xref: /linux/drivers/iio/adc/twl4030-madc.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * TWL4030 MADC module driver-This driver monitors the real time
5  * conversion of analog signals like battery temperature,
6  * battery type, battery level etc.
7  *
8  * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
9  * J Keerthy <j-keerthy@ti.com>
10  *
11  * Based on twl4030-madc.c
12  * Copyright (C) 2008 Nokia Corporation
13  * Mikko Ylinen <mikko.k.ylinen@nokia.com>
14  *
15  * Amit Kucheria <amit.kucheria@canonical.com>
16  */
17 
18 #include <linux/device.h>
19 #include <linux/interrupt.h>
20 #include <linux/kernel.h>
21 #include <linux/delay.h>
22 #include <linux/mod_devicetable.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/property.h>
26 #include <linux/slab.h>
27 #include <linux/mfd/twl.h>
28 #include <linux/stddef.h>
29 #include <linux/mutex.h>
30 #include <linux/bitops.h>
31 #include <linux/jiffies.h>
32 #include <linux/types.h>
33 #include <linux/gfp.h>
34 #include <linux/err.h>
35 #include <linux/regulator/consumer.h>
36 
37 #include <linux/iio/iio.h>
38 
39 #define TWL4030_MADC_MAX_CHANNELS 16
40 
41 #define TWL4030_MADC_CTRL1		0x00
42 #define TWL4030_MADC_CTRL2		0x01
43 
44 #define TWL4030_MADC_RTSELECT_LSB	0x02
45 #define TWL4030_MADC_SW1SELECT_LSB	0x06
46 #define TWL4030_MADC_SW2SELECT_LSB	0x0A
47 
48 #define TWL4030_MADC_RTAVERAGE_LSB	0x04
49 #define TWL4030_MADC_SW1AVERAGE_LSB	0x08
50 #define TWL4030_MADC_SW2AVERAGE_LSB	0x0C
51 
52 #define TWL4030_MADC_CTRL_SW1		0x12
53 #define TWL4030_MADC_CTRL_SW2		0x13
54 
55 #define TWL4030_MADC_RTCH0_LSB		0x17
56 #define TWL4030_MADC_GPCH0_LSB		0x37
57 
58 #define TWL4030_MADC_MADCON	(1 << 0)	/* MADC power on */
59 #define TWL4030_MADC_BUSY	(1 << 0)	/* MADC busy */
60 /* MADC conversion completion */
61 #define TWL4030_MADC_EOC_SW	(1 << 1)
62 /* MADC SWx start conversion */
63 #define TWL4030_MADC_SW_START	(1 << 5)
64 #define TWL4030_MADC_ADCIN0	(1 << 0)
65 #define TWL4030_MADC_ADCIN1	(1 << 1)
66 #define TWL4030_MADC_ADCIN2	(1 << 2)
67 #define TWL4030_MADC_ADCIN3	(1 << 3)
68 #define TWL4030_MADC_ADCIN4	(1 << 4)
69 #define TWL4030_MADC_ADCIN5	(1 << 5)
70 #define TWL4030_MADC_ADCIN6	(1 << 6)
71 #define TWL4030_MADC_ADCIN7	(1 << 7)
72 #define TWL4030_MADC_ADCIN8	(1 << 8)
73 #define TWL4030_MADC_ADCIN9	(1 << 9)
74 #define TWL4030_MADC_ADCIN10	(1 << 10)
75 #define TWL4030_MADC_ADCIN11	(1 << 11)
76 #define TWL4030_MADC_ADCIN12	(1 << 12)
77 #define TWL4030_MADC_ADCIN13	(1 << 13)
78 #define TWL4030_MADC_ADCIN14	(1 << 14)
79 #define TWL4030_MADC_ADCIN15	(1 << 15)
80 
81 /* Fixed channels */
82 #define TWL4030_MADC_BTEMP	TWL4030_MADC_ADCIN1
83 #define TWL4030_MADC_VBUS	TWL4030_MADC_ADCIN8
84 #define TWL4030_MADC_VBKB	TWL4030_MADC_ADCIN9
85 #define TWL4030_MADC_ICHG	TWL4030_MADC_ADCIN10
86 #define TWL4030_MADC_VCHG	TWL4030_MADC_ADCIN11
87 #define TWL4030_MADC_VBAT	TWL4030_MADC_ADCIN12
88 
89 /* Step size and prescaler ratio */
90 #define TEMP_STEP_SIZE          147
91 #define TEMP_PSR_R              100
92 #define CURR_STEP_SIZE		147
93 #define CURR_PSR_R1		44
94 #define CURR_PSR_R2		88
95 
96 #define TWL4030_BCI_BCICTL1	0x23
97 #define TWL4030_BCI_CGAIN	0x020
98 #define TWL4030_BCI_MESBAT	(1 << 1)
99 #define TWL4030_BCI_TYPEN	(1 << 4)
100 #define TWL4030_BCI_ITHEN	(1 << 3)
101 
102 #define REG_BCICTL2             0x024
103 #define TWL4030_BCI_ITHSENS	0x007
104 
