xref: /openbmc/linux/drivers/iio/adc/ingenic-adc.c (revision da1d9caf)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ADC driver for the Ingenic JZ47xx SoCs
4  * Copyright (c) 2019 Artur Rojek <contact@artur-rojek.eu>
5  *
6  * based on drivers/mfd/jz4740-adc.c
7  */
8 
9 #include <dt-bindings/iio/adc/ingenic,adc.h>
10 #include <linux/clk.h>
11 #include <linux/iio/buffer.h>
12 #include <linux/iio/iio.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/iopoll.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/mutex.h>
20 #include <linux/platform_device.h>
21 
22 #define JZ_ADC_REG_ENABLE		0x00
23 #define JZ_ADC_REG_CFG			0x04
24 #define JZ_ADC_REG_CTRL			0x08
25 #define JZ_ADC_REG_STATUS		0x0c
26 #define JZ_ADC_REG_ADSAME		0x10
27 #define JZ_ADC_REG_ADWAIT		0x14
28 #define JZ_ADC_REG_ADTCH		0x18
29 #define JZ_ADC_REG_ADBDAT		0x1c
30 #define JZ_ADC_REG_ADSDAT		0x20
31 #define JZ_ADC_REG_ADCMD		0x24
32 #define JZ_ADC_REG_ADCLK		0x28
33 
34 #define JZ_ADC_REG_ENABLE_PD		BIT(7)
35 #define JZ_ADC_REG_CFG_AUX_MD		(BIT(0) | BIT(1))
36 #define JZ_ADC_REG_CFG_BAT_MD		BIT(4)
37 #define JZ_ADC_REG_CFG_SAMPLE_NUM(n)	((n) << 10)
38 #define JZ_ADC_REG_CFG_PULL_UP(n)	((n) << 16)
39 #define JZ_ADC_REG_CFG_CMD_SEL		BIT(22)
40 #define JZ_ADC_REG_CFG_VBAT_SEL		BIT(30)
41 #define JZ_ADC_REG_CFG_TOUCH_OPS_MASK	(BIT(31) | GENMASK(23, 10))
42 #define JZ_ADC_REG_ADCLK_CLKDIV_LSB	0
43 #define JZ4725B_ADC_REG_ADCLK_CLKDIV10US_LSB	16
44 #define JZ4770_ADC_REG_ADCLK_CLKDIV10US_LSB	8
45 #define JZ4770_ADC_REG_ADCLK_CLKDIVMS_LSB	16
46 
47 #define JZ_ADC_REG_ADCMD_YNADC		BIT(7)
48 #define JZ_ADC_REG_ADCMD_YPADC		BIT(8)
49 #define JZ_ADC_REG_ADCMD_XNADC		BIT(9)
50 #define JZ_ADC_REG_ADCMD_XPADC		BIT(10)
51 #define JZ_ADC_REG_ADCMD_VREFPYP	BIT(11)
52 #define JZ_ADC_REG_ADCMD_VREFPXP	BIT(12)
53 #define JZ_ADC_REG_ADCMD_VREFPXN	BIT(13)
54 #define JZ_ADC_REG_ADCMD_VREFPAUX	BIT(14)
55 #define JZ_ADC_REG_ADCMD_VREFPVDD33	BIT(15)
56 #define JZ_ADC_REG_ADCMD_VREFNYN	BIT(16)
57 #define JZ_ADC_REG_ADCMD_VREFNXP	BIT(17)
58 #define JZ_ADC_REG_ADCMD_VREFNXN	BIT(18)
59 #define JZ_ADC_REG_ADCMD_VREFAUX	BIT(19)
60 #define JZ_ADC_REG_ADCMD_YNGRU		BIT(20)
61 #define JZ_ADC_REG_ADCMD_XNGRU		BIT(21)
62 #define JZ_ADC_REG_ADCMD_XPGRU		BIT(22)
63 #define JZ_ADC_REG_ADCMD_YPSUP		BIT(23)
64 #define JZ_ADC_REG_ADCMD_XNSUP		BIT(24)
65 #define JZ_ADC_REG_ADCMD_XPSUP		BIT(25)
66 
67 #define JZ_ADC_AUX_VREF				3300
68 #define JZ_ADC_AUX_VREF_BITS			12
69 #define JZ_ADC_BATTERY_LOW_VREF			2500
70 #define JZ_ADC_BATTERY_LOW_VREF_BITS		12
71 #define JZ4725B_ADC_BATTERY_HIGH_VREF		7500
72 #define JZ4725B_ADC_BATTERY_HIGH_VREF_BITS	10
73 #define JZ4740_ADC_BATTERY_HIGH_VREF		(7500 * 0.986)
74 #define JZ4740_ADC_BATTERY_HIGH_VREF_BITS	12
75 #define JZ4760_ADC_BATTERY_VREF			2500
76 #define JZ4770_ADC_BATTERY_VREF			1200
77 #define JZ4770_ADC_BATTERY_VREF_BITS		12
78 
79 #define JZ_ADC_IRQ_AUX			BIT(0)
80 #define JZ_ADC_IRQ_BATTERY		BIT(1)
81 #define JZ_ADC_IRQ_TOUCH		BIT(2)
82 #define JZ_ADC_IRQ_PEN_DOWN		BIT(3)
83 #define JZ_ADC_IRQ_PEN_UP		BIT(4)
84 #define JZ_ADC_IRQ_PEN_DOWN_SLEEP	BIT(5)
85 #define JZ_ADC_IRQ_SLEEP		BIT(7)
86 
87 struct ingenic_adc;
88 
89 struct ingenic_adc_soc_data {
90 	unsigned int battery_high_vref;
91 	unsigned int battery_high_vref_bits;
92 	const int *battery_raw_avail;
93 	size_t battery_raw_avail_size;
94 	const int *battery_scale_avail;
95 	size_t battery_scale_avail_size;
96 	unsigned int battery_vref_mode: 1;
97 	unsigned int has_aux_md: 1;
98 	const struct iio_chan_spec *channels;
99 	unsigned int num_channels;
