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 */
169 /* for use with IIO_VAL_INT_PLUS_MICRO */
170 #define MILLION 1000000
172 #define MESON_SAR_ADC_CHAN(_chan) { \
173 .type = IIO_VOLTAGE, \
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, \
185 * TODO: the hardware supports IIO_TEMP for channel 6 as well which is
186 * currently not supported by this driver.
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),
200 enum meson_sar_adc_avg_mode {
202 MEAN_AVERAGING = 0x1,
203 MEDIAN_AVERAGING = 0x2,
206 enum meson_sar_adc_num_samples {
213 enum meson_sar_adc_chan7_mux_sel {
215 CHAN7_MUX_VDD_DIV4 = 0x1,
216 CHAN7_MUX_VDD_DIV2 = 0x2,
217 CHAN7_MUX_VDD_MUL3_DIV4 = 0x3,
219 CHAN7_MUX_CH7_INPUT = 0x7,
222 struct meson_sar_adc_data {
223 unsigned int resolution;
227 struct meson_sar_adc_priv {
228 struct regmap *regmap;
229 struct regulator *vref;
230 const struct meson_sar_adc_data *data;
232 struct clk *core_clk;
233 struct clk *sana_clk;
234 struct clk *adc_sel_clk;
236 struct clk_gate clk_gate;
237 struct clk *adc_div_clk;
238 struct clk_divider clk_div;
239 struct completion done;
244 static const struct regmap_config meson_sar_adc_regmap_config = {
248 .max_register = MESON_SAR_ADC_REG13,
251 static unsigned int meson_sar_adc_get_fifo_count(struct iio_dev *indio_dev)
253 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
256 regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val);
258 return FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
261 static int meson_sar_adc_calib_val(struct iio_dev *indio_dev, int val)
263 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
266 /* use val_calib = scale * val_raw + offset calibration function */
267 tmp = div_s64((s64)val * priv->calibscale, MILLION) + priv->calibbias;
269 return clamp(tmp, 0, (1 << priv->data->resolution) - 1);
272 static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev)
274 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
275 int regval, timeout = 10000;
278 * NOTE: we need a small delay before reading the status, otherwise
279 * the sample engine may not have started internally (which would
280 * seem to us that sampling is already finished).
284 regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val);
285 } while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--);
293 static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
294 const struct iio_chan_spec *chan,
297 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
298 int regval, fifo_chan, fifo_val, count;
300 if(!wait_for_completion_timeout(&priv->done,
301 msecs_to_jiffies(MESON_SAR_ADC_TIMEOUT)))
304 count = meson_sar_adc_get_fifo_count(indio_dev);
306 dev_err(&indio_dev->dev,
307 "ADC FIFO has %d element(s) instead of one\n", count);
311 regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, ®val);
312 fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval);
313 if (fifo_chan != chan->channel) {
314 dev_err(&indio_dev->dev,
315 "ADC FIFO entry belongs to channel %d instead of %d\n",
316 fifo_chan, chan->channel);
320 fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK, regval);
321 fifo_val &= GENMASK(priv->data->resolution - 1, 0);
322 *val = meson_sar_adc_calib_val(indio_dev, fifo_val);
327 static void meson_sar_adc_set_averaging(struct iio_dev *indio_dev,
328 const struct iio_chan_spec *chan,
329 enum meson_sar_adc_avg_mode mode,
330 enum meson_sar_adc_num_samples samples)
332 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
333 int val, channel = chan->channel;
335 val = samples << MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(channel);
336 regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
337 MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(channel),
340 val = mode << MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(channel);
341 regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
342 MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(channel), val);
345 static void meson_sar_adc_enable_channel(struct iio_dev *indio_dev,
346 const struct iio_chan_spec *chan)
348 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
352 * the SAR ADC engine allows sampling multiple channels at the same
353 * time. to keep it simple we're only working with one *internal*
354 * channel, which starts counting at index 0 (which means: count = 1).
