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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		(1 << 7) /* Write Enable */
45 #define AD7192_COMM_WRITE	(0 << 6) /* Write Operation */
46 #define AD7192_COMM_READ	(1 << 6) /* Read Operation */
47 #define AD7192_COMM_ADDR(x)	(((x) & 0x7) << 3) /* Register Address */
48 #define AD7192_COMM_CREAD	(1 << 2) /* Continuous Read of Data Register */
49 
50 /* Status Register Bit Designations (AD7192_REG_STAT) */
51 #define AD7192_STAT_RDY		(1 << 7) /* Ready */
52 #define AD7192_STAT_ERR		(1 << 6) /* Error (Overrange, Underrange) */
53 #define AD7192_STAT_NOREF	(1 << 5) /* Error no external reference */
54 #define AD7192_STAT_PARITY	(1 << 4) /* Parity */
55 #define AD7192_STAT_CH3		(1 << 2) /* Channel 3 */
56 #define AD7192_STAT_CH2		(1 << 1) /* Channel 2 */
57 #define AD7192_STAT_CH1		(1 << 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	(1 << 20) /* Status Register transmission */
63 #define AD7192_MODE_CLKSRC(x)	(((x) & 0x3) << 18) /* Clock Source Select */
64 #define AD7192_MODE_SINC3	(1 << 15) /* SINC3 Filter Select */
65 #define AD7192_MODE_ACX		(1 << 14) /* AC excitation enable(AD7195 only)*/
66 #define AD7192_MODE_ENPAR	(1 << 13) /* Parity Enable */
67 #define AD7192_MODE_CLKDIV	(1 << 12) /* Clock divide by 2 (AD7190/2 only)*/
68 #define AD7192_MODE_SCYCLE	(1 << 11) /* Single cycle conversion */
69 #define AD7192_MODE_REJ60	(1 << 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	(1 << 23) /* CHOP enable */
95 #define AD7192_CONF_REFSEL	(1 << 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	(1 << 7) /* Burnout current enable */
99 #define AD7192_CONF_REFDET	(1 << 6) /* Reference detect enable */
100 #define AD7192_CONF_BUF		(1 << 4) /* Buffered Mode Enable */
101 #define AD7192_CONF_UNIPOLAR	(1 << 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	(1 << 6) /* Bridge power-down switch enable */
121 #define AD7192_GPOCON_GP32EN	(1 << 5) /* Digital Output P3 and P2 enable */
122 #define AD7192_GPOCON_GP10EN	(1 << 4) /* Digital Output P1 and P0 enable */
123 #define AD7192_GPOCON_P3DAT	(1 << 3) /* P3 state */
124 #define AD7192_GPOCON_P2DAT	(1 << 2) /* P2 state */
125 #define AD7192_GPOCON_P1DAT	(1 << 1) /* P1 state */
126 #define AD7192_GPOCON_P0DAT	(1 << 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 	msleep(1); /* 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", id);
227 
228 	switch (pdata->clock_source_sel) {
229 	case AD7192_CLK_EXT_MCLK1_2:
230 	case AD7192_CLK_EXT_MCLK2:
231 		st->mclk = AD7192_INT_FREQ_MHz;
232 		break;
233 	case AD7192_CLK_INT:
234 	case AD7192_CLK_INT_CO:
235 		if (pdata->ext_clk_Hz)
236 			st->mclk = pdata->ext_clk_Hz;
237 		else
238 			st->mclk = AD7192_INT_FREQ_MHz;
239 			break;
240 	default:
241 		ret = -EINVAL;
242 		goto out;
243 	}
244 
245 	st->mode = AD7192_MODE_SEL(AD7192_MODE_IDLE) |
246 		AD7192_MODE_CLKSRC(pdata->clock_source_sel) |
247 		AD7192_MODE_RATE(480);
248 
249 	st->conf = AD7192_CONF_GAIN(0);
250 
251 	if (pdata->rej60_en)
252 		st->mode |= AD7192_MODE_REJ60;
253 
254 	if (pdata->sinc3_en)
255 		st->mode |= AD7192_MODE_SINC3;
256 
257 	if (pdata->refin2_en && (st->devid != ID_AD7195))
258 		st->conf |= AD7192_CONF_REFSEL;
259 
260 	if (pdata->chop_en) {
261 		st->conf |= AD7192_CONF_CHOP;
262 		if (pdata->sinc3_en)
263 			st->f_order = 3; /* SINC 3rd order */
264 		else
265 			st->f_order = 4; /* SINC 4th order */
266 	} else {
267 		st->f_order = 1;
268 	}
269 
270 	if (pdata->buf_en)
