xref: /kernel/linux/linux-5.10/drivers/iio/dac/ad5758.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * AD5758 Digital to analog converters driver
4 *
5 * Copyright 2018 Analog Devices Inc.
6 *
7 * TODO: Currently CRC is not supported in this driver
8 */
9#include <linux/bsearch.h>
10#include <linux/delay.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/property.h>
14#include <linux/of.h>
15#include <linux/of_device.h>
16#include <linux/spi/spi.h>
17#include <linux/gpio/consumer.h>
18
19#include <linux/iio/iio.h>
20#include <linux/iio/sysfs.h>
21
22/* AD5758 registers definition */
23#define AD5758_NOP				0x00
24#define AD5758_DAC_INPUT			0x01
25#define AD5758_DAC_OUTPUT			0x02
26#define AD5758_CLEAR_CODE			0x03
27#define AD5758_USER_GAIN			0x04
28#define AD5758_USER_OFFSET			0x05
29#define AD5758_DAC_CONFIG			0x06
30#define AD5758_SW_LDAC				0x07
31#define AD5758_KEY				0x08
32#define AD5758_GP_CONFIG1			0x09
33#define AD5758_GP_CONFIG2			0x0A
34#define AD5758_DCDC_CONFIG1			0x0B
35#define AD5758_DCDC_CONFIG2			0x0C
36#define AD5758_WDT_CONFIG			0x0F
37#define AD5758_DIGITAL_DIAG_CONFIG		0x10
38#define AD5758_ADC_CONFIG			0x11
39#define AD5758_FAULT_PIN_CONFIG			0x12
40#define AD5758_TWO_STAGE_READBACK_SELECT	0x13
41#define AD5758_DIGITAL_DIAG_RESULTS		0x14
42#define AD5758_ANALOG_DIAG_RESULTS		0x15
43#define AD5758_STATUS				0x16
44#define AD5758_CHIP_ID				0x17
45#define AD5758_FREQ_MONITOR			0x18
46#define AD5758_DEVICE_ID_0			0x19
47#define AD5758_DEVICE_ID_1			0x1A
48#define AD5758_DEVICE_ID_2			0x1B
49#define AD5758_DEVICE_ID_3			0x1C
50
51/* AD5758_DAC_CONFIG */
52#define AD5758_DAC_CONFIG_RANGE_MSK		GENMASK(3, 0)
53#define AD5758_DAC_CONFIG_RANGE_MODE(x)		(((x) & 0xF) << 0)
54#define AD5758_DAC_CONFIG_INT_EN_MSK		BIT(5)
55#define AD5758_DAC_CONFIG_INT_EN_MODE(x)	(((x) & 0x1) << 5)
56#define AD5758_DAC_CONFIG_OUT_EN_MSK		BIT(6)
57#define AD5758_DAC_CONFIG_OUT_EN_MODE(x)	(((x) & 0x1) << 6)
58#define AD5758_DAC_CONFIG_SR_EN_MSK		BIT(8)
59#define AD5758_DAC_CONFIG_SR_EN_MODE(x)		(((x) & 0x1) << 8)
60#define AD5758_DAC_CONFIG_SR_CLOCK_MSK		GENMASK(12, 9)
61#define AD5758_DAC_CONFIG_SR_CLOCK_MODE(x)	(((x) & 0xF) << 9)
62#define AD5758_DAC_CONFIG_SR_STEP_MSK		GENMASK(15, 13)
63#define AD5758_DAC_CONFIG_SR_STEP_MODE(x)	(((x) & 0x7) << 13)
64
65/* AD5758_KEY */
66#define AD5758_KEY_CODE_RESET_1			0x15FA
67#define AD5758_KEY_CODE_RESET_2			0xAF51
68#define AD5758_KEY_CODE_SINGLE_ADC_CONV		0x1ADC
69#define AD5758_KEY_CODE_RESET_WDT		0x0D06
70#define AD5758_KEY_CODE_CALIB_MEM_REFRESH	0xFCBA
71
72/* AD5758_DCDC_CONFIG1 */
73#define AD5758_DCDC_CONFIG1_DCDC_VPROG_MSK	GENMASK(4, 0)
74#define AD5758_DCDC_CONFIG1_DCDC_VPROG_MODE(x)	(((x) & 0x1F) << 0)
75#define AD5758_DCDC_CONFIG1_DCDC_MODE_MSK	GENMASK(6, 5)
76#define AD5758_DCDC_CONFIG1_DCDC_MODE_MODE(x)	(((x) & 0x3) << 5)
77
78/* AD5758_DCDC_CONFIG2 */
79#define AD5758_DCDC_CONFIG2_ILIMIT_MSK		GENMASK(3, 1)
80#define AD5758_DCDC_CONFIG2_ILIMIT_MODE(x)	(((x) & 0x7) << 1)
81#define AD5758_DCDC_CONFIG2_INTR_SAT_3WI_MSK	BIT(11)
82#define AD5758_DCDC_CONFIG2_BUSY_3WI_MSK	BIT(12)
83
84/* AD5758_DIGITAL_DIAG_RESULTS */
85#define AD5758_CAL_MEM_UNREFRESHED_MSK		BIT(15)
