xref: /openbmc/linux/drivers/iio/adc/cpcap-adc.c (revision d236d361)
1 /*
2  * Copyright (C) 2017 Tony Lindgren <tony@atomide.com>
3  *
4  * Rewritten for Linux IIO framework with some code based on
5  * earlier driver found in the Motorola Linux kernel:
6  *
7  * Copyright (C) 2009-2010 Motorola, Inc.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16  * GNU General Public License for more details.
17  */
18 
19 #include <linux/delay.h>
20 #include <linux/device.h>
21 #include <linux/err.h>
22 #include <linux/init.h>
23 #include <linux/interrupt.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/of.h>
27 #include <linux/of_platform.h>
28 #include <linux/platform_device.h>
29 #include <linux/regmap.h>
30 
31 #include <linux/iio/buffer.h>
32 #include <linux/iio/driver.h>
33 #include <linux/iio/iio.h>
34 #include <linux/iio/kfifo_buf.h>
35 #include <linux/mfd/motorola-cpcap.h>
36 
37 /* Register CPCAP_REG_ADCC1 bits */
38 #define CPCAP_BIT_ADEN_AUTO_CLR		BIT(15)	/* Currently unused */
39 #define CPCAP_BIT_CAL_MODE		BIT(14) /* Set with BIT_RAND0 */
40 #define CPCAP_BIT_ADC_CLK_SEL1		BIT(13)	/* Currently unused */
41 #define CPCAP_BIT_ADC_CLK_SEL0		BIT(12)	/* Currently unused */
42 #define CPCAP_BIT_ATOX			BIT(11)
43 #define CPCAP_BIT_ATO3			BIT(10)
44 #define CPCAP_BIT_ATO2			BIT(9)
45 #define CPCAP_BIT_ATO1			BIT(8)
46 #define CPCAP_BIT_ATO0			BIT(7)
47 #define CPCAP_BIT_ADA2			BIT(6)
48 #define CPCAP_BIT_ADA1			BIT(5)
49 #define CPCAP_BIT_ADA0			BIT(4)
50 #define CPCAP_BIT_AD_SEL1		BIT(3)	/* Set for bank1 */
51 #define CPCAP_BIT_RAND1			BIT(2)	/* Set for channel 16 & 17 */
52 #define CPCAP_BIT_RAND0			BIT(1)	/* Set with CAL_MODE */
53 #define CPCAP_BIT_ADEN			BIT(0)	/* Currently unused */
54 
55 /* Register CPCAP_REG_ADCC2 bits */
56 #define CPCAP_BIT_CAL_FACTOR_ENABLE	BIT(15)	/* Currently unused */
57 #define CPCAP_BIT_BATDETB_EN		BIT(14)	/* Currently unused */
58 #define CPCAP_BIT_ADTRIG_ONESHOT	BIT(13)	/* Set for !TIMING_IMM */
59 #define CPCAP_BIT_ASC			BIT(12)	/* Set for TIMING_IMM */
60 #define CPCAP_BIT_ATOX_PS_FACTOR	BIT(11)
61 #define CPCAP_BIT_ADC_PS_FACTOR1	BIT(10)
62 #define CPCAP_BIT_ADC_PS_FACTOR0	BIT(9)
63 #define CPCAP_BIT_AD4_SELECT		BIT(8)	/* Currently unused */
64 #define CPCAP_BIT_ADC_BUSY		BIT(7)	/* Currently unused */
65 #define CPCAP_BIT_THERMBIAS_EN		BIT(6)	/* Currently unused */
66 #define CPCAP_BIT_ADTRIG_DIS		BIT(5)	/* Disable interrupt */
67 #define CPCAP_BIT_LIADC			BIT(4)	/* Currently unused */
68 #define CPCAP_BIT_TS_REFEN		BIT(3)	/* Currently unused */
69 #define CPCAP_BIT_TS_M2			BIT(2)	/* Currently unused */
70 #define CPCAP_BIT_TS_M1			BIT(1)	/* Currently unused */
71 #define CPCAP_BIT_TS_M0			BIT(0)	/* Currently unused */
72 
73 #define CPCAP_MAX_TEMP_LVL		27
74 #define CPCAP_FOUR_POINT_TWO_ADC	801
75 #define ST_ADC_CAL_CHRGI_HIGH_THRESHOLD	530
76 #define ST_ADC_CAL_CHRGI_LOW_THRESHOLD	494
77 #define ST_ADC_CAL_BATTI_HIGH_THRESHOLD	530
78 #define ST_ADC_CAL_BATTI_LOW_THRESHOLD	494
79 #define ST_ADC_CALIBRATE_DIFF_THRESHOLD	3
80 
81 #define CPCAP_ADC_MAX_RETRIES		5	/* Calibration and quirk */
82 
83 /**
84  * struct cpcap_adc_ato - timing settings for cpcap adc
85  *
86  * Unfortunately no cpcap documentation available, please document when
87  * using these.
