xref: /openbmc/linux/drivers/iio/adc/sc27xx_adc.c (revision 1240c94c)
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/platform_device.h>
11 #include <linux/regmap.h>
12 #include <linux/regulator/consumer.h>
13 #include <linux/slab.h>
14 
15 /* PMIC global registers definition */
16 #define SC2730_MODULE_EN		0x1808
17 #define SC2731_MODULE_EN		0xc08
18 #define SC27XX_MODULE_ADC_EN		BIT(5)
19 #define SC2721_ARM_CLK_EN		0xc0c
20 #define SC2730_ARM_CLK_EN		0x180c
21 #define SC2731_ARM_CLK_EN		0xc10
22 #define SC27XX_CLK_ADC_EN		BIT(5)
23 #define SC27XX_CLK_ADC_CLK_EN		BIT(6)
24 
25 /* ADC controller registers definition */
26 #define SC27XX_ADC_CTL			0x0
27 #define SC27XX_ADC_CH_CFG		0x4
28 #define SC27XX_ADC_DATA			0x4c
29 #define SC27XX_ADC_INT_EN		0x50
30 #define SC27XX_ADC_INT_CLR		0x54
31 #define SC27XX_ADC_INT_STS		0x58
32 #define SC27XX_ADC_INT_RAW		0x5c
33 
34 /* Bits and mask definition for SC27XX_ADC_CTL register */
35 #define SC27XX_ADC_EN			BIT(0)
36 #define SC27XX_ADC_CHN_RUN		BIT(1)
37 #define SC27XX_ADC_12BIT_MODE		BIT(2)
38 #define SC27XX_ADC_RUN_NUM_MASK		GENMASK(7, 4)
39 #define SC27XX_ADC_RUN_NUM_SHIFT	4
40 
41 /* Bits and mask definition for SC27XX_ADC_CH_CFG register */
42 #define SC27XX_ADC_CHN_ID_MASK		GENMASK(4, 0)
43 #define SC27XX_ADC_SCALE_MASK		GENMASK(10, 9)
44 #define SC2721_ADC_SCALE_MASK		BIT(5)
45 #define SC27XX_ADC_SCALE_SHIFT		9
46 #define SC2721_ADC_SCALE_SHIFT		5
47 
48 /* Bits definitions for SC27XX_ADC_INT_EN registers */
49 #define SC27XX_ADC_IRQ_EN		BIT(0)
50 
51 /* Bits definitions for SC27XX_ADC_INT_CLR registers */
52 #define SC27XX_ADC_IRQ_CLR		BIT(0)
53 
54 /* Bits definitions for SC27XX_ADC_INT_RAW registers */
55 #define SC27XX_ADC_IRQ_RAW		BIT(0)
56 
57 /* Mask definition for SC27XX_ADC_DATA register */
58 #define SC27XX_ADC_DATA_MASK		GENMASK(11, 0)
59 
60 /* Timeout (ms) for the trylock of hardware spinlocks */
61 #define SC27XX_ADC_HWLOCK_TIMEOUT	5000
62 
63 /* Timeout (us) for ADC data conversion according to ADC datasheet */
64 #define SC27XX_ADC_RDY_TIMEOUT		1000000
65 #define SC27XX_ADC_POLL_RAW_STATUS	500
66 
67 /* Maximum ADC channel number */
68 #define SC27XX_ADC_CHANNEL_MAX		32
69 
70 /* ADC voltage ratio definition */
71 #define SC27XX_VOLT_RATIO(n, d)		\
72 	(((n) << SC27XX_RATIO_NUMERATOR_OFFSET) | (d))
73 #define SC27XX_RATIO_NUMERATOR_OFFSET	16
74 #define SC27XX_RATIO_DENOMINATOR_MASK	GENMASK(15, 0)
75 
76 /* ADC specific channel reference voltage 3.5V */
77 #define SC27XX_ADC_REFVOL_VDD35		3500000
78 
79 /* ADC default channel reference voltage is 2.8V */
80 #define SC27XX_ADC_REFVOL_VDD28		2800000
81 
82 struct sc27xx_adc_data {
83 	struct device *dev;
84 	struct regulator *volref;
85 	struct regmap *regmap;
86 	/* lock to protect against multiple access to the device */
87 	struct mutex lock;
88 	/*
89 	 * One hardware spinlock to synchronize between the multiple
90 	 * subsystems which will access the unique ADC controller.
91 	 */
92 	struct hwspinlock *hwlock;
93 	int channel_scale[SC27XX_ADC_CHANNEL_MAX];
94 	u32 base;
95 	int irq;
96 	const struct sc27xx_adc_variant_data *var_data;
97 };
98 
99 /*
100  * Since different PMICs of SC27xx series can have different
101  * address and ratio, we should save ratio config and base
102  * in the device data structure.
