/* * Amlogic Meson Successive Approximation Register (SAR) A/D Converter * * Copyright (C) 2017 Martin Blumenstingl * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define MESON_SAR_ADC_REG0 0x00 #define MESON_SAR_ADC_REG0_PANEL_DETECT BIT(31) #define MESON_SAR_ADC_REG0_BUSY_MASK GENMASK(30, 28) #define MESON_SAR_ADC_REG0_DELTA_BUSY BIT(30) #define MESON_SAR_ADC_REG0_AVG_BUSY BIT(29) #define MESON_SAR_ADC_REG0_SAMPLE_BUSY BIT(28) #define MESON_SAR_ADC_REG0_FIFO_FULL BIT(27) #define MESON_SAR_ADC_REG0_FIFO_EMPTY BIT(26) #define MESON_SAR_ADC_REG0_FIFO_COUNT_MASK GENMASK(25, 21) #define MESON_SAR_ADC_REG0_ADC_BIAS_CTRL_MASK GENMASK(20, 19) #define MESON_SAR_ADC_REG0_CURR_CHAN_ID_MASK GENMASK(18, 16) #define MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL BIT(15) #define MESON_SAR_ADC_REG0_SAMPLING_STOP BIT(14) #define MESON_SAR_ADC_REG0_CHAN_DELTA_EN_MASK GENMASK(13, 12) #define MESON_SAR_ADC_REG0_DETECT_IRQ_POL BIT(10) #define MESON_SAR_ADC_REG0_DETECT_IRQ_EN BIT(9) #define MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK GENMASK(8, 4) #define MESON_SAR_ADC_REG0_FIFO_IRQ_EN BIT(3) #define MESON_SAR_ADC_REG0_SAMPLING_START BIT(2) #define MESON_SAR_ADC_REG0_CONTINUOUS_EN BIT(1) #define MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE BIT(0) #define MESON_SAR_ADC_CHAN_LIST 0x04 #define MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK GENMASK(26, 24) #define MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(_chan) \ (GENMASK(2, 0) << ((_chan) * 3)) #define MESON_SAR_ADC_AVG_CNTL 0x08 #define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(_chan) \ (16 + ((_chan) * 2)) #define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(_chan) \ (GENMASK(17, 16) << ((_chan) * 2)) #define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(_chan) \ (0 + ((_chan) * 2)) #define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(_chan) \ (GENMASK(1, 0) << ((_chan) * 2)) #define MESON_SAR_ADC_REG3 0x0c #define MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY BIT(31) #define MESON_SAR_ADC_REG3_CLK_EN BIT(30) #define MESON_SAR_ADC_REG3_BL30_INITIALIZED BIT(28) #define MESON_SAR_ADC_REG3_CTRL_CONT_RING_COUNTER_EN BIT(27) #define MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE BIT(26) #define MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK GENMASK(25, 23) #define MESON_SAR_ADC_REG3_DETECT_EN BIT(22) #define MESON_SAR_ADC_REG3_ADC_EN BIT(21) #define MESON_SAR_ADC_REG3_PANEL_DETECT_COUNT_MASK GENMASK(20, 18) #define MESON_SAR_ADC_REG3_PANEL_DETECT_FILTER_TB_MASK GENMASK(17, 16) #define MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT 10 #define MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH 5 #define MESON_SAR_ADC_REG3_BLOCK_DLY_SEL_MASK GENMASK(9, 8) #define MESON_SAR_ADC_REG3_BLOCK_DLY_MASK GENMASK(7, 0) #define MESON_SAR_ADC_DELAY 0x10 #define MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK GENMASK(25, 24) #define MESON_SAR_ADC_DELAY_BL30_BUSY BIT(15) #define MESON_SAR_ADC_DELAY_KERNEL_BUSY BIT(14) #define MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK GENMASK(23, 16) #define MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK GENMASK(9, 8) #define MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK GENMASK(7, 0) #define MESON_SAR_ADC_LAST_RD 0x14 #define MESON_SAR_ADC_LAST_RD_LAST_CHANNEL1_MASK GENMASK(23, 16) #define MESON_SAR_ADC_LAST_RD_LAST_CHANNEL0_MASK GENMASK(9, 0) #define MESON_SAR_ADC_FIFO_RD 0x18 #define MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK GENMASK(14, 12) #define MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK GENMASK(11, 0) #define MESON_SAR_ADC_AUX_SW 0x1c #define MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_MASK(_chan) \ (GENMASK(10, 8) << (((_chan) - 2) * 2)) #define MESON_SAR_ADC_AUX_SW_VREF_P_MUX BIT(6) #define MESON_SAR_ADC_AUX_SW_VREF_N_MUX BIT(5) #define MESON_SAR_ADC_AUX_SW_MODE_SEL BIT(4) #define MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW BIT(3) #define MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW BIT(2) #define MESON_SAR_ADC_AUX_SW_YM_DRIVE_SW BIT(1) #define MESON_SAR_ADC_AUX_SW_XM_DRIVE_SW BIT(0) #define MESON_SAR_ADC_CHAN_10_SW 0x20 #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK GENMASK(25, 23) #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_VREF_P_MUX