[PATCH v3 0/2] Intial support for voltage ADC

[PATCH v3 0/2] Intial support for voltage ADC

[Stanimir Varbanov]

Changes since v2:

 - fixes per comments from Hartmut Knaack and Jonathan Cameron.
 - now register through IIO core only ADC channels described in DT.
 - register TEMP_DIE channel as IIO_TEMP type and as processed return value.
 - implement INFO_RAW and INFO_SCALE masks support in order to avoid losing 
   ADC precision.
 - various cleanups.

-------------------------------------------------------------------------------
Changes since v1:

 - the review comments from Peter Meerwald and Hartmut Knaack are taken into
   account
 - the driver private sysfs attributes are dropped out.
 - dt binding document is changed in the section of adc channel nodes - now the
   adc channel number is represented by "reg" property.
 - various cleanups found during preparation of version 2.

-------------------------------------------------------------------------------
Introduce inital support for VADC inside Qualcomm SPMI PMICs.
The vadc driver is reworked version of the same downstream
driver but now it is implemented through Industrial IO core.

Stanimir Varbanov (2):
  iio: vadc: Qualcomm SPMI PMIC voltage ADC driver
  DT: iio: vadc: document dt binding

 .../devicetree/bindings/iio/adc/qcom,spmi-vadc.txt |  130 +++
 drivers/iio/adc/Kconfig                            |   10 +
 drivers/iio/adc/Makefile                           |    1 +
 drivers/iio/adc/qcom-spmi-vadc.c                   | 1029 ++++++++++++++++++++
 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h      |  119 +++
 5 files changed, 1289 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
 create mode 100644 drivers/iio/adc/qcom-spmi-vadc.c
 create mode 100644 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h

[PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Stanimir Varbanov]

The voltage ADC is peripheral of Qualcomm SPMI PMIC chips. It has
15bits resolution and register space inside PMIC accessible across
SPMI bus.

The vadc driver registers itself through IIO interface.

Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
---
 drivers/iio/adc/Kconfig                       |   10 +
 drivers/iio/adc/Makefile                      |    1 +
 drivers/iio/adc/qcom-spmi-vadc.c              | 1029 +++++++++++++++++++++++++
 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h |  119 +++
 4 files changed, 1159 insertions(+), 0 deletions(-)
 create mode 100644 drivers/iio/adc/qcom-spmi-vadc.c
 create mode 100644 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 11b048a..ec48360 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -206,6 +206,16 @@ config NAU7802
 	  To compile this driver as a module, choose M here: the
 	  module will be called nau7802.
 