100 	int (*init_clk_div)(struct device *dev, struct ingenic_adc *adc);
101 };
102 
103 struct ingenic_adc {
104 	void __iomem *base;
105 	struct clk *clk;
106 	struct mutex lock;
107 	struct mutex aux_lock;
108 	const struct ingenic_adc_soc_data *soc_data;
109 	bool low_vref_mode;
110 };
111 
112 static void ingenic_adc_set_adcmd(struct iio_dev *iio_dev, unsigned long mask)
113 {
114 	struct ingenic_adc *adc = iio_priv(iio_dev);
115 
116 	mutex_lock(&adc->lock);
117 
118 	/* Init ADCMD */
119 	readl(adc->base + JZ_ADC_REG_ADCMD);
120 
121 	if (mask & 0x3) {
122 		/* Second channel (INGENIC_ADC_TOUCH_YP): sample YP vs. GND */
123 		writel(JZ_ADC_REG_ADCMD_XNGRU
124 		       | JZ_ADC_REG_ADCMD_VREFNXN | JZ_ADC_REG_ADCMD_VREFPVDD33
125 		       | JZ_ADC_REG_ADCMD_YPADC,
126 		       adc->base + JZ_ADC_REG_ADCMD);
127 
128 		/* First channel (INGENIC_ADC_TOUCH_XP): sample XP vs. GND */
129 		writel(JZ_ADC_REG_ADCMD_YNGRU
130 		       | JZ_ADC_REG_ADCMD_VREFNYN | JZ_ADC_REG_ADCMD_VREFPVDD33
131 		       | JZ_ADC_REG_ADCMD_XPADC,
132 		       adc->base + JZ_ADC_REG_ADCMD);
133 	}
134 
135 	if (mask & 0xc) {
136 		/* Fourth channel (INGENIC_ADC_TOUCH_YN): sample YN vs. GND */
137 		writel(JZ_ADC_REG_ADCMD_XNGRU
138 		       | JZ_ADC_REG_ADCMD_VREFNXN | JZ_ADC_REG_ADCMD_VREFPVDD33
139 		       | JZ_ADC_REG_ADCMD_YNADC,
140 		       adc->base + JZ_ADC_REG_ADCMD);
141 
142 		/* Third channel (INGENIC_ADC_TOUCH_XN): sample XN vs. GND */
143 		writel(JZ_ADC_REG_ADCMD_YNGRU
144 		       | JZ_ADC_REG_ADCMD_VREFNYN | JZ_ADC_REG_ADCMD_VREFPVDD33
145 		       | JZ_ADC_REG_ADCMD_XNADC,
146 		       adc->base + JZ_ADC_REG_ADCMD);
147 	}
148 
149 	if (mask & 0x30) {
150 		/* Sixth channel (INGENIC_ADC_TOUCH_YD): sample YP vs. YN */
151 		writel(JZ_ADC_REG_ADCMD_VREFNYN | JZ_ADC_REG_ADCMD_VREFPVDD33
152 		       | JZ_ADC_REG_ADCMD_YPADC,
153 		       adc->base + JZ_ADC_REG_ADCMD);
154 
155 		/* Fifth channel (INGENIC_ADC_TOUCH_XD): sample XP vs. XN */
156 		writel(JZ_ADC_REG_ADCMD_VREFNXN | JZ_ADC_REG_ADCMD_VREFPVDD33
157 		       | JZ_ADC_REG_ADCMD_XPADC,
158 		       adc->base + JZ_ADC_REG_ADCMD);
159 	}
160 
161 	/* We're done */
162 	writel(0, adc->base + JZ_ADC_REG_ADCMD);
163 
164 	mutex_unlock(&adc->lock);
165 }
166 
167 static void ingenic_adc_set_config(struct ingenic_adc *adc,
168 				   uint32_t mask,
169 				   uint32_t val)
170 {
171 	uint32_t cfg;
172 
173 	mutex_lock(&adc->lock);
174 
175 	cfg = readl(adc->base + JZ_ADC_REG_CFG) & ~mask;
176 	cfg |= val;
177 	writel(cfg, adc->base + JZ_ADC_REG_CFG);
178 
179 	mutex_unlock(&adc->lock);
180 }
181 
182 static void ingenic_adc_enable_unlocked(struct ingenic_adc *adc,
183 					int engine,
184 					bool enabled)
185 {
186 	u8 val;
187 
188 	val = readb(adc->base + JZ_ADC_REG_ENABLE);
189 
190 	if (enabled)
191 		val |= BIT(engine);
192 	else
193 		val &= ~BIT(engine);
194 
195 	writeb(val, adc->base + JZ_ADC_REG_ENABLE);
196 }
197 
198 static void ingenic_adc_enable(struct ingenic_adc *adc,
199 			       int engine,
200 			       bool enabled)
201 {
202 	mutex_lock(&adc->lock);
203 	ingenic_adc_enable_unlocked(adc, engine, enabled);
204 	mutex_unlock(&adc->lock);
205 }
206 
207 static int ingenic_adc_capture(struct ingenic_adc *adc,
208 			       int engine)
209 {
210 	u32 cfg;
211 	u8 val;
212 	int ret;
213 
214 	/*
215 	 * Disable CMD_SEL temporarily, because it causes wrong VBAT readings,
216 	 * probably due to the switch of VREF. We must keep the lock here to
217 	 * avoid races with the buffer enable/disable functions.
