summaryrefslogtreecommitdiffstats
path: root/drivers/iio/adc/qcom-vadc-common.h
diff options
context:
space:
mode:
authorLinus Walleij <linus.walleij@linaro.org>2017-04-04 14:08:18 +0200
committerJonathan Cameron <jic23@kernel.org>2017-04-08 18:40:49 +0200
commite932d4f041a487debc31e98c8b70baa861532272 (patch)
treec71d4fd809c4c3ba9fd7c4ee739e4784f2b4abc2 /drivers/iio/adc/qcom-vadc-common.h
parentiio: xoadc: augment DT bindings a bit (diff)
downloadlinux-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.h108
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 */