103  */
104 struct sc27xx_adc_variant_data {
105 	u32 module_en;
106 	u32 clk_en;
107 	u32 scale_shift;
108 	u32 scale_mask;
109 	const struct sc27xx_adc_linear_graph *bscale_cal;
110 	const struct sc27xx_adc_linear_graph *sscale_cal;
111 	void (*init_scale)(struct sc27xx_adc_data *data);
112 	int (*get_ratio)(int channel, int scale);
113 	bool set_volref;
114 };
115 
116 struct sc27xx_adc_linear_graph {
117 	int volt0;
118 	int adc0;
119 	int volt1;
120 	int adc1;
121 };
122 
123 /*
124  * According to the datasheet, we can convert one ADC value to one voltage value
125  * through 2 points in the linear graph. If the voltage is less than 1.2v, we
126  * should use the small-scale graph, and if more than 1.2v, we should use the
127  * big-scale graph.
128  */
129 static struct sc27xx_adc_linear_graph big_scale_graph = {
130 	4200, 3310,
131 	3600, 2832,
132 };
133 
134 static struct sc27xx_adc_linear_graph small_scale_graph = {
135 	1000, 3413,
136 	100, 341,
137 };
138 
139 static const struct sc27xx_adc_linear_graph sc2731_big_scale_graph_calib = {
140 	4200, 850,
141 	3600, 728,
142 };
143 
144 static const struct sc27xx_adc_linear_graph sc2731_small_scale_graph_calib = {
145 	1000, 838,
146 	100, 84,
147 };
148 
149 static const struct sc27xx_adc_linear_graph big_scale_graph_calib = {
150 	4200, 856,
151 	3600, 733,
152 };
153 
154 static const struct sc27xx_adc_linear_graph small_scale_graph_calib = {
155 	1000, 833,
156 	100, 80,
157 };
158 
sc27xx_adc_get_calib_data(u32 calib_data,int calib_adc)159 static int sc27xx_adc_get_calib_data(u32 calib_data, int calib_adc)
160 {
161 	return ((calib_data & 0xff) + calib_adc - 128) * 4;
162 }
163 
164 /* get the adc nvmem cell calibration data */
adc_nvmem_cell_calib_data(struct sc27xx_adc_data * data,const char * cell_name)165 static int adc_nvmem_cell_calib_data(struct sc27xx_adc_data *data, const char *cell_name)
166 {
167 	struct nvmem_cell *cell;
168 	void *buf;
169 	u32 origin_calib_data = 0;
170 	size_t len;
171 
172 	if (!data)
173 		return -EINVAL;
174 
175 	cell = nvmem_cell_get(data->dev, cell_name);
176 	if (IS_ERR(cell))
177 		return PTR_ERR(cell);
178 
179 	buf = nvmem_cell_read(cell, &len);
180 	if (IS_ERR(buf)) {
181 		nvmem_cell_put(cell);
182 		return PTR_ERR(buf);
183 	}
184 
185 	memcpy(&origin_calib_data, buf, min(len, sizeof(u32)));
186 
187 	kfree(buf);
188 	nvmem_cell_put(cell);
189 	return origin_calib_data;
190 }
191 
sc27xx_adc_scale_calibration(struct sc27xx_adc_data * data,bool big_scale)192 static int sc27xx_adc_scale_calibration(struct sc27xx_adc_data *data,
193 					bool big_scale)
194 {
195 	const struct sc27xx_adc_linear_graph *calib_graph;
196 	struct sc27xx_adc_linear_graph *graph;
197 	const char *cell_name;
198 	u32 calib_data = 0;
199 
200 	if (big_scale) {
201 		calib_graph = data->var_data->bscale_cal;
202 		graph = &big_scale_graph;
203 		cell_name = "big_scale_calib";
204 	} else {
205 		calib_graph = data->var_data->sscale_cal;
206 		graph = &small_scale_graph;
207 		cell_name = "small_scale_calib";
208 	}
209 
210 	calib_data = adc_nvmem_cell_calib_data(data, cell_name);
211 
212 	/* Only need to calibrate the adc values in the linear graph. */
213 	graph->adc0 = sc27xx_adc_get_calib_data(calib_data, calib_graph->adc0);
214 	graph->adc1 = sc27xx_adc_get_calib_data(calib_data >> 8,
215 						calib_graph->adc1);
216 
217 	return 0;
218 }
219 
sc2720_adc_get_ratio(int channel,int scale)220 static int sc2720_adc_get_ratio(int channel, int scale)
221 {
222 	switch (channel) {
223 	case 14:
224 		switch (scale) {
225 		case 0:
226 			return SC27XX_VOLT_RATIO(68, 900);
227 		case 1:
228 			return SC27XX_VOLT_RATIO(68, 1760);
229 		case 2:
230 			return SC27XX_VOLT_RATIO(68, 2327);
231 		case 3:
232 			return SC27XX_VOLT_RATIO(68, 3654);
233 		default:
234 			return SC27XX_VOLT_RATIO(1, 1);
235 		}
236 	case 16:
237 		switch (scale) {
238 		case 0:
239 			return SC27XX_VOLT_RATIO(48, 100);
240 		case 1:
241 			return SC27XX_VOLT_RATIO(480, 1955);
242 		case 2:
243 			return SC27XX_VOLT_RATIO(480, 2586);
244 		case 3:
