1 /*
2  * AD7190 AD7192 AD7195 SPI ADC driver
3  *
4  * Copyright 2011-2012 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2.
7  */
8 
9 #include <linux/interrupt.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 
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/trigger.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include <linux/iio/triggered_buffer.h>
26 #include <linux/iio/adc/ad_sigma_delta.h>
27 
28 #include "ad7192.h"
29 
30 /* Registers */
31 #define AD7192_REG_COMM		0 /* Communications Register (WO, 8-bit) */
32 #define AD7192_REG_STAT		0 /* Status Register	     (RO, 8-bit) */
33 #define AD7192_REG_MODE		1 /* Mode Register	     (RW, 24-bit */
34 #define AD7192_REG_CONF		2 /* Configuration Register  (RW, 24-bit) */
35 #define AD7192_REG_DATA		3 /* Data Register	     (RO, 24/32-bit) */
36 #define AD7192_REG_ID		4 /* ID Register	     (RO, 8-bit) */
37 #define AD7192_REG_GPOCON	5 /* GPOCON Register	     (RO, 8-bit) */
38 #define AD7192_REG_OFFSET	6 /* Offset Register	     (RW, 16-bit
39 				   * (AD7792)/24-bit (AD7192)) */
40 #define AD7192_REG_FULLSALE	7 /* Full-Scale Register
41 				   * (RW, 16-bit (AD7792)/24-bit (AD7192)) */
42 
43 /* Communications Register Bit Designations (AD7192_REG_COMM) */
44 #define AD7192_COMM_WEN		BIT(7) /* Write Enable */
45 #define AD7192_COMM_WRITE	0 /* Write Operation */
46 #define AD7192_COMM_READ	BIT(6) /* Read Operation */
47 #define AD7192_COMM_ADDR(x)	(((x) & 0x7) << 3) /* Register Address */
48 #define AD7192_COMM_CREAD	BIT(2) /* Continuous Read of Data Register */
49 
50 /* Status Register Bit Designations (AD7192_REG_STAT) */
51 #define AD7192_STAT_RDY		BIT(7) /* Ready */
52 #define AD7192_STAT_ERR		BIT(6) /* Error (Overrange, Underrange) */
53 #define AD7192_STAT_NOREF	BIT(5) /* Error no external reference */
54 #define AD7192_STAT_PARITY	BIT(4) /* Parity */
55 #define AD7192_STAT_CH3		BIT(2) /* Channel 3 */
56 #define AD7192_STAT_CH2		BIT(1) /* Channel 2 */
57 #define AD7192_STAT_CH1		BIT(0) /* Channel 1 */
58 
59 /* Mode Register Bit Designations (AD7192_REG_MODE) */
60 #define AD7192_MODE_SEL(x)	(((x) & 0x7) << 21) /* Operation Mode Select */
61 #define AD7192_MODE_SEL_MASK	(0x7 << 21) /* Operation Mode Select Mask */
62 #define AD7192_MODE_DAT_STA	BIT(20) /* Status Register transmission */
63 #define AD7192_MODE_CLKSRC(x)	(((x) & 0x3) << 18) /* Clock Source Select */
64 #define AD7192_MODE_SINC3	BIT(15) /* SINC3 Filter Select */
65 #define AD7192_MODE_ACX		BIT(14) /* AC excitation enable(AD7195 only)*/
66 #define AD7192_MODE_ENPAR	BIT(13) /* Parity Enable */
67 #define AD7192_MODE_CLKDIV	BIT(12) /* Clock divide by 2 (AD7190/2 only)*/
68 #define AD7192_MODE_SCYCLE	BIT(11) /* Single cycle conversion */
69 #define AD7192_MODE_REJ60	BIT(10) /* 50/60Hz notch filter */
70 #define AD7192_MODE_RATE(x)	((x) & 0x3FF) /* Filter Update Rate Select */
71 
72 /* Mode Register: AD7192_MODE_SEL options */
73 #define AD7192_MODE_CONT		0 /* Continuous Conversion Mode */
74 #define AD7192_MODE_SINGLE		1 /* Single Conversion Mode */
