xref: /openbmc/linux/drivers/iio/adc/ad7192.c (revision 55fd7e02)
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", &ad7192_syscalib_mode_enum),
261 	{}
262 };
263 
264 static struct ad7192_state *ad_sigma_delta_to_ad7192(struct ad_sigma_delta *sd)
265 {
266 	return container_of(sd, struct ad7192_state, sd);
267 }
268 
269 static int ad7192_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
270 {
271 	struct ad7192_state *st = ad_sigma_delta_to_ad7192(sd);
272 
273 	st->conf &= ~AD7192_CONF_CHAN_MASK;
274 	st->conf |= AD7192_CONF_CHAN(channel);
275 
276 	return ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
277 }
278 
279 static int ad7192_set_mode(struct ad_sigma_delta *sd,
280 			   enum ad_sigma_delta_mode mode)
281 {
282 	struct ad7192_state *st = ad_sigma_delta_to_ad7192(sd);
283 
284 	st->mode &= ~AD7192_MODE_SEL_MASK;
285 	st->mode |= AD7192_MODE_SEL(mode);
286 
287 	return ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
288 }
289 
290 static const struct ad_sigma_delta_info ad7192_sigma_delta_info = {
291 	.set_channel = ad7192_set_channel,
292 	.set_mode = ad7192_set_mode,
293 	.has_registers = true,
294 	.addr_shift = 3,
295 	.read_mask = BIT(6),
296 };
297 
298 static const struct ad_sd_calib_data ad7192_calib_arr[8] = {
299 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN1},
300 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN1},
301 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN2},
302 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN2},
303 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN3},
304 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN3},
305 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN4},
306 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN4}
307 };
308 
309 static int ad7192_calibrate_all(struct ad7192_state *st)
310 {
311 	return ad_sd_calibrate_all(&st->sd, ad7192_calib_arr,
312 				   ARRAY_SIZE(ad7192_calib_arr));
313 }
314 
315 static inline bool ad7192_valid_external_frequency(u32 freq)
316 {
317 	return (freq >= AD7192_EXT_FREQ_MHZ_MIN &&
318 		freq <= AD7192_EXT_FREQ_MHZ_MAX);
319 }
320 
321 static int ad7192_of_clock_select(struct ad7192_state *st)
322 {
323 	struct device_node *np = st->sd.spi->dev.of_node;
324 	unsigned int clock_sel;
325 
326 	clock_sel = AD7192_CLK_INT;
327 
328 	/* use internal clock */
329 	if (PTR_ERR(st->mclk) == -ENOENT) {
330 		if (of_property_read_bool(np, "adi,int-clock-output-enable"))
331 			clock_sel = AD7192_CLK_INT_CO;
332 	} else {
333 		if (of_property_read_bool(np, "adi,clock-xtal"))
334 			clock_sel = AD7192_CLK_EXT_MCLK1_2;
335 		else
336 			clock_sel = AD7192_CLK_EXT_MCLK2;
337 	}
338 
339 	return clock_sel;
340 }
341 
342 static int ad7192_setup(struct ad7192_state *st, struct device_node *np)
343 {
344 	struct iio_dev *indio_dev = spi_get_drvdata(st->sd.spi);
345 	bool rej60_en, refin2_en;
346 	bool buf_en, bipolar, burnout_curr_en;
347 	unsigned long long scale_uv;
348 	int i, ret, id;
349 
350 	/* reset the serial interface */