88  */
89 struct cpcap_adc_ato {
90 	unsigned short ato_in;
91 	unsigned short atox_in;
92 	unsigned short adc_ps_factor_in;
93 	unsigned short atox_ps_factor_in;
94 	unsigned short ato_out;
95 	unsigned short atox_out;
96 	unsigned short adc_ps_factor_out;
97 	unsigned short atox_ps_factor_out;
98 };
99 
100 /**
101  * struct cpcap-adc - cpcap adc device driver data
102  * @reg: cpcap regmap
103  * @dev: struct device
104  * @vendor: cpcap vendor
105  * @irq: interrupt
106  * @lock: mutex
107  * @ato: request timings
108  * @wq_data_avail: work queue
109  * @done: work done
110  */
111 struct cpcap_adc {
112 	struct regmap *reg;
113 	struct device *dev;
114 	u16 vendor;
115 	int irq;
116 	struct mutex lock;	/* ADC register access lock */
117 	const struct cpcap_adc_ato *ato;
118 	wait_queue_head_t wq_data_avail;
119 	bool done;
120 };
121 
122 /**
123  * enum cpcap_adc_channel - cpcap adc channels
124  */
125 enum cpcap_adc_channel {
126 	/* Bank0 channels */
127 	CPCAP_ADC_AD0_BATTDETB,	/* Battery detection */
128 	CPCAP_ADC_BATTP,	/* Battery voltage */
129 	CPCAP_ADC_VBUS,		/* USB VBUS voltage */
130 	CPCAP_ADC_AD3,		/* Battery temperature when charging */
131 	CPCAP_ADC_BPLUS_AD4,	/* Another battery or system voltage */
132 	CPCAP_ADC_CHG_ISENSE,	/* Calibrated charge current */
133 	CPCAP_ADC_BATTI,	/* Calibrated system current */
134 	CPCAP_ADC_USB_ID,	/* USB OTG ID, unused on droid 4? */
135 
136 	/* Bank1 channels */
137 	CPCAP_ADC_AD8,		/* Seems unused */
138 	CPCAP_ADC_AD9,		/* Seems unused */
139 	CPCAP_ADC_LICELL,	/* Maybe system voltage? Always 3V */
140 	CPCAP_ADC_HV_BATTP,	/* Another battery detection? */
141 	CPCAP_ADC_TSX1_AD12,	/* Seems unused, for touchscreen? */
142 	CPCAP_ADC_TSX2_AD13,	/* Seems unused, for touchscreen? */
143 	CPCAP_ADC_TSY1_AD14,	/* Seems unused, for touchscreen? */
144 	CPCAP_ADC_TSY2_AD15,	/* Seems unused, for touchscreen? */
145 
146 	/* Remuxed channels using bank0 entries */
147 	CPCAP_ADC_BATTP_PI16,	/* Alternative mux mode for BATTP */
148 	CPCAP_ADC_BATTI_PI17,	/* Alternative mux mode for BATTI */
149 
150 	CPCAP_ADC_CHANNEL_NUM,
151 };
152 
153 /**
154  * enum cpcap_adc_timing - cpcap adc timing options
155  *
156  * CPCAP_ADC_TIMING_IMM seems to be immediate with no timings.
157  * Please document when using.
158  */
159 enum cpcap_adc_timing {
160 	CPCAP_ADC_TIMING_IMM,
161 	CPCAP_ADC_TIMING_IN,
162 	CPCAP_ADC_TIMING_OUT,
163 };
164 
165 /**
166  * struct cpcap_adc_phasing_tbl - cpcap phasing table
167  * @offset: offset in the phasing table
168  * @multiplier: multiplier in the phasing table
169  * @divider: divider in the phasing table
170  * @min: minimum value
171  * @max: maximum value
172  */
173 struct cpcap_adc_phasing_tbl {
174 	short offset;
175 	unsigned short multiplier;
176 	unsigned short divider;
177 	short min;
178 	short max;
179 };
180 
181 /**
182  * struct cpcap_adc_conversion_tbl - cpcap conversion table
183  * @conv_type: conversion type
184  * @align_offset: align offset
185  * @conv_offset: conversion offset
186  * @cal_offset: calibration offset
187  * @multiplier: conversion multiplier
188  * @divider: conversion divider
189  */
190 struct cpcap_adc_conversion_tbl {
191 	enum iio_chan_info_enum conv_type;
192 	int align_offset;
193 	int conv_offset;
194 	int cal_offset;
195 	int multiplier;
196 	int divider;
197 };
198 
199 /**
200  * struct cpcap_adc_request - cpcap adc request
201  * @channel: request channel
202  * @phase_tbl: channel phasing table
203  * @conv_tbl: channel conversion table
204  * @bank_index: channel index within the bank
205  * @timing: timing settings
206  * @result: result
207  */
208 struct cpcap_adc_request {
209 	int channel;
210 	const struct cpcap_adc_phasing_tbl *phase_tbl;
211 	const struct cpcap_adc_conversion_tbl *conv_tbl;
212 	int bank_index;
213 	enum cpcap_adc_timing timing;
214 	int result;
215 };
216 
217 /* Phasing table for channels. Note that channels 16 & 17 use BATTP and BATTI */
218 static const struct cpcap_adc_phasing_tbl bank_phasing[] = {
219 	/* Bank0 */
220 	[CPCAP_ADC_AD0_BATTDETB] = {0, 0x80, 0x80,    0, 1023},
221 	[CPCAP_ADC_BATTP] =        {0, 0x80, 0x80,    0, 1023},
222 	[CPCAP_ADC_VBUS] =         {0, 0x80, 0x80,    0, 1023},
223 	[CPCAP_ADC_AD3] =          {0, 0x80, 0x80,    0, 1023},
224 	[CPCAP_ADC_BPLUS_AD4] =    {0, 0x80, 0x80,    0, 1023},
225 	[CPCAP_ADC_CHG_ISENSE] =   {0, 0x80, 0x80, -512,  511},
226 	[CPCAP_ADC_BATTI] =        {0, 0x80, 0x80, -512,  511},
227 	[CPCAP_ADC_USB_ID] =       {0, 0x80, 0x80,    0, 1023},
228 
229 	/* Bank1 */
230 	[CPCAP_ADC_AD8] =          {0, 0x80, 0x80,    0, 1023},
231 	[CPCAP_ADC_AD9] =          {0, 0x80, 0x80,    0, 1023},
232 	[CPCAP_ADC_LICELL] =       {0, 0x80, 0x80,    0, 1023},
233 	[CPCAP_ADC_HV_BATTP] =     {0, 0x80, 0x80,    0, 1023},
234 	[CPCAP_ADC_TSX1_AD12] =    {0, 0x80, 0x80,    0, 1023},
235 	[CPCAP_ADC_TSX2_AD13] =    {0, 0x80, 0x80,    0, 1023},
236 	[CPCAP_ADC_TSY1_AD14] =    {0, 0x80, 0x80,    0, 1023},
237 	[CPCAP_ADC_TSY2_AD15] =    {0, 0x80, 0x80,    0, 1023},
238 };
239 
240 /*
241  * Conversion table for channels. Updated during init based on calibration.