218 	 */
219 	mutex_lock(&adc->lock);
220 	cfg = readl(adc->base + JZ_ADC_REG_CFG);
221 	writel(cfg & ~JZ_ADC_REG_CFG_CMD_SEL, adc->base + JZ_ADC_REG_CFG);
222 
223 	ingenic_adc_enable_unlocked(adc, engine, true);
224 	ret = readb_poll_timeout(adc->base + JZ_ADC_REG_ENABLE, val,
225 				 !(val & BIT(engine)), 250, 1000);
226 	if (ret)
227 		ingenic_adc_enable_unlocked(adc, engine, false);
228 
229 	writel(cfg, adc->base + JZ_ADC_REG_CFG);
230 	mutex_unlock(&adc->lock);
231 
232 	return ret;
233 }
234 
235 static int ingenic_adc_write_raw(struct iio_dev *iio_dev,
236 				 struct iio_chan_spec const *chan,
237 				 int val,
238 				 int val2,
239 				 long m)
240 {
241 	struct ingenic_adc *adc = iio_priv(iio_dev);
242 	struct device *dev = iio_dev->dev.parent;
243 	int ret;
244 
245 	switch (m) {
246 	case IIO_CHAN_INFO_SCALE:
247 		switch (chan->channel) {
248 		case INGENIC_ADC_BATTERY:
249 			if (!adc->soc_data->battery_vref_mode)
250 				return -EINVAL;
251 
252 			ret = clk_enable(adc->clk);
253 			if (ret) {
254 				dev_err(dev, "Failed to enable clock: %d\n",
255 					ret);
256 				return ret;
257 			}
258 
259 			if (val > JZ_ADC_BATTERY_LOW_VREF) {
260 				ingenic_adc_set_config(adc,
261 						       JZ_ADC_REG_CFG_BAT_MD,
262 						       0);
263 				adc->low_vref_mode = false;
264 			} else {
265 				ingenic_adc_set_config(adc,
266 						       JZ_ADC_REG_CFG_BAT_MD,
267 						       JZ_ADC_REG_CFG_BAT_MD);
268 				adc->low_vref_mode = true;
269 			}
270 
271 			clk_disable(adc->clk);
272 
273 			return 0;
274 		default:
275 			return -EINVAL;
276 		}
277 	default:
278 		return -EINVAL;
279 	}
280 }
281 
282 static const int jz4725b_adc_battery_raw_avail[] = {
283 	0, 1, (1 << JZ_ADC_BATTERY_LOW_VREF_BITS) - 1,
284 };
285 
286 static const int jz4725b_adc_battery_scale_avail[] = {
287 	JZ4725B_ADC_BATTERY_HIGH_VREF, JZ4725B_ADC_BATTERY_HIGH_VREF_BITS,
288 	JZ_ADC_BATTERY_LOW_VREF, JZ_ADC_BATTERY_LOW_VREF_BITS,
289 };
290 
291 static const int jz4740_adc_battery_raw_avail[] = {
292 	0, 1, (1 << JZ_ADC_BATTERY_LOW_VREF_BITS) - 1,
293 };
294 
295 static const int jz4740_adc_battery_scale_avail[] = {
296 	JZ4740_ADC_BATTERY_HIGH_VREF, JZ4740_ADC_BATTERY_HIGH_VREF_BITS,
297 	JZ_ADC_BATTERY_LOW_VREF, JZ_ADC_BATTERY_LOW_VREF_BITS,
298 };
299 
300 static const int jz4760_adc_battery_scale_avail[] = {
301 	JZ4760_ADC_BATTERY_VREF, JZ4770_ADC_BATTERY_VREF_BITS,
302 };
303 
304 static const int jz4770_adc_battery_raw_avail[] = {
305 	0, 1, (1 << JZ4770_ADC_BATTERY_VREF_BITS) - 1,
306 };
307 
308 static const int jz4770_adc_battery_scale_avail[] = {
309 	JZ4770_ADC_BATTERY_VREF, JZ4770_ADC_BATTERY_VREF_BITS,
310 };
311 
312 static int jz4725b_adc_init_clk_div(struct device *dev, struct ingenic_adc *adc)
313 {
314 	struct clk *parent_clk;
315 	unsigned long parent_rate, rate;
316 	unsigned int div_main, div_10us;
317 
318 	parent_clk = clk_get_parent(adc->clk);
319 	if (!parent_clk) {
320 		dev_err(dev, "ADC clock has no parent\n");
321 		return -ENODEV;
322 	}
323 	parent_rate = clk_get_rate(parent_clk);
324 
325 	/*
326 	 * The JZ4725B ADC works at 500 kHz to 8 MHz.
