xref: /openbmc/linux/drivers/iio/adc/meson_saradc.c (revision 82e6fdd6)
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 			return -ETIMEDOUT;
467 	}
468 
469 	return 0;
470 }
471 
472 static void meson_sar_adc_unlock(struct iio_dev *indio_dev)
473 {
474 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
475 
476 	if (priv->data->has_bl30_integration)
477 		/* allow BL30 to use the SAR ADC again */
478 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
479 				MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0);
480 
481 	mutex_unlock(&indio_dev->mlock);
482 }
483 
484 static void meson_sar_adc_clear_fifo(struct iio_dev *indio_dev)
485 {
486 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
487 	unsigned int count, tmp;
488 
489 	for (count = 0; count < MESON_SAR_ADC_MAX_FIFO_SIZE; count++) {
490 		if (!meson_sar_adc_get_fifo_count(indio_dev))
491 			break;
492 
493 		regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &tmp);
494 	}
495 }
496 
497 static int meson_sar_adc_get_sample(struct iio_dev *indio_dev,
498 				    const struct iio_chan_spec *chan,
499 				    enum meson_sar_adc_avg_mode avg_mode,
500 				    enum meson_sar_adc_num_samples avg_samples,
501 				    int *val)
502 {
503 	int ret;
504 
505 	ret = meson_sar_adc_lock(indio_dev);
506 	if (ret)
507 		return ret;
508 
509 	/* clear the FIFO to make sure we're not reading old values */
510 	meson_sar_adc_clear_fifo(indio_dev);
511 
512 	meson_sar_adc_set_averaging(indio_dev, chan, avg_mode, avg_samples);
513 
514 	meson_sar_adc_enable_channel(indio_dev, chan);
515 
516 	meson_sar_adc_start_sample_engine(indio_dev);
517 	ret = meson_sar_adc_read_raw_sample(indio_dev, chan, val);
518 	meson_sar_adc_stop_sample_engine(indio_dev);
519 
520 	meson_sar_adc_unlock(indio_dev);
521 
522 	if (ret) {
523 		dev_warn(indio_dev->dev.parent,
524 			 "failed to read sample for channel %d: %d\n",
525 			 chan->channel, ret);
526 		return ret;
527 	}
528 
529 	return IIO_VAL_INT;
530 }
531 
532 static int meson_sar_adc_iio_info_read_raw(struct iio_dev *indio_dev,
533 					   const struct iio_chan_spec *chan,
534 					   int *val, int *val2, long mask)
535 {
536 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
537 	int ret;
538 
539 	switch (mask) {
540 	case IIO_CHAN_INFO_RAW:
541 		return meson_sar_adc_get_sample(indio_dev, chan, NO_AVERAGING,
542 						ONE_SAMPLE, val);
543 		break;
544 
545 	case IIO_CHAN_INFO_AVERAGE_RAW:
546 		return meson_sar_adc_get_sample(indio_dev, chan,
547 						MEAN_AVERAGING, EIGHT_SAMPLES,
548 						val);
549 		break;
550 
551 	case IIO_CHAN_INFO_SCALE:
552 		ret = regulator_get_voltage(priv->vref);
553 		if (ret < 0) {
554 			dev_err(indio_dev->dev.parent,
555 				"failed to get vref voltage: %d\n", ret);
556 			return ret;
557 		}
558 
559 		*val = ret / 1000;
560 		*val2 = priv->data->resolution;
561 		return IIO_VAL_FRACTIONAL_LOG2;
562 
563 	case IIO_CHAN_INFO_CALIBBIAS:
564 		*val = priv->calibbias;
565 		return IIO_VAL_INT;
566 
567 	case IIO_CHAN_INFO_CALIBSCALE:
568 		*val = priv->calibscale / MILLION;
569 		*val2 = priv->calibscale % MILLION;
570 		return IIO_VAL_INT_PLUS_MICRO;
571 
572 	default:
573 		return -EINVAL;
574 	}
575 }
576 
577 static int meson_sar_adc_clk_init(struct iio_dev *indio_dev,
578 				  void __iomem *base)
579 {
580 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
581 	struct clk_init_data init;
582 	const char *clk_parents[1];
583 
584 	init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%pOF#adc_div",
585 				   indio_dev->dev.of_node);
586 	init.flags = 0;
587 	init.ops = &clk_divider_ops;
588 	clk_parents[0] = __clk_get_name(priv->clkin);
589 	init.parent_names = clk_parents;
590 	init.num_parents = 1;
591 
592 	priv->clk_div.reg = base + MESON_SAR_ADC_REG3;
593 	priv->clk_div.shift = MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT;
594 	priv->clk_div.width = MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH;
595 	priv->clk_div.hw.init = &init;
596 	priv->clk_div.flags = 0;
597 
598 	priv->adc_div_clk = devm_clk_register(&indio_dev->dev,
