[PATCH v3 3/4] iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCs
Jonathan Cameron
jic23 at kernel.org
Sat Jan 21 04:52:16 PST 2017
On 19/01/17 14:58, Martin Blumenstingl wrote:
> This adds support for the SAR (Successive Approximation Register) ADC
> on the Amlogic Meson SoCs.
>
> The code is based on the public S805 (Meson8b) and S905 (GXBB)
> datasheets (see [0] and [1]), as well as by reading (various versions
> of) the vendor driver and by inspecting the registers on the vendor
> kernels of my testing-hardware.
>
> Currently the GXBB, GXL and GXM SoCs are supported. GXBB hardware has
> 10-bit ADC resolution, while GXL and GXM have 12-bit ADC resolution.
> The code was written to support older SoCs (Meson8 and Meson8b) as well,
> but due to lack of actual testing-hardware no of_device_id was added for
> these.
>
> Two "features" from the vendor driver are currently missing:
> - the vendor driver uses channel #7 for calibration (this improves the
> accuracy of the results - in my tests the results were less than 3%
> off without calibration compared to the vendor driver). Adding support
> for this should be easy, but is not required for most applications.
> - channel #6 is connected to the SoCs internal temperature sensor.
> Adding support for this is probably not so easy since (based on the
> u-boot sources) most SoC versions are using different registers and
> algorithms for the conversion from "ADC value" to temperature.
>
> Supported by the hardware but currently not supported by the driver:
> - reading multiple channels at the same time (the hardware has a FIFO
> buffer which stores multiple results)
> - continuous sampling (this would require a way to enable this
> individually because otherwise the ADC would be drawing power
> constantly)
> - interrupt support (similar to the vendor driver this new driver is
> polling the results. It is unclear if the IRQ-mode is supported on
> older (Meson6 or Meson8) hardware as well or if there are any errata)
>
> [0]
> http://dn.odroid.com/S805/Datasheet/S805_Datasheet%20V0.8%2020150126.pdf
> [1] http://dn.odroid.com/S905/DataSheet/S905_Public_Datasheet_V1.1.4.pdf
>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
> Tested-by: Neil Armstrong <narmstrong at baylibre.com>
Very nice. One really minor comment inline, that I'd only bother
dealing with should you be rolling a V4 for some other reason.
I'll take this if Rob / Mark are happy with the device tree bindings.
Give me a bump if we see nothing from them in the next week or so (or if
I miss it!)
thanks
Jonathan
> ---
> drivers/iio/adc/Kconfig | 12 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/meson_saradc.c | 916 +++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 929 insertions(+)
> create mode 100644 drivers/iio/adc/meson_saradc.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 9c8b558ba19e..86059b9b91bf 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -371,6 +371,18 @@ config MEN_Z188_ADC
> This driver can also be built as a module. If so, the module will be
> called men_z188_adc.
>
> +config MESON_SARADC
> + tristate "Amlogic Meson SAR ADC driver"
> + default ARCH_MESON
> + depends on OF && COMMON_CLK && (ARCH_MESON || COMPILE_TEST)
> + select REGMAP_MMIO
> + help
> + Say yes here to build support for the SAR ADC found in Amlogic Meson
> + SoCs.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called meson_saradc.
> +
> config MXS_LRADC
> tristate "Freescale i.MX23/i.MX28 LRADC"
> depends on (ARCH_MXS || COMPILE_TEST) && HAS_IOMEM
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index d36c4be8d1fc..de05b9e75f8f 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -36,6 +36,7 @@ obj-$(CONFIG_MCP320X) += mcp320x.o
> obj-$(CONFIG_MCP3422) += mcp3422.o
> obj-$(CONFIG_MEDIATEK_MT6577_AUXADC) += mt6577_auxadc.o
> obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
> +obj-$(CONFIG_MESON_SARADC) += meson_saradc.o
> obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o
> obj-$(CONFIG_NAU7802) += nau7802.o
> obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
> diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
> new file mode 100644
> index 000000000000..11a9686d2a9c
> --- /dev/null
> +++ b/drivers/iio/adc/meson_saradc.c
> @@ -0,0 +1,916 @@
> +/*
> + * Amlogic Meson Successive Approximation Register (SAR) A/D Converter
> + *
> + * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl at 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, ®val);
> +
> + return FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
> +}
> +
> +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 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, ®val);
> +
> + 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;
> +}
> +
> +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);
> +
> + 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_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);
> +
> + /* 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);
> +
> + /* 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;
> +
> + 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);
> +
> + /*
> + * 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;
> +
> + 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;
> +}
> +
> +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 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",
> +};
> +
> +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,
> + },
> + {},
> +};
> +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;
> +}
> +
> +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);
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
Slight perference for not bothing with the if def fun which
can go wrong, but instead use __maybe_unused.
Arnd is busy pushing this into lots of drivers and I think it
is neater.
I don't care about this enough to insist on a respin if it's all
that anyone comes up with.
> +static int 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 meson_sar_adc_resume(struct device *dev)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +
> + return meson_sar_adc_hw_enable(indio_dev);
> +}
> +#endif /* CONFIG_PM_SLEEP */
> +
> +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 at googlemail.com>");
> +MODULE_DESCRIPTION("Amlogic Meson SAR ADC driver");
> +MODULE_LICENSE("GPL v2");
>
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