xref: /openbmc/linux/drivers/iio/adc/meson_saradc.c (revision a48c7709)
1 /*
2  * Amlogic Meson Successive Approximation Register (SAR) A/D Converter
3  *
4  * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * You should have received a copy of the GNU General Public License
11  * along with this program. If not, see <http://www.gnu.org/licenses/>.
12  */
13 
14 #include <linux/bitfield.h>
15 #include <linux/clk.h>
16 #include <linux/clk-provider.h>
17 #include <linux/delay.h>
18 #include <linux/io.h>
19 #include <linux/iio/iio.h>
20 #include <linux/module.h>
21 #include <linux/interrupt.h>
22 #include <linux/of.h>
23 #include <linux/of_irq.h>
24 #include <linux/of_device.h>
25 #include <linux/platform_device.h>
26 #include <linux/regmap.h>
27 #include <linux/regulator/consumer.h>
28 
29 #define MESON_SAR_ADC_REG0					0x00
30 	#define MESON_SAR_ADC_REG0_PANEL_DETECT			BIT(31)
31 	#define MESON_SAR_ADC_REG0_BUSY_MASK			GENMASK(30, 28)
32 	#define MESON_SAR_ADC_REG0_DELTA_BUSY			BIT(30)
33 	#define MESON_SAR_ADC_REG0_AVG_BUSY			BIT(29)
34 	#define MESON_SAR_ADC_REG0_SAMPLE_BUSY			BIT(28)
35 	#define MESON_SAR_ADC_REG0_FIFO_FULL			BIT(27)
36 	#define MESON_SAR_ADC_REG0_FIFO_EMPTY			BIT(26)
37 	#define MESON_SAR_ADC_REG0_FIFO_COUNT_MASK		GENMASK(25, 21)
38 	#define MESON_SAR_ADC_REG0_ADC_BIAS_CTRL_MASK		GENMASK(20, 19)
39 	#define MESON_SAR_ADC_REG0_CURR_CHAN_ID_MASK		GENMASK(18, 16)
40 	#define MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL		BIT(15)
41 	#define MESON_SAR_ADC_REG0_SAMPLING_STOP		BIT(14)
42 	#define MESON_SAR_ADC_REG0_CHAN_DELTA_EN_MASK		GENMASK(13, 12)
43 	#define MESON_SAR_ADC_REG0_DETECT_IRQ_POL		BIT(10)
44 	#define MESON_SAR_ADC_REG0_DETECT_IRQ_EN		BIT(9)
45 	#define MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK		GENMASK(8, 4)
46 	#define MESON_SAR_ADC_REG0_FIFO_IRQ_EN			BIT(3)
47 	#define MESON_SAR_ADC_REG0_SAMPLING_START		BIT(2)
48 	#define MESON_SAR_ADC_REG0_CONTINUOUS_EN		BIT(1)
49 	#define MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE		BIT(0)
50 
51 #define MESON_SAR_ADC_CHAN_LIST					0x04
52 	#define MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK		GENMASK(26, 24)
53 	#define MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(_chan)	\
54 					(GENMASK(2, 0) << ((_chan) * 3))
55 
56 #define MESON_SAR_ADC_AVG_CNTL					0x08
57 	#define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(_chan)	\
58 					(16 + ((_chan) * 2))
59 	#define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(_chan)	\
60 					(GENMASK(17, 16) << ((_chan) * 2))
61 	#define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(_chan)	\
62 					(0 + ((_chan) * 2))
63 	#define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(_chan)	\
64 					(GENMASK(1, 0) << ((_chan) * 2))
65 
66 #define MESON_SAR_ADC_REG3					0x0c
67 	#define MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY		BIT(31)
68 	#define MESON_SAR_ADC_REG3_CLK_EN			BIT(30)
69 	#define MESON_SAR_ADC_REG3_BL30_INITIALIZED		BIT(28)
70 	#define MESON_SAR_ADC_REG3_CTRL_CONT_RING_COUNTER_EN	BIT(27)
71 	#define MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE	BIT(26)
72 	#define MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK	GENMASK(25, 23)
73 	#define MESON_SAR_ADC_REG3_DETECT_EN			BIT(22)
74 	#define MESON_SAR_ADC_REG3_ADC_EN			BIT(21)
75 	#define MESON_SAR_ADC_REG3_PANEL_DETECT_COUNT_MASK	GENMASK(20, 18)
76 	#define MESON_SAR_ADC_REG3_PANEL_DETECT_FILTER_TB_MASK	GENMASK(17, 16)
77 	#define MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT		10
78 	#define MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH		5
79 	#define MESON_SAR_ADC_REG3_BLOCK_DLY_SEL_MASK		GENMASK(9, 8)
80 	#define MESON_SAR_ADC_REG3_BLOCK_DLY_MASK		GENMASK(7, 0)
81 
82 #define MESON_SAR_ADC_DELAY					0x10
83 	#define MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK		GENMASK(25, 24)
84 	#define MESON_SAR_ADC_DELAY_BL30_BUSY			BIT(15)
85 	#define MESON_SAR_ADC_DELAY_KERNEL_BUSY			BIT(14)
86 	#define MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK		GENMASK(23, 16)
87 	#define MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK		GENMASK(9, 8)
88 	#define MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK		GENMASK(7, 0)
89 
90 #define MESON_SAR_ADC_LAST_RD					0x14
91 	#define MESON_SAR_ADC_LAST_RD_LAST_CHANNEL1_MASK	GENMASK(23, 16)
92 	#define MESON_SAR_ADC_LAST_RD_LAST_CHANNEL0_MASK	GENMASK(9, 0)
93 
94 #define MESON_SAR_ADC_FIFO_RD					0x18
95 	#define MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK		GENMASK(14, 12)
96 	#define MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK		GENMASK(11, 0)
97 
98 #define MESON_SAR_ADC_AUX_SW					0x1c
99 	#define MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(_chan)	\
100 					(8 + (((_chan) - 2) * 3))