599 					      &priv->clk_div.hw);
600 	if (WARN_ON(IS_ERR(priv->adc_div_clk)))
601 		return PTR_ERR(priv->adc_div_clk);
602 
603 	init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%pOF#adc_en",
604 				   indio_dev->dev.of_node);
605 	init.flags = CLK_SET_RATE_PARENT;
606 	init.ops = &clk_gate_ops;
607 	clk_parents[0] = __clk_get_name(priv->adc_div_clk);
608 	init.parent_names = clk_parents;
609 	init.num_parents = 1;
610 
611 	priv->clk_gate.reg = base + MESON_SAR_ADC_REG3;
612 	priv->clk_gate.bit_idx = __ffs(MESON_SAR_ADC_REG3_CLK_EN);
613 	priv->clk_gate.hw.init = &init;
614 
615 	priv->adc_clk = devm_clk_register(&indio_dev->dev, &priv->clk_gate.hw);
616 	if (WARN_ON(IS_ERR(priv->adc_clk)))
617 		return PTR_ERR(priv->adc_clk);
618 
619 	return 0;
620 }
621 
622 static int meson_sar_adc_init(struct iio_dev *indio_dev)
623 {
624 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
625 	int regval, i, ret;
626 
627 	/*
628 	 * make sure we start at CH7 input since the other muxes are only used
629 	 * for internal calibration.
630 	 */
631 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
632 
633 	if (priv->data->has_bl30_integration) {
634 		/*
635 		 * leave sampling delay and the input clocks as configured by
636 		 * BL30 to make sure BL30 gets the values it expects when
637 		 * reading the temperature sensor.
638 		 */
639 		regmap_read(priv->regmap, MESON_SAR_ADC_REG3, &regval);
640 		if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED)
641 			return 0;
642 	}
643 
644 	meson_sar_adc_stop_sample_engine(indio_dev);
645 
646 	/* update the channel 6 MUX to select the temperature sensor */
647 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
648 			MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL,
649 			MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL);
650 
651 	/* disable all channels by default */
652 	regmap_write(priv->regmap, MESON_SAR_ADC_CHAN_LIST, 0x0);
653 
654 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
655 			   MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE, 0);
656 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
657 			   MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY,
658 			   MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY);
659 
660 	/* delay between two samples = (10+1) * 1uS */
661 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
662 			   MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
663 			   FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK,
664 				      10));
665 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
666 			   MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
667 			   FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
668 				      0));
669 
670 	/* delay between two samples = (10+1) * 1uS */
671 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
672 			   MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
673 			   FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
674 				      10));
675 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
676 			   MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
677 			   FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
678 				      1));
679 
680 	/*
681 	 * set up the input channel muxes in MESON_SAR_ADC_CHAN_10_SW
682 	 * (0 = SAR_ADC_CH0, 1 = SAR_ADC_CH1)
683 	 */
684 	regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK, 0);
685 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW,
686 			   MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK,
687 			   regval);
688 	regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK, 1);
689 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW,
690 			   MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK,
691 			   regval);
692 
693 	/*
694 	 * set up the input channel muxes in MESON_SAR_ADC_AUX_SW
695 	 * (2 = SAR_ADC_CH2, 3 = SAR_ADC_CH3, ...) and enable
696 	 * MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW and
697 	 * MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW like the vendor driver.
