EINVAL;
192 
193 	if (!st->dac_clk) {
194 		dev_err(st->dev, "Sampling rate is 0...\n");
195 		return -EINVAL;
196 	}
197 
198 	if (tone_2)
199 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan);
200 	else
201 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan);
202 
203 	ret = regmap_read(st->regmap, reg, &raw);
204 	if (ret)
205 		return ret;
206 
207 	raw = FIELD_GET(AXI_DAC_CHAN_CNTRL_2_FREQUENCY, raw);
208 	*freq = DIV_ROUND_CLOSEST_ULL(raw * st->dac_clk, BIT(16));
209 
210 	return 0;
211 }
212 
axi_dac_frequency_get(struct axi_dac_state * st,const struct iio_chan_spec * chan,char * buf,unsigned int tone_2)213 static int axi_dac_frequency_get(struct axi_dac_state *st,
214 				 const struct iio_chan_spec *chan, char *buf,
215 				 unsigned int tone_2)
216 {
217 	unsigned int freq;
218 	int ret;
219 
220 	scoped_guard(mutex, &st->lock) {
221 		ret = __axi_dac_frequency_get(st, chan->channel, tone_2, &freq);
222 		if (ret)
223 			return ret;
224 	}
225 
226 	return sysfs_emit(buf, "%u\n", freq);
227 }
228 
axi_dac_scale_get(struct axi_dac_state * st,const struct iio_chan_spec * chan,char * buf,unsigned int tone_2)229 static int axi_dac_scale_get(struct axi_dac_state *st,
230 			     const struct iio_chan_spec *chan, char *buf,
231 			     unsigned int tone_2)
232 {
233 	unsigned int scale, sign;
234 	int ret, vals[2];
235 	u32 reg, raw;
236 
237 	if (chan->channel > AXI_DAC_CHAN_CNTRL_MAX)
238 		return -EINVAL;
239 
240 	if (tone_2)
241 		reg = AXI_DAC_CHAN_CNTRL_3_REG(chan->channel);
242 	else
243 		reg = AXI_DAC_CHAN_CNTRL_1_REG(chan->channel);
244 
245 	ret = regmap_read(st->regmap, reg, &raw);
246 	if (ret)
247 		return ret;
248 
249 	sign = FIELD_GET(AXI_DAC_CHAN_CNTRL_3_SCALE_SIGN, raw);
250 	raw = FIELD_GET(AXI_DAC_CHAN_CNTRL_3_SCALE, raw);
251 	scale = DIV_ROUND_CLOSEST_ULL((u64)raw * MEGA,
252 				      AXI_DAC_CHAN_CNTRL_3_SCALE_INT);
253 
254 	vals[0] = scale / MEGA;
255 	vals[1] = scale % MEGA;
256 
257 	if (sign) {
258 		vals[0] *= -1;
259 		if (!vals[0])
260 			vals[1] *= -1;
261 	}
262 
263 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, ARRAY_SIZE(vals),
264 				vals);
265 }
266 
axi_dac_phase_get(struct axi_dac_state * st,const struct iio_chan_spec * chan,char * buf,unsigned int tone_2)267 static int axi_dac_phase_get(struct axi_dac_state *st,
268 			     const struct iio_chan_spec *chan, char *buf,
269 			     unsigned int tone_2)
270 {
271 	u32 reg, raw, phase;
272 	int ret, vals[2];
273 
274 	if (chan->channel > AXI_DAC_CHAN_CNTRL_MAX)
275 		return -EINVAL;
276 
277 	if (tone_2)
278 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan->channel);
279 	else
280 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan->channel);
281 
282 	ret = regmap_read(st->regmap, reg, &raw);
283 	if (ret)
284 		return ret;
285 
286 	raw = FIELD_GET(AXI_DAC_CHAN_CNTRL_2_PHASE, raw);
287 	phase = DIV_ROUND_CLOSEST_ULL((u64)raw * AXI_DAC_2_PI_MEGA, U16_MAX);
288 
289 	vals[0] = phase / MEGA;
290 	vals[1] = phase % MEGA;
291 
292 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, ARRAY_SIZE(vals),
293 				vals);
294 }
295 
__axi_dac_frequency_set(struct axi_dac_state * st,unsigned int chan,u64 sample_rate,unsigned int freq,unsigned int tone_2)296 static int __axi_dac_frequency_set(struct axi_dac_state *st, unsigned int chan,
297 				   u64 sample_rate, unsigned int freq,