86
87/* AD5758_ADC_CONFIG */
88#define AD5758_ADC_CONFIG_PPC_BUF_EN(x)		(((x) & 0x1) << 11)
89#define AD5758_ADC_CONFIG_PPC_BUF_MSK		BIT(11)
90
91#define AD5758_WR_FLAG_MSK(x)		(0x80 | ((x) & 0x1F))
92
93#define AD5758_FULL_SCALE_MICRO	65535000000ULL
94
95struct ad5758_range {
96	int reg;
97	int min;
98	int max;
99};
100
101/**
102 * struct ad5758_state - driver instance specific data
103 * @spi:	spi_device
104 * @lock:	mutex lock
105 * @gpio_reset:	gpio descriptor for the reset line
106 * @out_range:	struct which stores the output range
107 * @dc_dc_mode:	variable which stores the mode of operation
108 * @dc_dc_ilim:	variable which stores the dc-to-dc converter current limit
109 * @slew_time:	variable which stores the target slew time
110 * @pwr_down:	variable which contains whether a channel is powered down or not
111 * @d32:	spi transfer buffers
112 */
113struct ad5758_state {
114	struct spi_device *spi;
115	struct mutex lock;
116	struct gpio_desc *gpio_reset;
117	struct ad5758_range out_range;
118	unsigned int dc_dc_mode;
119	unsigned int dc_dc_ilim;
120	unsigned int slew_time;
121	bool pwr_down;
122	__be32 d32[3];
123};
124
125/*
126 * Output ranges corresponding to bits [3:0] from DAC_CONFIG register
127 * 0000: 0 V to 5 V voltage range
128 * 0001: 0 V to 10 V voltage range
129 * 0010: ±5 V voltage range
130 * 0011: ±10 V voltage range
131 * 1000: 0 mA to 20 mA current range
132 * 1001: 0 mA to 24 mA current range
133 * 1010: 4 mA to 20 mA current range
134 * 1011: ±20 mA current range
135 * 1100: ±24 mA current range
136 * 1101: -1 mA to +22 mA current range
137 */
138enum ad5758_output_range {
139	AD5758_RANGE_0V_5V,
140	AD5758_RANGE_0V_10V,
141	AD5758_RANGE_PLUSMINUS_5V,
142	AD5758_RANGE_PLUSMINUS_10V,
143	AD5758_RANGE_0mA_20mA = 8,
144	AD5758_RANGE_0mA_24mA,
145	AD5758_RANGE_4mA_24mA,
146	AD5758_RANGE_PLUSMINUS_20mA,
147	AD5758_RANGE_PLUSMINUS_24mA,
148	AD5758_RANGE_MINUS_1mA_PLUS_22mA,
149};
150
151enum ad5758_dc_dc_mode {
152	AD5758_DCDC_MODE_POWER_OFF,
153	AD5758_DCDC_MODE_DPC_CURRENT,
154	AD5758_DCDC_MODE_DPC_VOLTAGE,
155	AD5758_DCDC_MODE_PPC_CURRENT,
156};
157
158static const struct ad5758_range ad5758_voltage_range[] = {
159	{ AD5758_RANGE_0V_5V, 0, 5000000 },
160	{ AD5758_RANGE_0V_10V, 0, 10000000 },
161	{ AD5758_RANGE_PLUSMINUS_5V, -5000000, 5000000 },
162	{ AD5758_RANGE_PLUSMINUS_10V, -10000000, 10000000 }
163};
164
165static const struct ad5758_range ad5758_current_range[] = {
166	{ AD5758_RANGE_0mA_20mA, 0, 20000},
167	{ AD5758_RANGE_0mA_24mA, 0, 24000 },
168	{ AD5758_RANGE_4mA_24mA, 4, 24000 },
169	{ AD5758_RANGE_PLUSMINUS_20mA, -20000, 20000 },
170	{ AD5758_RANGE_PLUSMINUS_24mA, -24000, 24000 },
171	{ AD5758_RANGE_MINUS_1mA_PLUS_22mA, -1000, 22000 },
172};
173
174static const int ad5758_sr_clk[16] = {
175	240000, 200000, 150000, 128000, 64000, 32000, 16000, 8000, 4000, 2000,
176	1000, 512, 256, 128, 64, 16
177};
178
179static const int ad5758_sr_step[8] = {
180	4, 12, 64, 120, 256, 500, 1820, 2048
181};
182
183static const int ad5758_dc_dc_ilim[6] = {
184	150000, 200000, 250000, 300000, 350000, 400000
185};
186
187static int ad5758_spi_reg_read(struct ad5758_state *st, unsigned int addr)
