xref: /openbmc/linux/drivers/iio/dac/ad5755.c (revision e65e175b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AD5755, AD5755-1, AD5757, AD5735, AD5737 Digital to analog converters driver
4  *
5  * Copyright 2012 Analog Devices Inc.
6  */
7 
8 #include <linux/device.h>
9 #include <linux/err.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/spi/spi.h>
13 #include <linux/slab.h>
14 #include <linux/sysfs.h>
15 #include <linux/delay.h>
16 #include <linux/property.h>
17 
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 
21 #define AD5755_NUM_CHANNELS 4
22 
23 #define AD5755_ADDR(x)			((x) << 16)
24 
25 #define AD5755_WRITE_REG_DATA(chan)	(chan)
26 #define AD5755_WRITE_REG_GAIN(chan)	(0x08 | (chan))
27 #define AD5755_WRITE_REG_OFFSET(chan)	(0x10 | (chan))
28 #define AD5755_WRITE_REG_CTRL(chan)	(0x1c | (chan))
29 
30 #define AD5755_READ_REG_DATA(chan)	(chan)
31 #define AD5755_READ_REG_CTRL(chan)	(0x4 | (chan))
32 #define AD5755_READ_REG_GAIN(chan)	(0x8 | (chan))
33 #define AD5755_READ_REG_OFFSET(chan)	(0xc | (chan))
34 #define AD5755_READ_REG_CLEAR(chan)	(0x10 | (chan))
35 #define AD5755_READ_REG_SLEW(chan)	(0x14 | (chan))
36 #define AD5755_READ_REG_STATUS		0x18
37 #define AD5755_READ_REG_MAIN		0x19
38 #define AD5755_READ_REG_DC_DC		0x1a
39 
40 #define AD5755_CTRL_REG_SLEW	0x0
41 #define AD5755_CTRL_REG_MAIN	0x1
42 #define AD5755_CTRL_REG_DAC	0x2
43 #define AD5755_CTRL_REG_DC_DC	0x3
44 #define AD5755_CTRL_REG_SW	0x4
45 
46 #define AD5755_READ_FLAG 0x800000
47 
48 #define AD5755_NOOP 0x1CE000
49 
50 #define AD5755_DAC_INT_EN			BIT(8)
51 #define AD5755_DAC_CLR_EN			BIT(7)
52 #define AD5755_DAC_OUT_EN			BIT(6)
53 #define AD5755_DAC_INT_CURRENT_SENSE_RESISTOR	BIT(5)
54 #define AD5755_DAC_DC_DC_EN			BIT(4)
55 #define AD5755_DAC_VOLTAGE_OVERRANGE_EN		BIT(3)
56 
57 #define AD5755_DC_DC_MAXV			0
58 #define AD5755_DC_DC_FREQ_SHIFT			2
59 #define AD5755_DC_DC_PHASE_SHIFT		4
60 #define AD5755_EXT_DC_DC_COMP_RES		BIT(6)
61 
62 #define AD5755_SLEW_STEP_SIZE_SHIFT		0
63 #define AD5755_SLEW_RATE_SHIFT			3
64 #define AD5755_SLEW_ENABLE			BIT(12)
65 
66 enum ad5755_mode {
67 	AD5755_MODE_VOLTAGE_0V_5V		= 0,
68 	AD5755_MODE_VOLTAGE_0V_10V		= 1,
69 	AD5755_MODE_VOLTAGE_PLUSMINUS_5V	= 2,
70 	AD5755_MODE_VOLTAGE_PLUSMINUS_10V	= 3,
71 	AD5755_MODE_CURRENT_4mA_20mA		= 4,
72 	AD5755_MODE_CURRENT_0mA_20mA		= 5,
73 	AD5755_MODE_CURRENT_0mA_24mA		= 6,
74 };
75 
76 enum ad5755_dc_dc_phase {
77 	AD5755_DC_DC_PHASE_ALL_SAME_EDGE		= 0,
78 	AD5755_DC_DC_PHASE_A_B_SAME_EDGE_C_D_OPP_EDGE	= 1,
79 	AD5755_DC_DC_PHASE_A_C_SAME_EDGE_B_D_OPP_EDGE	= 2,
80 	AD5755_DC_DC_PHASE_90_DEGREE			= 3,
81 };
82 
83 enum ad5755_dc_dc_freq {
84 	AD5755_DC_DC_FREQ_250kHZ = 0,
85 	AD5755_DC_DC_FREQ_410kHZ = 1,
86 	AD5755_DC_DC_FREQ_650kHZ = 2,
87 };
88 
89 enum ad5755_dc_dc_maxv {
90 	AD5755_DC_DC_MAXV_23V	= 0,
91 	AD5755_DC_DC_MAXV_24V5	= 1,
92 	AD5755_DC_DC_MAXV_27V	= 2,
93 	AD5755_DC_DC_MAXV_29V5	= 3,
94 };
95 
96 enum ad5755_slew_rate {
97 	AD5755_SLEW_RATE_64k	= 0,
98 	AD5755_SLEW_RATE_32k	= 1,
99 	AD5755_SLEW_RATE_16k	= 2,
100 	AD5755_SLEW_RATE_8k	= 3,
101 	AD5755_SLEW_RATE_4k	= 4,
102 	AD5755_SLEW_RATE_2k	= 5,
103 	AD5755_SLEW_RATE_1k	= 6,
104 	AD5755_SLEW_RATE_500	= 7,