698 	 */
699 	regval = 0;
700 	for (i = 2; i <= 7; i++)
701 		regval |= i << MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(i);
702 	regval |= MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW;
703 	regval |= MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW;
704 	regmap_write(priv->regmap, MESON_SAR_ADC_AUX_SW, regval);
705 
706 	ret = clk_set_parent(priv->adc_sel_clk, priv->clkin);
707 	if (ret) {
708 		dev_err(indio_dev->dev.parent,
709 			"failed to set adc parent to clkin\n");
710 		return ret;
711 	}
712 
713 	ret = clk_set_rate(priv->adc_clk, priv->data->clock_rate);
714 	if (ret) {
715 		dev_err(indio_dev->dev.parent,
716 			"failed to set adc clock rate\n");
717 		return ret;
718 	}
719 
720 	return 0;
721 }
722 
723 static void meson_sar_adc_set_bandgap(struct iio_dev *indio_dev, bool on_off)
724 {
725 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
726 	u32 enable_mask;
727 
728 	if (priv->data->bandgap_reg == MESON_SAR_ADC_REG11)
729 		enable_mask = MESON_SAR_ADC_REG11_BANDGAP_EN;
730 	else
731 		enable_mask = MESON_SAR_ADC_DELTA_10_TS_VBG_EN;
732 
733 	regmap_update_bits(priv->regmap, priv->data->bandgap_reg, enable_mask,
734 			   on_off ? enable_mask : 0);
735 }
736 
737 static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
738 {
739 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
740 	int ret;
741 	u32 regval;
742 
743 	ret = meson_sar_adc_lock(indio_dev);
744 	if (ret)
745 		goto err_lock;
746 
747 	ret = regulator_enable(priv->vref);
748 	if (ret < 0) {
749 		dev_err(indio_dev->dev.parent,
750 			"failed to enable vref regulator\n");
751 		goto err_vref;
752 	}
753 
754 	ret = clk_prepare_enable(priv->core_clk);
755 	if (ret) {
756 		dev_err(indio_dev->dev.parent, "failed to enable core clk\n");
757 		goto err_core_clk;
758 	}
759 
760 	regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1);
761 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
762 			   MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
763 
764 	meson_sar_adc_set_bandgap(indio_dev, true);
765 
766 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
767 			   MESON_SAR_ADC_REG3_ADC_EN,
768 			   MESON_SAR_ADC_REG3_ADC_EN);
769 
770 	udelay(5);
771 
772 	ret = clk_prepare_enable(priv->adc_clk);
773 	if (ret) {
774 		dev_err(indio_dev->dev.parent, "failed to enable adc clk\n");
775 		goto err_adc_clk;
776 	}
777 
778 	meson_sar_adc_unlock(indio_dev);
779 
780 	return 0;
781 
782 err_adc_clk:
783 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
784 			   MESON_SAR_ADC_REG3_ADC_EN, 0);
785 	meson_sar_adc_set_bandgap(indio_dev, false);
786 	clk_disable_unprepare(priv->core_clk);
787 err_core_clk:
788 	regulator_disable(priv->vref);
789 err_vref:
790 	meson_sar_adc_unlock(indio_dev);
791 err_lock:
792 	return ret;
793 }
794 
795 static int meson_sar_adc_hw_disable(struct iio_dev *indio_dev)
796 {
797 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
798 	int ret;
799 
800 	ret = meson_sar_adc_lock(indio_dev);
801 	if (ret)
802 		return ret;
803 
804 	clk_disable_unprepare(priv->adc_clk);
805 
806 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
