xref: /openbmc/linux/drivers/iio/adc/ad7192.c (revision b625fe69)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * AD7190 AD7192 AD7193 AD7195 SPI ADC driver
4  *
5  * Copyright 2011-2015 Analog Devices Inc.
6  */
7 
8 #include <linux/interrupt.h>
9 #include <linux/clk.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
14 #include <linux/spi/spi.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/err.h>
17 #include <linux/sched.h>
18 #include <linux/delay.h>
19 #include <linux/of_device.h>
20 
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/buffer.h>
24 #include <linux/iio/trigger.h>
25 #include <linux/iio/trigger_consumer.h>
26 #include <linux/iio/triggered_buffer.h>
27 #include <linux/iio/adc/ad_sigma_delta.h>
28 
29 /* Registers */
30 #define AD7192_REG_COMM		0 /* Communications Register (WO, 8-bit) */
31 #define AD7192_REG_STAT		0 /* Status Register	     (RO, 8-bit) */
32 #define AD7192_REG_MODE		1 /* Mode Register	     (RW, 24-bit */
33 #define AD7192_REG_CONF		2 /* Configuration Register  (RW, 24-bit) */
34 #define AD7192_REG_DATA		3 /* Data Register	     (RO, 24/32-bit) */
35 #define AD7192_REG_ID		4 /* ID Register	     (RO, 8-bit) */
36 #define AD7192_REG_GPOCON	5 /* GPOCON Register	     (RO, 8-bit) */
37 #define AD7192_REG_OFFSET	6 /* Offset Register	     (RW, 16-bit */
38 				  /* (AD7792)/24-bit (AD7192)) */
39 #define AD7192_REG_FULLSALE	7 /* Full-Scale Register */
40 				  /* (RW, 16-bit (AD7792)/24-bit (AD7192)) */
41 
42 /* Communications Register Bit Designations (AD7192_REG_COMM) */
43 #define AD7192_COMM_WEN		BIT(7) /* Write Enable */
44 #define AD7192_COMM_WRITE	0 /* Write Operation */
45 #define AD7192_COMM_READ	BIT(6) /* Read Operation */
46 #define AD7192_COMM_ADDR(x)	(((x) & 0x7) << 3) /* Register Address */
47 #define AD7192_COMM_CREAD	BIT(2) /* Continuous Read of Data Register */
48 
49 /* Status Register Bit Designations (AD7192_REG_STAT) */
50 #define AD7192_STAT_RDY		BIT(7) /* Ready */
51 #define AD7192_STAT_ERR		BIT(6) /* Error (Overrange, Underrange) */
52 #define AD7192_STAT_NOREF	BIT(5) /* Error no external reference */
53 #define AD7192_STAT_PARITY	BIT(4) /* Parity */
54 #define AD7192_STAT_CH3		BIT(2) /* Channel 3 */
55 #define AD7192_STAT_CH2		BIT(1) /* Channel 2 */
56 #define AD7192_STAT_CH1		BIT(0) /* Channel 1 */
57 
58 /* Mode Register Bit Designations (AD7192_REG_MODE) */
59 #define AD7192_MODE_SEL(x)	(((x) & 0x7) << 21) /* Operation Mode Select */
60 #define AD7192_MODE_SEL_MASK	(0x7 << 21) /* Operation Mode Select Mask */
61 #define AD7192_MODE_DAT_STA	BIT(20) /* Status Register transmission */
62 #define AD7192_MODE_CLKSRC(x)	(((x) & 0x3) << 18) /* Clock Source Select */
63 #define AD7192_MODE_SINC3	BIT(15) /* SINC3 Filter Select */
64 #define AD7192_MODE_ACX		BIT(14) /* AC excitation enable(AD7195 only)*/
65 #define AD7192_MODE_ENPAR	BIT(13) /* Parity Enable */
66 #define AD7192_MODE_CLKDIV	BIT(12) /* Clock divide by 2 (AD7190/2 only)*/
67 #define AD7192_MODE_SCYCLE	BIT(11) /* Single cycle conversion */
68 #define AD7192_MODE_REJ60	BIT(10) /* 50/60Hz notch filter */
69 #define AD7192_MODE_RATE(x)	((x) & 0x3FF) /* Filter Update Rate Select */
70 
71 /* Mode Register: AD7192_MODE_SEL options */
72 #define AD7192_MODE_CONT		0 /* Continuous Conversion Mode */
73 #define AD7192_MODE_SINGLE		1 /* Single Conversion Mode */
74 #define AD7192_MODE_IDLE		2 /* Idle Mode */
75 #define AD7192_MODE_PWRDN		3 /* Power-Down Mode */
76 #define AD7192_MODE_CAL_INT_ZERO	4 /* Internal Zero-Scale Calibration */
77 #define AD7192_MODE_CAL_INT_FULL	5 /* Internal Full-Scale Calibration */
78 #define AD7192_MODE_CAL_SYS_ZERO	6 /* System Zero-Scale Calibration */
79 #define AD7192_MODE_CAL_SYS_FULL	7 /* System Full-Scale Calibration */