271 		st->conf |= AD7192_CONF_BUF;
272 
273 	if (pdata->unipolar_en)
274 		st->conf |= AD7192_CONF_UNIPOLAR;
275 
276 	if (pdata->burnout_curr_en)
277 		st->conf |= AD7192_CONF_BURN;
278 
279 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
280 	if (ret)
281 		goto out;
282 
283 	ret = ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
284 	if (ret)
285 		goto out;
286 
287 	ret = ad7192_calibrate_all(st);
288 	if (ret)
289 		goto out;
290 
291 	/* Populate available ADC input ranges */
292 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
293 		scale_uv = ((u64)st->int_vref_mv * 100000000)
294 			>> (indio_dev->channels[0].scan_type.realbits -
295 			((st->conf & AD7192_CONF_UNIPOLAR) ? 0 : 1));
296 		scale_uv >>= i;
297 
298 		st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
299 		st->scale_avail[i][0] = scale_uv;
300 	}
301 
302 	return 0;
303 out:
304 	dev_err(&st->sd.spi->dev, "setup failed\n");
305 	return ret;
306 }
307 
ad7192_read_frequency(struct device * dev,struct device_attribute * attr,char * buf)308 static ssize_t ad7192_read_frequency(struct device *dev,
309 		struct device_attribute *attr,
310 		char *buf)
311 {
312 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
313 	struct ad7192_state *st = iio_priv(indio_dev);
314 
315 	return sprintf(buf, "%d\n", st->mclk /
316 			(st->f_order * 1024 * AD7192_MODE_RATE(st->mode)));
317 }
318 
ad7192_write_frequency(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)319 static ssize_t ad7192_write_frequency(struct device *dev,
320 		struct device_attribute *attr,
321 		const char *buf,
322 		size_t len)
323 {
324 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
325 	struct ad7192_state *st = iio_priv(indio_dev);
326 	unsigned long lval;
327 	int div, ret;
328 
329 	ret = strict_strtoul(buf, 10, &lval);
330 	if (ret)
331 		return ret;
332 	if (lval == 0)
333 		return -EINVAL;
334 
335 	mutex_lock(&indio_dev->mlock);
336 	if (iio_buffer_enabled(indio_dev)) {
337 		mutex_unlock(&indio_dev->mlock);
338 		return -EBUSY;
339 	}
340 
341 	div = st->mclk / (lval * st->f_order * 1024);
342 	if (div < 1 || div > 1023) {
343 		ret = -EINVAL;
344 		goto out;
345 	}
346 
347 	st->mode &= ~AD7192_MODE_RATE(-1);
348 	st->mode |= AD7192_MODE_RATE(div);
349 	ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
350 
351 out:
352 	mutex_unlock(&indio_dev->mlock);
353 
354 	return ret ? ret : len;
355 }
356 
357 static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
358 		ad7192_read_frequency,
359 		ad7192_write_frequency);
360 
ad7192_show_scale_available(struct device * dev,struct device_attribute * attr,char * buf)361 static ssize_t ad7192_show_scale_available(struct device *dev,
362 			struct device_attribute *attr, char *buf)
363 {
364 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
365 	struct ad7192_state *st = iio_priv(indio_dev);
366 	int i, len = 0;
367 
368 	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
369 		len += sprintf(buf + len, "%d.%09u ", st->scale_avail[i][0],
370 			       st->scale_avail[i][1]);
371 
372 	len += sprintf(buf + len, "\n");
373 
374 	return len;
375 }
376 
377 static IIO_DEVICE_ATTR_NAMED(in_v_m_v_scale_available,
378 			     in_voltage-voltage_scale_available,
379 			     S_IRUGO, ad7192_show_scale_available, NULL, 0);
380 
381 static IIO_DEVICE_ATTR(in_voltage_scale_available, S_IRUGO,
382 		       ad7192_show_scale_available, NULL, 0);
383 