75 #define AD7192_MODE_IDLE		2 /* Idle Mode */
76 #define AD7192_MODE_PWRDN		3 /* Power-Down Mode */
77 #define AD7192_MODE_CAL_INT_ZERO	4 /* Internal Zero-Scale Calibration */
78 #define AD7192_MODE_CAL_INT_FULL	5 /* Internal Full-Scale Calibration */
79 #define AD7192_MODE_CAL_SYS_ZERO	6 /* System Zero-Scale Calibration */
80 #define AD7192_MODE_CAL_SYS_FULL	7 /* System Full-Scale Calibration */
81 
82 /* Mode Register: AD7192_MODE_CLKSRC options */
83 #define AD7192_CLK_EXT_MCLK1_2		0 /* External 4.92 MHz Clock connected
84 					   * from MCLK1 to MCLK2 */
85 #define AD7192_CLK_EXT_MCLK2		1 /* External Clock applied to MCLK2 */
86 #define AD7192_CLK_INT			2 /* Internal 4.92 MHz Clock not
87 					   * available at the MCLK2 pin */
88 #define AD7192_CLK_INT_CO		3 /* Internal 4.92 MHz Clock available
89 					   * at the MCLK2 pin */
90 
91 
92 /* Configuration Register Bit Designations (AD7192_REG_CONF) */
93 
94 #define AD7192_CONF_CHOP	BIT(23) /* CHOP enable */
95 #define AD7192_CONF_REFSEL	BIT(20) /* REFIN1/REFIN2 Reference Select */
96 #define AD7192_CONF_CHAN(x)	(((1 << (x)) & 0xFF) << 8) /* Channel select */
97 #define AD7192_CONF_CHAN_MASK	(0xFF << 8) /* Channel select mask */
98 #define AD7192_CONF_BURN	BIT(7) /* Burnout current enable */
99 #define AD7192_CONF_REFDET	BIT(6) /* Reference detect enable */
100 #define AD7192_CONF_BUF		BIT(4) /* Buffered Mode Enable */
101 #define AD7192_CONF_UNIPOLAR	BIT(3) /* Unipolar/Bipolar Enable */
102 #define AD7192_CONF_GAIN(x)	((x) & 0x7) /* Gain Select */
103 
104 #define AD7192_CH_AIN1P_AIN2M	0 /* AIN1(+) - AIN2(-) */
105 #define AD7192_CH_AIN3P_AIN4M	1 /* AIN3(+) - AIN4(-) */
106 #define AD7192_CH_TEMP		2 /* Temp Sensor */
107 #define AD7192_CH_AIN2P_AIN2M	3 /* AIN2(+) - AIN2(-) */
108 #define AD7192_CH_AIN1		4 /* AIN1 - AINCOM */
109 #define AD7192_CH_AIN2		5 /* AIN2 - AINCOM */
110 #define AD7192_CH_AIN3		6 /* AIN3 - AINCOM */
111 #define AD7192_CH_AIN4		7 /* AIN4 - AINCOM */
112 
113 /* ID Register Bit Designations (AD7192_REG_ID) */
114 #define ID_AD7190		0x4
115 #define ID_AD7192		0x0
116 #define ID_AD7195		0x6
117 #define AD7192_ID_MASK		0x0F
118 
119 /* GPOCON Register Bit Designations (AD7192_REG_GPOCON) */
120 #define AD7192_GPOCON_BPDSW	BIT(6) /* Bridge power-down switch enable */
121 #define AD7192_GPOCON_GP32EN	BIT(5) /* Digital Output P3 and P2 enable */
122 #define AD7192_GPOCON_GP10EN	BIT(4) /* Digital Output P1 and P0 enable */
123 #define AD7192_GPOCON_P3DAT	BIT(3) /* P3 state */
124 #define AD7192_GPOCON_P2DAT	BIT(2) /* P2 state */
125 #define AD7192_GPOCON_P1DAT	BIT(1) /* P1 state */
126 #define AD7192_GPOCON_P0DAT	BIT(0) /* P0 state */
127 
128 #define AD7192_INT_FREQ_MHz	4915200
129 
130 /* NOTE:
131  * The AD7190/2/5 features a dual use data out ready DOUT/RDY output.
132  * In order to avoid contentions on the SPI bus, it's therefore necessary
133  * to use spi bus locking.
134  *
135  * The DOUT/RDY output must also be wired to an interrupt capable GPIO.