101 	#define MESON_SAR_ADC_AUX_SW_VREF_P_MUX			BIT(6)
102 	#define MESON_SAR_ADC_AUX_SW_VREF_N_MUX			BIT(5)
103 	#define MESON_SAR_ADC_AUX_SW_MODE_SEL			BIT(4)
104 	#define MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW		BIT(3)
105 	#define MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW		BIT(2)
106 	#define MESON_SAR_ADC_AUX_SW_YM_DRIVE_SW		BIT(1)
107 	#define MESON_SAR_ADC_AUX_SW_XM_DRIVE_SW		BIT(0)
108 
109 #define MESON_SAR_ADC_CHAN_10_SW				0x20
110 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK	GENMASK(25, 23)
111 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_VREF_P_MUX	BIT(22)
112 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_VREF_N_MUX	BIT(21)
113 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_MODE_SEL		BIT(20)
114 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_YP_DRIVE_SW	BIT(19)
115 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_XP_DRIVE_SW	BIT(18)
116 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_YM_DRIVE_SW	BIT(17)
117 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_XM_DRIVE_SW	BIT(16)
118 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK	GENMASK(9, 7)
119 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_VREF_P_MUX	BIT(6)
120 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_VREF_N_MUX	BIT(5)
121 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_MODE_SEL		BIT(4)
122 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_YP_DRIVE_SW	BIT(3)
123 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_XP_DRIVE_SW	BIT(2)
124 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_YM_DRIVE_SW	BIT(1)
125 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_XM_DRIVE_SW	BIT(0)
126 
127 #define MESON_SAR_ADC_DETECT_IDLE_SW				0x24
128 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_SW_EN	BIT(26)
129 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK	GENMASK(25, 23)
130 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_VREF_P_MUX	BIT(22)
131 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_VREF_N_MUX	BIT(21)
132 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MODE_SEL	BIT(20)
133 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_YP_DRIVE_SW	BIT(19)
134 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_XP_DRIVE_SW	BIT(18)
135 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_YM_DRIVE_SW	BIT(17)
136 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_XM_DRIVE_SW	BIT(16)
137 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK	GENMASK(9, 7)
138 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_VREF_P_MUX	BIT(6)
139 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_VREF_N_MUX	BIT(5)
140 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MODE_SEL	BIT(4)
141 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_YP_DRIVE_SW	BIT(3)
142 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_XP_DRIVE_SW	BIT(2)
143 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_YM_DRIVE_SW	BIT(1)
144 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_XM_DRIVE_SW	BIT(0)
145 
146 #define MESON_SAR_ADC_DELTA_10					0x28
147 	#define MESON_SAR_ADC_DELTA_10_TEMP_SEL			BIT(27)
148 	#define MESON_SAR_ADC_DELTA_10_TS_REVE1			BIT(26)
149 	#define MESON_SAR_ADC_DELTA_10_CHAN1_DELTA_VALUE_MASK	GENMASK(25, 16)
150 	#define MESON_SAR_ADC_DELTA_10_TS_REVE0			BIT(15)
151 	#define MESON_SAR_ADC_DELTA_10_TS_C_SHIFT		11
152 	#define MESON_SAR_ADC_DELTA_10_TS_C_MASK		GENMASK(14, 11)
153 	#define MESON_SAR_ADC_DELTA_10_TS_VBG_EN		BIT(10)
154 	#define MESON_SAR_ADC_DELTA_10_CHAN0_DELTA_VALUE_MASK	GENMASK(9, 0)
155 
156 /*
157  * NOTE: registers from here are undocumented (the vendor Linux kernel driver
158  * and u-boot source served as reference). These only seem to be relevant on
159  * GXBB and newer.
160  */
161 #define MESON_SAR_ADC_REG11					0x2c
162 	#define MESON_SAR_ADC_REG11_BANDGAP_EN			BIT(13)
163 
164 #define MESON_SAR_ADC_REG13					0x34
165 	#define MESON_SAR_ADC_REG13_12BIT_CALIBRATION_MASK	GENMASK(13, 8)
166 
167 #define MESON_SAR_ADC_MAX_FIFO_SIZE				32
168 #define MESON_SAR_ADC_TIMEOUT					100 /* ms */
169 /* for use with IIO_VAL_INT_PLUS_MICRO */
170 #define MILLION							1000000
171 
172 #define MESON_SAR_ADC_CHAN(_chan) {					\
173 	.type = IIO_VOLTAGE,						\
174 	.indexed = 1,							\
175 	.channel = _chan,						\
176 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
177 				BIT(IIO_CHAN_INFO_AVERAGE_RAW),		\
178 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
179 				BIT(IIO_CHAN_INFO_CALIBBIAS) |		\
180 				BIT(IIO_CHAN_INFO_CALIBSCALE),		\
181 	.datasheet_name = "SAR_ADC_CH"#_chan,				\
182 }
183 
184 /*
185  * TODO: the hardware supports IIO_TEMP for channel 6 as well which is
186  * currently not supported by this driver.