80 
81 /* Mode Register: AD7192_MODE_CLKSRC options */
82 #define AD7192_CLK_EXT_MCLK1_2		0 /* External 4.92 MHz Clock connected*/
83 					  /* from MCLK1 to MCLK2 */
84 #define AD7192_CLK_EXT_MCLK2		1 /* External Clock applied to MCLK2 */
85 #define AD7192_CLK_INT			2 /* Internal 4.92 MHz Clock not */
86 					  /* available at the MCLK2 pin */
87 #define AD7192_CLK_INT_CO		3 /* Internal 4.92 MHz Clock available*/
88 					  /* at the MCLK2 pin */
89 
90 /* Configuration Register Bit Designations (AD7192_REG_CONF) */
91 
92 #define AD7192_CONF_CHOP	BIT(23) /* CHOP enable */
93 #define AD7192_CONF_REFSEL	BIT(20) /* REFIN1/REFIN2 Reference Select */
94 #define AD7192_CONF_CHAN(x)	((x) << 8) /* Channel select */
95 #define AD7192_CONF_CHAN_MASK	(0x7FF << 8) /* Channel select mask */
96 #define AD7192_CONF_BURN	BIT(7) /* Burnout current enable */
97 #define AD7192_CONF_REFDET	BIT(6) /* Reference detect enable */
98 #define AD7192_CONF_BUF		BIT(4) /* Buffered Mode Enable */
99 #define AD7192_CONF_UNIPOLAR	BIT(3) /* Unipolar/Bipolar Enable */
100 #define AD7192_CONF_GAIN(x)	((x) & 0x7) /* Gain Select */
101 
102 #define AD7192_CH_AIN1P_AIN2M	BIT(0) /* AIN1(+) - AIN2(-) */
103 #define AD7192_CH_AIN3P_AIN4M	BIT(1) /* AIN3(+) - AIN4(-) */
104 #define AD7192_CH_TEMP		BIT(2) /* Temp Sensor */
105 #define AD7192_CH_AIN2P_AIN2M	BIT(3) /* AIN2(+) - AIN2(-) */
106 #define AD7192_CH_AIN1		BIT(4) /* AIN1 - AINCOM */
107 #define AD7192_CH_AIN2		BIT(5) /* AIN2 - AINCOM */
108 #define AD7192_CH_AIN3		BIT(6) /* AIN3 - AINCOM */
109 #define AD7192_CH_AIN4		BIT(7) /* AIN4 - AINCOM */
110 
111 #define AD7193_CH_AIN1P_AIN2M	0x001  /* AIN1(+) - AIN2(-) */
112 #define AD7193_CH_AIN3P_AIN4M	0x002  /* AIN3(+) - AIN4(-) */
113 #define AD7193_CH_AIN5P_AIN6M	0x004  /* AIN5(+) - AIN6(-) */
114 #define AD7193_CH_AIN7P_AIN8M	0x008  /* AIN7(+) - AIN8(-) */
115 #define AD7193_CH_TEMP		0x100 /* Temp senseor */
116 #define AD7193_CH_AIN2P_AIN2M	0x200 /* AIN2(+) - AIN2(-) */
117 #define AD7193_CH_AIN1		0x401 /* AIN1 - AINCOM */
118 #define AD7193_CH_AIN2		0x402 /* AIN2 - AINCOM */
119 #define AD7193_CH_AIN3		0x404 /* AIN3 - AINCOM */
120 #define AD7193_CH_AIN4		0x408 /* AIN4 - AINCOM */
121 #define AD7193_CH_AIN5		0x410 /* AIN5 - AINCOM */
122 #define AD7193_CH_AIN6		0x420 /* AIN6 - AINCOM */
123 #define AD7193_CH_AIN7		0x440 /* AIN7 - AINCOM */
124 #define AD7193_CH_AIN8		0x480 /* AIN7 - AINCOM */
125 #define AD7193_CH_AINCOM	0x600 /* AINCOM - AINCOM */
126 
127 /* ID Register Bit Designations (AD7192_REG_ID) */
128 #define CHIPID_AD7190		0x4
129 #define CHIPID_AD7192		0x0
130 #define CHIPID_AD7193		0x2
131 #define CHIPID_AD7195		0x6
132 #define AD7192_ID_MASK		0x0F
133 
134 /* GPOCON Register Bit Designations (AD7192_REG_GPOCON) */
135 #define AD7192_GPOCON_BPDSW	BIT(6) /* Bridge power-down switch enable */
136 #define AD7192_GPOCON_GP32EN	BIT(5) /* Digital Output P3 and P2 enable */
137 #define AD7192_GPOCON_GP10EN	BIT(4) /* Digital Output P1 and P0 enable */
138 #define AD7192_GPOCON_P3DAT	BIT(3) /* P3 state */
139 #define AD7192_GPOCON_P2DAT	BIT(2) /* P2 state */
140 #define AD7192_GPOCON_P1DAT	BIT(1) /* P1 state */
141 #define AD7192_GPOCON_P0DAT	BIT(0) /* P0 state */
142 
143 #define AD7192_EXT_FREQ_MHZ_MIN	2457600
144 #define AD7192_EXT_FREQ_MHZ_MAX	5120000
145 #define AD7192_INT_FREQ_MHZ	4915200
146 
147 #define AD7192_NO_SYNC_FILTER	1
148 #define AD7192_SYNC3_FILTER	3
149 #define AD7192_SYNC4_FILTER	4
150 
151 /* NOTE:
152  * The AD7190/2/5 features a dual use data out ready DOUT/RDY output.
153  * In order to avoid contentions on the SPI bus, it's therefore necessary
154  * to use spi bus locking.
155  *
156  * The DOUT/RDY output must also be wired to an interrupt capable GPIO.
