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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2017 Tony Lindgren <tony@atomide.com>
4  *
5  * Rewritten for Linux IIO framework with some code based on
6  * earlier driver found in the Motorola Linux kernel:
7  *
8  * Copyright (C) 2009-2010 Motorola, Inc.
9  */
10 
11 #include <linux/delay.h>
12 #include <linux/device.h>
13 #include <linux/err.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/platform_device.h>
20 #include <linux/property.h>
21 #include <linux/regmap.h>
22 
23 #include <linux/iio/buffer.h>
24 #include <linux/iio/driver.h>
25 #include <linux/iio/iio.h>
26 #include <linux/iio/kfifo_buf.h>
27 #include <linux/mfd/motorola-cpcap.h>
28 
29 /* Register CPCAP_REG_ADCC1 bits */
30 #define CPCAP_BIT_ADEN_AUTO_CLR		BIT(15)	/* Currently unused */
31 #define CPCAP_BIT_CAL_MODE		BIT(14) /* Set with BIT_RAND0 */
32 #define CPCAP_BIT_ADC_CLK_SEL1		BIT(13)	/* Currently unused */
33 #define CPCAP_BIT_ADC_CLK_SEL0		BIT(12)	/* Currently unused */
34 #define CPCAP_BIT_ATOX			BIT(11)
35 #define CPCAP_BIT_ATO3			BIT(10)
36 #define CPCAP_BIT_ATO2			BIT(9)
37 #define CPCAP_BIT_ATO1			BIT(8)
38 #define CPCAP_BIT_ATO0			BIT(7)
39 #define CPCAP_BIT_ADA2			BIT(6)
40 #define CPCAP_BIT_ADA1			BIT(5)
41 #define CPCAP_BIT_ADA0			BIT(4)
42 #define CPCAP_BIT_AD_SEL1		BIT(3)	/* Set for bank1 */
43 #define CPCAP_BIT_RAND1			BIT(2)	/* Set for channel 16 & 17 */
44 #define CPCAP_BIT_RAND0			BIT(1)	/* Set with CAL_MODE */
45 #define CPCAP_BIT_ADEN			BIT(0)	/* Currently unused */
46 
47 #define CPCAP_REG_ADCC1_DEFAULTS	(CPCAP_BIT_ADEN_AUTO_CLR | \
48 					 CPCAP_BIT_ADC_CLK_SEL0 |  \
49 					 CPCAP_BIT_RAND1)
50 
51 /* Register CPCAP_REG_ADCC2 bits */
52 #define CPCAP_BIT_CAL_FACTOR_ENABLE	BIT(15)	/* Currently unused */
53 #define CPCAP_BIT_BATDETB_EN		BIT(14)	/* Currently unused */
54 #define CPCAP_BIT_ADTRIG_ONESHOT	BIT(13)	/* Set for !TIMING_IMM */
55 #define CPCAP_BIT_ASC			BIT(12)	/* Set for TIMING_IMM */
56 #define CPCAP_BIT_ATOX_PS_FACTOR	BIT(11)
57 #define CPCAP_BIT_ADC_PS_FACTOR1	BIT(10)
58 #define CPCAP_BIT_ADC_PS_FACTOR0	BIT(9)
59 #define CPCAP_BIT_AD4_SELECT		BIT(8)	/* Currently unused */
60 #define CPCAP_BIT_ADC_BUSY		BIT(7)	/* Currently unused */
61 #define CPCAP_BIT_THERMBIAS_EN		BIT(6)	/* Bias for AD0_BATTDETB */
62 #define CPCAP_BIT_ADTRIG_DIS		BIT(5)	/* Disable interrupt */
63 #define CPCAP_BIT_LIADC			BIT(4)	/* Currently unused */
64 #define CPCAP_BIT_TS_REFEN		BIT(3)	/* Currently unused */
65 #define CPCAP_BIT_TS_M2			BIT(2)	/* Currently unused */
66 #define CPCAP_BIT_TS_M1			BIT(1)	/* Currently unused */
67 #define CPCAP_BIT_TS_M0			BIT(0)	/* Currently unused */
68 
69 #define CPCAP_REG_ADCC2_DEFAULTS	(CPCAP_BIT_AD4_SELECT | \
70 					 CPCAP_BIT_ADTRIG_DIS | \
71 					 CPCAP_BIT_LIADC | \
72 					 CPCAP_BIT_TS_M2 | \
73 					 CPCAP_BIT_TS_M1)
74 
75 #define CPCAP_MAX_TEMP_LVL		27
76 #define CPCAP_FOUR_POINT_TWO_ADC	801
77 #define ST_ADC_CAL_CHRGI_HIGH_THRESHOLD	530
78 #define ST_ADC_CAL_CHRGI_LOW_THRESHOLD	494
79 #define ST_ADC_CAL_BATTI_HIGH_THRESHOLD	530
80 #define ST_ADC_CAL_BATTI_LOW_THRESHOLD	494
81 #define ST_ADC_CALIBRATE_DIFF_THRESHOLD	3
82 
83 #define CPCAP_ADC_MAX_RETRIES		5	/* Calibration */
84 
85 /*
86  * struct cpcap_adc_ato - timing settings for cpcap adc
87  *
88  * Unfortunately no cpcap documentation available, please document when
89  * using these.