327 	 * We pick the highest rate possible.
328 	 * In practice we typically get 6 MHz, half of the 12 MHz EXT clock.
329 	 */
330 	div_main = DIV_ROUND_UP(parent_rate, 8000000);
331 	div_main = clamp(div_main, 1u, 64u);
332 	rate = parent_rate / div_main;
333 	if (rate < 500000 || rate > 8000000) {
334 		dev_err(dev, "No valid divider for ADC main clock\n");
335 		return -EINVAL;
336 	}
337 
338 	/* We also need a divider that produces a 10us clock. */
339 	div_10us = DIV_ROUND_UP(rate, 100000);
340 
341 	writel(((div_10us - 1) << JZ4725B_ADC_REG_ADCLK_CLKDIV10US_LSB) |
342 	       (div_main - 1) << JZ_ADC_REG_ADCLK_CLKDIV_LSB,
343 	       adc->base + JZ_ADC_REG_ADCLK);
344 
345 	return 0;
346 }
347 
348 static int jz4770_adc_init_clk_div(struct device *dev, struct ingenic_adc *adc)
349 {
350 	struct clk *parent_clk;
351 	unsigned long parent_rate, rate;
352 	unsigned int div_main, div_ms, div_10us;
353 
354 	parent_clk = clk_get_parent(adc->clk);
355 	if (!parent_clk) {
356 		dev_err(dev, "ADC clock has no parent\n");
357 		return -ENODEV;
358 	}
359 	parent_rate = clk_get_rate(parent_clk);
360 
361 	/*
362 	 * The JZ4770 ADC works at 20 kHz to 200 kHz.
363 	 * We pick the highest rate possible.
364 	 */
365 	div_main = DIV_ROUND_UP(parent_rate, 200000);
366 	div_main = clamp(div_main, 1u, 256u);
367 	rate = parent_rate / div_main;
368 	if (rate < 20000 || rate > 200000) {
369 		dev_err(dev, "No valid divider for ADC main clock\n");
370 		return -EINVAL;
371 	}
372 
373 	/* We also need a divider that produces a 10us clock. */
374 	div_10us = DIV_ROUND_UP(rate, 10000);
375 	/* And another, which produces a 1ms clock. */
376 	div_ms = DIV_ROUND_UP(rate, 1000);
377 
378 	writel(((div_ms - 1) << JZ4770_ADC_REG_ADCLK_CLKDIVMS_LSB) |
379 	       ((div_10us - 1) << JZ4770_ADC_REG_ADCLK_CLKDIV10US_LSB) |
380 	       (div_main - 1) << JZ_ADC_REG_ADCLK_CLKDIV_LSB,
381 	       adc->base + JZ_ADC_REG_ADCLK);
382 
383 	return 0;
384 }
385 
386 static const struct iio_chan_spec jz4740_channels[] = {
387 	{
388 		.extend_name = "aux",
389 		.type = IIO_VOLTAGE,
390 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
391 				      BIT(IIO_CHAN_INFO_SCALE),
392 		.indexed = 1,
393 		.channel = INGENIC_ADC_AUX,
394 		.scan_index = -1,
395 	},
396 	{
397 		.extend_name = "battery",
398 		.type = IIO_VOLTAGE,
399 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
400 				      BIT(IIO_CHAN_INFO_SCALE),
401 		.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW) |
402 						BIT(IIO_CHAN_INFO_SCALE),
403 		.indexed = 1,
404 		.channel = INGENIC_ADC_BATTERY,
405 		.scan_index = -1,
406 	},
407 };
408 
409 static const struct iio_chan_spec jz4760_channels[] = {
410 	{
411 		.extend_name = "aux",
412 		.type = IIO_VOLTAGE,
413 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
414 				      BIT(IIO_CHAN_INFO_SCALE),
415 		.indexed = 1,
416 		.channel = INGENIC_ADC_AUX0,
417 		.scan_index = -1,
418 	},
419 	{
420 		.extend_name = "aux1",
421 		.type = IIO_VOLTAGE,
422 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
423 				      BIT(IIO_CHAN_INFO_SCALE),
424 		.indexed = 1,
425 		.channel = INGENIC_ADC_AUX,
426 		.scan_index = -1,
427 	},
428 	{
429 		.extend_name = "aux2",
430 		.type = IIO_VOLTAGE,
431 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
432 				      BIT(IIO_CHAN_INFO_SCALE),
433 		.indexed = 1,
434 		.channel = INGENIC_ADC_AUX2,
435 		.scan_index = -1,
436 	},
437 	{
438 		.extend_name = "battery",
439 		.type = IIO_VOLTAGE,
440 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
441 				      BIT(IIO_CHAN_INFO_SCALE),
442 		.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW) |