351 	ret = ad_sd_reset(&st->sd, 48);
352 	if (ret < 0)
353 		return ret;
354 	usleep_range(500, 1000); /* Wait for at least 500us */
355 
356 	/* write/read test for device presence */
357 	ret = ad_sd_read_reg(&st->sd, AD7192_REG_ID, 1, &id);
358 	if (ret)
359 		return ret;
360 
361 	id &= AD7192_ID_MASK;
362 
363 	if (id != st->chip_info->chip_id)
364 		dev_warn(&st->sd.spi->dev, "device ID query failed (0x%X)\n",
365 			 id);
366 
367 	st->mode = AD7192_MODE_SEL(AD7192_MODE_IDLE) |
368 		AD7192_MODE_CLKSRC(st->clock_sel) |
369 		AD7192_MODE_RATE(480);
370 
371 	st->conf = AD7192_CONF_GAIN(0);
372 
373 	rej60_en = of_property_read_bool(np, "adi,rejection-60-Hz-enable");
374 	if (rej60_en)
375 		st->mode |= AD7192_MODE_REJ60;
376 
377 	refin2_en = of_property_read_bool(np, "adi,refin2-pins-enable");
378 	if (refin2_en && st->chip_info->chip_id != CHIPID_AD7195)
379 		st->conf |= AD7192_CONF_REFSEL;
380 
381 	st->conf &= ~AD7192_CONF_CHOP;
382 	st->f_order = AD7192_NO_SYNC_FILTER;
383 
384 	buf_en = of_property_read_bool(np, "adi,buffer-enable");
385 	if (buf_en)
386 		st->conf |= AD7192_CONF_BUF;
387 
388 	bipolar = of_property_read_bool(np, "bipolar");
389 	if (!bipolar)
390 		st->conf |= AD7192_CONF_UNIPOLAR;
391 
392 	burnout_curr_en = of_property_read_bool(np,
393 						"adi,burnout-currents-enable");
394 	if (burnout_curr_en && buf_en) {
395 		st->conf |= AD7192_CONF_BURN;
396 	} else if (burnout_curr_en) {
397 		dev_warn(&st->sd.spi->dev,
398 			 "Can't enable burnout currents: see CHOP or buffer\n");
399 	}
400 
401 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
402 	if (ret)
403 		return ret;
404 
405 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
406 	if (ret)
407 		return ret;
408 
409 	ret = ad7192_calibrate_all(st);
410 	if (ret)
411 		return ret;
412 
413 	/* Populate available ADC input ranges */
414 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
415 		scale_uv = ((u64)st->int_vref_mv * 100000000)
416 			>> (indio_dev->channels[0].scan_type.realbits -
417 			((st->conf & AD7192_CONF_UNIPOLAR) ? 0 : 1));
418 		scale_uv >>= i;
419 
420 		st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
421 		st->scale_avail[i][0] = scale_uv;
422 	}
423 
424 	return 0;
425 }
426 
427 static ssize_t ad7192_show_ac_excitation(struct device *dev,
428 					 struct device_attribute *attr,
429 					 char *buf)
430 {
431 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
432 	struct ad7192_state *st = iio_priv(indio_dev);
433 
434 	return sprintf(buf, "%d\n", !!(st->mode & AD7192_MODE_ACX));
435 }
436 
437 static ssize_t ad7192_show_bridge_switch(struct device *dev,
438 					 struct device_attribute *attr,
439 					 char *buf)
440 {
441 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
442 	struct ad7192_state *st = iio_priv(indio_dev);
443 
444 	return sprintf(buf, "%d\n", !!(st->gpocon & AD7192_GPOCON_BPDSW));
445 }
446 
447 static ssize_t ad7192_set(struct device *dev,
448 			  struct device_attribute *attr,
449 			  const char *buf,
450 			  size_t len)
451 {