807 			   MESON_SAR_ADC_REG3_ADC_EN, 0);
808 
809 	meson_sar_adc_set_bandgap(indio_dev, false);
810 
811 	clk_disable_unprepare(priv->core_clk);
812 
813 	regulator_disable(priv->vref);
814 
815 	meson_sar_adc_unlock(indio_dev);
816 
817 	return 0;
818 }
819 
820 static irqreturn_t meson_sar_adc_irq(int irq, void *data)
821 {
822 	struct iio_dev *indio_dev = data;
823 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
824 	unsigned int cnt, threshold;
825 	u32 regval;
826 
827 	regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
828 	cnt = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
829 	threshold = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
830 
831 	if (cnt < threshold)
832 		return IRQ_NONE;
833 
834 	complete(&priv->done);
835 
836 	return IRQ_HANDLED;
837 }
838 
839 static int meson_sar_adc_calib(struct iio_dev *indio_dev)
840 {
841 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
842 	int ret, nominal0, nominal1, value0, value1;
843 
844 	/* use points 25% and 75% for calibration */
845 	nominal0 = (1 << priv->data->resolution) / 4;
846 	nominal1 = (1 << priv->data->resolution) * 3 / 4;
847 
848 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_DIV4);
849 	usleep_range(10, 20);
850 	ret = meson_sar_adc_get_sample(indio_dev,
851 				       &meson_sar_adc_iio_channels[7],
852 				       MEAN_AVERAGING, EIGHT_SAMPLES, &value0);
853 	if (ret < 0)
854 		goto out;
855 
856 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_MUL3_DIV4);
857 	usleep_range(10, 20);
858 	ret = meson_sar_adc_get_sample(indio_dev,
859 				       &meson_sar_adc_iio_channels[7],
860 				       MEAN_AVERAGING, EIGHT_SAMPLES, &value1);
861 	if (ret < 0)
862 		goto out;
863 
864 	if (value1 <= value0) {
865 		ret = -EINVAL;
866 		goto out;
867 	}
868 
869 	priv->calibscale = div_s64((nominal1 - nominal0) * (s64)MILLION,
870 				   value1 - value0);
871 	priv->calibbias = nominal0 - div_s64((s64)value0 * priv->calibscale,
872 					     MILLION);
873 	ret = 0;
874 out:
875 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
876 
877 	return ret;
878 }
879 
880 static const struct iio_info meson_sar_adc_iio_info = {
881 	.read_raw = meson_sar_adc_iio_info_read_raw,
882 };
883 
884 static const struct meson_sar_adc_data meson_sar_adc_meson8_data = {
885 	.has_bl30_integration = false,
886 	.clock_rate = 1150000,
887 	.bandgap_reg = MESON_SAR_ADC_DELTA_10,
888 	.regmap_config = &meson_sar_adc_regmap_config_meson8,
889 	.resolution = 10,
890 	.name = "meson-meson8-saradc",
891 };
892 
893 static const struct meson_sar_adc_data meson_sar_adc_meson8b_data = {
894 	.has_bl30_integration = false,
895 	.clock_rate = 1150000,
896 	.bandgap_reg = MESON_SAR_ADC_DELTA_10,
897 	.regmap_config = &meson_sar_adc_regmap_config_meson8,
898 	.resolution = 10,
899 	.name = "meson-meson8b-saradc",
900 };
901 
902 static const struct meson_sar_adc_data meson_sar_adc_gxbb_data = {
903 	.has_bl30_integration = true,
904 	.clock_rate = 1200000,
905 	.bandgap_reg = MESON_SAR_ADC_REG11,
906 	.regmap_config = &meson_sar_adc_regmap_config_gxbb,
907 	.resolution = 10,
