xref: /openbmc/linux/drivers/iio/adc/twl4030-madc.c (revision 56a0eccd)
1 /*
2  *
3  * TWL4030 MADC module driver-This driver monitors the real time
4  * conversion of analog signals like battery temperature,
5  * battery type, battery level etc.
6  *
7  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
8  * J Keerthy <j-keerthy@ti.com>
9  *
10  * Based on twl4030-madc.c
11  * Copyright (C) 2008 Nokia Corporation
12  * Mikko Ylinen <mikko.k.ylinen@nokia.com>
13  *
14  * Amit Kucheria <amit.kucheria@canonical.com>
15  *
16  * This program is free software; you can redistribute it and/or
17  * modify it under the terms of the GNU General Public License
18  * version 2 as published by the Free Software Foundation.
19  *
20  * This program is distributed in the hope that it will be useful, but
21  * WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
23  * General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program; if not, write to the Free Software
27  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
28  * 02110-1301 USA
29  *
30  */
31 
32 #include <linux/device.h>
33 #include <linux/interrupt.h>
34 #include <linux/kernel.h>
35 #include <linux/delay.h>
36 #include <linux/platform_device.h>
37 #include <linux/slab.h>
38 #include <linux/i2c/twl.h>
39 #include <linux/i2c/twl4030-madc.h>
40 #include <linux/module.h>
41 #include <linux/stddef.h>
42 #include <linux/mutex.h>
43 #include <linux/bitops.h>
44 #include <linux/jiffies.h>
45 #include <linux/types.h>
46 #include <linux/gfp.h>
47 #include <linux/err.h>
48 #include <linux/regulator/consumer.h>
49 
50 #include <linux/iio/iio.h>
51 
52 #define TWL4030_USB_SEL_MADC_MCPC	(1<<3)
53 #define TWL4030_USB_CARKIT_ANA_CTRL	0xBB
54 
55 /**
56  * struct twl4030_madc_data - a container for madc info
57  * @dev:		Pointer to device structure for madc
58  * @lock:		Mutex protecting this data structure
59  * @regulator:		Pointer to bias regulator for madc
60  * @requests:		Array of request struct corresponding to SW1, SW2 and RT
61  * @use_second_irq:	IRQ selection (main or co-processor)
62  * @imr:		Interrupt mask register of MADC
63  * @isr:		Interrupt status register of MADC
64  */
65 struct twl4030_madc_data {
66 	struct device *dev;
67 	struct mutex lock;	/* mutex protecting this data structure */
68 	struct regulator *usb3v1;
69 	struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
70 	bool use_second_irq;
71 	u8 imr;
72 	u8 isr;
73 };
74 
75 static int twl4030_madc_read(struct iio_dev *iio_dev,
76 			     const struct iio_chan_spec *chan,
77 			     int *val, int *val2, long mask)
78 {
79 	struct twl4030_madc_data *madc = iio_priv(iio_dev);
80 	struct twl4030_madc_request req;
81 	int ret;
82 
83 	req.method = madc->use_second_irq ? TWL4030_MADC_SW2 : TWL4030_MADC_SW1;
84 
85 	req.channels = BIT(chan->channel);
86 	req.active = false;
87 	req.func_cb = NULL;
88 	req.type = TWL4030_MADC_WAIT;
89 	req.raw = !(mask == IIO_CHAN_INFO_PROCESSED);
90 	req.do_avg = (mask == IIO_CHAN_INFO_AVERAGE_RAW);
91 
92 	ret = twl4030_madc_conversion(&req);
93 	if (ret < 0)
94 		return ret;
95 
96 	*val = req.rbuf[chan->channel];
97 
98 	return IIO_VAL_INT;
99 }
100 
