xref: /linux/drivers/iio/dac/adi-axi-dac.c (revision cb4eb6771c0f8fd1c52a8f6fdec7762fb087380a)
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 	int dac_clk_rate;
118 };
119 
axi_dac_enable(struct iio_backend * back)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 
axi_dac_disable(struct iio_backend * back)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 
axi_dac_request_buffer(struct iio_backend * back,struct iio_dev * indio_dev)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 
axi_dac_free_buffer(struct iio_backend * back,struct iio_buffer * buffer)168 static void axi_dac_free_buffer(struct iio_backend *back,
169 				struct iio_buffer *buffer)
170 {
171 	iio_dmaengine_buffer_teardown(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 
__axi_dac_frequency_get(struct axi_dac_state * st,unsigned int chan,unsigned int tone_2,unsigned int * freq)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 (chan > AXI_DAC_CHAN_CNTRL_MAX)
190 		return -EINVAL;
191 
192 	if (!st->dac_clk) {
193 		dev_err(st->dev, "Sampling rate is 0...\n");
194 		return -EINVAL;
195 	}
196 
197 	if (tone_2)
198 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan);
199 	else
200 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan);
201 
202 	ret = regmap_read(st->regmap, reg, &raw);
203 	if (ret)
204 		return ret;
205 
206 	raw = FIELD_GET(AXI_DAC_CHAN_CNTRL_2_FREQUENCY, raw);
207 	*freq = DIV_ROUND_CLOSEST_ULL(raw * st->dac_clk, BIT(16));
208 
209 	return 0;
210 }
211 
axi_dac_frequency_get(struct axi_dac_state * st,const struct iio_chan_spec * chan,char * buf,unsigned int tone_2)212 static int axi_dac_frequency_get(struct axi_dac_state *st,
213 				 const struct iio_chan_spec *chan, char *buf,
214 				 unsigned int tone_2)
215 {
216 	unsigned int freq;
217 	int ret;
218 
219 	scoped_guard(mutex, &st->lock) {
220 		ret = __axi_dac_frequency_get(st, chan->channel, tone_2, &freq);
221 		if (ret)
222 			return ret;
223 	}
224 
225 	return sysfs_emit(buf, "%u\n", freq);
226 }
227 
axi_dac_scale_get(struct axi_dac_state * st,const struct iio_chan_spec * chan,char * buf,unsigned int tone_2)228 static int axi_dac_scale_get(struct axi_dac_state *st,
229 			     const struct iio_chan_spec *chan, char *buf,
230 			     unsigned int tone_2)
231 {
232 	unsigned int scale, sign;
233 	int ret, vals[2];
234 	u32 reg, raw;
235 
236 	if (chan->channel > AXI_DAC_CHAN_CNTRL_MAX)
237 		return -EINVAL;
238 
239 	if (tone_2)
240 		reg = AXI_DAC_CHAN_CNTRL_3_REG(chan->channel);
241 	else
242 		reg = AXI_DAC_CHAN_CNTRL_1_REG(chan->channel);
243 
244 	ret = regmap_read(st->regmap, reg, &raw);
245 	if (ret)
246 		return ret;
247 
248 	sign = FIELD_GET(AXI_DAC_CHAN_CNTRL_3_SCALE_SIGN, raw);
249 	raw = FIELD_GET(AXI_DAC_CHAN_CNTRL_3_SCALE, raw);
250 	scale = DIV_ROUND_CLOSEST_ULL((u64)raw * MEGA,
251 				      AXI_DAC_CHAN_CNTRL_3_SCALE_INT);
252 
253 	vals[0] = scale / MEGA;
254 	vals[1] = scale % MEGA;
255 
256 	if (sign) {
257 		vals[0] *= -1;
258 		if (!vals[0])
259 			vals[1] *= -1;
260 	}
261 
262 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, ARRAY_SIZE(vals),
263 				vals);
264 }
265 
axi_dac_phase_get(struct axi_dac_state * st,const struct iio_chan_spec * chan,char * buf,unsigned int tone_2)266 static int axi_dac_phase_get(struct axi_dac_state *st,
267 			     const struct iio_chan_spec *chan, char *buf,
268 			     unsigned int tone_2)
269 {
270 	u32 reg, raw, phase;
271 	int ret, vals[2];
272 
273 	if (chan->channel > AXI_DAC_CHAN_CNTRL_MAX)