90  */
91 struct cpcap_adc_ato {
92 	unsigned short ato_in;
93 	unsigned short atox_in;
94 	unsigned short adc_ps_factor_in;
95 	unsigned short atox_ps_factor_in;
96 	unsigned short ato_out;
97 	unsigned short atox_out;
98 	unsigned short adc_ps_factor_out;
99 	unsigned short atox_ps_factor_out;
100 };
101 
102 /**
103  * struct cpcap-adc - cpcap adc device driver data
104  * @reg: cpcap regmap
105  * @dev: struct device
106  * @vendor: cpcap vendor
107  * @irq: interrupt
108  * @lock: mutex
109  * @ato: request timings
110  * @wq_data_avail: work queue
111  * @done: work done
112  */
113 struct cpcap_adc {
114 	struct regmap *reg;
115 	struct device *dev;
116 	u16 vendor;
117 	int irq;
118 	struct mutex lock;	/* ADC register access lock */
119 	const struct cpcap_adc_ato *ato;
120 	wait_queue_head_t wq_data_avail;
121 	bool done;
122 };
123 
124 /*
125  * enum cpcap_adc_channel - cpcap adc channels
126  */
127 enum cpcap_adc_channel {
128 	/* Bank0 channels */
129 	CPCAP_ADC_AD0,		/* Battery temperature */
130 	CPCAP_ADC_BATTP,	/* Battery voltage */
131 	CPCAP_ADC_VBUS,		/* USB VBUS voltage */
132 	CPCAP_ADC_AD3,		/* Die temperature when charging */
133 	CPCAP_ADC_BPLUS_AD4,	/* Another battery or system voltage */
134 	CPCAP_ADC_CHG_ISENSE,	/* Calibrated charge current */
135 	CPCAP_ADC_BATTI,	/* Calibrated system current */
136 	CPCAP_ADC_USB_ID,	/* USB OTG ID, unused on droid 4? */
137 
138 	/* Bank1 channels */
139 	CPCAP_ADC_AD8,		/* Seems unused */
140 	CPCAP_ADC_AD9,		/* Seems unused */
141 	CPCAP_ADC_LICELL,	/* Maybe system voltage? Always 3V */
142 	CPCAP_ADC_HV_BATTP,	/* Another battery detection? */
143 	CPCAP_ADC_TSX1_AD12,	/* Seems unused, for touchscreen? */
144 	CPCAP_ADC_TSX2_AD13,	/* Seems unused, for touchscreen? */
145 	CPCAP_ADC_TSY1_AD14,	/* Seems unused, for touchscreen? */
146 	CPCAP_ADC_TSY2_AD15,	/* Seems unused, for touchscreen? */
147 
148 	/* Remuxed channels using bank0 entries */
149 	CPCAP_ADC_BATTP_PI16,	/* Alternative mux mode for BATTP */
150 	CPCAP_ADC_BATTI_PI17,	/* Alternative mux mode for BATTI */
151 
152 	CPCAP_ADC_CHANNEL_NUM,
153 };
154 
155 /*
156  * enum cpcap_adc_timing - cpcap adc timing options
157  *
158  * CPCAP_ADC_TIMING_IMM seems to be immediate with no timings.
159  * Please document when using.
160  */
161 enum cpcap_adc_timing {
162 	CPCAP_ADC_TIMING_IMM,
163 	CPCAP_ADC_TIMING_IN,
164 	CPCAP_ADC_TIMING_OUT,
165 };
166 
167 /**
168  * struct cpcap_adc_phasing_tbl - cpcap phasing table
169  * @offset: offset in the phasing table
170  * @multiplier: multiplier in the phasing table
171  * @divider: divider in the phasing table
172  * @min: minimum value
173  * @max: maximum value
174  */
175 struct cpcap_adc_phasing_tbl {
176 	short offset;
177 	unsigned short multiplier;
178 	unsigned short divider;
179 	short min;
180 	short max;
181 };
182 
183 /**
184  * struct cpcap_adc_conversion_tbl - cpcap conversion table
185  * @conv_type: conversion type
186  * @align_offset: align offset
187  * @conv_offset: conversion offset
188  * @cal_offset: calibration offset
189  * @multiplier: conversion multiplier
190  * @divider: conversion divider
191  */
192 struct cpcap_adc_conversion_tbl {
193 	enum iio_chan_info_enum conv_type;
194 	int align_offset;
195 	int conv_offset;
196 	int cal_offset;
197 	int multiplier;
198 	int divider;
199 };
200 
201 /**
202  * struct cpcap_adc_request - cpcap adc request
203  * @channel: request channel
204  * @phase_tbl: channel phasing table
205  * @conv_tbl: channel conversion table
206  * @bank_index: channel index within the bank
207  * @timing: timing settings
208  * @result: result
209  */
210 struct cpcap_adc_request {
211 	int channel;
212 	const struct cpcap_adc_phasing_tbl *phase_tbl;
213 	const struct cpcap_adc_conversion_tbl *conv_tbl;
214 	int bank_index;
215 	enum cpcap_adc_timing timing;
216 	int result;
217 };
218 
219 /* Phasing table for channels. Note that channels 16 & 17 use BATTP and BATTI */
220 static const struct cpcap_adc_phasing_tbl bank_phasing[] = {
221 	/* Bank0 */
222 	[CPCAP_ADC_AD0] =          {0, 0x80, 0x80,    0, 1023},
223 	[CPCAP_ADC_BATTP] =        {0, 0x80, 0x80,    0, 1023},
224 	[CPCAP_ADC_VBUS] =         {0, 0x80, 0x80,    0, 1023},
225 	[CPCAP_ADC_AD3] =          {0, 0x80, 0x80,    0, 1023},
226 	[CPCAP_ADC_BPLUS_AD4] =    {0, 0x80, 0x80,    0, 1023},
227 	[CPCAP_ADC_CHG_ISENSE] =   {0, 0x80, 0x80, -512,  511},
228 	[CPCAP_ADC_BATTI] =        {0, 0x80, 0x80, -512,  511},
229 	[CPCAP_ADC_USB_ID] =       {0, 0x80, 0x80,    0, 1023},
230 
231 	/* Bank1 */
232 	[CPCAP_ADC_AD8] =          {0, 0x80, 0x80,    0, 1023},
233 	[CPCAP_ADC_AD9] =          {0, 0x80, 0x80,    0, 1023},
234 	[CPCAP_ADC_LICELL] =       {0, 0x80, 0x80,    0, 1023},
235 	[CPCAP_ADC_HV_BATTP] =     {0, 0x80, 0x80,    0, 1023},
236 	[CPCAP_ADC_TSX1_AD12] =    {0, 0x80, 0x80,    0, 1023},
237 	[CPCAP_ADC_TSX2_AD13] =    {0, 0x80, 0x80,    0, 1023},
238 	[CPCAP_ADC_TSY1_AD14] =    {0, 0x80, 0x80,    0, 1023},
239 	[CPCAP_ADC_TSY2_AD15] =    {0, 0x80, 0x80,    0, 1023},
240 };
241 
242 /*
243  * Conversion table for channels. Updated during init based on calibration.