101 static const struct iio_info twl4030_madc_iio_info = {
102 	.read_raw = &twl4030_madc_read,
103 	.driver_module = THIS_MODULE,
104 };
105 
106 #define TWL4030_ADC_CHANNEL(_channel, _type, _name) {	\
107 	.type = _type,					\
108 	.channel = _channel,				\
109 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |  \
110 			      BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \
111 			      BIT(IIO_CHAN_INFO_PROCESSED), \
112 	.datasheet_name = _name,			\
113 	.indexed = 1,					\
114 }
115 
116 static const struct iio_chan_spec twl4030_madc_iio_channels[] = {
117 	TWL4030_ADC_CHANNEL(0, IIO_VOLTAGE, "ADCIN0"),
118 	TWL4030_ADC_CHANNEL(1, IIO_TEMP, "ADCIN1"),
119 	TWL4030_ADC_CHANNEL(2, IIO_VOLTAGE, "ADCIN2"),
120 	TWL4030_ADC_CHANNEL(3, IIO_VOLTAGE, "ADCIN3"),
121 	TWL4030_ADC_CHANNEL(4, IIO_VOLTAGE, "ADCIN4"),
122 	TWL4030_ADC_CHANNEL(5, IIO_VOLTAGE, "ADCIN5"),
123 	TWL4030_ADC_CHANNEL(6, IIO_VOLTAGE, "ADCIN6"),
124 	TWL4030_ADC_CHANNEL(7, IIO_VOLTAGE, "ADCIN7"),
125 	TWL4030_ADC_CHANNEL(8, IIO_VOLTAGE, "ADCIN8"),
126 	TWL4030_ADC_CHANNEL(9, IIO_VOLTAGE, "ADCIN9"),
127 	TWL4030_ADC_CHANNEL(10, IIO_CURRENT, "ADCIN10"),
128 	TWL4030_ADC_CHANNEL(11, IIO_VOLTAGE, "ADCIN11"),
129 	TWL4030_ADC_CHANNEL(12, IIO_VOLTAGE, "ADCIN12"),
130 	TWL4030_ADC_CHANNEL(13, IIO_VOLTAGE, "ADCIN13"),
131 	TWL4030_ADC_CHANNEL(14, IIO_VOLTAGE, "ADCIN14"),
132 	TWL4030_ADC_CHANNEL(15, IIO_VOLTAGE, "ADCIN15"),
133 };
134 
135 static struct twl4030_madc_data *twl4030_madc;
136 
137 struct twl4030_prescale_divider_ratios {
138 	s16 numerator;
139 	s16 denominator;
140 };
141 
142 static const struct twl4030_prescale_divider_ratios
143 twl4030_divider_ratios[16] = {
144 	{1, 1},		/* CHANNEL 0 No Prescaler */
145 	{1, 1},		/* CHANNEL 1 No Prescaler */
146 	{6, 10},	/* CHANNEL 2 */
147 	{6, 10},	/* CHANNEL 3 */
148 	{6, 10},	/* CHANNEL 4 */
149 	{6, 10},	/* CHANNEL 5 */
150 	{6, 10},	/* CHANNEL 6 */
151 	{6, 10},	/* CHANNEL 7 */
152 	{3, 14},	/* CHANNEL 8 */
153 	{1, 3},		/* CHANNEL 9 */
154 	{1, 1},		/* CHANNEL 10 No Prescaler */
155 	{15, 100},	/* CHANNEL 11 */
156 	{1, 4},		/* CHANNEL 12 */
157 	{1, 1},		/* CHANNEL 13 Reserved channels */
158 	{1, 1},		/* CHANNEL 14 Reseved channels */
159 	{5, 11},	/* CHANNEL 15 */
160 };
161 
162 
163 /* Conversion table from -3 to 55 degrees Celcius */
164 static int twl4030_therm_tbl[] = {
165 	30800,	29500,	28300,	27100,
166 	26000,	24900,	23900,	22900,	22000,	21100,	20300,	19400,	18700,
167 	17900,	17200,	16500,	15900,	15300,	14700,	14100,	13600,	13100,
168 	12600,	12100,	11600,	11200,	10800,	10400,	10000,	9630,	9280,
169 	8950,	8620,	8310,	8020,	7730,	7460,	7200,	6950,	6710,
170 	6470,	6250,	6040,	5830,	5640,	5450,	5260,	5090,	4920,
171 	4760,	4600,	4450,	4310,	4170,	4040,	3910,	3790,	3670,
172 	3550
173 };
174 
175 /*
176  * Structure containing the registers
177  * of different conversion methods supported by MADC.
178  * Hardware or RT real time conversion request initiated by external host
179  * processor for RT Signal conversions.
180  * External host processors can also request for non RT conversions
181  * SW1 and SW2 software conversions also called asynchronous or GPC request.
