xref: /openbmc/linux/drivers/iio/dac/ad5758.c (revision f191fe4f)
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/mod_devicetable.h>
14 #include <linux/property.h>
15 #include <linux/spi/spi.h>
16 #include <linux/gpio/consumer.h>
17 
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 
21 /* AD5758 registers definition */
22 #define AD5758_NOP				0x00
23 #define AD5758_DAC_INPUT			0x01
24 #define AD5758_DAC_OUTPUT			0x02
25 #define AD5758_CLEAR_CODE			0x03
26 #define AD5758_USER_GAIN			0x04
27 #define AD5758_USER_OFFSET			0x05
28 #define AD5758_DAC_CONFIG			0x06
29 #define AD5758_SW_LDAC				0x07
30 #define AD5758_KEY				0x08
31 #define AD5758_GP_CONFIG1			0x09
32 #define AD5758_GP_CONFIG2			0x0A
33 #define AD5758_DCDC_CONFIG1			0x0B
34 #define AD5758_DCDC_CONFIG2			0x0C
35 #define AD5758_WDT_CONFIG			0x0F
36 #define AD5758_DIGITAL_DIAG_CONFIG		0x10
37 #define AD5758_ADC_CONFIG			0x11
38 #define AD5758_FAULT_PIN_CONFIG			0x12
39 #define AD5758_TWO_STAGE_READBACK_SELECT	0x13
40 #define AD5758_DIGITAL_DIAG_RESULTS		0x14
41 #define AD5758_ANALOG_DIAG_RESULTS		0x15
42 #define AD5758_STATUS				0x16
43 #define AD5758_CHIP_ID				0x17
44 #define AD5758_FREQ_MONITOR			0x18
45 #define AD5758_DEVICE_ID_0			0x19
46 #define AD5758_DEVICE_ID_1			0x1A
47 #define AD5758_DEVICE_ID_2			0x1B
48 #define AD5758_DEVICE_ID_3			0x1C
49 
50 /* AD5758_DAC_CONFIG */
51 #define AD5758_DAC_CONFIG_RANGE_MSK		GENMASK(3, 0)
52 #define AD5758_DAC_CONFIG_RANGE_MODE(x)		(((x) & 0xF) << 0)
53 #define AD5758_DAC_CONFIG_INT_EN_MSK		BIT(5)
54 #define AD5758_DAC_CONFIG_INT_EN_MODE(x)	(((x) & 0x1) << 5)
55 #define AD5758_DAC_CONFIG_OUT_EN_MSK		BIT(6)
56 #define AD5758_DAC_CONFIG_OUT_EN_MODE(x)	(((x) & 0x1) << 6)
57 #define AD5758_DAC_CONFIG_SR_EN_MSK		BIT(8)
58 #define AD5758_DAC_CONFIG_SR_EN_MODE(x)		(((x) & 0x1) << 8)
59 #define AD5758_DAC_CONFIG_SR_CLOCK_MSK		GENMASK(12, 9)
60 #define AD5758_DAC_CONFIG_SR_CLOCK_MODE(x)	(((x) & 0xF) << 9)
61 #define AD5758_DAC_CONFIG_SR_STEP_MSK		GENMASK(15, 13)
62 #define AD5758_DAC_CONFIG_SR_STEP_MODE(x)	(((x) & 0x7) << 13)
63 
64 /* AD5758_KEY */
65 #define AD5758_KEY_CODE_RESET_1			0x15FA
66 #define AD5758_KEY_CODE_RESET_2			0xAF51
67 #define AD5758_KEY_CODE_SINGLE_ADC_CONV		0x1ADC
68 #define AD5758_KEY_CODE_RESET_WDT		0x0D06
69 #define AD5758_KEY_CODE_CALIB_MEM_REFRESH	0xFCBA
70 
71 /* AD5758_DCDC_CONFIG1 */
72 #define AD5758_DCDC_CONFIG1_DCDC_VPROG_MSK	GENMASK(4, 0)
73 #define AD5758_DCDC_CONFIG1_DCDC_VPROG_MODE(x)	(((x) & 0x1F) << 0)
74 #define AD5758_DCDC_CONFIG1_DCDC_MODE_MSK	GENMASK(6, 5)
75 #define AD5758_DCDC_CONFIG1_DCDC_MODE_MODE(x)	(((x) & 0x3) << 5)
76 
77 /* AD5758_DCDC_CONFIG2 */
78 #define AD5758_DCDC_CONFIG2_ILIMIT_MSK		GENMASK(3, 1)
79 #define AD5758_DCDC_CONFIG2_ILIMIT_MODE(x)	(((x) & 0x7) << 1)
80 #define AD5758_DCDC_CONFIG2_INTR_SAT_3WI_MSK	BIT(11)
81 #define AD5758_DCDC_CONFIG2_BUSY_3WI_MSK	BIT(12)
82 
83 /* AD5758_DIGITAL_DIAG_RESULTS */
84 #define AD5758_CAL_MEM_UNREFRESHED_MSK		BIT(15)
85 
86 /* AD5758_ADC_CONFIG */
87 #define AD5758_ADC_CONFIG_PPC_BUF_EN(x)		(((x) & 0x1) << 11)
88 #define AD5758_ADC_CONFIG_PPC_BUF_MSK		BIT(11)
89 
90 #define AD5758_WR_FLAG_MSK(x)		(0x80 | ((x) & 0x1F))
91 
92 #define AD5758_FULL_SCALE_MICRO	65535000000ULL
93 
94 struct ad5758_range {
95 	int reg;
96 	int min;
97 	int max;
98 };
99 
100 /**
101  * struct ad5758_state - driver instance specific data
102  * @spi:	spi_device