356 regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, 0);
357 regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
358 MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, regval);
360 /* map channel index 0 to the channel which we want to read */
361 regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0),
363 regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
364 MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0), regval);
366 regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
368 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
369 MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
372 regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
374 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
375 MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
378 if (chan->channel == 6)
379 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
380 MESON_SAR_ADC_DELTA_10_TEMP_SEL, 0);
383 static void meson_sar_adc_set_chan7_mux(struct iio_dev *indio_dev,
384 enum meson_sar_adc_chan7_mux_sel sel)
386 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
389 regval = FIELD_PREP(MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, sel);
390 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
391 MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, regval);
393 usleep_range(10, 20);
396 static void meson_sar_adc_start_sample_engine(struct iio_dev *indio_dev)
398 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
400 reinit_completion(&priv->done);
402 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
403 MESON_SAR_ADC_REG0_FIFO_IRQ_EN,
404 MESON_SAR_ADC_REG0_FIFO_IRQ_EN);
406 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
407 MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE,
408 MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE);
410 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
411 MESON_SAR_ADC_REG0_SAMPLING_START,
412 MESON_SAR_ADC_REG0_SAMPLING_START);
415 static void meson_sar_adc_stop_sample_engine(struct iio_dev *indio_dev)
417 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
419 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
420 MESON_SAR_ADC_REG0_FIFO_IRQ_EN, 0);
422 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
423 MESON_SAR_ADC_REG0_SAMPLING_STOP,
424 MESON_SAR_ADC_REG0_SAMPLING_STOP);
426 /* wait until all modules are stopped */
427 meson_sar_adc_wait_busy_clear(indio_dev);
429 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
430 MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE, 0);
433 static int meson_sar_adc_lock(struct iio_dev *indio_dev)
435 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
436 int val, timeout = 10000;
438 mutex_lock(&indio_dev->mlock);
440 /* prevent BL30 from using the SAR ADC while we are using it */
441 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
442 MESON_SAR_ADC_DELAY_KERNEL_BUSY,
443 MESON_SAR_ADC_DELAY_KERNEL_BUSY);
445 /* wait until BL30 releases it's lock (so we can use the SAR ADC) */
448 regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val);
449 } while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--);
457 static void meson_sar_adc_unlock(struct iio_dev *indio_dev)
459 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
461 /* allow BL30 to use the SAR ADC again */
462 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
463 MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0);
465 mutex_unlock(&indio_dev->mlock);
468 static void meson_sar_adc_clear_fifo(struct iio_dev *indio_dev)
470 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
473 for (count = 0; count < MESON_SAR_ADC_MAX_FIFO_SIZE; count++) {
474 if (!meson_sar_adc_get_fifo_count(indio_dev))
477 regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, 0);
481 static int meson_sar_adc_get_sample(struct iio_dev *indio_dev,
482 const struct iio_chan_spec *chan,
483 enum meson_sar_adc_avg_mode avg_mode,
484 enum meson_sar_adc_num_samples avg_samples,
489 ret = meson_sar_adc_lock(indio_dev);
493 /* clear the FIFO to make sure we're not reading old values */
494 meson_sar_adc_clear_fifo(indio_dev);
496 meson_sar_adc_set_averaging(indio_dev, chan, avg_mode, avg_samples);
498 meson_sar_adc_enable_channel(indio_dev, chan);
500 meson_sar_adc_start_sample_engine(indio_dev);
501 ret = meson_sar_adc_read_raw_sample(indio_dev, chan, val);