182  */
183 static
184 const struct twl4030_madc_conversion_method twl4030_conversion_methods[] = {
185 	[TWL4030_MADC_RT] = {
186 			     .sel = TWL4030_MADC_RTSELECT_LSB,
187 			     .avg = TWL4030_MADC_RTAVERAGE_LSB,
188 			     .rbase = TWL4030_MADC_RTCH0_LSB,
189 			     },
190 	[TWL4030_MADC_SW1] = {
191 			      .sel = TWL4030_MADC_SW1SELECT_LSB,
192 			      .avg = TWL4030_MADC_SW1AVERAGE_LSB,
193 			      .rbase = TWL4030_MADC_GPCH0_LSB,
194 			      .ctrl = TWL4030_MADC_CTRL_SW1,
195 			      },
196 	[TWL4030_MADC_SW2] = {
197 			      .sel = TWL4030_MADC_SW2SELECT_LSB,
198 			      .avg = TWL4030_MADC_SW2AVERAGE_LSB,
199 			      .rbase = TWL4030_MADC_GPCH0_LSB,
200 			      .ctrl = TWL4030_MADC_CTRL_SW2,
201 			      },
202 };
203 
204 /**
205  * twl4030_madc_channel_raw_read() - Function to read a particular channel value
206  * @madc:	pointer to struct twl4030_madc_data
207  * @reg:	lsb of ADC Channel
208  *
209  * Return: 0 on success, an error code otherwise.
210  */
211 static int twl4030_madc_channel_raw_read(struct twl4030_madc_data *madc, u8 reg)
212 {
213 	u16 val;
214 	int ret;
215 	/*
216 	 * For each ADC channel, we have MSB and LSB register pair. MSB address
217 	 * is always LSB address+1. reg parameter is the address of LSB register
218 	 */
219 	ret = twl_i2c_read_u16(TWL4030_MODULE_MADC, &val, reg);
220 	if (ret) {
221 		dev_err(madc->dev, "unable to read register 0x%X\n", reg);
222 		return ret;
223 	}
224 
225 	return (int)(val >> 6);
226 }
227 
228 /*
229  * Return battery temperature in degrees Celsius
230  * Or < 0 on failure.
231  */
232 static int twl4030battery_temperature(int raw_volt)
233 {
234 	u8 val;
235 	int temp, curr, volt, res, ret;
236 
237 	volt = (raw_volt * TEMP_STEP_SIZE) / TEMP_PSR_R;
238 	/* Getting and calculating the supply current in micro amperes */
239 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val,
240 		REG_BCICTL2);
241 	if (ret < 0)
242 		return ret;
243 
244 	curr = ((val & TWL4030_BCI_ITHSENS) + 1) * 10;
245 	/* Getting and calculating the thermistor resistance in ohms */
246 	res = volt * 1000 / curr;
247 	/* calculating temperature */
248 	for (temp = 58; temp >= 0; temp--) {
249 		int actual = twl4030_therm_tbl[temp];
250 		if ((actual - res) >= 0)
251 			break;
252 	}
253 
254 	return temp + 1;
255 }
256 
257 static int twl4030battery_current(int raw_volt)
258 {
259 	int ret;
260 	u8 val;
261 
262 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val,
263 		TWL4030_BCI_BCICTL1);
264 	if (ret)
265 		return ret;
266 	if (val & TWL4030_BCI_CGAIN) /* slope of 0.44 mV/mA */
267 		return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R1;
268 	else /* slope of 0.88 mV/mA */
269 		return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R2;
270 }
271 
272 /*
273  * Function to read channel values
274  * @madc - pointer to twl4030_madc_data struct
275  * @reg_base - Base address of the first channel
276  * @Channels - 16 bit bitmap. If the bit is set, channel's value is read
277  * @buf - The channel values are stored here. if read fails error
278  * @raw - Return raw values without conversion
279  * value is stored
280  * Returns the number of successfully read channels.
281  */
282 static int twl4030_madc_read_channels(struct twl4030_madc_data *madc,
283 				      u8 reg_base, unsigned
284 				      long channels, int *buf,
285 				      bool raw)
286 {
287 	int count = 0;
288 	int i;
289 	u8 reg;
290 
291 	for_each_set_bit(i, &channels, TWL4030_MADC_MAX_CHANNELS) {
292 		reg = reg_base + (2 * i);
293 		buf[i] = twl4030_madc_channel_raw_read(madc, reg);
294 		if (buf[i] < 0) {
295 			dev_err(madc->dev, "Unable to read register 0x%X\n",
296 				reg);
297 			return buf[i];
298 		}
299 		if (raw) {
300 			count++;
301 			continue;
302 		}
303 		switch (i) {
304 		case 10:
305 			buf[i] = twl4030battery_current(buf[i]);
306 			if (buf[i] < 0) {
307 				dev_err(madc->dev, "err reading current\n");
308 				return buf[i];
309 			} else {
310 				count++;
311 				buf[i] = buf[i] - 750;
312 			}
313 			break;
314 		case 1:
315 			buf[i] = twl4030battery_temperature(buf[i]);
316 			if (buf[i] < 0) {
317 				dev_err(madc->dev, "err reading temperature\n");
318 				return buf[i];
319 			} else {
320 				buf[i] -= 3;
321 				count++;
322 			}
323 			break;
324 		default:
325 			count++;
326 			/* Analog Input (V) = conv_result * step_size / R
327 			 * conv_result = decimal value of 10-bit conversion
328 			 *		 result
329 			 * step size = 1.5 / (2 ^ 10 -1)
330 			 * R = Prescaler ratio for input channels.