105 /* Register and bits for GPBR1 register */
106 #define TWL4030_REG_GPBR1		0x0c
107 #define TWL4030_GPBR1_MADC_HFCLK_EN	(1 << 7)
108 
109 #define TWL4030_USB_SEL_MADC_MCPC	(1<<3)
110 #define TWL4030_USB_CARKIT_ANA_CTRL	0xBB
111 
112 struct twl4030_madc_conversion_method {
113 	u8 sel;
114 	u8 avg;
115 	u8 rbase;
116 	u8 ctrl;
117 };
118 
119 /**
120  * struct twl4030_madc_request - madc request packet for channel conversion
121  * @channels:	16 bit bitmap for individual channels
122  * @do_avg:	sample the input channel for 4 consecutive cycles
123  * @method:	RT, SW1, SW2
124  * @type:	Polling or interrupt based method
125  * @active:	Flag if request is active
126  * @result_pending: Flag from irq handler, that result is ready
127  * @raw:	Return raw value, do not convert it
128  * @rbuf:	Result buffer
129  */
130 struct twl4030_madc_request {
131 	unsigned long channels;
132 	bool do_avg;
133 	u16 method;
134 	u16 type;
135 	bool active;
136 	bool result_pending;
137 	bool raw;
138 	int rbuf[TWL4030_MADC_MAX_CHANNELS];
139 };
140 
141 enum conversion_methods {
142 	TWL4030_MADC_RT,
143 	TWL4030_MADC_SW1,
144 	TWL4030_MADC_SW2,
145 	TWL4030_MADC_NUM_METHODS
146 };
147 
148 enum sample_type {
149 	TWL4030_MADC_WAIT,
150 	TWL4030_MADC_IRQ_ONESHOT,
151 	TWL4030_MADC_IRQ_REARM
152 };
153 
154 /**
155  * struct twl4030_madc_data - a container for madc info
156  * @dev:		Pointer to device structure for madc
157  * @lock:		Mutex protecting this data structure
158  * @usb3v1:		Pointer to bias regulator for madc
159  * @requests:		Array of request struct corresponding to SW1, SW2 and RT
160  * @use_second_irq:	IRQ selection (main or co-processor)
161  * @imr:		Interrupt mask register of MADC
162  * @isr:		Interrupt status register of MADC
163  */
164 struct twl4030_madc_data {
165 	struct device *dev;
166 	struct mutex lock;
167 	struct regulator *usb3v1;
168 	struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
169 	bool use_second_irq;
170 	u8 imr;
171 	u8 isr;
172 };
173 
174 static int twl4030_madc_conversion(struct twl4030_madc_request *req);
175 
176 static int twl4030_madc_read(struct iio_dev *iio_dev,
177 			     const struct iio_chan_spec *chan,
178 			     int *val, int *val2, long mask)
179 {
180 	struct twl4030_madc_data *madc = iio_priv(iio_dev);
181 	struct twl4030_madc_request req;
182 	int ret;
183 
184 	req.method = madc->use_second_irq ? TWL4030_MADC_SW2 : TWL4030_MADC_SW1;
185 
186 	req.channels = BIT(chan->channel);
187 	req.active = false;
188 	req.type = TWL4030_MADC_WAIT;
189 	req.raw = !(mask == IIO_CHAN_INFO_PROCESSED);
190 	req.do_avg = (mask == IIO_CHAN_INFO_AVERAGE_RAW);
191 
192 	ret = twl4030_madc_conversion(&req);
193 	if (ret < 0)
194 		return ret;
195 
196 	*val = req.rbuf[chan->channel];
197 
198 	return IIO_VAL_INT;
199 }
200 
201 static const struct iio_info twl4030_madc_iio_info = {
202 	.read_raw = &twl4030_madc_read,
203 };
204 
205 #define TWL4030_ADC_CHANNEL(_channel, _type, _name) {	\
206 	.type = _type,					\
207 	.channel = _channel,				\
208 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |  \
209 			      BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \
210 			      BIT(IIO_CHAN_INFO_PROCESSED), \
211 	.datasheet_name = _name,			\
212 	.indexed = 1,					\
213 }
214 
215 static const struct iio_chan_spec twl4030_madc_iio_channels[] = {
216 	TWL4030_ADC_CHANNEL(0, IIO_VOLTAGE, "ADCIN0"),
