xref: /openbmc/linux/drivers/iio/adc/ad7192.c (revision 63705da3)
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 	.irq_flags = IRQF_TRIGGER_FALLING,
297 };
298 
299 static const struct ad_sd_calib_data ad7192_calib_arr[8] = {
300 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN1},
301 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN1},
302 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN2},
303 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN2},
304 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN3},
305 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN3},
306 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN4},
307 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN4}
308 };
309 
310 static int ad7192_calibrate_all(struct ad7192_state *st)
311 {
312 	return ad_sd_calibrate_all(&st->sd, ad7192_calib_arr,
313 				   ARRAY_SIZE(ad7192_calib_arr));
314 }
315 
316 static inline bool ad7192_valid_external_frequency(u32 freq)
317 {
318 	return (freq >= AD7192_EXT_FREQ_MHZ_MIN &&
319 		freq <= AD7192_EXT_FREQ_MHZ_MAX);
320 }
321 
322 static int ad7192_of_clock_select(struct ad7192_state *st)
323 {
324 	struct device_node *np = st->sd.spi->dev.of_node;
325 	unsigned int clock_sel;
326 
327 	clock_sel = AD7192_CLK_INT;
328 
329 	/* use internal clock */
330 	if (st->mclk) {
331 		if (of_property_read_bool(np, "adi,int-clock-output-enable"))
332 			clock_sel = AD7192_CLK_INT_CO;
333 	} else {
334 		if (of_property_read_bool(np, "adi,clock-xtal"))
335 			clock_sel = AD7192_CLK_EXT_MCLK1_2;
336 		else
337 			clock_sel = AD7192_CLK_EXT_MCLK2;
338 	}
339 
340 	return clock_sel;
341 }
342 
343 static int ad7192_setup(struct ad7192_state *st, struct device_node *np)
344 {
345 	struct iio_dev *indio_dev = spi_get_drvdata(st->sd.spi);
346 	bool rej60_en, refin2_en;
347 	bool buf_en, bipolar, burnout_curr_en;
348 	unsigned long long scale_uv;
349 	int i, ret, id;
350 
351 	/* reset the serial interface */
352 	ret = ad_sd_reset(&st->sd, 48);
353 	if (ret < 0)
354 		return ret;
355 	usleep_range(500, 1000); /* Wait for at least 500us */
356 
357 	/* write/read test for device presence */
358 	ret = ad_sd_read_reg(&st->sd, AD7192_REG_ID, 1, &id);
359 	if (ret)
360 		return ret;
361 
362 	id &= AD7192_ID_MASK;
363 
364 	if (id != st->chip_info->chip_id)
365 		dev_warn(&st->sd.spi->dev, "device ID query failed (0x%X)\n",
366 			 id);
367 
368 	st->mode = AD7192_MODE_SEL(AD7192_MODE_IDLE) |
369 		AD7192_MODE_CLKSRC(st->clock_sel) |
370 		AD7192_MODE_RATE(480);
371 
372 	st->conf = AD7192_CONF_GAIN(0);
373 
374 	rej60_en = of_property_read_bool(np, "adi,rejection-60-Hz-enable");
375 	if (rej60_en)
376 		st->mode |= AD7192_MODE_REJ60;
377 
378 	refin2_en = of_property_read_bool(np, "adi,refin2-pins-enable");
379 	if (refin2_en && st->chip_info->chip_id != CHIPID_AD7195)
380 		st->conf |= AD7192_CONF_REFSEL;
381 
382 	st->conf &= ~AD7192_CONF_CHOP;
383 	st->f_order = AD7192_NO_SYNC_FILTER;
384 
385 	buf_en = of_property_read_bool(np, "adi,buffer-enable");
386 	if (buf_en)
387 		st->conf |= AD7192_CONF_BUF;
388 
389 	bipolar = of_property_read_bool(np, "bipolar");
390 	if (!bipolar)
391 		st->conf |= AD7192_CONF_UNIPOLAR;
392 
393 	burnout_curr_en = of_property_read_bool(np,