298 				   unsigned int tone_2)
299 {
300 	u32 reg;
301 	u16 raw;
302 	int ret;
303 
304 	if (chan > AXI_DAC_CHAN_CNTRL_MAX)
305 		return -EINVAL;
306 
307 	if (!sample_rate || freq > sample_rate / 2) {
308 		dev_err(st->dev, "Invalid frequency(%u) dac_clk(%llu)\n",
309 			freq, sample_rate);
310 		return -EINVAL;
311 	}
312 
313 	if (tone_2)
314 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan);
315 	else
316 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan);
317 
318 	raw = DIV64_U64_ROUND_CLOSEST((u64)freq * BIT(16), sample_rate);
319 
320 	ret = regmap_update_bits(st->regmap, reg,
321 				 AXI_DAC_CHAN_CNTRL_2_FREQUENCY, raw);
322 	if (ret)
323 		return ret;
324 
325 	/* synchronize channels */
326 	return regmap_set_bits(st->regmap, AXI_DAC_CNTRL_1_REG,
327 			       AXI_DAC_CNTRL_1_SYNC);
328 }
329 
axi_dac_frequency_set(struct axi_dac_state * st,const struct iio_chan_spec * chan,const char * buf,size_t len,unsigned int tone_2)330 static int axi_dac_frequency_set(struct axi_dac_state *st,
331 				 const struct iio_chan_spec *chan,
332 				 const char *buf, size_t len, unsigned int tone_2)
333 {
334 	unsigned int freq;
335 	int ret;
336 
337 	ret = kstrtou32(buf, 10, &freq);
338 	if (ret)
339 		return ret;
340 
341 	guard(mutex)(&st->lock);
342 	ret = __axi_dac_frequency_set(st, chan->channel, st->dac_clk, freq,
343 				      tone_2);
344 	if (ret)
345 		return ret;
346 
347 	return len;
348 }
349 
axi_dac_scale_set(struct axi_dac_state * st,const struct iio_chan_spec * chan,const char * buf,size_t len,unsigned int tone_2)350 static int axi_dac_scale_set(struct axi_dac_state *st,
351 			     const struct iio_chan_spec *chan,
352 			     const char *buf, size_t len, unsigned int tone_2)
353 {
354 	int integer, frac, scale;
355 	u32 raw = 0, reg;
356 	int ret;
357 
358 	if (chan->channel > AXI_DAC_CHAN_CNTRL_MAX)
359 		return -EINVAL;
360 
361 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &frac);
362 	if (ret)
363 		return ret;
364 
365 	scale = integer * MEGA + frac;
366 	if (scale <= -2 * (int)MEGA || scale >= 2 * (int)MEGA)
367 		return -EINVAL;
368 
369 	/*  format is 1.1.14 (sign, integer and fractional bits) */
370 	if (scale < 0) {
371 		raw = FIELD_PREP(AXI_DAC_CHAN_CNTRL_3_SCALE_SIGN, 1);
372 		scale *= -1;
373 	}
374 
375 	raw |= div_u64((u64)scale * AXI_DAC_CHAN_CNTRL_3_SCALE_INT, MEGA);
376 
377 	if (tone_2)
378 		reg = AXI_DAC_CHAN_CNTRL_3_REG(chan->channel);
379 	else
380 		reg = AXI_DAC_CHAN_CNTRL_1_REG(chan->channel);
381 
382 	guard(mutex)(&st->lock);
383 	ret = regmap_write(st->regmap, reg, raw);
384 	if (ret)
385 		return ret;
386 
387 	/* synchronize channels */
388 	ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_1_REG,
389 			      AXI_DAC_CNTRL_1_SYNC);
390 	if (ret)
391 		return ret;
392 
393 	return len;
394 }
395 
axi_dac_phase_set(struct axi_dac_state * st,const struct iio_chan_spec * chan,const char * buf,size_t len,unsigned int tone_2)396 static int axi_dac_phase_set(struct axi_dac_state *st,
397 			     const struct iio_chan_spec *chan,
398 			     const char *buf, size_t len, unsigned int tone_2)
399 {
400 	int integer, frac, phase;
401 	u32 raw, reg;
402 	int ret;
403 
404 	if (chan->channel > AXI_DAC_CHAN_CNTRL_MAX)
405 		return -EINVAL;
