cregit-Linux how code gets into the kernel

Release 4.11 drivers/iio/adc/meson_saradc.c

Directory: drivers/iio/adc
/*
 * Amlogic Meson Successive Approximation Register (SAR) A/D Converter
 *
 * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
 *
 * 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 <http://www.gnu.org/licenses/>.
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>


#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_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),           \
        .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 {
	
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;
};


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, &regval); return FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl45100.00%1100.00%
Total45100.00%1100.00%


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, &regval); } while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--); if (timeout < 0) return -ETIMEDOUT; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl75100.00%1100.00%
Total75100.00%1100.00%


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 ret, regval, fifo_chan, fifo_val, sum = 0, count = 0; ret = meson_sar_adc_wait_busy_clear(indio_dev); if (ret) return ret; while (meson_sar_adc_get_fifo_count(indio_dev) > 0 && count < MESON_SAR_ADC_MAX_FIFO_SIZE) { regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &regval); fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval); if (fifo_chan != chan->channel) continue; fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK, regval); fifo_val &= (BIT(priv->data->resolution) - 1); sum += fifo_val; count++; } if (!count) return -ENOENT; *val = sum / count; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl157100.00%1100.00%
Total157100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl94100.00%1100.00%
Total94100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl153100.00%1100.00%
Total153100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl57100.00%1100.00%
Total57100.00%1100.00%


static void meson_sar_adc_start_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_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); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl47100.00%1100.00%
Total47100.00%1100.00%


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_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); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl53100.00%1100.00%
Total53100.00%1100.00%


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); /* 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; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl94100.00%1100.00%
Total94100.00%1100.00%


static void meson_sar_adc_unlock(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); /* 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); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl43100.00%1100.00%
Total43100.00%1100.00%


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); } }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl59100.00%1100.00%
Total59100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl125100.00%1100.00%
Total125100.00%1100.00%


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; default: return -EINVAL; } }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl143100.00%1100.00%
Total143100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl320100.00%1100.00%
Total320100.00%1100.00%


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); /* * 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, &regval); 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; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl254100.00%1100.00%
Total254100.00%1100.00%


static int meson_sar_adc_hw_enable(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) 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; } 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; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl260100.00%1100.00%
Total260100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl100100.00%1100.00%
Total100100.00%1100.00%

static const struct iio_info meson_sar_adc_iio_info = { .read_raw = meson_sar_adc_iio_info_read_raw, .driver_module = THIS_MODULE, }; struct meson_sar_adc_data meson_sar_adc_gxbb_data = { .resolution = 10, .name = "meson-gxbb-saradc", }; struct meson_sar_adc_data meson_sar_adc_gxl_data = { .resolution = 12, .name = "meson-gxl-saradc", }; struct meson_sar_adc_data meson_sar_adc_gxm_data = { .resolution = 12, .name = "meson-gxm-saradc", }; static const struct of_device_id meson_sar_adc_of_match[] = { { .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 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); 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); 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); } ret = meson_sar_adc_init(indio_dev); if (ret) goto err; ret = meson_sar_adc_hw_enable(indio_dev); if (ret) goto err; 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; }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl652100.00%1100.00%
Total652100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl32100.00%1100.00%
Total32100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl28100.00%1100.00%
Total28100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl28100.00%1100.00%
Total28100.00%1100.00%

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 <martin.blumenstingl@googlemail.com>"); MODULE_DESCRIPTION("Amlogic Meson SAR ADC driver"); MODULE_LICENSE("GPL v2");

Overall Contributors

PersonTokensPropCommitsCommitProp
Martin Blumenstingl3759100.00%1100.00%
Total3759100.00%1100.00%
Directory: drivers/iio/adc
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.