187  */
188 static const struct iio_chan_spec meson_sar_adc_iio_channels[] = {
189 	MESON_SAR_ADC_CHAN(0),
190 	MESON_SAR_ADC_CHAN(1),
191 	MESON_SAR_ADC_CHAN(2),
192 	MESON_SAR_ADC_CHAN(3),
193 	MESON_SAR_ADC_CHAN(4),
194 	MESON_SAR_ADC_CHAN(5),
195 	MESON_SAR_ADC_CHAN(6),
196 	MESON_SAR_ADC_CHAN(7),
197 	IIO_CHAN_SOFT_TIMESTAMP(8),
198 };
199 
200 enum meson_sar_adc_avg_mode {
201 	NO_AVERAGING = 0x0,
202 	MEAN_AVERAGING = 0x1,
203 	MEDIAN_AVERAGING = 0x2,
204 };
205 
206 enum meson_sar_adc_num_samples {
207 	ONE_SAMPLE = 0x0,
208 	TWO_SAMPLES = 0x1,
209 	FOUR_SAMPLES = 0x2,
210 	EIGHT_SAMPLES = 0x3,
211 };
212 
213 enum meson_sar_adc_chan7_mux_sel {
214 	CHAN7_MUX_VSS = 0x0,
215 	CHAN7_MUX_VDD_DIV4 = 0x1,
216 	CHAN7_MUX_VDD_DIV2 = 0x2,
217 	CHAN7_MUX_VDD_MUL3_DIV4 = 0x3,
218 	CHAN7_MUX_VDD = 0x4,
219 	CHAN7_MUX_CH7_INPUT = 0x7,
220 };
221 
222 struct meson_sar_adc_data {
223 	bool					has_bl30_integration;
224 	unsigned long				clock_rate;
225 	u32					bandgap_reg;
226 	unsigned int				resolution;
227 	const char				*name;
228 	const struct regmap_config		*regmap_config;
229 };
230 
231 struct meson_sar_adc_priv {
232 	struct regmap				*regmap;
233 	struct regulator			*vref;
234 	const struct meson_sar_adc_data		*data;
235 	struct clk				*clkin;
236 	struct clk				*core_clk;
237 	struct clk				*adc_sel_clk;
238 	struct clk				*adc_clk;
239 	struct clk_gate				clk_gate;
240 	struct clk				*adc_div_clk;
241 	struct clk_divider			clk_div;
242 	struct completion			done;
243 	int					calibbias;
244 	int					calibscale;
245 };
246 
247 static const struct regmap_config meson_sar_adc_regmap_config_gxbb = {
248 	.reg_bits = 8,
249 	.val_bits = 32,
250 	.reg_stride = 4,
251 	.max_register = MESON_SAR_ADC_REG13,
252 };
253 
254 static const struct regmap_config meson_sar_adc_regmap_config_meson8 = {
255 	.reg_bits = 8,
256 	.val_bits = 32,
257 	.reg_stride = 4,
258 	.max_register = MESON_SAR_ADC_DELTA_10,
259 };
260 
261 static unsigned int meson_sar_adc_get_fifo_count(struct iio_dev *indio_dev)
262 {
263 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
264 	u32 regval;
265 
266 	regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
267 
268 	return FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
269 }
270 
271 static int meson_sar_adc_calib_val(struct iio_dev *indio_dev, int val)
272 {
273 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
274 	int tmp;
275 
276 	/* use val_calib = scale * val_raw + offset calibration function */
277 	tmp = div_s64((s64)val * priv->calibscale, MILLION) + priv->calibbias;
278 
279 	return clamp(tmp, 0, (1 << priv->data->resolution) - 1);
280 }
281 
282 static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev)
283 {
284 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
285 	int regval, timeout = 10000;
286 
287 	/*
288 	 * NOTE: we need a small delay before reading the status, otherwise
289 	 * the sample engine may not have started internally (which would
290 	 * seem to us that sampling is already finished).
291 	 */
292 	do {
293 		udelay(1);
294 		regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
295 	} while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--);
296 
297 	if (timeout < 0)
298 		return -ETIMEDOUT;
299 
300 	return 0;
301 }
302 
303 static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
304 					 const struct iio_chan_spec *chan,
305 					 int *val)
306 {
307 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
308 	int regval, fifo_chan, fifo_val, count;
309 
310 	if(!wait_for_completion_timeout(&priv->done,
311 				msecs_to_jiffies(MESON_SAR_ADC_TIMEOUT)))
312 		return -ETIMEDOUT;
313 
314 	count = meson_sar_adc_get_fifo_count(indio_dev);
315 	if (count != 1) {
316 		dev_err(&indio_dev->dev,
317 			"ADC FIFO has %d element(s) instead of one\n", count);
318 		return -EINVAL;
319 	}
320 
321 	regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &regval);
322 	fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval);
323 	if (fifo_chan != chan->channel) {
324 		dev_err(&indio_dev->dev,
325 			"ADC FIFO entry belongs to channel %d instead of %d\n",
326 			fifo_chan, chan->channel);
327 		return -EINVAL;
328 	}
329 
330 	fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK, regval);
331 	fifo_val &= GENMASK(priv->data->resolution - 1, 0);
332 	*val = meson_sar_adc_calib_val(indio_dev, fifo_val);
333 
334 	return 0;
335 }
336 
337 static void meson_sar_adc_set_averaging(struct iio_dev *indio_dev,
338 					const struct iio_chan_spec *chan,
339 					enum meson_sar_adc_avg_mode mode,
340 					enum meson_sar_adc_num_samples samples)
341 {
342 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
343 	int val, channel = chan->channel;
344 
345 	val = samples << MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(channel);
346 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
347 			   MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(channel),
348 			   val);
349 
350 	val = mode << MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(channel);
351 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
352 			   MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(channel), val);
353 }
354 
355 static void meson_sar_adc_enable_channel(struct iio_dev *indio_dev,
356 					const struct iio_chan_spec *chan)
357 {
358 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
359 	u32 regval;
360 
361 	/*
362 	 * the SAR ADC engine allows sampling multiple channels at the same
363 	 * time. to keep it simple we're only working with one *internal*
364 	 * channel, which starts counting at index 0 (which means: count = 1).