452 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
453 	struct ad7192_state *st = iio_priv(indio_dev);
454 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
455 	int ret;
456 	bool val;
457 
458 	ret = strtobool(buf, &val);
459 	if (ret < 0)
460 		return ret;
461 
462 	ret = iio_device_claim_direct_mode(indio_dev);
463 	if (ret)
464 		return ret;
465 
466 	switch ((u32)this_attr->address) {
467 	case AD7192_REG_GPOCON:
468 		if (val)
469 			st->gpocon |= AD7192_GPOCON_BPDSW;
470 		else
471 			st->gpocon &= ~AD7192_GPOCON_BPDSW;
472 
473 		ad_sd_write_reg(&st->sd, AD7192_REG_GPOCON, 1, st->gpocon);
474 		break;
475 	case AD7192_REG_MODE:
476 		if (val)
477 			st->mode |= AD7192_MODE_ACX;
478 		else
479 			st->mode &= ~AD7192_MODE_ACX;
480 
481 		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
482 		break;
483 	default:
484 		ret = -EINVAL;
485 	}
486 
487 	iio_device_release_direct_mode(indio_dev);
488 
489 	return ret ? ret : len;
490 }
491 
492 static void ad7192_get_available_filter_freq(struct ad7192_state *st,
493 						    int *freq)
494 {
495 	unsigned int fadc;
496 
497 	/* Formulas for filter at page 25 of the datasheet */
498 	fadc = DIV_ROUND_CLOSEST(st->fclk,
499 				 AD7192_SYNC4_FILTER * AD7192_MODE_RATE(st->mode));
500 	freq[0] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
501 
502 	fadc = DIV_ROUND_CLOSEST(st->fclk,
503 				 AD7192_SYNC3_FILTER * AD7192_MODE_RATE(st->mode));
504 	freq[1] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
505 
506 	fadc = DIV_ROUND_CLOSEST(st->fclk, AD7192_MODE_RATE(st->mode));
507 	freq[2] = DIV_ROUND_CLOSEST(fadc * 230, 1024);
508 	freq[3] = DIV_ROUND_CLOSEST(fadc * 272, 1024);
509 }
510 
511 static ssize_t ad7192_show_filter_avail(struct device *dev,
512 					struct device_attribute *attr,
513 					char *buf)
514 {
515 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
516 	struct ad7192_state *st = iio_priv(indio_dev);
517 	unsigned int freq_avail[4], i;
518 	size_t len = 0;
519 
520 	ad7192_get_available_filter_freq(st, freq_avail);
521 
522 	for (i = 0; i < ARRAY_SIZE(freq_avail); i++)
523 		len += scnprintf(buf + len, PAGE_SIZE - len,
524 				 "%d.%d ", freq_avail[i] / 1000,
525 				 freq_avail[i] % 1000);
526 
527 	buf[len - 1] = '\n';
528 
529 	return len;
530 }
531 
532 static IIO_DEVICE_ATTR(filter_low_pass_3db_frequency_available,
533 		       0444, ad7192_show_filter_avail, NULL, 0);
534 
535 static IIO_DEVICE_ATTR(bridge_switch_en, 0644,
536 		       ad7192_show_bridge_switch, ad7192_set,
537 		       AD7192_REG_GPOCON);
538 
539 static IIO_DEVICE_ATTR(ac_excitation_en, 0644,
540 		       ad7192_show_ac_excitation, ad7192_set,
541 		       AD7192_REG_MODE);
542 
543 static struct attribute *ad7192_attributes[] = {
544 	&iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
545 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
546 	&iio_dev_attr_ac_excitation_en.dev_attr.attr,
547 	NULL
548 };
549 
550 static const struct attribute_group ad7192_attribute_group = {
551 	.attrs = ad7192_attributes,
552 };
553 