242  * Here too channels 16 & 17 use BATTP and BATTI.
243  */
244 static struct cpcap_adc_conversion_tbl bank_conversion[] = {
245 	/* Bank0 */
246 	[CPCAP_ADC_AD0_BATTDETB] = {
247 		IIO_CHAN_INFO_PROCESSED,    0,    0, 0,     1,    1,
248 	},
249 	[CPCAP_ADC_BATTP] = {
250 		IIO_CHAN_INFO_PROCESSED,    0, 2400, 0,  2300, 1023,
251 	},
252 	[CPCAP_ADC_VBUS] = {
253 		IIO_CHAN_INFO_PROCESSED,    0,    0, 0, 10000, 1023,
254 	},
255 	[CPCAP_ADC_AD3] = {
256 		IIO_CHAN_INFO_PROCESSED,    0,    0, 0,     1,    1,
257 		},
258 	[CPCAP_ADC_BPLUS_AD4] = {
259 		IIO_CHAN_INFO_PROCESSED,    0, 2400, 0,  2300, 1023,
260 	},
261 	[CPCAP_ADC_CHG_ISENSE] = {
262 		IIO_CHAN_INFO_PROCESSED, -512,    2, 0,  5000, 1023,
263 	},
264 	[CPCAP_ADC_BATTI] = {
265 		IIO_CHAN_INFO_PROCESSED, -512,    2, 0,  5000, 1023,
266 	},
267 	[CPCAP_ADC_USB_ID] = {
268 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
269 	},
270 
271 	/* Bank1 */
272 	[CPCAP_ADC_AD8] = {
273 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
274 	},
275 	[CPCAP_ADC_AD9] = {
276 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
277 	},
278 	[CPCAP_ADC_LICELL] = {
279 		IIO_CHAN_INFO_PROCESSED,    0,    0, 0,  3400, 1023,
280 	},
281 	[CPCAP_ADC_HV_BATTP] = {
282 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
283 	},
284 	[CPCAP_ADC_TSX1_AD12] = {
285 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
286 	},
287 	[CPCAP_ADC_TSX2_AD13] = {
288 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
289 	},
290 	[CPCAP_ADC_TSY1_AD14] = {
291 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
292 	},
293 	[CPCAP_ADC_TSY2_AD15] = {
294 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
295 	},
296 };
297 
298 /*
299  * Temperature lookup table of register values to milliCelcius.
300  * REVISIT: Check the duplicate 0x3ff entry in a freezer
301  */
302 static const int temp_map[CPCAP_MAX_TEMP_LVL][2] = {
303 	{ 0x03ff, -40000 },
304 	{ 0x03ff, -35000 },
305 	{ 0x03ef, -30000 },
306 	{ 0x03b2, -25000 },
307 	{ 0x036c, -20000 },
308 	{ 0x0320, -15000 },
309 	{ 0x02d0, -10000 },
310 	{ 0x027f, -5000 },
311 	{ 0x022f, 0 },
312 	{ 0x01e4, 5000 },
313 	{ 0x019f, 10000 },
314 	{ 0x0161, 15000 },
315 	{ 0x012b, 20000 },
316 	{ 0x00fc, 25000 },
317 	{ 0x00d4, 30000 },
318 	{ 0x00b2, 35000 },
319 	{ 0x0095, 40000 },
320 	{ 0x007d, 45000 },
321 	{ 0x0069, 50000 },
322 	{ 0x0059, 55000 },
323 	{ 0x004b, 60000 },
324 	{ 0x003f, 65000 },
325 	{ 0x0036, 70000 },
326 	{ 0x002e, 75000 },
327 	{ 0x0027, 80000 },
328 	{ 0x0022, 85000 },
329 	{ 0x001d, 90000 },
330 };
331 
332 #define CPCAP_CHAN(_type, _index, _address, _datasheet_name) {	\
333 	.type = (_type), \
334 	.address = (_address), \
335 	.indexed = 1, \
336 	.channel = (_index), \
337 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
338 			      BIT(IIO_CHAN_INFO_PROCESSED), \
339 	.scan_index = (_index), \
340 	.scan_type = { \
341 		.sign = 'u', \
342 		.realbits = 10, \
343 		.storagebits = 16, \
344 		.endianness = IIO_CPU, \
345 	}, \
346 	.datasheet_name = (_datasheet_name), \
347 }
348 
349 /*
350  * The datasheet names are from Motorola mapphone Linux kernel except
351  * for the last two which might be uncalibrated charge voltage and
352  * current.