274 		return -EINVAL;
275 
276 	if (tone_2)
277 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan->channel);
278 	else
279 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan->channel);
280 
281 	ret = regmap_read(st->regmap, reg, &raw);
282 	if (ret)
283 		return ret;
284 
285 	raw = FIELD_GET(AXI_DAC_CHAN_CNTRL_2_PHASE, raw);
286 	phase = DIV_ROUND_CLOSEST_ULL((u64)raw * AXI_DAC_2_PI_MEGA, U16_MAX);
287 
288 	vals[0] = phase / MEGA;
289 	vals[1] = phase % MEGA;
290 
291 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, ARRAY_SIZE(vals),
292 				vals);
293 }
294 
__axi_dac_frequency_set(struct axi_dac_state * st,unsigned int chan,u64 sample_rate,unsigned int freq,unsigned int tone_2)295 static int __axi_dac_frequency_set(struct axi_dac_state *st, unsigned int chan,
296 				   u64 sample_rate, unsigned int freq,
297 				   unsigned int tone_2)
298 {
299 	u32 reg;
300 	u16 raw;
301 	int ret;
302 
303 	if (chan > AXI_DAC_CHAN_CNTRL_MAX)
304 		return -EINVAL;
305 
306 	if (!sample_rate || freq > sample_rate / 2) {
307 		dev_err(st->dev, "Invalid frequency(%u) dac_clk(%llu)\n",
308 			freq, sample_rate);
309 		return -EINVAL;
310 	}
311 
312 	if (tone_2)
313 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan);
314 	else
315 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan);
316 
317 	raw = DIV64_U64_ROUND_CLOSEST((u64)freq * BIT(16), sample_rate);
318 
319 	ret = regmap_update_bits(st->regmap, reg,
320 				 AXI_DAC_CHAN_CNTRL_2_FREQUENCY, raw);
321 	if (ret)
322 		return ret;
323 
324 	/* synchronize channels */
325 	return regmap_set_bits(st->regmap, AXI_DAC_CNTRL_1_REG,
326 			       AXI_DAC_CNTRL_1_SYNC);
327 }
328 
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)329 static int axi_dac_frequency_set(struct axi_dac_state *st,
330 				 const struct iio_chan_spec *chan,
331 				 const char *buf, size_t len, unsigned int tone_2)
332 {
333 	unsigned int freq;
334 	int ret;
335 
336 	ret = kstrtou32(buf, 10, &freq);
337 	if (ret)
338 		return ret;
339 
340 	guard(mutex)(&st->lock);
341 	ret = __axi_dac_frequency_set(st, chan->channel, st->dac_clk, freq,
342 				      tone_2);
343 	if (ret)
344 		return ret;
345 
346 	return len;
347 }
348 
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)349 static int axi_dac_scale_set(struct axi_dac_state *st,
350 			     const struct iio_chan_spec *chan,
351 			     const char *buf, size_t len, unsigned int tone_2)
352 {
353 	int integer, frac, scale;
354 	u32 raw = 0, reg;
355 	int ret;
356 
357 	if (chan->channel > AXI_DAC_CHAN_CNTRL_MAX)
358 		return -EINVAL;
359 
360 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &frac);
361 	if (ret)
362 		return ret;
363 
364 	scale = integer * MEGA + frac;
365 	if (scale <= -2 * (int)MEGA || scale >= 2 * (int)MEGA)
366 		return -EINVAL;
367 
368 	/*  format is 1.1.14 (sign, integer and fractional bits) */
369 	if (scale < 0) {
370 		raw = FIELD_PREP(AXI_DAC_CHAN_CNTRL_3_SCALE_SIGN, 1);
371 		scale *= -1;
372 	}
373 
374 	raw |= div_u64((u64)scale * AXI_DAC_CHAN_CNTRL_3_SCALE_INT, MEGA);
375 
376 	if (tone_2)
377 		reg = AXI_DAC_CHAN_CNTRL_3_REG(chan->channel);
378 	else
379 		reg = AXI_DAC_CHAN_CNTRL_1_REG(chan->channel);
380 
381 	guard(mutex)(&st->lock);
382 	ret = regmap_write(st->regmap, reg, raw);
383 	if (ret)
384 		return ret;
385 
386 	/* synchronize channels */
387 	ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_1_REG,
388 			      AXI_DAC_CNTRL_1_SYNC);
389 	if (ret)
390 		return ret;