244  * Here too channels 16 & 17 use BATTP and BATTI.
245  */
246 static struct cpcap_adc_conversion_tbl bank_conversion[] = {
247 	/* Bank0 */
248 	[CPCAP_ADC_AD0] = {
249 		IIO_CHAN_INFO_PROCESSED,    0,    0, 0,     1,    1,
250 	},
251 	[CPCAP_ADC_BATTP] = {
252 		IIO_CHAN_INFO_PROCESSED,    0, 2400, 0,  2300, 1023,
253 	},
254 	[CPCAP_ADC_VBUS] = {
255 		IIO_CHAN_INFO_PROCESSED,    0,    0, 0, 10000, 1023,
256 	},
257 	[CPCAP_ADC_AD3] = {
258 		IIO_CHAN_INFO_PROCESSED,    0,    0, 0,     1,    1,
259 		},
260 	[CPCAP_ADC_BPLUS_AD4] = {
261 		IIO_CHAN_INFO_PROCESSED,    0, 2400, 0,  2300, 1023,
262 	},
263 	[CPCAP_ADC_CHG_ISENSE] = {
264 		IIO_CHAN_INFO_PROCESSED, -512,    2, 0,  5000, 1023,
265 	},
266 	[CPCAP_ADC_BATTI] = {
267 		IIO_CHAN_INFO_PROCESSED, -512,    2, 0,  5000, 1023,
268 	},
269 	[CPCAP_ADC_USB_ID] = {
270 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
271 	},
272 
273 	/* Bank1 */
274 	[CPCAP_ADC_AD8] = {
275 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
276 	},
277 	[CPCAP_ADC_AD9] = {
278 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
279 	},
280 	[CPCAP_ADC_LICELL] = {
281 		IIO_CHAN_INFO_PROCESSED,    0,    0, 0,  3400, 1023,
282 	},
283 	[CPCAP_ADC_HV_BATTP] = {
284 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
285 	},
286 	[CPCAP_ADC_TSX1_AD12] = {
287 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
288 	},
289 	[CPCAP_ADC_TSX2_AD13] = {
290 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
291 	},
292 	[CPCAP_ADC_TSY1_AD14] = {
293 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
294 	},
295 	[CPCAP_ADC_TSY2_AD15] = {
296 		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
297 	},
298 };
299 
300 /*
301  * Temperature lookup table of register values to milliCelcius.
302  * REVISIT: Check the duplicate 0x3ff entry in a freezer
303  */
304 static const int temp_map[CPCAP_MAX_TEMP_LVL][2] = {
305 	{ 0x03ff, -40000 },
306 	{ 0x03ff, -35000 },
307 	{ 0x03ef, -30000 },
308 	{ 0x03b2, -25000 },
309 	{ 0x036c, -20000 },
310 	{ 0x0320, -15000 },
311 	{ 0x02d0, -10000 },
312 	{ 0x027f, -5000 },
313 	{ 0x022f, 0 },
314 	{ 0x01e4, 5000 },
315 	{ 0x019f, 10000 },
316 	{ 0x0161, 15000 },
317 	{ 0x012b, 20000 },
318 	{ 0x00fc, 25000 },
319 	{ 0x00d4, 30000 },
320 	{ 0x00b2, 35000 },
321 	{ 0x0095, 40000 },
322 	{ 0x007d, 45000 },
323 	{ 0x0069, 50000 },
324 	{ 0x0059, 55000 },
325 	{ 0x004b, 60000 },
326 	{ 0x003f, 65000 },
327 	{ 0x0036, 70000 },
328 	{ 0x002e, 75000 },
329 	{ 0x0027, 80000 },
330 	{ 0x0022, 85000 },
331 	{ 0x001d, 90000 },
332 };
333 
334 #define CPCAP_CHAN(_type, _index, _address, _datasheet_name) {	\
335 	.type = (_type), \
336 	.address = (_address), \
337 	.indexed = 1, \
338 	.channel = (_index), \
339 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
340 			      BIT(IIO_CHAN_INFO_PROCESSED), \
341 	.scan_index = (_index), \
342 	.scan_type = { \
343 		.sign = 'u', \
344 		.realbits = 10, \
345 		.storagebits = 16, \
346 		.endianness = IIO_CPU, \
347 	}, \
348 	.datasheet_name = (_datasheet_name), \
349 }
350 
351 /*
352  * The datasheet names are from Motorola mapphone Linux kernel except
353  * for the last two which might be uncalibrated charge voltage and
354  * current.