406 
407 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &frac);
408 	if (ret)
409 		return ret;
410 
411 	phase = integer * MEGA + frac;
412 	if (phase < 0 || phase > AXI_DAC_2_PI_MEGA)
413 		return -EINVAL;
414 
415 	raw = DIV_ROUND_CLOSEST_ULL((u64)phase * U16_MAX, AXI_DAC_2_PI_MEGA);
416 
417 	if (tone_2)
418 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan->channel);
419 	else
420 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan->channel);
421 
422 	guard(mutex)(&st->lock);
423 	ret = regmap_update_bits(st->regmap, reg, AXI_DAC_CHAN_CNTRL_2_PHASE,
424 				 FIELD_PREP(AXI_DAC_CHAN_CNTRL_2_PHASE, raw));
425 	if (ret)
426 		return ret;
427 
428 	/* synchronize channels */
429 	ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_1_REG,
430 			      AXI_DAC_CNTRL_1_SYNC);
431 	if (ret)
432 		return ret;
433 
434 	return len;
435 }
436 
axi_dac_ext_info_set(struct iio_backend * back,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)437 static int axi_dac_ext_info_set(struct iio_backend *back, uintptr_t private,
438 				const struct iio_chan_spec *chan,
439 				const char *buf, size_t len)
440 {
441 	struct axi_dac_state *st = iio_backend_get_priv(back);
442 
443 	switch (private) {
444 	case AXI_DAC_FREQ_TONE_1:
445 	case AXI_DAC_FREQ_TONE_2:
446 		return axi_dac_frequency_set(st, chan, buf, len,
447 					     private == AXI_DAC_FREQ_TONE_2);
448 	case AXI_DAC_SCALE_TONE_1:
449 	case AXI_DAC_SCALE_TONE_2:
450 		return axi_dac_scale_set(st, chan, buf, len,
451 					 private == AXI_DAC_SCALE_TONE_2);
452 	case AXI_DAC_PHASE_TONE_1:
453 	case AXI_DAC_PHASE_TONE_2:
454 		return axi_dac_phase_set(st, chan, buf, len,
455 					 private == AXI_DAC_PHASE_TONE_2);
456 	default:
457 		return -EOPNOTSUPP;
458 	}
459 }
460 
axi_dac_ext_info_get(struct iio_backend * back,uintptr_t private,const struct iio_chan_spec * chan,char * buf)461 static int axi_dac_ext_info_get(struct iio_backend *back, uintptr_t private,
462 				const struct iio_chan_spec *chan, char *buf)
463 {
464 	struct axi_dac_state *st = iio_backend_get_priv(back);
465 
466 	switch (private) {
467 	case AXI_DAC_FREQ_TONE_1:
468 	case AXI_DAC_FREQ_TONE_2:
469 		return axi_dac_frequency_get(st, chan, buf,
470 					     private - AXI_DAC_FREQ_TONE_1);
471 	case AXI_DAC_SCALE_TONE_1:
472 	case AXI_DAC_SCALE_TONE_2:
473 		return axi_dac_scale_get(st, chan, buf,
474 					 private - AXI_DAC_SCALE_TONE_1);
475 	case AXI_DAC_PHASE_TONE_1:
476 	case AXI_DAC_PHASE_TONE_2:
477 		return axi_dac_phase_get(st, chan, buf,
478 					 private - AXI_DAC_PHASE_TONE_1);
479 	default:
480 		return -EOPNOTSUPP;
481 	}
482 }
483 
484 static const struct iio_chan_spec_ext_info axi_dac_ext_info[] = {
485 	IIO_BACKEND_EX_INFO("frequency0", IIO_SEPARATE, AXI_DAC_FREQ_TONE_1),
486 	IIO_BACKEND_EX_INFO("frequency1", IIO_SEPARATE, AXI_DAC_FREQ_TONE_2),
487 	IIO_BACKEND_EX_INFO("scale0", IIO_SEPARATE, AXI_DAC_SCALE_TONE_1),
488 	IIO_BACKEND_EX_INFO("scale1", IIO_SEPARATE, AXI_DAC_SCALE_TONE_2),
489 	IIO_BACKEND_EX_INFO("phase0", IIO_SEPARATE, AXI_DAC_PHASE_TONE_1),
490 	IIO_BACKEND_EX_INFO("phase1", IIO_SEPARATE, AXI_DAC_PHASE_TONE_2),
491 	{ }
492 };
493 
axi_dac_extend_chan(struct iio_backend * back,struct iio_chan_spec * chan)494 static int axi_dac_extend_chan(struct iio_backend *back,