391 
392 	return len;
393 }
394 
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)395 static int axi_dac_phase_set(struct axi_dac_state *st,
396 			     const struct iio_chan_spec *chan,
397 			     const char *buf, size_t len, unsigned int tone_2)
398 {
399 	int integer, frac, phase;
400 	u32 raw, reg;
401 	int ret;
402 
403 	if (chan->channel > AXI_DAC_CHAN_CNTRL_MAX)
404 		return -EINVAL;
405 
406 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &frac);
407 	if (ret)
408 		return ret;
409 
410 	phase = integer * MEGA + frac;
411 	if (phase < 0 || phase > AXI_DAC_2_PI_MEGA)
412 		return -EINVAL;
413 
414 	raw = DIV_ROUND_CLOSEST_ULL((u64)phase * U16_MAX, AXI_DAC_2_PI_MEGA);
415 
416 	if (tone_2)
417 		reg = AXI_DAC_CHAN_CNTRL_4_REG(chan->channel);
418 	else
419 		reg = AXI_DAC_CHAN_CNTRL_2_REG(chan->channel);
420 
421 	guard(mutex)(&st->lock);
422 	ret = regmap_update_bits(st->regmap, reg, AXI_DAC_CHAN_CNTRL_2_PHASE,
423 				 FIELD_PREP(AXI_DAC_CHAN_CNTRL_2_PHASE, raw));
424 	if (ret)
425 		return ret;
426 
427 	/* synchronize channels */
428 	ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_1_REG,
429 			      AXI_DAC_CNTRL_1_SYNC);
430 	if (ret)
431 		return ret;
432 
433 	return len;
434 }
435 
axi_dac_ext_info_set(struct iio_backend * back,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)436 static int axi_dac_ext_info_set(struct iio_backend *back, uintptr_t private,
437 				const struct iio_chan_spec *chan,
438 				const char *buf, size_t len)
439 {
440 	struct axi_dac_state *st = iio_backend_get_priv(back);
441 
442 	switch (private) {
443 	case AXI_DAC_FREQ_TONE_1:
444 	case AXI_DAC_FREQ_TONE_2:
445 		return axi_dac_frequency_set(st, chan, buf, len,
446 					     private == AXI_DAC_FREQ_TONE_2);
447 	case AXI_DAC_SCALE_TONE_1:
448 	case AXI_DAC_SCALE_TONE_2:
449 		return axi_dac_scale_set(st, chan, buf, len,
450 					 private == AXI_DAC_SCALE_TONE_2);
451 	case AXI_DAC_PHASE_TONE_1:
452 	case AXI_DAC_PHASE_TONE_2:
453 		return axi_dac_phase_set(st, chan, buf, len,
454 					 private == AXI_DAC_PHASE_TONE_2);
455 	default:
456 		return -EOPNOTSUPP;
457 	}
458 }
459 
axi_dac_ext_info_get(struct iio_backend * back,uintptr_t private,const struct iio_chan_spec * chan,char * buf)460 static int axi_dac_ext_info_get(struct iio_backend *back, uintptr_t private,
461 				const struct iio_chan_spec *chan, char *buf)
462 {
463 	struct axi_dac_state *st = iio_backend_get_priv(back);
464 
465 	switch (private) {
466 	case AXI_DAC_FREQ_TONE_1:
467 	case AXI_DAC_FREQ_TONE_2:
468 		return axi_dac_frequency_get(st, chan, buf,
469 					     private - AXI_DAC_FREQ_TONE_1);
470 	case AXI_DAC_SCALE_TONE_1:
471 	case AXI_DAC_SCALE_TONE_2:
472 		return axi_dac_scale_get(st, chan, buf,
473 					 private - AXI_DAC_SCALE_TONE_1);
474 	case AXI_DAC_PHASE_TONE_1:
475 	case AXI_DAC_PHASE_TONE_2:
476 		return axi_dac_phase_get(st, chan, buf,
477 					 private - AXI_DAC_PHASE_TONE_1);
478 	default:
479 		return -EOPNOTSUPP;
480 	}
481 }
482 
483 static const struct iio_chan_spec_ext_info axi_dac_ext_info[] = {
484 	IIO_BACKEND_EX_INFO("frequency0", IIO_SEPARATE, AXI_DAC_FREQ_TONE_1),
485 	IIO_BACKEND_EX_INFO("frequency1", IIO_SEPARATE, AXI_DAC_FREQ_TONE_2),
486 	IIO_BACKEND_EX_INFO("scale0", IIO_SEPARATE, AXI_DAC_SCALE_TONE_1),
487 	IIO_BACKEND_EX_INFO("scale1", IIO_SEPARATE, AXI_DAC_SCALE_TONE_2),
488 	IIO_BACKEND_EX_INFO("phase0", IIO_SEPARATE, AXI_DAC_PHASE_TONE_1),
489 	IIO_BACKEND_EX_INFO("phase1", IIO_SEPARATE, AXI_DAC_PHASE_TONE_2),