245 			return SC27XX_VOLT_RATIO(48, 406);
246 		default:
247 			return SC27XX_VOLT_RATIO(1, 1);
248 		}
249 	case 21:
250 	case 22:
251 	case 23:
252 		switch (scale) {
253 		case 0:
254 			return SC27XX_VOLT_RATIO(3, 8);
255 		case 1:
256 			return SC27XX_VOLT_RATIO(375, 1955);
257 		case 2:
258 			return SC27XX_VOLT_RATIO(375, 2586);
259 		case 3:
260 			return SC27XX_VOLT_RATIO(300, 3248);
261 		default:
262 			return SC27XX_VOLT_RATIO(1, 1);
263 		}
264 	default:
265 		switch (scale) {
266 		case 0:
267 			return SC27XX_VOLT_RATIO(1, 1);
268 		case 1:
269 			return SC27XX_VOLT_RATIO(1000, 1955);
270 		case 2:
271 			return SC27XX_VOLT_RATIO(1000, 2586);
272 		case 3:
273 			return SC27XX_VOLT_RATIO(100, 406);
274 		default:
275 			return SC27XX_VOLT_RATIO(1, 1);
276 		}
277 	}
278 	return SC27XX_VOLT_RATIO(1, 1);
279 }
280 
sc2721_adc_get_ratio(int channel,int scale)281 static int sc2721_adc_get_ratio(int channel, int scale)
282 {
283 	switch (channel) {
284 	case 1:
285 	case 2:
286 	case 3:
287 	case 4:
288 		return scale ? SC27XX_VOLT_RATIO(400, 1025) :
289 			SC27XX_VOLT_RATIO(1, 1);
290 	case 5:
291 		return SC27XX_VOLT_RATIO(7, 29);
292 	case 7:
293 	case 9:
294 		return scale ? SC27XX_VOLT_RATIO(100, 125) :
295 			SC27XX_VOLT_RATIO(1, 1);
296 	case 14:
297 		return SC27XX_VOLT_RATIO(68, 900);
298 	case 16:
299 		return SC27XX_VOLT_RATIO(48, 100);
300 	case 19:
301 		return SC27XX_VOLT_RATIO(1, 3);
302 	default:
303 		return SC27XX_VOLT_RATIO(1, 1);
304 	}
305 	return SC27XX_VOLT_RATIO(1, 1);
306 }
307 
sc2730_adc_get_ratio(int channel,int scale)308 static int sc2730_adc_get_ratio(int channel, int scale)
309 {
310 	switch (channel) {
311 	case 14:
312 		switch (scale) {
313 		case 0:
314 			return SC27XX_VOLT_RATIO(68, 900);
315 		case 1:
316 			return SC27XX_VOLT_RATIO(68, 1760);
317 		case 2:
318 			return SC27XX_VOLT_RATIO(68, 2327);
319 		case 3:
320 			return SC27XX_VOLT_RATIO(68, 3654);
321 		default:
322 			return SC27XX_VOLT_RATIO(1, 1);
323 		}
324 	case 15:
325 		switch (scale) {
326 		case 0:
327 			return SC27XX_VOLT_RATIO(1, 3);
328 		case 1:
329 			return SC27XX_VOLT_RATIO(1000, 5865);
330 		case 2:
331 			return SC27XX_VOLT_RATIO(500, 3879);
332 		case 3:
333 			return SC27XX_VOLT_RATIO(500, 6090);
334 		default:
335 			return SC27XX_VOLT_RATIO(1, 1);
336 		}
337 	case 16:
338 		switch (scale) {
339 		case 0:
340 			return SC27XX_VOLT_RATIO(48, 100);
341 		case 1:
342 			return SC27XX_VOLT_RATIO(480, 1955);
343 		case 2:
344 			return SC27XX_VOLT_RATIO(480, 2586);
345 		case 3:
346 			return SC27XX_VOLT_RATIO(48, 406);
347 		default:
348 			return SC27XX_VOLT_RATIO(1, 1);
349 		}
350 	case 21:
351 	case 22:
352 	case 23:
353 		switch (scale) {
354 		case 0:
355 			return SC27XX_VOLT_RATIO(3, 8);
356 		case 1:
357 			return SC27XX_VOLT_RATIO(375, 1955);
358 		case 2:
359 			return SC27XX_VOLT_RATIO(375, 2586);
360 		case 3:
361 			return SC27XX_VOLT_RATIO(300, 3248);
362 		default:
363 			return SC27XX_VOLT_RATIO(1, 1);
364 		}
365 	default:
366 		switch (scale) {
367 		case 0:
368 			return SC27XX_VOLT_RATIO(1, 1);
369 		case 1:
370 			return SC27XX_VOLT_RATIO(1000, 1955);
371 		case 2:
372 			return SC27XX_VOLT_RATIO(1000, 2586);
373 		case 3:
374 			return SC27XX_VOLT_RATIO(1000, 4060);
375 		default:
376 			return SC27XX_VOLT_RATIO(1, 1);
377 		}
378 	}
379 	return SC27XX_VOLT_RATIO(1, 1);
380 }
381 
sc2731_adc_get_ratio(int channel,int scale)382 static int sc2731_adc_get_ratio(int channel, int scale)
383 {
384 	switch (channel) {
385 	case 1:
386 	case 2:
387 	case 3:
388 	case 4:
389 		return scale ? SC27XX_VOLT_RATIO(400, 1025) :
390 			SC27XX_VOLT_RATIO(1, 1);
391 	case 5:
392 		return SC27XX_VOLT_RATIO(7, 29);
393 	case 6:
394 		return SC27XX_VOLT_RATIO(375, 9000);
395 	case 7:
396 	case 8:
397 		return scale ? SC27XX_VOLT_RATIO(100, 125) :
398 			SC27XX_VOLT_RATIO(1, 1);
399 	case 19:
400 		return SC27XX_VOLT_RATIO(1, 3);
401 	default:
402 		return SC27XX_VOLT_RATIO(1, 1);
403 	}
404 	return SC27XX_VOLT_RATIO(1, 1);
405 }
406 
407 /*
408  * According to the datasheet set specific value on some channel.