443 						BIT(IIO_CHAN_INFO_SCALE),
444 		.indexed = 1,
445 		.channel = INGENIC_ADC_BATTERY,
446 		.scan_index = -1,
447 	},
448 };
449 
450 static const struct iio_chan_spec jz4770_channels[] = {
451 	{
452 		.type = IIO_VOLTAGE,
453 		.indexed = 1,
454 		.channel = INGENIC_ADC_TOUCH_XP,
455 		.scan_index = 0,
456 		.scan_type = {
457 			.sign = 'u',
458 			.realbits = 12,
459 			.storagebits = 16,
460 		},
461 	},
462 	{
463 		.type = IIO_VOLTAGE,
464 		.indexed = 1,
465 		.channel = INGENIC_ADC_TOUCH_YP,
466 		.scan_index = 1,
467 		.scan_type = {
468 			.sign = 'u',
469 			.realbits = 12,
470 			.storagebits = 16,
471 		},
472 	},
473 	{
474 		.type = IIO_VOLTAGE,
475 		.indexed = 1,
476 		.channel = INGENIC_ADC_TOUCH_XN,
477 		.scan_index = 2,
478 		.scan_type = {
479 			.sign = 'u',
480 			.realbits = 12,
481 			.storagebits = 16,
482 		},
483 	},
484 	{
485 		.type = IIO_VOLTAGE,
486 		.indexed = 1,
487 		.channel = INGENIC_ADC_TOUCH_YN,
488 		.scan_index = 3,
489 		.scan_type = {
490 			.sign = 'u',
491 			.realbits = 12,
492 			.storagebits = 16,
493 		},
494 	},
495 	{
496 		.type = IIO_VOLTAGE,
497 		.indexed = 1,
498 		.channel = INGENIC_ADC_TOUCH_XD,
499 		.scan_index = 4,
500 		.scan_type = {
501 			.sign = 'u',
502 			.realbits = 12,
503 			.storagebits = 16,
504 		},
505 	},
506 	{
507 		.type = IIO_VOLTAGE,
508 		.indexed = 1,
509 		.channel = INGENIC_ADC_TOUCH_YD,
510 		.scan_index = 5,
511 		.scan_type = {
512 			.sign = 'u',
513 			.realbits = 12,
514 			.storagebits = 16,
515 		},
516 	},
517 	{
518 		.extend_name = "aux",
519 		.type = IIO_VOLTAGE,
520 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
521 				      BIT(IIO_CHAN_INFO_SCALE),
522 		.indexed = 1,
523 		.channel = INGENIC_ADC_AUX,
524 		.scan_index = -1,
525 	},
526 	{
527 		.extend_name = "battery",
528 		.type = IIO_VOLTAGE,
529 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
530 				      BIT(IIO_CHAN_INFO_SCALE),
531 		.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW) |
532 						BIT(IIO_CHAN_INFO_SCALE),
533 		.indexed = 1,
534 		.channel = INGENIC_ADC_BATTERY,
535 		.scan_index = -1,
536 	},
537 	{
538 		.extend_name = "aux2",
539 		.type = IIO_VOLTAGE,
540 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
541 				      BIT(IIO_CHAN_INFO_SCALE),
542 		.indexed = 1,
543 		.channel = INGENIC_ADC_AUX2,
544 		.scan_index = -1,
545 	},
546 };
547 
548 static const struct ingenic_adc_soc_data jz4725b_adc_soc_data = {
549 	.battery_high_vref = JZ4725B_ADC_BATTERY_HIGH_VREF,
550 	.battery_high_vref_bits = JZ4725B_ADC_BATTERY_HIGH_VREF_BITS,
551 	.battery_raw_avail = jz4725b_adc_battery_raw_avail,
552 	.battery_raw_avail_size = ARRAY_SIZE(jz4725b_adc_battery_raw_avail),
553 	.battery_scale_avail = jz4725b_adc_battery_scale_avail,
554 	.battery_scale_avail_size = ARRAY_SIZE(jz4725b_adc_battery_scale_avail),
555 	.battery_vref_mode = true,
556 	.has_aux_md = false,
557 	.channels = jz4740_channels,
558 	.num_channels = ARRAY_SIZE(jz4740_channels),
559 	.init_clk_div = jz4725b_adc_init_clk_div,
560 };
561 
562 static const struct ingenic_adc_soc_data jz4740_adc_soc_data = {
563 	.battery_high_vref = JZ4740_ADC_BATTERY_HIGH_VREF,
564 	.battery_high_vref_bits = JZ4740_ADC_BATTERY_HIGH_VREF_BITS,
565 	.battery_raw_avail = jz4740_adc_battery_raw_avail,
566 	.battery_raw_avail_size = ARRAY_SIZE(jz4740_adc_battery_raw_avail),
567 	.battery_scale_avail = jz4740_adc_battery_scale_avail,
568 	.battery_scale_avail_size = ARRAY_SIZE(jz4740_adc_battery_scale_avail),
569 	.battery_vref_mode = true,
570 	.has_aux_md = false,
571 	.channels = jz4740_channels,