490 	{ }
491 };
492 
axi_dac_extend_chan(struct iio_backend * back,struct iio_chan_spec * chan)493 static int axi_dac_extend_chan(struct iio_backend *back,
494 			       struct iio_chan_spec *chan)
495 {
496 	struct axi_dac_state *st = iio_backend_get_priv(back);
497 
498 	if (chan->type != IIO_ALTVOLTAGE)
499 		return -EINVAL;
500 	if (st->reg_config & AXI_DAC_CONFIG_DDS_DISABLE)
501 		/* nothing to extend */
502 		return 0;
503 
504 	chan->ext_info = axi_dac_ext_info;
505 
506 	return 0;
507 }
508 
axi_dac_data_source_set(struct iio_backend * back,unsigned int chan,enum iio_backend_data_source data)509 static int axi_dac_data_source_set(struct iio_backend *back, unsigned int chan,
510 				   enum iio_backend_data_source data)
511 {
512 	struct axi_dac_state *st = iio_backend_get_priv(back);
513 
514 	if (chan > AXI_DAC_CHAN_CNTRL_MAX)
515 		return -EINVAL;
516 
517 	switch (data) {
518 	case IIO_BACKEND_INTERNAL_CONTINUOUS_WAVE:
519 		return regmap_update_bits(st->regmap,
520 					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
521 					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
522 					  AXI_DAC_DATA_INTERNAL_TONE);
523 	case IIO_BACKEND_EXTERNAL:
524 		return regmap_update_bits(st->regmap,
525 					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
526 					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
527 					  AXI_DAC_DATA_DMA);
528 	case IIO_BACKEND_INTERNAL_RAMP_16BIT:
529 		return regmap_update_bits(st->regmap,
530 					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
531 					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
532 					  AXI_DAC_DATA_INTERNAL_RAMP_16BIT);
533 	default:
534 		return -EINVAL;
535 	}
536 }
537 
axi_dac_data_source_get(struct iio_backend * back,unsigned int chan,enum iio_backend_data_source * data)538 static int axi_dac_data_source_get(struct iio_backend *back, unsigned int chan,
539 				   enum iio_backend_data_source *data)
540 {
541 	struct axi_dac_state *st = iio_backend_get_priv(back);
542 	int ret;
543 	u32 val;
544 
545 	if (chan > AXI_DAC_CHAN_CNTRL_MAX)
546 		return -EINVAL;
547 
548 	ret = regmap_read(st->regmap, AXI_DAC_CHAN_CNTRL_7_REG(chan), &val);
549 	if (ret)
550 		return ret;
551 
552 	switch (val) {
553 	case AXI_DAC_DATA_INTERNAL_TONE:
554 		*data = IIO_BACKEND_INTERNAL_CONTINUOUS_WAVE;
555 		return 0;
556 	case AXI_DAC_DATA_DMA:
557 		*data = IIO_BACKEND_EXTERNAL;
558 		return 0;
559 	case AXI_DAC_DATA_INTERNAL_RAMP_16BIT:
560 		*data = IIO_BACKEND_INTERNAL_RAMP_16BIT;
561 		return 0;
562 	default:
563 		return -EIO;
564 	}
565 }
566 
axi_dac_set_sample_rate(struct iio_backend * back,unsigned int chan,u64 sample_rate)567 static int axi_dac_set_sample_rate(struct iio_backend *back, unsigned int chan,
568 				   u64 sample_rate)
569 {
570 	struct axi_dac_state *st = iio_backend_get_priv(back);
571 	unsigned int freq;
572 	int ret, tone;
573 
574 	if (chan > AXI_DAC_CHAN_CNTRL_MAX)
575 		return -EINVAL;
576 	if (!sample_rate)
577 		return -EINVAL;
578 	if (st->reg_config & AXI_DAC_CONFIG_DDS_DISABLE)
579 		/* sample_rate has no meaning if DDS is disabled */
580 		return 0;
581 
582 	guard(mutex)(&st->lock);
583 	/*
584 	 * If dac_clk is 0 then this must be the first time we're being notified
585 	 * about the interface sample rate. Hence, just update our internal
586 	 * variable and bail... If it's not 0, then we get the current DDS
587 	 * frequency (for the old rate) and update the registers for the new
588 	 * sample rate.