331 			 * Result given in mV hence multiplied by 1000.
332 			 */
333 			buf[i] = (buf[i] * 3 * 1000 *
334 				 twl4030_divider_ratios[i].denominator)
335 				/ (2 * 1023 *
336 				twl4030_divider_ratios[i].numerator);
337 		}
338 	}
339 
340 	return count;
341 }
342 
343 /*
344  * Enables irq.
345  * @madc - pointer to twl4030_madc_data struct
346  * @id - irq number to be enabled
347  * can take one of TWL4030_MADC_RT, TWL4030_MADC_SW1, TWL4030_MADC_SW2
348  * corresponding to RT, SW1, SW2 conversion requests.
349  * If the i2c read fails it returns an error else returns 0.
350  */
351 static int twl4030_madc_enable_irq(struct twl4030_madc_data *madc, u8 id)
352 {
353 	u8 val;
354 	int ret;
355 
356 	ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &val, madc->imr);
357 	if (ret) {
358 		dev_err(madc->dev, "unable to read imr register 0x%X\n",
359 			madc->imr);
360 		return ret;
361 	}
362 
363 	val &= ~(1 << id);
364 	ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, val, madc->imr);
365 	if (ret) {
366 		dev_err(madc->dev,
367 			"unable to write imr register 0x%X\n", madc->imr);
368 		return ret;
369 	}
370 
371 	return 0;
372 }
373 
374 /*
375  * Disables irq.
376  * @madc - pointer to twl4030_madc_data struct
377  * @id - irq number to be disabled
378  * can take one of TWL4030_MADC_RT, TWL4030_MADC_SW1, TWL4030_MADC_SW2
379  * corresponding to RT, SW1, SW2 conversion requests.
380  * Returns error if i2c read/write fails.
381  */
382 static int twl4030_madc_disable_irq(struct twl4030_madc_data *madc, u8 id)
383 {
384 	u8 val;
385 	int ret;
386 
387 	ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &val, madc->imr);
388 	if (ret) {
389 		dev_err(madc->dev, "unable to read imr register 0x%X\n",
390 			madc->imr);
391 		return ret;
392 	}
393 	val |= (1 << id);
394 	ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, val, madc->imr);
395 	if (ret) {
396 		dev_err(madc->dev,
397 			"unable to write imr register 0x%X\n", madc->imr);
398 		return ret;
399 	}
400 
401 	return 0;
402 }
403 
404 static irqreturn_t twl4030_madc_threaded_irq_handler(int irq, void *_madc)
405 {
406 	struct twl4030_madc_data *madc = _madc;
407 	const struct twl4030_madc_conversion_method *method;
408 	u8 isr_val, imr_val;
409 	int i, len, ret;
410 	struct twl4030_madc_request *r;
411 
412 	mutex_lock(&madc->lock);
413 	ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &isr_val, madc->isr);
414 	if (ret) {
415 		dev_err(madc->dev, "unable to read isr register 0x%X\n",
416 			madc->isr);
417 		goto err_i2c;
418 	}
419 	ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &imr_val, madc->imr);
420 	if (ret) {
421 		dev_err(madc->dev, "unable to read imr register 0x%X\n",
422 			madc->imr);
423 		goto err_i2c;
424 	}
425 	isr_val &= ~imr_val;
426 	for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
427 		if (!(isr_val & (1 << i)))
428 			continue;
429 		ret = twl4030_madc_disable_irq(madc, i);
430 		if (ret < 0)
431 			dev_dbg(madc->dev, "Disable interrupt failed %d\n", i);
432 		madc->requests[i].result_pending = 1;
433 	}
434 	for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
435 		r = &madc->requests[i];
436 		/* No pending results for this method, move to next one */
437 		if (!r->result_pending)
438 			continue;
439 		method = &twl4030_conversion_methods[r->method];
440 		/* Read results */
441 		len = twl4030_madc_read_channels(madc, method->rbase,
442 						 r->channels, r->rbuf, r->raw);
443 		/* Return results to caller */
444 		if (r->func_cb != NULL) {
445 			r->func_cb(len, r->channels, r->rbuf);
446 			r->func_cb = NULL;
447 		}
448 		/* Free request */
449 		r->result_pending = 0;
450 		r->active = 0;
451 	}
452 	mutex_unlock(&madc->lock);
453 
454 	return IRQ_HANDLED;
455 
456 err_i2c:
457 	/*
458 	 * In case of error check whichever request is active
459 	 * and service the same.