554 static struct attribute *ad7195_attributes[] = {
555 	&iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
556 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
557 	NULL
558 };
559 
560 static const struct attribute_group ad7195_attribute_group = {
561 	.attrs = ad7195_attributes,
562 };
563 
564 static unsigned int ad7192_get_temp_scale(bool unipolar)
565 {
566 	return unipolar ? 2815 * 2 : 2815;
567 }
568 
569 static int ad7192_set_3db_filter_freq(struct ad7192_state *st,
570 				      int val, int val2)
571 {
572 	int freq_avail[4], i, ret, freq;
573 	unsigned int diff_new, diff_old;
574 	int idx = 0;
575 
576 	diff_old = U32_MAX;
577 	freq = val * 1000 + val2;
578 
579 	ad7192_get_available_filter_freq(st, freq_avail);
580 
581 	for (i = 0; i < ARRAY_SIZE(freq_avail); i++) {
582 		diff_new = abs(freq - freq_avail[i]);
583 		if (diff_new < diff_old) {
584 			diff_old = diff_new;
585 			idx = i;
586 		}
587 	}
588 
589 	switch (idx) {
590 	case 0:
591 		st->f_order = AD7192_SYNC4_FILTER;
592 		st->mode &= ~AD7192_MODE_SINC3;
593 
594 		st->conf |= AD7192_CONF_CHOP;
595 		break;
596 	case 1:
597 		st->f_order = AD7192_SYNC3_FILTER;
598 		st->mode |= AD7192_MODE_SINC3;
599 
600 		st->conf |= AD7192_CONF_CHOP;
601 		break;
602 	case 2:
603 		st->f_order = AD7192_NO_SYNC_FILTER;
604 		st->mode &= ~AD7192_MODE_SINC3;
605 
606 		st->conf &= ~AD7192_CONF_CHOP;
607 		break;
608 	case 3:
609 		st->f_order = AD7192_NO_SYNC_FILTER;
610 		st->mode |= AD7192_MODE_SINC3;
611 
612 		st->conf &= ~AD7192_CONF_CHOP;
613 		break;
614 	}
615 
616 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
617 	if (ret < 0)
618 		return ret;
619 
620 	return ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
621 }
622 
623 static int ad7192_get_3db_filter_freq(struct ad7192_state *st)
624 {
625 	unsigned int fadc;
626 
627 	fadc = DIV_ROUND_CLOSEST(st->fclk,
628 				 st->f_order * AD7192_MODE_RATE(st->mode));
629 
630 	if (st->conf & AD7192_CONF_CHOP)
631 		return DIV_ROUND_CLOSEST(fadc * 240, 1024);
632 	if (st->mode & AD7192_MODE_SINC3)
633 		return DIV_ROUND_CLOSEST(fadc * 272, 1024);
634 	else
635 		return DIV_ROUND_CLOSEST(fadc * 230, 1024);
636 }
637 
638 static int ad7192_read_raw(struct iio_dev *indio_dev,
639 			   struct iio_chan_spec const *chan,
640 			   int *val,
641 			   int *val2,
642 			   long m)
643 {
644 	struct ad7192_state *st = iio_priv(indio_dev);
645 	bool unipolar = !!(st->conf & AD7192_CONF_UNIPOLAR);
646 
647 	switch (m) {
648 	case IIO_CHAN_INFO_RAW:
649 		return ad_sigma_delta_single_conversion(indio_dev, chan, val);
650 	case IIO_CHAN_INFO_SCALE:
651 		switch (chan->type) {
652 		case IIO_VOLTAGE:
653 			mutex_lock(&st->lock);
654 			*val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
655 			*val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
656 			mutex_unlock(&st->lock);
657 			return IIO_VAL_INT_PLUS_NANO;
658 		case IIO_TEMP:
659 			*val = 0;
660 			*val2 = 1000000000 / ad7192_get_temp_scale(unipolar);
661 			return IIO_VAL_INT_PLUS_NANO;
662 		default:
663 			return -EINVAL;
