xref: /openbmc/linux/drivers/iio/adc/meson_saradc.c (revision 6e6c61d3)
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/nvmem-consumer.h>
22 #include <linux/interrupt.h>
23 #include <linux/of.h>
24 #include <linux/of_irq.h>
25 #include <linux/of_device.h>
26 #include <linux/platform_device.h>
27 #include <linux/regmap.h>
28 #include <linux/regulator/consumer.h>
29 
30 #define MESON_SAR_ADC_REG0					0x00
31 	#define MESON_SAR_ADC_REG0_PANEL_DETECT			BIT(31)
32 	#define MESON_SAR_ADC_REG0_BUSY_MASK			GENMASK(30, 28)
33 	#define MESON_SAR_ADC_REG0_DELTA_BUSY			BIT(30)
34 	#define MESON_SAR_ADC_REG0_AVG_BUSY			BIT(29)
35 	#define MESON_SAR_ADC_REG0_SAMPLE_BUSY			BIT(28)
36 	#define MESON_SAR_ADC_REG0_FIFO_FULL			BIT(27)
37 	#define MESON_SAR_ADC_REG0_FIFO_EMPTY			BIT(26)
38 	#define MESON_SAR_ADC_REG0_FIFO_COUNT_MASK		GENMASK(25, 21)
39 	#define MESON_SAR_ADC_REG0_ADC_BIAS_CTRL_MASK		GENMASK(20, 19)
40 	#define MESON_SAR_ADC_REG0_CURR_CHAN_ID_MASK		GENMASK(18, 16)
41 	#define MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL		BIT(15)
42 	#define MESON_SAR_ADC_REG0_SAMPLING_STOP		BIT(14)
43 	#define MESON_SAR_ADC_REG0_CHAN_DELTA_EN_MASK		GENMASK(13, 12)
44 	#define MESON_SAR_ADC_REG0_DETECT_IRQ_POL		BIT(10)
45 	#define MESON_SAR_ADC_REG0_DETECT_IRQ_EN		BIT(9)
46 	#define MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK		GENMASK(8, 4)
47 	#define MESON_SAR_ADC_REG0_FIFO_IRQ_EN			BIT(3)
48 	#define MESON_SAR_ADC_REG0_SAMPLING_START		BIT(2)
49 	#define MESON_SAR_ADC_REG0_CONTINUOUS_EN		BIT(1)
50 	#define MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE		BIT(0)
51 
52 #define MESON_SAR_ADC_CHAN_LIST					0x04
53 	#define MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK		GENMASK(26, 24)
54 	#define MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(_chan)	\
55 					(GENMASK(2, 0) << ((_chan) * 3))
56 
57 #define MESON_SAR_ADC_AVG_CNTL					0x08
58 	#define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(_chan)	\
59 					(16 + ((_chan) * 2))
60 	#define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(_chan)	\
61 					(GENMASK(17, 16) << ((_chan) * 2))
62 	#define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(_chan)	\
63 					(0 + ((_chan) * 2))
64 	#define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(_chan)	\
65 					(GENMASK(1, 0) << ((_chan) * 2))
66 
67 #define MESON_SAR_ADC_REG3					0x0c
68 	#define MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY		BIT(31)
69 	#define MESON_SAR_ADC_REG3_CLK_EN			BIT(30)
70 	#define MESON_SAR_ADC_REG3_BL30_INITIALIZED		BIT(28)
71 	#define MESON_SAR_ADC_REG3_CTRL_CONT_RING_COUNTER_EN	BIT(27)
72 	#define MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE	BIT(26)
73 	#define MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK	GENMASK(25, 23)
74 	#define MESON_SAR_ADC_REG3_DETECT_EN			BIT(22)
75 	#define MESON_SAR_ADC_REG3_ADC_EN			BIT(21)
76 	#define MESON_SAR_ADC_REG3_PANEL_DETECT_COUNT_MASK	GENMASK(20, 18)
77 	#define MESON_SAR_ADC_REG3_PANEL_DETECT_FILTER_TB_MASK	GENMASK(17, 16)
78 	#define MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT		10
79 	#define MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH		5
80 	#define MESON_SAR_ADC_REG3_BLOCK_DLY_SEL_MASK		GENMASK(9, 8)
81 	#define MESON_SAR_ADC_REG3_BLOCK_DLY_MASK		GENMASK(7, 0)
82 
83 #define MESON_SAR_ADC_DELAY					0x10
84 	#define MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK		GENMASK(25, 24)
85 	#define MESON_SAR_ADC_DELAY_BL30_BUSY			BIT(15)
86 	#define MESON_SAR_ADC_DELAY_KERNEL_BUSY			BIT(14)
87 	#define MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK		GENMASK(23, 16)
88 	#define MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK		GENMASK(9, 8)
89 	#define MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK		GENMASK(7, 0)
90 
91 #define MESON_SAR_ADC_LAST_RD					0x14
92 	#define MESON_SAR_ADC_LAST_RD_LAST_CHANNEL1_MASK	GENMASK(23, 16)
93 	#define MESON_SAR_ADC_LAST_RD_LAST_CHANNEL0_MASK	GENMASK(9, 0)
94 
95 #define MESON_SAR_ADC_FIFO_RD					0x18
96 	#define MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK		GENMASK(14, 12)
97 	#define MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK		GENMASK(11, 0)
98 
99 #define MESON_SAR_ADC_AUX_SW					0x1c
100 	#define MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(_chan)	\
101 					(8 + (((_chan) - 2) * 3))
102 	#define MESON_SAR_ADC_AUX_SW_VREF_P_MUX			BIT(6)
103 	#define MESON_SAR_ADC_AUX_SW_VREF_N_MUX			BIT(5)
104 	#define MESON_SAR_ADC_AUX_SW_MODE_SEL			BIT(4)
105 	#define MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW		BIT(3)
106 	#define MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW		BIT(2)
107 	#define MESON_SAR_ADC_AUX_SW_YM_DRIVE_SW		BIT(1)
108 	#define MESON_SAR_ADC_AUX_SW_XM_DRIVE_SW		BIT(0)
109 
110 #define MESON_SAR_ADC_CHAN_10_SW				0x20
111 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK	GENMASK(25, 23)
112 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_VREF_P_MUX	BIT(22)
113 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_VREF_N_MUX	BIT(21)
114 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_MODE_SEL		BIT(20)
115 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_YP_DRIVE_SW	BIT(19)