365 	 */
366 	regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, 0);
367 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
368 			   MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, regval);
369 
370 	/* map channel index 0 to the channel which we want to read */
371 	regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0),
372 			    chan->channel);
373 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
374 			   MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0), regval);
375 
376 	regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
377 			    chan->channel);
378 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
379 			   MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
380 			   regval);
381 
382 	regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
383 			    chan->channel);
384 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
385 			   MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
386 			   regval);
387 
388 	if (chan->channel == 6)
389 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
390 				   MESON_SAR_ADC_DELTA_10_TEMP_SEL, 0);
391 }
392 
393 static void meson_sar_adc_set_chan7_mux(struct iio_dev *indio_dev,
394 					enum meson_sar_adc_chan7_mux_sel sel)
395 {
396 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
397 	u32 regval;
398 
399 	regval = FIELD_PREP(MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, sel);
400 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
401 			   MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, regval);
402 
403 	usleep_range(10, 20);
404 }
405 
406 static void meson_sar_adc_start_sample_engine(struct iio_dev *indio_dev)
407 {
408 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
409 
410 	reinit_completion(&priv->done);
411 
412 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
413 			   MESON_SAR_ADC_REG0_FIFO_IRQ_EN,
414 			   MESON_SAR_ADC_REG0_FIFO_IRQ_EN);
415 
416 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
417 			   MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE,
418 			   MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE);
419 
420 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
421 			   MESON_SAR_ADC_REG0_SAMPLING_START,
422 			   MESON_SAR_ADC_REG0_SAMPLING_START);
423 }
424 
425 static void meson_sar_adc_stop_sample_engine(struct iio_dev *indio_dev)
426 {
427 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
428 
429 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
430 			   MESON_SAR_ADC_REG0_FIFO_IRQ_EN, 0);
431 
432 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
433 			   MESON_SAR_ADC_REG0_SAMPLING_STOP,
434 			   MESON_SAR_ADC_REG0_SAMPLING_STOP);
435 
436 	/* wait until all modules are stopped */
437 	meson_sar_adc_wait_busy_clear(indio_dev);
438 
439 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
440 			   MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE, 0);
441 }
442 
443 static int meson_sar_adc_lock(struct iio_dev *indio_dev)
444 {
445 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
446 	int val, timeout = 10000;
447 
448 	mutex_lock(&indio_dev->mlock);
449 
450 	if (priv->data->has_bl30_integration) {
451 		/* prevent BL30 from using the SAR ADC while we are using it */
452 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
453 				MESON_SAR_ADC_DELAY_KERNEL_BUSY,
454 				MESON_SAR_ADC_DELAY_KERNEL_BUSY);
455 
456 		/*
457 		 * wait until BL30 releases it's lock (so we can use the SAR
458 		 * ADC)
459 		 */
460 		do {
461 			udelay(1);
462 			regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val);
463 		} while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--);
464 
465 		if (timeout < 0) {
466 			mutex_unlock(&indio_dev->mlock);
467 			return -ETIMEDOUT;
468 		}
469 	}
470 
471 	return 0;
472 }
473 
474 static void meson_sar_adc_unlock(struct iio_dev *indio_dev)
475 {
476 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
477 
478 	if (priv->data->has_bl30_integration)
479 		/* allow BL30 to use the SAR ADC again */
480 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
481 				MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0);
482 
483 	mutex_unlock(&indio_dev->mlock);
484 }
485 
486 static void meson_sar_adc_clear_fifo(struct iio_dev *indio_dev)
487 {
488 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
489 	unsigned int count, tmp;
490 
491 	for (count = 0; count < MESON_SAR_ADC_MAX_FIFO_SIZE; count++) {
492 		if (!meson_sar_adc_get_fifo_count(indio_dev))
493 			break;
494 