409  */
sc2720_adc_scale_init(struct sc27xx_adc_data * data)410 static void sc2720_adc_scale_init(struct sc27xx_adc_data *data)
411 {
412 	int i;
413 
414 	for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
415 		switch (i) {
416 		case 5:
417 			data->channel_scale[i] = 3;
418 			break;
419 		case 7:
420 		case 9:
421 			data->channel_scale[i] = 2;
422 			break;
423 		case 13:
424 			data->channel_scale[i] = 1;
425 			break;
426 		case 19:
427 		case 30:
428 		case 31:
429 			data->channel_scale[i] = 3;
430 			break;
431 		default:
432 			data->channel_scale[i] = 0;
433 			break;
434 		}
435 	}
436 }
437 
sc2730_adc_scale_init(struct sc27xx_adc_data * data)438 static void sc2730_adc_scale_init(struct sc27xx_adc_data *data)
439 {
440 	int i;
441 
442 	for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
443 		switch (i) {
444 		case 5:
445 		case 10:
446 		case 19:
447 		case 30:
448 		case 31:
449 			data->channel_scale[i] = 3;
450 			break;
451 		case 7:
452 		case 9:
453 			data->channel_scale[i] = 2;
454 			break;
455 		case 13:
456 			data->channel_scale[i] = 1;
457 			break;
458 		default:
459 			data->channel_scale[i] = 0;
460 			break;
461 		}
462 	}
463 }
464 
sc2731_adc_scale_init(struct sc27xx_adc_data * data)465 static void sc2731_adc_scale_init(struct sc27xx_adc_data *data)
466 {
467 	int i;
468 	/*
469 	 * In the current software design, SC2731 support 2 scales,
470 	 * channels 5 uses big scale, others use smale.
471 	 */
472 	for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
473 		switch (i) {
474 		case 5:
475 			data->channel_scale[i] = 1;
476 			break;
477 		default:
478 			data->channel_scale[i] = 0;
479 			break;
480 		}
481 	}
482 }
483 
sc27xx_adc_read(struct sc27xx_adc_data * data,int channel,int scale,int * val)484 static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel,
485 			   int scale, int *val)
486 {
487 	int ret, ret_volref;
488 	u32 tmp, value, status;
489 
490 	ret = hwspin_lock_timeout_raw(data->hwlock, SC27XX_ADC_HWLOCK_TIMEOUT);
491 	if (ret) {
492 		dev_err(data->dev, "timeout to get the hwspinlock\n");
493 		return ret;
494 	}
495 
496 	/*
497 	 * According to the sc2721 chip data sheet, the reference voltage of
498 	 * specific channel 30 and channel 31 in ADC module needs to be set from
499 	 * the default 2.8v to 3.5v.
500 	 */
501 	if ((data->var_data->set_volref) && (channel == 30 || channel == 31)) {
502 		ret = regulator_set_voltage(data->volref,
503 					SC27XX_ADC_REFVOL_VDD35,
504 					SC27XX_ADC_REFVOL_VDD35);
505 		if (ret) {
506 			dev_err(data->dev, "failed to set the volref 3.5v\n");
507 			goto unlock_adc;
508 		}
509 	}
510 
511 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
512 				 SC27XX_ADC_EN, SC27XX_ADC_EN);
513 	if (ret)
514 		goto regulator_restore;
515 
516 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_CLR,
517 				 SC27XX_ADC_IRQ_CLR, SC27XX_ADC_IRQ_CLR);
518 	if (ret)
519 		goto disable_adc;
520 
521 	/* Configure the channel id and scale */
522 	tmp = (scale << data->var_data->scale_shift) & data->var_data->scale_mask;
523 	tmp |= channel & SC27XX_ADC_CHN_ID_MASK;
524 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CH_CFG,
525 				 SC27XX_ADC_CHN_ID_MASK |
526 				 data->var_data->scale_mask,
527 				 tmp);
528 	if (ret)
529 		goto disable_adc;
530 