460 	 */
461 	for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
462 		r = &madc->requests[i];
463 		if (r->active == 0)
464 			continue;
465 		method = &twl4030_conversion_methods[r->method];
466 		/* Read results */
467 		len = twl4030_madc_read_channels(madc, method->rbase,
468 						 r->channels, r->rbuf, r->raw);
469 		/* Return results to caller */
470 		if (r->func_cb != NULL) {
471 			r->func_cb(len, r->channels, r->rbuf);
472 			r->func_cb = NULL;
473 		}
474 		/* Free request */
475 		r->result_pending = 0;
476 		r->active = 0;
477 	}
478 	mutex_unlock(&madc->lock);
479 
480 	return IRQ_HANDLED;
481 }
482 
483 static int twl4030_madc_set_irq(struct twl4030_madc_data *madc,
484 				struct twl4030_madc_request *req)
485 {
486 	struct twl4030_madc_request *p;
487 	int ret;
488 
489 	p = &madc->requests[req->method];
490 	memcpy(p, req, sizeof(*req));
491 	ret = twl4030_madc_enable_irq(madc, req->method);
492 	if (ret < 0) {
493 		dev_err(madc->dev, "enable irq failed!!\n");
494 		return ret;
495 	}
496 
497 	return 0;
498 }
499 
500 /*
501  * Function which enables the madc conversion
502  * by writing to the control register.
503  * @madc - pointer to twl4030_madc_data struct
504  * @conv_method - can be TWL4030_MADC_RT, TWL4030_MADC_SW2, TWL4030_MADC_SW1
505  * corresponding to RT SW1 or SW2 conversion methods.
506  * Returns 0 if succeeds else a negative error value
507  */
508 static int twl4030_madc_start_conversion(struct twl4030_madc_data *madc,
509 					 int conv_method)
510 {
511 	const struct twl4030_madc_conversion_method *method;
512 	int ret = 0;
513 
514 	if (conv_method != TWL4030_MADC_SW1 && conv_method != TWL4030_MADC_SW2)
515 		return -ENOTSUPP;
516 
517 	method = &twl4030_conversion_methods[conv_method];
518 	ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, TWL4030_MADC_SW_START,
519 			       method->ctrl);
520 	if (ret) {
521 		dev_err(madc->dev, "unable to write ctrl register 0x%X\n",
522 			method->ctrl);
523 		return ret;
524 	}
525 
526 	return 0;
527 }
528 
529 /*
530  * Function that waits for conversion to be ready
531  * @madc - pointer to twl4030_madc_data struct
532  * @timeout_ms - timeout value in milliseconds
533  * @status_reg - ctrl register
534  * returns 0 if succeeds else a negative error value
535  */
536 static int twl4030_madc_wait_conversion_ready(struct twl4030_madc_data *madc,
537 					      unsigned int timeout_ms,
538 					      u8 status_reg)
539 {
540 	unsigned long timeout;
541 	int ret;
542 
543 	timeout = jiffies + msecs_to_jiffies(timeout_ms);
544 	do {
545 		u8 reg;
546 
547 		ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &reg, status_reg);
548 		if (ret) {
549 			dev_err(madc->dev,
550 				"unable to read status register 0x%X\n",
551 				status_reg);
552 			return ret;
553 		}
554 		if (!(reg & TWL4030_MADC_BUSY) && (reg & TWL4030_MADC_EOC_SW))
555 			return 0;
556 		usleep_range(500, 2000);
557 	} while (!time_after(jiffies, timeout));
558 	dev_err(madc->dev, "conversion timeout!\n");
559 
560 	return -EAGAIN;
561 }
562 
563 /*
564  * An exported function which can be called from other kernel drivers.
565  * @req twl4030_madc_request structure
566  * req->rbuf will be filled with read values of channels based on the
567  * channel index. If a particular channel reading fails there will
568  * be a negative error value in the corresponding array element.