495 		regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &tmp);
496 	}
497 }
498 
499 static int meson_sar_adc_get_sample(struct iio_dev *indio_dev,
500 				    const struct iio_chan_spec *chan,
501 				    enum meson_sar_adc_avg_mode avg_mode,
502 				    enum meson_sar_adc_num_samples avg_samples,
503 				    int *val)
504 {
505 	int ret;
506 
507 	ret = meson_sar_adc_lock(indio_dev);
508 	if (ret)
509 		return ret;
510 
511 	/* clear the FIFO to make sure we're not reading old values */
512 	meson_sar_adc_clear_fifo(indio_dev);
513 
514 	meson_sar_adc_set_averaging(indio_dev, chan, avg_mode, avg_samples);
515 
516 	meson_sar_adc_enable_channel(indio_dev, chan);
517 
518 	meson_sar_adc_start_sample_engine(indio_dev);
519 	ret = meson_sar_adc_read_raw_sample(indio_dev, chan, val);
520 	meson_sar_adc_stop_sample_engine(indio_dev);
521 
522 	meson_sar_adc_unlock(indio_dev);
523 
524 	if (ret) {
525 		dev_warn(indio_dev->dev.parent,
526 			 "failed to read sample for channel %d: %d\n",
527 			 chan->channel, ret);
528 		return ret;
529 	}
530 
531 	return IIO_VAL_INT;
532 }
533 
534 static int meson_sar_adc_iio_info_read_raw(struct iio_dev *indio_dev,
535 					   const struct iio_chan_spec *chan,
536 					   int *val, int *val2, long mask)
537 {
538 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
539 	int ret;
540 
541 	switch (mask) {
542 	case IIO_CHAN_INFO_RAW:
543 		return meson_sar_adc_get_sample(indio_dev, chan, NO_AVERAGING,
544 						ONE_SAMPLE, val);
545 		break;
546 
547 	case IIO_CHAN_INFO_AVERAGE_RAW:
548 		return meson_sar_adc_get_sample(indio_dev, chan,
549 						MEAN_AVERAGING, EIGHT_SAMPLES,
550 						val);
551 		break;
552 
553 	case IIO_CHAN_INFO_SCALE:
554 		ret = regulator_get_voltage(priv->vref);
555 		if (ret < 0) {
556 			dev_err(indio_dev->dev.parent,
557 				"failed to get vref voltage: %d\n", ret);
558 			return ret;
559 		}
560 
561 		*val = ret / 1000;
562 		*val2 = priv->data->resolution;
563 		return IIO_VAL_FRACTIONAL_LOG2;
564 
565 	case IIO_CHAN_INFO_CALIBBIAS:
566 		*val = priv->calibbias;
567 		return IIO_VAL_INT;
568 
569 	case IIO_CHAN_INFO_CALIBSCALE:
570 		*val = priv->calibscale / MILLION;
571 		*val2 = priv->calibscale % MILLION;
572 		return IIO_VAL_INT_PLUS_MICRO;
573 
574 	default:
575 		return -EINVAL;
576 	}
577 }
578 
579 static int meson_sar_adc_clk_init(struct iio_dev *indio_dev,
580 				  void __iomem *base)
581 {
582 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
583 	struct clk_init_data init;
584 	const char *clk_parents[1];
585 
586 	init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%pOF#adc_div",
587 				   indio_dev->dev.of_node);
588 	init.flags = 0;
589 	init.ops = &clk_divider_ops;
590 	clk_parents[0] = __clk_get_name(priv->clkin);
591 	init.parent_names = clk_parents;
592 	init.num_parents = 1;
593 
594 	priv->clk_div.reg = base + MESON_SAR_ADC_REG3;
595 	priv->clk_div.shift = MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT;
596 	priv->clk_div.width = MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH;
597 	priv->clk_div.hw.init = &init;
598 	priv->clk_div.flags = 0;
599 
600 	priv->adc_div_clk = devm_clk_register(&indio_dev->dev,
601 					      &priv->clk_div.hw);
602 	if (WARN_ON(IS_ERR(priv->adc_div_clk)))
603 		return PTR_ERR(priv->adc_div_clk);
604 
605 	init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%pOF#adc_en",
606 				   indio_dev->dev.of_node);
607 	init.flags = CLK_SET_RATE_PARENT;
608 	init.ops = &clk_gate_ops;
609 	clk_parents[0] = __clk_get_name(priv->adc_div_clk);
610 	init.parent_names = clk_parents;
611 	init.num_parents = 1;
612 
613 	priv->clk_gate.reg = base + MESON_SAR_ADC_REG3;
614 	priv->clk_gate.bit_idx = __ffs(MESON_SAR_ADC_REG3_CLK_EN);
615 	priv->clk_gate.hw.init = &init;
616 
617 	priv->adc_clk = devm_clk_register(&indio_dev->dev, &priv->clk_gate.hw);
618 	if (WARN_ON(IS_ERR(priv->adc_clk)))
619 		return PTR_ERR(priv->adc_clk);
620 
621 	return 0;
622 }
623 
624 static int meson_sar_adc_init(struct iio_dev *indio_dev)
625 {
626 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
627 	int regval, i, ret;
628 
629 	/*
630 	 * make sure we start at CH7 input since the other muxes are only used
631 	 * for internal calibration.
632 	 */
633 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
634 
635 	if (priv->data->has_bl30_integration) {
636 		/*
637 		 * leave sampling delay and the input clocks as configured by
638 		 * BL30 to make sure BL30 gets the values it expects when
639 		 * reading the temperature sensor.
