2 * Amlogic Meson Successive Approximation Register (SAR) A/D Converter
4 * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
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.
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/>.
14 #include <linux/bitfield.h>
15 #include <linux/clk.h>
16 #include <linux/clk-provider.h>
17 #include <linux/delay.h>
19 #include <linux/iio/iio.h>
20 #include <linux/module.h>
21 #include <linux/interrupt.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>
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)
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))
56 #define MESON_SAR_ADC_AVG_CNTL 0x08
57 #define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(_chan) \
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) \
63 #define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(_chan) \
64 (GENMASK(1, 0) << ((_chan) * 2))
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)
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)
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)
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)
98 #define MESON_SAR_ADC_AUX_SW 0x1c
99 #define MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_MASK(_chan) \
100 (GENMASK(10, 8) << (((_chan) - 2) * 2))
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)
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)
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)
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)
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
161 #define MESON_SAR_ADC_REG11 0x2c
162 #define MESON_SAR_ADC_REG11_BANDGAP_EN BIT(13)
164 #define MESON_SAR_ADC_REG13 0x34
165 #define MESON_SAR_ADC_REG13_12BIT_CALIBRATION_MASK GENMASK(13, 8)
167 #define MESON_SAR_ADC_MAX_FIFO_SIZE 32
168 #define MESON_SAR_ADC_TIMEOUT 100 /* ms */
170 #define MESON_SAR_ADC_CHAN(_chan) { \
171 .type = IIO_VOLTAGE, \
174 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
175 BIT(IIO_CHAN_INFO_AVERAGE_RAW), \
176 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
177 .datasheet_name = "SAR_ADC_CH"#_chan, \
181 * TODO: the hardware supports IIO_TEMP for channel 6 as well which is
182 * currently not supported by this driver.
184 static const struct iio_chan_spec meson_sar_adc_iio_channels[] = {
185 MESON_SAR_ADC_CHAN(0),
186 MESON_SAR_ADC_CHAN(1),
187 MESON_SAR_ADC_CHAN(2),
188 MESON_SAR_ADC_CHAN(3),
189 MESON_SAR_ADC_CHAN(4),
190 MESON_SAR_ADC_CHAN(5),
191 MESON_SAR_ADC_CHAN(6),
192 MESON_SAR_ADC_CHAN(7),
193 IIO_CHAN_SOFT_TIMESTAMP(8),
196 enum meson_sar_adc_avg_mode {
198 MEAN_AVERAGING = 0x1,
199 MEDIAN_AVERAGING = 0x2,
202 enum meson_sar_adc_num_samples {
209 enum meson_sar_adc_chan7_mux_sel {
211 CHAN7_MUX_VDD_DIV4 = 0x1,
212 CHAN7_MUX_VDD_DIV2 = 0x2,
213 CHAN7_MUX_VDD_MUL3_DIV4 = 0x3,
215 CHAN7_MUX_CH7_INPUT = 0x7,
218 struct meson_sar_adc_data {
219 unsigned int resolution;
223 struct meson_sar_adc_priv {
224 struct regmap *regmap;
225 struct regulator *vref;
226 const struct meson_sar_adc_data *data;
228 struct clk *core_clk;
229 struct clk *sana_clk;
230 struct clk *adc_sel_clk;
232 struct clk_gate clk_gate;
233 struct clk *adc_div_clk;
234 struct clk_divider clk_div;
235 struct completion done;
238 static const struct regmap_config meson_sar_adc_regmap_config = {
242 .max_register = MESON_SAR_ADC_REG13,
245 static unsigned int meson_sar_adc_get_fifo_count(struct iio_dev *indio_dev)
247 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
250 regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val);
252 return FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
255 static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev)
257 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
258 int regval, timeout = 10000;
261 * NOTE: we need a small delay before reading the status, otherwise
262 * the sample engine may not have started internally (which would
263 * seem to us that sampling is already finished).