103  * @lock:	mutex lock
104  * @gpio_reset:	gpio descriptor for the reset line
105  * @out_range:	struct which stores the output range
106  * @dc_dc_mode:	variable which stores the mode of operation
107  * @dc_dc_ilim:	variable which stores the dc-to-dc converter current limit
108  * @slew_time:	variable which stores the target slew time
109  * @pwr_down:	variable which contains whether a channel is powered down or not
110  * @d32:	spi transfer buffers
111  */
112 struct ad5758_state {
113 	struct spi_device *spi;
114 	struct mutex lock;
115 	struct gpio_desc *gpio_reset;
116 	struct ad5758_range out_range;
117 	unsigned int dc_dc_mode;
118 	unsigned int dc_dc_ilim;
119 	unsigned int slew_time;
120 	bool pwr_down;
121 	__be32 d32[3];
122 };
123 
124 /*
125  * Output ranges corresponding to bits [3:0] from DAC_CONFIG register
126  * 0000: 0 V to 5 V voltage range
127  * 0001: 0 V to 10 V voltage range
128  * 0010: ±5 V voltage range
129  * 0011: ±10 V voltage range
130  * 1000: 0 mA to 20 mA current range
131  * 1001: 0 mA to 24 mA current range
132  * 1010: 4 mA to 20 mA current range
133  * 1011: ±20 mA current range
134  * 1100: ±24 mA current range
135  * 1101: -1 mA to +22 mA current range
136  */
137 enum ad5758_output_range {
138 	AD5758_RANGE_0V_5V,
139 	AD5758_RANGE_0V_10V,
140 	AD5758_RANGE_PLUSMINUS_5V,
141 	AD5758_RANGE_PLUSMINUS_10V,
142 	AD5758_RANGE_0mA_20mA = 8,
143 	AD5758_RANGE_0mA_24mA,
144 	AD5758_RANGE_4mA_24mA,
145 	AD5758_RANGE_PLUSMINUS_20mA,
146 	AD5758_RANGE_PLUSMINUS_24mA,
147 	AD5758_RANGE_MINUS_1mA_PLUS_22mA,
148 };
149 
150 enum ad5758_dc_dc_mode {
151 	AD5758_DCDC_MODE_POWER_OFF,
152 	AD5758_DCDC_MODE_DPC_CURRENT,
153 	AD5758_DCDC_MODE_DPC_VOLTAGE,
154 	AD5758_DCDC_MODE_PPC_CURRENT,
155 };
156 
157 static const struct ad5758_range ad5758_voltage_range[] = {
158 	{ AD5758_RANGE_0V_5V, 0, 5000000 },
159 	{ AD5758_RANGE_0V_10V, 0, 10000000 },
160 	{ AD5758_RANGE_PLUSMINUS_5V, -5000000, 5000000 },
161 	{ AD5758_RANGE_PLUSMINUS_10V, -10000000, 10000000 }
162 };
163 
164 static const struct ad5758_range ad5758_current_range[] = {
165 	{ AD5758_RANGE_0mA_20mA, 0, 20000},
166 	{ AD5758_RANGE_0mA_24mA, 0, 24000 },
167 	{ AD5758_RANGE_4mA_24mA, 4, 24000 },
168 	{ AD5758_RANGE_PLUSMINUS_20mA, -20000, 20000 },
169 	{ AD5758_RANGE_PLUSMINUS_24mA, -24000, 24000 },
170 	{ AD5758_RANGE_MINUS_1mA_PLUS_22mA, -1000, 22000 },
171 };
172 
173 static const int ad5758_sr_clk[16] = {
174 	240000, 200000, 150000, 128000, 64000, 32000, 16000, 8000, 4000, 2000,
175 	1000, 512, 256, 128, 64, 16
176 };
177 
178 static const int ad5758_sr_step[8] = {
179 	4, 12, 64, 120, 256, 500, 1820, 2048
180 };
181 
182 static const int ad5758_dc_dc_ilim[6] = {
183 	150000, 200000, 250000, 300000, 350000, 400000
184 };
185 
ad5758_spi_reg_read(struct ad5758_state * st,unsigned int addr)186 static int ad5758_spi_reg_read(struct ad5758_state *st, unsigned int addr)
187 {
188 	struct spi_transfer t[] = {
189 		{
190 			.tx_buf = &st->d32[0],
191 			.len = 4,
192 			.cs_change = 1,
193 		}, {
194 			.tx_buf = &st->d32[1],
195 			.rx_buf = &st->d32[2],
196 			.len = 4,
197 		},
198 	};
199 	int ret;
200 
201 	st->d32[0] = cpu_to_be32(
202 		(AD5758_WR_FLAG_MSK(AD5758_TWO_STAGE_READBACK_SELECT) << 24) |
203 		(addr << 8));
204 	st->d32[1] = cpu_to_be32(AD5758_WR_FLAG_MSK(AD5758_NOP) << 24);
205 
206 	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