394 						"adi,burnout-currents-enable");
395 	if (burnout_curr_en && buf_en) {
396 		st->conf |= AD7192_CONF_BURN;
397 	} else if (burnout_curr_en) {
398 		dev_warn(&st->sd.spi->dev,
399 			 "Can't enable burnout currents: see CHOP or buffer\n");
400 	}
401 
402 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
403 	if (ret)
404 		return ret;
405 
406 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
407 	if (ret)
408 		return ret;
409 
410 	ret = ad7192_calibrate_all(st);
411 	if (ret)
412 		return ret;
413 
414 	/* Populate available ADC input ranges */
415 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
416 		scale_uv = ((u64)st->int_vref_mv * 100000000)
417 			>> (indio_dev->channels[0].scan_type.realbits -
418 			((st->conf & AD7192_CONF_UNIPOLAR) ? 0 : 1));
419 		scale_uv >>= i;
420 
421 		st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
422 		st->scale_avail[i][0] = scale_uv;
423 	}
424 
425 	return 0;
426 }
427 
428 static ssize_t ad7192_show_ac_excitation(struct device *dev,
429 					 struct device_attribute *attr,
430 					 char *buf)
431 {
432 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
433 	struct ad7192_state *st = iio_priv(indio_dev);
434 
435 	return sprintf(buf, "%d\n", !!(st->mode & AD7192_MODE_ACX));
436 }
437 
438 static ssize_t ad7192_show_bridge_switch(struct device *dev,
439 					 struct device_attribute *attr,
440 					 char *buf)
441 {
442 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
443 	struct ad7192_state *st = iio_priv(indio_dev);
444 
445 	return sprintf(buf, "%d\n", !!(st->gpocon & AD7192_GPOCON_BPDSW));
446 }
447 
448 static ssize_t ad7192_set(struct device *dev,
449 			  struct device_attribute *attr,
450 			  const char *buf,
451 			  size_t len)
452 {
453 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
454 	struct ad7192_state *st = iio_priv(indio_dev);
455 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
456 	int ret;
457 	bool val;
458 
459 	ret = strtobool(buf, &val);
460 	if (ret < 0)
461 		return ret;
462 
463 	ret = iio_device_claim_direct_mode(indio_dev);
464 	if (ret)
465 		return ret;
466 
467 	switch ((u32)this_attr->address) {
468 	case AD7192_REG_GPOCON:
469 		if (val)
470 			st->gpocon |= AD7192_GPOCON_BPDSW;
471 		else
472 			st->gpocon &= ~AD7192_GPOCON_BPDSW;
473 
474 		ad_sd_write_reg(&st->sd, AD7192_REG_GPOCON, 1, st->gpocon);
475 		break;
476 	case AD7192_REG_MODE:
477 		if (val)
478 			st->mode |= AD7192_MODE_ACX;
479 		else
480 			st->mode &= ~AD7192_MODE_ACX;
481 
482 		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
483 		break;
484 	default:
485 		ret = -EINVAL;
486 	}
487 
488 	iio_device_release_direct_mode(indio_dev);
489 
490 	return ret ? ret : len;
491 }
492 
493 static void ad7192_get_available_filter_freq(struct ad7192_state *st,
494 						    int *freq)
495 {
496 	unsigned int fadc;
497 
498 	/* Formulas for filter at page 25 of the datasheet */
499 	fadc = DIV_ROUND_CLOSEST(st->fclk,
500 				 AD7192_SYNC4_FILTER * AD7192_MODE_RATE(st->mode));
501 	freq[0] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
502 
503 	fadc = DIV_ROUND_CLOSEST(st->fclk,
504 				 AD7192_SYNC3_FILTER * AD7192_MODE_RATE(st->mode));
505 	freq[1] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