664 		}
665 	case IIO_CHAN_INFO_OFFSET:
666 		if (!unipolar)
667 			*val = -(1 << (chan->scan_type.realbits - 1));
668 		else
669 			*val = 0;
670 		/* Kelvin to Celsius */
671 		if (chan->type == IIO_TEMP)
672 			*val -= 273 * ad7192_get_temp_scale(unipolar);
673 		return IIO_VAL_INT;
674 	case IIO_CHAN_INFO_SAMP_FREQ:
675 		*val = st->fclk /
676 			(st->f_order * 1024 * AD7192_MODE_RATE(st->mode));
677 		return IIO_VAL_INT;
678 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
679 		*val = ad7192_get_3db_filter_freq(st);
680 		*val2 = 1000;
681 		return IIO_VAL_FRACTIONAL;
682 	}
683 
684 	return -EINVAL;
685 }
686 
687 static int ad7192_write_raw(struct iio_dev *indio_dev,
688 			    struct iio_chan_spec const *chan,
689 			    int val,
690 			    int val2,
691 			    long mask)
692 {
693 	struct ad7192_state *st = iio_priv(indio_dev);
694 	int ret, i, div;
695 	unsigned int tmp;
696 
697 	ret = iio_device_claim_direct_mode(indio_dev);
698 	if (ret)
699 		return ret;
700 
701 	switch (mask) {
702 	case IIO_CHAN_INFO_SCALE:
703 		ret = -EINVAL;
704 		mutex_lock(&st->lock);
705 		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
706 			if (val2 == st->scale_avail[i][1]) {
707 				ret = 0;
708 				tmp = st->conf;
709 				st->conf &= ~AD7192_CONF_GAIN(-1);
710 				st->conf |= AD7192_CONF_GAIN(i);
711 				if (tmp == st->conf)
712 					break;
713 				ad_sd_write_reg(&st->sd, AD7192_REG_CONF,
714 						3, st->conf);
715 				ad7192_calibrate_all(st);
716 				break;
717 			}
718 		mutex_unlock(&st->lock);
719 		break;
720 	case IIO_CHAN_INFO_SAMP_FREQ:
721 		if (!val) {
722 			ret = -EINVAL;
723 			break;
724 		}
725 
726 		div = st->fclk / (val * st->f_order * 1024);
727 		if (div < 1 || div > 1023) {
728 			ret = -EINVAL;
729 			break;
730 		}
731 
732 		st->mode &= ~AD7192_MODE_RATE(-1);
733 		st->mode |= AD7192_MODE_RATE(div);
734 		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
735 		break;
736 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
737 		ret = ad7192_set_3db_filter_freq(st, val, val2 / 1000);
738 		break;
739 	default:
740 		ret = -EINVAL;
741 	}
742 
743 	iio_device_release_direct_mode(indio_dev);
744 
745 	return ret;
746 }
747 
748 static int ad7192_write_raw_get_fmt(struct iio_dev *indio_dev,
749 				    struct iio_chan_spec const *chan,
750 				    long mask)
751 {
752 	switch (mask) {
753 	case IIO_CHAN_INFO_SCALE:
754 		return IIO_VAL_INT_PLUS_NANO;
755 	case IIO_CHAN_INFO_SAMP_FREQ:
756 		return IIO_VAL_INT;
757 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
758 		return IIO_VAL_INT_PLUS_MICRO;
759 	default:
760 		return -EINVAL;
761 	}
762 }
763 
764 static int ad7192_read_avail(struct iio_dev *indio_dev,
765 			     struct iio_chan_spec const *chan,
766 			     const int **vals, int *type, int *length,
767 			     long mask)
768 {
769 	struct ad7192_state *st = iio_priv(indio_dev);
770 
771 	switch (mask) {
772 	case IIO_CHAN_INFO_SCALE:
773 		*vals = (int *)st->scale_avail;
774 		*type = IIO_VAL_INT_PLUS_NANO;
775 		/* Values are stored in a 2D matrix  */