136  */
137 
138 struct ad7192_state {
139 	struct regulator		*reg;
140 	u16				int_vref_mv;
141 	u32				mclk;
142 	u32				f_order;
143 	u32				mode;
144 	u32				conf;
145 	u32				scale_avail[8][2];
146 	u8				gpocon;
147 	u8				devid;
148 
149 	struct ad_sigma_delta		sd;
150 };
151 
ad_sigma_delta_to_ad7192(struct ad_sigma_delta * sd)152 static struct ad7192_state *ad_sigma_delta_to_ad7192(struct ad_sigma_delta *sd)
153 {
154 	return container_of(sd, struct ad7192_state, sd);
155 }
156 
ad7192_set_channel(struct ad_sigma_delta * sd,unsigned int channel)157 static int ad7192_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
158 {
159 	struct ad7192_state *st = ad_sigma_delta_to_ad7192(sd);
160 
161 	st->conf &= ~AD7192_CONF_CHAN_MASK;
162 	st->conf |= AD7192_CONF_CHAN(channel);
163 
164 	return ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
165 }
166 
ad7192_set_mode(struct ad_sigma_delta * sd,enum ad_sigma_delta_mode mode)167 static int ad7192_set_mode(struct ad_sigma_delta *sd,
168 			   enum ad_sigma_delta_mode mode)
169 {
170 	struct ad7192_state *st = ad_sigma_delta_to_ad7192(sd);
171 
172 	st->mode &= ~AD7192_MODE_SEL_MASK;
173 	st->mode |= AD7192_MODE_SEL(mode);
174 
175 	return ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
176 }
177 
178 static const struct ad_sigma_delta_info ad7192_sigma_delta_info = {
179 	.set_channel = ad7192_set_channel,
180 	.set_mode = ad7192_set_mode,
181 	.has_registers = true,
182 	.addr_shift = 3,
183 	.read_mask = BIT(6),
184 };
185 
186 static const struct ad_sd_calib_data ad7192_calib_arr[8] = {
187 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN1},
188 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN1},
189 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN2},
190 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN2},
191 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN3},
192 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN3},
193 	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN4},
194 	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN4}
195 };
196 
ad7192_calibrate_all(struct ad7192_state * st)197 static int ad7192_calibrate_all(struct ad7192_state *st)
198 {
199 		return ad_sd_calibrate_all(&st->sd, ad7192_calib_arr,
200 				ARRAY_SIZE(ad7192_calib_arr));
201 }
202 
ad7192_setup(struct ad7192_state * st,const struct ad7192_platform_data * pdata)203 static int ad7192_setup(struct ad7192_state *st,
204 	const struct ad7192_platform_data *pdata)
205 {
206 	struct iio_dev *indio_dev = spi_get_drvdata(st->sd.spi);
207 	unsigned long long scale_uv;
208 	int i, ret, id;
209 	u8 ones[6];
210 
211 	/* reset the serial interface */
212 	memset(&ones, 0xFF, 6);
213 	ret = spi_write(st->sd.spi, &ones, 6);
214 	if (ret < 0)
215 		goto out;
216 	usleep_range(500, 1000); /* Wait for at least 500us */
217 
218 	/* write/read test for device presence */
219 	ret = ad_sd_read_reg(&st->sd, AD7192_REG_ID, 1, &id);
220 	if (ret)
221 		goto out;
222 
223 	id &= AD7192_ID_MASK;
224 
225 	if (id != st->devid)
226 		dev_warn(&st->sd.spi->dev, "device ID query failed (0x%X)\n",
227 			id);
228 
229 	switch (pdata->clock_source_sel) {
230 	case AD7192_CLK_EXT_MCLK1_2:
231 	case AD7192_CLK_EXT_MCLK2:
232 		st->mclk = AD7192_INT_FREQ_MHz;
233 		break;
234 	case AD7192_CLK_INT:
235 	case AD7192_CLK_INT_CO:
236 		if (pdata->ext_clk_Hz)
237 			st->mclk = pdata->ext_clk_Hz;
238 		else
239 			st->mclk = AD7192_INT_FREQ_MHz;
240 			break;
241 	default:
242 		ret = -EINVAL;
243 		goto out;
244 	}
245 
246 	st->mode = AD7192_MODE_SEL(AD7192_MODE_IDLE) |