207 	if (ret < 0)
208 		return ret;
209 
210 	return (be32_to_cpu(st->d32[2]) >> 8) & 0xFFFF;
211 }
212 
ad5758_spi_reg_write(struct ad5758_state * st,unsigned int addr,unsigned int val)213 static int ad5758_spi_reg_write(struct ad5758_state *st,
214 				unsigned int addr,
215 				unsigned int val)
216 {
217 	st->d32[0] = cpu_to_be32((AD5758_WR_FLAG_MSK(addr) << 24) |
218 				 ((val & 0xFFFF) << 8));
219 
220 	return spi_write(st->spi, &st->d32[0], sizeof(st->d32[0]));
221 }
222 
ad5758_spi_write_mask(struct ad5758_state * st,unsigned int addr,unsigned long int mask,unsigned int val)223 static int ad5758_spi_write_mask(struct ad5758_state *st,
224 				 unsigned int addr,
225 				 unsigned long int mask,
226 				 unsigned int val)
227 {
228 	int regval;
229 
230 	regval = ad5758_spi_reg_read(st, addr);
231 	if (regval < 0)
232 		return regval;
233 
234 	regval &= ~mask;
235 	regval |= val;
236 
237 	return ad5758_spi_reg_write(st, addr, regval);
238 }
239 
cmpfunc(const void * a,const void * b)240 static int cmpfunc(const void *a, const void *b)
241 {
242 	return *(int *)a - *(int *)b;
243 }
244 
ad5758_find_closest_match(const int * array,unsigned int size,int val)245 static int ad5758_find_closest_match(const int *array,
246 				     unsigned int size, int val)
247 {
248 	int i;
249 
250 	for (i = 0; i < size; i++) {
251 		if (val <= array[i])
252 			return i;
253 	}
254 
255 	return size - 1;
256 }
257 
ad5758_wait_for_task_complete(struct ad5758_state * st,unsigned int reg,unsigned int mask)258 static int ad5758_wait_for_task_complete(struct ad5758_state *st,
259 					 unsigned int reg,
260 					 unsigned int mask)
261 {
262 	unsigned int timeout;
263 	int ret;
264 
265 	timeout = 10;
266 	do {
267 		ret = ad5758_spi_reg_read(st, reg);
268 		if (ret < 0)
269 			return ret;
270 
271 		if (!(ret & mask))
272 			return 0;
273 
274 		usleep_range(100, 1000);
275 	} while (--timeout);
276 
277 	dev_err(&st->spi->dev,
278 		"Error reading bit 0x%x in 0x%x register\n", mask, reg);
279 
280 	return -EIO;
281 }
282 
ad5758_calib_mem_refresh(struct ad5758_state * st)283 static int ad5758_calib_mem_refresh(struct ad5758_state *st)
284 {
285 	int ret;
286 
287 	ret = ad5758_spi_reg_write(st, AD5758_KEY,
288 				   AD5758_KEY_CODE_CALIB_MEM_REFRESH);
289 	if (ret < 0) {
290 		dev_err(&st->spi->dev,
291 			"Failed to initiate a calibration memory refresh\n");
292 		return ret;
293 	}
294 
295 	/* Wait to allow time for the internal calibrations to complete */
296 	return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
297 					     AD5758_CAL_MEM_UNREFRESHED_MSK);
298 }
299 
ad5758_soft_reset(struct ad5758_state * st)300 static int ad5758_soft_reset(struct ad5758_state *st)
301 {
302 	int ret;
303 
304 	ret = ad5758_spi_reg_write(st, AD5758_KEY, AD5758_KEY_CODE_RESET_1);
305 	if (ret < 0)
306 		return ret;
307 
308 	ret = ad5758_spi_reg_write(st, AD5758_KEY, AD5758_KEY_CODE_RESET_2);
309 
310 	/* Perform a software reset and wait at least 100us */
311 	usleep_range(100, 1000);
312 
313 	return ret;
314 }
315 
ad5758_set_dc_dc_conv_mode(struct ad5758_state * st,enum ad5758_dc_dc_mode mode)316 static int ad5758_set_dc_dc_conv_mode(struct ad5758_state *st,
317 				      enum ad5758_dc_dc_mode mode)
318 {
319 	int ret;
320 
321 	/*
322 	 * The ENABLE_PPC_BUFFERS bit must be set prior to enabling PPC current
323 	 * mode.