353  */
354 static const struct iio_chan_spec cpcap_adc_channels[] = {
355 	/* Bank0 */
356 	CPCAP_CHAN(IIO_TEMP,    0, CPCAP_REG_ADCD0,  "battdetb"),
357 	CPCAP_CHAN(IIO_VOLTAGE, 1, CPCAP_REG_ADCD1,  "battp"),
358 	CPCAP_CHAN(IIO_VOLTAGE, 2, CPCAP_REG_ADCD2,  "vbus"),
359 	CPCAP_CHAN(IIO_TEMP,    3, CPCAP_REG_ADCD3,  "ad3"),
360 	CPCAP_CHAN(IIO_VOLTAGE, 4, CPCAP_REG_ADCD4,  "ad4"),
361 	CPCAP_CHAN(IIO_CURRENT, 5, CPCAP_REG_ADCD5,  "chg_isense"),
362 	CPCAP_CHAN(IIO_CURRENT, 6, CPCAP_REG_ADCD6,  "batti"),
363 	CPCAP_CHAN(IIO_VOLTAGE, 7, CPCAP_REG_ADCD7,  "usb_id"),
364 
365 	/* Bank1 */
366 	CPCAP_CHAN(IIO_CURRENT, 8, CPCAP_REG_ADCD0,  "ad8"),
367 	CPCAP_CHAN(IIO_VOLTAGE, 9, CPCAP_REG_ADCD1,  "ad9"),
368 	CPCAP_CHAN(IIO_VOLTAGE, 10, CPCAP_REG_ADCD2, "licell"),
369 	CPCAP_CHAN(IIO_VOLTAGE, 11, CPCAP_REG_ADCD3, "hv_battp"),
370 	CPCAP_CHAN(IIO_VOLTAGE, 12, CPCAP_REG_ADCD4, "tsx1_ad12"),
371 	CPCAP_CHAN(IIO_VOLTAGE, 13, CPCAP_REG_ADCD5, "tsx2_ad13"),
372 	CPCAP_CHAN(IIO_VOLTAGE, 14, CPCAP_REG_ADCD6, "tsy1_ad14"),
373 	CPCAP_CHAN(IIO_VOLTAGE, 15, CPCAP_REG_ADCD7, "tsy2_ad15"),
374 
375 	/* There are two registers with multiplexed functionality */
376 	CPCAP_CHAN(IIO_VOLTAGE, 16, CPCAP_REG_ADCD0, "chg_vsense"),
377 	CPCAP_CHAN(IIO_CURRENT, 17, CPCAP_REG_ADCD1, "batti2"),
378 };
379 
380 static irqreturn_t cpcap_adc_irq_thread(int irq, void *data)
381 {
382 	struct iio_dev *indio_dev = data;
383 	struct cpcap_adc *ddata = iio_priv(indio_dev);
384 	int error;
385 
386 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
387 				   CPCAP_BIT_ADTRIG_DIS,
388 				   CPCAP_BIT_ADTRIG_DIS);
389 	if (error)
390 		return IRQ_NONE;
391 
392 	ddata->done = true;
393 	wake_up_interruptible(&ddata->wq_data_avail);
394 
395 	return IRQ_HANDLED;
396 }
397 
398 /* ADC calibration functions */
399 static void cpcap_adc_setup_calibrate(struct cpcap_adc *ddata,
400 				      enum cpcap_adc_channel chan)
401 {
402 	unsigned int value = 0;
403 	unsigned long timeout = jiffies + msecs_to_jiffies(3000);
404 	int error;
405 
406 	if ((chan != CPCAP_ADC_CHG_ISENSE) &&
407 	    (chan != CPCAP_ADC_BATTI))
408 		return;
409 
410 	value |= CPCAP_BIT_CAL_MODE | CPCAP_BIT_RAND0;
411 	value |= ((chan << 4) &
412 		  (CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 | CPCAP_BIT_ADA0));
413 
414 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
415 				   CPCAP_BIT_CAL_MODE | CPCAP_BIT_ATOX |
416 				   CPCAP_BIT_ATO3 | CPCAP_BIT_ATO2 |
417 				   CPCAP_BIT_ATO1 | CPCAP_BIT_ATO0 |
418 				   CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 |
419 				   CPCAP_BIT_ADA0 | CPCAP_BIT_AD_SEL1 |
420 				   CPCAP_BIT_RAND1 | CPCAP_BIT_RAND0,
421 				   value);
422 	if (error)
423 		return;
424 
425 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
426 				   CPCAP_BIT_ATOX_PS_FACTOR |
427 				   CPCAP_BIT_ADC_PS_FACTOR1 |
428 				   CPCAP_BIT_ADC_PS_FACTOR0,
429 				   0);
430 	if (error)
431 		return;
432 
433 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
434 				   CPCAP_BIT_ADTRIG_DIS,
435 				   CPCAP_BIT_ADTRIG_DIS);
436 	if (error)
437 		return;
438 
439 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
440 				   CPCAP_BIT_ASC,
441 				   CPCAP_BIT_ASC);
442 	if (error)
443 		return;
444 
445 	do {
446 		schedule_timeout_uninterruptible(1);
447 		error = regmap_read(ddata->reg, CPCAP_REG_ADCC2, &value);
448 		if (error)
449 			return;
450 	} while ((value & CPCAP_BIT_ASC) && time_before(jiffies, timeout));
451 
452 	if (value & CPCAP_BIT_ASC)
453 		dev_err(ddata->dev,
454 			"Timeout waiting for calibration to complete\n");
455 
456 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
457 				   CPCAP_BIT_CAL_MODE, 0);
458 	if (error)
459 		return;
460 }
461 
462 static int cpcap_adc_calibrate_one(struct cpcap_adc *ddata,
463 				   int channel,
464 				   u16 calibration_register,
465 				   int lower_threshold,
466 				   int upper_threshold)
467 {
468 	unsigned int calibration_data[2];
469 	unsigned short cal_data_diff;
470 	int i, error;
471 
472 	for (i = 0; i < CPCAP_ADC_MAX_RETRIES; i++) {