116 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_XP_DRIVE_SW	BIT(18)
117 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_YM_DRIVE_SW	BIT(17)
118 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_XM_DRIVE_SW	BIT(16)
119 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK	GENMASK(9, 7)
120 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_VREF_P_MUX	BIT(6)
121 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_VREF_N_MUX	BIT(5)
122 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_MODE_SEL		BIT(4)
123 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_YP_DRIVE_SW	BIT(3)
124 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_XP_DRIVE_SW	BIT(2)
125 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_YM_DRIVE_SW	BIT(1)
126 	#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_XM_DRIVE_SW	BIT(0)
127 
128 #define MESON_SAR_ADC_DETECT_IDLE_SW				0x24
129 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_SW_EN	BIT(26)
130 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK	GENMASK(25, 23)
131 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_VREF_P_MUX	BIT(22)
132 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_VREF_N_MUX	BIT(21)
133 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MODE_SEL	BIT(20)
134 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_YP_DRIVE_SW	BIT(19)
135 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_XP_DRIVE_SW	BIT(18)
136 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_YM_DRIVE_SW	BIT(17)
137 	#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_XM_DRIVE_SW	BIT(16)
138 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK	GENMASK(9, 7)
139 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_VREF_P_MUX	BIT(6)
140 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_VREF_N_MUX	BIT(5)
141 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MODE_SEL	BIT(4)
142 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_YP_DRIVE_SW	BIT(3)
143 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_XP_DRIVE_SW	BIT(2)
144 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_YM_DRIVE_SW	BIT(1)
145 	#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_XM_DRIVE_SW	BIT(0)
146 
147 #define MESON_SAR_ADC_DELTA_10					0x28
148 	#define MESON_SAR_ADC_DELTA_10_TEMP_SEL			BIT(27)
149 	#define MESON_SAR_ADC_DELTA_10_TS_REVE1			BIT(26)
150 	#define MESON_SAR_ADC_DELTA_10_CHAN1_DELTA_VALUE_MASK	GENMASK(25, 16)
151 	#define MESON_SAR_ADC_DELTA_10_TS_REVE0			BIT(15)
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 #define MESON_SAR_ADC_VOLTAGE_AND_TEMP_CHANNEL			6
170 #define MESON_SAR_ADC_TEMP_OFFSET				27
171 
172 /* temperature sensor calibration information in eFuse */
173 #define MESON_SAR_ADC_EFUSE_BYTES				4
174 #define MESON_SAR_ADC_EFUSE_BYTE3_UPPER_ADC_VAL			GENMASK(6, 0)
175 #define MESON_SAR_ADC_EFUSE_BYTE3_IS_CALIBRATED			BIT(7)
176 
177 /* for use with IIO_VAL_INT_PLUS_MICRO */
178 #define MILLION							1000000
179 
180 #define MESON_SAR_ADC_CHAN(_chan) {					\
181 	.type = IIO_VOLTAGE,						\
182 	.indexed = 1,							\
183 	.channel = _chan,						\
184 	.address = _chan,						\
185 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
186 				BIT(IIO_CHAN_INFO_AVERAGE_RAW),		\
187 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
188 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_CALIBBIAS) |	\
189 				BIT(IIO_CHAN_INFO_CALIBSCALE),		\
190 	.datasheet_name = "SAR_ADC_CH"#_chan,				\
191 }
192 
193 #define MESON_SAR_ADC_TEMP_CHAN(_chan) {				\
194 	.type = IIO_TEMP,						\
195 	.channel = _chan,						\
196 	.address = MESON_SAR_ADC_VOLTAGE_AND_TEMP_CHANNEL,		\
197 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
198 				BIT(IIO_CHAN_INFO_AVERAGE_RAW),		\
199 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |		\
200 					BIT(IIO_CHAN_INFO_SCALE),	\
201 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_CALIBBIAS) |	\
202 				BIT(IIO_CHAN_INFO_CALIBSCALE),		\
203 	.datasheet_name = "TEMP_SENSOR",				\
204 }
205 
206 static const struct iio_chan_spec meson_sar_adc_iio_channels[] = {
207 	MESON_SAR_ADC_CHAN(0),
208 	MESON_SAR_ADC_CHAN(1),
209 	MESON_SAR_ADC_CHAN(2),
210 	MESON_SAR_ADC_CHAN(3),
211 	MESON_SAR_ADC_CHAN(4),
212 	MESON_SAR_ADC_CHAN(5),
213 	MESON_SAR_ADC_CHAN(6),
214 	MESON_SAR_ADC_CHAN(7),
215 	IIO_CHAN_SOFT_TIMESTAMP(8),
216 };
217 
218 static const struct iio_chan_spec meson_sar_adc_and_temp_iio_channels[] = {
219 	MESON_SAR_ADC_CHAN(0),
220 	MESON_SAR_ADC_CHAN(1),
221 	MESON_SAR_ADC_CHAN(2),
222 	MESON_SAR_ADC_CHAN(3),
223 	MESON_SAR_ADC_CHAN(4),
224 	MESON_SAR_ADC_CHAN(5),
225 	MESON_SAR_ADC_CHAN(6),
226 	MESON_SAR_ADC_CHAN(7),
227 	MESON_SAR_ADC_TEMP_CHAN(8),
228 	IIO_CHAN_SOFT_TIMESTAMP(9),
229 };
230 
231 enum meson_sar_adc_avg_mode {
232 	NO_AVERAGING = 0x0,
233 	MEAN_AVERAGING = 0x1,
234 	MEDIAN_AVERAGING = 0x2,
235 };
236 
237 enum meson_sar_adc_num_samples {
238 	ONE_SAMPLE = 0x0,
239 	TWO_SAMPLES = 0x1,
240 	FOUR_SAMPLES = 0x2,
241 	EIGHT_SAMPLES = 0x3,
242 };
243 
244 enum meson_sar_adc_chan7_mux_sel {
245 	CHAN7_MUX_VSS = 0x0,
246 	CHAN7_MUX_VDD_DIV4 = 0x1,
247 	CHAN7_MUX_VDD_DIV2 = 0x2,
248 	CHAN7_MUX_VDD_MUL3_DIV4 = 0x3,
