xref: /openbmc/linux/drivers/iio/adc/sc27xx_adc.c (revision 2a598d0b)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Spreadtrum Communications Inc.
3 
4 #include <linux/hwspinlock.h>
5 #include <linux/iio/iio.h>
6 #include <linux/module.h>
7 #include <linux/mutex.h>
8 #include <linux/nvmem-consumer.h>
9 #include <linux/of.h>
10 #include <linux/of_device.h>
11 #include <linux/platform_device.h>
12 #include <linux/regmap.h>
13 #include <linux/regulator/consumer.h>
14 #include <linux/slab.h>
15 
16 /* PMIC global registers definition */
17 #define SC2730_MODULE_EN		0x1808
18 #define SC2731_MODULE_EN		0xc08
19 #define SC27XX_MODULE_ADC_EN		BIT(5)
20 #define SC2721_ARM_CLK_EN		0xc0c
21 #define SC2730_ARM_CLK_EN		0x180c
22 #define SC2731_ARM_CLK_EN		0xc10
23 #define SC27XX_CLK_ADC_EN		BIT(5)
24 #define SC27XX_CLK_ADC_CLK_EN		BIT(6)
25 
26 /* ADC controller registers definition */
27 #define SC27XX_ADC_CTL			0x0
28 #define SC27XX_ADC_CH_CFG		0x4
29 #define SC27XX_ADC_DATA			0x4c
30 #define SC27XX_ADC_INT_EN		0x50
31 #define SC27XX_ADC_INT_CLR		0x54
32 #define SC27XX_ADC_INT_STS		0x58
33 #define SC27XX_ADC_INT_RAW		0x5c
34 
35 /* Bits and mask definition for SC27XX_ADC_CTL register */
36 #define SC27XX_ADC_EN			BIT(0)
37 #define SC27XX_ADC_CHN_RUN		BIT(1)
38 #define SC27XX_ADC_12BIT_MODE		BIT(2)
39 #define SC27XX_ADC_RUN_NUM_MASK		GENMASK(7, 4)
40 #define SC27XX_ADC_RUN_NUM_SHIFT	4
41 
42 /* Bits and mask definition for SC27XX_ADC_CH_CFG register */
43 #define SC27XX_ADC_CHN_ID_MASK		GENMASK(4, 0)
44 #define SC27XX_ADC_SCALE_MASK		GENMASK(10, 9)
45 #define SC2721_ADC_SCALE_MASK		BIT(5)
46 #define SC27XX_ADC_SCALE_SHIFT		9
47 #define SC2721_ADC_SCALE_SHIFT		5
48 
49 /* Bits definitions for SC27XX_ADC_INT_EN registers */
50 #define SC27XX_ADC_IRQ_EN		BIT(0)
51 
52 /* Bits definitions for SC27XX_ADC_INT_CLR registers */
53 #define SC27XX_ADC_IRQ_CLR		BIT(0)
54 
55 /* Bits definitions for SC27XX_ADC_INT_RAW registers */
56 #define SC27XX_ADC_IRQ_RAW		BIT(0)
57 
58 /* Mask definition for SC27XX_ADC_DATA register */
59 #define SC27XX_ADC_DATA_MASK		GENMASK(11, 0)
60 
61 /* Timeout (ms) for the trylock of hardware spinlocks */
62 #define SC27XX_ADC_HWLOCK_TIMEOUT	5000
63 
64 /* Timeout (us) for ADC data conversion according to ADC datasheet */
65 #define SC27XX_ADC_RDY_TIMEOUT		1000000
66 #define SC27XX_ADC_POLL_RAW_STATUS	500
67 
68 /* Maximum ADC channel number */
69 #define SC27XX_ADC_CHANNEL_MAX		32
70 
71 /* ADC voltage ratio definition */
72 #define SC27XX_VOLT_RATIO(n, d)		\
73 	(((n) << SC27XX_RATIO_NUMERATOR_OFFSET) | (d))
74 #define SC27XX_RATIO_NUMERATOR_OFFSET	16
75 #define SC27XX_RATIO_DENOMINATOR_MASK	GENMASK(15, 0)
76 
77 /* ADC specific channel reference voltage 3.5V */
78 #define SC27XX_ADC_REFVOL_VDD35		3500000
79 
80 /* ADC default channel reference voltage is 2.8V */
81 #define SC27XX_ADC_REFVOL_VDD28		2800000
82 
83 struct sc27xx_adc_data {
84 	struct device *dev;
85 	struct regulator *volref;
86 	struct regmap *regmap;
87 	/* lock to protect against multiple access to the device */
88 	struct mutex lock;
89 	/*
90 	 * One hardware spinlock to synchronize between the multiple
91 	 * subsystems which will access the unique ADC controller.
92 	 */
93 	struct hwspinlock *hwlock;
94 	int channel_scale[SC27XX_ADC_CHANNEL_MAX];
95 	u32 base;
96 	int irq;
97 	const struct sc27xx_adc_variant_data *var_data;
98 };
99 
100 /*
101  * Since different PMICs of SC27xx series can have different
102  * address and ratio, we should save ratio config and base
103  * in the device data structure.