473 		calibration_data[0]  = 0;
474 		calibration_data[1]  = 0;
475 		cal_data_diff = 0;
476 		cpcap_adc_setup_calibrate(ddata, channel);
477 		error = regmap_read(ddata->reg, calibration_register,
478 				    &calibration_data[0]);
479 		if (error)
480 			return error;
481 		cpcap_adc_setup_calibrate(ddata, channel);
482 		error = regmap_read(ddata->reg, calibration_register,
483 				    &calibration_data[1]);
484 		if (error)
485 			return error;
486 
487 		if (calibration_data[0] > calibration_data[1])
488 			cal_data_diff =
489 				calibration_data[0] - calibration_data[1];
490 		else
491 			cal_data_diff =
492 				calibration_data[1] - calibration_data[0];
493 
494 		if (((calibration_data[1] >= lower_threshold) &&
495 		     (calibration_data[1] <= upper_threshold) &&
496 		     (cal_data_diff <= ST_ADC_CALIBRATE_DIFF_THRESHOLD)) ||
497 		    (ddata->vendor == CPCAP_VENDOR_TI)) {
498 			bank_conversion[channel].cal_offset =
499 				((short)calibration_data[1] * -1) + 512;
500 			dev_dbg(ddata->dev, "ch%i calibration complete: %i\n",
501 				channel, bank_conversion[channel].cal_offset);
502 			break;
503 		}
504 		usleep_range(5000, 10000);
505 	}
506 
507 	return 0;
508 }
509 
510 static int cpcap_adc_calibrate(struct cpcap_adc *ddata)
511 {
512 	int error;
513 
514 	error = cpcap_adc_calibrate_one(ddata, CPCAP_ADC_CHG_ISENSE,
515 					CPCAP_REG_ADCAL1,
516 					ST_ADC_CAL_CHRGI_LOW_THRESHOLD,
517 					ST_ADC_CAL_CHRGI_HIGH_THRESHOLD);
518 	if (error)
519 		return error;
520 
521 	error = cpcap_adc_calibrate_one(ddata, CPCAP_ADC_BATTI,
522 					CPCAP_REG_ADCAL2,
523 					ST_ADC_CAL_BATTI_LOW_THRESHOLD,
524 					ST_ADC_CAL_BATTI_HIGH_THRESHOLD);
525 	if (error)
526 		return error;
527 
528 	return 0;
529 }
530 
531 /* ADC setup, read and scale functions */
532 static void cpcap_adc_setup_bank(struct cpcap_adc *ddata,
533 				 struct cpcap_adc_request *req)
534 {
535 	const struct cpcap_adc_ato *ato = ddata->ato;
536 	unsigned short value1 = 0;
537 	unsigned short value2 = 0;
538 	int error;
539 
540 	if (!ato)
541 		return;
542 
543 	switch (req->channel) {
544 	case CPCAP_ADC_AD8 ... CPCAP_ADC_TSY2_AD15:
545 		value1 |= CPCAP_BIT_AD_SEL1;
546 		break;
547 	case CPCAP_ADC_BATTP_PI16 ... CPCAP_ADC_BATTI_PI17:
548 		value1 |= CPCAP_BIT_RAND1;
549 	default:
550 		break;
551 	}
552 
553 	switch (req->timing) {
554 	case CPCAP_ADC_TIMING_IN:
555 		value1 |= ato->ato_in;
556 		value1 |= ato->atox_in;
557 		value2 |= ato->adc_ps_factor_in;
558 		value2 |= ato->atox_ps_factor_in;
559 		break;
560 	case CPCAP_ADC_TIMING_OUT:
561 		value1 |= ato->ato_out;
562 		value1 |= ato->atox_out;
563 		value2 |= ato->adc_ps_factor_out;
564 		value2 |= ato->atox_ps_factor_out;
565 		break;
566 
567 	case CPCAP_ADC_TIMING_IMM:
568 	default:
569 		break;
570 	}
571 
572 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
573 				   CPCAP_BIT_CAL_MODE | CPCAP_BIT_ATOX |
574 				   CPCAP_BIT_ATO3 | CPCAP_BIT_ATO2 |
575 				   CPCAP_BIT_ATO1 | CPCAP_BIT_ATO0 |
576 				   CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 |
577 				   CPCAP_BIT_ADA0 | CPCAP_BIT_AD_SEL1 |
578 				   CPCAP_BIT_RAND1 | CPCAP_BIT_RAND0,
579 				   value1);
580 	if (error)
581 		return;
582 
583 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
584 				   CPCAP_BIT_ATOX_PS_FACTOR |
585 				   CPCAP_BIT_ADC_PS_FACTOR1 |
586 				   CPCAP_BIT_ADC_PS_FACTOR0,
587 				   value2);
588 	if (error)
589 		return;
590 
591 	if (req->timing == CPCAP_ADC_TIMING_IMM) {
592 		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
593 					   CPCAP_BIT_ADTRIG_DIS,
594 					   CPCAP_BIT_ADTRIG_DIS);
595 		if (error)
596 			return;
597 
598 		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
599 					   CPCAP_BIT_ASC,
600 					   CPCAP_BIT_ASC);
601 		if (error)
602 			return;
603 	} else {
604 		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
605 					   CPCAP_BIT_ADTRIG_ONESHOT,
606 					   CPCAP_BIT_ADTRIG_ONESHOT);
607 		if (error)
608 			return;
609 
610 		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