776 		*length = ARRAY_SIZE(st->scale_avail) * 2;
777 
778 		return IIO_AVAIL_LIST;
779 	}
780 
781 	return -EINVAL;
782 }
783 
784 static const struct iio_info ad7192_info = {
785 	.read_raw = ad7192_read_raw,
786 	.write_raw = ad7192_write_raw,
787 	.write_raw_get_fmt = ad7192_write_raw_get_fmt,
788 	.read_avail = ad7192_read_avail,
789 	.attrs = &ad7192_attribute_group,
790 	.validate_trigger = ad_sd_validate_trigger,
791 };
792 
793 static const struct iio_info ad7195_info = {
794 	.read_raw = ad7192_read_raw,
795 	.write_raw = ad7192_write_raw,
796 	.write_raw_get_fmt = ad7192_write_raw_get_fmt,
797 	.read_avail = ad7192_read_avail,
798 	.attrs = &ad7195_attribute_group,
799 	.validate_trigger = ad_sd_validate_trigger,
800 };
801 
802 #define __AD719x_CHANNEL(_si, _channel1, _channel2, _address, _extend_name, \
803 	_type, _mask_type_av, _ext_info) \
804 	{ \
805 		.type = (_type), \
806 		.differential = ((_channel2) == -1 ? 0 : 1), \
807 		.indexed = 1, \
808 		.channel = (_channel1), \
809 		.channel2 = (_channel2), \
810 		.address = (_address), \
811 		.extend_name = (_extend_name), \
812 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
813 			BIT(IIO_CHAN_INFO_OFFSET), \
814 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
815 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
816 			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
817 		.info_mask_shared_by_type_available = (_mask_type_av), \
818 		.ext_info = (_ext_info), \
819 		.scan_index = (_si), \
820 		.scan_type = { \
821 			.sign = 'u', \
822 			.realbits = 24, \
823 			.storagebits = 32, \
824 			.endianness = IIO_BE, \
825 		}, \
826 	}
827 
828 #define AD719x_DIFF_CHANNEL(_si, _channel1, _channel2, _address) \
829 	__AD719x_CHANNEL(_si, _channel1, _channel2, _address, NULL, \
830 		IIO_VOLTAGE, BIT(IIO_CHAN_INFO_SCALE), \
831 		ad7192_calibsys_ext_info)
832 
833 #define AD719x_CHANNEL(_si, _channel1, _address) \
834 	__AD719x_CHANNEL(_si, _channel1, -1, _address, NULL, IIO_VOLTAGE, \
835 		BIT(IIO_CHAN_INFO_SCALE), ad7192_calibsys_ext_info)
836 
837 #define AD719x_SHORTED_CHANNEL(_si, _channel1, _address) \
838 	__AD719x_CHANNEL(_si, _channel1, -1, _address, "shorted", IIO_VOLTAGE, \
839 		BIT(IIO_CHAN_INFO_SCALE), ad7192_calibsys_ext_info)
840 
841 #define AD719x_TEMP_CHANNEL(_si, _address) \
842 	__AD719x_CHANNEL(_si, 0, -1, _address, NULL, IIO_TEMP, 0, NULL)
843 
844 static const struct iio_chan_spec ad7192_channels[] = {
845 	AD719x_DIFF_CHANNEL(0, 1, 2, AD7192_CH_AIN1P_AIN2M),
846 	AD719x_DIFF_CHANNEL(1, 3, 4, AD7192_CH_AIN3P_AIN4M),
847 	AD719x_TEMP_CHANNEL(2, AD7192_CH_TEMP),
848 	AD719x_SHORTED_CHANNEL(3, 2, AD7192_CH_AIN2P_AIN2M),
849 	AD719x_CHANNEL(4, 1, AD7192_CH_AIN1),
850 	AD719x_CHANNEL(5, 2, AD7192_CH_AIN2),
851 	AD719x_CHANNEL(6, 3, AD7192_CH_AIN3),
852 	AD719x_CHANNEL(7, 4, AD7192_CH_AIN4),
853 	IIO_CHAN_SOFT_TIMESTAMP(8),
854 };
855 
856 static const struct iio_chan_spec ad7193_channels[] = {
857 	AD719x_DIFF_CHANNEL(0, 1, 2, AD7193_CH_AIN1P_AIN2M),