908 	.name = "meson-gxbb-saradc",
909 };
910 
911 static const struct meson_sar_adc_data meson_sar_adc_gxl_data = {
912 	.has_bl30_integration = true,
913 	.clock_rate = 1200000,
914 	.bandgap_reg = MESON_SAR_ADC_REG11,
915 	.regmap_config = &meson_sar_adc_regmap_config_gxbb,
916 	.resolution = 12,
917 	.name = "meson-gxl-saradc",
918 };
919 
920 static const struct meson_sar_adc_data meson_sar_adc_gxm_data = {
921 	.has_bl30_integration = true,
922 	.clock_rate = 1200000,
923 	.bandgap_reg = MESON_SAR_ADC_REG11,
924 	.regmap_config = &meson_sar_adc_regmap_config_gxbb,
925 	.resolution = 12,
926 	.name = "meson-gxm-saradc",
927 };
928 
929 static const struct of_device_id meson_sar_adc_of_match[] = {
930 	{
931 		.compatible = "amlogic,meson8-saradc",
932 		.data = &meson_sar_adc_meson8_data,
933 	},
934 	{
935 		.compatible = "amlogic,meson8b-saradc",
936 		.data = &meson_sar_adc_meson8b_data,
937 	},
938 	{
939 		.compatible = "amlogic,meson-gxbb-saradc",
940 		.data = &meson_sar_adc_gxbb_data,
941 	}, {
942 		.compatible = "amlogic,meson-gxl-saradc",
943 		.data = &meson_sar_adc_gxl_data,
944 	}, {
945 		.compatible = "amlogic,meson-gxm-saradc",
946 		.data = &meson_sar_adc_gxm_data,
947 	},
948 	{},
949 };
950 MODULE_DEVICE_TABLE(of, meson_sar_adc_of_match);
951 
952 static int meson_sar_adc_probe(struct platform_device *pdev)
953 {
954 	struct meson_sar_adc_priv *priv;
955 	struct iio_dev *indio_dev;
956 	struct resource *res;
957 	void __iomem *base;
958 	const struct of_device_id *match;
959 	int irq, ret;
960 
961 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
962 	if (!indio_dev) {
963 		dev_err(&pdev->dev, "failed allocating iio device\n");
964 		return -ENOMEM;
965 	}
966 
967 	priv = iio_priv(indio_dev);
968 	init_completion(&priv->done);
969 
970 	match = of_match_device(meson_sar_adc_of_match, &pdev->dev);
971 	if (!match) {
972 		dev_err(&pdev->dev, "failed to match device\n");
973 		return -ENODEV;
974 	}
975 
976 	priv->data = match->data;
977 
978 	indio_dev->name = priv->data->name;
979 	indio_dev->dev.parent = &pdev->dev;
980 	indio_dev->dev.of_node = pdev->dev.of_node;
981 	indio_dev->modes = INDIO_DIRECT_MODE;
982 	indio_dev->info = &meson_sar_adc_iio_info;
983 
984 	indio_dev->channels = meson_sar_adc_iio_channels;
985 	indio_dev->num_channels = ARRAY_SIZE(meson_sar_adc_iio_channels);
986 
987 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
988 	base = devm_ioremap_resource(&pdev->dev, res);
989 	if (IS_ERR(base))
990 		return PTR_ERR(base);
991 
992 	irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
993 	if (!irq)
994 		return -EINVAL;
995 
996 	ret = devm_request_irq(&pdev->dev, irq, meson_sar_adc_irq, IRQF_SHARED,
997 			       dev_name(&pdev->dev), indio_dev);
998 	if (ret)
999 		return ret;
1000 
1001 	priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
1002 					     priv->data->regmap_config);
1003 	if (IS_ERR(priv->regmap))
1004 		return PTR_ERR(priv->regmap);
1005 
1006 	priv->clkin = devm_clk_get(&pdev->dev, "clkin");
1007 	if (IS_ERR(priv->clkin)) {
1008 		dev_err(&pdev->dev, "failed to get clkin\n");
1009 		return PTR_ERR(priv->clkin);