249 	CHAN7_MUX_VDD = 0x4,
250 	CHAN7_MUX_CH7_INPUT = 0x7,
251 };
252 
253 struct meson_sar_adc_param {
254 	bool					has_bl30_integration;
255 	unsigned long				clock_rate;
256 	u32					bandgap_reg;
257 	unsigned int				resolution;
258 	const struct regmap_config		*regmap_config;
259 	u8					temperature_trimming_bits;
260 	unsigned int				temperature_multiplier;
261 	unsigned int				temperature_divider;
262 };
263 
264 struct meson_sar_adc_data {
265 	const struct meson_sar_adc_param	*param;
266 	const char				*name;
267 };
268 
269 struct meson_sar_adc_priv {
270 	struct regmap				*regmap;
271 	struct regulator			*vref;
272 	const struct meson_sar_adc_param	*param;
273 	struct clk				*clkin;
274 	struct clk				*core_clk;
275 	struct clk				*adc_sel_clk;
276 	struct clk				*adc_clk;
277 	struct clk_gate				clk_gate;
278 	struct clk				*adc_div_clk;
279 	struct clk_divider			clk_div;
280 	struct completion			done;
281 	int					calibbias;
282 	int					calibscale;
283 	bool					temperature_sensor_calibrated;
284 	u8					temperature_sensor_coefficient;
285 	u16					temperature_sensor_adc_val;
286 };
287 
288 static const struct regmap_config meson_sar_adc_regmap_config_gxbb = {
289 	.reg_bits = 8,
290 	.val_bits = 32,
291 	.reg_stride = 4,
292 	.max_register = MESON_SAR_ADC_REG13,
293 };
294 
295 static const struct regmap_config meson_sar_adc_regmap_config_meson8 = {
296 	.reg_bits = 8,
297 	.val_bits = 32,
298 	.reg_stride = 4,
299 	.max_register = MESON_SAR_ADC_DELTA_10,
300 };
301 
302 static unsigned int meson_sar_adc_get_fifo_count(struct iio_dev *indio_dev)
303 {
304 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
305 	u32 regval;
306 
307 	regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
308 
309 	return FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
310 }
311 
312 static int meson_sar_adc_calib_val(struct iio_dev *indio_dev, int val)
313 {
314 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
315 	int tmp;
316 
317 	/* use val_calib = scale * val_raw + offset calibration function */
318 	tmp = div_s64((s64)val * priv->calibscale, MILLION) + priv->calibbias;
319 
320 	return clamp(tmp, 0, (1 << priv->param->resolution) - 1);
321 }
322 
323 static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev)
324 {
325 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
326 	int regval, timeout = 10000;
327 
328 	/*
329 	 * NOTE: we need a small delay before reading the status, otherwise
330 	 * the sample engine may not have started internally (which would
331 	 * seem to us that sampling is already finished).
332 	 */
333 	do {
334 		udelay(1);
335 		regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
336 	} while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--);
337 
338 	if (timeout < 0)
339 		return -ETIMEDOUT;
340 
341 	return 0;
342 }
343 
344 static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
345 					 const struct iio_chan_spec *chan,
346 					 int *val)
347 {
348 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
349 	int regval, fifo_chan, fifo_val, count;
350 
351 	if(!wait_for_completion_timeout(&priv->done,
352 				msecs_to_jiffies(MESON_SAR_ADC_TIMEOUT)))
353 		return -ETIMEDOUT;
354 
355 	count = meson_sar_adc_get_fifo_count(indio_dev);
356 	if (count != 1) {
357 		dev_err(&indio_dev->dev,
358 			"ADC FIFO has %d element(s) instead of one\n", count);
359 		return -EINVAL;
360 	}
361 
362 	regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &regval);
363 	fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval);
364 	if (fifo_chan != chan->address) {
365 		dev_err(&indio_dev->dev,
366 			"ADC FIFO entry belongs to channel %d instead of %lu\n",
367 			fifo_chan, chan->address);
368 		return -EINVAL;
369 	}
370 
371 	fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK, regval);
372 	fifo_val &= GENMASK(priv->param->resolution - 1, 0);
373 	*val = meson_sar_adc_calib_val(indio_dev, fifo_val);
374 
375 	return 0;
376 }
377 
378 static void meson_sar_adc_set_averaging(struct iio_dev *indio_dev,
379 					const struct iio_chan_spec *chan,
380 					enum meson_sar_adc_avg_mode mode,
381 					enum meson_sar_adc_num_samples samples)
382 {
383 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
384 	int val, address = chan->address;
385 
386 	val = samples << MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(address);
387 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
388 			   MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(address),
389 			   val);
390 
391 	val = mode << MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(address);
392 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
393 			   MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(address), val);
394 }
395 
396 static void meson_sar_adc_enable_channel(struct iio_dev *indio_dev,
397 					const struct iio_chan_spec *chan)
398 {
399 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
400 	u32 regval;
401 
402 	/*
403 	 * the SAR ADC engine allows sampling multiple channels at the same
404 	 * time. to keep it simple we're only working with one *internal*
405 	 * channel, which starts counting at index 0 (which means: count = 1).