858 	AD719x_DIFF_CHANNEL(1, 3, 4, AD7193_CH_AIN3P_AIN4M),
859 	AD719x_DIFF_CHANNEL(2, 5, 6, AD7193_CH_AIN5P_AIN6M),
860 	AD719x_DIFF_CHANNEL(3, 7, 8, AD7193_CH_AIN7P_AIN8M),
861 	AD719x_TEMP_CHANNEL(4, AD7193_CH_TEMP),
862 	AD719x_SHORTED_CHANNEL(5, 2, AD7193_CH_AIN2P_AIN2M),
863 	AD719x_CHANNEL(6, 1, AD7193_CH_AIN1),
864 	AD719x_CHANNEL(7, 2, AD7193_CH_AIN2),
865 	AD719x_CHANNEL(8, 3, AD7193_CH_AIN3),
866 	AD719x_CHANNEL(9, 4, AD7193_CH_AIN4),
867 	AD719x_CHANNEL(10, 5, AD7193_CH_AIN5),
868 	AD719x_CHANNEL(11, 6, AD7193_CH_AIN6),
869 	AD719x_CHANNEL(12, 7, AD7193_CH_AIN7),
870 	AD719x_CHANNEL(13, 8, AD7193_CH_AIN8),
871 	IIO_CHAN_SOFT_TIMESTAMP(14),
872 };
873 
874 static const struct ad7192_chip_info ad7192_chip_info_tbl[] = {
875 	[ID_AD7190] = {
876 		.chip_id = CHIPID_AD7190,
877 		.name = "ad7190",
878 	},
879 	[ID_AD7192] = {
880 		.chip_id = CHIPID_AD7192,
881 		.name = "ad7192",
882 	},
883 	[ID_AD7193] = {
884 		.chip_id = CHIPID_AD7193,
885 		.name = "ad7193",
886 	},
887 	[ID_AD7195] = {
888 		.chip_id = CHIPID_AD7195,
889 		.name = "ad7195",
890 	},
891 };
892 
893 static int ad7192_channels_config(struct iio_dev *indio_dev)
894 {
895 	struct ad7192_state *st = iio_priv(indio_dev);
896 
897 	switch (st->chip_info->chip_id) {
898 	case CHIPID_AD7193:
899 		indio_dev->channels = ad7193_channels;
900 		indio_dev->num_channels = ARRAY_SIZE(ad7193_channels);
901 		break;
902 	default:
903 		indio_dev->channels = ad7192_channels;
904 		indio_dev->num_channels = ARRAY_SIZE(ad7192_channels);
905 		break;
906 	}
907 
908 	return 0;
909 }
910 
911 static const struct of_device_id ad7192_of_match[] = {
912 	{ .compatible = "adi,ad7190", .data = &ad7192_chip_info_tbl[ID_AD7190] },
913 	{ .compatible = "adi,ad7192", .data = &ad7192_chip_info_tbl[ID_AD7192] },
914 	{ .compatible = "adi,ad7193", .data = &ad7192_chip_info_tbl[ID_AD7193] },
915 	{ .compatible = "adi,ad7195", .data = &ad7192_chip_info_tbl[ID_AD7195] },
916 	{}
917 };
918 MODULE_DEVICE_TABLE(of, ad7192_of_match);
919 
920 static int ad7192_probe(struct spi_device *spi)
921 {
922 	struct ad7192_state *st;
923 	struct iio_dev *indio_dev;
924 	int ret, voltage_uv = 0;
925 
926 	if (!spi->irq) {
927 		dev_err(&spi->dev, "no IRQ?\n");
928 		return -ENODEV;
929 	}
930 
931 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
932 	if (!indio_dev)
933 		return -ENOMEM;
934 
935 	st = iio_priv(indio_dev);
936 
937 	mutex_init(&st->lock);
938 
939 	st->avdd = devm_regulator_get(&spi->dev, "avdd");
940 	if (IS_ERR(st->avdd))
941 		return PTR_ERR(st->avdd);
942 
943 	ret = regulator_enable(st->avdd);
944 	if (ret) {
945 		dev_err(&spi->dev, "Failed to enable specified AVdd supply\n");
946 		return ret;
947 	}
948 
949 	st->dvdd = devm_regulator_get(&spi->dev, "dvdd");
950 	if (IS_ERR(st->dvdd)) {
951 		ret = PTR_ERR(st->dvdd);
952 		goto error_disable_avdd;
953 	}
954 
955 	ret = regulator_enable(st->dvdd);
956 	if (ret) {
957 		dev_err(&spi->dev, "Failed to enable specified DVdd supply\n");
958 		goto error_disable_avdd;
959 	}
960 