247 		AD7192_MODE_CLKSRC(pdata->clock_source_sel) |
248 		AD7192_MODE_RATE(480);
249 
250 	st->conf = AD7192_CONF_GAIN(0);
251 
252 	if (pdata->rej60_en)
253 		st->mode |= AD7192_MODE_REJ60;
254 
255 	if (pdata->sinc3_en)
256 		st->mode |= AD7192_MODE_SINC3;
257 
258 	if (pdata->refin2_en && (st->devid != ID_AD7195))
259 		st->conf |= AD7192_CONF_REFSEL;
260 
261 	if (pdata->chop_en) {
262 		st->conf |= AD7192_CONF_CHOP;
263 		if (pdata->sinc3_en)
264 			st->f_order = 3; /* SINC 3rd order */
265 		else
266 			st->f_order = 4; /* SINC 4th order */
267 	} else {
268 		st->f_order = 1;
269 	}
270 
271 	if (pdata->buf_en)
272 		st->conf |= AD7192_CONF_BUF;
273 
274 	if (pdata->unipolar_en)
275 		st->conf |= AD7192_CONF_UNIPOLAR;
276 
277 	if (pdata->burnout_curr_en)
278 		st->conf |= AD7192_CONF_BURN;
279 
280 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
281 	if (ret)
282 		goto out;
283 
284 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
285 	if (ret)
286 		goto out;
287 
288 	ret = ad7192_calibrate_all(st);
289 	if (ret)
290 		goto out;
291 
292 	/* Populate available ADC input ranges */
293 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
294 		scale_uv = ((u64)st->int_vref_mv * 100000000)
295 			>> (indio_dev->channels[0].scan_type.realbits -
296 			((st->conf & AD7192_CONF_UNIPOLAR) ? 0 : 1));
297 		scale_uv >>= i;
298 
299 		st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
300 		st->scale_avail[i][0] = scale_uv;
301 	}
302 
303 	return 0;
304 out:
305 	dev_err(&st->sd.spi->dev, "setup failed\n");
306 	return ret;
307 }
308 
ad7192_read_frequency(struct device * dev,struct device_attribute * attr,char * buf)309 static ssize_t ad7192_read_frequency(struct device *dev,
310 		struct device_attribute *attr,
311 		char *buf)
312 {
313 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
314 	struct ad7192_state *st = iio_priv(indio_dev);
315 
316 	return sprintf(buf, "%d\n", st->mclk /
317 			(st->f_order * 1024 * AD7192_MODE_RATE(st->mode)));
318 }
319 
ad7192_write_frequency(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)320 static ssize_t ad7192_write_frequency(struct device *dev,
321 		struct device_attribute *attr,
322 		const char *buf,
323 		size_t len)
324 {
325 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
326 	struct ad7192_state *st = iio_priv(indio_dev);
327 	unsigned long lval;
328 	int div, ret;
329 
330 	ret = kstrtoul(buf, 10, &lval);
331 	if (ret)
332 		return ret;
333 	if (lval == 0)
334 		return -EINVAL;
335 
336 	mutex_lock(&indio_dev->mlock);
337 	if (iio_buffer_enabled(indio_dev)) {
338 		mutex_unlock(&indio_dev->mlock);
339 		return -EBUSY;
340 	}
341 
342 	div = st->mclk / (lval * st->f_order * 1024);
343 	if (div < 1 || div > 1023) {
344 		ret = -EINVAL;
345 		goto out;
346 	}
347 
348 	st->mode &= ~AD7192_MODE_RATE(-1);
349 	st->mode |= AD7192_MODE_RATE(div);
350 	ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
351 
352 out:
353 	mutex_unlock(&indio_dev->mlock);
354 
355 	return ret ? ret : len;
356 }
357 
358 static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
359 		ad7192_read_frequency,
360 		ad7192_write_frequency);
361 
ad7192_show_scale_available(struct device * dev,struct device_attribute * attr,char * buf)362 static ssize_t ad7192_show_scale_available(struct device *dev,
363 			struct device_attribute *attr, char *buf)
364 {
365 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
366 	struct ad7192_state *st = iio_priv(indio_dev);
367 	int i, len = 0;
368 
369 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
370 		len += sprintf(buf + len, "%d.%09u ", st->scale_avail[i][0],