BIT(22) #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_VREF_N_MUX BIT(21) #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_MODE_SEL BIT(20) #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_YP_DRIVE_SW BIT(19) #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_XP_DRIVE_SW BIT(18) #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_YM_DRIVE_SW BIT(17) #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_XM_DRIVE_SW BIT(16) #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK GENMASK(9, 7) #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_VREF_P_MUX BIT(6) #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_VREF_N_MUX BIT(5) #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_MODE_SEL BIT(4) #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_YP_DRIVE_SW BIT(3) #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_XP_DRIVE_SW BIT(2) #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_YM_DRIVE_SW BIT(1) #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_XM_DRIVE_SW BIT(0) #define MESON_SAR_ADC_DETECT_IDLE_SW 0x24 #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_SW_EN BIT(26) #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK GENMASK(25, 23) #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_VREF_P_MUX BIT(22) #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_VREF_N_MUX BIT(21) #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MODE_SEL BIT(20) #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_YP_DRIVE_SW BIT(19) #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_XP_DRIVE_SW BIT(18) #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_YM_DRIVE_SW BIT(17) #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_XM_DRIVE_SW BIT(16) #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK GENMASK(9, 7) #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_VREF_P_MUX BIT(6) #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_VREF_N_MUX BIT(5) #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MODE_SEL BIT(4) #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_YP_DRIVE_SW BIT(3) #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_XP_DRIVE_SW BIT(2) #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_YM_DRIVE_SW BIT(1) #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_XM_DRIVE_SW BIT(0) #define MESON_SAR_ADC_DELTA_10 0x28 #define MESON_SAR_ADC_DELTA_10_TEMP_SEL BIT(27) #define MESON_SAR_ADC_DELTA_10_TS_REVE1 BIT(26) #define MESON_SAR_ADC_DELTA_10_CHAN1_DELTA_VALUE_MASK GENMASK(25, 16) #define MESON_SAR_ADC_DELTA_10_TS_REVE0 BIT(15) #define MESON_SAR_ADC_DELTA_10_TS_C_SHIFT 11 #define MESON_SAR_ADC_DELTA_10_TS_C_MASK GENMASK(14, 11) #define MESON_SAR_ADC_DELTA_10_TS_VBG_EN BIT(10) #define MESON_SAR_ADC_DELTA_10_CHAN0_DELTA_VALUE_MASK GENMASK(9, 0) /* * NOTE: registers from here are undocumented (the vendor Linux kernel driver * and u-boot source served as reference). These only seem to be relevant on * GXBB and newer. */ #define MESON_SAR_ADC_REG11 0x2c #define MESON_SAR_ADC_REG11_BANDGAP_EN BIT(13) #define MESON_SAR_ADC_REG13 0x34 #define MESON_SAR_ADC_REG13_12BIT_CALIBRATION_MASK GENMASK(13, 8) #define MESON_SAR_ADC_MAX_FIFO_SIZE 32 #define MESON_SAR_ADC_TIMEOUT 100 /* ms */ /* for use with IIO_VAL_INT_PLUS_MICRO */ #define MILLION 1000000 #define MESON_SAR_ADC_CHAN(_chan) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = _chan, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ BIT(IIO_CHAN_INFO_AVERAGE_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ BIT(IIO_CHAN_INFO_CALIBBIAS) | \ BIT(IIO_CHAN_INFO_CALIBSCALE), \ .datasheet_name = "SAR_ADC_CH"#_chan, \ } /* * TODO: the hardware supports IIO_TEMP for channel 6 as well which is * currently not supported by this driver. */ static const struct iio_chan_spec meson_sar_adc_iio_channels[] = { MESON_SAR_ADC_CHAN(0), MESON_SAR_ADC_CHAN(1), MESON_SAR_ADC_CHAN(2), MESON_SAR_ADC_CHAN(3), MESON_SAR_ADC_CHAN(4), MESON_SAR_ADC_CHAN(5), MESON_SAR_ADC_CHAN(6), MESON_SAR_ADC_CHAN(7), IIO_CHAN_SOFT_TIMESTAMP(8), }; enum meson_sar_adc_avg_mode { NO_AVERAGING = 0x0, MEAN_AVERAGING = 0x1, MEDIAN_AVERAGING = 0x2, }; enum meson_sar_adc_num_samples { ONE_SAMPLE = 0x0, TWO_SAMPLES = 0x1, FOUR_SAMPLES = 0x2, EIGHT_SAMPLES = 0x3, }; enum meson_sar_adc_chan7_mux_sel { CHAN7_MUX_VSS = 0x0, CHAN7_MUX_VDD_DIV4 = 0x1, CHAN7_MUX_VDD_DIV2 = 0x2, CHAN7_MUX_VDD_MUL3_DIV4 = 0x3, CHAN7_MUX_VDD = 0x4, CHAN7_MUX_CH7_INPUT = 0x7, }; struct meson_sar_adc_data { bool has_bl30_integration; unsigned int resolution; const char *name; }; struct meson_sar_adc_priv { struct regmap *regmap; struct regulator *vref; const struct meson_sar_adc_data *data; struct clk *clkin; struct clk *core_clk; struct clk *sana_clk; struct clk *adc_sel_clk; struct clk *adc_clk; struct clk_gate clk_gate; struct clk *adc_div_clk; struct clk_divider clk_div; struct completion done; int calibbias; int calibscale; }; static const struct regmap_config meson_sar_adc_regmap_config = { .reg_bits = 8, .val_bits = 32, .reg_stride = 4, .max_register = MESON_SAR_ADC_REG13, }; static unsigned int meson_sar_adc_get_fifo_count(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); u32 regval; regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val); return FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval); } static int meson_sar_adc_calib_val(struct iio_dev *indio_dev, int val) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int tmp; /* use val_calib = scale * val_raw + offset calibration function */ tmp = div_s64((s64)val * priv->calibscale, MILLION) + priv->calibbias; return clamp(tmp, 0, (1 << priv->data->resolution) - 1); } static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int regval, timeout = 10000; /* * NOTE: we need a small delay before reading the status, otherwise * the sample engine may not have started internally (which would * seem to us that sampling is already finished). */ do { udelay(1); regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val); } while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--); if (timeout < 0) return -ETIMEDOUT; return 0; } static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, int *val) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int regval, fifo_chan, fifo_val, count; if(!wait_for_completion_timeout(&priv->done, msecs_to_jiffies(MESON_SAR_ADC_TIMEOUT))) return -ETIMEDOUT; count = meson_sar_adc_get_fifo_count(indio_dev); if (count != 1) { dev_err(&indio_dev->dev, "ADC FIFO has %d element(s) instead of one\n", count); return -EINVAL; } regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, ®val); fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval); if (fifo_chan != chan->channel) { dev_err(&indio_dev->dev, "ADC FIFO entry belongs to channel %d instead of %d\n", fifo_chan, chan->channel); return -EINVAL; } fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK, regval); fifo_val &= GENMASK(priv->data->resolution - 1, 0); *val = meson_sar_adc_calib_val(indio_dev, fifo_val); return 0; } static void meson_sar_adc_set_averaging(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, enum meson_sar_adc_avg_mode mode, enum meson_sar_adc_num_samples samples) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int val, channel = chan->channel; val = samples << MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(channel); regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL, MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(channel), val); val = mode << MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(channel); regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL, MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(channel), val); } static void meson_sar_adc_enable_channel(struct iio_dev *indio_dev, const struct iio_chan_spec *chan) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); u32 regval; /* * the SAR ADC engine allows sampling multiple channels at the same * time. to keep it simple we're only working with one *internal* * channel, which starts counting at index 0 (which means: count = 1). */ regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, 0); regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST, MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, regval); /* map channel index 0 to the channel which we want to read */ regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0), chan->channel); regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST, MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0), regval); regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK, chan->channel); regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW, MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK, regval); regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK, chan->channel); regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW, MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK, regval); if (chan->channel == 6) regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10, MESON_SAR_ADC_DELTA_10_TEMP_SEL, 0); } static void meson_sar_adc_set_chan7_mux(struct iio_dev *indio_dev, enum meson_sar_adc_chan7_mux_sel sel) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); u32 regval; regval = FIELD_PREP(MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, sel); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3, MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, regval); usleep_range(10, 20); } static void meson_sar_adc_start_sample_engine(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); reinit_completion(&priv->done); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0, MESON_SAR_ADC_REG0_FIFO_IRQ_EN, MESON_SAR_ADC_REG0_FIFO_IRQ_EN); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0, MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE, MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0, MESON_SAR_ADC_REG0_SAMPLING_START, MESON_SAR_ADC_REG0_SAMPLING_START); } static void meson_sar_adc_stop_sample_engine(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0, MESON_SAR_ADC_REG0_FIFO_IRQ_EN, 0); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0, MESON_SAR_ADC_REG0_SAMPLING_STOP, MESON_SAR_ADC_REG0_SAMPLING_STOP); /* wait until all modules are stopped */ meson_sar_adc_wait_busy_clear(indio_dev); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0, MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE, 0); } static int meson_sar_adc_lock(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int val, timeout = 10000; mutex_lock(&indio_dev->mlock); if (priv->data->has_bl30_integration) { /* prevent BL30 from using the SAR ADC while we are using it */ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY, MESON_SAR_ADC_DELAY_KERNEL_BUSY, MESON_SAR_ADC_DELAY_KERNEL_BUSY); /* * wait until BL30 releases it's lock (so we can use the SAR * ADC) */ do { udelay(1); regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val); } while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--); if (timeout < 0) return -ETIMEDOUT; } return 0; } static void meson_sar_adc_unlock(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); if (priv->data->has_bl30_integration) /* allow BL30 to use the SAR ADC again */ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY, MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0); mutex_unlock(&indio_dev->mlock); } static void meson_sar_adc_clear_fifo(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int count; for (count = 0; count < MESON_SAR_ADC_MAX_FIFO_SIZE; count++) { if (!meson_sar_adc_get_fifo_count(indio_dev)) break; regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, 0); } } static int meson_sar_adc_get_sample(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, enum meson_sar_adc_avg_mode avg_mode, enum meson_sar_adc_num_samples avg_samples, int *val) { int ret; ret = meson_sar_adc_lock(indio_dev); if (ret) return ret; /* clear the FIFO to make sure we're not reading old values */ meson_sar_adc_clear_fifo(indio_dev); meson_sar_adc_set_averaging(indio_dev, chan, avg_mode, avg_samples); meson_sar_adc_enable_channel(indio_dev, chan); meson_sar_adc_start_sample_engine(indio_dev); ret = meson_sar_adc_read_raw_sample(indio_dev, chan, val); meson_sar_adc_stop_sample_engine(indio_dev); meson_sar_adc_unlock(indio_dev); if (ret) { dev_warn(indio_dev->dev.parent, "failed to read sample for channel %d: %d\n", chan->channel, ret); return ret; } return IIO_VAL_INT; } static int meson_sar_adc_iio_info_read_raw(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, int *val, int *val2, long mask) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_RAW: return meson_sar_adc_get_sample(indio_dev, chan, NO_AVERAGING, ONE_SAMPLE, val); break; case IIO_CHAN_INFO_AVERAGE_RAW: return meson_sar_adc_get_sample(indio_dev, chan, MEAN_AVERAGING, EIGHT_SAMPLES, val); break; case IIO_CHAN_INFO_SCALE: ret = regulator_get_voltage(priv->vref); if (ret < 0) { dev_err(indio_dev->dev.parent, "failed to get vref voltage: %d\n", ret); return ret; } *val = ret / 1000; *val2 = priv->data->resolution; return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_CALIBBIAS: *val = priv->calibbias; return IIO_VAL_INT; case IIO_CHAN_INFO_CALIBSCALE: *val = priv->calibscale / MILLION; *val2 = priv->calibscale % MILLION; return IIO_VAL_INT_PLUS_MICRO; default: return -EINVAL; } } static int meson_sar_adc_clk_init(struct iio_dev *indio_dev, void __iomem *base) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); struct clk_init_data init; const char *clk_parents[1]; init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%s#adc_div", of_node_full_name(indio_dev->dev.of_node)); init.flags = 0; init.ops = &clk_divider_ops; clk_parents[0] = __clk_get_name(priv->clkin); init.parent_names = clk_parents; init.num_parents = 1; priv->clk_div.reg = base + MESON_SAR_ADC_REG3; priv->clk_div.shift = MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT; priv->clk_div.width = MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH; priv->clk_div.hw.init = &init; priv->clk_div.flags = 0; priv->adc_div_clk = devm_clk_register(&indio_dev->dev, &priv->clk_div.hw); if (WARN_ON(IS_ERR(priv->adc_div_clk))) return PTR_ERR(priv->adc_div_clk); init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%s#adc_en", of_node_full_name(indio_dev->dev.of_node)); init.flags = CLK_SET_RATE_PARENT; init.ops = &clk_gate_ops; clk_parents[0] = __clk_get_name(priv->adc_div_clk); init.parent_names = clk_parents; init.num_parents = 1; priv->clk_gate.reg = base + MESON_SAR_ADC_REG3; priv->clk_gate.bit_idx = fls(MESON_SAR_ADC_REG3_CLK_EN); priv->clk_gate.hw.init = &init; priv->adc_clk = devm_clk_register(&indio_dev->dev, &priv->clk_gate.hw); if (WARN_ON(IS_ERR(priv->adc_clk))) return PTR_ERR(priv->adc_clk); return 0; } static int meson_sar_adc_init(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int regval, ret; /* * make sure we start at CH7 input since the other muxes are only used * for internal calibration. */ meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT); if (priv->data->has_bl30_integration) { /* * leave sampling delay and the input clocks as configured by * BL30 to make sure BL30 gets the values it expects when * reading the temperature sensor. */ regmap_read(priv->regmap, MESON_SAR_ADC_REG3, ®val); if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED) return 0; } meson_sar_adc_stop_sample_engine(indio_dev); /* update the channel 6 MUX to select the temperature sensor */ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0, MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL, MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL); /* disable all channels by default */ regmap_write(priv->regmap, MESON_SAR_ADC_CHAN_LIST, 0x0); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3, MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE, 0); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3, MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY, MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY); /* delay between two samples = (10+1) * 1uS */ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY, MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK, FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK, 10)); regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY, MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK, FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK, 0)); /* delay between two samples = (10+1) * 1uS */ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY, MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK, FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK, 10)); regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY, MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK, FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK, 1)); ret = clk_set_parent(priv->adc_sel_clk, priv->clkin); if (ret) { dev_err(indio_dev->dev.parent, "failed to set adc parent to clkin\n"); return ret; } ret = clk_set_rate(priv->adc_clk, 1200000); if (ret) { dev_err(indio_dev->dev.parent, "failed to set adc clock rate\n"); return ret; } return 0; } static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int ret; u32 regval; ret = meson_sar_adc_lock(indio_dev); if (ret) goto err_lock; ret = regulator_enable(priv->vref); if (ret < 0) { dev_err(indio_dev->dev.parent, "failed to enable vref