104  */
105 struct sc27xx_adc_variant_data {
106 	u32 module_en;
107 	u32 clk_en;
108 	u32 scale_shift;
109 	u32 scale_mask;
110 	const struct sc27xx_adc_linear_graph *bscale_cal;
111 	const struct sc27xx_adc_linear_graph *sscale_cal;
112 	void (*init_scale)(struct sc27xx_adc_data *data);
113 	int (*get_ratio)(int channel, int scale);
114 	bool set_volref;
115 };
116 
117 struct sc27xx_adc_linear_graph {
118 	int volt0;
119 	int adc0;
120 	int volt1;
121 	int adc1;
122 };
123 
124 /*
125  * According to the datasheet, we can convert one ADC value to one voltage value
126  * through 2 points in the linear graph. If the voltage is less than 1.2v, we
127  * should use the small-scale graph, and if more than 1.2v, we should use the
128  * big-scale graph.
129  */
130 static struct sc27xx_adc_linear_graph big_scale_graph = {
131 	4200, 3310,
132 	3600, 2832,
133 };
134 
135 static struct sc27xx_adc_linear_graph small_scale_graph = {
136 	1000, 3413,
137 	100, 341,
138 };
139 
140 static const struct sc27xx_adc_linear_graph sc2731_big_scale_graph_calib = {
141 	4200, 850,
142 	3600, 728,
143 };
144 
145 static const struct sc27xx_adc_linear_graph sc2731_small_scale_graph_calib = {
146 	1000, 838,
147 	100, 84,
148 };
149 
150 static const struct sc27xx_adc_linear_graph big_scale_graph_calib = {
151 	4200, 856,
152 	3600, 733,
153 };
154 
155 static const struct sc27xx_adc_linear_graph small_scale_graph_calib = {
156 	1000, 833,
157 	100, 80,
158 };
159 
160 static int sc27xx_adc_get_calib_data(u32 calib_data, int calib_adc)
161 {
162 	return ((calib_data & 0xff) + calib_adc - 128) * 4;
163 }
164 
165 /* get the adc nvmem cell calibration data */
166 static int adc_nvmem_cell_calib_data(struct sc27xx_adc_data *data, const char *cell_name)
167 {
168 	struct nvmem_cell *cell;
169 	void *buf;
170 	u32 origin_calib_data = 0;
171 	size_t len;
172 
173 	if (!data)
174 		return -EINVAL;
175 
176 	cell = nvmem_cell_get(data->dev, cell_name);
177 	if (IS_ERR(cell))
178 		return PTR_ERR(cell);
179 
180 	buf = nvmem_cell_read(cell, &len);
181 	if (IS_ERR(buf)) {
182 		nvmem_cell_put(cell);
183 		return PTR_ERR(buf);
184 	}
185 
186 	memcpy(&origin_calib_data, buf, min(len, sizeof(u32)));
187 
188 	kfree(buf);
189 	nvmem_cell_put(cell);
190 	return origin_calib_data;
191 }
192 
193 static int sc27xx_adc_scale_calibration(struct sc27xx_adc_data *data,
194 					bool big_scale)
195 {
196 	const struct sc27xx_adc_linear_graph *calib_graph;
197 	struct sc27xx_adc_linear_graph *graph;
198 	const char *cell_name;
199 	u32 calib_data = 0;
200 
201 	if (big_scale) {
202 		calib_graph = data->var_data->bscale_cal;
203 		graph = &big_scale_graph;
204 		cell_name = "big_scale_calib";
205 	} else {
206 		calib_graph = data->var_data->sscale_cal;
207 		graph = &small_scale_graph;
208 		cell_name = "small_scale_calib";
209 	}
210 
211 	calib_data = adc_nvmem_cell_calib_data(data, cell_name);
212 
213 	/* Only need to calibrate the adc values in the linear graph. */
214 	graph->adc0 = sc27xx_adc_get_calib_data(calib_data, calib_graph->adc0);
215 	graph->adc1 = sc27xx_adc_get_calib_data(calib_data >> 8,
216 						calib_graph->adc1);
217 
218 	return 0;
219 }
220 
221 static int sc2720_adc_get_ratio(int channel, int scale)
222 {
223 	switch (channel) {
224 	case 14:
225 		switch (scale) {
226 		case 0:
227 			return SC27XX_VOLT_RATIO(68, 900);
228 		case 1:
229 			return SC27XX_VOLT_RATIO(68, 1760);
230 		case 2:
231 			return SC27XX_VOLT_RATIO(68, 2327);
232 		case 3:
233 			return SC27XX_VOLT_RATIO(68, 3654);
234 		default:
235 			return SC27XX_VOLT_RATIO(1, 1);
236 		}
237 	case 16:
238 		switch (scale) {
239 		case 0:
240 			return SC27XX_VOLT_RATIO(48, 100);
241 		case 1:
242 			return SC27XX_VOLT_RATIO(480, 1955);
243 		case 2:
244 			return SC27XX_VOLT_RATIO(480, 2586);
245 		case 3:
246 			return SC27XX_VOLT_RATIO(48, 406);
247 		default:
248 			return SC27XX_VOLT_RATIO(1, 1);