157  */
158 
159 enum {
160 	AD7192_SYSCALIB_ZERO_SCALE,
161 	AD7192_SYSCALIB_FULL_SCALE,
162 };
163 
164 enum {
165 	ID_AD7190,
166 	ID_AD7192,
167 	ID_AD7193,
168 	ID_AD7195,
169 };
170 
171 struct ad7192_chip_info {
172 	unsigned int			chip_id;
173 	const char			*name;
174 };
175 
176 struct ad7192_state {
177 	const struct ad7192_chip_info	*chip_info;
178 	struct regulator		*avdd;
179 	struct regulator		*dvdd;
180 	struct clk			*mclk;
181 	u16				int_vref_mv;
182 	u32				fclk;
183 	u32				f_order;
184 	u32				mode;
185 	u32				conf;
186 	u32				scale_avail[8][2];
187 	u8				gpocon;
188 	u8				clock_sel;
189 	struct mutex			lock;	/* protect sensor state */
190 	u8				syscalib_mode[8];
191 
192 	struct ad_sigma_delta		sd;
193 };
194 
195 static const char * const ad7192_syscalib_modes[] = {
196 	[AD7192_SYSCALIB_ZERO_SCALE] = "zero_scale",
197 	[AD7192_SYSCALIB_FULL_SCALE] = "full_scale",
198 };
199 
200 static int ad7192_set_syscalib_mode(struct iio_dev *indio_dev,
201 				    const struct iio_chan_spec *chan,
202 				    unsigned int mode)
203 {
204 	struct ad7192_state *st = iio_priv(indio_dev);
205 
206 	st->syscalib_mode[chan->channel] = mode;
207 
208 	return 0;
209 }
210 
211 static int ad7192_get_syscalib_mode(struct iio_dev *indio_dev,
212 				    const struct iio_chan_spec *chan)
213 {
214 	struct ad7192_state *st = iio_priv(indio_dev);
215 
216 	return st->syscalib_mode[chan->channel];
217 }
218 
219 static ssize_t ad7192_write_syscalib(struct iio_dev *indio_dev,
220 				     uintptr_t private,
221 				     const struct iio_chan_spec *chan,
222 				     const char *buf, size_t len)
223 {
224 	struct ad7192_state *st = iio_priv(indio_dev);
225 	bool sys_calib;
226 	int ret, temp;
227 
228 	ret = strtobool(buf, &sys_calib);
229 	if (ret)
230 		return ret;
231 
232 	temp = st->syscalib_mode[chan->channel];
233 	if (sys_calib) {
234 		if (temp == AD7192_SYSCALIB_ZERO_SCALE)
235 			ret = ad_sd_calibrate(&st->sd, AD7192_MODE_CAL_SYS_ZERO,
236 					      chan->address);
237 		else
238 			ret = ad_sd_calibrate(&st->sd, AD7192_MODE_CAL_SYS_FULL,
239 					      chan->address);
240 	}
241 
242 	return ret ? ret : len;
243 }
244 
245 static const struct iio_enum ad7192_syscalib_mode_enum = {
246 	.items = ad7192_syscalib_modes,
247 	.num_items = ARRAY_SIZE(ad7192_syscalib_modes),
248 	.set = ad7192_set_syscalib_mode,
249 	.get = ad7192_get_syscalib_mode
250 };
251 
252 static const struct iio_chan_spec_ext_info ad7192_calibsys_ext_info[] = {
253 	{
254 		.name = "sys_calibration",
255 		.write = ad7192_write_syscalib,
256 		.shared = IIO_SEPARATE,
257 	},
258 	IIO_ENUM("sys_calibration_mode", IIO_SEPARATE,
259 		 &ad7192_syscalib_mode_enum),
260 	IIO_ENUM_AVAILABLE("sys_calibration_mode", IIO_SHARED_BY_TYPE,
261 			   &ad7192_syscalib_mode_enum),
262 	{}
263 };
264 
265 static struct ad7192_state *ad_sigma_delta_to_ad7192(struct ad_sigma_delta *sd)
266 {
267 	return container_of(sd, struct ad7192_state, sd);
268 }
269 
270 static int ad7192_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
271 {
272 	struct ad7192_state *st = ad_sigma_delta_to_ad7192(sd);
273 
274 	st->conf &= ~AD7192_CONF_CHAN_MASK;
275 	st->conf |= AD7192_CONF_CHAN(channel);
276 
277 	return ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
278 }
279 
280 static int ad7192_set_mode(struct ad_sigma_delta *sd,
281 			   enum ad_sigma_delta_mode mode)
282 {
283 	struct ad7192_state *st = ad_sigma_delta_to_ad7192(sd);
284 
285 	st->mode &= ~AD7192_MODE_SEL_MASK;
286 	st->mode |= AD7192_MODE_SEL(mode);
287 
288 	return ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
289 }
290 
291 static const struct ad_sigma_delta_info ad7192_sigma_delta_info = {
292 	.set_channel = ad7192_set_channel,
293 	.set_mode = ad7192_set_mode,
294 	.has_registers = true,
295 	.addr_shift = 3,
296 	.read_mask = BIT(6),
297 	.irq_flags = IRQF_TRIGGER_FALLING,
298 };
299 
300 static const struct ad_sd_calib_data ad7192_calib_arr[8] = {
301 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN1},
302 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN1},
303 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN2},
304 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN2},
305 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN3},
306 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN3},
307 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN4},