105 	AD5755_SLEW_RATE_250	= 8,
106 	AD5755_SLEW_RATE_125	= 9,
107 	AD5755_SLEW_RATE_64	= 10,
108 	AD5755_SLEW_RATE_32	= 11,
109 	AD5755_SLEW_RATE_16	= 12,
110 	AD5755_SLEW_RATE_8	= 13,
111 	AD5755_SLEW_RATE_4	= 14,
112 	AD5755_SLEW_RATE_0_5	= 15,
113 };
114 
115 enum ad5755_slew_step_size {
116 	AD5755_SLEW_STEP_SIZE_1 = 0,
117 	AD5755_SLEW_STEP_SIZE_2 = 1,
118 	AD5755_SLEW_STEP_SIZE_4 = 2,
119 	AD5755_SLEW_STEP_SIZE_8 = 3,
120 	AD5755_SLEW_STEP_SIZE_16 = 4,
121 	AD5755_SLEW_STEP_SIZE_32 = 5,
122 	AD5755_SLEW_STEP_SIZE_64 = 6,
123 	AD5755_SLEW_STEP_SIZE_128 = 7,
124 	AD5755_SLEW_STEP_SIZE_256 = 8,
125 };
126 
127 /**
128  * struct ad5755_platform_data - AD5755 DAC driver platform data
129  * @ext_dc_dc_compenstation_resistor: Whether an external DC-DC converter
130  * compensation register is used.
131  * @dc_dc_phase: DC-DC converter phase.
132  * @dc_dc_freq: DC-DC converter frequency.
133  * @dc_dc_maxv: DC-DC maximum allowed boost voltage.
134  * @dac: Per DAC instance parameters.
135  * @dac.mode: The mode to be used for the DAC output.
136  * @dac.ext_current_sense_resistor: Whether an external current sense resistor
137  * is used.
138  * @dac.enable_voltage_overrange: Whether to enable 20% voltage output overrange.
139  * @dac.slew.enable: Whether to enable digital slew.
140  * @dac.slew.rate: Slew rate of the digital slew.
141  * @dac.slew.step_size: Slew step size of the digital slew.
142  **/
143 struct ad5755_platform_data {
144 	bool ext_dc_dc_compenstation_resistor;
145 	enum ad5755_dc_dc_phase dc_dc_phase;
146 	enum ad5755_dc_dc_freq dc_dc_freq;
147 	enum ad5755_dc_dc_maxv dc_dc_maxv;
148 
149 	struct {
150 		enum ad5755_mode mode;
151 		bool ext_current_sense_resistor;
152 		bool enable_voltage_overrange;
153 		struct {
154 			bool enable;
155 			enum ad5755_slew_rate rate;
156 			enum ad5755_slew_step_size step_size;
157 		} slew;
158 	} dac[4];
159 };
160 
161 /**
162  * struct ad5755_chip_info - chip specific information
163  * @channel_template:	channel specification
164  * @calib_shift:	shift for the calibration data registers
165  * @has_voltage_out:	whether the chip has voltage outputs
166  */
167 struct ad5755_chip_info {
168 	const struct iio_chan_spec channel_template;
169 	unsigned int calib_shift;
170 	bool has_voltage_out;
171 };
172 
173 /**
174  * struct ad5755_state - driver instance specific data
175  * @spi:	spi device the driver is attached to
176  * @chip_info:	chip model specific constants, available modes etc
177  * @pwr_down:	bitmask which contains  hether a channel is powered down or not
178  * @ctrl:	software shadow of the channel ctrl registers
179  * @channels:	iio channel spec for the device
180  * @lock:	lock to protect the data buffer during SPI ops
181  * @data:	spi transfer buffers
182  */
183 struct ad5755_state {
184 	struct spi_device		*spi;
185 	const struct ad5755_chip_info	*chip_info;
186 	unsigned int			pwr_down;
187 	unsigned int			ctrl[AD5755_NUM_CHANNELS];
188 	struct iio_chan_spec		channels[AD5755_NUM_CHANNELS];
189 	struct mutex			lock;
190 
191 	/*
192 	 * DMA (thus cache coherency maintenance) may require the
193 	 * transfer buffers to live in their own cache lines.