217 	TWL4030_ADC_CHANNEL(1, IIO_TEMP, "ADCIN1"),
218 	TWL4030_ADC_CHANNEL(2, IIO_VOLTAGE, "ADCIN2"),
219 	TWL4030_ADC_CHANNEL(3, IIO_VOLTAGE, "ADCIN3"),
220 	TWL4030_ADC_CHANNEL(4, IIO_VOLTAGE, "ADCIN4"),
221 	TWL4030_ADC_CHANNEL(5, IIO_VOLTAGE, "ADCIN5"),
222 	TWL4030_ADC_CHANNEL(6, IIO_VOLTAGE, "ADCIN6"),
223 	TWL4030_ADC_CHANNEL(7, IIO_VOLTAGE, "ADCIN7"),
224 	TWL4030_ADC_CHANNEL(8, IIO_VOLTAGE, "ADCIN8"),
225 	TWL4030_ADC_CHANNEL(9, IIO_VOLTAGE, "ADCIN9"),
226 	TWL4030_ADC_CHANNEL(10, IIO_CURRENT, "ADCIN10"),
227 	TWL4030_ADC_CHANNEL(11, IIO_VOLTAGE, "ADCIN11"),
228 	TWL4030_ADC_CHANNEL(12, IIO_VOLTAGE, "ADCIN12"),
229 	TWL4030_ADC_CHANNEL(13, IIO_VOLTAGE, "ADCIN13"),
230 	TWL4030_ADC_CHANNEL(14, IIO_VOLTAGE, "ADCIN14"),
231 	TWL4030_ADC_CHANNEL(15, IIO_VOLTAGE, "ADCIN15"),
232 };
233 
234 static struct twl4030_madc_data *twl4030_madc;
235 
236 static const struct s16_fract twl4030_divider_ratios[16] = {
237 	{1, 1},		/* CHANNEL 0 No Prescaler */
238 	{1, 1},		/* CHANNEL 1 No Prescaler */
239 	{6, 10},	/* CHANNEL 2 */
240 	{6, 10},	/* CHANNEL 3 */
241 	{6, 10},	/* CHANNEL 4 */
242 	{6, 10},	/* CHANNEL 5 */
243 	{6, 10},	/* CHANNEL 6 */
244 	{6, 10},	/* CHANNEL 7 */
245 	{3, 14},	/* CHANNEL 8 */
246 	{1, 3},		/* CHANNEL 9 */
247 	{1, 1},		/* CHANNEL 10 No Prescaler */
248 	{15, 100},	/* CHANNEL 11 */
249 	{1, 4},		/* CHANNEL 12 */
250 	{1, 1},		/* CHANNEL 13 Reserved channels */
251 	{1, 1},		/* CHANNEL 14 Reseved channels */
252 	{5, 11},	/* CHANNEL 15 */
253 };
254 
255 /* Conversion table from -3 to 55 degrees Celcius */
256 static int twl4030_therm_tbl[] = {
257 	30800,	29500,	28300,	27100,
258 	26000,	24900,	23900,	22900,	22000,	21100,	20300,	19400,	18700,
259 	17900,	17200,	16500,	15900,	15300,	14700,	14100,	13600,	13100,
260 	12600,	12100,	11600,	11200,	10800,	10400,	10000,	9630,	9280,
261 	8950,	8620,	8310,	8020,	7730,	7460,	7200,	6950,	6710,
262 	6470,	6250,	6040,	5830,	5640,	5450,	5260,	5090,	4920,
263 	4760,	4600,	4450,	4310,	4170,	4040,	3910,	3790,	3670,
264 	3550
265 };
266 
267 /*
268  * Structure containing the registers
269  * of different conversion methods supported by MADC.
270  * Hardware or RT real time conversion request initiated by external host
271  * processor for RT Signal conversions.
272  * External host processors can also request for non RT conversions
273  * SW1 and SW2 software conversions also called asynchronous or GPC request.
274  */
275 static
276 const struct twl4030_madc_conversion_method twl4030_conversion_methods[] = {
277 	[TWL4030_MADC_RT] = {
278 			     .sel = TWL4030_MADC_RTSELECT_LSB,
279 			     .avg = TWL4030_MADC_RTAVERAGE_LSB,
280 			     .rbase = TWL4030_MADC_RTCH0_LSB,
281 			     },
282 	[TWL4030_MADC_SW1] = {
283 			      .sel = TWL4030_MADC_SW1SELECT_LSB,
284 			      .avg = TWL4030_MADC_SW1AVERAGE_LSB,
285 			      .rbase = TWL4030_MADC_GPCH0_LSB,
286 			      .ctrl = TWL4030_MADC_CTRL_SW1,
287 			      },
288 	[TWL4030_MADC_SW2] = {
289 			      .sel = TWL4030_MADC_SW2SELECT_LSB,
290 			      .avg = TWL4030_MADC_SW2AVERAGE_LSB,
291 			      .rbase = TWL4030_MADC_GPCH0_LSB,
292 			      .ctrl = TWL4030_MADC_CTRL_SW2,
293 			      },
294 };
295 
296 /**
297  * twl4030_madc_channel_raw_read() - Function to read a particular channel value
298  * @madc:	pointer to struct twl4030_madc_data
299  * @reg:	lsb of ADC Channel
300  *
301  * Return: 0 on success, an error code otherwise.