267 regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val);
268 } while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--);
276 static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
277 const struct iio_chan_spec *chan,
280 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
281 int regval, fifo_chan, fifo_val, count;
283 if(!wait_for_completion_timeout(&priv->done,
284 msecs_to_jiffies(MESON_SAR_ADC_TIMEOUT)))
287 count = meson_sar_adc_get_fifo_count(indio_dev);
289 dev_err(&indio_dev->dev,
290 "ADC FIFO has %d element(s) instead of one\n", count);
294 regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, ®val);
295 fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval);
296 if (fifo_chan != chan->channel) {
297 dev_err(&indio_dev->dev,
298 "ADC FIFO entry belongs to channel %d instead of %d\n",
299 fifo_chan, chan->channel);
303 fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK, regval);
304 fifo_val &= GENMASK(priv->data->resolution - 1, 0);
310 static void meson_sar_adc_set_averaging(struct iio_dev *indio_dev,
311 const struct iio_chan_spec *chan,
312 enum meson_sar_adc_avg_mode mode,
313 enum meson_sar_adc_num_samples samples)
315 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
316 int val, channel = chan->channel;
318 val = samples << MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(channel);
319 regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
320 MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(channel),
323 val = mode << MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(channel);
324 regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
325 MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(channel), val);
328 static void meson_sar_adc_enable_channel(struct iio_dev *indio_dev,
329 const struct iio_chan_spec *chan)
331 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
335 * the SAR ADC engine allows sampling multiple channels at the same
336 * time. to keep it simple we're only working with one *internal*
337 * channel, which starts counting at index 0 (which means: count = 1).
339 regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, 0);
340 regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
341 MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, regval);
343 /* map channel index 0 to the channel which we want to read */
344 regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0),
346 regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
347 MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0), regval);
349 regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
351 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
352 MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
355 regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
357 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
358 MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
361 if (chan->channel == 6)
362 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
363 MESON_SAR_ADC_DELTA_10_TEMP_SEL, 0);
366 static void meson_sar_adc_set_chan7_mux(struct iio_dev *indio_dev,
367 enum meson_sar_adc_chan7_mux_sel sel)
369 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
372 regval = FIELD_PREP(MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, sel);
373 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
374 MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, regval);
376 usleep_range(10, 20);
379 static void meson_sar_adc_start_sample_engine(struct iio_dev *indio_dev)
381 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
383 reinit_completion(&priv->done);
385 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
386 MESON_SAR_ADC_REG0_FIFO_IRQ_EN,
387 MESON_SAR_ADC_REG0_FIFO_IRQ_EN);
389 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
390 MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE,
391 MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE);
393 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
394 MESON_SAR_ADC_REG0_SAMPLING_START,
395 MESON_SAR_ADC_REG0_SAMPLING_START);
398 static void meson_sar_adc_stop_sample_engine(struct iio_dev *indio_dev)
400 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
402 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
403 MESON_SAR_ADC_REG0_FIFO_IRQ_EN, 0);
405 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
406 MESON_SAR_ADC_REG0_SAMPLING_STOP,
407 MESON_SAR_ADC_REG0_SAMPLING_STOP);
409 /* wait until all modules are stopped */
410 meson_sar_adc_wait_busy_clear(indio_dev);
412 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