406 	 */
407 	regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, 0);
408 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
409 			   MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, regval);
410 
411 	/* map channel index 0 to the channel which we want to read */
412 	regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0),
413 			    chan->address);
414 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
415 			   MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0), regval);
416 
417 	regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
418 			    chan->address);
419 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
420 			   MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
421 			   regval);
422 
423 	regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
424 			    chan->address);
425 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
426 			   MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
427 			   regval);
428 
429 	if (chan->address == MESON_SAR_ADC_VOLTAGE_AND_TEMP_CHANNEL) {
430 		if (chan->type == IIO_TEMP)
431 			regval = MESON_SAR_ADC_DELTA_10_TEMP_SEL;
432 		else
433 			regval = 0;
434 
435 		regmap_update_bits(priv->regmap,
436 				   MESON_SAR_ADC_DELTA_10,
437 				   MESON_SAR_ADC_DELTA_10_TEMP_SEL, regval);
438 	}
439 }
440 
441 static void meson_sar_adc_set_chan7_mux(struct iio_dev *indio_dev,
442 					enum meson_sar_adc_chan7_mux_sel sel)
443 {
444 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
445 	u32 regval;
446 
447 	regval = FIELD_PREP(MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, sel);
448 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
449 			   MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, regval);
450 
451 	usleep_range(10, 20);
452 }
453 
454 static void meson_sar_adc_start_sample_engine(struct iio_dev *indio_dev)
455 {
456 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
457 
458 	reinit_completion(&priv->done);
459 
460 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
461 			   MESON_SAR_ADC_REG0_FIFO_IRQ_EN,
462 			   MESON_SAR_ADC_REG0_FIFO_IRQ_EN);
463 
464 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
465 			   MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE,
466 			   MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE);
467 
468 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
469 			   MESON_SAR_ADC_REG0_SAMPLING_START,
470 			   MESON_SAR_ADC_REG0_SAMPLING_START);
471 }
472 
473 static void meson_sar_adc_stop_sample_engine(struct iio_dev *indio_dev)
474 {
475 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
476 
477 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
478 			   MESON_SAR_ADC_REG0_FIFO_IRQ_EN, 0);
479 
480 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
481 			   MESON_SAR_ADC_REG0_SAMPLING_STOP,
482 			   MESON_SAR_ADC_REG0_SAMPLING_STOP);
483 
484 	/* wait until all modules are stopped */
485 	meson_sar_adc_wait_busy_clear(indio_dev);
486 
487 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
488 			   MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE, 0);
489 }
490 
491 static int meson_sar_adc_lock(struct iio_dev *indio_dev)
492 {
493 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
494 	int val, timeout = 10000;
495 
496 	mutex_lock(&indio_dev->mlock);
497 
498 	if (priv->param->has_bl30_integration) {
499 		/* prevent BL30 from using the SAR ADC while we are using it */
500 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
501 				MESON_SAR_ADC_DELAY_KERNEL_BUSY,
502 				MESON_SAR_ADC_DELAY_KERNEL_BUSY);
503 
504 		/*
505 		 * wait until BL30 releases it's lock (so we can use the SAR
506 		 * ADC)
507 		 */
508 		do {
509 			udelay(1);
510 			regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val);
511 		} while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--);
512 
513 		if (timeout < 0) {
514 			mutex_unlock(&indio_dev->mlock);
515 			return -ETIMEDOUT;
516 		}
517 	}
518 
519 	return 0;
520 }
521 
522 static void meson_sar_adc_unlock(struct iio_dev *indio_dev)
523 {
524 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
525 
526 	if (priv->param->has_bl30_integration)
527 		/* allow BL30 to use the SAR ADC again */
528 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
529 				MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0);
530 
531 	mutex_unlock(&indio_dev->mlock);
532 }
533 
534 static void meson_sar_adc_clear_fifo(struct iio_dev *indio_dev)
535 {
536 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
537 	unsigned int count, tmp;
538 
539 	for (count = 0; count < MESON_SAR_ADC_MAX_FIFO_SIZE; count++) {
540 		if (!meson_sar_adc_get_fifo_count(indio_dev))
541 			break;
542 
543 		regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &tmp);
544 	}
545 }
546 
547 static int meson_sar_adc_get_sample(struct iio_dev *indio_dev,
548 				    const struct iio_chan_spec *chan,
549 				    enum meson_sar_adc_avg_mode avg_mode,
550 				    enum meson_sar_adc_num_samples avg_samples,
551 				    int *val)
552 {
553 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
554 	int ret;
555 
556 	if (chan->type == IIO_TEMP && !priv->temperature_sensor_calibrated)
557 		return -ENOTSUPP;
558 
559 	ret = meson_sar_adc_lock(indio_dev);
560 	if (ret)
561 		return ret;
562 
563 	/* clear the FIFO to make sure we're not reading old values */
564 	meson_sar_adc_clear_fifo(indio_dev);
565 
566 	meson_sar_adc_set_averaging(indio_dev, chan, avg_mode, avg_samples);
567 
568 	meson_sar_adc_enable_channel(indio_dev, chan);
569 
570 	meson_sar_adc_start_sample_engine(indio_dev);
571 	ret = meson_sar_adc_read_raw_sample(indio_dev, chan, val);
572 	meson_sar_adc_stop_sample_engine(indio_dev);
573 
574 	meson_sar_adc_unlock(indio_dev);
575 
576 	if (ret) {
577 		dev_warn(indio_dev->dev.parent,
578 			 "failed to read sample for channel %lu: %d\n",
579 			 chan->address, ret);
580 		return ret;
581 	}
582 
583 	return IIO_VAL_INT;
584 }
585 
586 static int meson_sar_adc_iio_info_read_raw(struct iio_dev *indio_dev,
587 					   const struct iio_chan_spec *chan,
588 					   int *val, int *val2, long mask)
589 {
590 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
591 	int ret;
592 
593 	switch (mask) {
594 	case IIO_CHAN_INFO_RAW:
595 		return meson_sar_adc_get_sample(indio_dev, chan, NO_AVERAGING,
596 						ONE_SAMPLE, val);
597 		break;
598 
599 	case IIO_CHAN_INFO_AVERAGE_RAW:
600 		return meson_sar_adc_get_sample(indio_dev, chan,
601 						MEAN_AVERAGING, EIGHT_SAMPLES,
602 						val);
603 		break;
604 
605 	case IIO_CHAN_INFO_SCALE:
606 		if (chan->type == IIO_VOLTAGE) {
607 			ret = regulator_get_voltage(priv->vref);
608 			if (ret < 0) {
609 				dev_err(indio_dev->dev.parent,
610 					"failed to get vref voltage: %d\n",
611 					ret);
612 				return ret;
613 			}
614 
615 			*val = ret / 1000;
616 			*val2 = priv->param->resolution;
617 			return IIO_VAL_FRACTIONAL_LOG2;
618 		} else if (chan->type == IIO_TEMP) {
619 			/* SoC specific multiplier and divider */
620 			*val = priv->param->temperature_multiplier;
621 			*val2 = priv->param->temperature_divider;
622 
623 			/* celsius to millicelsius */
624 			*val *= 1000;
625 
626 			return IIO_VAL_FRACTIONAL;
627 		} else {
628 			return -EINVAL;
629 		}
630 
631 	case IIO_CHAN_INFO_CALIBBIAS:
632 		*val = priv->calibbias;
633 		return IIO_VAL_INT;
634 