611 					   CPCAP_BIT_ADTRIG_DIS, 0);
612 		if (error)
613 			return;
614 	}
615 }
616 
617 /*
618  * Occasionally the ADC does not seem to start and there will be no
619  * interrupt. Let's re-init interrupt to prevent the ADC from hanging
620  * for the next request. It is unclear why this happens, but the next
621  * request will usually work after doing this.
622  */
623 static void cpcap_adc_quirk_reset_lost_irq(struct cpcap_adc *ddata)
624 {
625 	int error;
626 
627 	dev_info(ddata->dev, "lost ADC irq, attempting to reinit\n");
628 	disable_irq(ddata->irq);
629 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
630 				   CPCAP_BIT_ADTRIG_DIS,
631 				   CPCAP_BIT_ADTRIG_DIS);
632 	if (error)
633 		dev_warn(ddata->dev, "%s reset failed: %i\n",
634 			 __func__, error);
635 	enable_irq(ddata->irq);
636 }
637 
638 static int cpcap_adc_start_bank(struct cpcap_adc *ddata,
639 				struct cpcap_adc_request *req)
640 {
641 	int i, error;
642 
643 	req->timing = CPCAP_ADC_TIMING_IMM;
644 	ddata->done = false;
645 
646 	for (i = 0; i < CPCAP_ADC_MAX_RETRIES; i++) {
647 		cpcap_adc_setup_bank(ddata, req);
648 		error = wait_event_interruptible_timeout(ddata->wq_data_avail,
649 							 ddata->done,
650 							 msecs_to_jiffies(50));
651 		if (error > 0)
652 			return 0;
653 
654 		if (error == 0) {
655 			cpcap_adc_quirk_reset_lost_irq(ddata);
656 			error = -ETIMEDOUT;
657 			continue;
658 		}
659 
660 		if (error < 0)
661 			return error;
662 	}
663 
664 	return error;
665 }
666 
667 static void cpcap_adc_phase(struct cpcap_adc_request *req)
668 {
669 	const struct cpcap_adc_conversion_tbl *conv_tbl = req->conv_tbl;
670 	const struct cpcap_adc_phasing_tbl *phase_tbl = req->phase_tbl;
671 	int index = req->channel;
672 
673 	/* Remuxed channels 16 and 17 use BATTP and BATTI entries */
674 	switch (req->channel) {
675 	case CPCAP_ADC_BATTP:
676 	case CPCAP_ADC_BATTP_PI16:
677 		index = req->bank_index;
678 		req->result -= phase_tbl[index].offset;
679 		req->result -= CPCAP_FOUR_POINT_TWO_ADC;
680 		req->result *= phase_tbl[index].multiplier;
681 		if (phase_tbl[index].divider == 0)
682 			return;
683 		req->result /= phase_tbl[index].divider;
684 		req->result += CPCAP_FOUR_POINT_TWO_ADC;
685 		break;
686 	case CPCAP_ADC_BATTI_PI17:
687 		index = req->bank_index;
688 		/* fallthrough */
689 	default:
690 		req->result += conv_tbl[index].cal_offset;
691 		req->result += conv_tbl[index].align_offset;
692 		req->result *= phase_tbl[index].multiplier;
693 		if (phase_tbl[index].divider == 0)
694 			return;
695 		req->result /= phase_tbl[index].divider;
696 		req->result += phase_tbl[index].offset;
697 		break;
698 	}
699 
700 	if (req->result < phase_tbl[index].min)
701 		req->result = phase_tbl[index].min;
702 	else if (req->result > phase_tbl[index].max)
703 		req->result = phase_tbl[index].max;
704 }
705 
706 /* Looks up temperatures in a table and calculates averages if needed */
707 static int cpcap_adc_table_to_millicelcius(unsigned short value)
708 {
709 	int i, result = 0, alpha;
710 
711 	if (value <= temp_map[CPCAP_MAX_TEMP_LVL - 1][0])
712 		return temp_map[CPCAP_MAX_TEMP_LVL - 1][1];
713 
714 	if (value >= temp_map[0][0])
715 		return temp_map[0][1];
716 
717 	for (i = 0; i < CPCAP_MAX_TEMP_LVL - 1; i++) {
718 		if ((value <= temp_map[i][0]) &&
719 		    (value >= temp_map[i + 1][0])) {
720 			if (value == temp_map[i][0]) {
721 				result = temp_map[i][1];
722 			} else if (value == temp_map[i + 1][0]) {
723 				result = temp_map[i + 1][1];
724 			} else {
725 				alpha = ((value - temp_map[i][0]) * 1000) /
726 					(temp_map[i + 1][0] - temp_map[i][0]);
727 
728 				result = temp_map[i][1] +
729 					((alpha * (temp_map[i + 1][1] -
730 						 temp_map[i][1])) / 1000);
731 			}
732 			break;
733 		}
734 	}
735 
736 	return result;
737 }
738 
739 static void cpcap_adc_convert(struct cpcap_adc_request *req)
740 {
741 	const struct cpcap_adc_conversion_tbl *conv_tbl = req->conv_tbl;
742 	int index = req->channel;
743 
744 	/* Remuxed channels 16 and 17 use BATTP and BATTI entries */