506 
507 	fadc = DIV_ROUND_CLOSEST(st->fclk, AD7192_MODE_RATE(st->mode));
508 	freq[2] = DIV_ROUND_CLOSEST(fadc * 230, 1024);
509 	freq[3] = DIV_ROUND_CLOSEST(fadc * 272, 1024);
510 }
511 
512 static ssize_t ad7192_show_filter_avail(struct device *dev,
513 					struct device_attribute *attr,
514 					char *buf)
515 {
516 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
517 	struct ad7192_state *st = iio_priv(indio_dev);
518 	unsigned int freq_avail[4], i;
519 	size_t len = 0;
520 
521 	ad7192_get_available_filter_freq(st, freq_avail);
522 
523 	for (i = 0; i < ARRAY_SIZE(freq_avail); i++)
524 		len += scnprintf(buf + len, PAGE_SIZE - len,
525 				 "%d.%d ", freq_avail[i] / 1000,
526 				 freq_avail[i] % 1000);
527 
528 	buf[len - 1] = '\n';
529 
530 	return len;
531 }
532 
533 static IIO_DEVICE_ATTR(filter_low_pass_3db_frequency_available,
534 		       0444, ad7192_show_filter_avail, NULL, 0);
535 
536 static IIO_DEVICE_ATTR(bridge_switch_en, 0644,
537 		       ad7192_show_bridge_switch, ad7192_set,
538 		       AD7192_REG_GPOCON);
539 
540 static IIO_DEVICE_ATTR(ac_excitation_en, 0644,
541 		       ad7192_show_ac_excitation, ad7192_set,
542 		       AD7192_REG_MODE);
543 
544 static struct attribute *ad7192_attributes[] = {
545 	&iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
546 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
547 	&iio_dev_attr_ac_excitation_en.dev_attr.attr,
548 	NULL
549 };
550 
551 static const struct attribute_group ad7192_attribute_group = {
552 	.attrs = ad7192_attributes,
553 };
554 
555 static struct attribute *ad7195_attributes[] = {
556 	&iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
557 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
558 	NULL
559 };
560 
561 static const struct attribute_group ad7195_attribute_group = {
562 	.attrs = ad7195_attributes,
563 };
564 
565 static unsigned int ad7192_get_temp_scale(bool unipolar)
566 {
567 	return unipolar ? 2815 * 2 : 2815;
568 }
569 
570 static int ad7192_set_3db_filter_freq(struct ad7192_state *st,
571 				      int val, int val2)
572 {
573 	int freq_avail[4], i, ret, freq;
574 	unsigned int diff_new, diff_old;
575 	int idx = 0;
576 
577 	diff_old = U32_MAX;
578 	freq = val * 1000 + val2;
579 
580 	ad7192_get_available_filter_freq(st, freq_avail);
581 
582 	for (i = 0; i < ARRAY_SIZE(freq_avail); i++) {
583 		diff_new = abs(freq - freq_avail[i]);
584 		if (diff_new < diff_old) {
585 			diff_old = diff_new;
586 			idx = i;
587 		}
588 	}
589 
590 	switch (idx) {
591 	case 0:
592 		st->f_order = AD7192_SYNC4_FILTER;
593 		st->mode &= ~AD7192_MODE_SINC3;
594 
595 		st->conf |= AD7192_CONF_CHOP;
596 		break;
597 	case 1:
598 		st->f_order = AD7192_SYNC3_FILTER;
599 		st->mode |= AD7192_MODE_SINC3;
600 
601 		st->conf |= AD7192_CONF_CHOP;
602 		break;
603 	case 2:
604 		st->f_order = AD7192_NO_SYNC_FILTER;
605 		st->mode &= ~AD7192_MODE_SINC3;
606 
607 		st->conf &= ~AD7192_CONF_CHOP;
608 		break;
609 	case 3:
610 		st->f_order = AD7192_NO_SYNC_FILTER;
611 		st->mode |= AD7192_MODE_SINC3;
612 
613 		st->conf &= ~AD7192_CONF_CHOP;
614 		break;
615 	}
616 
617 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
618 	if (ret < 0)
619 		return ret;
620 