1010 	}
1011 
1012 	priv->core_clk = devm_clk_get(&pdev->dev, "core");
1013 	if (IS_ERR(priv->core_clk)) {
1014 		dev_err(&pdev->dev, "failed to get core clk\n");
1015 		return PTR_ERR(priv->core_clk);
1016 	}
1017 
1018 	priv->adc_clk = devm_clk_get(&pdev->dev, "adc_clk");
1019 	if (IS_ERR(priv->adc_clk)) {
1020 		if (PTR_ERR(priv->adc_clk) == -ENOENT) {
1021 			priv->adc_clk = NULL;
1022 		} else {
1023 			dev_err(&pdev->dev, "failed to get adc clk\n");
1024 			return PTR_ERR(priv->adc_clk);
1025 		}
1026 	}
1027 
1028 	priv->adc_sel_clk = devm_clk_get(&pdev->dev, "adc_sel");
1029 	if (IS_ERR(priv->adc_sel_clk)) {
1030 		if (PTR_ERR(priv->adc_sel_clk) == -ENOENT) {
1031 			priv->adc_sel_clk = NULL;
1032 		} else {
1033 			dev_err(&pdev->dev, "failed to get adc_sel clk\n");
1034 			return PTR_ERR(priv->adc_sel_clk);
1035 		}
1036 	}
1037 
1038 	/* on pre-GXBB SoCs the SAR ADC itself provides the ADC clock: */
1039 	if (!priv->adc_clk) {
1040 		ret = meson_sar_adc_clk_init(indio_dev, base);
1041 		if (ret)
1042 			return ret;
1043 	}
1044 
1045 	priv->vref = devm_regulator_get(&pdev->dev, "vref");
1046 	if (IS_ERR(priv->vref)) {
1047 		dev_err(&pdev->dev, "failed to get vref regulator\n");
1048 		return PTR_ERR(priv->vref);
1049 	}
1050 
1051 	priv->calibscale = MILLION;
1052 
1053 	ret = meson_sar_adc_init(indio_dev);
1054 	if (ret)
1055 		goto err;
1056 
1057 	ret = meson_sar_adc_hw_enable(indio_dev);
1058 	if (ret)
1059 		goto err;
1060 
1061 	ret = meson_sar_adc_calib(indio_dev);
1062 	if (ret)
1063 		dev_warn(&pdev->dev, "calibration failed\n");
1064 
1065 	platform_set_drvdata(pdev, indio_dev);
1066 
1067 	ret = iio_device_register(indio_dev);
1068 	if (ret)
1069 		goto err_hw;
1070 
1071 	return 0;
1072 
1073 err_hw:
1074 	meson_sar_adc_hw_disable(indio_dev);
1075 err:
1076 	return ret;
1077 }
1078 
1079 static int meson_sar_adc_remove(struct platform_device *pdev)
1080 {
1081 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1082 
1083 	iio_device_unregister(indio_dev);
1084 
1085 	return meson_sar_adc_hw_disable(indio_dev);
1086 }
1087 
1088 static int __maybe_unused meson_sar_adc_suspend(struct device *dev)
1089 {
1090 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
1091 
1092 	return meson_sar_adc_hw_disable(indio_dev);
1093 }
1094 
1095 static int __maybe_unused meson_sar_adc_resume(struct device *dev)
1096 {
1097 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
1098 
1099 	return meson_sar_adc_hw_enable(indio_dev);
1100 }
1101 
1102 static SIMPLE_DEV_PM_OPS(meson_sar_adc_pm_ops,
1103 			 meson_sar_adc_suspend, meson_sar_adc_resume);
1104 
1105 static struct platform_driver meson_sar_adc_driver = {
1106 	.probe		= meson_sar_adc_probe,
1107 	.remove		= meson_sar_adc_remove,
1108 	.driver		= {
1109 		.name	= "meson-saradc",
1110 		.of_match_table = meson_sar_adc_of_match,
1111 		.pm = &meson_sar_adc_pm_ops,
1112 	},
1113 };
1114 
1115 module_platform_driver(meson_sar_adc_driver);
1116 
1117 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
1118 MODULE_DESCRIPTION("Amlogic Meson SAR ADC driver");
1119 MODULE_LICENSE("GPL v2");
1120