On Thu, 27 Dec 2018 22:50:20 +0100
Martin Blumenstingl <martin.blumensti...@googlemail.com> wrote:
> Meson8b and Meson8m2 use the same logic to convert the ADC register
> value to celsius, which is different from Meson8:
> - Meson8 has different multiplier and divider values
> - Meson8 uses a 4-bit TSC (temperature sensor coefficient) which fits
> into the 4-bit field in the MESON_SAR_ADC_DELTA_10 register:
> MESON_SAR_ADC_DELTA_10_TS_C_MASK. Meson8b and Meson8m2 have a 5-bit
> TSC which requires writing the upper-most bit into the
> MESON_HHI_DPLL_TOP_0[9] register from the HHI register area.
>
> This adds support for the temperature sensor on the Meson8b and Meson8m2
> SoCs by implementing the logic to write the upper-most TSC bit into the
> HHI register area. The SoC-specific values (temperature_trimming_bits,
> temperature_multiplier, temperature_divider) are added - these simply
> integrate into the existing infrastructure (which was implemented for
> Meson8) and thus require no further changes to the existing temperature
> calculation logic.
>
> Signed-off-by: Martin Blumenstingl <martin.blumensti...@googlemail.com>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.
Thanks,
Jonathan
> ---
> drivers/iio/adc/meson_saradc.c | 33 +++++++++++++++++++++++++++++++++
> 1 file changed, 33 insertions(+)
>
> diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
> index 729becb2d3d9..f8600fbcdfe3 100644
> --- a/drivers/iio/adc/meson_saradc.c
> +++ b/drivers/iio/adc/meson_saradc.c
> @@ -26,6 +26,7 @@
> #include <linux/platform_device.h>
> #include <linux/regmap.h>
> #include <linux/regulator/consumer.h>
> +#include <linux/mfd/syscon.h>
>
> #define MESON_SAR_ADC_REG0 0x00
> #define MESON_SAR_ADC_REG0_PANEL_DETECT BIT(31)
> @@ -174,6 +175,9 @@
> #define MESON_SAR_ADC_EFUSE_BYTE3_UPPER_ADC_VAL
> GENMASK(6, 0)
> #define MESON_SAR_ADC_EFUSE_BYTE3_IS_CALIBRATED BIT(7)
>
> +#define MESON_HHI_DPLL_TOP_0 0x318
> +#define MESON_HHI_DPLL_TOP_0_TSC_BIT4 BIT(9)
> +
> /* for use with IIO_VAL_INT_PLUS_MICRO */
> #define MILLION 1000000
>
> @@ -280,6 +284,7 @@ struct meson_sar_adc_priv {
> struct completion done;
> int calibbias;
> int calibscale;
> + struct regmap *tsc_regmap;
> bool temperature_sensor_calibrated;
> u8 temperature_sensor_coefficient;
> u16 temperature_sensor_adc_val;
> @@ -727,6 +732,15 @@ static int meson_sar_adc_temp_sensor_init(struct iio_dev
> *indio_dev)
> return ret;
> }
>
> + priv->tsc_regmap =
> + syscon_regmap_lookup_by_phandle(indio_dev->dev.parent->of_node,
> + "amlogic,hhi-sysctrl");
> + if (IS_ERR(priv->tsc_regmap)) {
> + dev_err(indio_dev->dev.parent,
> + "failed to get amlogic,hhi-sysctrl regmap\n");
> + return PTR_ERR(priv->tsc_regmap);
> + }
> +
> read_len = MESON_SAR_ADC_EFUSE_BYTES;
> buf = nvmem_cell_read(temperature_calib, &read_len);
> if (IS_ERR(buf)) {
> @@ -861,6 +875,22 @@ static int meson_sar_adc_init(struct iio_dev *indio_dev)
> priv->temperature_sensor_coefficient);
> regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
> MESON_SAR_ADC_DELTA_10_TS_C_MASK, regval);
> +
> + if (priv->param->temperature_trimming_bits == 5) {
> + if (priv->temperature_sensor_coefficient & BIT(4))
> + regval = MESON_HHI_DPLL_TOP_0_TSC_BIT4;
> + else
> + regval = 0;
> +
> + /*
> + * bit [4] (the 5th bit when starting to count at 1)
> + * of the TSC is located in the HHI register area.
> + */
> + regmap_update_bits(priv->tsc_regmap,
> + MESON_HHI_DPLL_TOP_0,
> + MESON_HHI_DPLL_TOP_0_TSC_BIT4,
> + regval);
> + }
> } else {
> regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
> MESON_SAR_ADC_DELTA_10_TS_REVE1, 0);
> @@ -1064,6 +1094,9 @@ static const struct meson_sar_adc_param
> meson_sar_adc_meson8b_param = {
> .bandgap_reg = MESON_SAR_ADC_DELTA_10,
> .regmap_config = &meson_sar_adc_regmap_config_meson8,
> .resolution = 10,
> + .temperature_trimming_bits = 5,
> + .temperature_multiplier = 10,
> + .temperature_divider = 32,
> };
>
> static const struct meson_sar_adc_param meson_sar_adc_gxbb_param = {