324 	 */
325 	if (mode == AD5758_DCDC_MODE_PPC_CURRENT) {
326 		ret  = ad5758_spi_write_mask(st, AD5758_ADC_CONFIG,
327 				    AD5758_ADC_CONFIG_PPC_BUF_MSK,
328 				    AD5758_ADC_CONFIG_PPC_BUF_EN(1));
329 		if (ret < 0)
330 			return ret;
331 	}
332 
333 	ret = ad5758_spi_write_mask(st, AD5758_DCDC_CONFIG1,
334 				    AD5758_DCDC_CONFIG1_DCDC_MODE_MSK,
335 				    AD5758_DCDC_CONFIG1_DCDC_MODE_MODE(mode));
336 	if (ret < 0)
337 		return ret;
338 
339 	/*
340 	 * Poll the BUSY_3WI bit in the DCDC_CONFIG2 register until it is 0.
341 	 * This allows the 3-wire interface communication to complete.
342 	 */
343 	ret = ad5758_wait_for_task_complete(st, AD5758_DCDC_CONFIG2,
344 					    AD5758_DCDC_CONFIG2_BUSY_3WI_MSK);
345 	if (ret < 0)
346 		return ret;
347 
348 	st->dc_dc_mode = mode;
349 
350 	return ret;
351 }
352 
ad5758_set_dc_dc_ilim(struct ad5758_state * st,unsigned int ilim)353 static int ad5758_set_dc_dc_ilim(struct ad5758_state *st, unsigned int ilim)
354 {
355 	int ret;
356 
357 	ret = ad5758_spi_write_mask(st, AD5758_DCDC_CONFIG2,
358 				    AD5758_DCDC_CONFIG2_ILIMIT_MSK,
359 				    AD5758_DCDC_CONFIG2_ILIMIT_MODE(ilim));
360 	if (ret < 0)
361 		return ret;
362 	/*
363 	 * Poll the BUSY_3WI bit in the DCDC_CONFIG2 register until it is 0.
364 	 * This allows the 3-wire interface communication to complete.
365 	 */
366 	return ad5758_wait_for_task_complete(st, AD5758_DCDC_CONFIG2,
367 					     AD5758_DCDC_CONFIG2_BUSY_3WI_MSK);
368 }
369 
ad5758_slew_rate_set(struct ad5758_state * st,unsigned int sr_clk_idx,unsigned int sr_step_idx)370 static int ad5758_slew_rate_set(struct ad5758_state *st,
371 				unsigned int sr_clk_idx,
372 				unsigned int sr_step_idx)
373 {
374 	unsigned int mode;
375 	unsigned long int mask;
376 	int ret;
377 
378 	mask = AD5758_DAC_CONFIG_SR_EN_MSK |
379 	       AD5758_DAC_CONFIG_SR_CLOCK_MSK |
380 	       AD5758_DAC_CONFIG_SR_STEP_MSK;
381 	mode = AD5758_DAC_CONFIG_SR_EN_MODE(1) |
382 	       AD5758_DAC_CONFIG_SR_STEP_MODE(sr_step_idx) |
383 	       AD5758_DAC_CONFIG_SR_CLOCK_MODE(sr_clk_idx);
384 
385 	ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG, mask, mode);
386 	if (ret < 0)
387 		return ret;
388 
389 	/* Wait to allow time for the internal calibrations to complete */
390 	return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
391 					     AD5758_CAL_MEM_UNREFRESHED_MSK);
392 }
393 
ad5758_slew_rate_config(struct ad5758_state * st)394 static int ad5758_slew_rate_config(struct ad5758_state *st)
395 {
396 	unsigned int sr_clk_idx, sr_step_idx;
397 	int i, res;
398 	s64 diff_new, diff_old;
399 	u64 sr_step, calc_slew_time;
400 
401 	sr_clk_idx = 0;
402 	sr_step_idx = 0;
403 	diff_old = S64_MAX;
404 	/*
405 	 * The slew time can be determined by using the formula:
406 	 * Slew Time = (Full Scale Out / (Step Size x Update Clk Freq))
407 	 * where Slew time is expressed in microseconds
408 	 * Given the desired slew time, the following algorithm determines the
409 	 * best match for the step size and the update clock frequency.