302  */
303 static int twl4030_madc_channel_raw_read(struct twl4030_madc_data *madc, u8 reg)
304 {
305 	u16 val;
306 	int ret;
307 	/*
308 	 * For each ADC channel, we have MSB and LSB register pair. MSB address
309 	 * is always LSB address+1. reg parameter is the address of LSB register
310 	 */
311 	ret = twl_i2c_read_u16(TWL4030_MODULE_MADC, &val, reg);
312 	if (ret) {
313 		dev_err(madc->dev, "unable to read register 0x%X\n", reg);
314 		return ret;
315 	}
316 
317 	return (int)(val >> 6);
318 }
319 
320 /*
321  * Return battery temperature in degrees Celsius
322  * Or < 0 on failure.
323  */
324 static int twl4030battery_temperature(int raw_volt)
325 {
326 	u8 val;
327 	int temp, curr, volt, res, ret;
328 
329 	volt = (raw_volt * TEMP_STEP_SIZE) / TEMP_PSR_R;
330 	/* Getting and calculating the supply current in micro amperes */
331 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val,
332 		REG_BCICTL2);
333 	if (ret < 0)
334 		return ret;
335 
336 	curr = ((val & TWL4030_BCI_ITHSENS) + 1) * 10;
337 	/* Getting and calculating the thermistor resistance in ohms */
338 	res = volt * 1000 / curr;
339 	/* calculating temperature */
340 	for (temp = 58; temp >= 0; temp--) {
341 		int actual = twl4030_therm_tbl[temp];
342 		if ((actual - res) >= 0)
343 			break;
344 	}
345 
346 	return temp + 1;
347 }
348 
349 static int twl4030battery_current(int raw_volt)
350 {
351 	int ret;
352 	u8 val;
353 
354 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val,
355 		TWL4030_BCI_BCICTL1);
356 	if (ret)
357 		return ret;
358 	if (val & TWL4030_BCI_CGAIN) /* slope of 0.44 mV/mA */
359 		return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R1;
360 	else /* slope of 0.88 mV/mA */
361 		return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R2;
362 }
363 
364 /*
365  * Function to read channel values
366  * @madc - pointer to twl4030_madc_data struct
367  * @reg_base - Base address of the first channel
368  * @Channels - 16 bit bitmap. If the bit is set, channel's value is read
369  * @buf - The channel values are stored here. if read fails error
370  * @raw - Return raw values without conversion
371  * value is stored
372  * Returns the number of successfully read channels.
373  */
374 static int twl4030_madc_read_channels(struct twl4030_madc_data *madc,
375 				      u8 reg_base, unsigned
376 				      long channels, int *buf,
377 				      bool raw)
378 {
379 	int count = 0;
380 	int i;
381 	u8 reg;
382 
383 	for_each_set_bit(i, &channels, TWL4030_MADC_MAX_CHANNELS) {
384 		reg = reg_base + (2 * i);
385 		buf[i] = twl4030_madc_channel_raw_read(madc, reg);
386 		if (buf[i] < 0) {
387 			dev_err(madc->dev, "Unable to read register 0x%X\n",
388 				reg);
389 			return buf[i];
390 		}
391 		if (raw) {
392 			count++;
393 			continue;
394 		}
395 		switch (i) {
396 		case 10:
397 			buf[i] = twl4030battery_current(buf[i]);
398 			if (buf[i] < 0) {
399 				dev_err(madc->dev, "err reading current\n");
400 				return buf[i];
401 			} else {
402 				count++;
403 				buf[i] = buf[i] - 750;
404 			}
405 			break;
406 		case 1:
407 			buf[i] = twl4030battery_temperature(buf[i]);
408 			if (buf[i] < 0) {
409 				dev_err(madc->dev, "err reading temperature\n");
410 				return buf[i];
411 			} else {
412 				buf[i] -= 3;
413 				count++;
414 			}
415 			break;
416 		default:
417 			count++;
418 			/* Analog Input (V) = conv_result * step_size / R
419 			 * conv_result = decimal value of 10-bit conversion
420 			 *		 result
421 			 * step size = 1.5 / (2 ^ 10 -1)
422 			 * R = Prescaler ratio for input channels.
423 			 * Result given in mV hence multiplied by 1000.