495 			       struct iio_chan_spec *chan)
496 {
497 	struct axi_dac_state *st = iio_backend_get_priv(back);
498 
499 	if (chan->type != IIO_ALTVOLTAGE)
500 		return -EINVAL;
501 	if (st->reg_config & AXI_DAC_CONFIG_DDS_DISABLE)
502 		/* nothing to extend */
503 		return 0;
504 
505 	chan->ext_info = axi_dac_ext_info;
506 
507 	return 0;
508 }
509 
axi_dac_data_source_set(struct iio_backend * back,unsigned int chan,enum iio_backend_data_source data)510 static int axi_dac_data_source_set(struct iio_backend *back, unsigned int chan,
511 				   enum iio_backend_data_source data)
512 {
513 	struct axi_dac_state *st = iio_backend_get_priv(back);
514 
515 	if (chan > AXI_DAC_CHAN_CNTRL_MAX)
516 		return -EINVAL;
517 
518 	switch (data) {
519 	case IIO_BACKEND_INTERNAL_CONTINUOUS_WAVE:
520 		return regmap_update_bits(st->regmap,
521 					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
522 					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
523 					  AXI_DAC_DATA_INTERNAL_TONE);
524 	case IIO_BACKEND_EXTERNAL:
525 		return regmap_update_bits(st->regmap,
526 					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
527 					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
528 					  AXI_DAC_DATA_DMA);
529 	case IIO_BACKEND_INTERNAL_RAMP_16BIT:
530 		return regmap_update_bits(st->regmap,
531 					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
532 					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
533 					  AXI_DAC_DATA_INTERNAL_RAMP_16BIT);
534 	default:
535 		return -EINVAL;
536 	}
537 }
538 
axi_dac_data_source_get(struct iio_backend * back,unsigned int chan,enum iio_backend_data_source * data)539 static int axi_dac_data_source_get(struct iio_backend *back, unsigned int chan,
540 				   enum iio_backend_data_source *data)
541 {
542 	struct axi_dac_state *st = iio_backend_get_priv(back);
543 	int ret;
544 	u32 val;
545 
546 	if (chan > AXI_DAC_CHAN_CNTRL_MAX)
547 		return -EINVAL;
548 
549 	ret = regmap_read(st->regmap, AXI_DAC_CHAN_CNTRL_7_REG(chan), &val);
550 	if (ret)
551 		return ret;
552 
553 	switch (val) {
554 	case AXI_DAC_DATA_INTERNAL_TONE:
555 		*data = IIO_BACKEND_INTERNAL_CONTINUOUS_WAVE;
556 		return 0;
557 	case AXI_DAC_DATA_DMA:
558 		*data = IIO_BACKEND_EXTERNAL;
559 		return 0;
560 	case AXI_DAC_DATA_INTERNAL_RAMP_16BIT:
561 		*data = IIO_BACKEND_INTERNAL_RAMP_16BIT;
562 		return 0;
563 	default:
564 		return -EIO;
565 	}
566 }
567 
axi_dac_set_sample_rate(struct iio_backend * back,unsigned int chan,u64 sample_rate)568 static int axi_dac_set_sample_rate(struct iio_backend *back, unsigned int chan,
569 				   u64 sample_rate)
570 {
571 	struct axi_dac_state *st = iio_backend_get_priv(back);
572 	unsigned int freq;
573 	int ret, tone;
574 
575 	if (chan > AXI_DAC_CHAN_CNTRL_MAX)
576 		return -EINVAL;
577 	if (!sample_rate)
578 		return -EINVAL;
579 	if (st->reg_config & AXI_DAC_CONFIG_DDS_DISABLE)
580 		/* sample_rate has no meaning if DDS is disabled */
581 		return 0;
582 
583 	guard(mutex)(&st->lock);
584 	/*
585 	 * If dac_clk is 0 then this must be the first time we're being notified
586 	 * about the interface sample rate. Hence, just update our internal
587 	 * variable and bail... If it's not 0, then we get the current DDS
588 	 * frequency (for the old rate) and update the registers for the new
589 	 * sample rate.