regulator\n"); goto err_vref; } ret = clk_prepare_enable(priv->core_clk); if (ret) { dev_err(indio_dev->dev.parent, "failed to enable core clk\n"); goto err_core_clk; } ret = clk_prepare_enable(priv->sana_clk); if (ret) { dev_err(indio_dev->dev.parent, "failed to enable sana clk\n"); goto err_sana_clk; } regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0, MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11, MESON_SAR_ADC_REG11_BANDGAP_EN, MESON_SAR_ADC_REG11_BANDGAP_EN); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3, MESON_SAR_ADC_REG3_ADC_EN, MESON_SAR_ADC_REG3_ADC_EN); udelay(5); ret = clk_prepare_enable(priv->adc_clk); if (ret) { dev_err(indio_dev->dev.parent, "failed to enable adc clk\n"); goto err_adc_clk; } meson_sar_adc_unlock(indio_dev); return 0; err_adc_clk: regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3, MESON_SAR_ADC_REG3_ADC_EN, 0); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11, MESON_SAR_ADC_REG11_BANDGAP_EN, 0); clk_disable_unprepare(priv->sana_clk); err_sana_clk: clk_disable_unprepare(priv->core_clk); err_core_clk: regulator_disable(priv->vref); err_vref: meson_sar_adc_unlock(indio_dev); err_lock: return ret; } static int meson_sar_adc_hw_disable(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int ret; ret = meson_sar_adc_lock(indio_dev); if (ret) return ret; clk_disable_unprepare(priv->adc_clk); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3, MESON_SAR_ADC_REG3_ADC_EN, 0); regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11, MESON_SAR_ADC_REG11_BANDGAP_EN, 0); clk_disable_unprepare(priv->sana_clk); clk_disable_unprepare(priv->core_clk); regulator_disable(priv->vref); meson_sar_adc_unlock(indio_dev); return 0; } static irqreturn_t meson_sar_adc_irq(int irq, void *data) { struct iio_dev *indio_dev = data; struct meson_sar_adc_priv *priv = iio_priv(indio_dev); unsigned int cnt, threshold; u32 regval; regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val); cnt = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval); threshold = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval); if (cnt < threshold) return IRQ_NONE; complete(&priv->done); return IRQ_HANDLED; } static int meson_sar_adc_calib(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); int ret, nominal0, nominal1, value0, value1; /* use points 25% and 75% for calibration */ nominal0 = (1 << priv->data->resolution) / 4; nominal1 = (1 << priv->data->resolution) * 3 / 4; meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_DIV4); usleep_range(10, 20); ret = meson_sar_adc_get_sample(indio_dev, &meson_sar_adc_iio_channels[7], MEAN_AVERAGING, EIGHT_SAMPLES, &value0); if (ret < 0) goto out; meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_MUL3_DIV4); usleep_range(10, 20); ret = meson_sar_adc_get_sample(indio_dev, &meson_sar_adc_iio_channels[7], MEAN_AVERAGING, EIGHT_SAMPLES, &value1); if (ret < 0) goto out; if (value1 <= value0) { ret = -EINVAL; goto out; } priv->calibscale = div_s64((nominal1 - nominal0) * (s64)MILLION, value1 - value0); priv->calibbias = nominal0 - div_s64((s64)value0 * priv->calibscale, MILLION); ret = 0; out: meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT); return ret; } static const struct iio_info meson_sar_adc_iio_info = { .read_raw = meson_sar_adc_iio_info_read_raw, .driver_module = THIS_MODULE, }; static const struct meson_sar_adc_data meson_sar_adc_meson8_data = { .has_bl30_integration = false, .resolution = 10, .name = "meson-meson8-saradc", }; static const struct meson_sar_adc_data meson_sar_adc_meson8b_data = { .has_bl30_integration = false, .resolution = 10, .name = "meson-meson8b-saradc", }; static const struct meson_sar_adc_data meson_sar_adc_gxbb_data = { .has_bl30_integration = true, .resolution = 10, .name = "meson-gxbb-saradc", }; static const struct meson_sar_adc_data meson_sar_adc_gxl_data = { .has_bl30_integration = true, .resolution = 12, .name = "meson-gxl-saradc", }; static const struct meson_sar_adc_data meson_sar_adc_gxm_data = { .has_bl30_integration = true, .resolution = 12, .name = "meson-gxm-saradc", }; static const struct of_device_id meson_sar_adc_of_match[] = { { .compatible = "amlogic,meson8-saradc", .data = &meson_sar_adc_meson8_data, }, { .compatible = "amlogic,meson8b-saradc", .data = &meson_sar_adc_meson8b_data, }, { .compatible = "amlogic,meson-gxbb-saradc", .data = &meson_sar_adc_gxbb_data, }, { .compatible = "amlogic,meson-gxl-saradc", .data = &meson_sar_adc_gxl_data, }, { .compatible = "amlogic,meson-gxm-saradc", .data = &meson_sar_adc_gxm_data, }, {}, }; MODULE_DEVICE_TABLE(of, meson_sar_adc_of_match); static int meson_sar_adc_probe(struct platform_device *pdev) { struct meson_sar_adc_priv *priv; struct iio_dev *indio_dev; struct resource *res; void __iomem *base; const struct of_device_id *match; int irq, ret; indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv)); if (!indio_dev) { dev_err(&pdev->dev, "failed allocating iio device\n"); return -ENOMEM; } priv = iio_priv(indio_dev); init_completion(&priv->done); match = of_match_device(meson_sar_adc_of_match, &pdev->dev); priv->data = match->data; indio_dev->name = priv->data->name; indio_dev->dev.parent = &pdev->dev; indio_dev->dev.of_node = pdev->dev.of_node; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->info = &meson_sar_adc_iio_info; indio_dev->channels = meson_sar_adc_iio_channels; indio_dev->num_channels = ARRAY_SIZE(meson_sar_adc_iio_channels); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(base)) return PTR_ERR(base); irq = irq_of_parse_and_map(pdev->dev.of_node, 0); if (!irq) return -EINVAL; ret = devm_request_irq(&pdev->dev, irq, meson_sar_adc_irq, IRQF_SHARED, dev_name(&pdev->dev), indio_dev); if (ret) return ret; priv->regmap = devm_regmap_init_mmio(&pdev->dev, base, &meson_sar_adc_regmap_config); if (IS_ERR(priv->regmap)) return PTR_ERR(priv->regmap); priv->clkin = devm_clk_get(&pdev->dev, "clkin"); if (IS_ERR(priv->clkin)) { dev_err(&pdev->dev, "failed to get clkin\n"); return PTR_ERR(priv->clkin); } priv->core_clk = devm_clk_get(&pdev->dev, "core"); if (IS_ERR(priv->core_clk)) { dev_err(&pdev->dev, "failed to get core clk\n"); return PTR_ERR(priv->core_clk); } priv->sana_clk = devm_clk_get(&pdev->dev, "sana"); if (IS_ERR(priv->sana_clk)) { if (PTR_ERR(priv->sana_clk) == -ENOENT) { priv->sana_clk = NULL; } else { dev_err(&pdev->dev, "failed to get sana clk\n"); return PTR_ERR(priv->sana_clk); } } priv->adc_clk = devm_clk_get(&pdev->dev, "adc_clk"); if (IS_ERR(priv->adc_clk)) { if (PTR_ERR(priv->adc_clk) == -ENOENT) { priv->adc_clk = NULL; } else { dev_err(&pdev->dev, "failed to get adc clk\n"); return PTR_ERR(priv->adc_clk); } } priv->adc_sel_clk = devm_clk_get(&pdev->dev, "adc_sel"); if (IS_ERR(priv->adc_sel_clk)) { if (PTR_ERR(priv->adc_sel_clk) == -ENOENT) { priv->adc_sel_clk = NULL; } else { dev_err(&pdev->dev, "failed to get adc_sel clk\n"); return PTR_ERR(priv->adc_sel_clk); } } /* on pre-GXBB SoCs the SAR ADC itself provides the ADC clock: */ if (!priv->adc_clk) { ret = meson_sar_adc_clk_init(indio_dev, base); if (ret) return ret; } priv->vref = devm_regulator_get(&pdev->dev, "vref"); if (IS_ERR(priv->vref)) { dev_err(&pdev->dev, "failed to get vref regulator\n"); return PTR_ERR(priv->vref); } priv->calibscale = MILLION; ret = meson_sar_adc_init(indio_dev); if (ret) goto err; ret = meson_sar_adc_hw_enable(indio_dev); if (ret) goto err; ret = meson_sar_adc_calib(indio_dev); if (ret) dev_warn(&pdev->dev, "calibration failed\n"); platform_set_drvdata(pdev, indio_dev); ret = iio_device_register(indio_dev); if (ret) goto err_hw; return 0; err_hw: meson_sar_adc_hw_disable(indio_dev); err: return ret; } static int meson_sar_adc_remove(struct platform_device *pdev) { struct iio_dev *indio_dev = platform_get_drvdata(pdev); iio_device_unregister(indio_dev); return meson_sar_adc_hw_disable(indio_dev); } static int __maybe_unused meson_sar_adc_suspend(struct device *dev) { struct iio_dev *indio_dev = dev_get_drvdata(dev); return meson_sar_adc_hw_disable(indio_dev); } static int __maybe_unused meson_sar_adc_resume(struct device *dev) { struct iio_dev *indio_dev = dev_get_drvdata(dev); return meson_sar_adc_hw_enable(indio_dev); } static SIMPLE_DEV_PM_OPS(meson_sar_adc_pm_ops, meson_sar_adc_suspend, meson_sar_adc_resume); static struct platform_driver meson_sar_adc_driver = { .probe = meson_sar_adc_probe, .remove = meson_sar_adc_remove, .driver = { .name = "meson-saradc", .of_match_table = meson_sar_adc_of_match, .pm = &meson_sar_adc_pm_ops, }, }; module_platform_driver(meson_sar_adc_driver); MODULE_AUTHOR("Martin Blumenstingl "); MODULE_DESCRIPTION("Amlogic Meson SAR ADC driver"); MODULE_LICENSE("GPL v2");