+config QCOM_SPMI_VADC
+	tristate "Qualcomm SPMI PMIC voltage ADC"
+	depends on SPMI
+	help
+	  Say yes here if you want support for the Qualcomm SPMI PMIC voltage ADC.
+
+	  The driver supports reading the HKADC, XOADC through the ADC AMUX arbiter.
+	  The driver supports reading the ADC through the AMUX channels for
+	  external pull-ups simultaneously.
+
 config TI_ADC081C
 	tristate "Texas Instruments ADC081C021/027"
 	depends on I2C
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index ad81b51..d5d18f4 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_MCP320X) += mcp320x.o
 obj-$(CONFIG_MCP3422) += mcp3422.o
 obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
 obj-$(CONFIG_NAU7802) += nau7802.o
+obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
 obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
 obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
 obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c
new file mode 100644
index 0000000..9e3e022
--- /dev/null
+++ b/drivers/iio/adc/qcom-spmi-vadc.c
@@ -0,0 +1,1029 @@
+/*
+ * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/log2.h>
+
+#include <dt-bindings/iio/qcom,spmi-pmic-vadc.h>
+
+/* VADC register and bit definitions */
+#define VADC_REVISION2				0x1
+#define VADC_REVISION2_SUPPORTED_VADC		1
+
+#define VADC_PERPH_TYPE				0x4
+#define VADC_PERPH_TYPE_ADC			8
+
+#define VADC_PERPH_SUBTYPE			0x5
+#define VADC_PERPH_SUBTYPE_VADC			1
+
+#define VADC_STATUS1				0x8
+#define VADC_STATUS1_OP_MODE			4
+#define VADC_STATUS1_REQ_STS			BIT(1)
+#define VADC_STATUS1_EOC			BIT(0)
+#define VADC_STATUS1_REQ_STS_EOC_MASK		0x3
+
+#define VADC_MODE_CTL				0x40
+#define VADC_OP_MODE_SHIFT			3
+#define VADC_OP_MODE_NORMAL			0
+#define VADC_AMUX_TRIM_EN			BIT(1)
+#define VADC_ADC_TRIM_EN			BIT(0)
+
+#define VADC_EN_CTL1				0x46
+#define VADC_EN_CTL1_SET			BIT(7)
+
+#define VADC_ADC_CH_SEL_CTL			0x48
+
+#define VADC_ADC_DIG_PARAM			0x50
+#define VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT	2
+
+#define VADC_HW_SETTLE_DELAY			0x51
+
+#define VADC_CONV_REQ				0x52
+#define VADC_CONV_REQ_SET			BIT(7)
+
+#define VADC_FAST_AVG_CTL			0x5a
+#define VADC_FAST_AVG_EN			0x5b
+#define VADC_FAST_AVG_EN_SET			BIT(7)
+
+#define VADC_ACCESS				0xd0
+#define VADC_ACCESS_DATA			0xa5
+
+#define VADC_PERH_RESET_CTL3			0xda
+#define VADC_FOLLOW_WARM_RB			BIT(2)
+
+#define VADC_DATA0				0x60
+#define VADC_DATA1				0x61
+
+#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 reference channels.
+ * VADC_CALIB_RATIOMETRIC: uses the reference Voltage/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.
+ * @vref: A/D word of the voltage reference used for the channel.
+ * @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 vref;
+	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.
+ * @calibration: calibration type.
+ * @decimation: sampling rate supported for the channel.
+ * @prescale: channel scaling performed on the input signal.
+ * @hw_settle_time: the time between AMUX being configured and the
+ *	start of conversion.
+ * @avg_samples: ability to provide single result from the ADC
+ *	that is an average of multiple measurements.
+ */
+struct vadc_channel_prop {
+	unsigned int channel;
+	enum vadc_calibration calibration;
+	unsigned int decimation;
+	unsigned int prescale;
+	unsigned int hw_settle_time;
+	unsigned int avg_samples;
+};
+
+/**
+ * struct vadc_priv - VADC private structure.