590 	 */
591 	if (!st->dac_clk) {
592 		st->dac_clk = sample_rate;
593 		return 0;
594 	}
595 
596 	for (tone = 0; tone <= AXI_DAC_FREQ_TONE_2; tone++) {
597 		ret = __axi_dac_frequency_get(st, chan, tone, &freq);
598 		if (ret)
599 			return ret;
600 
601 		ret = __axi_dac_frequency_set(st, chan, sample_rate, tone, freq);
602 		if (ret)
603 			return ret;
604 	}
605 
606 	st->dac_clk = sample_rate;
607 
608 	return 0;
609 }
610 
axi_dac_reg_access(struct iio_backend * back,unsigned int reg,unsigned int writeval,unsigned int * readval)611 static int axi_dac_reg_access(struct iio_backend *back, unsigned int reg,
612 			      unsigned int writeval, unsigned int *readval)
613 {
614 	struct axi_dac_state *st = iio_backend_get_priv(back);
615 
616 	if (readval)
617 		return regmap_read(st->regmap, reg, readval);
618 
619 	return regmap_write(st->regmap, reg, writeval);
620 }
621 
axi_dac_ddr_enable(struct iio_backend * back)622 static int axi_dac_ddr_enable(struct iio_backend *back)
623 {
624 	struct axi_dac_state *st = iio_backend_get_priv(back);
625 
626 	return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
627 				 AXI_DAC_CNTRL_2_SDR_DDR_N);
628 }
629 
axi_dac_ddr_disable(struct iio_backend * back)630 static int axi_dac_ddr_disable(struct iio_backend *back)
631 {
632 	struct axi_dac_state *st = iio_backend_get_priv(back);
633 
634 	return regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
635 			       AXI_DAC_CNTRL_2_SDR_DDR_N);
636 }
637 
axi_dac_wait_bus_free(struct axi_dac_state * st)638 static int axi_dac_wait_bus_free(struct axi_dac_state *st)
639 {
640 	u32 val;
641 	int ret;
642 
643 	ret = regmap_read_poll_timeout(st->regmap, AXI_DAC_UI_STATUS_REG, val,
644 		FIELD_GET(AXI_DAC_UI_STATUS_IF_BUSY, val) == 0, 10,
645 		100 * KILO);
646 	if (ret == -ETIMEDOUT)
647 		dev_err(st->dev, "AXI bus timeout\n");
648 
649 	return ret;
650 }
651 
axi_dac_data_stream_enable(struct iio_backend * back)652 static int axi_dac_data_stream_enable(struct iio_backend *back)
653 {
654 	struct axi_dac_state *st = iio_backend_get_priv(back);
655 	int ret;
656 
657 	ret = axi_dac_wait_bus_free(st);
658 	if (ret)
659 		return ret;
660 
661 	return regmap_set_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
662 			       AXI_DAC_CUSTOM_CTRL_STREAM_ENABLE);
663 }
664 
axi_dac_data_stream_disable(struct iio_backend * back)665 static int axi_dac_data_stream_disable(struct iio_backend *back)
666 {
667 	struct axi_dac_state *st = iio_backend_get_priv(back);
668 
669 	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
670 				 AXI_DAC_CUSTOM_CTRL_STREAM_ENABLE);
671 }
672 
axi_dac_data_transfer_addr(struct iio_backend * back,u32 address)673 static int axi_dac_data_transfer_addr(struct iio_backend *back, u32 address)
674 {
675 	struct axi_dac_state *st = iio_backend_get_priv(back);
676 
677 	if (address > FIELD_MAX(AXI_DAC_CUSTOM_CTRL_ADDRESS))
678 		return -EINVAL;
679 
680 	/*
681 	 * Sample register address, when the DAC is configured, or stream
682 	 * start address when the FSM is in stream state.
683 	 */
684 	return regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
685 				  AXI_DAC_CUSTOM_CTRL_ADDRESS,
686 				  FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS,
687 				  address));
688 }
689 
axi_dac_data_format_set(struct iio_backend * back,unsigned int ch,const struct iio_backend_data_fmt * data)690 static int axi_dac_data_format_set(struct iio_backend *back, unsigned int ch,
691 				   const struct iio_backend_data_fmt *data)
692 {
693 	struct axi_dac_state *st = iio_backend_get_priv(back);
694 
695 	switch (data->type) {
696 	case IIO_BACKEND_DATA_UNSIGNED:
697 		return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
698 					 AXI_DAC_CNTRL_2_UNSIGNED_DATA);
699 	default:
700 		return -EINVAL;
701 	}
702 }
703 
__axi_dac_bus_reg_write(struct iio_backend * back,u32 reg,u32 val,size_t data_size)704 static int __axi_dac_bus_reg_write(struct iio_backend *back, u32 reg,
705 				 u32 val, size_t data_size)
706 {
707 	struct axi_dac_state *st = iio_backend_get_priv(back);
708 	int ret;
709 	u32 ival;
710 
711 	/*
712 	 * Both AXI_DAC_CNTRL_2_REG and AXI_DAC_CUSTOM_WR_REG need to know
713 	 * the data size. So keeping data size control here only,
714 	 * since data size is mandatory for the current transfer.