635 	case IIO_CHAN_INFO_CALIBSCALE:
636 		*val = priv->calibscale / MILLION;
637 		*val2 = priv->calibscale % MILLION;
638 		return IIO_VAL_INT_PLUS_MICRO;
639 
640 	case IIO_CHAN_INFO_OFFSET:
641 		*val = DIV_ROUND_CLOSEST(MESON_SAR_ADC_TEMP_OFFSET *
642 					 priv->param->temperature_divider,
643 					 priv->param->temperature_multiplier);
644 		*val -= priv->temperature_sensor_adc_val;
645 		return IIO_VAL_INT;
646 
647 	default:
648 		return -EINVAL;
649 	}
650 }
651 
652 static int meson_sar_adc_clk_init(struct iio_dev *indio_dev,
653 				  void __iomem *base)
654 {
655 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
656 	struct clk_init_data init;
657 	const char *clk_parents[1];
658 
659 	init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%s#adc_div",
660 				   dev_name(indio_dev->dev.parent));
661 	if (!init.name)
662 		return -ENOMEM;
663 
664 	init.flags = 0;
665 	init.ops = &clk_divider_ops;
666 	clk_parents[0] = __clk_get_name(priv->clkin);
667 	init.parent_names = clk_parents;
668 	init.num_parents = 1;
669 
670 	priv->clk_div.reg = base + MESON_SAR_ADC_REG3;
671 	priv->clk_div.shift = MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT;
672 	priv->clk_div.width = MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH;
673 	priv->clk_div.hw.init = &init;
674 	priv->clk_div.flags = 0;
675 
676 	priv->adc_div_clk = devm_clk_register(&indio_dev->dev,
677 					      &priv->clk_div.hw);
678 	if (WARN_ON(IS_ERR(priv->adc_div_clk)))
679 		return PTR_ERR(priv->adc_div_clk);
680 
681 	init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%s#adc_en",
682 				   dev_name(indio_dev->dev.parent));
683 	if (!init.name)
684 		return -ENOMEM;
685 
686 	init.flags = CLK_SET_RATE_PARENT;
687 	init.ops = &clk_gate_ops;
688 	clk_parents[0] = __clk_get_name(priv->adc_div_clk);
689 	init.parent_names = clk_parents;
690 	init.num_parents = 1;
691 
692 	priv->clk_gate.reg = base + MESON_SAR_ADC_REG3;
693 	priv->clk_gate.bit_idx = __ffs(MESON_SAR_ADC_REG3_CLK_EN);
694 	priv->clk_gate.hw.init = &init;
695 
696 	priv->adc_clk = devm_clk_register(&indio_dev->dev, &priv->clk_gate.hw);
697 	if (WARN_ON(IS_ERR(priv->adc_clk)))
698 		return PTR_ERR(priv->adc_clk);
699 
700 	return 0;
701 }
702 
703 static int meson_sar_adc_temp_sensor_init(struct iio_dev *indio_dev)
704 {
705 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
706 	u8 *buf, trimming_bits, trimming_mask, upper_adc_val;
707 	struct nvmem_cell *temperature_calib;
708 	size_t read_len;
709 	int ret;
710 
711 	temperature_calib = devm_nvmem_cell_get(&indio_dev->dev,
712 						"temperature_calib");
713 	if (IS_ERR(temperature_calib)) {
714 		ret = PTR_ERR(temperature_calib);
715 
716 		/*
717 		 * leave the temperature sensor disabled if no calibration data
718 		 * was passed via nvmem-cells.
719 		 */
720 		if (ret == -ENODEV)
721 			return 0;
722 
723 		if (ret != -EPROBE_DEFER)
724 			dev_err(indio_dev->dev.parent,
725 				"failed to get temperature_calib cell\n");
726 
727 		return ret;
728 	}
729 
730 	read_len = MESON_SAR_ADC_EFUSE_BYTES;
731 	buf = nvmem_cell_read(temperature_calib, &read_len);
732 	if (IS_ERR(buf)) {
733 		dev_err(indio_dev->dev.parent,
734 			"failed to read temperature_calib cell\n");
735 		return PTR_ERR(buf);
736 	} else if (read_len != MESON_SAR_ADC_EFUSE_BYTES) {
737 		kfree(buf);
738 		dev_err(indio_dev->dev.parent,
739 			"invalid read size of temperature_calib cell\n");
740 		return -EINVAL;
741 	}
742 
743 	trimming_bits = priv->param->temperature_trimming_bits;
744 	trimming_mask = BIT(trimming_bits) - 1;
745 
746 	priv->temperature_sensor_calibrated =
747 		buf[3] & MESON_SAR_ADC_EFUSE_BYTE3_IS_CALIBRATED;
748 	priv->temperature_sensor_coefficient = buf[2] & trimming_mask;
749 
750 	upper_adc_val = FIELD_GET(MESON_SAR_ADC_EFUSE_BYTE3_UPPER_ADC_VAL,
751 				  buf[3]);
752 
753 	priv->temperature_sensor_adc_val = buf[2];
754 	priv->temperature_sensor_adc_val |= upper_adc_val << BITS_PER_BYTE;
755 	priv->temperature_sensor_adc_val >>= trimming_bits;
756 
757 	kfree(buf);
758 
759 	return 0;
760 }
761 
762 static int meson_sar_adc_init(struct iio_dev *indio_dev)
763 {
764 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
765 	int regval, i, ret;
766 
767 	/*
768 	 * make sure we start at CH7 input since the other muxes are only used
769 	 * for internal calibration.
770 	 */
771 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
772 
773 	if (priv->param->has_bl30_integration) {
774 		/*
775 		 * leave sampling delay and the input clocks as configured by
776 		 * BL30 to make sure BL30 gets the values it expects when
777 		 * reading the temperature sensor.
778 		 */
779 		regmap_read(priv->regmap, MESON_SAR_ADC_REG3, &regval);
780 		if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED)
781 			return 0;
782 	}
783 
784 	meson_sar_adc_stop_sample_engine(indio_dev);
785 
786 	/*
787 	 * disable this bit as seems to be only relevant for Meson6 (based
788 	 * on the vendor driver), which we don't support at the moment.
789 	 */
790 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
791 			MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL, 0);
792 
793 	/* disable all channels by default */
794 	regmap_write(priv->regmap, MESON_SAR_ADC_CHAN_LIST, 0x0);
795 
796 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
797 			   MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE, 0);
798 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
799 			   MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY,
800 			   MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY);
801 
802 	/* delay between two samples = (10+1) * 1uS */
803 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
804 			   MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
805 			   FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK,
806 				      10));
807 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
808 			   MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
809 			   FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
810 				      0));
811 
812 	/* delay between two samples = (10+1) * 1uS */
813 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
814 			   MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
815 			   FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
816 				      10));
817 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
818 			   MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
819 			   FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
820 				      1));
821 
822 	/*
823 	 * set up the input channel muxes in MESON_SAR_ADC_CHAN_10_SW
824 	 * (0 = SAR_ADC_CH0, 1 = SAR_ADC_CH1)
825 	 */
826 	regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK, 0);
827 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW,
828 			   MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK,
829 			   regval);
830 	regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK, 1);
831 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW,
832 			   MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK,
833 			   regval);
834 
835 	/*
836 	 * set up the input channel muxes in MESON_SAR_ADC_AUX_SW
837 	 * (2 = SAR_ADC_CH2, 3 = SAR_ADC_CH3, ...) and enable
838 	 * MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW and
839 	 * MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW like the vendor driver.