621 	return ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
622 }
623 
624 static int ad7192_get_3db_filter_freq(struct ad7192_state *st)
625 {
626 	unsigned int fadc;
627 
628 	fadc = DIV_ROUND_CLOSEST(st->fclk,
629 				 st->f_order * AD7192_MODE_RATE(st->mode));
630 
631 	if (st->conf & AD7192_CONF_CHOP)
632 		return DIV_ROUND_CLOSEST(fadc * 240, 1024);
633 	if (st->mode & AD7192_MODE_SINC3)
634 		return DIV_ROUND_CLOSEST(fadc * 272, 1024);
635 	else
636 		return DIV_ROUND_CLOSEST(fadc * 230, 1024);
637 }
638 
639 static int ad7192_read_raw(struct iio_dev *indio_dev,
640 			   struct iio_chan_spec const *chan,
641 			   int *val,
642 			   int *val2,
643 			   long m)
644 {
645 	struct ad7192_state *st = iio_priv(indio_dev);
646 	bool unipolar = !!(st->conf & AD7192_CONF_UNIPOLAR);
647 
648 	switch (m) {
649 	case IIO_CHAN_INFO_RAW:
650 		return ad_sigma_delta_single_conversion(indio_dev, chan, val);
651 	case IIO_CHAN_INFO_SCALE:
652 		switch (chan->type) {
653 		case IIO_VOLTAGE:
654 			mutex_lock(&st->lock);
655 			*val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
656 			*val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
657 			mutex_unlock(&st->lock);
658 			return IIO_VAL_INT_PLUS_NANO;
659 		case IIO_TEMP:
660 			*val = 0;
661 			*val2 = 1000000000 / ad7192_get_temp_scale(unipolar);
662 			return IIO_VAL_INT_PLUS_NANO;
663 		default:
664 			return -EINVAL;
665 		}
666 	case IIO_CHAN_INFO_OFFSET:
667 		if (!unipolar)
668 			*val = -(1 << (chan->scan_type.realbits - 1));
669 		else
670 			*val = 0;
671 		/* Kelvin to Celsius */
672 		if (chan->type == IIO_TEMP)
673 			*val -= 273 * ad7192_get_temp_scale(unipolar);
674 		return IIO_VAL_INT;
675 	case IIO_CHAN_INFO_SAMP_FREQ:
676 		*val = st->fclk /
677 			(st->f_order * 1024 * AD7192_MODE_RATE(st->mode));
678 		return IIO_VAL_INT;
679 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
680 		*val = ad7192_get_3db_filter_freq(st);
681 		*val2 = 1000;
682 		return IIO_VAL_FRACTIONAL;
683 	}
684 
685 	return -EINVAL;
686 }
687 
688 static int ad7192_write_raw(struct iio_dev *indio_dev,
689 			    struct iio_chan_spec const *chan,
690 			    int val,
691 			    int val2,
692 			    long mask)
693 {
694 	struct ad7192_state *st = iio_priv(indio_dev);
695 	int ret, i, div;
696 	unsigned int tmp;
697 
698 	ret = iio_device_claim_direct_mode(indio_dev);
699 	if (ret)
700 		return ret;
701 
702 	switch (mask) {
703 	case IIO_CHAN_INFO_SCALE:
704 		ret = -EINVAL;
705 		mutex_lock(&st->lock);
706 		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
707 			if (val2 == st->scale_avail[i][1]) {
708 				ret = 0;
709 				tmp = st->conf;
710 				st->conf &= ~AD7192_CONF_GAIN(-1);
711 				st->conf |= AD7192_CONF_GAIN(i);
712 				if (tmp == st->conf)
713 					break;
714 				ad_sd_write_reg(&st->sd, AD7192_REG_CONF,
715 						3, st->conf);
716 				ad7192_calibrate_all(st);
717 				break;
718 			}
719 		mutex_unlock(&st->lock);
720 		break;
721 	case IIO_CHAN_INFO_SAMP_FREQ:
722 		if (!val) {
723 			ret = -EINVAL;
724 			break;
725 		}
726 
727 		div = st->fclk / (val * st->f_order * 1024);
728 		if (div < 1 || div > 1023) {
729 			ret = -EINVAL;
730 			break;
731 		}
732 
733 		st->mode &= ~AD7192_MODE_RATE(-1);