715 	 * DDR state handled separately by specific backend calls,
716 	 * generally all raw register writes are SDR.
717 	 */
718 	if (data_size == sizeof(u16))
719 		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_16, val);
720 	else
721 		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_8, val);
722 
723 	ret = regmap_write(st->regmap, AXI_DAC_CUSTOM_WR_REG, ival);
724 	if (ret)
725 		return ret;
726 
727 	if (data_size == sizeof(u8))
728 		ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
729 				      AXI_DAC_CNTRL_2_SYMB_8B);
730 	else
731 		ret = regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
732 					AXI_DAC_CNTRL_2_SYMB_8B);
733 	if (ret)
734 		return ret;
735 
736 	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
737 				 AXI_DAC_CUSTOM_CTRL_ADDRESS,
738 				 FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS, reg));
739 	if (ret)
740 		return ret;
741 
742 	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
743 				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA,
744 				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
745 	if (ret)
746 		return ret;
747 
748 	ret = axi_dac_wait_bus_free(st);
749 	if (ret)
750 		return ret;
751 
752 	/* Cleaning always AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA */
753 	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
754 				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
755 }
756 
axi_dac_bus_reg_write(struct iio_backend * back,u32 reg,u32 val,size_t data_size)757 static int axi_dac_bus_reg_write(struct iio_backend *back, u32 reg,
758 					u32 val, size_t data_size)
759 {
760 	struct axi_dac_state *st = iio_backend_get_priv(back);
761 
762 	guard(mutex)(&st->lock);
763 	return __axi_dac_bus_reg_write(back, reg, val, data_size);
764 }
765 
axi_dac_bus_reg_read(struct iio_backend * back,u32 reg,u32 * val,size_t data_size)766 static int axi_dac_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val,
767 				size_t data_size)
768 {
769 	struct axi_dac_state *st = iio_backend_get_priv(back);
770 	int ret;
771 
772 	guard(mutex)(&st->lock);
773 
774 	/*
775 	 * SPI, we write with read flag, then we read just at the AXI
776 	 * io address space to get data read.
777 	 */
778 	ret = __axi_dac_bus_reg_write(back, AXI_DAC_RD_ADDR(reg), 0,
779 				      data_size);
780 	if (ret)
781 		return ret;
782 
783 	ret = axi_dac_wait_bus_free(st);
784 	if (ret)
785 		return ret;
786 
787 	return regmap_read(st->regmap, AXI_DAC_CUSTOM_RD_REG, val);
788 }
789 
axi_dac_bus_set_io_mode(struct iio_backend * back,enum ad3552r_io_mode mode)790 static int axi_dac_bus_set_io_mode(struct iio_backend *back,
791 				   enum ad3552r_io_mode mode)
792 {
793 	struct axi_dac_state *st = iio_backend_get_priv(back);
794 	int ret;
795 
796 	if (mode > AD3552R_IO_MODE_QSPI)
797 		return -EINVAL;
798 
799 	guard(mutex)(&st->lock);
800 
801 	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
802 			AXI_DAC_CUSTOM_CTRL_MULTI_IO_MODE,
803 			FIELD_PREP(AXI_DAC_CUSTOM_CTRL_MULTI_IO_MODE, mode));
804 	if (ret)
805 		return ret;
806 
807 	return axi_dac_wait_bus_free(st);
808 }
809 
axi_dac_child_remove(void * data)810 static void axi_dac_child_remove(void *data)
811 {
812 	platform_device_unregister(data);
813 }
814 
axi_dac_create_platform_device(struct axi_dac_state * st,struct fwnode_handle * child)815 static int axi_dac_create_platform_device(struct axi_dac_state *st,
816 					  struct fwnode_handle *child)
817 {
818 	struct ad3552r_hs_platform_data pdata = {
819 		.bus_reg_read = axi_dac_bus_reg_read,
820 		.bus_reg_write = axi_dac_bus_reg_write,
821 		.bus_set_io_mode = axi_dac_bus_set_io_mode,
822 		.bus_sample_data_clock_hz = st->dac_clk_rate,