ad7192_show_ac_excitation(struct device * dev,struct device_attribute * attr,char * buf)384 static ssize_t ad7192_show_ac_excitation(struct device *dev,
385 		struct device_attribute *attr,
386 		char *buf)
387 {
388 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
389 	struct ad7192_state *st = iio_priv(indio_dev);
390 
391 	return sprintf(buf, "%d\n", !!(st->mode & AD7192_MODE_ACX));
392 }
393 
ad7192_show_bridge_switch(struct device * dev,struct device_attribute * attr,char * buf)394 static ssize_t ad7192_show_bridge_switch(struct device *dev,
395 		struct device_attribute *attr,
396 		char *buf)
397 {
398 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
399 	struct ad7192_state *st = iio_priv(indio_dev);
400 
401 	return sprintf(buf, "%d\n", !!(st->gpocon & AD7192_GPOCON_BPDSW));
402 }
403 
ad7192_set(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)404 static ssize_t ad7192_set(struct device *dev,
405 		struct device_attribute *attr,
406 		const char *buf,
407 		size_t len)
408 {
409 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
410 	struct ad7192_state *st = iio_priv(indio_dev);
411 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
412 	int ret;
413 	bool val;
414 
415 	ret = strtobool(buf, &val);
416 	if (ret < 0)
417 		return ret;
418 
419 	mutex_lock(&indio_dev->mlock);
420 	if (iio_buffer_enabled(indio_dev)) {
421 		mutex_unlock(&indio_dev->mlock);
422 		return -EBUSY;
423 	}
424 
425 	switch ((u32) this_attr->address) {
426 	case AD7192_REG_GPOCON:
427 		if (val)
428 			st->gpocon |= AD7192_GPOCON_BPDSW;
429 		else
430 			st->gpocon &= ~AD7192_GPOCON_BPDSW;
431 
432 		ad_sd_write_reg(&st->sd, AD7192_REG_GPOCON, 1, st->gpocon);
433 		break;
434 	case AD7192_REG_MODE:
435 		if (val)
436 			st->mode |= AD7192_MODE_ACX;
437 		else
438 			st->mode &= ~AD7192_MODE_ACX;
439 
440 		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
441 		break;
442 	default:
443 		ret = -EINVAL;
444 	}
445 
446 	mutex_unlock(&indio_dev->mlock);
447 
448 	return ret ? ret : len;
449 }
450 
451 static IIO_DEVICE_ATTR(bridge_switch_en, S_IRUGO | S_IWUSR,
452 		       ad7192_show_bridge_switch, ad7192_set,
453 		       AD7192_REG_GPOCON);
454 
455 static IIO_DEVICE_ATTR(ac_excitation_en, S_IRUGO | S_IWUSR,
456 		       ad7192_show_ac_excitation, ad7192_set,
457 		       AD7192_REG_MODE);
458 
459 static struct attribute *ad7192_attributes[] = {
460 	&iio_dev_attr_sampling_frequency.dev_attr.attr,
461 	&iio_dev_attr_in_v_m_v_scale_available.dev_attr.attr,
462 	&iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
463 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
464 	&iio_dev_attr_ac_excitation_en.dev_attr.attr,
465 	NULL
466 };
467 
468 static const struct attribute_group ad7192_attribute_group = {
469 	.attrs = ad7192_attributes,
470 };
471 
472 static struct attribute *ad7195_attributes[] = {
473 	&iio_dev_attr_sampling_frequency.dev_attr.attr,
474 	&iio_dev_attr_in_v_m_v_scale_available.dev_attr.attr,
475 	&iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
476 	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
477 	NULL
478 };
479 
480 static const struct attribute_group ad7195_attribute_group = {
481 	.attrs = ad7195_attributes,
482 };
483 
ad7192_get_temp_scale(bool unipolar)484 static unsigned int ad7192_get_temp_scale(bool unipolar)
485 {
486 	return unipolar ? 2815 * 2 : 2815;
487 }
488 
ad7192_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long m)489 static int ad7192_read_raw(struct iio_dev *indio_dev,
490 			   struct iio_chan_spec const *chan,