194 	 */
195 
196 	union {
197 		__be32 d32;
198 		u8 d8[4];
199 	} data[2] __aligned(IIO_DMA_MINALIGN);
200 };
201 
202 enum ad5755_type {
203 	ID_AD5755,
204 	ID_AD5757,
205 	ID_AD5735,
206 	ID_AD5737,
207 };
208 
209 static const int ad5755_dcdc_freq_table[][2] = {
210 	{ 250000, AD5755_DC_DC_FREQ_250kHZ },
211 	{ 410000, AD5755_DC_DC_FREQ_410kHZ },
212 	{ 650000, AD5755_DC_DC_FREQ_650kHZ }
213 };
214 
215 static const int ad5755_dcdc_maxv_table[][2] = {
216 	{ 23000000, AD5755_DC_DC_MAXV_23V },
217 	{ 24500000, AD5755_DC_DC_MAXV_24V5 },
218 	{ 27000000, AD5755_DC_DC_MAXV_27V },
219 	{ 29500000, AD5755_DC_DC_MAXV_29V5 },
220 };
221 
222 static const int ad5755_slew_rate_table[][2] = {
223 	{ 64000, AD5755_SLEW_RATE_64k },
224 	{ 32000, AD5755_SLEW_RATE_32k },
225 	{ 16000, AD5755_SLEW_RATE_16k },
226 	{ 8000, AD5755_SLEW_RATE_8k },
227 	{ 4000, AD5755_SLEW_RATE_4k },
228 	{ 2000, AD5755_SLEW_RATE_2k },
229 	{ 1000, AD5755_SLEW_RATE_1k },
230 	{ 500, AD5755_SLEW_RATE_500 },
231 	{ 250, AD5755_SLEW_RATE_250 },
232 	{ 125, AD5755_SLEW_RATE_125 },
233 	{ 64, AD5755_SLEW_RATE_64 },
234 	{ 32, AD5755_SLEW_RATE_32 },
235 	{ 16, AD5755_SLEW_RATE_16 },
236 	{ 8, AD5755_SLEW_RATE_8 },
237 	{ 4, AD5755_SLEW_RATE_4 },
238 	{ 0, AD5755_SLEW_RATE_0_5 },
239 };
240 
241 static const int ad5755_slew_step_table[][2] = {
242 	{ 256, AD5755_SLEW_STEP_SIZE_256 },
243 	{ 128, AD5755_SLEW_STEP_SIZE_128 },
244 	{ 64, AD5755_SLEW_STEP_SIZE_64 },
245 	{ 32, AD5755_SLEW_STEP_SIZE_32 },
246 	{ 16, AD5755_SLEW_STEP_SIZE_16 },
247 	{ 4, AD5755_SLEW_STEP_SIZE_4 },
248 	{ 2, AD5755_SLEW_STEP_SIZE_2 },
249 	{ 1, AD5755_SLEW_STEP_SIZE_1 },
250 };
251 
252 static int ad5755_write_unlocked(struct iio_dev *indio_dev,
253 	unsigned int reg, unsigned int val)
254 {
255 	struct ad5755_state *st = iio_priv(indio_dev);
256 
257 	st->data[0].d32 = cpu_to_be32((reg << 16) | val);
258 
259 	return spi_write(st->spi, &st->data[0].d8[1], 3);
260 }
261 
262 static int ad5755_write_ctrl_unlocked(struct iio_dev *indio_dev,
263 	unsigned int channel, unsigned int reg, unsigned int val)
264 {
265 	return ad5755_write_unlocked(indio_dev,
266 		AD5755_WRITE_REG_CTRL(channel), (reg << 13) | val);
267 }
268 
269 static int ad5755_write(struct iio_dev *indio_dev, unsigned int reg,
270 	unsigned int val)
271 {
272 	struct ad5755_state *st = iio_priv(indio_dev);
273 	int ret;
274 
275 	mutex_lock(&st->lock);
276 	ret = ad5755_write_unlocked(indio_dev, reg, val);
277 	mutex_unlock(&st->lock);
278 
279 	return ret;
280 }
281 
282 static int ad5755_write_ctrl(struct iio_dev *indio_dev, unsigned int channel,
283 	unsigned int reg, unsigned int val)
284 {
285 	struct ad5755_state *st = iio_priv(indio_dev);
286 	int ret;
287 
288 	mutex_lock(&st->lock);
289 	ret = ad5755_write_ctrl_unlocked(indio_dev, channel, reg, val);
290 	mutex_unlock(&st->lock);
291 
292 	return ret;
293 }
294 
295 static int ad5755_read(struct iio_dev *indio_dev, unsigned int addr)
296 {
297 	struct ad5755_state *st = iio_priv(indio_dev);
298 	int ret;
299 	struct spi_transfer t[] = {
300 		{
301 			.tx_buf = &st->data[0].d8[1],
302 			.len = 3,
303 			.cs_change = 1,
304 		}, {
305 			.tx_buf = &st->data[1].d8[1],
306 			.rx_buf = &st->data[1].d8[1],
307 			.len = 3,
308 		},
309 	};
310 
311 	mutex_lock(&st->lock);
312 
313 	st->data[0].d32 = cpu_to_be32(AD5755_READ_FLAG | (addr << 16));
