On 15/12/16 22:48, Linus Walleij wrote:
> 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-vadc.o that contains both
> files: qcom-vadc-common.o and qcom-spmi-vadc.o.
>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-arm-msm@xxxxxxxxxxxxxxx
> Cc: Ivan T. Ivanov <iivanov.xz@xxxxxxxxx>
> Cc: Andy Gross <andy.gross@xxxxxxxxxx>
> Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Looks superficially fine, but I'm guessing will need a respin
as we have a fair bit of new stuff (and a couple of fixes) going
through this driver at the moment.
All but the two fixes I posted a few mins ago are in my testing
branch and should go to Greg once I have confirmed testing on
those two fixes.
Jonathan
> ---
> ChangeLog v1->v2:
> - No changes just reposting
> ---
> drivers/iio/adc/Makefile | 3 +-
> drivers/iio/adc/qcom-spmi-vadc.c | 95 +++-----------------------------------
> drivers/iio/adc/qcom-vadc-common.c | 38 +++++++++++++++
> drivers/iio/adc/qcom-vadc-common.h | 69 +++++++++++++++++++++++++++
> 4 files changed, 116 insertions(+), 89 deletions(-)
> create mode 100644 drivers/iio/adc/qcom-vadc-common.c
> create mode 100644 drivers/iio/adc/qcom-vadc-common.h
>
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 7a40c04c311f..f9468d228b1e 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -38,7 +38,8 @@ obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o
> obj-$(CONFIG_NAU7802) += nau7802.o
> obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
> obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
> -obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
> +qcom-vadc-y := qcom-vadc-common.o
> +obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-vadc.o qcom-spmi-vadc.o
> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
> obj-$(CONFIG_STX104) += stx104.o
> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
> diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c
> index c2babe50a0d8..74d21afa34a9 100644
> --- a/drivers/iio/adc/qcom-spmi-vadc.c
> +++ b/drivers/iio/adc/qcom-spmi-vadc.c
> @@ -28,6 +28,8 @@
>
> #include <dt-bindings/iio/qcom,spmi-vadc.h>
>
> +#include "qcom-vadc-common.h"
> +
> /* VADC register and bit definitions */
> #define VADC_REVISION2 0x1
> #define VADC_REVISION2_SUPPORTED_VADC 1
> @@ -75,69 +77,9 @@
>
> #define VADC_DATA 0x60 /* 16 bits */
>
> -#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_UV 1800000
> -
> -#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 VADC_CHAN_MIN VADC_USBIN
> #define VADC_CHAN_MAX VADC_LR_MUX3_BUF_PU1_PU2_XO_THERM
>
> -/*
> - * 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;
> -};
> -
> /**
> * struct vadc_channel_prop - VADC channel property.
> * @channel: channel number, refer to the channel list.
> @@ -471,33 +413,10 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc)
> static s32 vadc_calibrate(struct vadc_priv *vadc,
> const struct vadc_channel_prop *prop, u16 adc_code)
> {
> - const struct vadc_prescale_ratio *prescale;
> - s64 voltage;
> -
> - voltage = adc_code - vadc->graph[prop->calibration].gnd;
> - voltage *= vadc->graph[prop->calibration].dx;
> - voltage = div64_s64(voltage, vadc->graph[prop->calibration].dy);
> -
> - if (prop->calibration == VADC_CALIB_ABSOLUTE)
> - voltage += vadc->graph[prop->calibration].dx;
> -
> - if (voltage < 0)
> - voltage = 0;
> -
> - prescale = &vadc_prescale_ratios[prop->prescale];
> -
> - voltage = voltage * prescale->den;
> -
> - return div64_s64(voltage, prescale->num);
> -}
> -
> -static int vadc_decimation_from_dt(u32 value)
> -{
> - if (!is_power_of_2(value) || value < VADC_DECIMATION_MIN ||
> - value > VADC_DECIMATION_MAX)
> - return -EINVAL;
> -
> - return __ffs64(value / VADC_DECIMATION_MIN);
> + return qcom_vadc_calibrate(&vadc_prescale_ratios[prop->prescale],
> + &vadc->graph[prop->calibration],
> + (prop->calibration == VADC_CALIB_ABSOLUTE),
> + adc_code);
> }
>
> static int vadc_prescaling_from_dt(u32 num, u32 den)
> @@ -752,7 +671,7 @@ static int vadc_get_dt_channel_data(struct device *dev,
>
> ret = of_property_read_u32(node, "qcom,decimation", &value);
> if (!ret) {
> - ret = vadc_decimation_from_dt(value);
> + ret = qcom_vadc_decimation_from_dt(value);
> if (ret < 0) {
> dev_err(dev, "%02x invalid decimation %d\n",
> chan, value);
> diff --git a/drivers/iio/adc/qcom-vadc-common.c b/drivers/iio/adc/qcom-vadc-common.c
> new file mode 100644
> index 000000000000..f67fc5e2a702
> --- /dev/null
> +++ b/drivers/iio/adc/qcom-vadc-common.c
> @@ -0,0 +1,38 @@
> +#include <linux/kernel.h>
> +#include <linux/bitops.h>
> +#include <linux/math64.h>
> +#include <linux/log2.h>
> +#include <linux/err.h>
> +
> +#include "qcom-vadc-common.h"
> +
> +s32 qcom_vadc_calibrate(const struct vadc_prescale_ratio *prescale,
> + const struct vadc_linear_graph *graph,
> + bool absolute,
> + u16 adc_code)
> +{
> + s64 voltage;
> +
> + voltage = adc_code - graph->gnd;
> + voltage *= graph->dx;
> + voltage = div64_s64(voltage, graph->dy);
> +
> + if (absolute)
> + voltage += graph->dx;
> +
> + if (voltage < 0)
> + voltage = 0;
> +
> + voltage = voltage * prescale->den;
> +
> + return div64_s64(voltage, prescale->num);
> +}
> +
> +int qcom_vadc_decimation_from_dt(u32 value)
> +{
> + if (!is_power_of_2(value) || value < VADC_DECIMATION_MIN ||
> + value > VADC_DECIMATION_MAX)
> + return -EINVAL;
> +
> + return __ffs64(value / VADC_DECIMATION_MIN);
> +}
> diff --git a/drivers/iio/adc/qcom-vadc-common.h b/drivers/iio/adc/qcom-vadc-common.h
> new file mode 100644
> index 000000000000..b41cb501eef8
> --- /dev/null
> +++ b/drivers/iio/adc/qcom-vadc-common.h
> @@ -0,0 +1,69 @@
> +/*
> + * Code shared between the different Qualcomm PMIC voltage ADCs
> + */
> +
> +#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_UV 1800000
> +
> +#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
> +
> +/*
> + * 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;
> +};
> +
> +s32 qcom_vadc_calibrate(const struct vadc_prescale_ratio *prescale,
> + const struct vadc_linear_graph *graph,
> + bool absolute,
> + u16 adc_code);
> +int qcom_vadc_decimation_from_dt(u32 value);
>
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