502 meson_sar_adc_stop_sample_engine(indio_dev);
504 meson_sar_adc_unlock(indio_dev);
507 dev_warn(indio_dev->dev.parent,
508 "failed to read sample for channel %d: %d\n",
516 static int meson_sar_adc_iio_info_read_raw(struct iio_dev *indio_dev,
517 const struct iio_chan_spec *chan,
518 int *val, int *val2, long mask)
520 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
524 case IIO_CHAN_INFO_RAW:
525 return meson_sar_adc_get_sample(indio_dev, chan, NO_AVERAGING,
529 case IIO_CHAN_INFO_AVERAGE_RAW:
530 return meson_sar_adc_get_sample(indio_dev, chan,
531 MEAN_AVERAGING, EIGHT_SAMPLES,
535 case IIO_CHAN_INFO_SCALE:
536 ret = regulator_get_voltage(priv->vref);
538 dev_err(indio_dev->dev.parent,
539 "failed to get vref voltage: %d\n", ret);
544 *val2 = priv->data->resolution;
545 return IIO_VAL_FRACTIONAL_LOG2;
547 case IIO_CHAN_INFO_CALIBBIAS:
548 *val = priv->calibbias;
551 case IIO_CHAN_INFO_CALIBSCALE:
552 *val = priv->calibscale / MILLION;
553 *val2 = priv->calibscale % MILLION;
554 return IIO_VAL_INT_PLUS_MICRO;
561 static int meson_sar_adc_clk_init(struct iio_dev *indio_dev,
564 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
565 struct clk_init_data init;
566 const char *clk_parents[1];
568 init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%s#adc_div",
569 of_node_full_name(indio_dev->dev.of_node));
571 init.ops = &clk_divider_ops;
572 clk_parents[0] = __clk_get_name(priv->clkin);
573 init.parent_names = clk_parents;
574 init.num_parents = 1;
576 priv->clk_div.reg = base + MESON_SAR_ADC_REG3;
577 priv->clk_div.shift = MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT;
578 priv->clk_div.width = MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH;
579 priv->clk_div.hw.init = &init;
580 priv->clk_div.flags = 0;
582 priv->adc_div_clk = devm_clk_register(&indio_dev->dev,
584 if (WARN_ON(IS_ERR(priv->adc_div_clk)))
585 return PTR_ERR(priv->adc_div_clk);
587 init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%s#adc_en",
588 of_node_full_name(indio_dev->dev.of_node));
589 init.flags = CLK_SET_RATE_PARENT;
590 init.ops = &clk_gate_ops;
591 clk_parents[0] = __clk_get_name(priv->adc_div_clk);
592 init.parent_names = clk_parents;
593 init.num_parents = 1;
595 priv->clk_gate.reg = base + MESON_SAR_ADC_REG3;
596 priv->clk_gate.bit_idx = fls(MESON_SAR_ADC_REG3_CLK_EN);
597 priv->clk_gate.hw.init = &init;
599 priv->adc_clk = devm_clk_register(&indio_dev->dev, &priv->clk_gate.hw);
600 if (WARN_ON(IS_ERR(priv->adc_clk)))
601 return PTR_ERR(priv->adc_clk);
606 static int meson_sar_adc_init(struct iio_dev *indio_dev)
608 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
612 * make sure we start at CH7 input since the other muxes are only used
613 * for internal calibration.
615 meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
618 * leave sampling delay and the input clocks as configured by BL30 to
619 * make sure BL30 gets the values it expects when reading the
620 * temperature sensor.
622 regmap_read(priv->regmap, MESON_SAR_ADC_REG3, ®val);
623 if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED)
626 meson_sar_adc_stop_sample_engine(indio_dev);
628 /* update the channel 6 MUX to select the temperature sensor */
629 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
630 MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL,
631 MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL);
633 /* disable all channels by default */
634 regmap_write(priv->regmap, MESON_SAR_ADC_CHAN_LIST, 0x0);
636 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
637 MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE, 0);
638 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
639 MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY,
640 MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY);
642 /* delay between two samples = (10+1) * 1uS */
643 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
644 MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
645 FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK,
647 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
648 MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
649 FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
652 /* delay between two samples = (10+1) * 1uS */
653 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