961 	voltage_uv = regulator_get_voltage(st->avdd);
962 
963 	if (voltage_uv > 0) {
964 		st->int_vref_mv = voltage_uv / 1000;
965 	} else {
966 		ret = voltage_uv;
967 		dev_err(&spi->dev, "Device tree error, reference voltage undefined\n");
968 		goto error_disable_avdd;
969 	}
970 
971 	spi_set_drvdata(spi, indio_dev);
972 	st->chip_info = of_device_get_match_data(&spi->dev);
973 	indio_dev->dev.parent = &spi->dev;
974 	indio_dev->name = st->chip_info->name;
975 	indio_dev->modes = INDIO_DIRECT_MODE;
976 
977 	ret = ad7192_channels_config(indio_dev);
978 	if (ret < 0)
979 		goto error_disable_dvdd;
980 
981 	if (st->chip_info->chip_id == CHIPID_AD7195)
982 		indio_dev->info = &ad7195_info;
983 	else
984 		indio_dev->info = &ad7192_info;
985 
986 	ad_sd_init(&st->sd, indio_dev, spi, &ad7192_sigma_delta_info);
987 
988 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
989 	if (ret)
990 		goto error_disable_dvdd;
991 
992 	st->fclk = AD7192_INT_FREQ_MHZ;
993 
994 	st->mclk = devm_clk_get(&st->sd.spi->dev, "mclk");
995 	if (IS_ERR(st->mclk) && PTR_ERR(st->mclk) != -ENOENT) {
996 		ret = PTR_ERR(st->mclk);
997 		goto error_remove_trigger;
998 	}
999 
1000 	st->clock_sel = ad7192_of_clock_select(st);
1001 
1002 	if (st->clock_sel == AD7192_CLK_EXT_MCLK1_2 ||
1003 	    st->clock_sel == AD7192_CLK_EXT_MCLK2) {
1004 		ret = clk_prepare_enable(st->mclk);
1005 		if (ret < 0)
1006 			goto error_remove_trigger;
1007 
1008 		st->fclk = clk_get_rate(st->mclk);
1009 		if (!ad7192_valid_external_frequency(st->fclk)) {
1010 			ret = -EINVAL;
1011 			dev_err(&spi->dev,
1012 				"External clock frequency out of bounds\n");
1013 			goto error_disable_clk;
1014 		}
1015 	}
1016 
1017 	ret = ad7192_setup(st, spi->dev.of_node);
1018 	if (ret)
1019 		goto error_disable_clk;
1020 
1021 	ret = iio_device_register(indio_dev);
1022 	if (ret < 0)
1023 		goto error_disable_clk;
1024 	return 0;
1025 
1026 error_disable_clk:
1027 	clk_disable_unprepare(st->mclk);
1028 error_remove_trigger:
1029 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
1030 error_disable_dvdd:
1031 	regulator_disable(st->dvdd);
1032 error_disable_avdd:
1033 	regulator_disable(st->avdd);
1034 
1035 	return ret;
1036 }
1037 
1038 static int ad7192_remove(struct spi_device *spi)
1039 {
1040 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
1041 	struct ad7192_state *st = iio_priv(indio_dev);
1042 
1043 	iio_device_unregister(indio_dev);
1044 	clk_disable_unprepare(st->mclk);
1045 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
1046 
1047 	regulator_disable(st->dvdd);
1048 	regulator_disable(st->avdd);
1049 
1050 	return 0;
1051 }
1052 
1053 static struct spi_driver ad7192_driver = {
1054 	.driver = {
1055 		.name	= "ad7192",
1056 		.of_match_table = ad7192_of_match,
1057 	},
1058 	.probe		= ad7192_probe,
1059 	.remove		= ad7192_remove,
1060 };
1061 module_spi_driver(ad7192_driver);
1062 
1063 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
1064 MODULE_DESCRIPTION("Analog Devices AD7190, AD7192, AD7193, AD7195 ADC");
1065 MODULE_LICENSE("GPL v2");
1066