355  */
356 static const struct iio_chan_spec cpcap_adc_channels[] = {
357 	/* Bank0 */
358 	CPCAP_CHAN(IIO_TEMP,    0, CPCAP_REG_ADCD0,  "battdetb"),
359 	CPCAP_CHAN(IIO_VOLTAGE, 1, CPCAP_REG_ADCD1,  "battp"),
360 	CPCAP_CHAN(IIO_VOLTAGE, 2, CPCAP_REG_ADCD2,  "vbus"),
361 	CPCAP_CHAN(IIO_TEMP,    3, CPCAP_REG_ADCD3,  "ad3"),
362 	CPCAP_CHAN(IIO_VOLTAGE, 4, CPCAP_REG_ADCD4,  "ad4"),
363 	CPCAP_CHAN(IIO_CURRENT, 5, CPCAP_REG_ADCD5,  "chg_isense"),
364 	CPCAP_CHAN(IIO_CURRENT, 6, CPCAP_REG_ADCD6,  "batti"),
365 	CPCAP_CHAN(IIO_VOLTAGE, 7, CPCAP_REG_ADCD7,  "usb_id"),
366 
367 	/* Bank1 */
368 	CPCAP_CHAN(IIO_CURRENT, 8, CPCAP_REG_ADCD0,  "ad8"),
369 	CPCAP_CHAN(IIO_VOLTAGE, 9, CPCAP_REG_ADCD1,  "ad9"),
370 	CPCAP_CHAN(IIO_VOLTAGE, 10, CPCAP_REG_ADCD2, "licell"),
371 	CPCAP_CHAN(IIO_VOLTAGE, 11, CPCAP_REG_ADCD3, "hv_battp"),
372 	CPCAP_CHAN(IIO_VOLTAGE, 12, CPCAP_REG_ADCD4, "tsx1_ad12"),
373 	CPCAP_CHAN(IIO_VOLTAGE, 13, CPCAP_REG_ADCD5, "tsx2_ad13"),
374 	CPCAP_CHAN(IIO_VOLTAGE, 14, CPCAP_REG_ADCD6, "tsy1_ad14"),
375 	CPCAP_CHAN(IIO_VOLTAGE, 15, CPCAP_REG_ADCD7, "tsy2_ad15"),
376 
377 	/* There are two registers with multiplexed functionality */
378 	CPCAP_CHAN(IIO_VOLTAGE, 16, CPCAP_REG_ADCD0, "chg_vsense"),
379 	CPCAP_CHAN(IIO_CURRENT, 17, CPCAP_REG_ADCD1, "batti2"),
380 };
381 
cpcap_adc_irq_thread(int irq,void * data)382 static irqreturn_t cpcap_adc_irq_thread(int irq, void *data)
383 {
384 	struct iio_dev *indio_dev = data;
385 	struct cpcap_adc *ddata = iio_priv(indio_dev);
386 	int error;
387 
388 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
389 				   CPCAP_BIT_ADTRIG_DIS,
390 				   CPCAP_BIT_ADTRIG_DIS);
391 	if (error)
392 		return IRQ_NONE;
393 
394 	ddata->done = true;
395 	wake_up_interruptible(&ddata->wq_data_avail);
396 
397 	return IRQ_HANDLED;
398 }
399 
400 /* ADC calibration functions */
cpcap_adc_setup_calibrate(struct cpcap_adc * ddata,enum cpcap_adc_channel chan)401 static void cpcap_adc_setup_calibrate(struct cpcap_adc *ddata,
402 				      enum cpcap_adc_channel chan)
403 {
404 	unsigned int value = 0;
405 	unsigned long timeout = jiffies + msecs_to_jiffies(3000);
406 	int error;
407 
408 	if ((chan != CPCAP_ADC_CHG_ISENSE) &&
409 	    (chan != CPCAP_ADC_BATTI))
410 		return;
411 
412 	value |= CPCAP_BIT_CAL_MODE | CPCAP_BIT_RAND0;
413 	value |= ((chan << 4) &
414 		  (CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 | CPCAP_BIT_ADA0));
415 
416 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
417 				   CPCAP_BIT_CAL_MODE | CPCAP_BIT_ATOX |
418 				   CPCAP_BIT_ATO3 | CPCAP_BIT_ATO2 |
419 				   CPCAP_BIT_ATO1 | CPCAP_BIT_ATO0 |
420 				   CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 |
421 				   CPCAP_BIT_ADA0 | CPCAP_BIT_AD_SEL1 |
422 				   CPCAP_BIT_RAND1 | CPCAP_BIT_RAND0,
423 				   value);
424 	if (error)
425 		return;
426 
427 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
428 				   CPCAP_BIT_ATOX_PS_FACTOR |
429 				   CPCAP_BIT_ADC_PS_FACTOR1 |
430 				   CPCAP_BIT_ADC_PS_FACTOR0,
431 				   0);
432 	if (error)
433 		return;
434 
435 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
436 				   CPCAP_BIT_ADTRIG_DIS,
437 				   CPCAP_BIT_ADTRIG_DIS);
438 	if (error)
439 		return;
440 
441 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
442 				   CPCAP_BIT_ASC,
443 				   CPCAP_BIT_ASC);
444 	if (error)
445 		return;
446 
447 	do {
448 		schedule_timeout_uninterruptible(1);
449 		error = regmap_read(ddata->reg, CPCAP_REG_ADCC2, &value);
450 		if (error)
451 			return;
452 	} while ((value & CPCAP_BIT_ASC) && time_before(jiffies, timeout));
453 
454 	if (value & CPCAP_BIT_ASC)
455 		dev_err(ddata->dev,
456 			"Timeout waiting for calibration to complete\n");
457 
458 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
459 				   CPCAP_BIT_CAL_MODE, 0);
460 	if (error)
461 		return;
462 }
463 
cpcap_adc_calibrate_one(struct cpcap_adc * ddata,int channel,u16 calibration_register,int lower_threshold,int upper_threshold)464 static int cpcap_adc_calibrate_one(struct cpcap_adc *ddata,
465 				   int channel,
466 				   u16 calibration_register,
467 				   int lower_threshold,
