[PATCH 2/3 v2] iio: adc: break out common code from SPMI VADC

[PATCH 2/3 v2] iio: adc: break out common code from SPMI VADC

[Linus Walleij]

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-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Cc: linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Ivan T. Ivanov <iivanov.xz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Andy Gross <andy.gross-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Bjorn Andersson <bjorn.andersson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Stephen Boyd <sboyd-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Signed-off-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
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);
-- 
2.7.4

Re: [PATCH 2/3 v2] iio: adc: break out common code from SPMI VADC

[Jonathan Cameron]

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-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
> Cc: linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Cc: Ivan T. Ivanov <iivanov.xz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Cc: Andy Gross <andy.gross-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> Cc: Bjorn Andersson <bjorn.andersson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> Cc: Stephen Boyd <sboyd-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> Cc: Srinivas Kandagatla <srinivas.kandagatla-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> Signed-off-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
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);
> 

Re: [PATCH 2/3 v2] iio: adc: break out common code from SPMI VADC

[Linus Walleij]

On Fri, Dec 30, 2016 at 8:01 PM, Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
> 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-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
>> Cc: linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> Cc: Ivan T. Ivanov <iivanov.xz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> Cc: Andy Gross <andy.gross-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>> Cc: Bjorn Andersson <bjorn.andersson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>> Cc: Stephen Boyd <sboyd-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
>> Cc: Srinivas Kandagatla <srinivas.kandagatla-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>> Signed-off-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>
> 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.

I looked at the git and "testing"
contains a top commit named "guessing" fixing some 64bit
artithmetic (which looks correct) in the driver, shall I simply
rebase on top of that and hope for the best? :)

Yours,
Linus Walleij

Re: [PATCH 2/3 v2] iio: adc: break out common code from SPMI VADC

[jic23]

On 10.01.2017 08:54, Linus Walleij wrote:
> On Fri, Dec 30, 2016 at 8:01 PM, Jonathan Cameron <jic23@kernel.org> 
> wrote:
>> 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@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>
>>> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
>> 
>> 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.
> 
> I looked at the git and "testing"
> contains a top commit named "guessing" fixing some 64bit
> artithmetic (which looks correct) in the driver, shall I simply
> rebase on top of that and hope for the best? :)
I'm an idiot and pushed out the wrong branch.  Will fix up when
I get home and push one with a sensible patch title!
(It'll be the same content though - feel free to Ack that if
you like ;)

Not my best half asleep patch writing ;)

Jonathan
> 
> Yours,
> Linus Walleij
> --
> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 2/3 v2] iio: adc: break out common code from SPMI VADC

[Jonathan Cameron]

On 10/01/17 14:21, jic23@kernel.org wrote:
> On 10.01.2017 08:54, Linus Walleij wrote:
>> On Fri, Dec 30, 2016 at 8:01 PM, Jonathan Cameron <jic23@kernel.org> wrote:
>>> 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@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>
>>>> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
>>>
>>> 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.
>>
>> I looked at the git and "testing"
>> contains a top commit named "guessing" fixing some 64bit
>> artithmetic (which looks correct) in the driver, shall I simply
>> rebase on top of that and hope for the best? :)
> I'm an idiot and pushed out the wrong branch.  Will fix up when
> I get home and push one with a sensible patch title!
> (It'll be the same content though - feel free to Ack that if
> you like ;)
> 
> Not my best half asleep patch writing ;)
Fixed... It's called testing for a reason ;)

Jonathan
> 
> Jonathan
>>
>> Yours,
>> Linus Walleij
>> -- 
>> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
>> the body of a message to majordomo@vger.kernel.org
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> -- 
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