308 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN4}
309 };
310 
311 static int ad7192_calibrate_all(struct ad7192_state *st)
312 {
313 	return ad_sd_calibrate_all(&st->sd, ad7192_calib_arr,
314 				   ARRAY_SIZE(ad7192_calib_arr));
315 }
316 
317 static inline bool ad7192_valid_external_frequency(u32 freq)
318 {
319 	return (freq >= AD7192_EXT_FREQ_MHZ_MIN &&
320 		freq <= AD7192_EXT_FREQ_MHZ_MAX);
321 }
322 
323 static int ad7192_of_clock_select(struct ad7192_state *st)
324 {
325 	struct device_node *np = st->sd.spi->dev.of_node;
326 	unsigned int clock_sel;
327 
328 	clock_sel = AD7192_CLK_INT;
329 
330 	/* use internal clock */
331 	if (st->mclk) {
332 		if (of_property_read_bool(np, "adi,int-clock-output-enable"))
333 			clock_sel = AD7192_CLK_INT_CO;
334 	} else {
335 		if (of_property_read_bool(np, "adi,clock-xtal"))
336 			clock_sel = AD7192_CLK_EXT_MCLK1_2;
337 		else
338 			clock_sel = AD7192_CLK_EXT_MCLK2;
339 	}
340 
341 	return clock_sel;
342 }
343 
344 static int ad7192_setup(struct ad7192_state *st, struct device_node *np)
345 {
346 	struct iio_dev *indio_dev = spi_get_drvdata(st->sd.spi);
347 	bool rej60_en, refin2_en;
348 	bool buf_en, bipolar, burnout_curr_en;
349 	unsigned long long scale_uv;
350 	int i, ret, id;
351 
352 	/* reset the serial interface */
353 	ret = ad_sd_reset(&st->sd, 48);
354 	if (ret < 0)
355 		return ret;
356 	usleep_range(500, 1000); /* Wait for at least 500us */
357 
358 	/* write/read test for device presence */
359 	ret = ad_sd_read_reg(&st->sd, AD7192_REG_ID, 1, &id);
360 	if (ret)
361 		return ret;
362 
363 	id &= AD7192_ID_MASK;
364 
365 	if (id != st->chip_info->chip_id)
366 		dev_warn(&st->sd.spi->dev, "device ID query failed (0x%X)\n",
367 			 id);
368 
369 	st->mode = AD7192_MODE_SEL(AD7192_MODE_IDLE) |
370 		AD7192_MODE_CLKSRC(st->clock_sel) |
371 		AD7192_MODE_RATE(480);
372 
373 	st->conf = AD7192_CONF_GAIN(0);
374 
375 	rej60_en = of_property_read_bool(np, "adi,rejection-60-Hz-enable");
376 	if (rej60_en)
377 		st->mode |= AD7192_MODE_REJ60;
378 
379 	refin2_en = of_property_read_bool(np, "adi,refin2-pins-enable");
380 	if (refin2_en && st->chip_info->chip_id != CHIPID_AD7195)
381 		st->conf |= AD7192_CONF_REFSEL;
382 
383 	st->conf &= ~AD7192_CONF_CHOP;
384 	st->f_order = AD7192_NO_SYNC_FILTER;
385 
386 	buf_en = of_property_read_bool(np, "adi,buffer-enable");
387 	if (buf_en)
388 		st->conf |= AD7192_CONF_BUF;
389 
390 	bipolar = of_property_read_bool(np, "bipolar");
391 	if (!bipolar)
392 		st->conf |= AD7192_CONF_UNIPOLAR;
393 
394 	burnout_curr_en = of_property_read_bool(np,
395 						"adi,burnout-currents-enable");
396 	if (burnout_curr_en && buf_en) {
397 		st->conf |= AD7192_CONF_BURN;
398 	} else if (burnout_curr_en) {
399 		dev_warn(&st->sd.spi->dev,
400 			 "Can't enable burnout currents: see CHOP or buffer\n");
401 	}
402 
403 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
404 	if (ret)
405 		return ret;
406 
407 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
408 	if (ret)
409 		return ret;
410 
411 	ret = ad7192_calibrate_all(st);
412 	if (ret)
413 		return ret;
414 
415 	/* Populate available ADC input ranges */
416 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
417 		scale_uv = ((u64)st->int_vref_mv * 100000000)
418 			>> (indio_dev->channels[0].scan_type.realbits -
419 			((st->conf & AD7192_CONF_UNIPOLAR) ? 0 : 1));
420 		scale_uv >>= i;
421 
422 		st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
423 		st->scale_avail[i][0] = scale_uv;
424 	}
425 
426 	return 0;
427 }
428 
429 static ssize_t ad7192_show_ac_excitation(struct device *dev,
430 					 struct device_attribute *attr,
431 					 char *buf)
432 {
433 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
434 	struct ad7192_state *st = iio_priv(indio_dev);
435 
436 	return sprintf(buf, "%d\n", !!(st->mode & AD7192_MODE_ACX));
437 }
438 
439 static ssize_t ad7192_show_bridge_switch(struct device *dev,
440 					 struct device_attribute *attr,
441 					 char *buf)
442 {
443 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
444 	struct ad7192_state *st = iio_priv(indio_dev);
445 
446 	return sprintf(buf, "%d\n", !!(st->gpocon & AD7192_GPOCON_BPDSW));
447 }
448 
449 static ssize_t ad7192_set(struct device *dev,
450 			  struct device_attribute *attr,
451 			  const char *buf,
452 			  size_t len)
453 {
454 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