589 	 */
590 	if (!st->dac_clk) {
591 		st->dac_clk = sample_rate;
592 		return 0;
593 	}
594 
595 	for (tone = 0; tone <= AXI_DAC_FREQ_TONE_2; tone++) {
596 		ret = __axi_dac_frequency_get(st, chan, tone, &freq);
597 		if (ret)
598 			return ret;
599 
600 		ret = __axi_dac_frequency_set(st, chan, sample_rate, tone, freq);
601 		if (ret)
602 			return ret;
603 	}
604 
605 	st->dac_clk = sample_rate;
606 
607 	return 0;
608 }
609 
axi_dac_reg_access(struct iio_backend * back,unsigned int reg,unsigned int writeval,unsigned int * readval)610 static int axi_dac_reg_access(struct iio_backend *back, unsigned int reg,
611 			      unsigned int writeval, unsigned int *readval)
612 {
613 	struct axi_dac_state *st = iio_backend_get_priv(back);
614 
615 	if (readval)
616 		return regmap_read(st->regmap, reg, readval);
617 
618 	return regmap_write(st->regmap, reg, writeval);
619 }
620 
axi_dac_ddr_enable(struct iio_backend * back)621 static int axi_dac_ddr_enable(struct iio_backend *back)
622 {
623 	struct axi_dac_state *st = iio_backend_get_priv(back);
624 
625 	return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
626 				 AXI_DAC_CNTRL_2_SDR_DDR_N);
627 }
628 
axi_dac_ddr_disable(struct iio_backend * back)629 static int axi_dac_ddr_disable(struct iio_backend *back)
630 {
631 	struct axi_dac_state *st = iio_backend_get_priv(back);
632 
633 	return regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
634 			       AXI_DAC_CNTRL_2_SDR_DDR_N);
635 }
636 
axi_dac_wait_bus_free(struct axi_dac_state * st)637 static int axi_dac_wait_bus_free(struct axi_dac_state *st)
638 {
639 	u32 val;
640 	int ret;
641 
642 	ret = regmap_read_poll_timeout(st->regmap, AXI_DAC_UI_STATUS_REG, val,
643 		FIELD_GET(AXI_DAC_UI_STATUS_IF_BUSY, val) == 0, 10,
644 		100 * KILO);
645 	if (ret == -ETIMEDOUT)
646 		dev_err(st->dev, "AXI bus timeout\n");
647 
648 	return ret;
649 }
650 
axi_dac_data_stream_enable(struct iio_backend * back)651 static int axi_dac_data_stream_enable(struct iio_backend *back)
652 {
653 	struct axi_dac_state *st = iio_backend_get_priv(back);
654 	int ret;
655 
656 	ret = axi_dac_wait_bus_free(st);
657 	if (ret)
658 		return ret;
659 
660 	return regmap_set_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
661 			       AXI_DAC_CUSTOM_CTRL_STREAM_ENABLE);
662 }
663 
axi_dac_data_stream_disable(struct iio_backend * back)664 static int axi_dac_data_stream_disable(struct iio_backend *back)
665 {
666 	struct axi_dac_state *st = iio_backend_get_priv(back);
667 
668 	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
669 				 AXI_DAC_CUSTOM_CTRL_STREAM_ENABLE);
670 }
671 
axi_dac_data_transfer_addr(struct iio_backend * back,u32 address)672 static int axi_dac_data_transfer_addr(struct iio_backend *back, u32 address)
673 {
674 	struct axi_dac_state *st = iio_backend_get_priv(back);
675 
676 	if (address > FIELD_MAX(AXI_DAC_CUSTOM_CTRL_ADDRESS))
677 		return -EINVAL;
678 
679 	/*
680 	 * Sample register address, when the DAC is configured, or stream
681 	 * start address when the FSM is in stream state.
682 	 */
683 	return regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
684 				  AXI_DAC_CUSTOM_CTRL_ADDRESS,
685 				  FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS,
686 				  address));
687 }
688 
axi_dac_data_format_set(struct iio_backend * back,unsigned int ch,const struct iio_backend_data_fmt * data)689 static int axi_dac_data_format_set(struct iio_backend *back, unsigned int ch,
690 				   const struct iio_backend_data_fmt *data)
691 {
692 	struct axi_dac_state *st = iio_backend_get_priv(back);
693 
694 	switch (data->type) {
695 	case IIO_BACKEND_DATA_UNSIGNED:
696 		return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
697 					 AXI_DAC_CNTRL_2_UNSIGNED_DATA);
698 	default:
699 		return -EINVAL;
700 	}
701 }
702 
__axi_dac_bus_reg_write(struct iio_backend * back,u32 reg,u32 val,size_t data_size)703 static int __axi_dac_bus_reg_write(struct iio_backend *back, u32 reg,
704 				 u32 val, size_t data_size)
705 {
706 	struct axi_dac_state *st = iio_backend_get_priv(back);
707 	int ret;
708 	u32 ival;
709 
710 	/*
711 	 * Both AXI_DAC_CNTRL_2_REG and AXI_DAC_CUSTOM_WR_REG need to know
712 	 * the data size. So keeping data size control here only,
713 	 * since data size is mandatory for the current transfer.