+ * @regmap: pointer to struct regmap.
+ * @dev: pointer to struct device.
+ * @base: base address for the ADC peripheral.
+ * @nchannels: number of VADC channels.
+ * @chan_props: array of VADC channel properties.
+ * @iio_chans: array of IIO channels specification.
+ * @are_ref_measured: are reference points measured.
+ * @poll_eoc: use polling instead of interrupt.
+ * @complete: VADC result notification after interrupt is received.
+ * @graph: store parameters for calibration.
+ */
+struct vadc_priv {
+	struct regmap *regmap;
+	struct device *dev;
+	u16 base;
+	unsigned int nchannels;
+	struct vadc_channel_prop *chan_props;
+	struct iio_chan_spec *iio_chans;
+	bool are_ref_measured;
+	bool poll_eoc;
+	struct completion complete;
+	struct vadc_linear_graph graph[2];
+};
+
+static const struct vadc_prescale_ratio vadc_prescale_ratios[] = {
+	{.num =  1, .den =  1},
+	{.num =  1, .den =  3},
+	{.num =  1, .den =  4},
+	{.num =  1, .den =  6},
+	{.num =  1, .den = 20},
+	{.num =  1, .den =  8},
+	{.num = 10, .den = 81},
+	{.num =  1, .den = 10}
+};
+
+static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
+{
+	return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);
+}
+
+static int vadc_write(struct vadc_priv *vadc, u16 offset, u8 data)
+{
+	return regmap_write(vadc->regmap, vadc->base + offset, data);
+}
+
+static int vadc_reset(struct vadc_priv *vadc)
+{
+	u8 data;
+	int ret;
+
+	ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
+	if (ret)
+		return ret;
+
+	ret = vadc_read(vadc, VADC_PERH_RESET_CTL3, &data);
+	if (ret)
+		return ret;
+
+	ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
+	if (ret)
+		return ret;
+
+	data |= VADC_FOLLOW_WARM_RB;
+
+	return vadc_write(vadc, VADC_PERH_RESET_CTL3, data);
+}
+
+static int vadc_enable(struct vadc_priv *vadc, bool state)
+{
+	return vadc_write(vadc, VADC_EN_CTL1, state ? VADC_EN_CTL1_SET : 0);
+}
+
+#ifdef DEBUG
+static void vadc_show_status(struct vadc_priv *vadc)
+{
+	u8 mode, sta1, chan, dig, en, req;
+	int ret;
+
+	ret = vadc_read(vadc, VADC_MODE_CTL, &mode);
+	if (ret)
+		return;
+
+	ret = vadc_read(vadc, VADC_ADC_DIG_PARAM, &dig);
+	if (ret)
+		return;
+
+	ret = vadc_read(vadc, VADC_ADC_CH_SEL_CTL, &chan);
+	if (ret)
+		return;
+
+	ret = vadc_read(vadc, VADC_CONV_REQ, &req);
+	if (ret)
+		return;
+
+	ret = vadc_read(vadc, VADC_STATUS1, &sta1);
+	if (ret)
+		return;
+
+	ret = vadc_read(vadc, VADC_EN_CTL1, &en);
+	if (ret)
+		return;
+
+	dev_dbg(vadc->dev,
+		"mode:%02x en:%02x chan:%02x dig:%02x req:%02x sta1:%02x\n",
+		mode, en, chan, dig, req, sta1);
+}
+#else
+static void vadc_show_status(struct vadc_priv *vadc) {}
+#endif
+
+static int vadc_configure(struct vadc_priv *vadc,
+			  struct vadc_channel_prop *prop)
+{
+	u8 decimation, mode_ctrl;
+	int ret;
+
+	/* Mode selection */
+	mode_ctrl = (VADC_OP_MODE_NORMAL << VADC_OP_MODE_SHIFT) |
+		     VADC_ADC_TRIM_EN | VADC_AMUX_TRIM_EN;
+	ret = vadc_write(vadc, VADC_MODE_CTL, mode_ctrl);
+	if (ret)
+		return ret;
+
+	/* Channel selection */
+	ret = vadc_write(vadc, VADC_ADC_CH_SEL_CTL, prop->channel);
+	if (ret)
+		return ret;
+
+	/* Digital parameter setup */
+	decimation = prop->decimation << VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT;
+	ret = vadc_write(vadc, VADC_ADC_DIG_PARAM, decimation);
+	if (ret)
+		return ret;
+
+	/* HW settle time delay */
+	ret = vadc_write(vadc, VADC_HW_SETTLE_DELAY, prop->hw_settle_time);