314 	st->data[1].d32 = cpu_to_be32(AD5755_NOOP);
315 
316 	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
317 	if (ret >= 0)
318 		ret = be32_to_cpu(st->data[1].d32) & 0xffff;
319 
320 	mutex_unlock(&st->lock);
321 
322 	return ret;
323 }
324 
325 static int ad5755_update_dac_ctrl(struct iio_dev *indio_dev,
326 	unsigned int channel, unsigned int set, unsigned int clr)
327 {
328 	struct ad5755_state *st = iio_priv(indio_dev);
329 	int ret;
330 
331 	st->ctrl[channel] |= set;
332 	st->ctrl[channel] &= ~clr;
333 
334 	ret = ad5755_write_ctrl_unlocked(indio_dev, channel,
335 		AD5755_CTRL_REG_DAC, st->ctrl[channel]);
336 
337 	return ret;
338 }
339 
340 static int ad5755_set_channel_pwr_down(struct iio_dev *indio_dev,
341 	unsigned int channel, bool pwr_down)
342 {
343 	struct ad5755_state *st = iio_priv(indio_dev);
344 	unsigned int mask = BIT(channel);
345 
346 	mutex_lock(&st->lock);
347 
348 	if ((bool)(st->pwr_down & mask) == pwr_down)
349 		goto out_unlock;
350 
351 	if (!pwr_down) {
352 		st->pwr_down &= ~mask;
353 		ad5755_update_dac_ctrl(indio_dev, channel,
354 			AD5755_DAC_INT_EN | AD5755_DAC_DC_DC_EN, 0);
355 		udelay(200);
356 		ad5755_update_dac_ctrl(indio_dev, channel,
357 			AD5755_DAC_OUT_EN, 0);
358 	} else {
359 		st->pwr_down |= mask;
360 		ad5755_update_dac_ctrl(indio_dev, channel,
361 			0, AD5755_DAC_INT_EN | AD5755_DAC_OUT_EN |
362 				AD5755_DAC_DC_DC_EN);
363 	}
364 
365 out_unlock:
366 	mutex_unlock(&st->lock);
367 
368 	return 0;
369 }
370 
371 static const int ad5755_min_max_table[][2] = {
372 	[AD5755_MODE_VOLTAGE_0V_5V] = { 0, 5000 },
373 	[AD5755_MODE_VOLTAGE_0V_10V] = { 0, 10000 },
374 	[AD5755_MODE_VOLTAGE_PLUSMINUS_5V] = { -5000, 5000 },
375 	[AD5755_MODE_VOLTAGE_PLUSMINUS_10V] = { -10000, 10000 },
376 	[AD5755_MODE_CURRENT_4mA_20mA] = { 4, 20 },
377 	[AD5755_MODE_CURRENT_0mA_20mA] = { 0, 20 },
378 	[AD5755_MODE_CURRENT_0mA_24mA] = { 0, 24 },
379 };
380 
381 static void ad5755_get_min_max(struct ad5755_state *st,
382 	struct iio_chan_spec const *chan, int *min, int *max)
383 {
384 	enum ad5755_mode mode = st->ctrl[chan->channel] & 7;
385 	*min = ad5755_min_max_table[mode][0];
386 	*max = ad5755_min_max_table[mode][1];
387 }
388 
389 static inline int ad5755_get_offset(struct ad5755_state *st,
390 	struct iio_chan_spec const *chan)
391 {
392 	int min, max;
393 
394 	ad5755_get_min_max(st, chan, &min, &max);
395 	return (min * (1 << chan->scan_type.realbits)) / (max - min);
396 }
397 
398 static int ad5755_chan_reg_info(struct ad5755_state *st,
399 	struct iio_chan_spec const *chan, long info, bool write,
400 	unsigned int *reg, unsigned int *shift, unsigned int *offset)
401 {
402 	switch (info) {
403 	case IIO_CHAN_INFO_RAW:
404 		if (write)
405 			*reg = AD5755_WRITE_REG_DATA(chan->address);
406 		else
407 			*reg = AD5755_READ_REG_DATA(chan->address);
408 		*shift = chan->scan_type.shift;
409 		*offset = 0;
410 		break;
411 	case IIO_CHAN_INFO_CALIBBIAS:
412 		if (write)
413 			*reg = AD5755_WRITE_REG_OFFSET(chan->address);
414 		else
415 			*reg = AD5755_READ_REG_OFFSET(chan->address);
416 		*shift = st->chip_info->calib_shift;
417 		*offset = 32768;
418 		break;
419 	case IIO_CHAN_INFO_CALIBSCALE:
420 		if (write)
421 			*reg =  AD5755_WRITE_REG_GAIN(chan->address);
422 		else
423 			*reg =  AD5755_READ_REG_GAIN(chan->address);
424 		*shift = st->chip_info->calib_shift;
425 		*offset = 0;
426 		break;