249 		}
250 	case 21:
251 	case 22:
252 	case 23:
253 		switch (scale) {
254 		case 0:
255 			return SC27XX_VOLT_RATIO(3, 8);
256 		case 1:
257 			return SC27XX_VOLT_RATIO(375, 1955);
258 		case 2:
259 			return SC27XX_VOLT_RATIO(375, 2586);
260 		case 3:
261 			return SC27XX_VOLT_RATIO(300, 3248);
262 		default:
263 			return SC27XX_VOLT_RATIO(1, 1);
264 		}
265 	default:
266 		switch (scale) {
267 		case 0:
268 			return SC27XX_VOLT_RATIO(1, 1);
269 		case 1:
270 			return SC27XX_VOLT_RATIO(1000, 1955);
271 		case 2:
272 			return SC27XX_VOLT_RATIO(1000, 2586);
273 		case 3:
274 			return SC27XX_VOLT_RATIO(100, 406);
275 		default:
276 			return SC27XX_VOLT_RATIO(1, 1);
277 		}
278 	}
279 	return SC27XX_VOLT_RATIO(1, 1);
280 }
281 
282 static int sc2721_adc_get_ratio(int channel, int scale)
283 {
284 	switch (channel) {
285 	case 1:
286 	case 2:
287 	case 3:
288 	case 4:
289 		return scale ? SC27XX_VOLT_RATIO(400, 1025) :
290 			SC27XX_VOLT_RATIO(1, 1);
291 	case 5:
292 		return SC27XX_VOLT_RATIO(7, 29);
293 	case 7:
294 	case 9:
295 		return scale ? SC27XX_VOLT_RATIO(100, 125) :
296 			SC27XX_VOLT_RATIO(1, 1);
297 	case 14:
298 		return SC27XX_VOLT_RATIO(68, 900);
299 	case 16:
300 		return SC27XX_VOLT_RATIO(48, 100);
301 	case 19:
302 		return SC27XX_VOLT_RATIO(1, 3);
303 	default:
304 		return SC27XX_VOLT_RATIO(1, 1);
305 	}
306 	return SC27XX_VOLT_RATIO(1, 1);
307 }
308 
309 static int sc2730_adc_get_ratio(int channel, int scale)
310 {
311 	switch (channel) {
312 	case 14:
313 		switch (scale) {
314 		case 0:
315 			return SC27XX_VOLT_RATIO(68, 900);
316 		case 1:
317 			return SC27XX_VOLT_RATIO(68, 1760);
318 		case 2:
319 			return SC27XX_VOLT_RATIO(68, 2327);
320 		case 3:
321 			return SC27XX_VOLT_RATIO(68, 3654);
322 		default:
323 			return SC27XX_VOLT_RATIO(1, 1);
324 		}
325 	case 15:
326 		switch (scale) {
327 		case 0:
328 			return SC27XX_VOLT_RATIO(1, 3);
329 		case 1:
330 			return SC27XX_VOLT_RATIO(1000, 5865);
331 		case 2:
332 			return SC27XX_VOLT_RATIO(500, 3879);
333 		case 3:
334 			return SC27XX_VOLT_RATIO(500, 6090);
335 		default:
336 			return SC27XX_VOLT_RATIO(1, 1);
337 		}
338 	case 16:
339 		switch (scale) {
340 		case 0:
341 			return SC27XX_VOLT_RATIO(48, 100);
342 		case 1:
343 			return SC27XX_VOLT_RATIO(480, 1955);
344 		case 2:
345 			return SC27XX_VOLT_RATIO(480, 2586);
346 		case 3:
347 			return SC27XX_VOLT_RATIO(48, 406);
348 		default:
349 			return SC27XX_VOLT_RATIO(1, 1);
350 		}
351 	case 21:
352 	case 22:
353 	case 23:
354 		switch (scale) {
355 		case 0:
356 			return SC27XX_VOLT_RATIO(3, 8);
357 		case 1:
358 			return SC27XX_VOLT_RATIO(375, 1955);
359 		case 2:
360 			return SC27XX_VOLT_RATIO(375, 2586);
361 		case 3:
362 			return SC27XX_VOLT_RATIO(300, 3248);
363 		default:
364 			return SC27XX_VOLT_RATIO(1, 1);
365 		}
366 	default:
367 		switch (scale) {
368 		case 0:
369 			return SC27XX_VOLT_RATIO(1, 1);
370 		case 1:
371 			return SC27XX_VOLT_RATIO(1000, 1955);
372 		case 2:
373 			return SC27XX_VOLT_RATIO(1000, 2586);
374 		case 3:
375 			return SC27XX_VOLT_RATIO(1000, 4060);
376 		default:
377 			return SC27XX_VOLT_RATIO(1, 1);
378 		}
379 	}
380 	return SC27XX_VOLT_RATIO(1, 1);
381 }
382 
383 static int sc2731_adc_get_ratio(int channel, int scale)
384 {
385 	switch (channel) {
386 	case 1:
387 	case 2:
388 	case 3:
389 	case 4:
390 		return scale ? SC27XX_VOLT_RATIO(400, 1025) :
391 			SC27XX_VOLT_RATIO(1, 1);
392 	case 5:
393 		return SC27XX_VOLT_RATIO(7, 29);
394 	case 6:
395 		return SC27XX_VOLT_RATIO(375, 9000);
396 	case 7:
397 	case 8:
398 		return scale ? SC27XX_VOLT_RATIO(100, 125) :
399 			SC27XX_VOLT_RATIO(1, 1);
400 	case 19:
401 		return SC27XX_VOLT_RATIO(1, 3);
402 	default:
403 		return SC27XX_VOLT_RATIO(1, 1);
404 	}
405 	return SC27XX_VOLT_RATIO(1, 1);
406 }
407 
408 /*
409  * According to the datasheet set specific value on some channel.