468 				   int upper_threshold)
469 {
470 	unsigned int calibration_data[2];
471 	unsigned short cal_data_diff;
472 	int i, error;
473 
474 	for (i = 0; i < CPCAP_ADC_MAX_RETRIES; i++) {
475 		calibration_data[0]  = 0;
476 		calibration_data[1]  = 0;
477 		cal_data_diff = 0;
478 		cpcap_adc_setup_calibrate(ddata, channel);
479 		error = regmap_read(ddata->reg, calibration_register,
480 				    &calibration_data[0]);
481 		if (error)
482 			return error;
483 		cpcap_adc_setup_calibrate(ddata, channel);
484 		error = regmap_read(ddata->reg, calibration_register,
485 				    &calibration_data[1]);
486 		if (error)
487 			return error;
488 
489 		if (calibration_data[0] > calibration_data[1])
490 			cal_data_diff =
491 				calibration_data[0] - calibration_data[1];
492 		else
493 			cal_data_diff =
494 				calibration_data[1] - calibration_data[0];
495 
496 		if (((calibration_data[1] >= lower_threshold) &&
497 		     (calibration_data[1] <= upper_threshold) &&
498 		     (cal_data_diff <= ST_ADC_CALIBRATE_DIFF_THRESHOLD)) ||
499 		    (ddata->vendor == CPCAP_VENDOR_TI)) {
500 			bank_conversion[channel].cal_offset =
501 				((short)calibration_data[1] * -1) + 512;
502 			dev_dbg(ddata->dev, "ch%i calibration complete: %i\n",
503 				channel, bank_conversion[channel].cal_offset);
504 			break;
505 		}
506 		usleep_range(5000, 10000);
507 	}
508 
509 	return 0;
510 }
511 
cpcap_adc_calibrate(struct cpcap_adc * ddata)512 static int cpcap_adc_calibrate(struct cpcap_adc *ddata)
513 {
514 	int error;
515 
516 	error = cpcap_adc_calibrate_one(ddata, CPCAP_ADC_CHG_ISENSE,
517 					CPCAP_REG_ADCAL1,
518 					ST_ADC_CAL_CHRGI_LOW_THRESHOLD,
519 					ST_ADC_CAL_CHRGI_HIGH_THRESHOLD);
520 	if (error)
521 		return error;
522 
523 	error = cpcap_adc_calibrate_one(ddata, CPCAP_ADC_BATTI,
524 					CPCAP_REG_ADCAL2,
525 					ST_ADC_CAL_BATTI_LOW_THRESHOLD,
526 					ST_ADC_CAL_BATTI_HIGH_THRESHOLD);
527 	if (error)
528 		return error;
529 
530 	return 0;
531 }
532 
533 /* ADC setup, read and scale functions */
cpcap_adc_setup_bank(struct cpcap_adc * ddata,struct cpcap_adc_request * req)534 static void cpcap_adc_setup_bank(struct cpcap_adc *ddata,
535 				 struct cpcap_adc_request *req)
536 {
537 	const struct cpcap_adc_ato *ato = ddata->ato;
538 	unsigned short value1 = 0;
539 	unsigned short value2 = 0;
540 	int error;
541 
542 	if (!ato)
543 		return;
544 
545 	switch (req->channel) {
546 	case CPCAP_ADC_AD0:
547 		value2 |= CPCAP_BIT_THERMBIAS_EN;
548 		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
549 					   CPCAP_BIT_THERMBIAS_EN,
550 					   value2);
551 		if (error)
552 			return;
553 		usleep_range(800, 1000);
554 		break;
555 	case CPCAP_ADC_AD8 ... CPCAP_ADC_TSY2_AD15:
556 		value1 |= CPCAP_BIT_AD_SEL1;
557 		break;
558 	case CPCAP_ADC_BATTP_PI16 ... CPCAP_ADC_BATTI_PI17:
559 		value1 |= CPCAP_BIT_RAND1;
560 	default:
561 		break;
562 	}
563 
564 	switch (req->timing) {
565 	case CPCAP_ADC_TIMING_IN:
566 		value1 |= ato->ato_in;
567 		value1 |= ato->atox_in;
568 		value2 |= ato->adc_ps_factor_in;
569 		value2 |= ato->atox_ps_factor_in;
570 		break;
571 	case CPCAP_ADC_TIMING_OUT:
572 		value1 |= ato->ato_out;
573 		value1 |= ato->atox_out;
574 		value2 |= ato->adc_ps_factor_out;
575 		value2 |= ato->atox_ps_factor_out;
576 		break;
577 
578 	case CPCAP_ADC_TIMING_IMM:
579 	default:
580 		break;
581 	}
582 
583 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
584 				   CPCAP_BIT_CAL_MODE | CPCAP_BIT_ATOX |
585 				   CPCAP_BIT_ATO3 | CPCAP_BIT_ATO2 |
586 				   CPCAP_BIT_ATO1 | CPCAP_BIT_ATO0 |
587 				   CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 |
588 				   CPCAP_BIT_ADA0 | CPCAP_BIT_AD_SEL1 |
589 				   CPCAP_BIT_RAND1 | CPCAP_BIT_RAND0,
590 				   value1);
591 	if (error)
592 		return;
593 
594 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
595 				   CPCAP_BIT_ATOX_PS_FACTOR |
596 				   CPCAP_BIT_ADC_PS_FACTOR1 |
597 				   CPCAP_BIT_ADC_PS_FACTOR0 |
598 				   CPCAP_BIT_THERMBIAS_EN,
599 				   value2);
600 	if (error)
601 		return;
602 
603 	if (req->timing == CPCAP_ADC_TIMING_IMM) {
604 		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