714 	 * DDR state handled separately by specific backend calls,
715 	 * generally all raw register writes are SDR.
716 	 */
717 	if (data_size == sizeof(u16))
718 		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_16, val);
719 	else
720 		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_8, val);
721 
722 	ret = regmap_write(st->regmap, AXI_DAC_CUSTOM_WR_REG, ival);
723 	if (ret)
724 		return ret;
725 
726 	if (data_size == sizeof(u8))
727 		ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
728 				      AXI_DAC_CNTRL_2_SYMB_8B);
729 	else
730 		ret = regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
731 					AXI_DAC_CNTRL_2_SYMB_8B);
732 	if (ret)
733 		return ret;
734 
735 	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
736 				 AXI_DAC_CUSTOM_CTRL_ADDRESS,
737 				 FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS, reg));
738 	if (ret)
739 		return ret;
740 
741 	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
742 				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA,
743 				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
744 	if (ret)
745 		return ret;
746 
747 	ret = axi_dac_wait_bus_free(st);
748 	if (ret)
749 		return ret;
750 
751 	/* Cleaning always AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA */
752 	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
753 				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
754 }
755 
axi_dac_bus_reg_write(struct iio_backend * back,u32 reg,u32 val,size_t data_size)756 static int axi_dac_bus_reg_write(struct iio_backend *back, u32 reg,
757 					u32 val, size_t data_size)
758 {
759 	struct axi_dac_state *st = iio_backend_get_priv(back);
760 
761 	guard(mutex)(&st->lock);
762 	return __axi_dac_bus_reg_write(back, reg, val, data_size);
763 }
764 
axi_dac_bus_reg_read(struct iio_backend * back,u32 reg,u32 * val,size_t data_size)765 static int axi_dac_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val,
766 				size_t data_size)
767 {
768 	struct axi_dac_state *st = iio_backend_get_priv(back);
769 	int ret;
770 
771 	guard(mutex)(&st->lock);
772 
773 	/*
774 	 * SPI, we write with read flag, then we read just at the AXI
775 	 * io address space to get data read.
776 	 */
777 	ret = __axi_dac_bus_reg_write(back, AXI_DAC_RD_ADDR(reg), 0,
778 				      data_size);
779 	if (ret)
780 		return ret;
781 
782 	ret = axi_dac_wait_bus_free(st);
783 	if (ret)
784 		return ret;
785 
786 	return regmap_read(st->regmap, AXI_DAC_CUSTOM_RD_REG, val);
787 }
788 
axi_dac_bus_set_io_mode(struct iio_backend * back,enum ad3552r_io_mode mode)789 static int axi_dac_bus_set_io_mode(struct iio_backend *back,
790 				   enum ad3552r_io_mode mode)
791 {
792 	struct axi_dac_state *st = iio_backend_get_priv(back);
793 	int ret;
794 
795 	if (mode > AD3552R_IO_MODE_QSPI)
796 		return -EINVAL;
797 
798 	guard(mutex)(&st->lock);
799 
800 	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
801 			AXI_DAC_CUSTOM_CTRL_MULTI_IO_MODE,
802 			FIELD_PREP(AXI_DAC_CUSTOM_CTRL_MULTI_IO_MODE, mode));
803 	if (ret)
804 		return ret;
805 
806 	return axi_dac_wait_bus_free(st);
807 }
808 
axi_dac_child_remove(void * data)809 static void axi_dac_child_remove(void *data)
810 {
811 	platform_device_unregister(data);
812 }
813 
axi_dac_create_platform_device(struct axi_dac_state * st,struct fwnode_handle * child)814 static int axi_dac_create_platform_device(struct axi_dac_state *st,
815 					  struct fwnode_handle *child)
816 {
817 	struct ad3552r_hs_platform_data pdata = {
818 		.bus_reg_read = axi_dac_bus_reg_read,
819 		.bus_reg_write = axi_dac_bus_reg_write,
820 		.bus_set_io_mode = axi_dac_bus_set_io_mode,
821 		.bus_sample_data_clock_hz = st->dac_clk_rate,
822 	};
823 	struct platform_device_info pi = {