413 MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE, 0);
416 static int meson_sar_adc_lock(struct iio_dev *indio_dev)
418 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
419 int val, timeout = 10000;
421 mutex_lock(&indio_dev->mlock);
423 /* prevent BL30 from using the SAR ADC while we are using it */
424 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
425 MESON_SAR_ADC_DELAY_KERNEL_BUSY,
426 MESON_SAR_ADC_DELAY_KERNEL_BUSY);
428 /* wait until BL30 releases it's lock (so we can use the SAR ADC) */
431 regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val);
432 } while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--);
440 static void meson_sar_adc_unlock(struct iio_dev *indio_dev)
442 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
444 /* allow BL30 to use the SAR ADC again */
445 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
446 MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0);
448 mutex_unlock(&indio_dev->mlock);
451 static void meson_sar_adc_clear_fifo(struct iio_dev *indio_dev)
453 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
456 for (count = 0; count < MESON_SAR_ADC_MAX_FIFO_SIZE; count++) {
457 if (!meson_sar_adc_get_fifo_count(indio_dev))
460 regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, 0);
464 static int meson_sar_adc_get_sample(struct iio_dev *indio_dev,
465 const struct iio_chan_spec *chan,
466 enum meson_sar_adc_avg_mode avg_mode,
467 enum meson_sar_adc_num_samples avg_samples,
472 ret = meson_sar_adc_lock(indio_dev);
476 /* clear the FIFO to make sure we're not reading old values */
477 meson_sar_adc_clear_fifo(indio_dev);
479 meson_sar_adc_set_averaging(indio_dev, chan, avg_mode, avg_samples);
481 meson_sar_adc_enable_channel(indio_dev, chan);
483 meson_sar_adc_start_sample_engine(indio_dev);
484 ret = meson_sar_adc_read_raw_sample(indio_dev, chan, val);
485 meson_sar_adc_stop_sample_engine(indio_dev);
487 meson_sar_adc_unlock(indio_dev);
490 dev_warn(indio_dev->dev.parent,
491 "failed to read sample for channel %d: %d\n",
499 static int meson_sar_adc_iio_info_read_raw(struct iio_dev *indio_dev,
500 const struct iio_chan_spec *chan,
501 int *val, int *val2, long mask)
503 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
507 case IIO_CHAN_INFO_RAW:
508 return meson_sar_adc_get_sample(indio_dev, chan, NO_AVERAGING,
512 case IIO_CHAN_INFO_AVERAGE_RAW:
513 return meson_sar_adc_get_sample(indio_dev, chan,
514 MEAN_AVERAGING, EIGHT_SAMPLES,
518 case IIO_CHAN_INFO_SCALE:
519 ret = regulator_get_voltage(priv->vref);
521 dev_err(indio_dev->dev.parent,
522 "failed to get vref voltage: %d\n", ret);
527 *val2 = priv->data->resolution;
528 return IIO_VAL_FRACTIONAL_LOG2;
535 static int meson_sar_adc_clk_init(struct iio_dev *indio_dev,
538 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
539 struct clk_init_data init;
540 const char *clk_parents[1];
542 init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%s#adc_div",
543 of_node_full_name(indio_dev->dev.of_node));
545 init.ops = &clk_divider_ops;
546 clk_parents[0] = __clk_get_name(priv->clkin);
547 init.parent_names = clk_parents;
548 init.num_parents = 1;
550 priv->clk_div.reg = base + MESON_SAR_ADC_REG3;
551 priv->clk_div.shift = MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT;
552 priv->clk_div.width = MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH;
553 priv->clk_div.hw.init = &init;
554 priv->clk_div.flags = 0;
556 priv->adc_div_clk = devm_clk_register(&indio_dev->dev,
558 if (WARN_ON(IS_ERR(priv->adc_div_clk)))
559 return PTR_ERR(priv->adc_div_clk);
561 init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%s#adc_en",
562 of_node_full_name(indio_dev->dev.of_node));
563 init.flags = CLK_SET_RATE_PARENT;
564 init.ops = &clk_gate_ops;
565 clk_parents[0] = __clk_get_name(priv->adc_div_clk);
566 init.parent_names = clk_parents;
567 init.num_parents = 1;
569 priv->clk_gate.reg = base + MESON_SAR_ADC_REG3;
570 priv->clk_gate.bit_idx = fls(MESON_SAR_ADC_REG3_CLK_EN);
571 priv->clk_gate.hw.init = &init;
573 priv->adc_clk = devm_clk_register(&indio_dev->dev, &priv->clk_gate.hw);
574 if (WARN_ON(IS_ERR(priv->adc_clk)))
575 return PTR_ERR(priv->adc_clk);
580 static int meson_sar_adc_init(struct iio_dev *indio_dev)
582 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
586 * make sure we start at CH7 input since the other muxes are only used
587 * for internal calibration.
589 meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
592 * leave sampling delay and the input clocks as configured by BL30 to
593 * make sure BL30 gets the values it expects when reading the
594 * temperature sensor.