410  */
411 static void sc2720_adc_scale_init(struct sc27xx_adc_data *data)
412 {
413 	int i;
414 
415 	for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
416 		switch (i) {
417 		case 5:
418 			data->channel_scale[i] = 3;
419 			break;
420 		case 7:
421 		case 9:
422 			data->channel_scale[i] = 2;
423 			break;
424 		case 13:
425 			data->channel_scale[i] = 1;
426 			break;
427 		case 19:
428 		case 30:
429 		case 31:
430 			data->channel_scale[i] = 3;
431 			break;
432 		default:
433 			data->channel_scale[i] = 0;
434 			break;
435 		}
436 	}
437 }
438 
439 static void sc2730_adc_scale_init(struct sc27xx_adc_data *data)
440 {
441 	int i;
442 
443 	for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
444 		switch (i) {
445 		case 5:
446 		case 10:
447 		case 19:
448 		case 30:
449 		case 31:
450 			data->channel_scale[i] = 3;
451 			break;
452 		case 7:
453 		case 9:
454 			data->channel_scale[i] = 2;
455 			break;
456 		case 13:
457 			data->channel_scale[i] = 1;
458 			break;
459 		default:
460 			data->channel_scale[i] = 0;
461 			break;
462 		}
463 	}
464 }
465 
466 static void sc2731_adc_scale_init(struct sc27xx_adc_data *data)
467 {
468 	int i;
469 	/*
470 	 * In the current software design, SC2731 support 2 scales,
471 	 * channels 5 uses big scale, others use smale.
472 	 */
473 	for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
474 		switch (i) {
475 		case 5:
476 			data->channel_scale[i] = 1;
477 			break;
478 		default:
479 			data->channel_scale[i] = 0;
480 			break;
481 		}
482 	}
483 }
484 
485 static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel,
486 			   int scale, int *val)
487 {
488 	int ret, ret_volref;
489 	u32 tmp, value, status;
490 
491 	ret = hwspin_lock_timeout_raw(data->hwlock, SC27XX_ADC_HWLOCK_TIMEOUT);
492 	if (ret) {
493 		dev_err(data->dev, "timeout to get the hwspinlock\n");
494 		return ret;
495 	}
496 
497 	/*
498 	 * According to the sc2721 chip data sheet, the reference voltage of
499 	 * specific channel 30 and channel 31 in ADC module needs to be set from
500 	 * the default 2.8v to 3.5v.