427 	default:
428 		return -EINVAL;
429 	}
430 
431 	return 0;
432 }
433 
434 static int ad5755_read_raw(struct iio_dev *indio_dev,
435 	const struct iio_chan_spec *chan, int *val, int *val2, long info)
436 {
437 	struct ad5755_state *st = iio_priv(indio_dev);
438 	unsigned int reg, shift, offset;
439 	int min, max;
440 	int ret;
441 
442 	switch (info) {
443 	case IIO_CHAN_INFO_SCALE:
444 		ad5755_get_min_max(st, chan, &min, &max);
445 		*val = max - min;
446 		*val2 = chan->scan_type.realbits;
447 		return IIO_VAL_FRACTIONAL_LOG2;
448 	case IIO_CHAN_INFO_OFFSET:
449 		*val = ad5755_get_offset(st, chan);
450 		return IIO_VAL_INT;
451 	default:
452 		ret = ad5755_chan_reg_info(st, chan, info, false,
453 						&reg, &shift, &offset);
454 		if (ret)
455 			return ret;
456 
457 		ret = ad5755_read(indio_dev, reg);
458 		if (ret < 0)
459 			return ret;
460 
461 		*val = (ret - offset) >> shift;
462 
463 		return IIO_VAL_INT;
464 	}
465 
466 	return -EINVAL;
467 }
468 
469 static int ad5755_write_raw(struct iio_dev *indio_dev,
470 	const struct iio_chan_spec *chan, int val, int val2, long info)
471 {
472 	struct ad5755_state *st = iio_priv(indio_dev);
473 	unsigned int shift, reg, offset;
474 	int ret;
475 
476 	ret = ad5755_chan_reg_info(st, chan, info, true,
477 					&reg, &shift, &offset);
478 	if (ret)
479 		return ret;
480 
481 	val <<= shift;
482 	val += offset;
483 
484 	if (val < 0 || val > 0xffff)
485 		return -EINVAL;
486 
487 	return ad5755_write(indio_dev, reg, val);
488 }
489 
490 static ssize_t ad5755_read_powerdown(struct iio_dev *indio_dev, uintptr_t priv,
491 	const struct iio_chan_spec *chan, char *buf)
492 {
493 	struct ad5755_state *st = iio_priv(indio_dev);
494 
495 	return sysfs_emit(buf, "%d\n",
496 			  (bool)(st->pwr_down & (1 << chan->channel)));
497 }
498 
499 static ssize_t ad5755_write_powerdown(struct iio_dev *indio_dev, uintptr_t priv,
500 	struct iio_chan_spec const *chan, const char *buf, size_t len)
501 {
502 	bool pwr_down;
503 	int ret;
504 
505 	ret = kstrtobool(buf, &pwr_down);
506 	if (ret)
507 		return ret;
508 
509 	ret = ad5755_set_channel_pwr_down(indio_dev, chan->channel, pwr_down);
510 	return ret ? ret : len;
511 }
512 
513 static const struct iio_info ad5755_info = {
514 	.read_raw = ad5755_read_raw,
515 	.write_raw = ad5755_write_raw,
516 };
517 
518 static const struct iio_chan_spec_ext_info ad5755_ext_info[] = {
519 	{
520 		.name = "powerdown",
521 		.read = ad5755_read_powerdown,
522 		.write = ad5755_write_powerdown,
523 		.shared = IIO_SEPARATE,
524 	},
525 	{ },
526 };
527 
528 #define AD5755_CHANNEL(_bits) {					\
529 	.indexed = 1,						\
530 	.output = 1,						\
531 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
532 		BIT(IIO_CHAN_INFO_SCALE) |			\
533 		BIT(IIO_CHAN_INFO_OFFSET) |			\
534 		BIT(IIO_CHAN_INFO_CALIBSCALE) |			\
535 		BIT(IIO_CHAN_INFO_CALIBBIAS),			\
536 	.scan_type = {						\
537 		.sign = 'u',					\
538 		.realbits = (_bits),				\
539 		.storagebits = 16,				\
540 		.shift = 16 - (_bits),				\
541 	},							\
542 	.ext_info = ad5755_ext_info,				\
543 }
544 
545 static const struct ad5755_chip_info ad5755_chip_info_tbl[] = {
546 	[ID_AD5735] = {
547 		.channel_template = AD5755_CHANNEL(14),
548 		.has_voltage_out = true,
549 		.calib_shift = 4,
550 	},
551 	[ID_AD5737] = {
552 		.channel_template = AD5755_CHANNEL(14),
553 		.has_voltage_out = false,