745 	switch (req->channel) {
746 	case CPCAP_ADC_BATTP_PI16:
747 		index = CPCAP_ADC_BATTP;
748 		break;
749 	case CPCAP_ADC_BATTI_PI17:
750 		index = CPCAP_ADC_BATTI;
751 		break;
752 	default:
753 		break;
754 	}
755 
756 	/* No conversion for raw channels */
757 	if (conv_tbl[index].conv_type == IIO_CHAN_INFO_RAW)
758 		return;
759 
760 	/* Temperatures use a lookup table instead of conversion table */
761 	if ((req->channel == CPCAP_ADC_AD0_BATTDETB) ||
762 	    (req->channel == CPCAP_ADC_AD3)) {
763 		req->result =
764 			cpcap_adc_table_to_millicelcius(req->result);
765 
766 		return;
767 	}
768 
769 	/* All processed channels use a conversion table */
770 	req->result *= conv_tbl[index].multiplier;
771 	if (conv_tbl[index].divider == 0)
772 		return;
773 	req->result /= conv_tbl[index].divider;
774 	req->result += conv_tbl[index].conv_offset;
775 }
776 
777 /*
778  * REVISIT: Check if timed sampling can use multiple channels at the
779  * same time. If not, replace channel_mask with just channel.
780  */
781 static int cpcap_adc_read_bank_scaled(struct cpcap_adc *ddata,
782 				      struct cpcap_adc_request *req)
783 {
784 	int calibration_data, error, addr;
785 
786 	if (ddata->vendor == CPCAP_VENDOR_TI) {
787 		error = regmap_read(ddata->reg, CPCAP_REG_ADCAL1,
788 				    &calibration_data);
789 		if (error)
790 			return error;
791 		bank_conversion[CPCAP_ADC_CHG_ISENSE].cal_offset =
792 			((short)calibration_data * -1) + 512;
793 
794 		error = regmap_read(ddata->reg, CPCAP_REG_ADCAL2,
795 				    &calibration_data);
796 		if (error)
797 			return error;
798 		bank_conversion[CPCAP_ADC_BATTI].cal_offset =
799 			((short)calibration_data * -1) + 512;
800 	}
801 
802 	addr = CPCAP_REG_ADCD0 + req->bank_index * 4;
803 
804 	error = regmap_read(ddata->reg, addr, &req->result);
805 	if (error)
806 		return error;
807 
808 	req->result &= 0x3ff;
809 	cpcap_adc_phase(req);
810 	cpcap_adc_convert(req);
811 
812 	return 0;
813 }
814 
815 static int cpcap_adc_init_request(struct cpcap_adc_request *req,
816 				  int channel)
817 {
818 	req->channel = channel;
819 	req->phase_tbl = bank_phasing;
820 	req->conv_tbl = bank_conversion;
821 
822 	switch (channel) {
823 	case CPCAP_ADC_AD0_BATTDETB ... CPCAP_ADC_USB_ID:
824 		req->bank_index = channel;
825 		break;
826 	case CPCAP_ADC_AD8 ... CPCAP_ADC_TSY2_AD15:
827 		req->bank_index = channel - 8;
828 		break;
829 	case CPCAP_ADC_BATTP_PI16:
830 		req->bank_index = CPCAP_ADC_BATTP;
831 		break;
832 	case CPCAP_ADC_BATTI_PI17:
833 		req->bank_index = CPCAP_ADC_BATTI;
834 		break;
835 	default:
836 		return -EINVAL;
837 	}
838 
839 	return 0;
840 }
841 
842 static int cpcap_adc_read(struct iio_dev *indio_dev,
843 			  struct iio_chan_spec const *chan,
844 			  int *val, int *val2, long mask)
845 {
846 	struct cpcap_adc *ddata = iio_priv(indio_dev);
847 	struct cpcap_adc_request req;
848 	int error;
849 
850 	error = cpcap_adc_init_request(&req, chan->channel);
851 	if (error)
852 		return error;
853 
854 	switch (mask) {
855 	case IIO_CHAN_INFO_RAW:
856 		mutex_lock(&ddata->lock);
857 		error = cpcap_adc_start_bank(ddata, &req);
858 		if (error)
859 			goto err_unlock;
860 		error = regmap_read(ddata->reg, chan->address, val);
861 		if (error)
862 			goto err_unlock;
863 		mutex_unlock(&ddata->lock);
864 		break;
865 	case IIO_CHAN_INFO_PROCESSED:
866 		mutex_lock(&ddata->lock);
867 		error = cpcap_adc_start_bank(ddata, &req);
868 		if (error)
869 			goto err_unlock;
870 		error = cpcap_adc_read_bank_scaled(ddata, &req);
871 		if (error)
872 			goto err_unlock;
873 		mutex_unlock(&ddata->lock);
874 		*val = req.result;
875 		break;
876 	default:
877 		return -EINVAL;
878 	}
879 
880 	return IIO_VAL_INT;
881 
882 err_unlock:
883 	mutex_unlock(&ddata->lock);
884 	dev_err(ddata->dev, "error reading ADC: %i\n", error);
885 
886 	return error;
887 }
888 
889 static const struct iio_info cpcap_adc_info = {
890 	.read_raw = &cpcap_adc_read,
891 	.driver_module = THIS_MODULE,
892 };
893 
894 /*
895  * Configuration for Motorola mapphone series such as droid 4.