371 			       st->scale_avail[i][1]);
372 
373 	len += sprintf(buf + len, "\n");
374 
375 	return len;
376 }
377 
378 static IIO_DEVICE_ATTR_NAMED(in_v_m_v_scale_available,
379 			     in_voltage-voltage_scale_available,
380 			     S_IRUGO, ad7192_show_scale_available, NULL, 0);
381 
382 static IIO_DEVICE_ATTR(in_voltage_scale_available, S_IRUGO,
383 		       ad7192_show_scale_available, NULL, 0);
384 
ad7192_show_ac_excitation(struct device * dev,struct device_attribute * attr,char * buf)385 static ssize_t ad7192_show_ac_excitation(struct device *dev,
386 		struct device_attribute *attr,
387 		char *buf)
388 {
389 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
390 	struct ad7192_state *st = iio_priv(indio_dev);
391 
392 	return sprintf(buf, "%d\n", !!(st->mode & AD7192_MODE_ACX));
393 }
394 
ad7192_show_bridge_switch(struct device * dev,struct device_attribute * attr,char * buf)395 static ssize_t ad7192_show_bridge_switch(struct device *dev,
396 		struct device_attribute *attr,
397 		char *buf)
398 {
399 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
400 	struct ad7192_state *st = iio_priv(indio_dev);
401 
402 	return sprintf(buf, "%d\n", !!(st->gpocon & AD7192_GPOCON_BPDSW));
403 }
404 
ad7192_set(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)405 static ssize_t ad7192_set(struct device *dev,
406 		struct device_attribute *attr,
407 		const char *buf,
408 		size_t len)
409 {
410 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
411 	struct ad7192_state *st = iio_priv(indio_dev);
412 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
413 	int ret;
414 	bool val;
415 
416 	ret = strtobool(buf, &val);
417 	if (ret < 0)
418 		return ret;
419 
420 	mutex_lock(&indio_dev->mlock);
421 	if (iio_buffer_enabled(indio_dev)) {
422 		mutex_unlock(&indio_dev->mlock);
423 		return -EBUSY;
424 	}
425 
426 	switch ((u32) this_attr->address) {
427 	case AD7192_REG_GPOCON:
428 		if (val)
429 			st->gpocon |= AD7192_GPOCON_BPDSW;
430 		else
431 			st->gpocon &= ~AD7192_GPOCON_BPDSW;
432 
433 		ad_sd_write_reg(&st->sd, AD7192_REG_GPOCON, 1, st->gpocon);
434 		break;
435 	case AD7192_REG_MODE:
436 		if (val)
437 			st->mode |= AD7192_MODE_ACX;
438 		else
439 			st->mode &= ~AD7192_MODE_ACX;
440 
441 		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
442 		break;
443 	default:
444 		ret = -EINVAL;
445 	}
446 
447 	mutex_unlock(&indio_dev->mlock);
448 
449 	return ret ? ret : len;
450 }
451 
452 static IIO_DEVICE_ATTR(bridge_switch_en, S_IRUGO | S_IWUSR,
453 		       ad7192_show_bridge_switch, ad7192_set,
454 		       AD7192_REG_GPOCON);
455 
456 static IIO_DEVICE_ATTR(ac_excitation_en, S_IRUGO | S_IWUSR,
457 		       ad7192_show_ac_excitation, ad7192_set,
458 		       AD7192_REG_MODE);
459 
460 static struct attribute *ad7192_attributes[] = {
461 	&iio_dev_attr_sampling_frequency.dev_attr.attr,
462 	&iio_dev_attr_in_v_m_v_scale_available.dev_attr.attr,
463 	&iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
464 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
465 	&iio_dev_attr_ac_excitation_en.dev_attr.attr,
466 	NULL
467 };
468 
469 static const struct attribute_group ad7192_attribute_group = {
470 	.attrs = ad7192_attributes,
471 };
472 
473 static struct attribute *ad7195_attributes[] = {
474 	&iio_dev_attr_sampling_frequency.dev_attr.attr,
475 	&iio_dev_attr_in_v_m_v_scale_available.dev_attr.attr,
476 	&iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
477 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
478 	NULL
479 };
480 
481 static const struct attribute_group ad7195_attribute_group = {