531 	/* Select 12bit conversion mode, and only sample 1 time */
532 	tmp = SC27XX_ADC_12BIT_MODE;
533 	tmp |= (0 << SC27XX_ADC_RUN_NUM_SHIFT) & SC27XX_ADC_RUN_NUM_MASK;
534 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
535 				 SC27XX_ADC_RUN_NUM_MASK | SC27XX_ADC_12BIT_MODE,
536 				 tmp);
537 	if (ret)
538 		goto disable_adc;
539 
540 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
541 				 SC27XX_ADC_CHN_RUN, SC27XX_ADC_CHN_RUN);
542 	if (ret)
543 		goto disable_adc;
544 
545 	ret = regmap_read_poll_timeout(data->regmap,
546 				       data->base + SC27XX_ADC_INT_RAW,
547 				       status, (status & SC27XX_ADC_IRQ_RAW),
548 				       SC27XX_ADC_POLL_RAW_STATUS,
549 				       SC27XX_ADC_RDY_TIMEOUT);
550 	if (ret) {
551 		dev_err(data->dev, "read adc timeout, status = 0x%x\n", status);
552 		goto disable_adc;
553 	}
554 
555 	ret = regmap_read(data->regmap, data->base + SC27XX_ADC_DATA, &value);
556 	if (ret)
557 		goto disable_adc;
558 
559 	value &= SC27XX_ADC_DATA_MASK;
560 
561 disable_adc:
562 	regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
563 			   SC27XX_ADC_EN, 0);
564 regulator_restore:
565 	if ((data->var_data->set_volref) && (channel == 30 || channel == 31)) {
566 		ret_volref = regulator_set_voltage(data->volref,
567 					    SC27XX_ADC_REFVOL_VDD28,
568 					    SC27XX_ADC_REFVOL_VDD28);
569 		if (ret_volref) {
570 			dev_err(data->dev, "failed to set the volref 2.8v,ret_volref = 0x%x\n",
571 					 ret_volref);
572 			ret = ret || ret_volref;
573 		}
574 	}
575 unlock_adc:
576 	hwspin_unlock_raw(data->hwlock);
577 
578 	if (!ret)
579 		*val = value;
580 
581 	return ret;
582 }
583 
sc27xx_adc_volt_ratio(struct sc27xx_adc_data * data,int channel,int scale,struct u32_fract * fract)584 static void sc27xx_adc_volt_ratio(struct sc27xx_adc_data *data, int channel, int scale,
585 				  struct u32_fract *fract)
586 {
587 	u32 ratio;
588 
589 	ratio = data->var_data->get_ratio(channel, scale);
590 	fract->numerator = ratio >> SC27XX_RATIO_NUMERATOR_OFFSET;
591 	fract->denominator = ratio & SC27XX_RATIO_DENOMINATOR_MASK;
592 }
593 
adc_to_volt(struct sc27xx_adc_linear_graph * graph,int raw_adc)594 static int adc_to_volt(struct sc27xx_adc_linear_graph *graph,
595 			      int raw_adc)
596 {
597 	int tmp;
598 
599 	tmp = (graph->volt0 - graph->volt1) * (raw_adc - graph->adc1);
600 	tmp /= (graph->adc0 - graph->adc1);
601 	tmp += graph->volt1;
602 
603 	return tmp;
604 }
605 
sc27xx_adc_to_volt(struct sc27xx_adc_linear_graph * graph,int raw_adc)606 static int sc27xx_adc_to_volt(struct sc27xx_adc_linear_graph *graph,
607 			      int raw_adc)
608 {
609 	int tmp;
610 
611 	tmp = adc_to_volt(graph, raw_adc);
612 
613 	return tmp < 0 ? 0 : tmp;
614 }
615 
sc27xx_adc_convert_volt(struct sc27xx_adc_data * data,int channel,int scale,int raw_adc)616 static int sc27xx_adc_convert_volt(struct sc27xx_adc_data *data, int channel,
617 				   int scale, int raw_adc)
618 {
619 	struct u32_fract fract;
620 	u32 volt;
621 
622 	/*
623 	 * Convert ADC values to voltage values according to the linear graph,
624 	 * and channel 5 and channel 1 has been calibrated, so we can just
625 	 * return the voltage values calculated by the linear graph. But other
626 	 * channels need be calculated to the real voltage values with the
627 	 * voltage ratio.