455 	struct ad7192_state *st = iio_priv(indio_dev);
456 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
457 	int ret;
458 	bool val;
459 
460 	ret = strtobool(buf, &val);
461 	if (ret < 0)
462 		return ret;
463 
464 	ret = iio_device_claim_direct_mode(indio_dev);
465 	if (ret)
466 		return ret;
467 
468 	switch ((u32)this_attr->address) {
469 	case AD7192_REG_GPOCON:
470 		if (val)
471 			st->gpocon |= AD7192_GPOCON_BPDSW;
472 		else
473 			st->gpocon &= ~AD7192_GPOCON_BPDSW;
474 
475 		ad_sd_write_reg(&st->sd, AD7192_REG_GPOCON, 1, st->gpocon);
476 		break;
477 	case AD7192_REG_MODE:
478 		if (val)
479 			st->mode |= AD7192_MODE_ACX;
480 		else
481 			st->mode &= ~AD7192_MODE_ACX;
482 
483 		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
484 		break;
485 	default:
486 		ret = -EINVAL;
487 	}
488 
489 	iio_device_release_direct_mode(indio_dev);
490 
491 	return ret ? ret : len;
492 }
493 
494 static void ad7192_get_available_filter_freq(struct ad7192_state *st,
495 						    int *freq)
496 {
497 	unsigned int fadc;
498 
499 	/* Formulas for filter at page 25 of the datasheet */
500 	fadc = DIV_ROUND_CLOSEST(st->fclk,
501 				 AD7192_SYNC4_FILTER * AD7192_MODE_RATE(st->mode));
502 	freq[0] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
503 
504 	fadc = DIV_ROUND_CLOSEST(st->fclk,
505 				 AD7192_SYNC3_FILTER * AD7192_MODE_RATE(st->mode));
506 	freq[1] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
507 
508 	fadc = DIV_ROUND_CLOSEST(st->fclk, AD7192_MODE_RATE(st->mode));
509 	freq[2] = DIV_ROUND_CLOSEST(fadc * 230, 1024);
510 	freq[3] = DIV_ROUND_CLOSEST(fadc * 272, 1024);
511 }
512 
513 static ssize_t ad7192_show_filter_avail(struct device *dev,
514 					struct device_attribute *attr,
515 					char *buf)
516 {
517 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
518 	struct ad7192_state *st = iio_priv(indio_dev);
519 	unsigned int freq_avail[4], i;
520 	size_t len = 0;
521 
522 	ad7192_get_available_filter_freq(st, freq_avail);
523 
524 	for (i = 0; i < ARRAY_SIZE(freq_avail); i++)
525 		len += scnprintf(buf + len, PAGE_SIZE - len,
526 				 "%d.%d ", freq_avail[i] / 1000,
527 				 freq_avail[i] % 1000);
528 
529 	buf[len - 1] = '\n';
530 
531 	return len;
532 }
533 
534 static IIO_DEVICE_ATTR(filter_low_pass_3db_frequency_available,
535 		       0444, ad7192_show_filter_avail, NULL, 0);
536 
537 static IIO_DEVICE_ATTR(bridge_switch_en, 0644,
538 		       ad7192_show_bridge_switch, ad7192_set,
539 		       AD7192_REG_GPOCON);
540 
541 static IIO_DEVICE_ATTR(ac_excitation_en, 0644,
542 		       ad7192_show_ac_excitation, ad7192_set,
543 		       AD7192_REG_MODE);
544 
545 static struct attribute *ad7192_attributes[] = {
546 	&iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
547 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
548 	&iio_dev_attr_ac_excitation_en.dev_attr.attr,
549 	NULL
550 };
551 
552 static const struct attribute_group ad7192_attribute_group = {
553 	.attrs = ad7192_attributes,
554 };
555 
556 static struct attribute *ad7195_attributes[] = {
557 	&iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
558 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
559 	NULL
560 };
561 
562 static const struct attribute_group ad7195_attribute_group = {
563 	.attrs = ad7195_attributes,
564 };
565 
566 static unsigned int ad7192_get_temp_scale(bool unipolar)
567 {
568 	return unipolar ? 2815 * 2 : 2815;
569 }
570 
571 static int ad7192_set_3db_filter_freq(struct ad7192_state *st,
572 				      int val, int val2)
573 {
574 	int freq_avail[4], i, ret, freq;
575 	unsigned int diff_new, diff_old;
576 	int idx = 0;
577 
578 	diff_old = U32_MAX;
579 	freq = val * 1000 + val2;
580 
581 	ad7192_get_available_filter_freq(st, freq_avail);
582 
583 	for (i = 0; i < ARRAY_SIZE(freq_avail); i++) {
584 		diff_new = abs(freq - freq_avail[i]);
585 		if (diff_new < diff_old) {
586 			diff_old = diff_new;
587 			idx = i;
588 		}
589 	}
590 
591 	switch (idx) {
592 	case 0:
593 		st->f_order = AD7192_SYNC4_FILTER;
594 		st->mode &= ~AD7192_MODE_SINC3;
595 
596 		st->conf |= AD7192_CONF_CHOP;
597 		break;
598 	case 1:
599 		st->f_order = AD7192_SYNC3_FILTER;
600 		st->mode |= AD7192_MODE_SINC3;
601 
602 		st->conf |= AD7192_CONF_CHOP;
603 		break;
604 	case 2:
605 		st->f_order = AD7192_NO_SYNC_FILTER;
606 		st->mode &= ~AD7192_MODE_SINC3;
607 
608 		st->conf &= ~AD7192_CONF_CHOP;
609 		break;
610 	case 3:
611 		st->f_order = AD7192_NO_SYNC_FILTER;
612 		st->mode |= AD7192_MODE_SINC3;
613 
614 		st->conf &= ~AD7192_CONF_CHOP;
615 		break;
616 	}
617 
618 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
619 	if (ret < 0)
620 		return ret;
621 
622 	return ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
623 }
624 
625 static int ad7192_get_3db_filter_freq(struct ad7192_state *st)
626 {
627 	unsigned int fadc;
628 
629 	fadc = DIV_ROUND_CLOSEST(st->fclk,
630 				 st->f_order * AD7192_MODE_RATE(st->mode));
631 
632 	if (st->conf & AD7192_CONF_CHOP)
633 		return DIV_ROUND_CLOSEST(fadc * 240, 1024);
634 	if (st->mode & AD7192_MODE_SINC3)
635 		return DIV_ROUND_CLOSEST(fadc * 272, 1024);
636 	else
637 		return DIV_ROUND_CLOSEST(fadc * 230, 1024);
638 }
639 
640 static int ad7192_read_raw(struct iio_dev *indio_dev,
641 			   struct iio_chan_spec const *chan,
642 			   int *val,
643 			   int *val2,
644 			   long m)
645 {
646 	struct ad7192_state *st = iio_priv(indio_dev);
647 	bool unipolar = !!(st->conf & AD7192_CONF_UNIPOLAR);
648 
649 	switch (m) {
650 	case IIO_CHAN_INFO_RAW:
651 		return ad_sigma_delta_single_conversion(indio_dev, chan, val);
652 	case IIO_CHAN_INFO_SCALE:
653 		switch (chan->type) {
654 		case IIO_VOLTAGE:
655 			mutex_lock(&st->lock);
656 			*val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
657 			*val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
658 			mutex_unlock(&st->lock);
659 			return IIO_VAL_INT_PLUS_NANO;
660 		case IIO_TEMP:
661 			*val = 0;
662 			*val2 = 1000000000 / ad7192_get_temp_scale(unipolar);
663 			return IIO_VAL_INT_PLUS_NANO;
664 		default:
665 			return -EINVAL;
666 		}
667 	case IIO_CHAN_INFO_OFFSET:
668 		if (!unipolar)
669 			*val = -(1 << (chan->scan_type.realbits - 1));
670 		else
671 			*val = 0;
672 		/* Kelvin to Celsius */
673 		if (chan->type == IIO_TEMP)
674 			*val -= 273 * ad7192_get_temp_scale(unipolar);
675 		return IIO_VAL_INT;
676 	case IIO_CHAN_INFO_SAMP_FREQ:
677 		*val = st->fclk /
678 			(st->f_order * 1024 * AD7192_MODE_RATE(st->mode));
679 		return IIO_VAL_INT;
680 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
681 		*val = ad7192_get_3db_filter_freq(st);
682 		*val2 = 1000;
683 		return IIO_VAL_FRACTIONAL;
684 	}
685 
686 	return -EINVAL;
687 }
688 
689 static int ad7192_write_raw(struct iio_dev *indio_dev,
690 			    struct iio_chan_spec const *chan,
691 			    int val,
692 			    int val2,
693 			    long mask)
694 {
695 	struct ad7192_state *st = iio_priv(indio_dev);
696 	int ret, i, div;
697 	unsigned int tmp;
698 
699 	ret = iio_device_claim_direct_mode(indio_dev);
700 	if (ret)
701 		return ret;
702 
703 	switch (mask) {
704 	case IIO_CHAN_INFO_SCALE:
705 		ret = -EINVAL;
706 		mutex_lock(&st->lock);
707 		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
708 			if (val2 == st->scale_avail[i][1]) {
709 				ret = 0;
710 				tmp = st->conf;
711 				st->conf &= ~AD7192_CONF_GAIN(-1);
712 				st->conf |= AD7192_CONF_GAIN(i);
713 				if (tmp == st->conf)
714 					break;
715 				ad_sd_write_reg(&st->sd, AD7192_REG_CONF,
716 						3, st->conf);
717 				ad7192_calibrate_all(st);
718 				break;
719 			}
720 		mutex_unlock(&st->lock);
721 		break;
722 	case IIO_CHAN_INFO_SAMP_FREQ:
723 		if (!val) {
724 			ret = -EINVAL;
725 			break;
726 		}
727 
728 		div = st->fclk / (val * st->f_order * 1024);
729 		if (div < 1 || div > 1023) {
730 			ret = -EINVAL;
731 			break;
732 		}
733 
734 		st->mode &= ~AD7192_MODE_RATE(-1);
735 		st->mode |= AD7192_MODE_RATE(div);
736 		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
737 		break;
738 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
739 		ret = ad7192_set_3db_filter_freq(st, val, val2 / 1000);
740 		break;
741 	default:
742 		ret = -EINVAL;
743 	}
744 
745 	iio_device_release_direct_mode(indio_dev);
746 
747 	return ret;
748 }
749 
750 static int ad7192_write_raw_get_fmt(struct iio_dev *indio_dev,
751 				    struct iio_chan_spec const *chan,
752 				    long mask)
753 {
754 	switch (mask) {
755 	case IIO_CHAN_INFO_SCALE:
756 		return IIO_VAL_INT_PLUS_NANO;
757 	case IIO_CHAN_INFO_SAMP_FREQ:
758 		return IIO_VAL_INT;
759 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
760 		return IIO_VAL_INT_PLUS_MICRO;
761 	default:
762 		return -EINVAL;
763 	}
764 }
765 
766 static int ad7192_read_avail(struct iio_dev *indio_dev,
767 			     struct iio_chan_spec const *chan,