491 			   int *val,
492 			   int *val2,
493 			   long m)
494 {
495 	struct ad7192_state *st = iio_priv(indio_dev);
496 	bool unipolar = !!(st->conf & AD7192_CONF_UNIPOLAR);
497 
498 	switch (m) {
499 	case IIO_CHAN_INFO_RAW:
500 		return ad_sigma_delta_single_conversion(indio_dev, chan, val);
501 	case IIO_CHAN_INFO_SCALE:
502 		switch (chan->type) {
503 		case IIO_VOLTAGE:
504 			mutex_lock(&indio_dev->mlock);
505 			*val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
506 			*val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
507 			mutex_unlock(&indio_dev->mlock);
508 			return IIO_VAL_INT_PLUS_NANO;
509 		case IIO_TEMP:
510 			*val = 0;
511 			*val2 = 1000000000 / ad7192_get_temp_scale(unipolar);
512 			return IIO_VAL_INT_PLUS_NANO;
513 		default:
514 			return -EINVAL;
515 		}
516 	case IIO_CHAN_INFO_OFFSET:
517 		if (!unipolar)
518 			*val = -(1 << (chan->scan_type.realbits - 1));
519 		else
520 			*val = 0;
521 		/* Kelvin to Celsius */
522 		if (chan->type == IIO_TEMP)
523 			*val -= 273 * ad7192_get_temp_scale(unipolar);
524 		return IIO_VAL_INT;
525 	}
526 
527 	return -EINVAL;
528 }
529 
ad7192_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)530 static int ad7192_write_raw(struct iio_dev *indio_dev,
531 			       struct iio_chan_spec const *chan,
532 			       int val,
533 			       int val2,
534 			       long mask)
535 {
536 	struct ad7192_state *st = iio_priv(indio_dev);
537 	int ret, i;
538 	unsigned int tmp;
539 
540 	mutex_lock(&indio_dev->mlock);
541 	if (iio_buffer_enabled(indio_dev)) {
542 		mutex_unlock(&indio_dev->mlock);
543 		return -EBUSY;
544 	}
545 
546 	switch (mask) {
547 	case IIO_CHAN_INFO_SCALE:
548 		ret = -EINVAL;
549 		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
550 			if (val2 == st->scale_avail[i][1]) {
551 				ret = 0;
552 				tmp = st->conf;
553 				st->conf &= ~AD7192_CONF_GAIN(-1);
554 				st->conf |= AD7192_CONF_GAIN(i);
555 				if (tmp == st->conf)
556 					break;
557 				ad_sd_write_reg(&st->sd, AD7192_REG_CONF,
558 						 3, st->conf);
559 				ad7192_calibrate_all(st);
560 				break;
561 			}
562 		break;
563 	default:
564 		ret = -EINVAL;
565 	}
566 
567 	mutex_unlock(&indio_dev->mlock);
568 
569 	return ret;
570 }
571 
ad7192_write_raw_get_fmt(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,long mask)572 static int ad7192_write_raw_get_fmt(struct iio_dev *indio_dev,
573 			       struct iio_chan_spec const *chan,
574 			       long mask)
575 {
576 	return IIO_VAL_INT_PLUS_NANO;
577 }
578 
579 static const struct iio_info ad7192_info = {
580 	.read_raw = &ad7192_read_raw,
581 	.write_raw = &ad7192_write_raw,
582 	.write_raw_get_fmt = &ad7192_write_raw_get_fmt,
583 	.attrs = &ad7192_attribute_group,
584 	.validate_trigger = ad_sd_validate_trigger,
585 	.driver_module = THIS_MODULE,
586 };
587 
588 static const struct iio_info ad7195_info = {
589 	.read_raw = &ad7192_read_raw,
590 	.write_raw = &ad7192_write_raw,
591 	.write_raw_get_fmt = &ad7192_write_raw_get_fmt,
592 	.attrs = &ad7195_attribute_group,
593 	.validate_trigger = ad_sd_validate_trigger,
594 	.driver_module = THIS_MODULE,
595 };
596 
597 static const struct iio_chan_spec ad7192_channels[] = {
598 	AD_SD_DIFF_CHANNEL(0, 1, 2, AD7192_CH_AIN1P_AIN2M, 24, 32, 0),
599 	AD_SD_DIFF_CHANNEL(1, 3, 4, AD7192_CH_AIN3P_AIN4M, 24, 32, 0),
600 	AD_SD_TEMP_CHANNEL(2, AD7192_CH_TEMP, 24, 32, 0),
601 	AD_SD_SHORTED_CHANNEL(3, 2, AD7192_CH_AIN2P_AIN2M, 24, 32, 0),
602 	AD_SD_CHANNEL(4, 1, AD7192_CH_AIN1, 24, 32, 0),