188{
189	struct spi_transfer t[] = {
190		{
191			.tx_buf = &st->d32[0],
192			.len = 4,
193			.cs_change = 1,
194		}, {
195			.tx_buf = &st->d32[1],
196			.rx_buf = &st->d32[2],
197			.len = 4,
198		},
199	};
200	int ret;
201
202	st->d32[0] = cpu_to_be32(
203		(AD5758_WR_FLAG_MSK(AD5758_TWO_STAGE_READBACK_SELECT) << 24) |
204		(addr << 8));
205	st->d32[1] = cpu_to_be32(AD5758_WR_FLAG_MSK(AD5758_NOP) << 24);
206
207	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
208	if (ret < 0)
209		return ret;
210
211	return (be32_to_cpu(st->d32[2]) >> 8) & 0xFFFF;
212}
213
214static int ad5758_spi_reg_write(struct ad5758_state *st,
215				unsigned int addr,
216				unsigned int val)
217{
218	st->d32[0] = cpu_to_be32((AD5758_WR_FLAG_MSK(addr) << 24) |
219				 ((val & 0xFFFF) << 8));
220
221	return spi_write(st->spi, &st->d32[0], sizeof(st->d32[0]));
222}
223
224static int ad5758_spi_write_mask(struct ad5758_state *st,
225				 unsigned int addr,
226				 unsigned long int mask,
227				 unsigned int val)
228{
229	int regval;
230
231	regval = ad5758_spi_reg_read(st, addr);
232	if (regval < 0)
233		return regval;
234
235	regval &= ~mask;
236	regval |= val;
237
238	return ad5758_spi_reg_write(st, addr, regval);
239}
240
241static int cmpfunc(const void *a, const void *b)
242{
243	return *(int *)a - *(int *)b;
244}
245
246static int ad5758_find_closest_match(const int *array,
247				     unsigned int size, int val)
248{
249	int i;
250
251	for (i = 0; i < size; i++) {
252		if (val <= array[i])
253			return i;
254	}
255
256	return size - 1;
257}
258
259static int ad5758_wait_for_task_complete(struct ad5758_state *st,
260					 unsigned int reg,
261					 unsigned int mask)
262{
263	unsigned int timeout;
264	int ret;
265
266	timeout = 10;
267	do {
268		ret = ad5758_spi_reg_read(st, reg);
269		if (ret < 0)
270			return ret;
271
272		if (!(ret & mask))
273			return 0;
274
275		usleep_range(100, 1000);
276	} while (--timeout);
277
278	dev_err(&st->spi->dev,
279		"Error reading bit 0x%x in 0x%x register\n", mask, reg);
280
281	return -EIO;
282}
283
284static int ad5758_calib_mem_refresh(struct ad5758_state *st)
285{
286	int ret;
287
288	ret = ad5758_spi_reg_write(st, AD5758_KEY,
289				   AD5758_KEY_CODE_CALIB_MEM_REFRESH);
290	if (ret < 0) {
291		dev_err(&st->spi->dev,
292			"Failed to initiate a calibration memory refresh\n");
293		return ret;
294	}
295
296	/* Wait to allow time for the internal calibrations to complete */
297	return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
298					     AD5758_CAL_MEM_UNREFRESHED_MSK);
299}
300
301static int ad5758_soft_reset(struct ad5758_state *st)
302{
303	int ret;
304
305	ret = ad5758_spi_reg_write(st, AD5758_KEY, AD5758_KEY_CODE_RESET_1);
306	if (ret < 0)
307		return ret;
308
309	ret = ad5758_spi_reg_write(st, AD5758_KEY, AD5758_KEY_CODE_RESET_2);
310
311	/* Perform a software reset and wait at least 100us */
312	usleep_range(100, 1000);
313
314	return ret;
315}
316
317static int ad5758_set_dc_dc_conv_mode(struct ad5758_state *st,
318				      enum ad5758_dc_dc_mode mode)
319{
320	int ret;
321
322	/*
323	 * The ENABLE_PPC_BUFFERS bit must be set prior to enabling PPC current
324	 * mode.