823 	};
824 	struct platform_device_info pi = {
825 		.parent = st->dev,
826 		.name = fwnode_get_name(child),
827 		.id = PLATFORM_DEVID_AUTO,
828 		.fwnode = child,
829 		.data = &pdata,
830 		.size_data = sizeof(pdata),
831 	};
832 	struct platform_device *pdev;
833 
834 	pdev = platform_device_register_full(&pi);
835 	if (IS_ERR(pdev))
836 		return PTR_ERR(pdev);
837 
838 	return devm_add_action_or_reset(st->dev, axi_dac_child_remove, pdev);
839 }
840 
841 static const struct iio_backend_ops axi_dac_generic_ops = {
842 	.enable = axi_dac_enable,
843 	.disable = axi_dac_disable,
844 	.request_buffer = axi_dac_request_buffer,
845 	.free_buffer = axi_dac_free_buffer,
846 	.extend_chan_spec = axi_dac_extend_chan,
847 	.ext_info_set = axi_dac_ext_info_set,
848 	.ext_info_get = axi_dac_ext_info_get,
849 	.data_source_set = axi_dac_data_source_set,
850 	.set_sample_rate = axi_dac_set_sample_rate,
851 	.debugfs_reg_access = iio_backend_debugfs_ptr(axi_dac_reg_access),
852 };
853 
854 static const struct iio_backend_ops axi_ad3552r_ops = {
855 	.enable = axi_dac_enable,
856 	.disable = axi_dac_disable,
857 	.request_buffer = axi_dac_request_buffer,
858 	.free_buffer = axi_dac_free_buffer,
859 	.data_source_set = axi_dac_data_source_set,
860 	.data_source_get = axi_dac_data_source_get,
861 	.ddr_enable = axi_dac_ddr_enable,
862 	.ddr_disable = axi_dac_ddr_disable,
863 	.data_stream_enable = axi_dac_data_stream_enable,
864 	.data_stream_disable = axi_dac_data_stream_disable,
865 	.data_format_set = axi_dac_data_format_set,
866 	.data_transfer_addr = axi_dac_data_transfer_addr,
867 };
868 
869 static const struct iio_backend_info axi_dac_generic = {
870 	.name = "axi-dac",
871 	.ops = &axi_dac_generic_ops,
872 };
873 
874 static const struct iio_backend_info axi_ad3552r = {
875 	.name = "axi-ad3552r",
876 	.ops = &axi_ad3552r_ops,
877 };
878 
879 static const struct regmap_config axi_dac_regmap_config = {
880 	.val_bits = 32,
881 	.reg_bits = 32,
882 	.reg_stride = 4,
883 	.max_register = 0x0800,
884 };
885 
axi_dac_probe(struct platform_device * pdev)886 static int axi_dac_probe(struct platform_device *pdev)
887 {
888 	struct axi_dac_state *st;
889 	void __iomem *base;
890 	unsigned int ver;
891 	struct clk *clk;
892 	int ret;
893 
894 	st = devm_kzalloc(&pdev->dev, sizeof(*st), GFP_KERNEL);
895 	if (!st)
896 		return -ENOMEM;
897 
898 	st->info = device_get_match_data(&pdev->dev);
899 	if (!st->info)
900 		return -ENODEV;
901 	clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk");
902 	if (IS_ERR(clk)) {
903 		/* Backward compat., old fdt versions without clock-names. */
904 		clk = devm_clk_get_enabled(&pdev->dev, NULL);
905 		if (IS_ERR(clk))
906 			return dev_err_probe(&pdev->dev, PTR_ERR(clk),
907 					"failed to get clock\n");
908 	}
909 
910 	if (st->info->has_dac_clk) {
911 		struct clk *dac_clk;
912 
913 		dac_clk = devm_clk_get_enabled(&pdev->dev, "dac_clk");
914 		if (IS_ERR(dac_clk))
915 			return dev_err_probe(&pdev->dev, PTR_ERR(dac_clk),
916 					     "failed to get dac_clk clock\n");
917 
918 		/* We only care about the streaming mode rate */
919 		st->dac_clk_rate = clk_get_rate(dac_clk) / 2;
920 	}
921 
922 	base = devm_platform_ioremap_resource(pdev, 0);
923 	if (IS_ERR(base))
924 		return PTR_ERR(base);
925 
926 	st->dev = &pdev->dev;
927 	st->regmap = devm_regmap_init_mmio(&pdev->dev, base,
928 					   &axi_dac_regmap_config);
929 	if (IS_ERR(st->regmap))
930 		return dev_err_probe(&pdev->dev, PTR_ERR(st->regmap),
931 				     "failed to init register map\n");
932 
933 	/*
934 	 * Force disable the core. Up to the frontend to enable us. And we can
935 	 * still read/write registers...