734 		st->mode |= AD7192_MODE_RATE(div);
735 		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
736 		break;
737 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
738 		ret = ad7192_set_3db_filter_freq(st, val, val2 / 1000);
739 		break;
740 	default:
741 		ret = -EINVAL;
742 	}
743 
744 	iio_device_release_direct_mode(indio_dev);
745 
746 	return ret;
747 }
748 
749 static int ad7192_write_raw_get_fmt(struct iio_dev *indio_dev,
750 				    struct iio_chan_spec const *chan,
751 				    long mask)
752 {
753 	switch (mask) {
754 	case IIO_CHAN_INFO_SCALE:
755 		return IIO_VAL_INT_PLUS_NANO;
756 	case IIO_CHAN_INFO_SAMP_FREQ:
757 		return IIO_VAL_INT;
758 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
759 		return IIO_VAL_INT_PLUS_MICRO;
760 	default:
761 		return -EINVAL;
762 	}
763 }
764 
765 static int ad7192_read_avail(struct iio_dev *indio_dev,
766 			     struct iio_chan_spec const *chan,
767 			     const int **vals, int *type, int *length,
768 			     long mask)
769 {
770 	struct ad7192_state *st = iio_priv(indio_dev);
771 
772 	switch (mask) {
773 	case IIO_CHAN_INFO_SCALE:
774 		*vals = (int *)st->scale_avail;
775 		*type = IIO_VAL_INT_PLUS_NANO;
776 		/* Values are stored in a 2D matrix  */
777 		*length = ARRAY_SIZE(st->scale_avail) * 2;
778 
779 		return IIO_AVAIL_LIST;
780 	}
781 
782 	return -EINVAL;
783 }
784 
785 static const struct iio_info ad7192_info = {
786 	.read_raw = ad7192_read_raw,
787 	.write_raw = ad7192_write_raw,
788 	.write_raw_get_fmt = ad7192_write_raw_get_fmt,
789 	.read_avail = ad7192_read_avail,
790 	.attrs = &ad7192_attribute_group,
791 	.validate_trigger = ad_sd_validate_trigger,
792 };
793 
794 static const struct iio_info ad7195_info = {
795 	.read_raw = ad7192_read_raw,
796 	.write_raw = ad7192_write_raw,
797 	.write_raw_get_fmt = ad7192_write_raw_get_fmt,
798 	.read_avail = ad7192_read_avail,
799 	.attrs = &ad7195_attribute_group,
800 	.validate_trigger = ad_sd_validate_trigger,
801 };
802 
803 #define __AD719x_CHANNEL(_si, _channel1, _channel2, _address, _extend_name, \
804 	_type, _mask_type_av, _ext_info) \
805 	{ \
806 		.type = (_type), \
807 		.differential = ((_channel2) == -1 ? 0 : 1), \
808 		.indexed = 1, \
809 		.channel = (_channel1), \
810 		.channel2 = (_channel2), \
811 		.address = (_address), \
812 		.extend_name = (_extend_name), \
813 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
814 			BIT(IIO_CHAN_INFO_OFFSET), \
815 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
816 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
817 			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
818 		.info_mask_shared_by_type_available = (_mask_type_av), \
819 		.ext_info = (_ext_info), \
820 		.scan_index = (_si), \
821 		.scan_type = { \
822 			.sign = 'u', \
823 			.realbits = 24, \
824 			.storagebits = 32, \
825 			.endianness = IIO_BE, \
826 		}, \
827 	}
828 
829 #define AD719x_DIFF_CHANNEL(_si, _channel1, _channel2, _address) \
830 	__AD719x_CHANNEL(_si, _channel1, _channel2, _address, NULL, \
831 		IIO_VOLTAGE, BIT(IIO_CHAN_INFO_SCALE), \
832 		ad7192_calibsys_ext_info)
833 
834 #define AD719x_CHANNEL(_si, _channel1, _address) \
835 	__AD719x_CHANNEL(_si, _channel1, -1, _address, NULL, IIO_VOLTAGE, \