605 					   CPCAP_BIT_ADTRIG_DIS,
606 					   CPCAP_BIT_ADTRIG_DIS);
607 		if (error)
608 			return;
609 
610 		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
611 					   CPCAP_BIT_ASC,
612 					   CPCAP_BIT_ASC);
613 		if (error)
614 			return;
615 	} else {
616 		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
617 					   CPCAP_BIT_ADTRIG_ONESHOT,
618 					   CPCAP_BIT_ADTRIG_ONESHOT);
619 		if (error)
620 			return;
621 
622 		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
623 					   CPCAP_BIT_ADTRIG_DIS, 0);
624 		if (error)
625 			return;
626 	}
627 }
628 
cpcap_adc_start_bank(struct cpcap_adc * ddata,struct cpcap_adc_request * req)629 static int cpcap_adc_start_bank(struct cpcap_adc *ddata,
630 				struct cpcap_adc_request *req)
631 {
632 	int i, error;
633 
634 	req->timing = CPCAP_ADC_TIMING_IMM;
635 	ddata->done = false;
636 
637 	for (i = 0; i < CPCAP_ADC_MAX_RETRIES; i++) {
638 		cpcap_adc_setup_bank(ddata, req);
639 		error = wait_event_interruptible_timeout(ddata->wq_data_avail,
640 							 ddata->done,
641 							 msecs_to_jiffies(50));
642 		if (error > 0)
643 			return 0;
644 
645 		if (error == 0) {
646 			error = -ETIMEDOUT;
647 			continue;
648 		}
649 
650 		if (error < 0)
651 			return error;
652 	}
653 
654 	return error;
655 }
656 
cpcap_adc_stop_bank(struct cpcap_adc * ddata)657 static int cpcap_adc_stop_bank(struct cpcap_adc *ddata)
658 {
659 	int error;
660 
661 	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
662 				   0xffff,
663 				   CPCAP_REG_ADCC1_DEFAULTS);
664 	if (error)
665 		return error;
666 
667 	return regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
668 				  0xffff,
669 				  CPCAP_REG_ADCC2_DEFAULTS);
670 }
671 
cpcap_adc_phase(struct cpcap_adc_request * req)672 static void cpcap_adc_phase(struct cpcap_adc_request *req)
673 {
674 	const struct cpcap_adc_conversion_tbl *conv_tbl = req->conv_tbl;
675 	const struct cpcap_adc_phasing_tbl *phase_tbl = req->phase_tbl;
676 	int index = req->channel;
677 
678 	/* Remuxed channels 16 and 17 use BATTP and BATTI entries */
679 	switch (req->channel) {
680 	case CPCAP_ADC_BATTP:
681 	case CPCAP_ADC_BATTP_PI16:
682 		index = req->bank_index;
683 		req->result -= phase_tbl[index].offset;
684 		req->result -= CPCAP_FOUR_POINT_TWO_ADC;
685 		req->result *= phase_tbl[index].multiplier;
686 		if (phase_tbl[index].divider == 0)
687 			return;
688 		req->result /= phase_tbl[index].divider;
689 		req->result += CPCAP_FOUR_POINT_TWO_ADC;
690 		break;
691 	case CPCAP_ADC_BATTI_PI17:
692 		index = req->bank_index;
693 		fallthrough;
694 	default:
695 		req->result += conv_tbl[index].cal_offset;
696 		req->result += conv_tbl[index].align_offset;
697 		req->result *= phase_tbl[index].multiplier;
698 		if (phase_tbl[index].divider == 0)
699 			return;
700 		req->result /= phase_tbl[index].divider;
701 		req->result += phase_tbl[index].offset;
702 		break;
703 	}
704 
705 	if (req->result < phase_tbl[index].min)
706 		req->result = phase_tbl[index].min;
707 	else if (req->result > phase_tbl[index].max)
708 		req->result = phase_tbl[index].max;
709 }
710 
711 /* Looks up temperatures in a table and calculates averages if needed */
cpcap_adc_table_to_millicelcius(unsigned short value)712 static int cpcap_adc_table_to_millicelcius(unsigned short value)
713 {
714 	int i, result = 0, alpha;
715 
716 	if (value <= temp_map[CPCAP_MAX_TEMP_LVL - 1][0])
717 		return temp_map[CPCAP_MAX_TEMP_LVL - 1][1];
718 
719 	if (value >= temp_map[0][0])
720 		return temp_map[0][1];
721 
722 	for (i = 0; i < CPCAP_MAX_TEMP_LVL - 1; i++) {
723 		if ((value <= temp_map[i][0]) &&
724 		    (value >= temp_map[i + 1][0])) {
725 			if (value == temp_map[i][0]) {
726 				result = temp_map[i][1];
727 			} else if (value == temp_map[i + 1][0]) {
728 				result = temp_map[i + 1][1];
729 			} else {
730 				alpha = ((value - temp_map[i][0]) * 1000) /
731 					(temp_map[i + 1][0] - temp_map[i][0]);
732 
733 				result = temp_map[i][1] +
734 					((alpha * (temp_map[i + 1][1] -
735 						 temp_map[i][1])) / 1000);
736 			}
737 			break;
738 		}
739 	}
740 