654 MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
655 FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
657 regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
658 MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
659 FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
662 ret = clk_set_parent(priv->adc_sel_clk, priv->clkin);
664 dev_err(indio_dev->dev.parent,
665 "failed to set adc parent to clkin\n");
669 ret = clk_set_rate(priv->adc_clk, 1200000);
671 dev_err(indio_dev->dev.parent,
672 "failed to set adc clock rate\n");
679 static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
681 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
685 ret = meson_sar_adc_lock(indio_dev);
689 ret = regulator_enable(priv->vref);
691 dev_err(indio_dev->dev.parent,
692 "failed to enable vref regulator\n");
696 ret = clk_prepare_enable(priv->core_clk);
698 dev_err(indio_dev->dev.parent, "failed to enable core clk\n");
702 ret = clk_prepare_enable(priv->sana_clk);
704 dev_err(indio_dev->dev.parent, "failed to enable sana clk\n");
708 regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1);
709 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
710 MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
711 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
712 MESON_SAR_ADC_REG11_BANDGAP_EN,
713 MESON_SAR_ADC_REG11_BANDGAP_EN);
714 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
715 MESON_SAR_ADC_REG3_ADC_EN,
716 MESON_SAR_ADC_REG3_ADC_EN);
720 ret = clk_prepare_enable(priv->adc_clk);
722 dev_err(indio_dev->dev.parent, "failed to enable adc clk\n");
726 meson_sar_adc_unlock(indio_dev);
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);
735 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 int meson_sar_adc_hw_disable(struct iio_dev *indio_dev)
748 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
751 ret = meson_sar_adc_lock(indio_dev);
755 clk_disable_unprepare(priv->adc_clk);
757 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
758 MESON_SAR_ADC_REG3_ADC_EN, 0);
759 regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
760 MESON_SAR_ADC_REG11_BANDGAP_EN, 0);
762 clk_disable_unprepare(priv->sana_clk);
763 clk_disable_unprepare(priv->core_clk);
765 regulator_disable(priv->vref);
767 meson_sar_adc_unlock(indio_dev);
772 static irqreturn_t meson_sar_adc_irq(int irq, void *data)
774 struct iio_dev *indio_dev = data;
775 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
776 unsigned int cnt, threshold;
779 regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val);
780 cnt = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
781 threshold = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
786 complete(&priv->done);
791 static int meson_sar_adc_calib(struct iio_dev *indio_dev)
793 struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
794 int ret, nominal0, nominal1, value0, value1;
796 /* use points 25% and 75% for calibration */
797 nominal0 = (1 << priv->data->resolution) / 4;
798 nominal1 = (1 << priv->data->resolution) * 3 / 4;
800 meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_DIV4);
801 usleep_range(10, 20);
802 ret = meson_sar_adc_get_sample(indio_dev,
803 &meson_sar_adc_iio_channels[7],
804 MEAN_AVERAGING, EIGHT_SAMPLES, &value0);
808 meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_MUL3_DIV4);
809 usleep_range(10, 20);
810 ret = meson_sar_adc_get_sample(indio_dev,
811 &meson_sar_adc_iio_channels[7],
812 MEAN_AVERAGING, EIGHT_SAMPLES, &value1);
816 if (value1 <= value0) {
821 priv->calibscale = div_s64((nominal1 - nominal0) * (s64)MILLION,
823 priv->calibbias = nominal0 - div_s64((s64)value0 * priv->calibscale,
827 meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
832 static const struct iio_info meson_sar_adc_iio_info = {
833 .read_raw = meson_sar_adc_iio_info_read_raw,
834 .driver_module = THIS_MODULE,
837 struct meson_sar_adc_data meson_sar_adc_gxbb_data = {
839 .name = "meson-gxbb-saradc",
842 struct meson_sar_adc_data meson_sar_adc_gxl_data = {
844 .name = "meson-gxl-saradc",
847 struct meson_sar_adc_data meson_sar_adc_gxm_data = {
849 .name = "meson-gxm-saradc",
852 static const struct of_device_id meson_sar_adc_of_match[] = {
854 .compatible = "amlogic,meson-gxbb-saradc",
855 .data = &meson_sar_adc_gxbb_data,
857 .compatible = "amlogic,meson-gxl-saradc",