424 			 */
425 			buf[i] = (buf[i] * 3 * 1000 *
426 				 twl4030_divider_ratios[i].denominator)
427 				/ (2 * 1023 *
428 				twl4030_divider_ratios[i].numerator);
429 		}
430 	}
431 
432 	return count;
433 }
434 
435 /*
436  * Disables irq.
437  * @madc - pointer to twl4030_madc_data struct
438  * @id - irq number to be disabled
439  * can take one of TWL4030_MADC_RT, TWL4030_MADC_SW1, TWL4030_MADC_SW2
440  * corresponding to RT, SW1, SW2 conversion requests.
441  * Returns error if i2c read/write fails.
442  */
443 static int twl4030_madc_disable_irq(struct twl4030_madc_data *madc, u8 id)
444 {
445 	u8 val;
446 	int ret;
447 
448 	ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &val, madc->imr);
449 	if (ret) {
450 		dev_err(madc->dev, "unable to read imr register 0x%X\n",
451 			madc->imr);
452 		return ret;
453 	}
454 	val |= (1 << id);
455 	ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, val, madc->imr);
456 	if (ret) {
457 		dev_err(madc->dev,
458 			"unable to write imr register 0x%X\n", madc->imr);
459 		return ret;
460 	}
461 
462 	return 0;
463 }
464 
465 static irqreturn_t twl4030_madc_threaded_irq_handler(int irq, void *_madc)
466 {
467 	struct twl4030_madc_data *madc = _madc;
468 	const struct twl4030_madc_conversion_method *method;
469 	u8 isr_val, imr_val;
470 	int i, ret;
471 	struct twl4030_madc_request *r;
472 
473 	mutex_lock(&madc->lock);
474 	ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &isr_val, madc->isr);
475 	if (ret) {
476 		dev_err(madc->dev, "unable to read isr register 0x%X\n",
477 			madc->isr);
478 		goto err_i2c;
479 	}
480 	ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &imr_val, madc->imr);
481 	if (ret) {
482 		dev_err(madc->dev, "unable to read imr register 0x%X\n",
483 			madc->imr);
484 		goto err_i2c;
485 	}
486 	isr_val &= ~imr_val;
487 	for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
488 		if (!(isr_val & (1 << i)))
489 			continue;
490 		ret = twl4030_madc_disable_irq(madc, i);
491 		if (ret < 0)
492 			dev_dbg(madc->dev, "Disable interrupt failed %d\n", i);
493 		madc->requests[i].result_pending = true;
494 	}
495 	for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
496 		r = &madc->requests[i];
497 		/* No pending results for this method, move to next one */
498 		if (!r->result_pending)
499 			continue;
500 		method = &twl4030_conversion_methods[r->method];
501 		/* Read results */
502 		twl4030_madc_read_channels(madc, method->rbase,
503 					   r->channels, r->rbuf, r->raw);
504 		/* Free request */
505 		r->result_pending = false;
506 		r->active = false;
507 	}
508 	mutex_unlock(&madc->lock);
509 
510 	return IRQ_HANDLED;
511 
512 err_i2c:
513 	/*
514 	 * In case of error check whichever request is active
515 	 * and service the same.
516 	 */
517 	for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
518 		r = &madc->requests[i];
519 		if (!r->active)
520 			continue;
521 		method = &twl4030_conversion_methods[r->method];
522 		/* Read results */
523 		twl4030_madc_read_channels(madc, method->rbase,
524 					   r->channels, r->rbuf, r->raw);
525 		/* Free request */
526 		r->result_pending = false;
527 		r->active = false;
528 	}
529 	mutex_unlock(&madc->lock);
530 
531 	return IRQ_HANDLED;
532 }
533 
534 /*
535  * Function which enables the madc conversion
536  * by writing to the control register.
537  * @madc - pointer to twl4030_madc_data struct
538  * @conv_method - can be TWL4030_MADC_RT, TWL4030_MADC_SW2, TWL4030_MADC_SW1
539  * corresponding to RT SW1 or SW2 conversion methods.