768 			     const int **vals, int *type, int *length,
769 			     long mask)
770 {
771 	struct ad7192_state *st = iio_priv(indio_dev);
772 
773 	switch (mask) {
774 	case IIO_CHAN_INFO_SCALE:
775 		*vals = (int *)st->scale_avail;
776 		*type = IIO_VAL_INT_PLUS_NANO;
777 		/* Values are stored in a 2D matrix  */
778 		*length = ARRAY_SIZE(st->scale_avail) * 2;
779 
780 		return IIO_AVAIL_LIST;
781 	}
782 
783 	return -EINVAL;
784 }
785 
786 static const struct iio_info ad7192_info = {
787 	.read_raw = ad7192_read_raw,
788 	.write_raw = ad7192_write_raw,
789 	.write_raw_get_fmt = ad7192_write_raw_get_fmt,
790 	.read_avail = ad7192_read_avail,
791 	.attrs = &ad7192_attribute_group,
792 	.validate_trigger = ad_sd_validate_trigger,
793 };
794 
795 static const struct iio_info ad7195_info = {
796 	.read_raw = ad7192_read_raw,
797 	.write_raw = ad7192_write_raw,
798 	.write_raw_get_fmt = ad7192_write_raw_get_fmt,
799 	.read_avail = ad7192_read_avail,
800 	.attrs = &ad7195_attribute_group,
801 	.validate_trigger = ad_sd_validate_trigger,
802 };
803 
804 #define __AD719x_CHANNEL(_si, _channel1, _channel2, _address, _extend_name, \
805 	_type, _mask_type_av, _ext_info) \
806 	{ \
807 		.type = (_type), \
808 		.differential = ((_channel2) == -1 ? 0 : 1), \
809 		.indexed = 1, \
810 		.channel = (_channel1), \
811 		.channel2 = (_channel2), \
812 		.address = (_address), \
813 		.extend_name = (_extend_name), \
814 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
815 			BIT(IIO_CHAN_INFO_OFFSET), \
816 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
817 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
818 			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
819 		.info_mask_shared_by_type_available = (_mask_type_av), \
820 		.ext_info = (_ext_info), \
821 		.scan_index = (_si), \
822 		.scan_type = { \
823 			.sign = 'u', \
824 			.realbits = 24, \
825 			.storagebits = 32, \
826 			.endianness = IIO_BE, \
827 		}, \
828 	}
829 
830 #define AD719x_DIFF_CHANNEL(_si, _channel1, _channel2, _address) \
831 	__AD719x_CHANNEL(_si, _channel1, _channel2, _address, NULL, \
832 		IIO_VOLTAGE, BIT(IIO_CHAN_INFO_SCALE), \
833 		ad7192_calibsys_ext_info)
834 
835 #define AD719x_CHANNEL(_si, _channel1, _address) \
836 	__AD719x_CHANNEL(_si, _channel1, -1, _address, NULL, IIO_VOLTAGE, \
837 		BIT(IIO_CHAN_INFO_SCALE), ad7192_calibsys_ext_info)
838 
839 #define AD719x_SHORTED_CHANNEL(_si, _channel1, _address) \
840 	__AD719x_CHANNEL(_si, _channel1, -1, _address, "shorted", IIO_VOLTAGE, \
841 		BIT(IIO_CHAN_INFO_SCALE), ad7192_calibsys_ext_info)
842 
843 #define AD719x_TEMP_CHANNEL(_si, _address) \
844 	__AD719x_CHANNEL(_si, 0, -1, _address, NULL, IIO_TEMP, 0, NULL)
845 
846 static const struct iio_chan_spec ad7192_channels[] = {
847 	AD719x_DIFF_CHANNEL(0, 1, 2, AD7192_CH_AIN1P_AIN2M),
848 	AD719x_DIFF_CHANNEL(1, 3, 4, AD7192_CH_AIN3P_AIN4M),
849 	AD719x_TEMP_CHANNEL(2, AD7192_CH_TEMP),
850 	AD719x_SHORTED_CHANNEL(3, 2, AD7192_CH_AIN2P_AIN2M),
851 	AD719x_CHANNEL(4, 1, AD7192_CH_AIN1),
852 	AD719x_CHANNEL(5, 2, AD7192_CH_AIN2),
853 	AD719x_CHANNEL(6, 3, AD7192_CH_AIN3),
854 	AD719x_CHANNEL(7, 4, AD7192_CH_AIN4),
855 	IIO_CHAN_SOFT_TIMESTAMP(8),
856 };
857 
858 static const struct iio_chan_spec ad7193_channels[] = {
859 	AD719x_DIFF_CHANNEL(0, 1, 2, AD7193_CH_AIN1P_AIN2M),
860 	AD719x_DIFF_CHANNEL(1, 3, 4, AD7193_CH_AIN3P_AIN4M),
861 	AD719x_DIFF_CHANNEL(2, 5, 6, AD7193_CH_AIN5P_AIN6M),
862 	AD719x_DIFF_CHANNEL(3, 7, 8, AD7193_CH_AIN7P_AIN8M),
863 	AD719x_TEMP_CHANNEL(4, AD7193_CH_TEMP),
864 	AD719x_SHORTED_CHANNEL(5, 2, AD7193_CH_AIN2P_AIN2M),
865 	AD719x_CHANNEL(6, 1, AD7193_CH_AIN1),
866 	AD719x_CHANNEL(7, 2, AD7193_CH_AIN2),
867 	AD719x_CHANNEL(8, 3, AD7193_CH_AIN3),
868 	AD719x_CHANNEL(9, 4, AD7193_CH_AIN4),
869 	AD719x_CHANNEL(10, 5, AD7193_CH_AIN5),
870 	AD719x_CHANNEL(11, 6, AD7193_CH_AIN6),
871 	AD719x_CHANNEL(12, 7, AD7193_CH_AIN7),
872 	AD719x_CHANNEL(13, 8, AD7193_CH_AIN8),
873 	IIO_CHAN_SOFT_TIMESTAMP(14),
874 };
875 
876 static const struct ad7192_chip_info ad7192_chip_info_tbl[] = {
877 	[ID_AD7190] = {
878 		.chip_id = CHIPID_AD7190,
879 		.name = "ad7190",
880 	},
881 	[ID_AD7192] = {
882 		.chip_id = CHIPID_AD7192,
883 		.name = "ad7192",
884 	},
885 	[ID_AD7193] = {
886 		.chip_id = CHIPID_AD7193,
887 		.name = "ad7193",
888 	},
889 	[ID_AD7195] = {
890 		.chip_id = CHIPID_AD7195,
891 		.name = "ad7195",
892 	},
893 };