482 	.attrs = ad7195_attributes,
483 };
484 
ad7192_get_temp_scale(bool unipolar)485 static unsigned int ad7192_get_temp_scale(bool unipolar)
486 {
487 	return unipolar ? 2815 * 2 : 2815;
488 }
489 
ad7192_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long m)490 static int ad7192_read_raw(struct iio_dev *indio_dev,
491 			   struct iio_chan_spec const *chan,
492 			   int *val,
493 			   int *val2,
494 			   long m)
495 {
496 	struct ad7192_state *st = iio_priv(indio_dev);
497 	bool unipolar = !!(st->conf & AD7192_CONF_UNIPOLAR);
498 
499 	switch (m) {
500 	case IIO_CHAN_INFO_RAW:
501 		return ad_sigma_delta_single_conversion(indio_dev, chan, val);
502 	case IIO_CHAN_INFO_SCALE:
503 		switch (chan->type) {
504 		case IIO_VOLTAGE:
505 			mutex_lock(&indio_dev->mlock);
506 			*val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
507 			*val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
508 			mutex_unlock(&indio_dev->mlock);
509 			return IIO_VAL_INT_PLUS_NANO;
510 		case IIO_TEMP:
511 			*val = 0;
512 			*val2 = 1000000000 / ad7192_get_temp_scale(unipolar);
513 			return IIO_VAL_INT_PLUS_NANO;
514 		default:
515 			return -EINVAL;
516 		}
517 	case IIO_CHAN_INFO_OFFSET:
518 		if (!unipolar)
519 			*val = -(1 << (chan->scan_type.realbits - 1));
520 		else
521 			*val = 0;
522 		/* Kelvin to Celsius */
523 		if (chan->type == IIO_TEMP)
524 			*val -= 273 * ad7192_get_temp_scale(unipolar);
525 		return IIO_VAL_INT;
526 	}
527 
528 	return -EINVAL;
529 }
530 
ad7192_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)531 static int ad7192_write_raw(struct iio_dev *indio_dev,
532 			       struct iio_chan_spec const *chan,
533 			       int val,
534 			       int val2,
535 			       long mask)
536 {
537 	struct ad7192_state *st = iio_priv(indio_dev);
538 	int ret, i;
539 	unsigned int tmp;
540 
541 	mutex_lock(&indio_dev->mlock);
542 	if (iio_buffer_enabled(indio_dev)) {
543 		mutex_unlock(&indio_dev->mlock);
544 		return -EBUSY;
545 	}
546 
547 	switch (mask) {
548 	case IIO_CHAN_INFO_SCALE:
549 		ret = -EINVAL;
550 		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
551 			if (val2 == st->scale_avail[i][1]) {
552 				ret = 0;
553 				tmp = st->conf;
554 				st->conf &= ~AD7192_CONF_GAIN(-1);
555 				st->conf |= AD7192_CONF_GAIN(i);
556 				if (tmp == st->conf)
557 					break;
558 				ad_sd_write_reg(&st->sd, AD7192_REG_CONF,
559 						 3, st->conf);
560 				ad7192_calibrate_all(st);
561 				break;
562 			}
563 		break;
564 	default:
565 		ret = -EINVAL;
566 	}
567 
568 	mutex_unlock(&indio_dev->mlock);
569 
570 	return ret;
571 }
572 
ad7192_write_raw_get_fmt(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,long mask)573 static int ad7192_write_raw_get_fmt(struct iio_dev *indio_dev,
574 			       struct iio_chan_spec const *chan,
575 			       long mask)
576 {
577 	return IIO_VAL_INT_PLUS_NANO;
578 }
579 
580 static const struct iio_info ad7192_info = {
581 	.read_raw = &ad7192_read_raw,
582 	.write_raw = &ad7192_write_raw,
583 	.write_raw_get_fmt = &ad7192_write_raw_get_fmt,
584 	.attrs = &ad7192_attribute_group,
585 	.validate_trigger = ad_sd_validate_trigger,
586 	.driver_module = THIS_MODULE,
587 };
588 
589 static const struct iio_info ad7195_info = {
590 	.read_raw = &ad7192_read_raw,
591 	.write_raw = &ad7192_write_raw,
592 	.write_raw_get_fmt = &ad7192_write_raw_get_fmt,
593 	.attrs = &ad7195_attribute_group,
594 	.validate_trigger = ad_sd_validate_trigger,
595 	.driver_module = THIS_MODULE,
596 };
597 
598 static const struct iio_chan_spec ad7192_channels[] = {