840 	 */
841 	regval = 0;
842 	for (i = 2; i <= 7; i++)
843 		regval |= i << MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(i);
844 	regval |= MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW;
845 	regval |= MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW;
846 	regmap_write(priv->regmap, MESON_SAR_ADC_AUX_SW, regval);
847 
848 	if (priv->temperature_sensor_calibrated) {
849 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
850 				   MESON_SAR_ADC_DELTA_10_TS_REVE1,
851 				   MESON_SAR_ADC_DELTA_10_TS_REVE1);
852 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
853 				   MESON_SAR_ADC_DELTA_10_TS_REVE0,
854 				   MESON_SAR_ADC_DELTA_10_TS_REVE0);
855 
856 		/*
857 		 * set bits [3:0] of the TSC (temperature sensor coefficient)
858 		 * to get the correct values when reading the temperature.
859 		 */
860 		regval = FIELD_PREP(MESON_SAR_ADC_DELTA_10_TS_C_MASK,
861 				    priv->temperature_sensor_coefficient);
862 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
863 				   MESON_SAR_ADC_DELTA_10_TS_C_MASK, regval);
864 	} else {
865 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
866 				   MESON_SAR_ADC_DELTA_10_TS_REVE1, 0);
867 		regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
868 				   MESON_SAR_ADC_DELTA_10_TS_REVE0, 0);
869 	}
870 
871 	ret = clk_set_parent(priv->adc_sel_clk, priv->clkin);
872 	if (ret) {
873 		dev_err(indio_dev->dev.parent,
874 			"failed to set adc parent to clkin\n");
875 		return ret;
876 	}
877 
878 	ret = clk_set_rate(priv->adc_clk, priv->param->clock_rate);
879 	if (ret) {
880 		dev_err(indio_dev->dev.parent,
881 			"failed to set adc clock rate\n");
882 		return ret;
883 	}
884 
885 	return 0;
886 }
887 
888 static void meson_sar_adc_set_bandgap(struct iio_dev *indio_dev, bool on_off)
889 {
890 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
891 	const struct meson_sar_adc_param *param = priv->param;
892 	u32 enable_mask;
893 
894 	if (param->bandgap_reg == MESON_SAR_ADC_REG11)
895 		enable_mask = MESON_SAR_ADC_REG11_BANDGAP_EN;
896 	else
897 		enable_mask = MESON_SAR_ADC_DELTA_10_TS_VBG_EN;
898 
899 	regmap_update_bits(priv->regmap, param->bandgap_reg, enable_mask,
900 			   on_off ? enable_mask : 0);
901 }
902 
903 static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
904 {
905 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
906 	int ret;
907 	u32 regval;
908 
909 	ret = meson_sar_adc_lock(indio_dev);
910 	if (ret)
911 		goto err_lock;
912 
913 	ret = regulator_enable(priv->vref);
914 	if (ret < 0) {
915 		dev_err(indio_dev->dev.parent,
916 			"failed to enable vref regulator\n");
917 		goto err_vref;
918 	}
919 
920 	ret = clk_prepare_enable(priv->core_clk);
921 	if (ret) {
922 		dev_err(indio_dev->dev.parent, "failed to enable core clk\n");
923 		goto err_core_clk;
924 	}
925 
926 	regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1);
927 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
928 			   MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
929 
930 	meson_sar_adc_set_bandgap(indio_dev, true);
931 
932 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
933 			   MESON_SAR_ADC_REG3_ADC_EN,
934 			   MESON_SAR_ADC_REG3_ADC_EN);
935 
936 	udelay(5);
937 
938 	ret = clk_prepare_enable(priv->adc_clk);
939 	if (ret) {
940 		dev_err(indio_dev->dev.parent, "failed to enable adc clk\n");
941 		goto err_adc_clk;
942 	}
943 
944 	meson_sar_adc_unlock(indio_dev);
945 
946 	return 0;
947 
948 err_adc_clk:
949 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
950 			   MESON_SAR_ADC_REG3_ADC_EN, 0);
951 	meson_sar_adc_set_bandgap(indio_dev, false);
952 	clk_disable_unprepare(priv->core_clk);
953 err_core_clk:
954 	regulator_disable(priv->vref);
955 err_vref:
956 	meson_sar_adc_unlock(indio_dev);
957 err_lock:
958 	return ret;
959 }
960 
961 static int meson_sar_adc_hw_disable(struct iio_dev *indio_dev)
962 {
963 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
964 	int ret;
965 
966 	ret = meson_sar_adc_lock(indio_dev);
967 	if (ret)
968 		return ret;
969 
970 	clk_disable_unprepare(priv->adc_clk);
971 
972 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
973 			   MESON_SAR_ADC_REG3_ADC_EN, 0);
974 
975 	meson_sar_adc_set_bandgap(indio_dev, false);
976 
977 	clk_disable_unprepare(priv->core_clk);
978 
979 	regulator_disable(priv->vref);
980 
981 	meson_sar_adc_unlock(indio_dev);
982 
983 	return 0;
984 }
985 
986 static irqreturn_t meson_sar_adc_irq(int irq, void *data)
987 {
988 	struct iio_dev *indio_dev = data;
989 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
990 	unsigned int cnt, threshold;
991 	u32 regval;
992 
993 	regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
994 	cnt = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
995 	threshold = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
996 
997 	if (cnt < threshold)
998 		return IRQ_NONE;
999 
1000 	complete(&priv->done);
1001 
1002 	return IRQ_HANDLED;
1003 }
1004 
1005 static int meson_sar_adc_calib(struct iio_dev *indio_dev)
1006 {