936 	 */
937 	ret = regmap_write(st->regmap, AXI_DAC_RSTN_REG, 0);
938 	if (ret)
939 		return ret;
940 
941 	ret = regmap_read(st->regmap, ADI_AXI_REG_VERSION, &ver);
942 	if (ret)
943 		return ret;
944 
945 	if (ADI_AXI_PCORE_VER_MAJOR(ver) !=
946 		ADI_AXI_PCORE_VER_MAJOR(st->info->version)) {
947 		dev_err(&pdev->dev,
948 			"Major version mismatch. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
949 			ADI_AXI_PCORE_VER_MAJOR(st->info->version),
950 			ADI_AXI_PCORE_VER_MINOR(st->info->version),
951 			ADI_AXI_PCORE_VER_PATCH(st->info->version),
952 			ADI_AXI_PCORE_VER_MAJOR(ver),
953 			ADI_AXI_PCORE_VER_MINOR(ver),
954 			ADI_AXI_PCORE_VER_PATCH(ver));
955 		return -ENODEV;
956 	}
957 
958 	/* Let's get the core read only configuration */
959 	ret = regmap_read(st->regmap, AXI_DAC_CONFIG_REG, &st->reg_config);
960 	if (ret)
961 		return ret;
962 
963 	/*
964 	 * In some designs, setting the R1_MODE bit to 0 (which is the default
965 	 * value) causes all channels of the frontend to be routed to the same
966 	 * DMA (so they are sampled together). This is for things like
967 	 * Multiple-Input and Multiple-Output (MIMO). As most of the times we
968 	 * want independent channels let's override the core's default value and
969 	 * set the R1_MODE bit.
970 	 */
971 	ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
972 			      ADI_DAC_CNTRL_2_R1_MODE);
973 	if (ret)
974 		return ret;
975 
976 	mutex_init(&st->lock);
977 
978 	ret = devm_iio_backend_register(&pdev->dev, st->info->backend_info, st);
979 	if (ret)
980 		return dev_err_probe(&pdev->dev, ret,
981 				     "failed to register iio backend\n");
982 
983 	device_for_each_child_node_scoped(&pdev->dev, child) {
984 		int val;
985 
986 		if (!st->info->has_child_nodes)
987 			return dev_err_probe(&pdev->dev, -EINVAL,
988 					     "invalid fdt axi-dac compatible.");
989 
990 		/* Processing only reg 0 node */
991 		ret = fwnode_property_read_u32(child, "reg", &val);
992 		if (ret)
993 			return dev_err_probe(&pdev->dev, ret,
994 						"invalid reg property.");
995 		if (val != 0)
996 			return dev_err_probe(&pdev->dev, -EINVAL,
997 						"invalid node address.");
998 
999 		ret = axi_dac_create_platform_device(st, child);
1000 		if (ret)
1001 			return dev_err_probe(&pdev->dev, -EINVAL,
1002 						"cannot create device.");
1003 	}
1004 
1005 	dev_info(&pdev->dev, "AXI DAC IP core (%d.%.2d.%c) probed\n",
1006 		 ADI_AXI_PCORE_VER_MAJOR(ver),
1007 		 ADI_AXI_PCORE_VER_MINOR(ver),
1008 		 ADI_AXI_PCORE_VER_PATCH(ver));
1009 
1010 	return 0;
1011 }
1012 
1013 static const struct axi_dac_info dac_generic = {
1014 	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
1015 	.backend_info = &axi_dac_generic,
1016 };
1017 
1018 static const struct axi_dac_info dac_ad3552r = {
1019 	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
1020 	.backend_info = &axi_ad3552r,
1021 	.has_dac_clk = true,
1022 	.has_child_nodes = true,
1023 };
1024 
1025 static const struct of_device_id axi_dac_of_match[] = {
1026 	{ .compatible = "adi,axi-dac-9.1.b", .data = &dac_generic },
1027 	{ .compatible = "adi,axi-ad3552r", .data = &dac_ad3552r },
1028 	{ }
1029 };
1030 MODULE_DEVICE_TABLE(of, axi_dac_of_match);
1031 
1032 static struct platform_driver axi_dac_driver = {
1033 	.driver = {
1034 		.name = "adi-axi-dac",
1035 		.of_match_table = axi_dac_of_match,
1036 	},
1037 	.probe = axi_dac_probe,
1038 };
1039 module_platform_driver(axi_dac_driver);
1040 
1041 MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
1042 MODULE_DESCRIPTION("Analog Devices Generic AXI DAC IP core driver");
1043 MODULE_LICENSE("GPL");
1044 MODULE_IMPORT_NS("IIO_DMAENGINE_BUFFER");
1045 MODULE_IMPORT_NS("IIO_BACKEND");
1046