554 		.calib_shift = 4,
555 	},
556 	[ID_AD5755] = {
557 		.channel_template = AD5755_CHANNEL(16),
558 		.has_voltage_out = true,
559 		.calib_shift = 0,
560 	},
561 	[ID_AD5757] = {
562 		.channel_template = AD5755_CHANNEL(16),
563 		.has_voltage_out = false,
564 		.calib_shift = 0,
565 	},
566 };
567 
568 static bool ad5755_is_valid_mode(struct ad5755_state *st, enum ad5755_mode mode)
569 {
570 	switch (mode) {
571 	case AD5755_MODE_VOLTAGE_0V_5V:
572 	case AD5755_MODE_VOLTAGE_0V_10V:
573 	case AD5755_MODE_VOLTAGE_PLUSMINUS_5V:
574 	case AD5755_MODE_VOLTAGE_PLUSMINUS_10V:
575 		return st->chip_info->has_voltage_out;
576 	case AD5755_MODE_CURRENT_4mA_20mA:
577 	case AD5755_MODE_CURRENT_0mA_20mA:
578 	case AD5755_MODE_CURRENT_0mA_24mA:
579 		return true;
580 	default:
581 		return false;
582 	}
583 }
584 
585 static int ad5755_setup_pdata(struct iio_dev *indio_dev,
586 			      const struct ad5755_platform_data *pdata)
587 {
588 	struct ad5755_state *st = iio_priv(indio_dev);
589 	unsigned int val;
590 	unsigned int i;
591 	int ret;
592 
593 	if (pdata->dc_dc_phase > AD5755_DC_DC_PHASE_90_DEGREE ||
594 		pdata->dc_dc_freq > AD5755_DC_DC_FREQ_650kHZ ||
595 		pdata->dc_dc_maxv > AD5755_DC_DC_MAXV_29V5)
596 		return -EINVAL;
597 
598 	val = pdata->dc_dc_maxv << AD5755_DC_DC_MAXV;
599 	val |= pdata->dc_dc_freq << AD5755_DC_DC_FREQ_SHIFT;
600 	val |= pdata->dc_dc_phase << AD5755_DC_DC_PHASE_SHIFT;
601 	if (pdata->ext_dc_dc_compenstation_resistor)
602 		val |= AD5755_EXT_DC_DC_COMP_RES;
603 
604 	ret = ad5755_write_ctrl(indio_dev, 0, AD5755_CTRL_REG_DC_DC, val);
605 	if (ret < 0)
606 		return ret;
607 
608 	for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) {
609 		val = pdata->dac[i].slew.step_size <<
610 			AD5755_SLEW_STEP_SIZE_SHIFT;
611 		val |= pdata->dac[i].slew.rate <<
612 			AD5755_SLEW_RATE_SHIFT;
613 		if (pdata->dac[i].slew.enable)
614 			val |= AD5755_SLEW_ENABLE;
615 
616 		ret = ad5755_write_ctrl(indio_dev, i,
617 					AD5755_CTRL_REG_SLEW, val);
618 		if (ret < 0)
619 			return ret;
620 	}
621 
622 	for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) {
623 		if (!ad5755_is_valid_mode(st, pdata->dac[i].mode))
624 			return -EINVAL;
625 
626 		val = 0;
627 		if (!pdata->dac[i].ext_current_sense_resistor)
628 			val |= AD5755_DAC_INT_CURRENT_SENSE_RESISTOR;
629 		if (pdata->dac[i].enable_voltage_overrange)
630 			val |= AD5755_DAC_VOLTAGE_OVERRANGE_EN;
631 		val |= pdata->dac[i].mode;
632 
633 		ret = ad5755_update_dac_ctrl(indio_dev, i, val, 0);
634 		if (ret < 0)
635 			return ret;
636 	}
637 
638 	return 0;
639 }
640 
641 static bool ad5755_is_voltage_mode(enum ad5755_mode mode)
642 {
643 	switch (mode) {
644 	case AD5755_MODE_VOLTAGE_0V_5V:
645 	case AD5755_MODE_VOLTAGE_0V_10V:
646 	case AD5755_MODE_VOLTAGE_PLUSMINUS_5V:
647 	case AD5755_MODE_VOLTAGE_PLUSMINUS_10V:
648 		return true;
649 	default:
650 		return false;
651 	}
652 }
653 
654 static int ad5755_init_channels(struct iio_dev *indio_dev,
655 				const struct ad5755_platform_data *pdata)
656 {
657 	struct ad5755_state *st = iio_priv(indio_dev);
658 	struct iio_chan_spec *channels = st->channels;
659 	unsigned int i;
660 
661 	for (i = 0; i < AD5755_NUM_CHANNELS; ++i) {
662 		channels[i] = st->chip_info->channel_template;
663 		channels[i].channel = i;
664 		channels[i].address = i;
665 		if (pdata && ad5755_is_voltage_mode(pdata->dac[i].mode))