+	if (ret)
+		return ret;
+
+	ret = vadc_write(vadc, VADC_FAST_AVG_CTL, prop->avg_samples);
+	if (ret)
+		return ret;
+
+	if (prop->avg_samples)
+		ret = vadc_write(vadc, VADC_FAST_AVG_EN, VADC_FAST_AVG_EN_SET);
+	else
+		ret = vadc_write(vadc, VADC_FAST_AVG_EN, 0);
+
+	return ret;
+}
+
+static int vadc_poll_wait_eoc(struct vadc_priv *vadc, unsigned int interval_us)
+{
+	unsigned int count, retry;
+	u8 sta1;
+	int ret;
+
+	retry = interval_us / VADC_CONV_TIME_MIN_US;
+
+	for (count = 0; count < retry; count++) {
+		ret = vadc_read(vadc, VADC_STATUS1, &sta1);
+		if (ret)
+			return ret;
+
+		sta1 &= VADC_STATUS1_REQ_STS_EOC_MASK;
+		if (sta1 == VADC_STATUS1_EOC)
+			return 0;
+
+		usleep_range(VADC_CONV_TIME_MIN_US, VADC_CONV_TIME_MAX_US);
+	}
+
+	vadc_show_status(vadc);
+
+	return -ETIMEDOUT;
+}
+
+static int vadc_read_result(struct vadc_priv *vadc, s32 *data)
+{
+	u8 lsb, msb;
+	int ret;
+
+	ret = vadc_read(vadc, VADC_DATA0, &lsb);
+	if (ret)
+		return ret;
+
+	ret = vadc_read(vadc, VADC_DATA1, &msb);
+	if (ret)
+		return ret;
+
+	*data = clamp_t(s32, (msb << 8) | lsb, VADC_MIN_ADC_CODE,
+			VADC_MAX_ADC_CODE);
+
+	return 0;
+}
+
+static struct vadc_channel_prop *vadc_get_channel(struct vadc_priv *vadc,
+						  int num)
+{
+	unsigned int i;
+
+	for (i = 0; i < vadc->nchannels; i++)
+		if (vadc->chan_props[i].channel == num)
+			return &vadc->chan_props[i];
+
+	dev_dbg(vadc->dev, "no such channel %02x\n", num);
+
+	return NULL;
+}
+
+static int vadc_do_conversion(struct vadc_priv *vadc,
+			      struct vadc_channel_prop *prop, s32 *data)
+{
+	unsigned int timeout;
+	int ret;
+
+	ret = vadc_configure(vadc, prop);
+	if (ret)
+		return ret;
+
+	if (!vadc->poll_eoc)
+		reinit_completion(&vadc->complete);
+
+	ret = vadc_enable(vadc, true);
+	if (ret)
+		return ret;
+
+	ret = vadc_write(vadc, VADC_CONV_REQ, VADC_CONV_REQ_SET);
+	if (ret)
+		goto err_disable;
+
+	timeout = BIT(prop->avg_samples) * VADC_CONV_TIME_MIN_US * 2;
+
+	if (vadc->poll_eoc) {
+		ret = vadc_poll_wait_eoc(vadc, timeout);
+	} else {
+		ret = wait_for_completion_timeout(&vadc->complete,
+						  msecs_to_jiffies(1000));
+		if (!ret) {
+			ret = -ETIMEDOUT;
+			goto err_disable;
+		}
+
+		/* double check conversion status */
+		ret = vadc_poll_wait_eoc(vadc, VADC_CONV_TIME_MIN_US * 2);
+		if (ret)
+			goto err_disable;
+	}
+
+	ret = vadc_read_result(vadc, data);
+
+err_disable:
+	vadc_enable(vadc, false);
+
+	if (ret)
+		dev_dbg(vadc->dev, "conversion failed\n");
+
+	return ret;
+}
+
+static int vadc_measure_ref_points(struct vadc_priv *vadc)
+{
+	struct vadc_channel_prop *prop;
+	s32 read_1, read_2;
+	int ret = -EINVAL;
+
+	vadc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE_UV;
+	vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;
+
+	prop = vadc_get_channel(vadc, VADC_REF_1250MV);
+	if (!prop)
+		goto err;
+
+	ret = vadc_do_conversion(vadc, prop, &read_1);
+	if (ret)
+		goto err;
+
+	/* Try with buffered 625mV channel first */
+	prop = vadc_get_channel(vadc, VADC_SPARE1);
+	if (!prop) {
+		prop = vadc_get_channel(vadc, VADC_REF_625MV);
+		if (!prop) {
+			ret = -EINVAL;
+			goto err;
+		}
+	}
+
+	ret = vadc_do_conversion(vadc, prop, &read_2);
+	if (ret)
+		goto err;
+
+	if (read_1 == read_2) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	vadc->graph[VADC_CALIB_ABSOLUTE].dy = read_1 - read_2;
+	vadc->graph[VADC_CALIB_ABSOLUTE].vref = read_1;
+	vadc->graph[VADC_CALIB_ABSOLUTE].gnd = read_2;