824 		.parent = st->dev,
825 		.name = fwnode_get_name(child),
826 		.id = PLATFORM_DEVID_AUTO,
827 		.fwnode = child,
828 		.data = &pdata,
829 		.size_data = sizeof(pdata),
830 	};
831 	struct platform_device *pdev;
832 
833 	pdev = platform_device_register_full(&pi);
834 	if (IS_ERR(pdev))
835 		return PTR_ERR(pdev);
836 
837 	return devm_add_action_or_reset(st->dev, axi_dac_child_remove, pdev);
838 }
839 
840 static const struct iio_backend_ops axi_dac_generic_ops = {
841 	.enable = axi_dac_enable,
842 	.disable = axi_dac_disable,
843 	.request_buffer = axi_dac_request_buffer,
844 	.free_buffer = axi_dac_free_buffer,
845 	.extend_chan_spec = axi_dac_extend_chan,
846 	.ext_info_set = axi_dac_ext_info_set,
847 	.ext_info_get = axi_dac_ext_info_get,
848 	.data_source_set = axi_dac_data_source_set,
849 	.set_sample_rate = axi_dac_set_sample_rate,
850 	.debugfs_reg_access = iio_backend_debugfs_ptr(axi_dac_reg_access),
851 };
852 
853 static const struct iio_backend_ops axi_ad3552r_ops = {
854 	.enable = axi_dac_enable,
855 	.disable = axi_dac_disable,
856 	.request_buffer = axi_dac_request_buffer,
857 	.free_buffer = axi_dac_free_buffer,
858 	.data_source_set = axi_dac_data_source_set,
859 	.data_source_get = axi_dac_data_source_get,
860 	.ddr_enable = axi_dac_ddr_enable,
861 	.ddr_disable = axi_dac_ddr_disable,
862 	.data_stream_enable = axi_dac_data_stream_enable,
863 	.data_stream_disable = axi_dac_data_stream_disable,
864 	.data_format_set = axi_dac_data_format_set,
865 	.data_transfer_addr = axi_dac_data_transfer_addr,
866 };
867 
868 static const struct iio_backend_info axi_dac_generic = {
869 	.name = "axi-dac",
870 	.ops = &axi_dac_generic_ops,
871 	.caps = IIO_BACKEND_CAP_BUFFER | IIO_BACKEND_CAP_ENABLE,
872 };
873 
874 static const struct iio_backend_info axi_ad3552r = {
875 	.name = "axi-ad3552r",
876 	.ops = &axi_ad3552r_ops,
877 	.caps = IIO_BACKEND_CAP_BUFFER | IIO_BACKEND_CAP_ENABLE,
878 };
879 
880 static const struct regmap_config axi_dac_regmap_config = {
881 	.val_bits = 32,
882 	.reg_bits = 32,
883 	.reg_stride = 4,
884 	.max_register = 0x0800,
885 };
886 
axi_dac_probe(struct platform_device * pdev)887 static int axi_dac_probe(struct platform_device *pdev)
888 {
889 	struct device *dev = &pdev->dev;
890 	struct axi_dac_state *st;
891 	void __iomem *base;
892 	unsigned int ver;
893 	struct clk *clk;
894 	int ret;
895 
896 	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
897 	if (!st)
898 		return -ENOMEM;
899 
900 	st->info = device_get_match_data(dev);
901 	if (!st->info)
902 		return -ENODEV;
903 	clk = devm_clk_get_enabled(dev, "s_axi_aclk");
904 	if (IS_ERR(clk)) {
905 		/* Backward compat., old fdt versions without clock-names. */
906 		clk = devm_clk_get_enabled(dev, NULL);
907 		if (IS_ERR(clk))
908 			return dev_err_probe(dev, PTR_ERR(clk),
909 					     "failed to get clock\n");
910 	}
911 
912 	if (st->info->has_dac_clk) {
913 		struct clk *dac_clk;
914 
915 		dac_clk = devm_clk_get_enabled(dev, "dac_clk");
916 		if (IS_ERR(dac_clk))
917 			return dev_err_probe(dev, PTR_ERR(dac_clk),
918 					     "failed to get dac_clk clock\n");
919 
920 		/* We only care about the streaming mode rate */
921 		st->dac_clk_rate = clk_get_rate(dac_clk) / 2;
922 	}
923 
924 	base = devm_platform_ioremap_resource(pdev, 0);
925 	if (IS_ERR(base))
926 		return PTR_ERR(base);
927 
928 	st->dev = dev;
929 	st->regmap = devm_regmap_init_mmio(dev, base, &axi_dac_regmap_config);
930 	if (IS_ERR(st->regmap))
931 		return dev_err_probe(dev, PTR_ERR(st->regmap),
932 				     "failed to init register map\n");
933 
934 	/*
935 	 * Force disable the core. Up to the frontend to enable us. And we can
936 	 * still read/write registers...