666 			channels[i].type = IIO_VOLTAGE;
667 		else
668 			channels[i].type = IIO_CURRENT;
669 	}
670 
671 	indio_dev->channels = channels;
672 
673 	return 0;
674 }
675 
676 #define AD5755_DEFAULT_DAC_PDATA { \
677 		.mode = AD5755_MODE_CURRENT_4mA_20mA, \
678 		.ext_current_sense_resistor = true, \
679 		.enable_voltage_overrange = false, \
680 		.slew = { \
681 			.enable = false, \
682 			.rate = AD5755_SLEW_RATE_64k, \
683 			.step_size = AD5755_SLEW_STEP_SIZE_1, \
684 		}, \
685 	}
686 
687 static const struct ad5755_platform_data ad5755_default_pdata = {
688 	.ext_dc_dc_compenstation_resistor = false,
689 	.dc_dc_phase = AD5755_DC_DC_PHASE_ALL_SAME_EDGE,
690 	.dc_dc_freq = AD5755_DC_DC_FREQ_410kHZ,
691 	.dc_dc_maxv = AD5755_DC_DC_MAXV_23V,
692 	.dac = {
693 		[0] = AD5755_DEFAULT_DAC_PDATA,
694 		[1] = AD5755_DEFAULT_DAC_PDATA,
695 		[2] = AD5755_DEFAULT_DAC_PDATA,
696 		[3] = AD5755_DEFAULT_DAC_PDATA,
697 	},
698 };
699 
700 static struct ad5755_platform_data *ad5755_parse_fw(struct device *dev)
701 {
702 	struct fwnode_handle *pp;
703 	struct ad5755_platform_data *pdata;
704 	unsigned int tmp;
705 	unsigned int tmparray[3];
706 	int devnr, i;
707 
708 	if (!dev_fwnode(dev))
709 		return NULL;
710 
711 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
712 	if (!pdata)
713 		return NULL;
714 
715 	pdata->ext_dc_dc_compenstation_resistor =
716 	    device_property_read_bool(dev, "adi,ext-dc-dc-compenstation-resistor");
717 
718 	pdata->dc_dc_phase = AD5755_DC_DC_PHASE_ALL_SAME_EDGE;
719 	device_property_read_u32(dev, "adi,dc-dc-phase", &pdata->dc_dc_phase);
720 
721 	pdata->dc_dc_freq = AD5755_DC_DC_FREQ_410kHZ;
722 	if (!device_property_read_u32(dev, "adi,dc-dc-freq-hz", &tmp)) {
723 		for (i = 0; i < ARRAY_SIZE(ad5755_dcdc_freq_table); i++) {
724 			if (tmp == ad5755_dcdc_freq_table[i][0]) {
725 				pdata->dc_dc_freq = ad5755_dcdc_freq_table[i][1];
726 				break;
727 			}
728 		}
729 
730 		if (i == ARRAY_SIZE(ad5755_dcdc_freq_table))
731 			dev_err(dev,
732 				"adi,dc-dc-freq out of range selecting 410kHz\n");
733 	}
734 
735 	pdata->dc_dc_maxv = AD5755_DC_DC_MAXV_23V;
736 	if (!device_property_read_u32(dev, "adi,dc-dc-max-microvolt", &tmp)) {
737 		for (i = 0; i < ARRAY_SIZE(ad5755_dcdc_maxv_table); i++) {
738 			if (tmp == ad5755_dcdc_maxv_table[i][0]) {
739 				pdata->dc_dc_maxv = ad5755_dcdc_maxv_table[i][1];
740 				break;
741 			}
742 		}
743 		if (i == ARRAY_SIZE(ad5755_dcdc_maxv_table))
744 				dev_err(dev,
745 					"adi,dc-dc-maxv out of range selecting 23V\n");
746 	}
747 
748 	devnr = 0;
749 	device_for_each_child_node(dev, pp) {
750 		if (devnr >= AD5755_NUM_CHANNELS) {
751 			dev_err(dev,
752 				"There are too many channels defined in DT\n");
753 			goto error_out;
754 		}
755 
756 		pdata->dac[devnr].mode = AD5755_MODE_CURRENT_4mA_20mA;
757 		fwnode_property_read_u32(pp, "adi,mode", &pdata->dac[devnr].mode);
758 
759 		pdata->dac[devnr].ext_current_sense_resistor =
760 		    fwnode_property_read_bool(pp, "adi,ext-current-sense-resistor");
761 
762 		pdata->dac[devnr].enable_voltage_overrange =
763 		    fwnode_property_read_bool(pp, "adi,enable-voltage-overrange");
764 
765 		if (!fwnode_property_read_u32_array(pp, "adi,slew", tmparray, 3)) {
766 			pdata->dac[devnr].slew.enable = tmparray[0];
767 
768 			pdata->dac[devnr].slew.rate = AD5755_SLEW_RATE_64k;
