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iio: adc: meson-saradc: enable the temperature sensor two more SoCs 

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.blumenstingl@googlemail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
hifive-unleashed-5.1
Martin Blumenstingl 2018-12-27 22:50:20 +01:00 committed by Jonathan Cameron
parent a4b475b1ab
commit b002bf5f8d
1 changed files with 33 additions and 0 deletions
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33
drivers/iio/adc/meson_saradc.c
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@ -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 = {