741 	return result;
742 }
743 
cpcap_adc_convert(struct cpcap_adc_request * req)744 static void cpcap_adc_convert(struct cpcap_adc_request *req)
745 {
746 	const struct cpcap_adc_conversion_tbl *conv_tbl = req->conv_tbl;
747 	int index = req->channel;
748 
749 	/* Remuxed channels 16 and 17 use BATTP and BATTI entries */
750 	switch (req->channel) {
751 	case CPCAP_ADC_BATTP_PI16:
752 		index = CPCAP_ADC_BATTP;
753 		break;
754 	case CPCAP_ADC_BATTI_PI17:
755 		index = CPCAP_ADC_BATTI;
756 		break;
757 	default:
758 		break;
759 	}
760 
761 	/* No conversion for raw channels */
762 	if (conv_tbl[index].conv_type == IIO_CHAN_INFO_RAW)
763 		return;
764 
765 	/* Temperatures use a lookup table instead of conversion table */
766 	if ((req->channel == CPCAP_ADC_AD0) ||
767 	    (req->channel == CPCAP_ADC_AD3)) {
768 		req->result =
769 			cpcap_adc_table_to_millicelcius(req->result);
770 
771 		return;
772 	}
773 
774 	/* All processed channels use a conversion table */
775 	req->result *= conv_tbl[index].multiplier;
776 	if (conv_tbl[index].divider == 0)
777 		return;
778 	req->result /= conv_tbl[index].divider;
779 	req->result += conv_tbl[index].conv_offset;
780 }
781 
782 /*
783  * REVISIT: Check if timed sampling can use multiple channels at the
784  * same time. If not, replace channel_mask with just channel.
785  */
cpcap_adc_read_bank_scaled(struct cpcap_adc * ddata,struct cpcap_adc_request * req)786 static int cpcap_adc_read_bank_scaled(struct cpcap_adc *ddata,
787 				      struct cpcap_adc_request *req)
788 {
789 	int calibration_data, error, addr;
790 
791 	if (ddata->vendor == CPCAP_VENDOR_TI) {
792 		error = regmap_read(ddata->reg, CPCAP_REG_ADCAL1,
793 				    &calibration_data);
794 		if (error)
795 			return error;
796 		bank_conversion[CPCAP_ADC_CHG_ISENSE].cal_offset =
797 			((short)calibration_data * -1) + 512;
798 
799 		error = regmap_read(ddata->reg, CPCAP_REG_ADCAL2,
800 				    &calibration_data);
801 		if (error)
802 			return error;
803 		bank_conversion[CPCAP_ADC_BATTI].cal_offset =
804 			((short)calibration_data * -1) + 512;
805 	}
806 
807 	addr = CPCAP_REG_ADCD0 + req->bank_index * 4;
808 
809 	error = regmap_read(ddata->reg, addr, &req->result);
810 	if (error)
811 		return error;
812 
813 	req->result &= 0x3ff;
814 	cpcap_adc_phase(req);
815 	cpcap_adc_convert(req);
816 
817 	return 0;
818 }
819 
cpcap_adc_init_request(struct cpcap_adc_request * req,int channel)820 static int cpcap_adc_init_request(struct cpcap_adc_request *req,
821 				  int channel)
822 {
823 	req->channel = channel;
824 	req->phase_tbl = bank_phasing;
825 	req->conv_tbl = bank_conversion;
826 
827 	switch (channel) {
828 	case CPCAP_ADC_AD0 ... CPCAP_ADC_USB_ID:
829 		req->bank_index = channel;
830 		break;
831 	case CPCAP_ADC_AD8 ... CPCAP_ADC_TSY2_AD15:
832 		req->bank_index = channel - 8;
833 		break;
834 	case CPCAP_ADC_BATTP_PI16:
835 		req->bank_index = CPCAP_ADC_BATTP;
836 		break;
837 	case CPCAP_ADC_BATTI_PI17:
838 		req->bank_index = CPCAP_ADC_BATTI;
839 		break;
840 	default:
841 		return -EINVAL;
842 	}
843 
844 	return 0;
845 }
846 
cpcap_adc_read_st_die_temp(struct cpcap_adc * ddata,int addr,int * val)847 static int cpcap_adc_read_st_die_temp(struct cpcap_adc *ddata,
848 				      int addr, int *val)
849 {
850 	int error;
851 
852 	error = regmap_read(ddata->reg, addr, val);
853 	if (error)
854 		return error;
855 
856 	*val -= 282;
857 	*val *= 114;
858 	*val += 25000;
859 
860 	return 0;
861 }
862 
cpcap_adc_read(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)863 static int cpcap_adc_read(struct iio_dev *indio_dev,
864 			  struct iio_chan_spec const *chan,
865 			  int *val, int *val2, long mask)
866 {
867 	struct cpcap_adc *ddata = iio_priv(indio_dev);
868 	struct cpcap_adc_request req;
869 	int error;
870 
871 	error = cpcap_adc_init_request(&req, chan->channel);
872 	if (error)
873 		return error;
874 
875 	switch (mask) {
876 	case IIO_CHAN_INFO_RAW:
877 		mutex_lock(&ddata->lock);
878 		error = cpcap_adc_start_bank(ddata, &req);
879 		if (error)
880 			goto err_unlock;
881 		error = regmap_read(ddata->reg, chan->address, val);