325	 */
326	if (mode == AD5758_DCDC_MODE_PPC_CURRENT) {
327		ret  = ad5758_spi_write_mask(st, AD5758_ADC_CONFIG,
328				    AD5758_ADC_CONFIG_PPC_BUF_MSK,
329				    AD5758_ADC_CONFIG_PPC_BUF_EN(1));
330		if (ret < 0)
331			return ret;
332	}
333
334	ret = ad5758_spi_write_mask(st, AD5758_DCDC_CONFIG1,
335				    AD5758_DCDC_CONFIG1_DCDC_MODE_MSK,
336				    AD5758_DCDC_CONFIG1_DCDC_MODE_MODE(mode));
337	if (ret < 0)
338		return ret;
339
340	/*
341	 * Poll the BUSY_3WI bit in the DCDC_CONFIG2 register until it is 0.
342	 * This allows the 3-wire interface communication to complete.
343	 */
344	ret = ad5758_wait_for_task_complete(st, AD5758_DCDC_CONFIG2,
345					    AD5758_DCDC_CONFIG2_BUSY_3WI_MSK);
346	if (ret < 0)
347		return ret;
348
349	st->dc_dc_mode = mode;
350
351	return ret;
352}
353
354static int ad5758_set_dc_dc_ilim(struct ad5758_state *st, unsigned int ilim)
355{
356	int ret;
357
358	ret = ad5758_spi_write_mask(st, AD5758_DCDC_CONFIG2,
359				    AD5758_DCDC_CONFIG2_ILIMIT_MSK,
360				    AD5758_DCDC_CONFIG2_ILIMIT_MODE(ilim));
361	if (ret < 0)
362		return ret;
363	/*
364	 * Poll the BUSY_3WI bit in the DCDC_CONFIG2 register until it is 0.
365	 * This allows the 3-wire interface communication to complete.
366	 */
367	return ad5758_wait_for_task_complete(st, AD5758_DCDC_CONFIG2,
368					     AD5758_DCDC_CONFIG2_BUSY_3WI_MSK);
369}
370
371static int ad5758_slew_rate_set(struct ad5758_state *st,
372				unsigned int sr_clk_idx,
373				unsigned int sr_step_idx)
374{
375	unsigned int mode;
376	unsigned long int mask;
377	int ret;
378
379	mask = AD5758_DAC_CONFIG_SR_EN_MSK |
380	       AD5758_DAC_CONFIG_SR_CLOCK_MSK |
381	       AD5758_DAC_CONFIG_SR_STEP_MSK;
382	mode = AD5758_DAC_CONFIG_SR_EN_MODE(1) |
383	       AD5758_DAC_CONFIG_SR_STEP_MODE(sr_step_idx) |
384	       AD5758_DAC_CONFIG_SR_CLOCK_MODE(sr_clk_idx);
385
386	ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG, mask, mode);
387	if (ret < 0)
388		return ret;
389
390	/* Wait to allow time for the internal calibrations to complete */
391	return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
392					     AD5758_CAL_MEM_UNREFRESHED_MSK);
393}
394
395static int ad5758_slew_rate_config(struct ad5758_state *st)
396{
397	unsigned int sr_clk_idx, sr_step_idx;
398	int i, res;
399	s64 diff_new, diff_old;
400	u64 sr_step, calc_slew_time;
401
402	sr_clk_idx = 0;
403	sr_step_idx = 0;
404	diff_old = S64_MAX;
405	/*
406	 * The slew time can be determined by using the formula:
407	 * Slew Time = (Full Scale Out / (Step Size x Update Clk Freq))
408	 * where Slew time is expressed in microseconds
409	 * Given the desired slew time, the following algorithm determines the
410	 * best match for the step size and the update clock frequency.