410 	 */
411 	for (i = 0; i < ARRAY_SIZE(ad5758_sr_clk); i++) {
412 		/*
413 		 * Go through each valid update clock freq and determine a raw
414 		 * value for the step size by using the formula:
415 		 * Step Size = Full Scale Out / (Update Clk Freq * Slew Time)
416 		 */
417 		sr_step = AD5758_FULL_SCALE_MICRO;
418 		do_div(sr_step, ad5758_sr_clk[i]);
419 		do_div(sr_step, st->slew_time);
420 		/*
421 		 * After a raw value for step size was determined, find the
422 		 * closest valid match
423 		 */
424 		res = ad5758_find_closest_match(ad5758_sr_step,
425 						ARRAY_SIZE(ad5758_sr_step),
426 						sr_step);
427 		/* Calculate the slew time */
428 		calc_slew_time = AD5758_FULL_SCALE_MICRO;
429 		do_div(calc_slew_time, ad5758_sr_step[res]);
430 		do_div(calc_slew_time, ad5758_sr_clk[i]);
431 		/*
432 		 * Determine with how many microseconds the calculated slew time
433 		 * is different from the desired slew time and store the diff
434 		 * for the next iteration
435 		 */
436 		diff_new = abs(st->slew_time - calc_slew_time);
437 		if (diff_new < diff_old) {
438 			diff_old = diff_new;
439 			sr_clk_idx = i;
440 			sr_step_idx = res;
441 		}
442 	}
443 
444 	return ad5758_slew_rate_set(st, sr_clk_idx, sr_step_idx);
445 }
446 
ad5758_set_out_range(struct ad5758_state * st,int range)447 static int ad5758_set_out_range(struct ad5758_state *st, int range)
448 {
449 	int ret;
450 
451 	ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
452 				    AD5758_DAC_CONFIG_RANGE_MSK,
453 				    AD5758_DAC_CONFIG_RANGE_MODE(range));
454 	if (ret < 0)
455 		return ret;
456 
457 	/* Wait to allow time for the internal calibrations to complete */
458 	return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
459 					     AD5758_CAL_MEM_UNREFRESHED_MSK);
460 }
461 
ad5758_internal_buffers_en(struct ad5758_state * st,bool enable)462 static int ad5758_internal_buffers_en(struct ad5758_state *st, bool enable)
463 {
464 	int ret;
465 
466 	ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
467 				    AD5758_DAC_CONFIG_INT_EN_MSK,
468 				    AD5758_DAC_CONFIG_INT_EN_MODE(enable));
469 	if (ret < 0)
470 		return ret;
471 
472 	/* Wait to allow time for the internal calibrations to complete */
473 	return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
474 					     AD5758_CAL_MEM_UNREFRESHED_MSK);
475 }
476 
ad5758_reset(struct ad5758_state * st)477 static int ad5758_reset(struct ad5758_state *st)
478 {
479 	if (st->gpio_reset) {
480 		gpiod_set_value(st->gpio_reset, 0);
481 		usleep_range(100, 1000);
482 		gpiod_set_value(st->gpio_reset, 1);
483 		usleep_range(100, 1000);
484 
485 		return 0;
486 	} else {
487 		/* Perform a software reset */
488 		return ad5758_soft_reset(st);
489 	}
490 }
491 
ad5758_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)492 static int ad5758_reg_access(struct iio_dev *indio_dev,
493 			     unsigned int reg,
494 			     unsigned int writeval,
495 			     unsigned int *readval)
496 {
497 	struct ad5758_state *st = iio_priv(indio_dev);
498 	int ret;
499 
500 	mutex_lock(&st->lock);
501 	if (readval) {
502 		ret = ad5758_spi_reg_read(st, reg);
503 		if (ret < 0) {
504 			mutex_unlock(&st->lock);
505 			return ret;
506 		}
507 
508 		*readval = ret;
509 		ret = 0;
510 	} else {
511 		ret = ad5758_spi_reg_write(st, reg, writeval);
512 	}
513 	mutex_unlock(&st->lock);
514 
515 	return ret;
516 }
517 
ad5758_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long info)518 static int ad5758_read_raw(struct iio_dev *indio_dev,
519 			   struct iio_chan_spec const *chan,
520 			   int *val, int *val2, long info)
521 {