501 	 */
502 	if ((data->var_data->set_volref) && (channel == 30 || channel == 31)) {
503 		ret = regulator_set_voltage(data->volref,
504 					SC27XX_ADC_REFVOL_VDD35,
505 					SC27XX_ADC_REFVOL_VDD35);
506 		if (ret) {
507 			dev_err(data->dev, "failed to set the volref 3.5v\n");
508 			goto unlock_adc;
509 		}
510 	}
511 
512 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
513 				 SC27XX_ADC_EN, SC27XX_ADC_EN);
514 	if (ret)
515 		goto regulator_restore;
516 
517 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_CLR,
518 				 SC27XX_ADC_IRQ_CLR, SC27XX_ADC_IRQ_CLR);
519 	if (ret)
520 		goto disable_adc;
521 
522 	/* Configure the channel id and scale */
523 	tmp = (scale << data->var_data->scale_shift) & data->var_data->scale_mask;
524 	tmp |= channel & SC27XX_ADC_CHN_ID_MASK;
525 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CH_CFG,
526 				 SC27XX_ADC_CHN_ID_MASK |
527 				 data->var_data->scale_mask,
528 				 tmp);
529 	if (ret)
530 		goto disable_adc;
531 
532 	/* Select 12bit conversion mode, and only sample 1 time */
533 	tmp = SC27XX_ADC_12BIT_MODE;
534 	tmp |= (0 << SC27XX_ADC_RUN_NUM_SHIFT) & SC27XX_ADC_RUN_NUM_MASK;
535 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
536 				 SC27XX_ADC_RUN_NUM_MASK | SC27XX_ADC_12BIT_MODE,
537 				 tmp);
538 	if (ret)
539 		goto disable_adc;
540 
541 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
542 				 SC27XX_ADC_CHN_RUN, SC27XX_ADC_CHN_RUN);
543 	if (ret)
544 		goto disable_adc;
545 
546 	ret = regmap_read_poll_timeout(data->regmap,
547 				       data->base + SC27XX_ADC_INT_RAW,
548 				       status, (status & SC27XX_ADC_IRQ_RAW),
549 				       SC27XX_ADC_POLL_RAW_STATUS,
550 				       SC27XX_ADC_RDY_TIMEOUT);
551 	if (ret) {
552 		dev_err(data->dev, "read adc timeout, status = 0x%x\n", status);
553 		goto disable_adc;
554 	}
555 
556 	ret = regmap_read(data->regmap, data->base + SC27XX_ADC_DATA, &value);
557 	if (ret)
558 		goto disable_adc;
559 
560 	value &= SC27XX_ADC_DATA_MASK;
561 
562 disable_adc:
563 	regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
564 			   SC27XX_ADC_EN, 0);
565 regulator_restore:
566 	if ((data->var_data->set_volref) && (channel == 30 || channel == 31)) {
567 		ret_volref = regulator_set_voltage(data->volref,
568 					    SC27XX_ADC_REFVOL_VDD28,
569 					    SC27XX_ADC_REFVOL_VDD28);
570 		if (ret_volref) {
571 			dev_err(data->dev, "failed to set the volref 2.8v,ret_volref = 0x%x\n",
572 					 ret_volref);
573 			ret = ret || ret_volref;
574 		}
575 	}
576 unlock_adc:
577 	hwspin_unlock_raw(data->hwlock);
578 
579 	if (!ret)
580 		*val = value;
581 
582 	return ret;
583 }
584 
585 static void sc27xx_adc_volt_ratio(struct sc27xx_adc_data *data, int channel, int scale,
586 				  struct u32_fract *fract)
587 {
588 	u32 ratio;
589 
590 	ratio = data->var_data->get_ratio(channel, scale);
591 	fract->numerator = ratio >> SC27XX_RATIO_NUMERATOR_OFFSET;
592 	fract->denominator = ratio & SC27XX_RATIO_DENOMINATOR_MASK;
593 }
594 
595 static int adc_to_volt(struct sc27xx_adc_linear_graph *graph,
596 			      int raw_adc)
597 {
598 	int tmp;
599 
600 	tmp = (graph->volt0 - graph->volt1) * (raw_adc - graph->adc1);
601 	tmp /= (graph->adc0 - graph->adc1);
602 	tmp += graph->volt1;
603 
604 	return tmp;
605 }
606 
607 static int sc27xx_adc_to_volt(struct sc27xx_adc_linear_graph *graph,
608 			      int raw_adc)
609 {
610 	int tmp;
611 
612 	tmp = adc_to_volt(graph, raw_adc);
613 
614 	return tmp < 0 ? 0 : tmp;
615 }
616 
617 static int sc27xx_adc_convert_volt(struct sc27xx_adc_data *data, int channel,
618 				   int scale, int raw_adc)
619 {
620 	struct u32_fract fract;
621 	u32 volt;
622 
623 	/*
624 	 * Convert ADC values to voltage values according to the linear graph,
625 	 * and channel 5 and channel 1 has been calibrated, so we can just
626 	 * return the voltage values calculated by the linear graph. But other
627 	 * channels need be calculated to the real voltage values with the
628 	 * voltage ratio.