411	 */
412	for (i = 0; i < ARRAY_SIZE(ad5758_sr_clk); i++) {
413		/*
414		 * Go through each valid update clock freq and determine a raw
415		 * value for the step size by using the formula:
416		 * Step Size = Full Scale Out / (Update Clk Freq * Slew Time)
417		 */
418		sr_step = AD5758_FULL_SCALE_MICRO;
419		do_div(sr_step, ad5758_sr_clk[i]);
420		do_div(sr_step, st->slew_time);
421		/*
422		 * After a raw value for step size was determined, find the
423		 * closest valid match
424		 */
425		res = ad5758_find_closest_match(ad5758_sr_step,
426						ARRAY_SIZE(ad5758_sr_step),
427						sr_step);
428		/* Calculate the slew time */
429		calc_slew_time = AD5758_FULL_SCALE_MICRO;
430		do_div(calc_slew_time, ad5758_sr_step[res]);
431		do_div(calc_slew_time, ad5758_sr_clk[i]);
432		/*
433		 * Determine with how many microseconds the calculated slew time
434		 * is different from the desired slew time and store the diff
435		 * for the next iteration
436		 */
437		diff_new = abs(st->slew_time - calc_slew_time);
438		if (diff_new < diff_old) {
439			diff_old = diff_new;
440			sr_clk_idx = i;
441			sr_step_idx = res;
442		}
443	}
444
445	return ad5758_slew_rate_set(st, sr_clk_idx, sr_step_idx);
446}
447
448static int ad5758_set_out_range(struct ad5758_state *st, int range)
449{
450	int ret;
451
452	ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
453				    AD5758_DAC_CONFIG_RANGE_MSK,
454				    AD5758_DAC_CONFIG_RANGE_MODE(range));
455	if (ret < 0)
456		return ret;
457
458	/* Wait to allow time for the internal calibrations to complete */
459	return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
460					     AD5758_CAL_MEM_UNREFRESHED_MSK);
461}
462
463static int ad5758_internal_buffers_en(struct ad5758_state *st, bool enable)
464{
465	int ret;
466
467	ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
468				    AD5758_DAC_CONFIG_INT_EN_MSK,
469				    AD5758_DAC_CONFIG_INT_EN_MODE(enable));
470	if (ret < 0)
471		return ret;
472
473	/* Wait to allow time for the internal calibrations to complete */
474	return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
475					     AD5758_CAL_MEM_UNREFRESHED_MSK);
476}
477
478static int ad5758_reset(struct ad5758_state *st)
479{
480	if (st->gpio_reset) {
481		gpiod_set_value(st->gpio_reset, 0);
482		usleep_range(100, 1000);
483		gpiod_set_value(st->gpio_reset, 1);
484		usleep_range(100, 1000);
485
486		return 0;
487	} else {
488		/* Perform a software reset */
489		return ad5758_soft_reset(st);
490	}
491}
492
493static int ad5758_reg_access(struct iio_dev *indio_dev,
494			     unsigned int reg,
495			     unsigned int writeval,
496			     unsigned int *readval)
497{
498	struct ad5758_state *st = iio_priv(indio_dev);
499	int ret;
500
501	mutex_lock(&st->lock);
502	if (readval) {
503		ret = ad5758_spi_reg_read(st, reg);
504		if (ret < 0) {
505			mutex_unlock(&st->lock);
506			return ret;
507		}
508
509		*readval = ret;
510		ret = 0;
511	} else {
512		ret = ad5758_spi_reg_write(st, reg, writeval);
513	}
514	mutex_unlock(&st->lock);
515
516	return ret;
517}
518
519static int ad5758_read_raw(struct iio_dev *indio_dev,
520			   struct iio_chan_spec const *chan,
521			   int *val, int *val2, long info)
522{
523	struct ad5758_state *st = iio_priv(indio_dev);
524	int max, min, ret;