569  * returns 0 if succeeds else error value
570  */
571 int twl4030_madc_conversion(struct twl4030_madc_request *req)
572 {
573 	const struct twl4030_madc_conversion_method *method;
574 	int ret;
575 
576 	if (!req || !twl4030_madc)
577 		return -EINVAL;
578 
579 	mutex_lock(&twl4030_madc->lock);
580 	if (req->method < TWL4030_MADC_RT || req->method > TWL4030_MADC_SW2) {
581 		ret = -EINVAL;
582 		goto out;
583 	}
584 	/* Do we have a conversion request ongoing */
585 	if (twl4030_madc->requests[req->method].active) {
586 		ret = -EBUSY;
587 		goto out;
588 	}
589 	method = &twl4030_conversion_methods[req->method];
590 	/* Select channels to be converted */
591 	ret = twl_i2c_write_u16(TWL4030_MODULE_MADC, req->channels, method->sel);
592 	if (ret) {
593 		dev_err(twl4030_madc->dev,
594 			"unable to write sel register 0x%X\n", method->sel);
595 		goto out;
596 	}
597 	/* Select averaging for all channels if do_avg is set */
598 	if (req->do_avg) {
599 		ret = twl_i2c_write_u16(TWL4030_MODULE_MADC, req->channels,
600 				       method->avg);
601 		if (ret) {
602 			dev_err(twl4030_madc->dev,
603 				"unable to write avg register 0x%X\n",
604 				method->avg);
605 			goto out;
606 		}
607 	}
608 	if (req->type == TWL4030_MADC_IRQ_ONESHOT && req->func_cb != NULL) {
609 		ret = twl4030_madc_set_irq(twl4030_madc, req);
610 		if (ret < 0)
611 			goto out;
612 		ret = twl4030_madc_start_conversion(twl4030_madc, req->method);
613 		if (ret < 0)
614 			goto out;
615 		twl4030_madc->requests[req->method].active = 1;
616 		ret = 0;
617 		goto out;
618 	}
619 	/* With RT method we should not be here anymore */
620 	if (req->method == TWL4030_MADC_RT) {
621 		ret = -EINVAL;
622 		goto out;
623 	}
624 	ret = twl4030_madc_start_conversion(twl4030_madc, req->method);
625 	if (ret < 0)
626 		goto out;
627 	twl4030_madc->requests[req->method].active = 1;
628 	/* Wait until conversion is ready (ctrl register returns EOC) */
629 	ret = twl4030_madc_wait_conversion_ready(twl4030_madc, 5, method->ctrl);
630 	if (ret) {
631 		twl4030_madc->requests[req->method].active = 0;
632 		goto out;
633 	}
634 	ret = twl4030_madc_read_channels(twl4030_madc, method->rbase,
635 					 req->channels, req->rbuf, req->raw);
636 	twl4030_madc->requests[req->method].active = 0;
637 
638 out:
639 	mutex_unlock(&twl4030_madc->lock);
640 
641 	return ret;
642 }
643 EXPORT_SYMBOL_GPL(twl4030_madc_conversion);
644 
645 int twl4030_get_madc_conversion(int channel_no)
646 {
647 	struct twl4030_madc_request req;
648 	int temp = 0;
649 	int ret;
650 
651 	req.channels = (1 << channel_no);
652 	req.method = TWL4030_MADC_SW2;
653 	req.active = 0;
654 	req.raw = 0;
655 	req.func_cb = NULL;
656 	ret = twl4030_madc_conversion(&req);
657 	if (ret < 0)
658 		return ret;
659 	if (req.rbuf[channel_no] > 0)
660 		temp = req.rbuf[channel_no];
661 
662 	return temp;
663 }
664 EXPORT_SYMBOL_GPL(twl4030_get_madc_conversion);
665 
666 /**
667  * twl4030_madc_set_current_generator() - setup bias current
668  *
669  * @madc:	pointer to twl4030_madc_data struct
670  * @chan:	can be one of the two values:
671  *		0 - Enables bias current for main battery type reading
672  *		1 - Enables bias current for main battery temperature sensing
673  * @on:		enable or disable chan.
674  *
675  * Function to enable or disable bias current for
676  * main battery type reading or temperature sensing
677  */
678 static int twl4030_madc_set_current_generator(struct twl4030_madc_data *madc,
679 					      int chan, int on)
680 {
681 	int ret;
682 	int regmask;
683 	u8 regval;
684 
685 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
686 			      &regval, TWL4030_BCI_BCICTL1);
687 	if (ret) {
688 		dev_err(madc->dev, "unable to read BCICTL1 reg 0x%X",
689 			TWL4030_BCI_BCICTL1);
690 		return ret;
691 	}
692 
693 	regmask = chan ? TWL4030_BCI_ITHEN : TWL4030_BCI_TYPEN;
694 	if (on)
695 		regval |= regmask;
696 	else
697 		regval &= ~regmask;
698 
699 	ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
700 			       regval, TWL4030_BCI_BCICTL1);
701 	if (ret) {
702 		dev_err(madc->dev, "unable to write BCICTL1 reg 0x%X\n",
703 			TWL4030_BCI_BCICTL1);
704 		return ret;
705 	}
706 
707 	return 0;
708 }
709 
710 /*
711  * Function that sets MADC software power on bit to enable MADC
712  * @madc - pointer to twl4030_madc_data struct
713  * @on - Enable or disable MADC software power on bit.