596 regmap_read(priv->regmap, MESON_SAR_ADC_REG3, ®val);
597 if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED)
600 meson_sar_adc_stop_sample_engine(indio_dev);
602 /* update the channel 6 MUX to select the temperature sensor */
603 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
604 MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL,
605 MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL);
607 /* disable all channels by default */
608 regmap_write(priv->regmap, MESON_SAR_ADC_CHAN_LIST, 0x0);
610 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
611 MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE, 0);
612 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
613 MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY,
614 MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY);
616 /* delay between two samples = (10+1) * 1uS */
617 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
618 MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
619 FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK,
621 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
622 MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
623 FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
626 /* delay between two samples = (10+1) * 1uS */
627 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
628 MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
629 FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
631 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
632 MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
633 FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
636 ret = clk_set_parent(priv->adc_sel_clk, priv->clkin);
638 dev_err(indio_dev->dev.parent,
639 "failed to set adc parent to clkin\n");
643 ret = clk_set_rate(priv->adc_clk, 1200000);
645 dev_err(indio_dev->dev.parent,
646 "failed to set adc clock rate\n");
653 static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
655 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
659 ret = meson_sar_adc_lock(indio_dev);
663 ret = regulator_enable(priv->vref);
665 dev_err(indio_dev->dev.parent,
666 "failed to enable vref regulator\n");
670 ret = clk_prepare_enable(priv->core_clk);
672 dev_err(indio_dev->dev.parent, "failed to enable core clk\n");
676 ret = clk_prepare_enable(priv->sana_clk);
678 dev_err(indio_dev->dev.parent, "failed to enable sana clk\n");
682 regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1);
683 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
684 MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
685 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
686 MESON_SAR_ADC_REG11_BANDGAP_EN,
687 MESON_SAR_ADC_REG11_BANDGAP_EN);
688 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
689 MESON_SAR_ADC_REG3_ADC_EN,
690 MESON_SAR_ADC_REG3_ADC_EN);
694 ret = clk_prepare_enable(priv->adc_clk);
696 dev_err(indio_dev->dev.parent, "failed to enable adc clk\n");
700 meson_sar_adc_unlock(indio_dev);
705 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
706 MESON_SAR_ADC_REG3_ADC_EN, 0);
707 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
708 MESON_SAR_ADC_REG11_BANDGAP_EN, 0);
709 clk_disable_unprepare(priv->sana_clk);
711 clk_disable_unprepare(priv->core_clk);
713 regulator_disable(priv->vref);
715 meson_sar_adc_unlock(indio_dev);
720 static int meson_sar_adc_hw_disable(struct iio_dev *indio_dev)
722 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
725 ret = meson_sar_adc_lock(indio_dev);
729 clk_disable_unprepare(priv->adc_clk);
731 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
732 MESON_SAR_ADC_REG3_ADC_EN, 0);
733 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
734 MESON_SAR_ADC_REG11_BANDGAP_EN, 0);
736 clk_disable_unprepare(priv->sana_clk);
737 clk_disable_unprepare(priv->core_clk);
739 regulator_disable(priv->vref);
741 meson_sar_adc_unlock(indio_dev);
746 static irqreturn_t meson_sar_adc_irq(int irq, void *data)
748 struct iio_dev *indio_dev = data;
749 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
750 unsigned int cnt, threshold;
753 regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val);
754 cnt = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
755 threshold = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
760 complete(&priv->done);
765 static const struct iio_info meson_sar_adc_iio_info = {
766 .read_raw = meson_sar_adc_iio_info_read_raw,
767 .driver_module = THIS_MODULE,
770 struct meson_sar_adc_data meson_sar_adc_gxbb_data = {
772 .name = "meson-gxbb-saradc",