937 	 */
938 	ret = regmap_write(st->regmap, AXI_DAC_RSTN_REG, 0);
939 	if (ret)
940 		return ret;
941 
942 	ret = regmap_read(st->regmap, ADI_AXI_REG_VERSION, &ver);
943 	if (ret)
944 		return ret;
945 
946 	if (ADI_AXI_PCORE_VER_MAJOR(ver) != ADI_AXI_PCORE_VER_MAJOR(st->info->version))
947 		return dev_err_probe(dev, -ENODEV,
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 
956 	/* Let's get the core read only configuration */
957 	ret = regmap_read(st->regmap, AXI_DAC_CONFIG_REG, &st->reg_config);
958 	if (ret)
959 		return ret;
960 
961 	/*
962 	 * In some designs, setting the R1_MODE bit to 0 (which is the default
963 	 * value) causes all channels of the frontend to be routed to the same
964 	 * DMA (so they are sampled together). This is for things like
965 	 * Multiple-Input and Multiple-Output (MIMO). As most of the times we
966 	 * want independent channels let's override the core's default value and
967 	 * set the R1_MODE bit.
968 	 */
969 	ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
970 			      ADI_DAC_CNTRL_2_R1_MODE);
971 	if (ret)
972 		return ret;
973 
974 	mutex_init(&st->lock);
975 
976 	ret = devm_iio_backend_register(dev, st->info->backend_info, st);
977 	if (ret)
978 		return dev_err_probe(dev, ret,
979 				     "failed to register iio backend\n");
980 
981 	device_for_each_child_node_scoped(dev, child) {
982 		int val;
983 
984 		if (!st->info->has_child_nodes)
985 			return dev_err_probe(dev, -EINVAL,
986 					     "invalid fdt axi-dac compatible.");
987 
988 		/* Processing only reg 0 node */
989 		ret = fwnode_property_read_u32(child, "reg", &val);
990 		if (ret)
991 			return dev_err_probe(dev, ret, "invalid reg property.");
992 		if (val != 0)
993 			return dev_err_probe(dev, -EINVAL,
994 					     "invalid node address.");
995 
996 		ret = axi_dac_create_platform_device(st, child);
997 		if (ret)
998 			return dev_err_probe(dev, -EINVAL,
999 					     "cannot create device.");
1000 	}
1001 
1002 	dev_info(dev, "AXI DAC IP core (%d.%.2d.%c) probed\n",
1003 		 ADI_AXI_PCORE_VER_MAJOR(ver),
1004 		 ADI_AXI_PCORE_VER_MINOR(ver),
1005 		 ADI_AXI_PCORE_VER_PATCH(ver));
1006 
1007 	return 0;
1008 }
1009 
1010 static const struct axi_dac_info dac_generic = {
1011 	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
1012 	.backend_info = &axi_dac_generic,
1013 };
1014 
1015 static const struct axi_dac_info dac_ad3552r = {
1016 	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
1017 	.backend_info = &axi_ad3552r,
1018 	.has_dac_clk = true,
1019 	.has_child_nodes = true,
1020 };
1021 
1022 static const struct of_device_id axi_dac_of_match[] = {
1023 	{ .compatible = "adi,axi-dac-9.1.b", .data = &dac_generic },
1024 	{ .compatible = "adi,axi-ad3552r", .data = &dac_ad3552r },
1025 	{ }
1026 };
1027 MODULE_DEVICE_TABLE(of, axi_dac_of_match);
1028 
1029 static struct platform_driver axi_dac_driver = {
1030 	.driver = {
1031 		.name = "adi-axi-dac",
1032 		.of_match_table = axi_dac_of_match,
1033 	},
1034 	.probe = axi_dac_probe,
1035 };
1036 module_platform_driver(axi_dac_driver);
1037 
1038 MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
1039 MODULE_DESCRIPTION("Analog Devices Generic AXI DAC IP core driver");
1040 MODULE_LICENSE("GPL");
1041 MODULE_IMPORT_NS("IIO_DMAENGINE_BUFFER");
1042 MODULE_IMPORT_NS("IIO_BACKEND");
1043