+
+	/* Ratiometric calibration */
+	prop = vadc_get_channel(vadc, VADC_VDD_VADC);
+	if (!prop) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	ret = vadc_do_conversion(vadc, prop, &read_1);
+	if (ret)
+		goto err;
+
+	prop = vadc_get_channel(vadc, VADC_GND_REF);
+	if (!prop) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	ret = vadc_do_conversion(vadc, prop, &read_2);
+	if (ret)
+		goto err;
+
+	if (read_1 == read_2) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	vadc->graph[VADC_CALIB_RATIOMETRIC].dy = read_1 - read_2;
+	vadc->graph[VADC_CALIB_RATIOMETRIC].vref = read_1;
+	vadc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_2;
+err:
+	if (ret)
+		dev_dbg(vadc->dev, "measure reference points failed\n");
+
+	return ret;
+}
+
+static s64 vadc_calibrate(struct vadc_priv *vadc,
+			  const struct vadc_channel_prop *prop, s32 adc_code)
+{
+	const struct vadc_prescale_ratio *prescale;
+	bool negative = false;
+	s64 voltage;
+
+	voltage = adc_code - vadc->graph[prop->calibration].gnd;
+	voltage *= vadc->graph[prop->calibration].dx;
+
+	if (voltage < 0) {
+		negative = true;
+		voltage = -voltage;
+	}
+
+	voltage = div_s64(voltage, vadc->graph[prop->calibration].dy);
+	if (negative)
+		voltage = -voltage;
+
+	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 div_s64(voltage, prescale->num);
+}
+
+static int vadc_decimation_from_dt(u32 value)
+{
+	if (!is_power_of_2(value) || !value || value < VADC_DECIMATION_MIN ||
+	    value > VADC_DECIMATION_MAX)
+		return -EINVAL;
+
+	return __ffs64(value / VADC_DECIMATION_MIN);
+}
+
+static int vadc_prescaling_from_dt(u32 num, u32 den)
+{
+	unsigned int pre;
+
+	for (pre = 0; pre < ARRAY_SIZE(vadc_prescale_ratios); pre++)
+		if (vadc_prescale_ratios[pre].num == num &&
+		    vadc_prescale_ratios[pre].den == den)
+			break;
+
+	if (pre == ARRAY_SIZE(vadc_prescale_ratios))
+		return -EINVAL;
+
+	return pre;
+}
+
+static int vadc_hw_settle_time_from_dt(u32 value)
+{
+	if ((value <= 1000 && value % 100) || (value > 1000 && value % 2000))
+		return -EINVAL;
+
+	if (value <= 1000)
+		value /= 100;
+	else
+		value = value / 2000 + 10;
+
+	return value;
+}
+
+static int vadc_avg_samples_from_dt(u32 value)
+{
+	if (!is_power_of_2(value) || !value || value > VADC_AVG_SAMPLES_MAX)
+		return -EINVAL;
+
+	return __ffs64(value);
+}
+
+static int vadc_read_raw(struct iio_dev *indio_dev,
+			 struct iio_chan_spec const *chan, int *val, int *val2,
+			 long mask)
+{
+	struct vadc_priv *vadc = iio_priv(indio_dev);
+	struct vadc_channel_prop *prop;
+	s32 adc_code;
+	int ret;
+
+	if (!vadc->are_ref_measured) {
+		ret = vadc_measure_ref_points(vadc);
+		if (ret)
+			return ret;
+
+		vadc->are_ref_measured = true;
+	}
+
+	if (mask == IIO_CHAN_INFO_PROCESSED || mask == IIO_CHAN_INFO_RAW) {
+		prop = &vadc->chan_props[chan->address];
+
+		ret = vadc_do_conversion(vadc, prop, &adc_code);
+		if (ret)
+			return ret;
+
+		*val = vadc_calibrate(vadc, prop, adc_code);
+	}
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		if (chan->type != IIO_TEMP && chan->channel != VADC_DIE_TEMP)
+			return -EINVAL;
+
+		/* 2mV/K, return milliCelsius */
+		*val /= 2;
+		*val -= KELVINMIL_CELSIUSMIL;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_RAW:
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = 1000;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info vadc_info = {