775 struct meson_sar_adc_data meson_sar_adc_gxl_data = {
777 .name = "meson-gxl-saradc",
780 struct meson_sar_adc_data meson_sar_adc_gxm_data = {
782 .name = "meson-gxm-saradc",
785 static const struct of_device_id meson_sar_adc_of_match[] = {
787 .compatible = "amlogic,meson-gxbb-saradc",
788 .data = &meson_sar_adc_gxbb_data,
790 .compatible = "amlogic,meson-gxl-saradc",
791 .data = &meson_sar_adc_gxl_data,
793 .compatible = "amlogic,meson-gxm-saradc",
794 .data = &meson_sar_adc_gxm_data,
798 MODULE_DEVICE_TABLE(of, meson_sar_adc_of_match);
800 static int meson_sar_adc_probe(struct platform_device *pdev)
802 struct meson_sar_adc_priv *priv;
803 struct iio_dev *indio_dev;
804 struct resource *res;
806 const struct of_device_id *match;
809 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
811 dev_err(&pdev->dev, "failed allocating iio device\n");
815 priv = iio_priv(indio_dev);
816 init_completion(&priv->done);
818 match = of_match_device(meson_sar_adc_of_match, &pdev->dev);
819 priv->data = match->data;
821 indio_dev->name = priv->data->name;
822 indio_dev->dev.parent = &pdev->dev;
823 indio_dev->dev.of_node = pdev->dev.of_node;
824 indio_dev->modes = INDIO_DIRECT_MODE;
825 indio_dev->info = &meson_sar_adc_iio_info;
827 indio_dev->channels = meson_sar_adc_iio_channels;
828 indio_dev->num_channels = ARRAY_SIZE(meson_sar_adc_iio_channels);
830 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
831 base = devm_ioremap_resource(&pdev->dev, res);
833 return PTR_ERR(base);
835 irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
839 ret = devm_request_irq(&pdev->dev, irq, meson_sar_adc_irq, IRQF_SHARED,
840 dev_name(&pdev->dev), indio_dev);
844 priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
845 &meson_sar_adc_regmap_config);
846 if (IS_ERR(priv->regmap))
847 return PTR_ERR(priv->regmap);
849 priv->clkin = devm_clk_get(&pdev->dev, "clkin");
850 if (IS_ERR(priv->clkin)) {
851 dev_err(&pdev->dev, "failed to get clkin\n");
852 return PTR_ERR(priv->clkin);
855 priv->core_clk = devm_clk_get(&pdev->dev, "core");
856 if (IS_ERR(priv->core_clk)) {
857 dev_err(&pdev->dev, "failed to get core clk\n");
858 return PTR_ERR(priv->core_clk);
861 priv->sana_clk = devm_clk_get(&pdev->dev, "sana");
862 if (IS_ERR(priv->sana_clk)) {
863 if (PTR_ERR(priv->sana_clk) == -ENOENT) {
864 priv->sana_clk = NULL;
866 dev_err(&pdev->dev, "failed to get sana clk\n");
867 return PTR_ERR(priv->sana_clk);
871 priv->adc_clk = devm_clk_get(&pdev->dev, "adc_clk");
872 if (IS_ERR(priv->adc_clk)) {
873 if (PTR_ERR(priv->adc_clk) == -ENOENT) {
874 priv->adc_clk = NULL;
876 dev_err(&pdev->dev, "failed to get adc clk\n");
877 return PTR_ERR(priv->adc_clk);
881 priv->adc_sel_clk = devm_clk_get(&pdev->dev, "adc_sel");
882 if (IS_ERR(priv->adc_sel_clk)) {
883 if (PTR_ERR(priv->adc_sel_clk) == -ENOENT) {
884 priv->adc_sel_clk = NULL;
886 dev_err(&pdev->dev, "failed to get adc_sel clk\n");
887 return PTR_ERR(priv->adc_sel_clk);
891 /* on pre-GXBB SoCs the SAR ADC itself provides the ADC clock: */
892 if (!priv->adc_clk) {
893 ret = meson_sar_adc_clk_init(indio_dev, base);
898 priv->vref = devm_regulator_get(&pdev->dev, "vref");
899 if (IS_ERR(priv->vref)) {
900 dev_err(&pdev->dev, "failed to get vref regulator\n");
901 return PTR_ERR(priv->vref);
904 ret = meson_sar_adc_init(indio_dev);
908 ret = meson_sar_adc_hw_enable(indio_dev);
912 platform_set_drvdata(pdev, indio_dev);
914 ret = iio_device_register(indio_dev);
921 meson_sar_adc_hw_disable(indio_dev);
926 static int meson_sar_adc_remove(struct platform_device *pdev)
928 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
930 iio_device_unregister(indio_dev);
932 return meson_sar_adc_hw_disable(indio_dev);
935 static int __maybe_unused meson_sar_adc_suspend(struct device *dev)
937 struct iio_dev *indio_dev = dev_get_drvdata(dev);
939 return meson_sar_adc_hw_disable(indio_dev);
942 static int __maybe_unused meson_sar_adc_resume(struct device *dev)
944 struct iio_dev *indio_dev = dev_get_drvdata(dev);
946 return meson_sar_adc_hw_enable(indio_dev);
949 static SIMPLE_DEV_PM_OPS(meson_sar_adc_pm_ops,
950 meson_sar_adc_suspend, meson_sar_adc_resume);
952 static struct platform_driver meson_sar_adc_driver = {
953 .probe = meson_sar_adc_probe,
954 .remove = meson_sar_adc_remove,
956 .name = "meson-saradc",
957 .of_match_table = meson_sar_adc_of_match,
958 .pm = &meson_sar_adc_pm_ops,
962 module_platform_driver(meson_sar_adc_driver);
964 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
965 MODULE_DESCRIPTION("Amlogic Meson SAR ADC driver");
966 MODULE_LICENSE("GPL v2");