894 
895 static int ad7192_channels_config(struct iio_dev *indio_dev)
896 {
897 	struct ad7192_state *st = iio_priv(indio_dev);
898 
899 	switch (st->chip_info->chip_id) {
900 	case CHIPID_AD7193:
901 		indio_dev->channels = ad7193_channels;
902 		indio_dev->num_channels = ARRAY_SIZE(ad7193_channels);
903 		break;
904 	default:
905 		indio_dev->channels = ad7192_channels;
906 		indio_dev->num_channels = ARRAY_SIZE(ad7192_channels);
907 		break;
908 	}
909 
910 	return 0;
911 }
912 
913 static void ad7192_reg_disable(void *reg)
914 {
915 	regulator_disable(reg);
916 }
917 
918 static void ad7192_clk_disable(void *clk)
919 {
920 	clk_disable_unprepare(clk);
921 }
922 
923 static int ad7192_probe(struct spi_device *spi)
924 {
925 	struct ad7192_state *st;
926 	struct iio_dev *indio_dev;
927 	int ret;
928 
929 	if (!spi->irq) {
930 		dev_err(&spi->dev, "no IRQ?\n");
931 		return -ENODEV;
932 	}
933 
934 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
935 	if (!indio_dev)
936 		return -ENOMEM;
937 
938 	st = iio_priv(indio_dev);
939 
940 	mutex_init(&st->lock);
941 
942 	st->avdd = devm_regulator_get(&spi->dev, "avdd");
943 	if (IS_ERR(st->avdd))
944 		return PTR_ERR(st->avdd);
945 
946 	ret = regulator_enable(st->avdd);
947 	if (ret) {
948 		dev_err(&spi->dev, "Failed to enable specified AVdd supply\n");
949 		return ret;
950 	}
951 
952 	ret = devm_add_action_or_reset(&spi->dev, ad7192_reg_disable, st->avdd);
953 	if (ret)
954 		return ret;
955 
956 	st->dvdd = devm_regulator_get(&spi->dev, "dvdd");
957 	if (IS_ERR(st->dvdd))
958 		return PTR_ERR(st->dvdd);
959 
960 	ret = regulator_enable(st->dvdd);
961 	if (ret) {
962 		dev_err(&spi->dev, "Failed to enable specified DVdd supply\n");
963 		return ret;
964 	}
965 
966 	ret = devm_add_action_or_reset(&spi->dev, ad7192_reg_disable, st->dvdd);
967 	if (ret)
968 		return ret;
969 
970 	ret = regulator_get_voltage(st->avdd);
971 	if (ret < 0) {
972 		dev_err(&spi->dev, "Device tree error, reference voltage undefined\n");
973 		return ret;
974 	}
975 	st->int_vref_mv = ret / 1000;
976 
977 	st->chip_info = of_device_get_match_data(&spi->dev);
978 	indio_dev->name = st->chip_info->name;
979 	indio_dev->modes = INDIO_DIRECT_MODE;
980 
981 	ret = ad7192_channels_config(indio_dev);
982 	if (ret < 0)
983 		return ret;
984 
985 	if (st->chip_info->chip_id == CHIPID_AD7195)
986 		indio_dev->info = &ad7195_info;
987 	else
988 		indio_dev->info = &ad7192_info;
989 
990 	ad_sd_init(&st->sd, indio_dev, spi, &ad7192_sigma_delta_info);
991 
992 	ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
993 	if (ret)
994 		return ret;
995 
996 	st->fclk = AD7192_INT_FREQ_MHZ;
997 
998 	st->mclk = devm_clk_get_optional(&spi->dev, "mclk");
999 	if (IS_ERR(st->mclk))
1000 		return PTR_ERR(st->mclk);
1001 
1002 	st->clock_sel = ad7192_of_clock_select(st);
1003 
1004 	if (st->clock_sel == AD7192_CLK_EXT_MCLK1_2 ||
1005 	    st->clock_sel == AD7192_CLK_EXT_MCLK2) {
1006 		ret = clk_prepare_enable(st->mclk);
1007 		if (ret < 0)
1008 			return ret;
1009 
1010 		ret = devm_add_action_or_reset(&spi->dev, ad7192_clk_disable,
1011 					       st->mclk);
1012 		if (ret)
1013 			return ret;
1014 
1015 		st->fclk = clk_get_rate(st->mclk);
1016 		if (!ad7192_valid_external_frequency(st->fclk)) {
1017 			dev_err(&spi->dev,
1018 				"External clock frequency out of bounds\n");
1019 			return -EINVAL;
1020 		}
1021 	}
1022 
1023 	ret = ad7192_setup(st, spi->dev.of_node);
1024 	if (ret)
1025 		return ret;
1026 
1027 	return devm_iio_device_register(&spi->dev, indio_dev);
1028 }
1029 
1030 static const struct of_device_id ad7192_of_match[] = {
1031 	{ .compatible = "adi,ad7190", .data = &ad7192_chip_info_tbl[ID_AD7190] },
1032 	{ .compatible = "adi,ad7192", .data = &ad7192_chip_info_tbl[ID_AD7192] },
1033 	{ .compatible = "adi,ad7193", .data = &ad7192_chip_info_tbl[ID_AD7193] },
1034 	{ .compatible = "adi,ad7195", .data = &ad7192_chip_info_tbl[ID_AD7195] },
1035 	{}
1036 };
1037 MODULE_DEVICE_TABLE(of, ad7192_of_match);
1038 
1039 static struct spi_driver ad7192_driver = {
1040 	.driver = {
1041 		.name	= "ad7192",
1042 		.of_match_table = ad7192_of_match,
1043 	},
1044 	.probe		= ad7192_probe,
1045 };
1046 module_spi_driver(ad7192_driver);
1047 
1048 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
1049 MODULE_DESCRIPTION("Analog Devices AD7190, AD7192, AD7193, AD7195 ADC");
1050 MODULE_LICENSE("GPL v2");
1051