836 		BIT(IIO_CHAN_INFO_SCALE), ad7192_calibsys_ext_info)
837 
838 #define AD719x_SHORTED_CHANNEL(_si, _channel1, _address) \
839 	__AD719x_CHANNEL(_si, _channel1, -1, _address, "shorted", IIO_VOLTAGE, \
840 		BIT(IIO_CHAN_INFO_SCALE), ad7192_calibsys_ext_info)
841 
842 #define AD719x_TEMP_CHANNEL(_si, _address) \
843 	__AD719x_CHANNEL(_si, 0, -1, _address, NULL, IIO_TEMP, 0, NULL)
844 
845 static const struct iio_chan_spec ad7192_channels[] = {
846 	AD719x_DIFF_CHANNEL(0, 1, 2, AD7192_CH_AIN1P_AIN2M),
847 	AD719x_DIFF_CHANNEL(1, 3, 4, AD7192_CH_AIN3P_AIN4M),
848 	AD719x_TEMP_CHANNEL(2, AD7192_CH_TEMP),
849 	AD719x_SHORTED_CHANNEL(3, 2, AD7192_CH_AIN2P_AIN2M),
850 	AD719x_CHANNEL(4, 1, AD7192_CH_AIN1),
851 	AD719x_CHANNEL(5, 2, AD7192_CH_AIN2),
852 	AD719x_CHANNEL(6, 3, AD7192_CH_AIN3),
853 	AD719x_CHANNEL(7, 4, AD7192_CH_AIN4),
854 	IIO_CHAN_SOFT_TIMESTAMP(8),
855 };
856 
857 static const struct iio_chan_spec ad7193_channels[] = {
858 	AD719x_DIFF_CHANNEL(0, 1, 2, AD7193_CH_AIN1P_AIN2M),
859 	AD719x_DIFF_CHANNEL(1, 3, 4, AD7193_CH_AIN3P_AIN4M),
860 	AD719x_DIFF_CHANNEL(2, 5, 6, AD7193_CH_AIN5P_AIN6M),
861 	AD719x_DIFF_CHANNEL(3, 7, 8, AD7193_CH_AIN7P_AIN8M),
862 	AD719x_TEMP_CHANNEL(4, AD7193_CH_TEMP),
863 	AD719x_SHORTED_CHANNEL(5, 2, AD7193_CH_AIN2P_AIN2M),
864 	AD719x_CHANNEL(6, 1, AD7193_CH_AIN1),
865 	AD719x_CHANNEL(7, 2, AD7193_CH_AIN2),
866 	AD719x_CHANNEL(8, 3, AD7193_CH_AIN3),
867 	AD719x_CHANNEL(9, 4, AD7193_CH_AIN4),
868 	AD719x_CHANNEL(10, 5, AD7193_CH_AIN5),
869 	AD719x_CHANNEL(11, 6, AD7193_CH_AIN6),
870 	AD719x_CHANNEL(12, 7, AD7193_CH_AIN7),
871 	AD719x_CHANNEL(13, 8, AD7193_CH_AIN8),
872 	IIO_CHAN_SOFT_TIMESTAMP(14),
873 };
874 
875 static const struct ad7192_chip_info ad7192_chip_info_tbl[] = {
876 	[ID_AD7190] = {
877 		.chip_id = CHIPID_AD7190,
878 		.name = "ad7190",
879 	},
880 	[ID_AD7192] = {
881 		.chip_id = CHIPID_AD7192,
882 		.name = "ad7192",
883 	},
884 	[ID_AD7193] = {
885 		.chip_id = CHIPID_AD7193,
886 		.name = "ad7193",
887 	},
888 	[ID_AD7195] = {
889 		.chip_id = CHIPID_AD7195,
890 		.name = "ad7195",
891 	},
892 };
893 
894 static int ad7192_channels_config(struct iio_dev *indio_dev)
895 {
896 	struct ad7192_state *st = iio_priv(indio_dev);
897 
898 	switch (st->chip_info->chip_id) {
899 	case CHIPID_AD7193:
900 		indio_dev->channels = ad7193_channels;
901 		indio_dev->num_channels = ARRAY_SIZE(ad7193_channels);
902 		break;
903 	default:
904 		indio_dev->channels = ad7192_channels;
905 		indio_dev->num_channels = ARRAY_SIZE(ad7192_channels);
906 		break;
907 	}
908 
909 	return 0;
910 }
911 
912 static void ad7192_reg_disable(void *reg)
913 {
914 	regulator_disable(reg);
915 }
916 
917 static void ad7192_clk_disable(void *clk)
918 {
919 	clk_disable_unprepare(clk);
920 }
921 
922 static int ad7192_probe(struct spi_device *spi)
923 {
924 	struct ad7192_state *st;
925 	struct iio_dev *indio_dev;
926 	int ret;
927 
928 	if (!spi->irq) {
929 		dev_err(&spi->dev, "no IRQ?\n");
930 		return -ENODEV;
931 	}
932 
933 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
934 	if (!indio_dev)
935 		return -ENOMEM;
936 
937 	st = iio_priv(indio_dev);
938 
939 	mutex_init(&st->lock);
940 
941 	st->avdd = devm_regulator_get(&spi->dev, "avdd");
942 	if (IS_ERR(st->avdd))