714  * returns error if i2c read/write fails else 0
715  */
716 static int twl4030_madc_set_power(struct twl4030_madc_data *madc, int on)
717 {
718 	u8 regval;
719 	int ret;
720 
721 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
722 			      &regval, TWL4030_MADC_CTRL1);
723 	if (ret) {
724 		dev_err(madc->dev, "unable to read madc ctrl1 reg 0x%X\n",
725 			TWL4030_MADC_CTRL1);
726 		return ret;
727 	}
728 	if (on)
729 		regval |= TWL4030_MADC_MADCON;
730 	else
731 		regval &= ~TWL4030_MADC_MADCON;
732 	ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, regval, TWL4030_MADC_CTRL1);
733 	if (ret) {
734 		dev_err(madc->dev, "unable to write madc ctrl1 reg 0x%X\n",
735 			TWL4030_MADC_CTRL1);
736 		return ret;
737 	}
738 
739 	return 0;
740 }
741 
742 /*
743  * Initialize MADC and request for threaded irq
744  */
745 static int twl4030_madc_probe(struct platform_device *pdev)
746 {
747 	struct twl4030_madc_data *madc;
748 	struct twl4030_madc_platform_data *pdata = dev_get_platdata(&pdev->dev);
749 	struct device_node *np = pdev->dev.of_node;
750 	int irq, ret;
751 	u8 regval;
752 	struct iio_dev *iio_dev = NULL;
753 
754 	if (!pdata && !np) {
755 		dev_err(&pdev->dev, "neither platform data nor Device Tree node available\n");
756 		return -EINVAL;
757 	}
758 
759 	iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*madc));
760 	if (!iio_dev) {
761 		dev_err(&pdev->dev, "failed allocating iio device\n");
762 		return -ENOMEM;
763 	}
764 
765 	madc = iio_priv(iio_dev);
766 	madc->dev = &pdev->dev;
767 
768 	iio_dev->name = dev_name(&pdev->dev);
769 	iio_dev->dev.parent = &pdev->dev;
770 	iio_dev->dev.of_node = pdev->dev.of_node;
771 	iio_dev->info = &twl4030_madc_iio_info;
772 	iio_dev->modes = INDIO_DIRECT_MODE;
773 	iio_dev->channels = twl4030_madc_iio_channels;
774 	iio_dev->num_channels = ARRAY_SIZE(twl4030_madc_iio_channels);
775 
776 	/*
777 	 * Phoenix provides 2 interrupt lines. The first one is connected to
778 	 * the OMAP. The other one can be connected to the other processor such
779 	 * as modem. Hence two separate ISR and IMR registers.
780 	 */
781 	if (pdata)
782 		madc->use_second_irq = (pdata->irq_line != 1);
783 	else
784 		madc->use_second_irq = of_property_read_bool(np,
785 				       "ti,system-uses-second-madc-irq");
786 
787 	madc->imr = madc->use_second_irq ? TWL4030_MADC_IMR2 :
788 					   TWL4030_MADC_IMR1;
789 	madc->isr = madc->use_second_irq ? TWL4030_MADC_ISR2 :
790 					   TWL4030_MADC_ISR1;
791 
792 	ret = twl4030_madc_set_power(madc, 1);
793 	if (ret < 0)
794 		return ret;
795 	ret = twl4030_madc_set_current_generator(madc, 0, 1);
796 	if (ret < 0)
797 		goto err_current_generator;
798 
799 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
800 			      &regval, TWL4030_BCI_BCICTL1);
801 	if (ret) {
802 		dev_err(&pdev->dev, "unable to read reg BCI CTL1 0x%X\n",
803 			TWL4030_BCI_BCICTL1);
804 		goto err_i2c;
805 	}
806 	regval |= TWL4030_BCI_MESBAT;
807 	ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
808 			       regval, TWL4030_BCI_BCICTL1);
809 	if (ret) {
810 		dev_err(&pdev->dev, "unable to write reg BCI Ctl1 0x%X\n",
811 			TWL4030_BCI_BCICTL1);
812 		goto err_i2c;
813 	}
814 
815 	/* Check that MADC clock is on */
816 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &regval, TWL4030_REG_GPBR1);