525
526	switch (info) {
527	case IIO_CHAN_INFO_RAW:
528		mutex_lock(&st->lock);
529		ret = ad5758_spi_reg_read(st, AD5758_DAC_INPUT);
530		mutex_unlock(&st->lock);
531		if (ret < 0)
532			return ret;
533
534		*val = ret;
535		return IIO_VAL_INT;
536	case IIO_CHAN_INFO_SCALE:
537		min = st->out_range.min;
538		max = st->out_range.max;
539		*val = (max - min) / 1000;
540		*val2 = 16;
541		return IIO_VAL_FRACTIONAL_LOG2;
542	case IIO_CHAN_INFO_OFFSET:
543		min = st->out_range.min;
544		max = st->out_range.max;
545		*val = ((min * (1 << 16)) / (max - min)) / 1000;
546		return IIO_VAL_INT;
547	default:
548		return -EINVAL;
549	}
550}
551
552static int ad5758_write_raw(struct iio_dev *indio_dev,
553			    struct iio_chan_spec const *chan,
554			    int val, int val2, long info)
555{
556	struct ad5758_state *st = iio_priv(indio_dev);
557	int ret;
558
559	switch (info) {
560	case IIO_CHAN_INFO_RAW:
561		mutex_lock(&st->lock);
562		ret = ad5758_spi_reg_write(st, AD5758_DAC_INPUT, val);
563		mutex_unlock(&st->lock);
564		return ret;
565	default:
566		return -EINVAL;
567	}
568}
569
570static ssize_t ad5758_read_powerdown(struct iio_dev *indio_dev,
571				     uintptr_t priv,
572				     const struct iio_chan_spec *chan,
573				     char *buf)
574{
575	struct ad5758_state *st = iio_priv(indio_dev);
576
577	return sprintf(buf, "%d\n", st->pwr_down);
578}
579
580static ssize_t ad5758_write_powerdown(struct iio_dev *indio_dev,
581				      uintptr_t priv,
582				      struct iio_chan_spec const *chan,
583				      const char *buf, size_t len)
584{
585	struct ad5758_state *st = iio_priv(indio_dev);
586	bool pwr_down;
587	unsigned int dac_config_mode, val;
588	unsigned long int dac_config_msk;
589	int ret;
590
591	ret = kstrtobool(buf, &pwr_down);
592	if (ret)
593		return ret;
594
595	mutex_lock(&st->lock);
596	if (pwr_down)
597		val = 0;
598	else
599		val = 1;
600
601	dac_config_mode = AD5758_DAC_CONFIG_OUT_EN_MODE(val) |
602			  AD5758_DAC_CONFIG_INT_EN_MODE(val);
603	dac_config_msk = AD5758_DAC_CONFIG_OUT_EN_MSK |
604			 AD5758_DAC_CONFIG_INT_EN_MSK;
605
606	ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
607				    dac_config_msk,
608				    dac_config_mode);
609	if (ret < 0)
610		goto err_unlock;
611
612	st->pwr_down = pwr_down;
613
614err_unlock:
615	mutex_unlock(&st->lock);
616
617	return ret ? ret : len;
618}
619
620static const struct iio_info ad5758_info = {
621	.read_raw = ad5758_read_raw,
622	.write_raw = ad5758_write_raw,
623	.debugfs_reg_access = &ad5758_reg_access,
624};
625
626static const struct iio_chan_spec_ext_info ad5758_ext_info[] = {
627	{
628		.name = "powerdown",
629		.read = ad5758_read_powerdown,
630		.write = ad5758_write_powerdown,
631		.shared = IIO_SHARED_BY_TYPE,
632	},
633	{ }
634};
635
636#define AD5758_DAC_CHAN(_chan_type) {				\
637	.type = (_chan_type),					\
638	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_RAW) |	\
639		BIT(IIO_CHAN_INFO_SCALE) |			\
640		BIT(IIO_CHAN_INFO_OFFSET),			\
641	.indexed = 1,						\
642	.output = 1,						\
643	.ext_info = ad5758_ext_info,				\
644}
645
646static const struct iio_chan_spec ad5758_voltage_ch[] = {
647	AD5758_DAC_CHAN(IIO_VOLTAGE)
648};
649
650static const struct iio_chan_spec ad5758_current_ch[] = {
651	AD5758_DAC_CHAN(IIO_CURRENT)