572 	.num_channels = ARRAY_SIZE(jz4740_channels),
573 	.init_clk_div = NULL, /* no ADCLK register on JZ4740 */
574 };
575 
576 static const struct ingenic_adc_soc_data jz4760_adc_soc_data = {
577 	.battery_high_vref = JZ4760_ADC_BATTERY_VREF,
578 	.battery_high_vref_bits = JZ4770_ADC_BATTERY_VREF_BITS,
579 	.battery_raw_avail = jz4770_adc_battery_raw_avail,
580 	.battery_raw_avail_size = ARRAY_SIZE(jz4770_adc_battery_raw_avail),
581 	.battery_scale_avail = jz4760_adc_battery_scale_avail,
582 	.battery_scale_avail_size = ARRAY_SIZE(jz4760_adc_battery_scale_avail),
583 	.battery_vref_mode = false,
584 	.has_aux_md = true,
585 	.channels = jz4760_channels,
586 	.num_channels = ARRAY_SIZE(jz4760_channels),
587 	.init_clk_div = jz4770_adc_init_clk_div,
588 };
589 
590 static const struct ingenic_adc_soc_data jz4770_adc_soc_data = {
591 	.battery_high_vref = JZ4770_ADC_BATTERY_VREF,
592 	.battery_high_vref_bits = JZ4770_ADC_BATTERY_VREF_BITS,
593 	.battery_raw_avail = jz4770_adc_battery_raw_avail,
594 	.battery_raw_avail_size = ARRAY_SIZE(jz4770_adc_battery_raw_avail),
595 	.battery_scale_avail = jz4770_adc_battery_scale_avail,
596 	.battery_scale_avail_size = ARRAY_SIZE(jz4770_adc_battery_scale_avail),
597 	.battery_vref_mode = false,
598 	.has_aux_md = true,
599 	.channels = jz4770_channels,
600 	.num_channels = ARRAY_SIZE(jz4770_channels),
601 	.init_clk_div = jz4770_adc_init_clk_div,
602 };
603 
604 static int ingenic_adc_read_avail(struct iio_dev *iio_dev,
605 				  struct iio_chan_spec const *chan,
606 				  const int **vals,
607 				  int *type,
608 				  int *length,
609 				  long m)
610 {
611 	struct ingenic_adc *adc = iio_priv(iio_dev);
612 
613 	switch (m) {
614 	case IIO_CHAN_INFO_RAW:
615 		*type = IIO_VAL_INT;
616 		*length = adc->soc_data->battery_raw_avail_size;
617 		*vals = adc->soc_data->battery_raw_avail;
618 		return IIO_AVAIL_RANGE;
619 	case IIO_CHAN_INFO_SCALE:
620 		*type = IIO_VAL_FRACTIONAL_LOG2;
621 		*length = adc->soc_data->battery_scale_avail_size;
622 		*vals = adc->soc_data->battery_scale_avail;
623 		return IIO_AVAIL_LIST;
624 	default:
625 		return -EINVAL;
626 	}
627 }
628 
629 static int ingenic_adc_read_chan_info_raw(struct iio_dev *iio_dev,
630 					  struct iio_chan_spec const *chan,
631 					  int *val)
632 {
633 	int cmd, ret, engine = (chan->channel == INGENIC_ADC_BATTERY);
634 	struct ingenic_adc *adc = iio_priv(iio_dev);
635 
636 	ret = clk_enable(adc->clk);
637 	if (ret) {
638 		dev_err(iio_dev->dev.parent, "Failed to enable clock: %d\n",
639 			ret);
640 		return ret;
641 	}
642 
643 	/* We cannot sample the aux channels in parallel. */
644 	mutex_lock(&adc->aux_lock);
645 	if (adc->soc_data->has_aux_md && engine == 0) {
646 		switch (chan->channel) {
647 		case INGENIC_ADC_AUX0:
648 			cmd = 0;
649 			break;
650 		case INGENIC_ADC_AUX:
651 			cmd = 1;
652 			break;
653 		case INGENIC_ADC_AUX2:
654 			cmd = 2;
655 			break;
656 		}
657 
658 		ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_AUX_MD, cmd);
659 	}
660 
661 	ret = ingenic_adc_capture(adc, engine);
662 	if (ret)
663 		goto out;
664 
665 	switch (chan->channel) {
666 	case INGENIC_ADC_AUX0:
667 	case INGENIC_ADC_AUX:
668 	case INGENIC_ADC_AUX2:
669 		*val = readw(adc->base + JZ_ADC_REG_ADSDAT);
670 		break;
671 	case INGENIC_ADC_BATTERY:
672 		*val = readw(adc->base + JZ_ADC_REG_ADBDAT);
673 		break;
674 	}
675 
676 	ret = IIO_VAL_INT;
677 out:
678 	mutex_unlock(&adc->aux_lock);
679 	clk_disable(adc->clk);
680 
681 	return ret;
682 }
683 
684 static int ingenic_adc_read_raw(struct iio_dev *iio_dev,
685 				struct iio_chan_spec const *chan,
686 				int *val,
687 				int *val2,