522 	struct ad5758_state *st = iio_priv(indio_dev);
523 	int max, min, ret;
524 
525 	switch (info) {
526 	case IIO_CHAN_INFO_RAW:
527 		mutex_lock(&st->lock);
528 		ret = ad5758_spi_reg_read(st, AD5758_DAC_INPUT);
529 		mutex_unlock(&st->lock);
530 		if (ret < 0)
531 			return ret;
532 
533 		*val = ret;
534 		return IIO_VAL_INT;
535 	case IIO_CHAN_INFO_SCALE:
536 		min = st->out_range.min;
537 		max = st->out_range.max;
538 		*val = (max - min) / 1000;
539 		*val2 = 16;
540 		return IIO_VAL_FRACTIONAL_LOG2;
541 	case IIO_CHAN_INFO_OFFSET:
542 		min = st->out_range.min;
543 		max = st->out_range.max;
544 		*val = ((min * (1 << 16)) / (max - min)) / 1000;
545 		return IIO_VAL_INT;
546 	default:
547 		return -EINVAL;
548 	}
549 }
550 
ad5758_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long info)551 static int ad5758_write_raw(struct iio_dev *indio_dev,
552 			    struct iio_chan_spec const *chan,
553 			    int val, int val2, long info)
554 {
555 	struct ad5758_state *st = iio_priv(indio_dev);
556 	int ret;
557 
558 	switch (info) {
559 	case IIO_CHAN_INFO_RAW:
560 		mutex_lock(&st->lock);
561 		ret = ad5758_spi_reg_write(st, AD5758_DAC_INPUT, val);
562 		mutex_unlock(&st->lock);
563 		return ret;
564 	default:
565 		return -EINVAL;
566 	}
567 }
568 
ad5758_read_powerdown(struct iio_dev * indio_dev,uintptr_t priv,const struct iio_chan_spec * chan,char * buf)569 static ssize_t ad5758_read_powerdown(struct iio_dev *indio_dev,
570 				     uintptr_t priv,
571 				     const struct iio_chan_spec *chan,
572 				     char *buf)
573 {
574 	struct ad5758_state *st = iio_priv(indio_dev);
575 
576 	return sysfs_emit(buf, "%d\n", st->pwr_down);
577 }
578 
ad5758_write_powerdown(struct iio_dev * indio_dev,uintptr_t priv,struct iio_chan_spec const * chan,const char * buf,size_t len)579 static ssize_t ad5758_write_powerdown(struct iio_dev *indio_dev,
580 				      uintptr_t priv,
581 				      struct iio_chan_spec const *chan,
582 				      const char *buf, size_t len)
583 {
584 	struct ad5758_state *st = iio_priv(indio_dev);
585 	bool pwr_down;
586 	unsigned int dac_config_mode, val;
587 	unsigned long int dac_config_msk;
588 	int ret;
589 
590 	ret = kstrtobool(buf, &pwr_down);
591 	if (ret)
592 		return ret;
593 
594 	mutex_lock(&st->lock);
595 	if (pwr_down)
596 		val = 0;
597 	else
598 		val = 1;
599 
600 	dac_config_mode = AD5758_DAC_CONFIG_OUT_EN_MODE(val) |
601 			  AD5758_DAC_CONFIG_INT_EN_MODE(val);
602 	dac_config_msk = AD5758_DAC_CONFIG_OUT_EN_MSK |
603 			 AD5758_DAC_CONFIG_INT_EN_MSK;
604 
605 	ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
606 				    dac_config_msk,
607 				    dac_config_mode);
608 	if (ret < 0)
609 		goto err_unlock;
610 
611 	st->pwr_down = pwr_down;
612 
613 err_unlock:
614 	mutex_unlock(&st->lock);
615 
616 	return ret ? ret : len;
617 }
618 
619 static const struct iio_info ad5758_info = {
620 	.read_raw = ad5758_read_raw,
621 	.write_raw = ad5758_write_raw,
622 	.debugfs_reg_access = &ad5758_reg_access,
623 };
624 
625 static const struct iio_chan_spec_ext_info ad5758_ext_info[] = {
626 	{
627 		.name = "powerdown",
628 		.read = ad5758_read_powerdown,
629 		.write = ad5758_write_powerdown,
630 		.shared = IIO_SHARED_BY_TYPE,
631 	},
632 	{ }
633 };
634 
635 #define AD5758_DAC_CHAN(_chan_type) {				\
636 	.type = (_chan_type),					\
637 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_RAW) |	\
638 		BIT(IIO_CHAN_INFO_SCALE) |			\
639 		BIT(IIO_CHAN_INFO_OFFSET),			\
640 	.indexed = 1,						\
641 	.output = 1,						\
642 	.ext_info = ad5758_ext_info,				\
643 }
644 
645 static const struct iio_chan_spec ad5758_voltage_ch[] = {
