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author | Linus Walleij <linus.walleij@linaro.org> | 2017-04-04 14:08:18 +0200 |
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committer | Jonathan Cameron <jic23@kernel.org> | 2017-04-08 18:40:49 +0200 |
commit | e932d4f041a487debc31e98c8b70baa861532272 (patch) | |
tree | c71d4fd809c4c3ba9fd7c4ee739e4784f2b4abc2 /drivers/iio/adc/qcom-vadc-common.h | |
parent | iio: xoadc: augment DT bindings a bit (diff) | |
download | linux-e932d4f041a487debc31e98c8b70baa861532272.tar.xz linux-e932d4f041a487debc31e98c8b70baa861532272.zip |
iio: adc: break out common code from SPMI VADC
The SPMI VADC and the earlier XOADC share a subset of
common code, so to be able to use the same code in both
drivers, we break out a separate file with the common code,
prefix exported functions that are no longer static with
qcom_* and bake an object qcom-spmi-vadc.o that contains both
files: qcom-vadc-common.o and qcom-spmi-vadc-core.o.
As we need to follow the procedure for making a kernel module
or compiled in object from several files, but still want to
produce the same module name, rename the qcom-spmi-vadc.c
file to qcom-spmi-vadc-core.c so we can bake the two objects
into qcom-spmi-vadc.o
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: Ivan T. Ivanov <iivanov.xz@gmail.com>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Rama Krishna Phani A <rphani@codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/adc/qcom-vadc-common.h')
-rw-r--r-- | drivers/iio/adc/qcom-vadc-common.h | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/drivers/iio/adc/qcom-vadc-common.h b/drivers/iio/adc/qcom-vadc-common.h new file mode 100644 index 000000000000..63c872a70adc --- /dev/null +++ b/drivers/iio/adc/qcom-vadc-common.h @@ -0,0 +1,108 @@ +/* + * Code shared between the different Qualcomm PMIC voltage ADCs + */ + +#ifndef QCOM_VADC_COMMON_H +#define QCOM_VADC_COMMON_H + +#define VADC_CONV_TIME_MIN_US 2000 +#define VADC_CONV_TIME_MAX_US 2100 + +/* Min ADC code represents 0V */ +#define VADC_MIN_ADC_CODE 0x6000 +/* Max ADC code represents full-scale range of 1.8V */ +#define VADC_MAX_ADC_CODE 0xa800 + +#define VADC_ABSOLUTE_RANGE_UV 625000 +#define VADC_RATIOMETRIC_RANGE 1800 + +#define VADC_DEF_PRESCALING 0 /* 1:1 */ +#define VADC_DEF_DECIMATION 0 /* 512 */ +#define VADC_DEF_HW_SETTLE_TIME 0 /* 0 us */ +#define VADC_DEF_AVG_SAMPLES 0 /* 1 sample */ +#define VADC_DEF_CALIB_TYPE VADC_CALIB_ABSOLUTE + +#define VADC_DECIMATION_MIN 512 +#define VADC_DECIMATION_MAX 4096 + +#define VADC_HW_SETTLE_DELAY_MAX 10000 +#define VADC_AVG_SAMPLES_MAX 512 + +#define KELVINMIL_CELSIUSMIL 273150 + +#define PMI_CHG_SCALE_1 -138890 +#define PMI_CHG_SCALE_2 391750000000LL + +/** + * struct vadc_map_pt - Map the graph representation for ADC channel + * @x: Represent the ADC digitized code. + * @y: Represent the physical data which can be temperature, voltage, + * resistance. + */ +struct vadc_map_pt { + s32 x; + s32 y; +}; + +/* + * VADC_CALIB_ABSOLUTE: uses the 625mV and 1.25V as reference channels. + * VADC_CALIB_RATIOMETRIC: uses the reference voltage (1.8V) and GND for + * calibration. + */ +enum vadc_calibration { + VADC_CALIB_ABSOLUTE = 0, + VADC_CALIB_RATIOMETRIC +}; + +/** + * struct vadc_linear_graph - Represent ADC characteristics. + * @dy: numerator slope to calculate the gain. + * @dx: denominator slope to calculate the gain. + * @gnd: A/D word of the ground reference used for the channel. + * + * Each ADC device has different offset and gain parameters which are + * computed to calibrate the device. + */ +struct vadc_linear_graph { + s32 dy; + s32 dx; + s32 gnd; +}; + +/** + * struct vadc_prescale_ratio - Represent scaling ratio for ADC input. + * @num: the inverse numerator of the gain applied to the input channel. + * @den: the inverse denominator of the gain applied to the input channel. + */ +struct vadc_prescale_ratio { + u32 num; + u32 den; +}; + +/** + * enum vadc_scale_fn_type - Scaling function to convert ADC code to + * physical scaled units for the channel. + * SCALE_DEFAULT: Default scaling to convert raw adc code to voltage (uV). + * SCALE_THERM_100K_PULLUP: Returns temperature in millidegC. + * Uses a mapping table with 100K pullup. + * SCALE_PMIC_THERM: Returns result in milli degree's Centigrade. + * SCALE_XOTHERM: Returns XO thermistor voltage in millidegC. + * SCALE_PMI_CHG_TEMP: Conversion for PMI CHG temp + */ +enum vadc_scale_fn_type { + SCALE_DEFAULT = 0, + SCALE_THERM_100K_PULLUP, + SCALE_PMIC_THERM, + SCALE_XOTHERM, + SCALE_PMI_CHG_TEMP, +}; + +int qcom_vadc_scale(enum vadc_scale_fn_type scaletype, + const struct vadc_linear_graph *calib_graph, + const struct vadc_prescale_ratio *prescale, + bool absolute, + u16 adc_code, int *result_mdec); + +int qcom_vadc_decimation_from_dt(u32 value); + +#endif /* QCOM_VADC_COMMON_H */ |