652};
653
654static bool ad5758_is_valid_mode(enum ad5758_dc_dc_mode mode)
655{
656	switch (mode) {
657	case AD5758_DCDC_MODE_DPC_CURRENT:
658	case AD5758_DCDC_MODE_DPC_VOLTAGE:
659	case AD5758_DCDC_MODE_PPC_CURRENT:
660		return true;
661	default:
662		return false;
663	}
664}
665
666static int ad5758_crc_disable(struct ad5758_state *st)
667{
668	unsigned int mask;
669
670	mask = (AD5758_WR_FLAG_MSK(AD5758_DIGITAL_DIAG_CONFIG) << 24) | 0x5C3A;
671	st->d32[0] = cpu_to_be32(mask);
672
673	return spi_write(st->spi, &st->d32[0], 4);
674}
675
676static int ad5758_find_out_range(struct ad5758_state *st,
677				 const struct ad5758_range *range,
678				 unsigned int size,
679				 int min, int max)
680{
681	int i;
682
683	for (i = 0; i < size; i++) {
684		if ((min == range[i].min) && (max == range[i].max)) {
685			st->out_range.reg = range[i].reg;
686			st->out_range.min = range[i].min;
687			st->out_range.max = range[i].max;
688
689			return 0;
690		}
691	}
692
693	return -EINVAL;
694}
695
696static int ad5758_parse_dt(struct ad5758_state *st)
697{
698	unsigned int tmp, tmparray[2], size;
699	const struct ad5758_range *range;
700	int *index, ret;
701
702	st->dc_dc_ilim = 0;
703	ret = device_property_read_u32(&st->spi->dev,
704				       "adi,dc-dc-ilim-microamp", &tmp);
705	if (ret) {
706		dev_dbg(&st->spi->dev,
707			"Missing \"dc-dc-ilim-microamp\" property\n");
708	} else {
709		index = bsearch(&tmp, ad5758_dc_dc_ilim,
710				ARRAY_SIZE(ad5758_dc_dc_ilim),
711				sizeof(int), cmpfunc);
712		if (!index)
713			dev_dbg(&st->spi->dev, "dc-dc-ilim out of range\n");
714		else
715			st->dc_dc_ilim = index - ad5758_dc_dc_ilim;
716	}
717
718	ret = device_property_read_u32(&st->spi->dev, "adi,dc-dc-mode",
719				       &st->dc_dc_mode);
720	if (ret) {
721		dev_err(&st->spi->dev, "Missing \"dc-dc-mode\" property\n");
722		return ret;
723	}
724
725	if (!ad5758_is_valid_mode(st->dc_dc_mode))
726		return -EINVAL;
727
728	if (st->dc_dc_mode == AD5758_DCDC_MODE_DPC_VOLTAGE) {
729		ret = device_property_read_u32_array(&st->spi->dev,
730						     "adi,range-microvolt",
731						     tmparray, 2);
732		if (ret) {
733			dev_err(&st->spi->dev,
734				"Missing \"range-microvolt\" property\n");
735			return ret;
736		}
737		range = ad5758_voltage_range;
738		size = ARRAY_SIZE(ad5758_voltage_range);
739	} else {
740		ret = device_property_read_u32_array(&st->spi->dev,
741						     "adi,range-microamp",
742						     tmparray, 2);
743		if (ret) {
744			dev_err(&st->spi->dev,
745				"Missing \"range-microamp\" property\n");
746			return ret;
747		}
748		range = ad5758_current_range;
749		size = ARRAY_SIZE(ad5758_current_range);
750	}
751
752	ret = ad5758_find_out_range(st, range, size, tmparray[0], tmparray[1]);
753	if (ret) {
754		dev_err(&st->spi->dev, "range invalid\n");
755		return ret;
756	}
757
758	ret = device_property_read_u32(&st->spi->dev, "adi,slew-time-us", &tmp);
759	if (ret) {
760		dev_dbg(&st->spi->dev, "Missing \"slew-time-us\" property\n");
761		st->slew_time = 0;
762	} else {
763		st->slew_time = tmp;
764	}
765
766	return 0;
767}
768
769static int ad5758_init(struct ad5758_state *st)
770{
771	int regval, ret;
772
773	st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
774						 GPIOD_OUT_HIGH);
775	if (IS_ERR(st->gpio_reset))