603 	AD_SD_CHANNEL(5, 2, AD7192_CH_AIN2, 24, 32, 0),
604 	AD_SD_CHANNEL(6, 3, AD7192_CH_AIN3, 24, 32, 0),
605 	AD_SD_CHANNEL(7, 4, AD7192_CH_AIN4, 24, 32, 0),
606 	IIO_CHAN_SOFT_TIMESTAMP(8),
607 };
608 
ad7192_probe(struct spi_device * spi)609 static int ad7192_probe(struct spi_device *spi)
610 {
611 	const struct ad7192_platform_data *pdata = spi->dev.platform_data;
612 	struct ad7192_state *st;
613 	struct iio_dev *indio_dev;
614 	int ret , voltage_uv = 0;
615 
616 	if (!pdata) {
617 		dev_err(&spi->dev, "no platform data?\n");
618 		return -ENODEV;
619 	}
620 
621 	if (!spi->irq) {
622 		dev_err(&spi->dev, "no IRQ?\n");
623 		return -ENODEV;
624 	}
625 
626 	indio_dev = iio_device_alloc(sizeof(*st));
627 	if (indio_dev == NULL)
628 		return -ENOMEM;
629 
630 	st = iio_priv(indio_dev);
631 
632 	st->reg = regulator_get(&spi->dev, "vcc");
633 	if (!IS_ERR(st->reg)) {
634 		ret = regulator_enable(st->reg);
635 		if (ret)
636 			goto error_put_reg;
637 
638 		voltage_uv = regulator_get_voltage(st->reg);
639 	}
640 
641 	if (pdata && pdata->vref_mv)
642 		st->int_vref_mv = pdata->vref_mv;
643 	else if (voltage_uv)
644 		st->int_vref_mv = voltage_uv / 1000;
645 	else
646 		dev_warn(&spi->dev, "reference voltage undefined\n");
647 
648 	spi_set_drvdata(spi, indio_dev);
649 	st->devid = spi_get_device_id(spi)->driver_data;
650 	indio_dev->dev.parent = &spi->dev;
651 	indio_dev->name = spi_get_device_id(spi)->name;
652 	indio_dev->modes = INDIO_DIRECT_MODE;
653 	indio_dev->channels = ad7192_channels;
654 	indio_dev->num_channels = ARRAY_SIZE(ad7192_channels);
655 	if (st->devid == ID_AD7195)
656 		indio_dev->info = &ad7195_info;
657 	else
658 		indio_dev->info = &ad7192_info;
659 
660 	ad_sd_init(&st->sd, indio_dev, spi, &ad7192_sigma_delta_info);
661 
662 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
663 	if (ret)
664 		goto error_disable_reg;
665 
666 	ret = ad7192_setup(st, pdata);
667 	if (ret)
668 		goto error_remove_trigger;
669 
670 	ret = iio_device_register(indio_dev);
671 	if (ret < 0)
672 		goto error_remove_trigger;
673 	return 0;
674 
675 error_remove_trigger:
676 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
677 error_disable_reg:
678 	if (!IS_ERR(st->reg))
679 		regulator_disable(st->reg);
680 error_put_reg:
681 	if (!IS_ERR(st->reg))
682 		regulator_put(st->reg);
683 
684 	iio_device_free(indio_dev);
685 
686 	return ret;
687 }
688 
ad7192_remove(struct spi_device * spi)689 static int ad7192_remove(struct spi_device *spi)
690 {
691 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
692 	struct ad7192_state *st = iio_priv(indio_dev);
693 
694 	iio_device_unregister(indio_dev);
695 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
696 
697 	if (!IS_ERR(st->reg)) {
698 		regulator_disable(st->reg);
699 		regulator_put(st->reg);
700 	}
701 
702 	return 0;
703 }
704 
705 static const struct spi_device_id ad7192_id[] = {
706 	{"ad7190", ID_AD7190},
707 	{"ad7192", ID_AD7192},
708 	{"ad7195", ID_AD7195},
709 	{}
710 };
711 MODULE_DEVICE_TABLE(spi, ad7192_id);
712 
713 static struct spi_driver ad7192_driver = {
714 	.driver = {
715 		.name	= "ad7192",
716 		.owner	= THIS_MODULE,
717 	},
718 	.probe		= ad7192_probe,
719 	.remove		= ad7192_remove,
720 	.id_table	= ad7192_id,
721 };
722 module_spi_driver(ad7192_driver);
723 
724 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
725 MODULE_DESCRIPTION("Analog Devices AD7190, AD7192, AD7195 ADC");
726 MODULE_LICENSE("GPL v2");
727