896  * Copied from the Motorola mapphone kernel tree.
897  */
898 static const struct cpcap_adc_ato mapphone_adc = {
899 	.ato_in = 0x0480,
900 	.atox_in = 0,
901 	.adc_ps_factor_in = 0x0200,
902 	.atox_ps_factor_in = 0,
903 	.ato_out = 0,
904 	.atox_out = 0,
905 	.adc_ps_factor_out = 0,
906 	.atox_ps_factor_out = 0,
907 };
908 
909 static const struct of_device_id cpcap_adc_id_table[] = {
910 	{
911 		.compatible = "motorola,cpcap-adc",
912 	},
913 	{
914 		.compatible = "motorola,mapphone-cpcap-adc",
915 		.data = &mapphone_adc,
916 	},
917 	{ /* sentinel */ },
918 };
919 MODULE_DEVICE_TABLE(of, cpcap_adc_id_table);
920 
921 static int cpcap_adc_probe(struct platform_device *pdev)
922 {
923 	const struct of_device_id *match;
924 	struct cpcap_adc *ddata;
925 	struct iio_dev *indio_dev;
926 	int error;
927 
928 	match = of_match_device(of_match_ptr(cpcap_adc_id_table),
929 				&pdev->dev);
930 	if (!match)
931 		return -EINVAL;
932 
933 	if (!match->data) {
934 		dev_err(&pdev->dev, "no configuration data found\n");
935 
936 		return -ENODEV;
937 	}
938 
939 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*ddata));
940 	if (!indio_dev) {
941 		dev_err(&pdev->dev, "failed to allocate iio device\n");
942 
943 		return -ENOMEM;
944 	}
945 	ddata = iio_priv(indio_dev);
946 	ddata->ato = match->data;
947 	ddata->dev = &pdev->dev;
948 
949 	mutex_init(&ddata->lock);
950 	init_waitqueue_head(&ddata->wq_data_avail);
951 
952 	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
953 	indio_dev->dev.parent = &pdev->dev;
954 	indio_dev->dev.of_node = pdev->dev.of_node;
955 	indio_dev->channels = cpcap_adc_channels;
956 	indio_dev->num_channels = ARRAY_SIZE(cpcap_adc_channels);
957 	indio_dev->name = dev_name(&pdev->dev);
958 	indio_dev->info = &cpcap_adc_info;
959 
960 	ddata->reg = dev_get_regmap(pdev->dev.parent, NULL);
961 	if (!ddata->reg)
962 		return -ENODEV;
963 
964 	error = cpcap_get_vendor(ddata->dev, ddata->reg, &ddata->vendor);
965 	if (error)
966 		return error;
967 
968 	platform_set_drvdata(pdev, indio_dev);
969 
970 	ddata->irq = platform_get_irq_byname(pdev, "adcdone");
971 	if (!ddata->irq)
972 		return -ENODEV;
973 
974 	error = devm_request_threaded_irq(&pdev->dev, ddata->irq, NULL,
975 					  cpcap_adc_irq_thread,
976 					  IRQF_TRIGGER_NONE,
977 					  "cpcap-adc", indio_dev);
978 	if (error) {
979 		dev_err(&pdev->dev, "could not get irq: %i\n",
980 			error);
981 
982 		return error;
983 	}
984 
985 	error = cpcap_adc_calibrate(ddata);
986 	if (error)
987 		return error;
988 
989 	dev_info(&pdev->dev, "CPCAP ADC device probed\n");
990 
991 	return devm_iio_device_register(&pdev->dev, indio_dev);
992 }
993 
994 static struct platform_driver cpcap_adc_driver = {
995 	.driver = {
996 		.name = "cpcap_adc",
997 		.of_match_table = of_match_ptr(cpcap_adc_id_table),
998 	},
999 	.probe = cpcap_adc_probe,
1000 };
1001 
1002 module_platform_driver(cpcap_adc_driver);
1003 
1004 MODULE_ALIAS("platform:cpcap_adc");
1005 MODULE_DESCRIPTION("CPCAP ADC driver");
1006 MODULE_AUTHOR("Tony Lindgren <tony@atomide.com");
1007 MODULE_LICENSE("GPL v2");
1008