817 	if (ret) {
818 		dev_err(&pdev->dev, "unable to read reg GPBR1 0x%X\n",
819 				TWL4030_REG_GPBR1);
820 		goto err_i2c;
821 	}
822 
823 	/* If MADC clk is not on, turn it on */
824 	if (!(regval & TWL4030_GPBR1_MADC_HFCLK_EN)) {
825 		dev_info(&pdev->dev, "clk disabled, enabling\n");
826 		regval |= TWL4030_GPBR1_MADC_HFCLK_EN;
827 		ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, regval,
828 				       TWL4030_REG_GPBR1);
829 		if (ret) {
830 			dev_err(&pdev->dev, "unable to write reg GPBR1 0x%X\n",
831 					TWL4030_REG_GPBR1);
832 			goto err_i2c;
833 		}
834 	}
835 
836 	platform_set_drvdata(pdev, iio_dev);
837 	mutex_init(&madc->lock);
838 
839 	irq = platform_get_irq(pdev, 0);
840 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
841 				   twl4030_madc_threaded_irq_handler,
842 				   IRQF_TRIGGER_RISING | IRQF_ONESHOT,
843 				   "twl4030_madc", madc);
844 	if (ret) {
845 		dev_err(&pdev->dev, "could not request irq\n");
846 		goto err_i2c;
847 	}
848 	twl4030_madc = madc;
849 
850 	/* Configure MADC[3:6] */
851 	ret = twl_i2c_read_u8(TWL_MODULE_USB, &regval,
852 			TWL4030_USB_CARKIT_ANA_CTRL);
853 	if (ret) {
854 		dev_err(&pdev->dev, "unable to read reg CARKIT_ANA_CTRL  0x%X\n",
855 				TWL4030_USB_CARKIT_ANA_CTRL);
856 		goto err_i2c;
857 	}
858 	regval |= TWL4030_USB_SEL_MADC_MCPC;
859 	ret = twl_i2c_write_u8(TWL_MODULE_USB, regval,
860 				 TWL4030_USB_CARKIT_ANA_CTRL);
861 	if (ret) {
862 		dev_err(&pdev->dev, "unable to write reg CARKIT_ANA_CTRL 0x%X\n",
863 				TWL4030_USB_CARKIT_ANA_CTRL);
864 		goto err_i2c;
865 	}
866 
867 	/* Enable 3v1 bias regulator for MADC[3:6] */
868 	madc->usb3v1 = devm_regulator_get(madc->dev, "vusb3v1");
869 	if (IS_ERR(madc->usb3v1))
870 		return -ENODEV;
871 
872 	ret = regulator_enable(madc->usb3v1);
873 	if (ret)
874 		dev_err(madc->dev, "could not enable 3v1 bias regulator\n");
875 
876 	ret = iio_device_register(iio_dev);
877 	if (ret) {
878 		dev_err(&pdev->dev, "could not register iio device\n");
879 		goto err_i2c;
880 	}
881 
882 	return 0;
883 
884 err_i2c:
885 	twl4030_madc_set_current_generator(madc, 0, 0);
886 err_current_generator:
887 	twl4030_madc_set_power(madc, 0);
888 	return ret;
889 }
890 
891 static int twl4030_madc_remove(struct platform_device *pdev)
892 {
893 	struct iio_dev *iio_dev = platform_get_drvdata(pdev);
894 	struct twl4030_madc_data *madc = iio_priv(iio_dev);
895 
896 	iio_device_unregister(iio_dev);
897 
898 	twl4030_madc_set_current_generator(madc, 0, 0);
899 	twl4030_madc_set_power(madc, 0);
900 
901 	regulator_disable(madc->usb3v1);
902 
903 	return 0;
904 }
905 
906 #ifdef CONFIG_OF
907 static const struct of_device_id twl_madc_of_match[] = {
908 	{ .compatible = "ti,twl4030-madc", },
909 	{ },
910 };
911 MODULE_DEVICE_TABLE(of, twl_madc_of_match);
912 #endif
913 
914 static struct platform_driver twl4030_madc_driver = {
915 	.probe = twl4030_madc_probe,
916 	.remove = twl4030_madc_remove,
917 	.driver = {
918 		   .name = "twl4030_madc",
919 		   .of_match_table = of_match_ptr(twl_madc_of_match),
920 	},
921 };
922 
923 module_platform_driver(twl4030_madc_driver);
924 
925 MODULE_DESCRIPTION("TWL4030 ADC driver");
926 MODULE_LICENSE("GPL");
927 MODULE_AUTHOR("J Keerthy");
928 MODULE_ALIAS("platform:twl4030_madc");
929