640 		 */
641 		regmap_read(priv->regmap, MESON_SAR_ADC_REG3, &regval);
642 		if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED)
643 			return 0;
644 	}
645 
646 	meson_sar_adc_stop_sample_engine(indio_dev);
647 
648 	/* update the channel 6 MUX to select the temperature sensor */
649 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
650 			MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL,
651 			MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL);
652 
653 	/* disable all channels by default */
654 	regmap_write(priv->regmap, MESON_SAR_ADC_CHAN_LIST, 0x0);
655 
656 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
657 			   MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE, 0);
658 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
659 			   MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY,
660 			   MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY);
661 
662 	/* delay between two samples = (10+1) * 1uS */
663 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
664 			   MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
665 			   FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK,
666 				      10));
667 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
668 			   MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
669 			   FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
670 				      0));
671 
672 	/* delay between two samples = (10+1) * 1uS */
673 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
674 			   MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
675 			   FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
676 				      10));
677 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
678 			   MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
679 			   FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
680 				      1));
681 
682 	/*
683 	 * set up the input channel muxes in MESON_SAR_ADC_CHAN_10_SW
684 	 * (0 = SAR_ADC_CH0, 1 = SAR_ADC_CH1)
685 	 */
686 	regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK, 0);
687 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW,
688 			   MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK,
689 			   regval);
690 	regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK, 1);
691 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW,
692 			   MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK,
693 			   regval);
694 
695 	/*
696 	 * set up the input channel muxes in MESON_SAR_ADC_AUX_SW
697 	 * (2 = SAR_ADC_CH2, 3 = SAR_ADC_CH3, ...) and enable
698 	 * MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW and
699 	 * MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW like the vendor driver.
700 	 */
701 	regval = 0;
702 	for (i = 2; i <= 7; i++)
703 		regval |= i << MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(i);
704 	regval |= MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW;
705 	regval |= MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW;
706 	regmap_write(priv->regmap, MESON_SAR_ADC_AUX_SW, regval);
707 
708 	ret = clk_set_parent(priv->adc_sel_clk, priv->clkin);
709 	if (ret) {
710 		dev_err(indio_dev->dev.parent,
711 			"failed to set adc parent to clkin\n");
712 		return ret;
713 	}
714 
715 	ret = clk_set_rate(priv->adc_clk, priv->data->clock_rate);
716 	if (ret) {
717 		dev_err(indio_dev->dev.parent,
718 			"failed to set adc clock rate\n");
719 		return ret;
720 	}
721 
722 	return 0;
723 }
724 
725 static void meson_sar_adc_set_bandgap(struct iio_dev *indio_dev, bool on_off)
726 {
727 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
728 	u32 enable_mask;
729 
730 	if (priv->data->bandgap_reg == MESON_SAR_ADC_REG11)
731 		enable_mask = MESON_SAR_ADC_REG11_BANDGAP_EN;
732 	else
733 		enable_mask = MESON_SAR_ADC_DELTA_10_TS_VBG_EN;
734 
735 	regmap_update_bits(priv->regmap, priv->data->bandgap_reg, enable_mask,
736 			   on_off ? enable_mask : 0);
737 }
738 
739 static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
740 {
741 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
742 	int ret;
743 	u32 regval;
744 
745 	ret = meson_sar_adc_lock(indio_dev);
746 	if (ret)
747 		goto err_lock;
748 
749 	ret = regulator_enable(priv->vref);
750 	if (ret < 0) {
751 		dev_err(indio_dev->dev.parent,
752 			"failed to enable vref regulator\n");
753 		goto err_vref;
754 	}
755 
756 	ret = clk_prepare_enable(priv->core_clk);
757 	if (ret) {
758 		dev_err(indio_dev->dev.parent, "failed to enable core clk\n");
759 		goto err_core_clk;
760 	}
761 
762 	regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1);
763 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
764 			   MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
765 
766 	meson_sar_adc_set_bandgap(indio_dev, true);
767 
768 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
769 			   MESON_SAR_ADC_REG3_ADC_EN,
770 			   MESON_SAR_ADC_REG3_ADC_EN);
771 
772 	udelay(5);
773 
774 	ret = clk_prepare_enable(priv->adc_clk);
775 	if (ret) {
776 		dev_err(indio_dev->dev.parent, "failed to enable adc clk\n");