629 	 */
630 	switch (channel) {
631 	case 5:
632 		return sc27xx_adc_to_volt(&big_scale_graph, raw_adc);
633 
634 	case 1:
635 		return sc27xx_adc_to_volt(&small_scale_graph, raw_adc);
636 
637 	default:
638 		volt = sc27xx_adc_to_volt(&small_scale_graph, raw_adc);
639 		break;
640 	}
641 
642 	sc27xx_adc_volt_ratio(data, channel, scale, &fract);
643 
644 	return DIV_ROUND_CLOSEST(volt * fract.denominator, fract.numerator);
645 }
646 
647 static int sc27xx_adc_read_processed(struct sc27xx_adc_data *data,
648 				     int channel, int scale, int *val)
649 {
650 	int ret, raw_adc;
651 
652 	ret = sc27xx_adc_read(data, channel, scale, &raw_adc);
653 	if (ret)
654 		return ret;
655 
656 	*val = sc27xx_adc_convert_volt(data, channel, scale, raw_adc);
657 	return 0;
658 }
659 
660 static int sc27xx_adc_read_raw(struct iio_dev *indio_dev,
661 			       struct iio_chan_spec const *chan,
662 			       int *val, int *val2, long mask)
663 {
664 	struct sc27xx_adc_data *data = iio_priv(indio_dev);
665 	int scale = data->channel_scale[chan->channel];
666 	int ret, tmp;
667 
668 	switch (mask) {
669 	case IIO_CHAN_INFO_RAW:
670 		mutex_lock(&data->lock);
671 		ret = sc27xx_adc_read(data, chan->channel, scale, &tmp);
672 		mutex_unlock(&data->lock);
673 
674 		if (ret)
675 			return ret;
676 
677 		*val = tmp;
678 		return IIO_VAL_INT;
679 
680 	case IIO_CHAN_INFO_PROCESSED:
681 		mutex_lock(&data->lock);
682 		ret = sc27xx_adc_read_processed(data, chan->channel, scale,
683 						&tmp);
684 		mutex_unlock(&data->lock);
685 
686 		if (ret)
687 			return ret;
688 
689 		*val = tmp;
690 		return IIO_VAL_INT;
691 
692 	case IIO_CHAN_INFO_SCALE:
693 		*val = scale;
694 		return IIO_VAL_INT;
695 
696 	default:
697 		return -EINVAL;
698 	}
699 }
700 
701 static int sc27xx_adc_write_raw(struct iio_dev *indio_dev,
702 				struct iio_chan_spec const *chan,
703 				int val, int val2, long mask)
704 {
705 	struct sc27xx_adc_data *data = iio_priv(indio_dev);
706 
707 	switch (mask) {
708 	case IIO_CHAN_INFO_SCALE:
709 		data->channel_scale[chan->channel] = val;
710 		return IIO_VAL_INT;
711 
712 	default:
713 		return -EINVAL;
714 	}
715 }
716 
717 static const struct iio_info sc27xx_info = {
718 	.read_raw = &sc27xx_adc_read_raw,
719 	.write_raw = &sc27xx_adc_write_raw,
720 };
721 
722 #define SC27XX_ADC_CHANNEL(index, mask) {			\
723 	.type = IIO_VOLTAGE,					\
724 	.channel = index,					\
725 	.info_mask_separate = mask | BIT(IIO_CHAN_INFO_SCALE),	\
726 	.datasheet_name = "CH##index",				\
727 	.indexed = 1,						\
728 }
729 
730 static const struct iio_chan_spec sc27xx_channels[] = {
731 	SC27XX_ADC_CHANNEL(0, BIT(IIO_CHAN_INFO_PROCESSED)),
732 	SC27XX_ADC_CHANNEL(1, BIT(IIO_CHAN_INFO_PROCESSED)),
733 	SC27XX_ADC_CHANNEL(2, BIT(IIO_CHAN_INFO_PROCESSED)),
734 	SC27XX_ADC_CHANNEL(3, BIT(IIO_CHAN_INFO_PROCESSED)),
735 	SC27XX_ADC_CHANNEL(4, BIT(IIO_CHAN_INFO_PROCESSED)),
736 	SC27XX_ADC_CHANNEL(5, BIT(IIO_CHAN_INFO_PROCESSED)),
737 	SC27XX_ADC_CHANNEL(6, BIT(IIO_CHAN_INFO_PROCESSED)),
738 	SC27XX_ADC_CHANNEL(7, BIT(IIO_CHAN_INFO_PROCESSED)),
739 	SC27XX_ADC_CHANNEL(8, BIT(IIO_CHAN_INFO_PROCESSED)),
740 	SC27XX_ADC_CHANNEL(9, BIT(IIO_CHAN_INFO_PROCESSED)),
741 	SC27XX_ADC_CHANNEL(10, BIT(IIO_CHAN_INFO_PROCESSED)),
742 	SC27XX_ADC_CHANNEL(11, BIT(IIO_CHAN_INFO_PROCESSED)),
743 	SC27XX_ADC_CHANNEL(12, BIT(IIO_CHAN_INFO_PROCESSED)),
744 	SC27XX_ADC_CHANNEL(13, BIT(IIO_CHAN_INFO_PROCESSED)),
745 	SC27XX_ADC_CHANNEL(14, BIT(IIO_CHAN_INFO_PROCESSED)),
746 	SC27XX_ADC_CHANNEL(15, BIT(IIO_CHAN_INFO_PROCESSED)),
747 	SC27XX_ADC_CHANNEL(16, BIT(IIO_CHAN_INFO_PROCESSED)),
748 	SC27XX_ADC_CHANNEL(17, BIT(IIO_CHAN_INFO_PROCESSED)),
749 	SC27XX_ADC_CHANNEL(18, BIT(IIO_CHAN_INFO_PROCESSED)),