858 .data = &meson_sar_adc_gxl_data,
860 .compatible = "amlogic,meson-gxm-saradc",
861 .data = &meson_sar_adc_gxm_data,
865 MODULE_DEVICE_TABLE(of, meson_sar_adc_of_match);
867 static int meson_sar_adc_probe(struct platform_device *pdev)
869 struct meson_sar_adc_priv *priv;
870 struct iio_dev *indio_dev;
871 struct resource *res;
873 const struct of_device_id *match;
876 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
878 dev_err(&pdev->dev, "failed allocating iio device\n");
882 priv = iio_priv(indio_dev);
883 init_completion(&priv->done);
885 match = of_match_device(meson_sar_adc_of_match, &pdev->dev);
886 priv->data = match->data;
888 indio_dev->name = priv->data->name;
889 indio_dev->dev.parent = &pdev->dev;
890 indio_dev->dev.of_node = pdev->dev.of_node;
891 indio_dev->modes = INDIO_DIRECT_MODE;
892 indio_dev->info = &meson_sar_adc_iio_info;
894 indio_dev->channels = meson_sar_adc_iio_channels;
895 indio_dev->num_channels = ARRAY_SIZE(meson_sar_adc_iio_channels);
897 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
898 base = devm_ioremap_resource(&pdev->dev, res);
900 return PTR_ERR(base);
902 irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
906 ret = devm_request_irq(&pdev->dev, irq, meson_sar_adc_irq, IRQF_SHARED,
907 dev_name(&pdev->dev), indio_dev);
911 priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
912 &meson_sar_adc_regmap_config);
913 if (IS_ERR(priv->regmap))
914 return PTR_ERR(priv->regmap);
916 priv->clkin = devm_clk_get(&pdev->dev, "clkin");
917 if (IS_ERR(priv->clkin)) {
918 dev_err(&pdev->dev, "failed to get clkin\n");
919 return PTR_ERR(priv->clkin);
922 priv->core_clk = devm_clk_get(&pdev->dev, "core");
923 if (IS_ERR(priv->core_clk)) {
924 dev_err(&pdev->dev, "failed to get core clk\n");
925 return PTR_ERR(priv->core_clk);
928 priv->sana_clk = devm_clk_get(&pdev->dev, "sana");
929 if (IS_ERR(priv->sana_clk)) {
930 if (PTR_ERR(priv->sana_clk) == -ENOENT) {
931 priv->sana_clk = NULL;
933 dev_err(&pdev->dev, "failed to get sana clk\n");
934 return PTR_ERR(priv->sana_clk);
938 priv->adc_clk = devm_clk_get(&pdev->dev, "adc_clk");
939 if (IS_ERR(priv->adc_clk)) {
940 if (PTR_ERR(priv->adc_clk) == -ENOENT) {
941 priv->adc_clk = NULL;
943 dev_err(&pdev->dev, "failed to get adc clk\n");
944 return PTR_ERR(priv->adc_clk);
948 priv->adc_sel_clk = devm_clk_get(&pdev->dev, "adc_sel");
949 if (IS_ERR(priv->adc_sel_clk)) {
950 if (PTR_ERR(priv->adc_sel_clk) == -ENOENT) {
951 priv->adc_sel_clk = NULL;
953 dev_err(&pdev->dev, "failed to get adc_sel clk\n");
954 return PTR_ERR(priv->adc_sel_clk);
958 /* on pre-GXBB SoCs the SAR ADC itself provides the ADC clock: */
959 if (!priv->adc_clk) {
960 ret = meson_sar_adc_clk_init(indio_dev, base);
965 priv->vref = devm_regulator_get(&pdev->dev, "vref");
966 if (IS_ERR(priv->vref)) {
967 dev_err(&pdev->dev, "failed to get vref regulator\n");
968 return PTR_ERR(priv->vref);
971 priv->calibscale = MILLION;
973 ret = meson_sar_adc_init(indio_dev);
977 ret = meson_sar_adc_hw_enable(indio_dev);
981 ret = meson_sar_adc_calib(indio_dev);
983 dev_warn(&pdev->dev, "calibration failed\n");
985 platform_set_drvdata(pdev, indio_dev);
987 ret = iio_device_register(indio_dev);
994 meson_sar_adc_hw_disable(indio_dev);
999 static int meson_sar_adc_remove(struct platform_device *pdev)
1001 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1003 iio_device_unregister(indio_dev);
1005 return meson_sar_adc_hw_disable(indio_dev);
1008 static int __maybe_unused meson_sar_adc_suspend(struct device *dev)
1010 struct iio_dev *indio_dev = dev_get_drvdata(dev);
1012 return meson_sar_adc_hw_disable(indio_dev);
1015 static int __maybe_unused meson_sar_adc_resume(struct device *dev)
1017 struct iio_dev *indio_dev = dev_get_drvdata(dev);
1019 return meson_sar_adc_hw_enable(indio_dev);
1022 static SIMPLE_DEV_PM_OPS(meson_sar_adc_pm_ops,
1023 meson_sar_adc_suspend, meson_sar_adc_resume);
1025 static struct platform_driver meson_sar_adc_driver = {
1026 .probe = meson_sar_adc_probe,
1027 .remove = meson_sar_adc_remove,
1029 .name = "meson-saradc",
1030 .of_match_table = meson_sar_adc_of_match,
1031 .pm = &meson_sar_adc_pm_ops,
1035 module_platform_driver(meson_sar_adc_driver);
1037 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
1038 MODULE_DESCRIPTION("Amlogic Meson SAR ADC driver");
1039 MODULE_LICENSE("GPL v2");