688 				long m)
689 {
690 	struct ingenic_adc *adc = iio_priv(iio_dev);
691 
692 	switch (m) {
693 	case IIO_CHAN_INFO_RAW:
694 		return ingenic_adc_read_chan_info_raw(iio_dev, chan, val);
695 	case IIO_CHAN_INFO_SCALE:
696 		switch (chan->channel) {
697 		case INGENIC_ADC_AUX0:
698 		case INGENIC_ADC_AUX:
699 		case INGENIC_ADC_AUX2:
700 			*val = JZ_ADC_AUX_VREF;
701 			*val2 = JZ_ADC_AUX_VREF_BITS;
702 			break;
703 		case INGENIC_ADC_BATTERY:
704 			if (adc->low_vref_mode) {
705 				*val = JZ_ADC_BATTERY_LOW_VREF;
706 				*val2 = JZ_ADC_BATTERY_LOW_VREF_BITS;
707 			} else {
708 				*val = adc->soc_data->battery_high_vref;
709 				*val2 = adc->soc_data->battery_high_vref_bits;
710 			}
711 			break;
712 		}
713 
714 		return IIO_VAL_FRACTIONAL_LOG2;
715 	default:
716 		return -EINVAL;
717 	}
718 }
719 
720 static int ingenic_adc_of_xlate(struct iio_dev *iio_dev,
721 				const struct of_phandle_args *iiospec)
722 {
723 	int i;
724 
725 	if (!iiospec->args_count)
726 		return -EINVAL;
727 
728 	for (i = 0; i < iio_dev->num_channels; ++i)
729 		if (iio_dev->channels[i].channel == iiospec->args[0])
730 			return i;
731 
732 	return -EINVAL;
733 }
734 
735 static void ingenic_adc_clk_cleanup(void *data)
736 {
737 	clk_unprepare(data);
738 }
739 
740 static const struct iio_info ingenic_adc_info = {
741 	.write_raw = ingenic_adc_write_raw,
742 	.read_raw = ingenic_adc_read_raw,
743 	.read_avail = ingenic_adc_read_avail,
744 	.of_xlate = ingenic_adc_of_xlate,
745 };
746 
747 static int ingenic_adc_buffer_enable(struct iio_dev *iio_dev)
748 {
749 	struct ingenic_adc *adc = iio_priv(iio_dev);
750 	int ret;
751 
752 	ret = clk_enable(adc->clk);
753 	if (ret) {
754 		dev_err(iio_dev->dev.parent, "Failed to enable clock: %d\n",
755 			ret);
756 		return ret;
757 	}
758 
759 	/* It takes significant time for the touchscreen hw to stabilize. */
760 	msleep(50);
761 	ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_TOUCH_OPS_MASK,
762 			       JZ_ADC_REG_CFG_SAMPLE_NUM(4) |
763 			       JZ_ADC_REG_CFG_PULL_UP(4));
764 
765 	writew(80, adc->base + JZ_ADC_REG_ADWAIT);
766 	writew(2, adc->base + JZ_ADC_REG_ADSAME);
767 	writeb((u8)~JZ_ADC_IRQ_TOUCH, adc->base + JZ_ADC_REG_CTRL);
768 	writel(0, adc->base + JZ_ADC_REG_ADTCH);
769 
770 	ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_CMD_SEL,
771 			       JZ_ADC_REG_CFG_CMD_SEL);
772 	ingenic_adc_set_adcmd(iio_dev, iio_dev->active_scan_mask[0]);
773 
774 	ingenic_adc_enable(adc, 2, true);
775 
776 	return 0;
777 }
778 
779 static int ingenic_adc_buffer_disable(struct iio_dev *iio_dev)
780 {
781 	struct ingenic_adc *adc = iio_priv(iio_dev);
782 
783 	ingenic_adc_enable(adc, 2, false);
784 
785 	ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_CMD_SEL, 0);
786 
787 	writeb(0xff, adc->base + JZ_ADC_REG_CTRL);
788 	writeb(0xff, adc->base + JZ_ADC_REG_STATUS);
789 	ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_TOUCH_OPS_MASK, 0);
790 	writew(0, adc->base + JZ_ADC_REG_ADSAME);
791 	writew(0, adc->base + JZ_ADC_REG_ADWAIT);
792 	clk_disable(adc->clk);
793 
794 	return 0;
795 }
796 
797 static const struct iio_buffer_setup_ops ingenic_buffer_setup_ops = {
798 	.postenable = &ingenic_adc_buffer_enable,
799 	.predisable = &ingenic_adc_buffer_disable
800 };
801 
802 static irqreturn_t ingenic_adc_irq(int irq, void *data)
803 {
804 	struct iio_dev *iio_dev = data;
805 	struct ingenic_adc *adc = iio_priv(iio_dev);
806 	unsigned long mask = iio_dev->active_scan_mask[0];
807 	unsigned int i;
808 	u32 tdat[3];
809 
810 	for (i = 0; i < ARRAY_SIZE(tdat); mask >>= 2, i++) {
811 		if (mask & 0x3)
812 			tdat[i] = readl(adc->base + JZ_ADC_REG_ADTCH);