646 	AD5758_DAC_CHAN(IIO_VOLTAGE)
647 };
648 
649 static const struct iio_chan_spec ad5758_current_ch[] = {
650 	AD5758_DAC_CHAN(IIO_CURRENT)
651 };
652 
ad5758_is_valid_mode(enum ad5758_dc_dc_mode mode)653 static bool ad5758_is_valid_mode(enum ad5758_dc_dc_mode mode)
654 {
655 	switch (mode) {
656 	case AD5758_DCDC_MODE_DPC_CURRENT:
657 	case AD5758_DCDC_MODE_DPC_VOLTAGE:
658 	case AD5758_DCDC_MODE_PPC_CURRENT:
659 		return true;
660 	default:
661 		return false;
662 	}
663 }
664 
ad5758_crc_disable(struct ad5758_state * st)665 static int ad5758_crc_disable(struct ad5758_state *st)
666 {
667 	unsigned int mask;
668 
669 	mask = (AD5758_WR_FLAG_MSK(AD5758_DIGITAL_DIAG_CONFIG) << 24) | 0x5C3A;
670 	st->d32[0] = cpu_to_be32(mask);
671 
672 	return spi_write(st->spi, &st->d32[0], 4);
673 }
674 
ad5758_find_out_range(struct ad5758_state * st,const struct ad5758_range * range,unsigned int size,int min,int max)675 static int ad5758_find_out_range(struct ad5758_state *st,
676 				 const struct ad5758_range *range,
677 				 unsigned int size,
678 				 int min, int max)
679 {
680 	int i;
681 
682 	for (i = 0; i < size; i++) {
683 		if ((min == range[i].min) && (max == range[i].max)) {
684 			st->out_range.reg = range[i].reg;
685 			st->out_range.min = range[i].min;
686 			st->out_range.max = range[i].max;
687 
688 			return 0;
689 		}
690 	}
691 
692 	return -EINVAL;
693 }
694 
ad5758_parse_dt(struct ad5758_state * st)695 static int ad5758_parse_dt(struct ad5758_state *st)
696 {
697 	unsigned int tmp, tmparray[2], size;
698 	const struct ad5758_range *range;
699 	int *index, ret;
700 
701 	st->dc_dc_ilim = 0;
702 	ret = device_property_read_u32(&st->spi->dev,
703 				       "adi,dc-dc-ilim-microamp", &tmp);
704 	if (ret) {
705 		dev_dbg(&st->spi->dev,
706 			"Missing \"dc-dc-ilim-microamp\" property\n");
707 	} else {
708 		index = bsearch(&tmp, ad5758_dc_dc_ilim,
709 				ARRAY_SIZE(ad5758_dc_dc_ilim),
710 				sizeof(int), cmpfunc);
711 		if (!index)
712 			dev_dbg(&st->spi->dev, "dc-dc-ilim out of range\n");
713 		else
714 			st->dc_dc_ilim = index - ad5758_dc_dc_ilim;
715 	}
716 
717 	ret = device_property_read_u32(&st->spi->dev, "adi,dc-dc-mode",
718 				       &st->dc_dc_mode);
719 	if (ret) {
720 		dev_err(&st->spi->dev, "Missing \"dc-dc-mode\" property\n");
721 		return ret;
722 	}
723 
724 	if (!ad5758_is_valid_mode(st->dc_dc_mode))
725 		return -EINVAL;
726 
727 	if (st->dc_dc_mode == AD5758_DCDC_MODE_DPC_VOLTAGE) {
728 		ret = device_property_read_u32_array(&st->spi->dev,
729 						     "adi,range-microvolt",
730 						     tmparray, 2);
731 		if (ret) {
732 			dev_err(&st->spi->dev,
733 				"Missing \"range-microvolt\" property\n");
734 			return ret;
735 		}
736 		range = ad5758_voltage_range;
737 		size = ARRAY_SIZE(ad5758_voltage_range);
738 	} else {
739 		ret = device_property_read_u32_array(&st->spi->dev,
740 						     "adi,range-microamp",
741 						     tmparray, 2);
742 		if (ret) {
743 			dev_err(&st->spi->dev,
744 				"Missing \"range-microamp\" property\n");
745 			return ret;
746 		}
747 		range = ad5758_current_range;
748 		size = ARRAY_SIZE(ad5758_current_range);
749 	}
750 
751 	ret = ad5758_find_out_range(st, range, size, tmparray[0], tmparray[1]);
752 	if (ret) {
753 		dev_err(&st->spi->dev, "range invalid\n");
754 		return ret;
755 	}
756 
757 	ret = device_property_read_u32(&st->spi->dev, "adi,slew-time-us", &tmp);
758 	if (ret) {
759 		dev_dbg(&st->spi->dev, "Missing \"slew-time-us\" property\n");
760 		st->slew_time = 0;
761 	} else {
762 		st->slew_time = tmp;
763 	}
764 
765 	return 0;
766 }
767 
ad5758_init(struct ad5758_state * st)768 static int ad5758_init(struct ad5758_state *st)