769 			for (i = 0; i < ARRAY_SIZE(ad5755_slew_rate_table); i++) {
770 				if (tmparray[1] == ad5755_slew_rate_table[i][0]) {
771 					pdata->dac[devnr].slew.rate =
772 						ad5755_slew_rate_table[i][1];
773 					break;
774 				}
775 			}
776 			if (i == ARRAY_SIZE(ad5755_slew_rate_table))
777 				dev_err(dev,
778 					"channel %d slew rate out of range selecting 64kHz\n",
779 					devnr);
780 
781 			pdata->dac[devnr].slew.step_size = AD5755_SLEW_STEP_SIZE_1;
782 			for (i = 0; i < ARRAY_SIZE(ad5755_slew_step_table); i++) {
783 				if (tmparray[2] == ad5755_slew_step_table[i][0]) {
784 					pdata->dac[devnr].slew.step_size =
785 						ad5755_slew_step_table[i][1];
786 					break;
787 				}
788 			}
789 			if (i == ARRAY_SIZE(ad5755_slew_step_table))
790 				dev_err(dev,
791 					"channel %d slew step size out of range selecting 1 LSB\n",
792 					devnr);
793 		} else {
794 			pdata->dac[devnr].slew.enable = false;
795 			pdata->dac[devnr].slew.rate = AD5755_SLEW_RATE_64k;
796 			pdata->dac[devnr].slew.step_size =
797 			    AD5755_SLEW_STEP_SIZE_1;
798 		}
799 		devnr++;
800 	}
801 
802 	return pdata;
803 
804  error_out:
805 	devm_kfree(dev, pdata);
806 	return NULL;
807 }
808 
809 static int ad5755_probe(struct spi_device *spi)
810 {
811 	enum ad5755_type type = spi_get_device_id(spi)->driver_data;
812 	const struct ad5755_platform_data *pdata;
813 	struct iio_dev *indio_dev;
814 	struct ad5755_state *st;
815 	int ret;
816 
817 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
818 	if (indio_dev == NULL) {
819 		dev_err(&spi->dev, "Failed to allocate iio device\n");
820 		return  -ENOMEM;
821 	}
822 
823 	st = iio_priv(indio_dev);
824 	spi_set_drvdata(spi, indio_dev);
825 
826 	st->chip_info = &ad5755_chip_info_tbl[type];
827 	st->spi = spi;
828 	st->pwr_down = 0xf;
829 
830 	indio_dev->name = spi_get_device_id(spi)->name;
831 	indio_dev->info = &ad5755_info;
832 	indio_dev->modes = INDIO_DIRECT_MODE;
833 	indio_dev->num_channels = AD5755_NUM_CHANNELS;
834 
835 	mutex_init(&st->lock);
836 
837 
838 	pdata = ad5755_parse_fw(&spi->dev);
839 	if (!pdata) {
840 		dev_warn(&spi->dev, "no firmware provided parameters? using default\n");
841 		pdata = &ad5755_default_pdata;
842 	}
843 
844 	ret = ad5755_init_channels(indio_dev, pdata);
845 	if (ret)
846 		return ret;
847 
848 	ret = ad5755_setup_pdata(indio_dev, pdata);
849 	if (ret)
850 		return ret;
851 
852 	return devm_iio_device_register(&spi->dev, indio_dev);
853 }
854 
855 static const struct spi_device_id ad5755_id[] = {
856 	{ "ad5755", ID_AD5755 },
857 	{ "ad5755-1", ID_AD5755 },
858 	{ "ad5757", ID_AD5757 },
859 	{ "ad5735", ID_AD5735 },
860 	{ "ad5737", ID_AD5737 },
861 	{}
862 };
863 MODULE_DEVICE_TABLE(spi, ad5755_id);
864 
865 static const struct of_device_id ad5755_of_match[] = {
866 	{ .compatible = "adi,ad5755" },
867 	{ .compatible = "adi,ad5755-1" },
868 	{ .compatible = "adi,ad5757" },
869 	{ .compatible = "adi,ad5735" },
870 	{ .compatible = "adi,ad5737" },
871 	{ }
872 };
873 MODULE_DEVICE_TABLE(of, ad5755_of_match);
874 
875 static struct spi_driver ad5755_driver = {
876 	.driver = {
877 		.name = "ad5755",
878 	},
879 	.probe = ad5755_probe,
880 	.id_table = ad5755_id,
881 };
882 module_spi_driver(ad5755_driver);
883 
884 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
885 MODULE_DESCRIPTION("Analog Devices AD5755/55-1/57/35/37 DAC");
886 MODULE_LICENSE("GPL v2");
887