599 	AD_SD_DIFF_CHANNEL(0, 1, 2, AD7192_CH_AIN1P_AIN2M, 24, 32, 0),
600 	AD_SD_DIFF_CHANNEL(1, 3, 4, AD7192_CH_AIN3P_AIN4M, 24, 32, 0),
601 	AD_SD_TEMP_CHANNEL(2, AD7192_CH_TEMP, 24, 32, 0),
602 	AD_SD_SHORTED_CHANNEL(3, 2, AD7192_CH_AIN2P_AIN2M, 24, 32, 0),
603 	AD_SD_CHANNEL(4, 1, AD7192_CH_AIN1, 24, 32, 0),
604 	AD_SD_CHANNEL(5, 2, AD7192_CH_AIN2, 24, 32, 0),
605 	AD_SD_CHANNEL(6, 3, AD7192_CH_AIN3, 24, 32, 0),
606 	AD_SD_CHANNEL(7, 4, AD7192_CH_AIN4, 24, 32, 0),
607 	IIO_CHAN_SOFT_TIMESTAMP(8),
608 };
609 
ad7192_probe(struct spi_device * spi)610 static int ad7192_probe(struct spi_device *spi)
611 {
612 	const struct ad7192_platform_data *pdata = spi->dev.platform_data;
613 	struct ad7192_state *st;
614 	struct iio_dev *indio_dev;
615 	int ret, voltage_uv = 0;
616 
617 	if (!pdata) {
618 		dev_err(&spi->dev, "no platform data?\n");
619 		return -ENODEV;
620 	}
621 
622 	if (!spi->irq) {
623 		dev_err(&spi->dev, "no IRQ?\n");
624 		return -ENODEV;
625 	}
626 
627 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
628 	if (indio_dev == NULL)
629 		return -ENOMEM;
630 
631 	st = iio_priv(indio_dev);
632 
633 	st->reg = devm_regulator_get(&spi->dev, "vcc");
634 	if (!IS_ERR(st->reg)) {
635 		ret = regulator_enable(st->reg);
636 		if (ret)
637 			return ret;
638 
639 		voltage_uv = regulator_get_voltage(st->reg);
640 	}
641 
642 	if (pdata && pdata->vref_mv)
643 		st->int_vref_mv = pdata->vref_mv;
644 	else if (voltage_uv)
645 		st->int_vref_mv = voltage_uv / 1000;
646 	else
647 		dev_warn(&spi->dev, "reference voltage undefined\n");
648 
649 	spi_set_drvdata(spi, indio_dev);
650 	st->devid = spi_get_device_id(spi)->driver_data;
651 	indio_dev->dev.parent = &spi->dev;
652 	indio_dev->name = spi_get_device_id(spi)->name;
653 	indio_dev->modes = INDIO_DIRECT_MODE;
654 	indio_dev->channels = ad7192_channels;
655 	indio_dev->num_channels = ARRAY_SIZE(ad7192_channels);
656 	if (st->devid == ID_AD7195)
657 		indio_dev->info = &ad7195_info;
658 	else
659 		indio_dev->info = &ad7192_info;
660 
661 	ad_sd_init(&st->sd, indio_dev, spi, &ad7192_sigma_delta_info);
662 
663 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
664 	if (ret)
665 		goto error_disable_reg;
666 
667 	ret = ad7192_setup(st, pdata);
668 	if (ret)
669 		goto error_remove_trigger;
670 
671 	ret = iio_device_register(indio_dev);
672 	if (ret < 0)
673 		goto error_remove_trigger;
674 	return 0;
675 
676 error_remove_trigger:
677 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
678 error_disable_reg:
679 	if (!IS_ERR(st->reg))
680 		regulator_disable(st->reg);
681 
682 	return ret;
683 }
684 
ad7192_remove(struct spi_device * spi)685 static int ad7192_remove(struct spi_device *spi)
686 {
687 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
688 	struct ad7192_state *st = iio_priv(indio_dev);
689 
690 	iio_device_unregister(indio_dev);
691 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
692 
693 	if (!IS_ERR(st->reg))
694 		regulator_disable(st->reg);
695 
696 	return 0;
697 }
698 
699 static const struct spi_device_id ad7192_id[] = {
700 	{"ad7190", ID_AD7190},
701 	{"ad7192", ID_AD7192},
702 	{"ad7195", ID_AD7195},
703 	{}
704 };
705 MODULE_DEVICE_TABLE(spi, ad7192_id);
706 
707 static struct spi_driver ad7192_driver = {
708 	.driver = {
709 		.name	= "ad7192",
710 		.owner	= THIS_MODULE,
711 	},
712 	.probe		= ad7192_probe,
713 	.remove		= ad7192_remove,
714 	.id_table	= ad7192_id,
715 };
716 module_spi_driver(ad7192_driver);
717 
718 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
719 MODULE_DESCRIPTION("Analog Devices AD7190, AD7192, AD7195 ADC");
720 MODULE_LICENSE("GPL v2");
721