628 	 */
629 	switch (channel) {
630 	case 5:
631 		return sc27xx_adc_to_volt(&big_scale_graph, raw_adc);
632 
633 	case 1:
634 		return sc27xx_adc_to_volt(&small_scale_graph, raw_adc);
635 
636 	default:
637 		volt = sc27xx_adc_to_volt(&small_scale_graph, raw_adc);
638 		break;
639 	}
640 
641 	sc27xx_adc_volt_ratio(data, channel, scale, &fract);
642 
643 	return DIV_ROUND_CLOSEST(volt * fract.denominator, fract.numerator);
644 }
645 
sc27xx_adc_read_processed(struct sc27xx_adc_data * data,int channel,int scale,int * val)646 static int sc27xx_adc_read_processed(struct sc27xx_adc_data *data,
647 				     int channel, int scale, int *val)
648 {
649 	int ret, raw_adc;
650 
651 	ret = sc27xx_adc_read(data, channel, scale, &raw_adc);
652 	if (ret)
653 		return ret;
654 
655 	*val = sc27xx_adc_convert_volt(data, channel, scale, raw_adc);
656 	return 0;
657 }
658 
sc27xx_adc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)659 static int sc27xx_adc_read_raw(struct iio_dev *indio_dev,
660 			       struct iio_chan_spec const *chan,
661 			       int *val, int *val2, long mask)
662 {
663 	struct sc27xx_adc_data *data = iio_priv(indio_dev);
664 	int scale = data->channel_scale[chan->channel];
665 	int ret, tmp;
666 
667 	switch (mask) {
668 	case IIO_CHAN_INFO_RAW:
669 		mutex_lock(&data->lock);
670 		ret = sc27xx_adc_read(data, chan->channel, scale, &tmp);
671 		mutex_unlock(&data->lock);
672 
673 		if (ret)
674 			return ret;
675 
676 		*val = tmp;
677 		return IIO_VAL_INT;
678 
679 	case IIO_CHAN_INFO_PROCESSED:
680 		mutex_lock(&data->lock);
681 		ret = sc27xx_adc_read_processed(data, chan->channel, scale,
682 						&tmp);
683 		mutex_unlock(&data->lock);
684 
685 		if (ret)
686 			return ret;
687 
688 		*val = tmp;
689 		return IIO_VAL_INT;
690 
691 	case IIO_CHAN_INFO_SCALE:
692 		*val = scale;
693 		return IIO_VAL_INT;
694 
695 	default:
696 		return -EINVAL;
697 	}
698 }
699 
sc27xx_adc_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)700 static int sc27xx_adc_write_raw(struct iio_dev *indio_dev,
701 				struct iio_chan_spec const *chan,
702 				int val, int val2, long mask)
703 {
704 	struct sc27xx_adc_data *data = iio_priv(indio_dev);
705 
706 	switch (mask) {
707 	case IIO_CHAN_INFO_SCALE:
708 		data->channel_scale[chan->channel] = val;
709 		return IIO_VAL_INT;
710 
711 	default:
712 		return -EINVAL;
713 	}
714 }
715 
716 static const struct iio_info sc27xx_info = {
717 	.read_raw = &sc27xx_adc_read_raw,
718 	.write_raw = &sc27xx_adc_write_raw,
719 };
720 
721 #define SC27XX_ADC_CHANNEL(index, mask) {			\
722 	.type = IIO_VOLTAGE,					\
723 	.channel = index,					\
724 	.info_mask_separate = mask | BIT(IIO_CHAN_INFO_SCALE),	\
725 	.datasheet_name = "CH##index",				\
726 	.indexed = 1,						\
727 }
728 
729 static const struct iio_chan_spec sc27xx_channels[] = {
730 	SC27XX_ADC_CHANNEL(0, BIT(IIO_CHAN_INFO_PROCESSED)),
731 	SC27XX_ADC_CHANNEL(1, BIT(IIO_CHAN_INFO_PROCESSED)),
732 	SC27XX_ADC_CHANNEL(2, BIT(IIO_CHAN_INFO_PROCESSED)),
733 	SC27XX_ADC_CHANNEL(3, BIT(IIO_CHAN_INFO_PROCESSED)),
734 	SC27XX_ADC_CHANNEL(4, BIT(IIO_CHAN_INFO_PROCESSED)),
735 	SC27XX_ADC_CHANNEL(5, BIT(IIO_CHAN_INFO_PROCESSED)),
736 	SC27XX_ADC_CHANNEL(6, BIT(IIO_CHAN_INFO_PROCESSED)),
737 	SC27XX_ADC_CHANNEL(7, BIT(IIO_CHAN_INFO_PROCESSED)),
738 	SC27XX_ADC_CHANNEL(8, BIT(IIO_CHAN_INFO_PROCESSED)),
739 	SC27XX_ADC_CHANNEL(9, BIT(IIO_CHAN_INFO_PROCESSED)),
740 	SC27XX_ADC_CHANNEL(10, BIT(IIO_CHAN_INFO_PROCESSED)),
741 	SC27XX_ADC_CHANNEL(11, BIT(IIO_CHAN_INFO_PROCESSED)),
742 	SC27XX_ADC_CHANNEL(12, BIT(IIO_CHAN_INFO_PROCESSED)),
743 	SC27XX_ADC_CHANNEL(13, BIT(IIO_CHAN_INFO_PROCESSED)),
744 	SC27XX_ADC_CHANNEL(14, BIT(IIO_CHAN_INFO_PROCESSED)),
745 	SC27XX_ADC_CHANNEL(15, BIT(IIO_CHAN_INFO_PROCESSED)),
746 	SC27XX_ADC_CHANNEL(16, BIT(IIO_CHAN_INFO_PROCESSED)),