813 		else
814 			tdat[i] = 0;
815 	}
816 
817 	iio_push_to_buffers(iio_dev, tdat);
818 	writeb(JZ_ADC_IRQ_TOUCH, adc->base + JZ_ADC_REG_STATUS);
819 
820 	return IRQ_HANDLED;
821 }
822 
823 static int ingenic_adc_probe(struct platform_device *pdev)
824 {
825 	struct device *dev = &pdev->dev;
826 	struct iio_dev *iio_dev;
827 	struct ingenic_adc *adc;
828 	const struct ingenic_adc_soc_data *soc_data;
829 	int irq, ret;
830 
831 	soc_data = device_get_match_data(dev);
832 	if (!soc_data)
833 		return -EINVAL;
834 
835 	iio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
836 	if (!iio_dev)
837 		return -ENOMEM;
838 
839 	adc = iio_priv(iio_dev);
840 	mutex_init(&adc->lock);
841 	mutex_init(&adc->aux_lock);
842 	adc->soc_data = soc_data;
843 
844 	irq = platform_get_irq(pdev, 0);
845 	if (irq < 0)
846 		return irq;
847 
848 	ret = devm_request_irq(dev, irq, ingenic_adc_irq, 0,
849 			       dev_name(dev), iio_dev);
850 	if (ret < 0) {
851 		dev_err(dev, "Failed to request irq: %d\n", ret);
852 		return ret;
853 	}
854 
855 	adc->base = devm_platform_ioremap_resource(pdev, 0);
856 	if (IS_ERR(adc->base))
857 		return PTR_ERR(adc->base);
858 
859 	adc->clk = devm_clk_get(dev, "adc");
860 	if (IS_ERR(adc->clk)) {
861 		dev_err(dev, "Unable to get clock\n");
862 		return PTR_ERR(adc->clk);
863 	}
864 
865 	ret = clk_prepare_enable(adc->clk);
866 	if (ret) {
867 		dev_err(dev, "Failed to enable clock\n");
868 		return ret;
869 	}
870 
871 	/* Set clock dividers. */
872 	if (soc_data->init_clk_div) {
873 		ret = soc_data->init_clk_div(dev, adc);
874 		if (ret) {
875 			clk_disable_unprepare(adc->clk);
876 			return ret;
877 		}
878 	}
879 
880 	/* Put hardware in a known passive state. */
881 	writeb(0x00, adc->base + JZ_ADC_REG_ENABLE);
882 	writeb(0xff, adc->base + JZ_ADC_REG_CTRL);
883 
884 	/* JZ4760B specific */
885 	if (device_property_present(dev, "ingenic,use-internal-divider"))
886 		ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_VBAT_SEL,
887 					    JZ_ADC_REG_CFG_VBAT_SEL);
888 	else
889 		ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_VBAT_SEL, 0);
890 
891 	usleep_range(2000, 3000); /* Must wait at least 2ms. */
892 	clk_disable(adc->clk);
893 
894 	ret = devm_add_action_or_reset(dev, ingenic_adc_clk_cleanup, adc->clk);
895 	if (ret) {
896 		dev_err(dev, "Unable to add action\n");
897 		return ret;
898 	}
899 
900 	iio_dev->name = "jz-adc";
901 	iio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
902 	iio_dev->setup_ops = &ingenic_buffer_setup_ops;
903 	iio_dev->channels = soc_data->channels;
904 	iio_dev->num_channels = soc_data->num_channels;
905 	iio_dev->info = &ingenic_adc_info;
906 
907 	ret = devm_iio_device_register(dev, iio_dev);
908 	if (ret)
909 		dev_err(dev, "Unable to register IIO device\n");
910 
911 	return ret;
912 }
913 
914 static const struct of_device_id ingenic_adc_of_match[] = {
915 	{ .compatible = "ingenic,jz4725b-adc", .data = &jz4725b_adc_soc_data, },
916 	{ .compatible = "ingenic,jz4740-adc", .data = &jz4740_adc_soc_data, },
917 	{ .compatible = "ingenic,jz4760-adc", .data = &jz4760_adc_soc_data, },
918 	{ .compatible = "ingenic,jz4760b-adc", .data = &jz4760_adc_soc_data, },
919 	{ .compatible = "ingenic,jz4770-adc", .data = &jz4770_adc_soc_data, },
920 	{ },
921 };
922 MODULE_DEVICE_TABLE(of, ingenic_adc_of_match);
923 
924 static struct platform_driver ingenic_adc_driver = {
925 	.driver = {
926 		.name = "ingenic-adc",
927 		.of_match_table = ingenic_adc_of_match,
928 	},
929 	.probe = ingenic_adc_probe,
930 };
931 module_platform_driver(ingenic_adc_driver);
932 MODULE_LICENSE("GPL v2");
933