540  * Returns 0 if succeeds else a negative error value
541  */
542 static int twl4030_madc_start_conversion(struct twl4030_madc_data *madc,
543 					 int conv_method)
544 {
545 	const struct twl4030_madc_conversion_method *method;
546 	int ret = 0;
547 
548 	if (conv_method != TWL4030_MADC_SW1 && conv_method != TWL4030_MADC_SW2)
549 		return -ENOTSUPP;
550 
551 	method = &twl4030_conversion_methods[conv_method];
552 	ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, TWL4030_MADC_SW_START,
553 			       method->ctrl);
554 	if (ret) {
555 		dev_err(madc->dev, "unable to write ctrl register 0x%X\n",
556 			method->ctrl);
557 		return ret;
558 	}
559 
560 	return 0;
561 }
562 
563 /*
564  * Function that waits for conversion to be ready
565  * @madc - pointer to twl4030_madc_data struct
566  * @timeout_ms - timeout value in milliseconds
567  * @status_reg - ctrl register
568  * returns 0 if succeeds else a negative error value
569  */
570 static int twl4030_madc_wait_conversion_ready(struct twl4030_madc_data *madc,
571 					      unsigned int timeout_ms,
572 					      u8 status_reg)
573 {
574 	unsigned long timeout;
575 	int ret;
576 
577 	timeout = jiffies + msecs_to_jiffies(timeout_ms);
578 	do {
579 		u8 reg;
580 
581 		ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &reg, status_reg);
582 		if (ret) {
583 			dev_err(madc->dev,
584 				"unable to read status register 0x%X\n",
585 				status_reg);
586 			return ret;
587 		}
588 		if (!(reg & TWL4030_MADC_BUSY) && (reg & TWL4030_MADC_EOC_SW))
589 			return 0;
590 		usleep_range(500, 2000);
591 	} while (!time_after(jiffies, timeout));
592 	dev_err(madc->dev, "conversion timeout!\n");
593 
594 	return -EAGAIN;
595 }
596 
597 /*
598  * An exported function which can be called from other kernel drivers.
599  * @req twl4030_madc_request structure
600  * req->rbuf will be filled with read values of channels based on the
601  * channel index. If a particular channel reading fails there will
602  * be a negative error value in the corresponding array element.
603  * returns 0 if succeeds else error value
604  */
605 static int twl4030_madc_conversion(struct twl4030_madc_request *req)
606 {
607 	const struct twl4030_madc_conversion_method *method;
608 	int ret;
609 
610 	if (!req || !twl4030_madc)
611 		return -EINVAL;
612 
613 	mutex_lock(&twl4030_madc->lock);
614 	if (req->method < TWL4030_MADC_RT || req->method > TWL4030_MADC_SW2) {
615 		ret = -EINVAL;
616 		goto out;
617 	}
618 	/* Do we have a conversion request ongoing */
619 	if (twl4030_madc->requests[req->method].active) {
620 		ret = -EBUSY;
621 		goto out;
622 	}
623 	method = &twl4030_conversion_methods[req->method];
624 	/* Select channels to be converted */
625 	ret = twl_i2c_write_u16(TWL4030_MODULE_MADC, req->channels, method->sel);
626 	if (ret) {
627 		dev_err(twl4030_madc->dev,
628 			"unable to write sel register 0x%X\n", method->sel);
629 		goto out;
630 	}
631 	/* Select averaging for all channels if do_avg is set */
632 	if (req->do_avg) {
633 		ret = twl_i2c_write_u16(TWL4030_MODULE_MADC, req->channels,
634 				       method->avg);
635 		if (ret) {
636 			dev_err(twl4030_madc->dev,
637 				"unable to write avg register 0x%X\n",
638 				method->avg);
639 			goto out;
640 		}
641 	}
642 	/* With RT method we should not be here anymore */
643 	if (req->method == TWL4030_MADC_RT) {
644 		ret = -EINVAL;
645 		goto out;
646 	}
647 	ret = twl4030_madc_start_conversion(twl4030_madc, req->method);
648 	if (ret < 0)
649 		goto out;
650 	twl4030_madc->requests[req->method].active = true;
651 	/* Wait until conversion is ready (ctrl register returns EOC) */
652 	ret = twl4030_madc_wait_conversion_ready(twl4030_madc, 5, method->ctrl);
653 	if (ret) {
654 		twl4030_madc->requests[req->method].active = false;
655 		goto out;
656 	}
657 	ret = twl4030_madc_read_channels(twl4030_madc, method->rbase,
658 					 req->channels, req->rbuf, req->raw);
659 	twl4030_madc->requests[req->method].active = false;
660 
661 out:
662 	mutex_unlock(&twl4030_madc->lock);
663 
664 	return ret;
665 }
666 
667 /**
668  * twl4030_madc_set_current_generator() - setup bias current
669  *
670  * @madc:	pointer to twl4030_madc_data struct
671  * @chan:	can be one of the two values:
672  *		0 - Enables bias current for main battery type reading
673  *		1 - Enables bias current for main battery temperature sensing
674  * @on:		enable or disable chan.