1007 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
1008 	int ret, nominal0, nominal1, value0, value1;
1009 
1010 	/* use points 25% and 75% for calibration */
1011 	nominal0 = (1 << priv->param->resolution) / 4;
1012 	nominal1 = (1 << priv->param->resolution) * 3 / 4;
1013 
1014 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_DIV4);
1015 	usleep_range(10, 20);
1016 	ret = meson_sar_adc_get_sample(indio_dev,
1017 				       &indio_dev->channels[7],
1018 				       MEAN_AVERAGING, EIGHT_SAMPLES, &value0);
1019 	if (ret < 0)
1020 		goto out;
1021 
1022 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_MUL3_DIV4);
1023 	usleep_range(10, 20);
1024 	ret = meson_sar_adc_get_sample(indio_dev,
1025 				       &indio_dev->channels[7],
1026 				       MEAN_AVERAGING, EIGHT_SAMPLES, &value1);
1027 	if (ret < 0)
1028 		goto out;
1029 
1030 	if (value1 <= value0) {
1031 		ret = -EINVAL;
1032 		goto out;
1033 	}
1034 
1035 	priv->calibscale = div_s64((nominal1 - nominal0) * (s64)MILLION,
1036 				   value1 - value0);
1037 	priv->calibbias = nominal0 - div_s64((s64)value0 * priv->calibscale,
1038 					     MILLION);
1039 	ret = 0;
1040 out:
1041 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
1042 
1043 	return ret;
1044 }
1045 
1046 static const struct iio_info meson_sar_adc_iio_info = {
1047 	.read_raw = meson_sar_adc_iio_info_read_raw,
1048 };
1049 
1050 static const struct meson_sar_adc_param meson_sar_adc_meson8_param = {
1051 	.has_bl30_integration = false,
1052 	.clock_rate = 1150000,
1053 	.bandgap_reg = MESON_SAR_ADC_DELTA_10,
1054 	.regmap_config = &meson_sar_adc_regmap_config_meson8,
1055 	.resolution = 10,
1056 	.temperature_trimming_bits = 4,
1057 	.temperature_multiplier = 18 * 10000,
1058 	.temperature_divider = 1024 * 10 * 85,
1059 };
1060 
1061 static const struct meson_sar_adc_param meson_sar_adc_meson8b_param = {
1062 	.has_bl30_integration = false,
1063 	.clock_rate = 1150000,
1064 	.bandgap_reg = MESON_SAR_ADC_DELTA_10,
1065 	.regmap_config = &meson_sar_adc_regmap_config_meson8,
1066 	.resolution = 10,
1067 };
1068 
1069 static const struct meson_sar_adc_param meson_sar_adc_gxbb_param = {
1070 	.has_bl30_integration = true,
1071 	.clock_rate = 1200000,
1072 	.bandgap_reg = MESON_SAR_ADC_REG11,
1073 	.regmap_config = &meson_sar_adc_regmap_config_gxbb,
1074 	.resolution = 10,
1075 };
1076 
1077 static const struct meson_sar_adc_param meson_sar_adc_gxl_param = {
1078 	.has_bl30_integration = true,
1079 	.clock_rate = 1200000,
1080 	.bandgap_reg = MESON_SAR_ADC_REG11,
1081 	.regmap_config = &meson_sar_adc_regmap_config_gxbb,
1082 	.resolution = 12,
1083 };
1084 
1085 static const struct meson_sar_adc_data meson_sar_adc_meson8_data = {
1086 	.param = &meson_sar_adc_meson8_param,
1087 	.name = "meson-meson8-saradc",
1088 };
1089 
1090 static const struct meson_sar_adc_data meson_sar_adc_meson8b_data = {
1091 	.param = &meson_sar_adc_meson8b_param,
1092 	.name = "meson-meson8b-saradc",
1093 };
1094 
1095 static const struct meson_sar_adc_data meson_sar_adc_meson8m2_data = {
1096 	.param = &meson_sar_adc_meson8b_param,
1097 	.name = "meson-meson8m2-saradc",
1098 };
1099 
1100 static const struct meson_sar_adc_data meson_sar_adc_gxbb_data = {
1101 	.param = &meson_sar_adc_gxbb_param,
1102 	.name = "meson-gxbb-saradc",
1103 };
1104 
1105 static const struct meson_sar_adc_data meson_sar_adc_gxl_data = {
1106 	.param = &meson_sar_adc_gxl_param,
1107 	.name = "meson-gxl-saradc",
1108 };
1109 
1110 static const struct meson_sar_adc_data meson_sar_adc_gxm_data = {
1111 	.param = &meson_sar_adc_gxl_param,
1112 	.name = "meson-gxm-saradc",
1113 };
1114 
1115 static const struct meson_sar_adc_data meson_sar_adc_axg_data = {
1116 	.param = &meson_sar_adc_gxl_param,
1117 	.name = "meson-axg-saradc",
1118 };
1119 
1120 static const struct of_device_id meson_sar_adc_of_match[] = {
1121 	{
1122 		.compatible = "amlogic,meson8-saradc",
1123 		.data = &meson_sar_adc_meson8_data,
1124 	},
1125 	{
1126 		.compatible = "amlogic,meson8b-saradc",
1127 		.data = &meson_sar_adc_meson8b_data,
1128 	},
1129 	{
1130 		.compatible = "amlogic,meson8m2-saradc",
1131 		.data = &meson_sar_adc_meson8m2_data,
1132 	},
1133 	{
1134 		.compatible = "amlogic,meson-gxbb-saradc",
1135 		.data = &meson_sar_adc_gxbb_data,
1136 	}, {
1137 		.compatible = "amlogic,meson-gxl-saradc",
1138 		.data = &meson_sar_adc_gxl_data,
1139 	}, {
1140 		.compatible = "amlogic,meson-gxm-saradc",
1141 		.data = &meson_sar_adc_gxm_data,
1142 	}, {
1143 		.compatible = "amlogic,meson-axg-saradc",
1144 		.data = &meson_sar_adc_axg_data,
1145 	},
1146 	{},
1147 };
1148 MODULE_DEVICE_TABLE(of, meson_sar_adc_of_match);
1149 
1150 static int meson_sar_adc_probe(struct platform_device *pdev)
1151 {
1152 	const struct meson_sar_adc_data *match_data;
1153 	struct meson_sar_adc_priv *priv;
1154 	struct iio_dev *indio_dev;
1155 	struct resource *res;
1156 	void __iomem *base;
1157 	int irq, ret;
1158 
1159 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
1160 	if (!indio_dev) {