777 		goto err_adc_clk;
778 	}
779 
780 	meson_sar_adc_unlock(indio_dev);
781 
782 	return 0;
783 
784 err_adc_clk:
785 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
786 			   MESON_SAR_ADC_REG3_ADC_EN, 0);
787 	meson_sar_adc_set_bandgap(indio_dev, false);
788 	clk_disable_unprepare(priv->core_clk);
789 err_core_clk:
790 	regulator_disable(priv->vref);
791 err_vref:
792 	meson_sar_adc_unlock(indio_dev);
793 err_lock:
794 	return ret;
795 }
796 
797 static int meson_sar_adc_hw_disable(struct iio_dev *indio_dev)
798 {
799 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
800 	int ret;
801 
802 	ret = meson_sar_adc_lock(indio_dev);
803 	if (ret)
804 		return ret;
805 
806 	clk_disable_unprepare(priv->adc_clk);
807 
808 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
809 			   MESON_SAR_ADC_REG3_ADC_EN, 0);
810 
811 	meson_sar_adc_set_bandgap(indio_dev, false);
812 
813 	clk_disable_unprepare(priv->core_clk);
814 
815 	regulator_disable(priv->vref);
816 
817 	meson_sar_adc_unlock(indio_dev);
818 
819 	return 0;
820 }
821 
822 static irqreturn_t meson_sar_adc_irq(int irq, void *data)
823 {
824 	struct iio_dev *indio_dev = data;
825 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
826 	unsigned int cnt, threshold;
827 	u32 regval;
828 
829 	regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
830 	cnt = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
831 	threshold = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
832 
833 	if (cnt < threshold)
834 		return IRQ_NONE;
835 
836 	complete(&priv->done);
837 
838 	return IRQ_HANDLED;
839 }
840 
841 static int meson_sar_adc_calib(struct iio_dev *indio_dev)
842 {
843 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
844 	int ret, nominal0, nominal1, value0, value1;
845 
846 	/* use points 25% and 75% for calibration */
847 	nominal0 = (1 << priv->data->resolution) / 4;
848 	nominal1 = (1 << priv->data->resolution) * 3 / 4;
849 
850 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_DIV4);
851 	usleep_range(10, 20);
852 	ret = meson_sar_adc_get_sample(indio_dev,
853 				       &meson_sar_adc_iio_channels[7],
854 				       MEAN_AVERAGING, EIGHT_SAMPLES, &value0);
855 	if (ret < 0)
856 		goto out;
857 
858 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_MUL3_DIV4);
859 	usleep_range(10, 20);
860 	ret = meson_sar_adc_get_sample(indio_dev,
861 				       &meson_sar_adc_iio_channels[7],
862 				       MEAN_AVERAGING, EIGHT_SAMPLES, &value1);
863 	if (ret < 0)
864 		goto out;
865 
866 	if (value1 <= value0) {
867 		ret = -EINVAL;
868 		goto out;
869 	}
870 
871 	priv->calibscale = div_s64((nominal1 - nominal0) * (s64)MILLION,
872 				   value1 - value0);
873 	priv->calibbias = nominal0 - div_s64((s64)value0 * priv->calibscale,
874 					     MILLION);
875 	ret = 0;
876 out:
877 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
878 
879 	return ret;
880 }
881 
882 static const struct iio_info meson_sar_adc_iio_info = {
883 	.read_raw = meson_sar_adc_iio_info_read_raw,
884 };
885 
886 static const struct meson_sar_adc_data meson_sar_adc_meson8_data = {
887 	.has_bl30_integration = false,
888 	.clock_rate = 1150000,
889 	.bandgap_reg = MESON_SAR_ADC_DELTA_10,
890 	.regmap_config = &meson_sar_adc_regmap_config_meson8,
891 	.resolution = 10,
892 	.name = "meson-meson8-saradc",
893 };
894 
895 static const struct meson_sar_adc_data meson_sar_adc_meson8b_data = {
896 	.has_bl30_integration = false,
897 	.clock_rate = 1150000,
898 	.bandgap_reg = MESON_SAR_ADC_DELTA_10,
899 	.regmap_config = &meson_sar_adc_regmap_config_meson8,
900 	.resolution = 10,
901 	.name = "meson-meson8b-saradc",
902 };
903 
904 static const struct meson_sar_adc_data meson_sar_adc_gxbb_data = {
905 	.has_bl30_integration = true,
906 	.clock_rate = 1200000,
907 	.bandgap_reg = MESON_SAR_ADC_REG11,
908 	.regmap_config = &meson_sar_adc_regmap_config_gxbb,
909 	.resolution = 10,
910 	.name = "meson-gxbb-saradc",
911 };
912 
913 static const struct meson_sar_adc_data meson_sar_adc_gxl_data = {
914 	.has_bl30_integration = true,
915 	.clock_rate = 1200000,
916 	.bandgap_reg = MESON_SAR_ADC_REG11,
917 	.regmap_config = &meson_sar_adc_regmap_config_gxbb,
918 	.resolution = 12,
919 	.name = "meson-gxl-saradc",
920 };
921 
922 static const struct meson_sar_adc_data meson_sar_adc_gxm_data = {
923 	.has_bl30_integration = true,
924 	.clock_rate = 1200000,
925 	.bandgap_reg = MESON_SAR_ADC_REG11,
926 	.regmap_config = &meson_sar_adc_regmap_config_gxbb,
927 	.resolution = 12,
928 	.name = "meson-gxm-saradc",
929 };
930 
931 static const struct of_device_id meson_sar_adc_of_match[] = {
932 	{
933 		.compatible = "amlogic,meson8-saradc",
934 		.data = &meson_sar_adc_meson8_data,
935 	},
936 	{
937 		.compatible = "amlogic,meson8b-saradc",
938 		.data = &meson_sar_adc_meson8b_data,
939 	},
940 	{
941 		.compatible = "amlogic,meson-gxbb-saradc",
942 		.data = &meson_sar_adc_gxbb_data,
943 	}, {
944 		.compatible = "amlogic,meson-gxl-saradc",
945 		.data = &meson_sar_adc_gxl_data,
946 	}, {
947 		.compatible = "amlogic,meson-gxm-saradc",
948 		.data = &meson_sar_adc_gxm_data,