675  *
676  * Function to enable or disable bias current for
677  * main battery type reading or temperature sensing
678  */
679 static int twl4030_madc_set_current_generator(struct twl4030_madc_data *madc,
680 					      int chan, int on)
681 {
682 	int ret;
683 	int regmask;
684 	u8 regval;
685 
686 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
687 			      &regval, TWL4030_BCI_BCICTL1);
688 	if (ret) {
689 		dev_err(madc->dev, "unable to read BCICTL1 reg 0x%X",
690 			TWL4030_BCI_BCICTL1);
691 		return ret;
692 	}
693 
694 	regmask = chan ? TWL4030_BCI_ITHEN : TWL4030_BCI_TYPEN;
695 	if (on)
696 		regval |= regmask;
697 	else
698 		regval &= ~regmask;
699 
700 	ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
701 			       regval, TWL4030_BCI_BCICTL1);
702 	if (ret) {
703 		dev_err(madc->dev, "unable to write BCICTL1 reg 0x%X\n",
704 			TWL4030_BCI_BCICTL1);
705 		return ret;
706 	}
707 
708 	return 0;
709 }
710 
711 /*
712  * Function that sets MADC software power on bit to enable MADC
713  * @madc - pointer to twl4030_madc_data struct
714  * @on - Enable or disable MADC software power on bit.
715  * returns error if i2c read/write fails else 0
716  */
717 static int twl4030_madc_set_power(struct twl4030_madc_data *madc, int on)
718 {
719 	u8 regval;
720 	int ret;
721 
722 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
723 			      &regval, TWL4030_MADC_CTRL1);
724 	if (ret) {
725 		dev_err(madc->dev, "unable to read madc ctrl1 reg 0x%X\n",
726 			TWL4030_MADC_CTRL1);
727 		return ret;
728 	}
729 	if (on)
730 		regval |= TWL4030_MADC_MADCON;
731 	else
732 		regval &= ~TWL4030_MADC_MADCON;
733 	ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, regval, TWL4030_MADC_CTRL1);
734 	if (ret) {
735 		dev_err(madc->dev, "unable to write madc ctrl1 reg 0x%X\n",
736 			TWL4030_MADC_CTRL1);
737 		return ret;
738 	}
739 
740 	return 0;
741 }
742 
743 /*
744  * Initialize MADC and request for threaded irq
745  */
746 static int twl4030_madc_probe(struct platform_device *pdev)
747 {
748 	struct device *dev = &pdev->dev;
749 	struct twl4030_madc_platform_data *pdata = dev_get_platdata(dev);
750 	struct twl4030_madc_data *madc;
751 	int irq, ret;
752 	u8 regval;
753 	struct iio_dev *iio_dev = NULL;
754 
755 	if (!pdata && !dev_fwnode(dev)) {
756 		dev_err(&pdev->dev, "neither platform data nor Device Tree node available\n");
757 		return -EINVAL;
758 	}
759 
760 	iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*madc));
761 	if (!iio_dev) {
762 		dev_err(&pdev->dev, "failed allocating iio device\n");
763 		return -ENOMEM;
764 	}
765 
766 	madc = iio_priv(iio_dev);
767 	madc->dev = &pdev->dev;
768 
769 	iio_dev->name = dev_name(&pdev->dev);
770 	iio_dev->info = &twl4030_madc_iio_info;
771 	iio_dev->modes = INDIO_DIRECT_MODE;
772 	iio_dev->channels = twl4030_madc_iio_channels;
773 	iio_dev->num_channels = ARRAY_SIZE(twl4030_madc_iio_channels);
774 
775 	/*
776 	 * Phoenix provides 2 interrupt lines. The first one is connected to
777 	 * the OMAP. The other one can be connected to the other processor such
778 	 * as modem. Hence two separate ISR and IMR registers.
779 	 */
780 	if (pdata)
781 		madc->use_second_irq = (pdata->irq_line != 1);
782 	else
783 		madc->use_second_irq = device_property_read_bool(dev,
784 				       "ti,system-uses-second-madc-irq");
785 
786 	madc->imr = madc->use_second_irq ? TWL4030_MADC_IMR2 :
787 					   TWL4030_MADC_IMR1;
788 	madc->isr = madc->use_second_irq ? TWL4030_MADC_ISR2 :
789 					   TWL4030_MADC_ISR1;
790 
791 	ret = twl4030_madc_set_power(madc, 1);
792 	if (ret < 0)
793 		return ret;
794 	ret = twl4030_madc_set_current_generator(madc, 0, 1);
795 	if (ret < 0)
796 		goto err_current_generator;
797 
798 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE,
799 			      &regval, TWL4030_BCI_BCICTL1);
800 	if (ret) {