750 	SC27XX_ADC_CHANNEL(19, BIT(IIO_CHAN_INFO_PROCESSED)),
751 	SC27XX_ADC_CHANNEL(20, BIT(IIO_CHAN_INFO_RAW)),
752 	SC27XX_ADC_CHANNEL(21, BIT(IIO_CHAN_INFO_PROCESSED)),
753 	SC27XX_ADC_CHANNEL(22, BIT(IIO_CHAN_INFO_PROCESSED)),
754 	SC27XX_ADC_CHANNEL(23, BIT(IIO_CHAN_INFO_PROCESSED)),
755 	SC27XX_ADC_CHANNEL(24, BIT(IIO_CHAN_INFO_PROCESSED)),
756 	SC27XX_ADC_CHANNEL(25, BIT(IIO_CHAN_INFO_PROCESSED)),
757 	SC27XX_ADC_CHANNEL(26, BIT(IIO_CHAN_INFO_PROCESSED)),
758 	SC27XX_ADC_CHANNEL(27, BIT(IIO_CHAN_INFO_PROCESSED)),
759 	SC27XX_ADC_CHANNEL(28, BIT(IIO_CHAN_INFO_PROCESSED)),
760 	SC27XX_ADC_CHANNEL(29, BIT(IIO_CHAN_INFO_PROCESSED)),
761 	SC27XX_ADC_CHANNEL(30, BIT(IIO_CHAN_INFO_PROCESSED)),
762 	SC27XX_ADC_CHANNEL(31, BIT(IIO_CHAN_INFO_PROCESSED)),
763 };
764 
765 static int sc27xx_adc_enable(struct sc27xx_adc_data *data)
766 {
767 	int ret;
768 
769 	ret = regmap_update_bits(data->regmap, data->var_data->module_en,
770 				 SC27XX_MODULE_ADC_EN, SC27XX_MODULE_ADC_EN);
771 	if (ret)
772 		return ret;
773 
774 	/* Enable ADC work clock and controller clock */
775 	ret = regmap_update_bits(data->regmap, data->var_data->clk_en,
776 				 SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN,
777 				 SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN);
778 	if (ret)
779 		goto disable_adc;
780 
781 	/* ADC channel scales' calibration from nvmem device */
782 	ret = sc27xx_adc_scale_calibration(data, true);
783 	if (ret)
784 		goto disable_clk;
785 
786 	ret = sc27xx_adc_scale_calibration(data, false);
787 	if (ret)
788 		goto disable_clk;
789 
790 	return 0;
791 
792 disable_clk:
793 	regmap_update_bits(data->regmap, data->var_data->clk_en,
794 			   SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
795 disable_adc:
796 	regmap_update_bits(data->regmap, data->var_data->module_en,
797 			   SC27XX_MODULE_ADC_EN, 0);
798 
799 	return ret;
800 }
801 
802 static void sc27xx_adc_disable(void *_data)
803 {
804 	struct sc27xx_adc_data *data = _data;
805 
806 	/* Disable ADC work clock and controller clock */
807 	regmap_update_bits(data->regmap, data->var_data->clk_en,
808 			   SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
809 
810 	regmap_update_bits(data->regmap, data->var_data->module_en,
811 			   SC27XX_MODULE_ADC_EN, 0);
812 }
813 
814 static const struct sc27xx_adc_variant_data sc2731_data = {
815 	.module_en = SC2731_MODULE_EN,
816 	.clk_en = SC2731_ARM_CLK_EN,
817 	.scale_shift = SC27XX_ADC_SCALE_SHIFT,
818 	.scale_mask = SC27XX_ADC_SCALE_MASK,
819 	.bscale_cal = &sc2731_big_scale_graph_calib,
820 	.sscale_cal = &sc2731_small_scale_graph_calib,
821 	.init_scale = sc2731_adc_scale_init,
822 	.get_ratio = sc2731_adc_get_ratio,
823 	.set_volref = false,
824 };
825 
826 static const struct sc27xx_adc_variant_data sc2730_data = {
827 	.module_en = SC2730_MODULE_EN,
828 	.clk_en = SC2730_ARM_CLK_EN,
829 	.scale_shift = SC27XX_ADC_SCALE_SHIFT,
830 	.scale_mask = SC27XX_ADC_SCALE_MASK,
831 	.bscale_cal = &big_scale_graph_calib,
832 	.sscale_cal = &small_scale_graph_calib,
833 	.init_scale = sc2730_adc_scale_init,
834 	.get_ratio = sc2730_adc_get_ratio,
835 	.set_volref = false,
836 };
837 
838 static const struct sc27xx_adc_variant_data sc2721_data = {
839 	.module_en = SC2731_MODULE_EN,
840 	.clk_en = SC2721_ARM_CLK_EN,
841 	.scale_shift = SC2721_ADC_SCALE_SHIFT,
842 	.scale_mask = SC2721_ADC_SCALE_MASK,
843 	.bscale_cal = &sc2731_big_scale_graph_calib,
844 	.sscale_cal = &sc2731_small_scale_graph_calib,
845 	.init_scale = sc2731_adc_scale_init,
846 	.get_ratio = sc2721_adc_get_ratio,
847 	.set_volref = true,
848 };
849 
850 static const struct sc27xx_adc_variant_data sc2720_data = {