+	.read_raw = vadc_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+struct vadc_channels {
+	const char *datasheet_name;
+	unsigned int prescale_index;
+	enum iio_chan_type type;
+	long info_mask;
+};
+
+#define VADC_CHAN(_dname, _type, _mask, _pre)				\
+	[VADC_##_dname] = {						\
+		.datasheet_name = __stringify(_dname),			\
+		.prescale_index = _pre,					\
+		.type = _type,						\
+		.info_mask = _mask					\
+	},								\
+
+#define VADC_CHAN_TEMP(_dname, _pre)					\
+	VADC_CHAN(_dname, IIO_TEMP, BIT(IIO_CHAN_INFO_PROCESSED), _pre)	\
+
+#define VADC_CHAN_VOLT(_dname, _pre)					\
+	VADC_CHAN(_dname, IIO_VOLTAGE,					\
+		  BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),	\
+		  _pre)							\
+
+/*
+ * The array represents all possible ADC channels found in the supported PMICs.
+ * Every index in the array is equal to the channel number per datasheet. The
+ * gaps in the array should be treated as reserved channels.
+ */
+static const struct vadc_channels vadc_chans[] = {
+	VADC_CHAN_VOLT(USBIN, 4)
+	VADC_CHAN_VOLT(DCIN, 4)
+	VADC_CHAN_VOLT(VCHG_SNS, 3)
+	VADC_CHAN_VOLT(SPARE1_03, 1)
+	VADC_CHAN_VOLT(USB_ID_MV, 1)
+	VADC_CHAN_VOLT(VCOIN, 1)
+	VADC_CHAN_VOLT(VBAT_SNS, 1)
+	VADC_CHAN_VOLT(VSYS, 1)
+	VADC_CHAN_TEMP(DIE_TEMP, 0)
+	VADC_CHAN_VOLT(REF_625MV, 0)
+	VADC_CHAN_VOLT(REF_1250MV, 0)
+	VADC_CHAN_VOLT(CHG_TEMP, 0)
+	VADC_CHAN_VOLT(SPARE1, 0)
+	VADC_CHAN_VOLT(SPARE2, 0)
+	VADC_CHAN_VOLT(GND_REF, 0)
+	VADC_CHAN_VOLT(VDD_VADC, 0)
+
+	VADC_CHAN_VOLT(P_MUX1_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX2_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX3_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX4_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX5_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX6_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX7_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX8_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX9_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX10_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX11_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX12_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX13_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX14_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX15_1_1, 0)
+	VADC_CHAN_VOLT(P_MUX16_1_1, 0)
+
+	VADC_CHAN_VOLT(P_MUX1_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX2_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX3_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX4_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX5_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX6_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX7_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX8_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX9_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX10_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX11_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX12_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX13_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX14_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX15_1_3, 1)
+	VADC_CHAN_VOLT(P_MUX16_1_3, 1)
+
+	VADC_CHAN_VOLT(LR_MUX1_BAT_THERM, 0)
+	VADC_CHAN_VOLT(LR_MUX2_BAT_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX3_XO_THERM, 0)
+	VADC_CHAN_VOLT(LR_MUX4_AMUX_THM1, 0)
+	VADC_CHAN_VOLT(LR_MUX5_AMUX_THM2, 0)
+	VADC_CHAN_VOLT(LR_MUX6_AMUX_THM3, 0)