882 		if (error)
883 			goto err_unlock;
884 		error = cpcap_adc_stop_bank(ddata);
885 		if (error)
886 			goto err_unlock;
887 		mutex_unlock(&ddata->lock);
888 		break;
889 	case IIO_CHAN_INFO_PROCESSED:
890 		mutex_lock(&ddata->lock);
891 		error = cpcap_adc_start_bank(ddata, &req);
892 		if (error)
893 			goto err_unlock;
894 		if ((ddata->vendor == CPCAP_VENDOR_ST) &&
895 		    (chan->channel == CPCAP_ADC_AD3)) {
896 			error = cpcap_adc_read_st_die_temp(ddata,
897 							   chan->address,
898 							   &req.result);
899 			if (error)
900 				goto err_unlock;
901 		} else {
902 			error = cpcap_adc_read_bank_scaled(ddata, &req);
903 			if (error)
904 				goto err_unlock;
905 		}
906 		error = cpcap_adc_stop_bank(ddata);
907 		if (error)
908 			goto err_unlock;
909 		mutex_unlock(&ddata->lock);
910 		*val = req.result;
911 		break;
912 	default:
913 		return -EINVAL;
914 	}
915 
916 	return IIO_VAL_INT;
917 
918 err_unlock:
919 	mutex_unlock(&ddata->lock);
920 	dev_err(ddata->dev, "error reading ADC: %i\n", error);
921 
922 	return error;
923 }
924 
925 static const struct iio_info cpcap_adc_info = {
926 	.read_raw = &cpcap_adc_read,
927 };
928 
929 /*
930  * Configuration for Motorola mapphone series such as droid 4.
931  * Copied from the Motorola mapphone kernel tree.
932  */
933 static const struct cpcap_adc_ato mapphone_adc = {
934 	.ato_in = 0x0480,
935 	.atox_in = 0,
936 	.adc_ps_factor_in = 0x0200,
937 	.atox_ps_factor_in = 0,
938 	.ato_out = 0,
939 	.atox_out = 0,
940 	.adc_ps_factor_out = 0,
941 	.atox_ps_factor_out = 0,
942 };
943 
944 static const struct of_device_id cpcap_adc_id_table[] = {
945 	{
946 		.compatible = "motorola,cpcap-adc",
947 	},
948 	{
949 		.compatible = "motorola,mapphone-cpcap-adc",
950 		.data = &mapphone_adc,
951 	},
952 	{ /* sentinel */ },
953 };
954 MODULE_DEVICE_TABLE(of, cpcap_adc_id_table);
955 
cpcap_adc_probe(struct platform_device * pdev)956 static int cpcap_adc_probe(struct platform_device *pdev)
957 {
958 	struct cpcap_adc *ddata;
959 	struct iio_dev *indio_dev;
960 	int error;
961 
962 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*ddata));
963 	if (!indio_dev) {
964 		dev_err(&pdev->dev, "failed to allocate iio device\n");
965 
966 		return -ENOMEM;
967 	}
968 	ddata = iio_priv(indio_dev);
969 	ddata->ato = device_get_match_data(&pdev->dev);
970 	if (!ddata->ato)
971 		return -ENODEV;
972 	ddata->dev = &pdev->dev;
973 
974 	mutex_init(&ddata->lock);
975 	init_waitqueue_head(&ddata->wq_data_avail);
976 
977 	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
978 	indio_dev->channels = cpcap_adc_channels;
979 	indio_dev->num_channels = ARRAY_SIZE(cpcap_adc_channels);
980 	indio_dev->name = dev_name(&pdev->dev);
981 	indio_dev->info = &cpcap_adc_info;
982 
983 	ddata->reg = dev_get_regmap(pdev->dev.parent, NULL);
984 	if (!ddata->reg)
985 		return -ENODEV;
986 
987 	error = cpcap_get_vendor(ddata->dev, ddata->reg, &ddata->vendor);
988 	if (error)
989 		return error;
990 
991 	platform_set_drvdata(pdev, indio_dev);
992 
993 	ddata->irq = platform_get_irq_byname(pdev, "adcdone");
994 	if (ddata->irq < 0)
995 		return -ENODEV;
996 
997 	error = devm_request_threaded_irq(&pdev->dev, ddata->irq, NULL,
998 					  cpcap_adc_irq_thread,
999 					  IRQF_TRIGGER_NONE | IRQF_ONESHOT,
1000 					  "cpcap-adc", indio_dev);
1001 	if (error) {
1002 		dev_err(&pdev->dev, "could not get irq: %i\n",
1003 			error);
1004 
1005 		return error;
1006 	}
1007 
1008 	error = cpcap_adc_calibrate(ddata);
1009 	if (error)
1010 		return error;
1011 
1012 	dev_info(&pdev->dev, "CPCAP ADC device probed\n");
1013 
1014 	return devm_iio_device_register(&pdev->dev, indio_dev);
1015 }
1016 
1017 static struct platform_driver cpcap_adc_driver = {
1018 	.driver = {
1019 		.name = "cpcap_adc",
1020 		.of_match_table = cpcap_adc_id_table,
1021 	},
1022 	.probe = cpcap_adc_probe,
1023 };
1024 
1025 module_platform_driver(cpcap_adc_driver);
1026 
1027 MODULE_ALIAS("platform:cpcap_adc");
1028 MODULE_DESCRIPTION("CPCAP ADC driver");
1029 MODULE_AUTHOR("Tony Lindgren <tony@atomide.com");
1030 MODULE_LICENSE("GPL v2");
1031