776		return PTR_ERR(st->gpio_reset);
777
778	/* Disable CRC checks */
779	ret = ad5758_crc_disable(st);
780	if (ret < 0)
781		return ret;
782
783	/* Perform a reset */
784	ret = ad5758_reset(st);
785	if (ret < 0)
786		return ret;
787
788	/* Disable CRC checks */
789	ret = ad5758_crc_disable(st);
790	if (ret < 0)
791		return ret;
792
793	/* Perform a calibration memory refresh */
794	ret = ad5758_calib_mem_refresh(st);
795	if (ret < 0)
796		return ret;
797
798	regval = ad5758_spi_reg_read(st, AD5758_DIGITAL_DIAG_RESULTS);
799	if (regval < 0)
800		return regval;
801
802	/* Clear all the error flags */
803	ret = ad5758_spi_reg_write(st, AD5758_DIGITAL_DIAG_RESULTS, regval);
804	if (ret < 0)
805		return ret;
806
807	/* Set the dc-to-dc current limit */
808	ret = ad5758_set_dc_dc_ilim(st, st->dc_dc_ilim);
809	if (ret < 0)
810		return ret;
811
812	/* Configure the dc-to-dc controller mode */
813	ret = ad5758_set_dc_dc_conv_mode(st, st->dc_dc_mode);
814	if (ret < 0)
815		return ret;
816
817	/* Configure the output range */
818	ret = ad5758_set_out_range(st, st->out_range.reg);
819	if (ret < 0)
820		return ret;
821
822	/* Enable Slew Rate Control, set the slew rate clock and step */
823	if (st->slew_time) {
824		ret = ad5758_slew_rate_config(st);
825		if (ret < 0)
826			return ret;
827	}
828
829	/* Power up the DAC and internal (INT) amplifiers */
830	ret = ad5758_internal_buffers_en(st, 1);
831	if (ret < 0)
832		return ret;
833
834	/* Enable VIOUT */
835	return ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
836				     AD5758_DAC_CONFIG_OUT_EN_MSK,
837				     AD5758_DAC_CONFIG_OUT_EN_MODE(1));
838}
839
840static int ad5758_probe(struct spi_device *spi)
841{
842	struct ad5758_state *st;
843	struct iio_dev *indio_dev;
844	int ret;
845
846	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
847	if (!indio_dev)
848		return -ENOMEM;
849
850	st = iio_priv(indio_dev);
851	spi_set_drvdata(spi, indio_dev);
852
853	st->spi = spi;
854
855	mutex_init(&st->lock);
856
857	indio_dev->name = spi_get_device_id(spi)->name;
858	indio_dev->info = &ad5758_info;
859	indio_dev->modes = INDIO_DIRECT_MODE;
860	indio_dev->num_channels = 1;
861
862	ret = ad5758_parse_dt(st);
863	if (ret < 0)
864		return ret;
865
866	if (st->dc_dc_mode == AD5758_DCDC_MODE_DPC_VOLTAGE)
867		indio_dev->channels = ad5758_voltage_ch;
868	else
869		indio_dev->channels = ad5758_current_ch;
870
871	ret = ad5758_init(st);
872	if (ret < 0) {
873		dev_err(&spi->dev, "AD5758 init failed\n");
874		return ret;
875	}
876
877	return devm_iio_device_register(&st->spi->dev, indio_dev);
878}
879
880static const struct spi_device_id ad5758_id[] = {
881	{ "ad5758", 0 },
882	{}
883};
884MODULE_DEVICE_TABLE(spi, ad5758_id);
885
886static const struct of_device_id ad5758_of_match[] = {
887        { .compatible = "adi,ad5758" },
888        { },
889};
890MODULE_DEVICE_TABLE(of, ad5758_of_match);
891
892static struct spi_driver ad5758_driver = {
893	.driver = {
894		.name = KBUILD_MODNAME,
895		.of_match_table = ad5758_of_match,
896	},
897	.probe = ad5758_probe,
898	.id_table = ad5758_id,
899};
900
901module_spi_driver(ad5758_driver);
902
903MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
904MODULE_DESCRIPTION("Analog Devices AD5758 DAC");
905MODULE_LICENSE("GPL v2");
906