943 		return PTR_ERR(st->avdd);
944 
945 	ret = regulator_enable(st->avdd);
946 	if (ret) {
947 		dev_err(&spi->dev, "Failed to enable specified AVdd supply\n");
948 		return ret;
949 	}
950 
951 	ret = devm_add_action_or_reset(&spi->dev, ad7192_reg_disable, st->avdd);
952 	if (ret)
953 		return ret;
954 
955 	st->dvdd = devm_regulator_get(&spi->dev, "dvdd");
956 	if (IS_ERR(st->dvdd))
957 		return PTR_ERR(st->dvdd);
958 
959 	ret = regulator_enable(st->dvdd);
960 	if (ret) {
961 		dev_err(&spi->dev, "Failed to enable specified DVdd supply\n");
962 		return ret;
963 	}
964 
965 	ret = devm_add_action_or_reset(&spi->dev, ad7192_reg_disable, st->dvdd);
966 	if (ret)
967 		return ret;
968 
969 	ret = regulator_get_voltage(st->avdd);
970 	if (ret < 0) {
971 		dev_err(&spi->dev, "Device tree error, reference voltage undefined\n");
972 		return ret;
973 	}
974 	st->int_vref_mv = ret / 1000;
975 
976 	st->chip_info = of_device_get_match_data(&spi->dev);
977 	indio_dev->name = st->chip_info->name;
978 	indio_dev->modes = INDIO_DIRECT_MODE;
979 
980 	ret = ad7192_channels_config(indio_dev);
981 	if (ret < 0)
982 		return ret;
983 
984 	if (st->chip_info->chip_id == CHIPID_AD7195)
985 		indio_dev->info = &ad7195_info;
986 	else
987 		indio_dev->info = &ad7192_info;
988 
989 	ad_sd_init(&st->sd, indio_dev, spi, &ad7192_sigma_delta_info);
990 
991 	ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
992 	if (ret)
993 		return ret;
994 
995 	st->fclk = AD7192_INT_FREQ_MHZ;
996 
997 	st->mclk = devm_clk_get_optional(&spi->dev, "mclk");
998 	if (IS_ERR(st->mclk))
999 		return PTR_ERR(st->mclk);
1000 
1001 	st->clock_sel = ad7192_of_clock_select(st);
1002 
1003 	if (st->clock_sel == AD7192_CLK_EXT_MCLK1_2 ||
1004 	    st->clock_sel == AD7192_CLK_EXT_MCLK2) {
1005 		ret = clk_prepare_enable(st->mclk);
1006 		if (ret < 0)
1007 			return ret;
1008 
1009 		ret = devm_add_action_or_reset(&spi->dev, ad7192_clk_disable,
1010 					       st->mclk);
1011 		if (ret)
1012 			return ret;
1013 
1014 		st->fclk = clk_get_rate(st->mclk);
1015 		if (!ad7192_valid_external_frequency(st->fclk)) {
1016 			dev_err(&spi->dev,
1017 				"External clock frequency out of bounds\n");
1018 			return -EINVAL;
1019 		}
1020 	}
1021 
1022 	ret = ad7192_setup(st, spi->dev.of_node);
1023 	if (ret)
1024 		return ret;
1025 
1026 	return devm_iio_device_register(&spi->dev, indio_dev);
1027 }
1028 
1029 static const struct of_device_id ad7192_of_match[] = {
1030 	{ .compatible = "adi,ad7190", .data = &ad7192_chip_info_tbl[ID_AD7190] },
1031 	{ .compatible = "adi,ad7192", .data = &ad7192_chip_info_tbl[ID_AD7192] },
1032 	{ .compatible = "adi,ad7193", .data = &ad7192_chip_info_tbl[ID_AD7193] },
1033 	{ .compatible = "adi,ad7195", .data = &ad7192_chip_info_tbl[ID_AD7195] },
1034 	{}
1035 };
1036 MODULE_DEVICE_TABLE(of, ad7192_of_match);
1037 
1038 static struct spi_driver ad7192_driver = {
1039 	.driver = {
1040 		.name	= "ad7192",
1041 		.of_match_table = ad7192_of_match,
1042 	},
1043 	.probe		= ad7192_probe,
1044 };
1045 module_spi_driver(ad7192_driver);
1046 
1047 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
1048 MODULE_DESCRIPTION("Analog Devices AD7190, AD7192, AD7193, AD7195 ADC");
1049 MODULE_LICENSE("GPL v2");
1050