747 	SC27XX_ADC_CHANNEL(17, BIT(IIO_CHAN_INFO_PROCESSED)),
748 	SC27XX_ADC_CHANNEL(18, BIT(IIO_CHAN_INFO_PROCESSED)),
749 	SC27XX_ADC_CHANNEL(19, BIT(IIO_CHAN_INFO_PROCESSED)),
750 	SC27XX_ADC_CHANNEL(20, BIT(IIO_CHAN_INFO_RAW)),
751 	SC27XX_ADC_CHANNEL(21, BIT(IIO_CHAN_INFO_PROCESSED)),
752 	SC27XX_ADC_CHANNEL(22, BIT(IIO_CHAN_INFO_PROCESSED)),
753 	SC27XX_ADC_CHANNEL(23, BIT(IIO_CHAN_INFO_PROCESSED)),
754 	SC27XX_ADC_CHANNEL(24, BIT(IIO_CHAN_INFO_PROCESSED)),
755 	SC27XX_ADC_CHANNEL(25, BIT(IIO_CHAN_INFO_PROCESSED)),
756 	SC27XX_ADC_CHANNEL(26, BIT(IIO_CHAN_INFO_PROCESSED)),
757 	SC27XX_ADC_CHANNEL(27, BIT(IIO_CHAN_INFO_PROCESSED)),
758 	SC27XX_ADC_CHANNEL(28, BIT(IIO_CHAN_INFO_PROCESSED)),
759 	SC27XX_ADC_CHANNEL(29, BIT(IIO_CHAN_INFO_PROCESSED)),
760 	SC27XX_ADC_CHANNEL(30, BIT(IIO_CHAN_INFO_PROCESSED)),
761 	SC27XX_ADC_CHANNEL(31, BIT(IIO_CHAN_INFO_PROCESSED)),
762 };
763 
sc27xx_adc_enable(struct sc27xx_adc_data * data)764 static int sc27xx_adc_enable(struct sc27xx_adc_data *data)
765 {
766 	int ret;
767 
768 	ret = regmap_update_bits(data->regmap, data->var_data->module_en,
769 				 SC27XX_MODULE_ADC_EN, SC27XX_MODULE_ADC_EN);
770 	if (ret)
771 		return ret;
772 
773 	/* Enable ADC work clock and controller clock */
774 	ret = regmap_update_bits(data->regmap, data->var_data->clk_en,
775 				 SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN,
776 				 SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN);
777 	if (ret)
778 		goto disable_adc;
779 
780 	/* ADC channel scales' calibration from nvmem device */
781 	ret = sc27xx_adc_scale_calibration(data, true);
782 	if (ret)
783 		goto disable_clk;
784 
785 	ret = sc27xx_adc_scale_calibration(data, false);
786 	if (ret)
787 		goto disable_clk;
788 
789 	return 0;
790 
791 disable_clk:
792 	regmap_update_bits(data->regmap, data->var_data->clk_en,
793 			   SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
794 disable_adc:
795 	regmap_update_bits(data->regmap, data->var_data->module_en,
796 			   SC27XX_MODULE_ADC_EN, 0);
797 
798 	return ret;
799 }
800 
sc27xx_adc_disable(void * _data)801 static void sc27xx_adc_disable(void *_data)
802 {
803 	struct sc27xx_adc_data *data = _data;
804 
805 	/* Disable ADC work clock and controller clock */
806 	regmap_update_bits(data->regmap, data->var_data->clk_en,
807 			   SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
808 
809 	regmap_update_bits(data->regmap, data->var_data->module_en,
810 			   SC27XX_MODULE_ADC_EN, 0);
811 }
812 
813 static const struct sc27xx_adc_variant_data sc2731_data = {
814 	.module_en = SC2731_MODULE_EN,
815 	.clk_en = SC2731_ARM_CLK_EN,
816 	.scale_shift = SC27XX_ADC_SCALE_SHIFT,
817 	.scale_mask = SC27XX_ADC_SCALE_MASK,
818 	.bscale_cal = &sc2731_big_scale_graph_calib,
819 	.sscale_cal = &sc2731_small_scale_graph_calib,
820 	.init_scale = sc2731_adc_scale_init,
821 	.get_ratio = sc2731_adc_get_ratio,
822 	.set_volref = false,
823 };
824 
825 static const struct sc27xx_adc_variant_data sc2730_data = {
826 	.module_en = SC2730_MODULE_EN,
827 	.clk_en = SC2730_ARM_CLK_EN,
828 	.scale_shift = SC27XX_ADC_SCALE_SHIFT,
829 	.scale_mask = SC27XX_ADC_SCALE_MASK,
830 	.bscale_cal = &big_scale_graph_calib,
831 	.sscale_cal = &small_scale_graph_calib,
832 	.init_scale = sc2730_adc_scale_init,
833 	.get_ratio = sc2730_adc_get_ratio,
834 	.set_volref = false,
835 };
836 
837 static const struct sc27xx_adc_variant_data sc2721_data = {
838 	.module_en = SC2731_MODULE_EN,
839 	.clk_en = SC2721_ARM_CLK_EN,
840 	.scale_shift = SC2721_ADC_SCALE_SHIFT,
841 	.scale_mask = SC2721_ADC_SCALE_MASK,
842 	.bscale_cal = &sc2731_big_scale_graph_calib,
843 	.sscale_cal = &sc2731_small_scale_graph_calib,
844 	.init_scale = sc2731_adc_scale_init,
845 	.get_ratio = sc2721_adc_get_ratio,
846 	.set_volref = true,