769 {
770 	int regval, ret;
771 
772 	st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
773 						 GPIOD_OUT_HIGH);
774 	if (IS_ERR(st->gpio_reset))
775 		return PTR_ERR(st->gpio_reset);
776 
777 	/* Disable CRC checks */
778 	ret = ad5758_crc_disable(st);
779 	if (ret < 0)
780 		return ret;
781 
782 	/* Perform a reset */
783 	ret = ad5758_reset(st);
784 	if (ret < 0)
785 		return ret;
786 
787 	/* Disable CRC checks */
788 	ret = ad5758_crc_disable(st);
789 	if (ret < 0)
790 		return ret;
791 
792 	/* Perform a calibration memory refresh */
793 	ret = ad5758_calib_mem_refresh(st);
794 	if (ret < 0)
795 		return ret;
796 
797 	regval = ad5758_spi_reg_read(st, AD5758_DIGITAL_DIAG_RESULTS);
798 	if (regval < 0)
799 		return regval;
800 
801 	/* Clear all the error flags */
802 	ret = ad5758_spi_reg_write(st, AD5758_DIGITAL_DIAG_RESULTS, regval);
803 	if (ret < 0)
804 		return ret;
805 
806 	/* Set the dc-to-dc current limit */
807 	ret = ad5758_set_dc_dc_ilim(st, st->dc_dc_ilim);
808 	if (ret < 0)
809 		return ret;
810 
811 	/* Configure the dc-to-dc controller mode */
812 	ret = ad5758_set_dc_dc_conv_mode(st, st->dc_dc_mode);
813 	if (ret < 0)
814 		return ret;
815 
816 	/* Configure the output range */
817 	ret = ad5758_set_out_range(st, st->out_range.reg);
818 	if (ret < 0)
819 		return ret;
820 
821 	/* Enable Slew Rate Control, set the slew rate clock and step */
822 	if (st->slew_time) {
823 		ret = ad5758_slew_rate_config(st);
824 		if (ret < 0)
825 			return ret;
826 	}
827 
828 	/* Power up the DAC and internal (INT) amplifiers */
829 	ret = ad5758_internal_buffers_en(st, 1);
830 	if (ret < 0)
831 		return ret;
832 
833 	/* Enable VIOUT */
834 	return ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
835 				     AD5758_DAC_CONFIG_OUT_EN_MSK,
836 				     AD5758_DAC_CONFIG_OUT_EN_MODE(1));
837 }
838 
ad5758_probe(struct spi_device * spi)839 static int ad5758_probe(struct spi_device *spi)
840 {
841 	struct ad5758_state *st;
842 	struct iio_dev *indio_dev;
843 	int ret;
844 
845 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
846 	if (!indio_dev)
847 		return -ENOMEM;
848 
849 	st = iio_priv(indio_dev);
850 	spi_set_drvdata(spi, indio_dev);
851 
852 	st->spi = spi;
853 
854 	mutex_init(&st->lock);
855 
856 	indio_dev->name = spi_get_device_id(spi)->name;
857 	indio_dev->info = &ad5758_info;
858 	indio_dev->modes = INDIO_DIRECT_MODE;
859 	indio_dev->num_channels = 1;
860 
861 	ret = ad5758_parse_dt(st);
862 	if (ret < 0)
863 		return ret;
864 
865 	if (st->dc_dc_mode == AD5758_DCDC_MODE_DPC_VOLTAGE)
866 		indio_dev->channels = ad5758_voltage_ch;
867 	else
868 		indio_dev->channels = ad5758_current_ch;
869 
870 	ret = ad5758_init(st);
871 	if (ret < 0) {
872 		dev_err(&spi->dev, "AD5758 init failed\n");
873 		return ret;
874 	}
875 
876 	return devm_iio_device_register(&st->spi->dev, indio_dev);
877 }
878 
879 static const struct spi_device_id ad5758_id[] = {
880 	{ "ad5758", 0 },
881 	{}
882 };
883 MODULE_DEVICE_TABLE(spi, ad5758_id);
884 
885 static const struct of_device_id ad5758_of_match[] = {
886         { .compatible = "adi,ad5758" },
887         { },
888 };
889 MODULE_DEVICE_TABLE(of, ad5758_of_match);
890 
891 static struct spi_driver ad5758_driver = {
892 	.driver = {
893 		.name = KBUILD_MODNAME,
894 		.of_match_table = ad5758_of_match,
895 	},
896 	.probe = ad5758_probe,
897 	.id_table = ad5758_id,
898 };
899 
900 module_spi_driver(ad5758_driver);
901 
902 MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
903 MODULE_DESCRIPTION("Analog Devices AD5758 DAC");
904 MODULE_LICENSE("GPL v2");
905