851 	.module_en = SC2731_MODULE_EN,
852 	.clk_en = SC2721_ARM_CLK_EN,
853 	.scale_shift = SC27XX_ADC_SCALE_SHIFT,
854 	.scale_mask = SC27XX_ADC_SCALE_MASK,
855 	.bscale_cal = &big_scale_graph_calib,
856 	.sscale_cal = &small_scale_graph_calib,
857 	.init_scale = sc2720_adc_scale_init,
858 	.get_ratio = sc2720_adc_get_ratio,
859 	.set_volref = false,
860 };
861 
862 static int sc27xx_adc_probe(struct platform_device *pdev)
863 {
864 	struct device *dev = &pdev->dev;
865 	struct device_node *np = dev->of_node;
866 	struct sc27xx_adc_data *sc27xx_data;
867 	const struct sc27xx_adc_variant_data *pdata;
868 	struct iio_dev *indio_dev;
869 	int ret;
870 
871 	pdata = of_device_get_match_data(dev);
872 	if (!pdata) {
873 		dev_err(dev, "No matching driver data found\n");
874 		return -EINVAL;
875 	}
876 
877 	indio_dev = devm_iio_device_alloc(dev, sizeof(*sc27xx_data));
878 	if (!indio_dev)
879 		return -ENOMEM;
880 
881 	sc27xx_data = iio_priv(indio_dev);
882 
883 	sc27xx_data->regmap = dev_get_regmap(dev->parent, NULL);
884 	if (!sc27xx_data->regmap) {
885 		dev_err(dev, "failed to get ADC regmap\n");
886 		return -ENODEV;
887 	}
888 
889 	ret = of_property_read_u32(np, "reg", &sc27xx_data->base);
890 	if (ret) {
891 		dev_err(dev, "failed to get ADC base address\n");
892 		return ret;
893 	}
894 
895 	sc27xx_data->irq = platform_get_irq(pdev, 0);
896 	if (sc27xx_data->irq < 0)
897 		return sc27xx_data->irq;
898 
899 	ret = of_hwspin_lock_get_id(np, 0);
900 	if (ret < 0) {
901 		dev_err(dev, "failed to get hwspinlock id\n");
902 		return ret;
903 	}
904 
905 	sc27xx_data->hwlock = devm_hwspin_lock_request_specific(dev, ret);
906 	if (!sc27xx_data->hwlock) {
907 		dev_err(dev, "failed to request hwspinlock\n");
908 		return -ENXIO;
909 	}
910 
911 	sc27xx_data->dev = dev;
912 	if (pdata->set_volref) {
913 		sc27xx_data->volref = devm_regulator_get(dev, "vref");
914 		if (IS_ERR(sc27xx_data->volref)) {
915 			ret = PTR_ERR(sc27xx_data->volref);
916 			return dev_err_probe(dev, ret, "failed to get ADC volref\n");
917 		}
918 	}
919 
920 	sc27xx_data->var_data = pdata;
921 	sc27xx_data->var_data->init_scale(sc27xx_data);
922 
923 	ret = sc27xx_adc_enable(sc27xx_data);
924 	if (ret) {
925 		dev_err(dev, "failed to enable ADC module\n");
926 		return ret;
927 	}
928 
929 	ret = devm_add_action_or_reset(dev, sc27xx_adc_disable, sc27xx_data);
930 	if (ret) {
931 		dev_err(dev, "failed to add ADC disable action\n");
932 		return ret;
933 	}
934 
935 	indio_dev->name = dev_name(dev);
936 	indio_dev->modes = INDIO_DIRECT_MODE;
937 	indio_dev->info = &sc27xx_info;
938 	indio_dev->channels = sc27xx_channels;
939 	indio_dev->num_channels = ARRAY_SIZE(sc27xx_channels);
940 
941 	mutex_init(&sc27xx_data->lock);
942 
943 	ret = devm_iio_device_register(dev, indio_dev);
944 	if (ret)
945 		dev_err(dev, "could not register iio (ADC)");
946 
947 	return ret;
948 }
949 
950 static const struct of_device_id sc27xx_adc_of_match[] = {
951 	{ .compatible = "sprd,sc2731-adc", .data = &sc2731_data},
952 	{ .compatible = "sprd,sc2730-adc", .data = &sc2730_data},
953 	{ .compatible = "sprd,sc2721-adc", .data = &sc2721_data},
954 	{ .compatible = "sprd,sc2720-adc", .data = &sc2720_data},
955 	{ }
956 };
957 MODULE_DEVICE_TABLE(of, sc27xx_adc_of_match);
958 
959 static struct platform_driver sc27xx_adc_driver = {
960 	.probe = sc27xx_adc_probe,
961 	.driver = {
962 		.name = "sc27xx-adc",
963 		.of_match_table = sc27xx_adc_of_match,
964 	},
965 };
966 
967 module_platform_driver(sc27xx_adc_driver);
968 
969 MODULE_AUTHOR("Freeman Liu <freeman.liu@spreadtrum.com>");
970 MODULE_DESCRIPTION("Spreadtrum SC27XX ADC Driver");
971 MODULE_LICENSE("GPL v2");
972