949 	},
950 	{},
951 };
952 MODULE_DEVICE_TABLE(of, meson_sar_adc_of_match);
953 
954 static int meson_sar_adc_probe(struct platform_device *pdev)
955 {
956 	struct meson_sar_adc_priv *priv;
957 	struct iio_dev *indio_dev;
958 	struct resource *res;
959 	void __iomem *base;
960 	const struct of_device_id *match;
961 	int irq, ret;
962 
963 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
964 	if (!indio_dev) {
965 		dev_err(&pdev->dev, "failed allocating iio device\n");
966 		return -ENOMEM;
967 	}
968 
969 	priv = iio_priv(indio_dev);
970 	init_completion(&priv->done);
971 
972 	match = of_match_device(meson_sar_adc_of_match, &pdev->dev);
973 	if (!match) {
974 		dev_err(&pdev->dev, "failed to match device\n");
975 		return -ENODEV;
976 	}
977 
978 	priv->data = match->data;
979 
980 	indio_dev->name = priv->data->name;
981 	indio_dev->dev.parent = &pdev->dev;
982 	indio_dev->dev.of_node = pdev->dev.of_node;
983 	indio_dev->modes = INDIO_DIRECT_MODE;
984 	indio_dev->info = &meson_sar_adc_iio_info;
985 
986 	indio_dev->channels = meson_sar_adc_iio_channels;
987 	indio_dev->num_channels = ARRAY_SIZE(meson_sar_adc_iio_channels);
988 
989 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
990 	base = devm_ioremap_resource(&pdev->dev, res);
991 	if (IS_ERR(base))
992 		return PTR_ERR(base);
993 
994 	irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
995 	if (!irq)
996 		return -EINVAL;
997 
998 	ret = devm_request_irq(&pdev->dev, irq, meson_sar_adc_irq, IRQF_SHARED,
999 			       dev_name(&pdev->dev), indio_dev);
1000 	if (ret)
1001 		return ret;
1002 
1003 	priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
1004 					     priv->data->regmap_config);
1005 	if (IS_ERR(priv->regmap))
1006 		return PTR_ERR(priv->regmap);
1007 
1008 	priv->clkin = devm_clk_get(&pdev->dev, "clkin");
1009 	if (IS_ERR(priv->clkin)) {
1010 		dev_err(&pdev->dev, "failed to get clkin\n");
1011 		return PTR_ERR(priv->clkin);
1012 	}
1013 
1014 	priv->core_clk = devm_clk_get(&pdev->dev, "core");
1015 	if (IS_ERR(priv->core_clk)) {
1016 		dev_err(&pdev->dev, "failed to get core clk\n");
1017 		return PTR_ERR(priv->core_clk);
1018 	}
1019 
1020 	priv->adc_clk = devm_clk_get(&pdev->dev, "adc_clk");
1021 	if (IS_ERR(priv->adc_clk)) {
1022 		if (PTR_ERR(priv->adc_clk) == -ENOENT) {
1023 			priv->adc_clk = NULL;
1024 		} else {
1025 			dev_err(&pdev->dev, "failed to get adc clk\n");
1026 			return PTR_ERR(priv->adc_clk);
1027 		}
1028 	}
1029 
1030 	priv->adc_sel_clk = devm_clk_get(&pdev->dev, "adc_sel");
1031 	if (IS_ERR(priv->adc_sel_clk)) {
1032 		if (PTR_ERR(priv->adc_sel_clk) == -ENOENT) {
1033 			priv->adc_sel_clk = NULL;
1034 		} else {
1035 			dev_err(&pdev->dev, "failed to get adc_sel clk\n");
1036 			return PTR_ERR(priv->adc_sel_clk);
1037 		}
1038 	}
1039 
1040 	/* on pre-GXBB SoCs the SAR ADC itself provides the ADC clock: */
1041 	if (!priv->adc_clk) {
1042 		ret = meson_sar_adc_clk_init(indio_dev, base);
1043 		if (ret)
1044 			return ret;
1045 	}
1046 
1047 	priv->vref = devm_regulator_get(&pdev->dev, "vref");
1048 	if (IS_ERR(priv->vref)) {
1049 		dev_err(&pdev->dev, "failed to get vref regulator\n");
1050 		return PTR_ERR(priv->vref);
1051 	}
1052 
1053 	priv->calibscale = MILLION;
1054 
1055 	ret = meson_sar_adc_init(indio_dev);
1056 	if (ret)
1057 		goto err;
1058 
1059 	ret = meson_sar_adc_hw_enable(indio_dev);
1060 	if (ret)
1061 		goto err;
1062 
1063 	ret = meson_sar_adc_calib(indio_dev);
1064 	if (ret)
1065 		dev_warn(&pdev->dev, "calibration failed\n");
1066 
1067 	platform_set_drvdata(pdev, indio_dev);
1068 
1069 	ret = iio_device_register(indio_dev);
1070 	if (ret)
1071 		goto err_hw;
1072 
1073 	return 0;
1074 
1075 err_hw:
1076 	meson_sar_adc_hw_disable(indio_dev);
1077 err:
1078 	return ret;
1079 }
1080 
1081 static int meson_sar_adc_remove(struct platform_device *pdev)
1082 {
1083 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1084 
1085 	iio_device_unregister(indio_dev);
1086 
1087 	return meson_sar_adc_hw_disable(indio_dev);
1088 }
1089 
1090 static int __maybe_unused meson_sar_adc_suspend(struct device *dev)
1091 {
1092 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
1093 
1094 	return meson_sar_adc_hw_disable(indio_dev);
1095 }
1096 
1097 static int __maybe_unused meson_sar_adc_resume(struct device *dev)
1098 {
1099 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
1100 
1101 	return meson_sar_adc_hw_enable(indio_dev);
1102 }
1103 
1104 static SIMPLE_DEV_PM_OPS(meson_sar_adc_pm_ops,
1105 			 meson_sar_adc_suspend, meson_sar_adc_resume);
1106 
1107 static struct platform_driver meson_sar_adc_driver = {
1108 	.probe		= meson_sar_adc_probe,
1109 	.remove		= meson_sar_adc_remove,
1110 	.driver		= {
1111 		.name	= "meson-saradc",
1112 		.of_match_table = meson_sar_adc_of_match,
1113 		.pm = &meson_sar_adc_pm_ops,
1114 	},
1115 };
1116 
1117 module_platform_driver(meson_sar_adc_driver);
1118 
1119 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
1120 MODULE_DESCRIPTION("Amlogic Meson SAR ADC driver");
1121 MODULE_LICENSE("GPL v2");
1122