1161 		dev_err(&pdev->dev, "failed allocating iio device\n");
1162 		return -ENOMEM;
1163 	}
1164 
1165 	priv = iio_priv(indio_dev);
1166 	init_completion(&priv->done);
1167 
1168 	match_data = of_device_get_match_data(&pdev->dev);
1169 	if (!match_data) {
1170 		dev_err(&pdev->dev, "failed to get match data\n");
1171 		return -ENODEV;
1172 	}
1173 
1174 	priv->param = match_data->param;
1175 
1176 	indio_dev->name = match_data->name;
1177 	indio_dev->dev.parent = &pdev->dev;
1178 	indio_dev->dev.of_node = pdev->dev.of_node;
1179 	indio_dev->modes = INDIO_DIRECT_MODE;
1180 	indio_dev->info = &meson_sar_adc_iio_info;
1181 
1182 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1183 	base = devm_ioremap_resource(&pdev->dev, res);
1184 	if (IS_ERR(base))
1185 		return PTR_ERR(base);
1186 
1187 	irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
1188 	if (!irq)
1189 		return -EINVAL;
1190 
1191 	ret = devm_request_irq(&pdev->dev, irq, meson_sar_adc_irq, IRQF_SHARED,
1192 			       dev_name(&pdev->dev), indio_dev);
1193 	if (ret)
1194 		return ret;
1195 
1196 	priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
1197 					     priv->param->regmap_config);
1198 	if (IS_ERR(priv->regmap))
1199 		return PTR_ERR(priv->regmap);
1200 
1201 	priv->clkin = devm_clk_get(&pdev->dev, "clkin");
1202 	if (IS_ERR(priv->clkin)) {
1203 		dev_err(&pdev->dev, "failed to get clkin\n");
1204 		return PTR_ERR(priv->clkin);
1205 	}
1206 
1207 	priv->core_clk = devm_clk_get(&pdev->dev, "core");
1208 	if (IS_ERR(priv->core_clk)) {
1209 		dev_err(&pdev->dev, "failed to get core clk\n");
1210 		return PTR_ERR(priv->core_clk);
1211 	}
1212 
1213 	priv->adc_clk = devm_clk_get(&pdev->dev, "adc_clk");
1214 	if (IS_ERR(priv->adc_clk)) {
1215 		if (PTR_ERR(priv->adc_clk) == -ENOENT) {
1216 			priv->adc_clk = NULL;
1217 		} else {
1218 			dev_err(&pdev->dev, "failed to get adc clk\n");
1219 			return PTR_ERR(priv->adc_clk);
1220 		}
1221 	}
1222 
1223 	priv->adc_sel_clk = devm_clk_get(&pdev->dev, "adc_sel");
1224 	if (IS_ERR(priv->adc_sel_clk)) {
1225 		if (PTR_ERR(priv->adc_sel_clk) == -ENOENT) {
1226 			priv->adc_sel_clk = NULL;
1227 		} else {
1228 			dev_err(&pdev->dev, "failed to get adc_sel clk\n");
1229 			return PTR_ERR(priv->adc_sel_clk);
1230 		}
1231 	}
1232 
1233 	/* on pre-GXBB SoCs the SAR ADC itself provides the ADC clock: */
1234 	if (!priv->adc_clk) {
1235 		ret = meson_sar_adc_clk_init(indio_dev, base);
1236 		if (ret)
1237 			return ret;
1238 	}
1239 
1240 	priv->vref = devm_regulator_get(&pdev->dev, "vref");
1241 	if (IS_ERR(priv->vref)) {
1242 		dev_err(&pdev->dev, "failed to get vref regulator\n");
1243 		return PTR_ERR(priv->vref);
1244 	}
1245 
1246 	priv->calibscale = MILLION;
1247 
1248 	if (priv->param->temperature_trimming_bits) {
1249 		ret = meson_sar_adc_temp_sensor_init(indio_dev);
1250 		if (ret)
1251 			return ret;
1252 	}
1253 
1254 	if (priv->temperature_sensor_calibrated) {
1255 		indio_dev->channels = meson_sar_adc_and_temp_iio_channels;
1256 		indio_dev->num_channels =
1257 			ARRAY_SIZE(meson_sar_adc_and_temp_iio_channels);
1258 	} else {
1259 		indio_dev->channels = meson_sar_adc_iio_channels;
1260 		indio_dev->num_channels =
1261 			ARRAY_SIZE(meson_sar_adc_iio_channels);
1262 	}
1263 
1264 	ret = meson_sar_adc_init(indio_dev);
1265 	if (ret)
1266 		goto err;
1267 
1268 	ret = meson_sar_adc_hw_enable(indio_dev);
1269 	if (ret)
1270 		goto err;
1271 
1272 	ret = meson_sar_adc_calib(indio_dev);
1273 	if (ret)
1274 		dev_warn(&pdev->dev, "calibration failed\n");
1275 
1276 	platform_set_drvdata(pdev, indio_dev);
1277 
1278 	ret = iio_device_register(indio_dev);
1279 	if (ret)
1280 		goto err_hw;
1281 
1282 	return 0;
1283 
1284 err_hw:
1285 	meson_sar_adc_hw_disable(indio_dev);
1286 err:
1287 	return ret;
1288 }
1289 
1290 static int meson_sar_adc_remove(struct platform_device *pdev)
1291 {
1292 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1293 
1294 	iio_device_unregister(indio_dev);
1295 
1296 	return meson_sar_adc_hw_disable(indio_dev);
1297 }
1298 
1299 static int __maybe_unused meson_sar_adc_suspend(struct device *dev)
1300 {
1301 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
1302 
1303 	return meson_sar_adc_hw_disable(indio_dev);
1304 }
1305 
1306 static int __maybe_unused meson_sar_adc_resume(struct device *dev)
1307 {
1308 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
1309 
1310 	return meson_sar_adc_hw_enable(indio_dev);
1311 }
1312 
1313 static SIMPLE_DEV_PM_OPS(meson_sar_adc_pm_ops,
1314 			 meson_sar_adc_suspend, meson_sar_adc_resume);
1315 
1316 static struct platform_driver meson_sar_adc_driver = {
1317 	.probe		= meson_sar_adc_probe,
1318 	.remove		= meson_sar_adc_remove,
1319 	.driver		= {
1320 		.name	= "meson-saradc",
1321 		.of_match_table = meson_sar_adc_of_match,
1322 		.pm = &meson_sar_adc_pm_ops,
1323 	},
1324 };
1325 
1326 module_platform_driver(meson_sar_adc_driver);
1327 
1328 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
1329 MODULE_DESCRIPTION("Amlogic Meson SAR ADC driver");
1330 MODULE_LICENSE("GPL v2");
1331