847 };
848 
849 static const struct sc27xx_adc_variant_data sc2720_data = {
850 	.module_en = SC2731_MODULE_EN,
851 	.clk_en = SC2721_ARM_CLK_EN,
852 	.scale_shift = SC27XX_ADC_SCALE_SHIFT,
853 	.scale_mask = SC27XX_ADC_SCALE_MASK,
854 	.bscale_cal = &big_scale_graph_calib,
855 	.sscale_cal = &small_scale_graph_calib,
856 	.init_scale = sc2720_adc_scale_init,
857 	.get_ratio = sc2720_adc_get_ratio,
858 	.set_volref = false,
859 };
860 
sc27xx_adc_probe(struct platform_device * pdev)861 static int sc27xx_adc_probe(struct platform_device *pdev)
862 {
863 	struct device *dev = &pdev->dev;
864 	struct device_node *np = dev->of_node;
865 	struct sc27xx_adc_data *sc27xx_data;
866 	const struct sc27xx_adc_variant_data *pdata;
867 	struct iio_dev *indio_dev;
868 	int ret;
869 
870 	pdata = of_device_get_match_data(dev);
871 	if (!pdata) {
872 		dev_err(dev, "No matching driver data found\n");
873 		return -EINVAL;
874 	}
875 
876 	indio_dev = devm_iio_device_alloc(dev, sizeof(*sc27xx_data));
877 	if (!indio_dev)
878 		return -ENOMEM;
879 
880 	sc27xx_data = iio_priv(indio_dev);
881 
882 	sc27xx_data->regmap = dev_get_regmap(dev->parent, NULL);
883 	if (!sc27xx_data->regmap) {
884 		dev_err(dev, "failed to get ADC regmap\n");
885 		return -ENODEV;
886 	}
887 
888 	ret = of_property_read_u32(np, "reg", &sc27xx_data->base);
889 	if (ret) {
890 		dev_err(dev, "failed to get ADC base address\n");
891 		return ret;
892 	}
893 
894 	sc27xx_data->irq = platform_get_irq(pdev, 0);
895 	if (sc27xx_data->irq < 0)
896 		return sc27xx_data->irq;
897 
898 	ret = of_hwspin_lock_get_id(np, 0);
899 	if (ret < 0) {
900 		dev_err(dev, "failed to get hwspinlock id\n");
901 		return ret;
902 	}
903 
904 	sc27xx_data->hwlock = devm_hwspin_lock_request_specific(dev, ret);
905 	if (!sc27xx_data->hwlock) {
906 		dev_err(dev, "failed to request hwspinlock\n");
907 		return -ENXIO;
908 	}
909 
910 	sc27xx_data->dev = dev;
911 	if (pdata->set_volref) {
912 		sc27xx_data->volref = devm_regulator_get(dev, "vref");
913 		if (IS_ERR(sc27xx_data->volref)) {
914 			ret = PTR_ERR(sc27xx_data->volref);
915 			return dev_err_probe(dev, ret, "failed to get ADC volref\n");
916 		}
917 	}
918 
919 	sc27xx_data->var_data = pdata;
920 	sc27xx_data->var_data->init_scale(sc27xx_data);
921 
922 	ret = sc27xx_adc_enable(sc27xx_data);
923 	if (ret) {
924 		dev_err(dev, "failed to enable ADC module\n");
925 		return ret;
926 	}
927 
928 	ret = devm_add_action_or_reset(dev, sc27xx_adc_disable, sc27xx_data);
929 	if (ret) {
930 		dev_err(dev, "failed to add ADC disable action\n");
931 		return ret;
932 	}
933 
934 	indio_dev->name = dev_name(dev);
935 	indio_dev->modes = INDIO_DIRECT_MODE;
936 	indio_dev->info = &sc27xx_info;
937 	indio_dev->channels = sc27xx_channels;
938 	indio_dev->num_channels = ARRAY_SIZE(sc27xx_channels);
939 
940 	mutex_init(&sc27xx_data->lock);
941 
942 	ret = devm_iio_device_register(dev, indio_dev);
943 	if (ret)
944 		dev_err(dev, "could not register iio (ADC)");
945 
946 	return ret;
947 }
948 
949 static const struct of_device_id sc27xx_adc_of_match[] = {
950 	{ .compatible = "sprd,sc2731-adc", .data = &sc2731_data},
951 	{ .compatible = "sprd,sc2730-adc", .data = &sc2730_data},
952 	{ .compatible = "sprd,sc2721-adc", .data = &sc2721_data},
953 	{ .compatible = "sprd,sc2720-adc", .data = &sc2720_data},
954 	{ }
955 };
956 MODULE_DEVICE_TABLE(of, sc27xx_adc_of_match);
957 
958 static struct platform_driver sc27xx_adc_driver = {
959 	.probe = sc27xx_adc_probe,
960 	.driver = {
961 		.name = "sc27xx-adc",
962 		.of_match_table = sc27xx_adc_of_match,
963 	},
964 };
965 
966 module_platform_driver(sc27xx_adc_driver);
967 
968 MODULE_AUTHOR("Freeman Liu <freeman.liu@spreadtrum.com>");
969 MODULE_DESCRIPTION("Spreadtrum SC27XX ADC Driver");
970 MODULE_LICENSE("GPL v2");
971