801 		dev_err(&pdev->dev, "unable to read reg BCI CTL1 0x%X\n",
802 			TWL4030_BCI_BCICTL1);
803 		goto err_i2c;
804 	}
805 	regval |= TWL4030_BCI_MESBAT;
806 	ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
807 			       regval, TWL4030_BCI_BCICTL1);
808 	if (ret) {
809 		dev_err(&pdev->dev, "unable to write reg BCI Ctl1 0x%X\n",
810 			TWL4030_BCI_BCICTL1);
811 		goto err_i2c;
812 	}
813 
814 	/* Check that MADC clock is on */
815 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &regval, TWL4030_REG_GPBR1);
816 	if (ret) {
817 		dev_err(&pdev->dev, "unable to read reg GPBR1 0x%X\n",
818 				TWL4030_REG_GPBR1);
819 		goto err_i2c;
820 	}
821 
822 	/* If MADC clk is not on, turn it on */
823 	if (!(regval & TWL4030_GPBR1_MADC_HFCLK_EN)) {
824 		dev_info(&pdev->dev, "clk disabled, enabling\n");
825 		regval |= TWL4030_GPBR1_MADC_HFCLK_EN;
826 		ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, regval,
827 				       TWL4030_REG_GPBR1);
828 		if (ret) {
829 			dev_err(&pdev->dev, "unable to write reg GPBR1 0x%X\n",
830 					TWL4030_REG_GPBR1);
831 			goto err_i2c;
832 		}
833 	}
834 
835 	platform_set_drvdata(pdev, iio_dev);
836 	mutex_init(&madc->lock);
837 
838 	irq = platform_get_irq(pdev, 0);
839 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
840 				   twl4030_madc_threaded_irq_handler,
841 				   IRQF_TRIGGER_RISING | IRQF_ONESHOT,
842 				   "twl4030_madc", madc);
843 	if (ret) {
844 		dev_err(&pdev->dev, "could not request irq\n");
845 		goto err_i2c;
846 	}
847 	twl4030_madc = madc;
848 
849 	/* Configure MADC[3:6] */
850 	ret = twl_i2c_read_u8(TWL_MODULE_USB, &regval,
851 			TWL4030_USB_CARKIT_ANA_CTRL);
852 	if (ret) {
853 		dev_err(&pdev->dev, "unable to read reg CARKIT_ANA_CTRL  0x%X\n",
854 				TWL4030_USB_CARKIT_ANA_CTRL);
855 		goto err_i2c;
856 	}
857 	regval |= TWL4030_USB_SEL_MADC_MCPC;
858 	ret = twl_i2c_write_u8(TWL_MODULE_USB, regval,
859 				 TWL4030_USB_CARKIT_ANA_CTRL);
860 	if (ret) {
861 		dev_err(&pdev->dev, "unable to write reg CARKIT_ANA_CTRL 0x%X\n",
862 				TWL4030_USB_CARKIT_ANA_CTRL);
863 		goto err_i2c;
864 	}
865 
866 	/* Enable 3v1 bias regulator for MADC[3:6] */
867 	madc->usb3v1 = devm_regulator_get(madc->dev, "vusb3v1");
868 	if (IS_ERR(madc->usb3v1)) {
869 		ret = -ENODEV;
870 		goto err_i2c;
871 	}
872 
873 	ret = regulator_enable(madc->usb3v1);
874 	if (ret) {
875 		dev_err(madc->dev, "could not enable 3v1 bias regulator\n");
876 		goto err_i2c;
877 	}
878 
879 	ret = iio_device_register(iio_dev);
880 	if (ret) {
881 		dev_err(&pdev->dev, "could not register iio device\n");
882 		goto err_usb3v1;
883 	}
884 
885 	return 0;
886 
887 err_usb3v1:
888 	regulator_disable(madc->usb3v1);
889 err_i2c:
890 	twl4030_madc_set_current_generator(madc, 0, 0);
891 err_current_generator:
892 	twl4030_madc_set_power(madc, 0);
893 	return ret;
894 }
895 
896 static void twl4030_madc_remove(struct platform_device *pdev)
897 {
898 	struct iio_dev *iio_dev = platform_get_drvdata(pdev);
899 	struct twl4030_madc_data *madc = iio_priv(iio_dev);
900 
901 	iio_device_unregister(iio_dev);
902 
903 	twl4030_madc_set_current_generator(madc, 0, 0);
904 	twl4030_madc_set_power(madc, 0);
905 
906 	regulator_disable(madc->usb3v1);
907 }
908 
909 static const struct of_device_id twl_madc_of_match[] = {
910 	{ .compatible = "ti,twl4030-madc", },
911 	{ }
912 };
913 MODULE_DEVICE_TABLE(of, twl_madc_of_match);
914 
915 static struct platform_driver twl4030_madc_driver = {
916 	.probe = twl4030_madc_probe,
917 	.remove_new = twl4030_madc_remove,
918 	.driver = {
919 		   .name = "twl4030_madc",
920 		   .of_match_table = twl_madc_of_match,
921 	},
922 };
923 
924 module_platform_driver(twl4030_madc_driver);
925 
926 MODULE_DESCRIPTION("TWL4030 ADC driver");
927 MODULE_LICENSE("GPL");
928 MODULE_AUTHOR("J Keerthy");
929 MODULE_ALIAS("platform:twl4030_madc");
930