+	VADC_CHAN_VOLT(LR_MUX7_HW_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX8_AMUX_THM4, 0)
+	VADC_CHAN_VOLT(LR_MUX9_AMUX_THM5, 0)
+	VADC_CHAN_VOLT(LR_MUX10_USB_ID, 0)
+	VADC_CHAN_VOLT(AMUX_PU1, 0)
+	VADC_CHAN_VOLT(AMUX_PU2, 0)
+	VADC_CHAN_VOLT(LR_MUX3_BUF_XO_THERM, 0)
+
+	VADC_CHAN_VOLT(LR_MUX1_PU1_BAT_THERM, 0)
+	VADC_CHAN_VOLT(LR_MUX2_PU1_BAT_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX3_PU1_XO_THERM, 0)
+	VADC_CHAN_VOLT(LR_MUX4_PU1_AMUX_THM1, 0)
+	VADC_CHAN_VOLT(LR_MUX5_PU1_AMUX_THM2, 0)
+	VADC_CHAN_VOLT(LR_MUX6_PU1_AMUX_THM3, 0)
+	VADC_CHAN_VOLT(LR_MUX7_PU1_AMUX_HW_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX8_PU1_AMUX_THM4, 0)
+	VADC_CHAN_VOLT(LR_MUX9_PU1_AMUX_THM5, 0)
+	VADC_CHAN_VOLT(LR_MUX10_PU1_AMUX_USB_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_XO_THERM, 0)
+
+	VADC_CHAN_VOLT(LR_MUX1_PU2_BAT_THERM, 0)
+	VADC_CHAN_VOLT(LR_MUX2_PU2_BAT_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX3_PU2_XO_THERM, 0)
+	VADC_CHAN_VOLT(LR_MUX4_PU2_AMUX_THM1, 0)
+	VADC_CHAN_VOLT(LR_MUX5_PU2_AMUX_THM2, 0)
+	VADC_CHAN_VOLT(LR_MUX6_PU2_AMUX_THM3, 0)
+	VADC_CHAN_VOLT(LR_MUX7_PU2_AMUX_HW_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX8_PU2_AMUX_THM4, 0)
+	VADC_CHAN_VOLT(LR_MUX9_PU2_AMUX_THM5, 0)
+	VADC_CHAN_VOLT(LR_MUX10_PU2_AMUX_USB_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX3_BUF_PU2_XO_THERM, 0)
+
+	VADC_CHAN_VOLT(LR_MUX1_PU1_PU2_BAT_THERM, 0)
+	VADC_CHAN_VOLT(LR_MUX2_PU1_PU2_BAT_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX3_PU1_PU2_XO_THERM, 0)
+	VADC_CHAN_VOLT(LR_MUX4_PU1_PU2_AMUX_THM1, 0)
+	VADC_CHAN_VOLT(LR_MUX5_PU1_PU2_AMUX_THM2, 0)
+	VADC_CHAN_VOLT(LR_MUX6_PU1_PU2_AMUX_THM3, 0)
+	VADC_CHAN_VOLT(LR_MUX7_PU1_PU2_AMUX_HW_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX8_PU1_PU2_AMUX_THM4, 0)
+	VADC_CHAN_VOLT(LR_MUX9_PU1_PU2_AMUX_THM5, 0)
+	VADC_CHAN_VOLT(LR_MUX10_PU1_PU2_AMUX_USB_ID, 0)
+	VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_PU2_XO_THERM, 0)
+};
+
+static int vadc_get_dt_channel_data(struct device *dev,
+				    struct vadc_channel_prop *prop,
+				    struct device_node *node)
+{
+	const char *name = node->name;
+	u32 chan, value, varr[2];
+	int ret;
+
+	ret = of_property_read_u32(node, "reg", &chan);
+	if (ret) {
+		dev_dbg(dev, "invalid channel number %s\n", name);
+		return ret;
+	}
+
+	if (chan > VADC_CHAN_MAX || chan < VADC_CHAN_MIN) {
+		dev_dbg(dev, "%s invalid channel number %d\n", name, chan);
+		return -EINVAL;
+	}
+
+	/* the channel has DT description */
+	prop->channel = chan;
+
+	ret = of_property_read_u32(node, "qcom,decimation", &value);
+	if (!ret) {
+		ret = vadc_decimation_from_dt(value);
+		if (ret < 0) {
+			dev_dbg(dev, "%02x invalid decimation %d\n",
+				chan, value);
+			return ret;
+		}
+		prop->decimation = ret;
+	} else {
+		prop->decimation = VADC_DEF_DECIMATION;
+	}
+
+	ret = of_property_read_u32_array(node, "qcom,pre-scaling", varr, 2);
+	if (!ret) {
+		ret = vadc_prescaling_from_dt(varr[0], varr[1]);
+		if (ret < 0) {
+			dev_dbg(dev, "%02x invalid pre-scaling <%d %d>\n",
+				chan, varr[0], varr[1]);
+			return ret;
+		}
+		prop->prescale = ret;
+	} else {
+		prop->prescale = vadc_chans[prop->channel].prescale_index;
+	}
+
+	ret = of_property_read_u32(node, "qcom,hw-settle-time", &value);
+	if (!ret) {
+		ret = vadc_hw_settle_time_from_dt(value);
+		if (ret < 0) {
+			dev_dbg(dev, "%02x invalid hw-settle-time %d, us\n",
+				chan, value);
+			return ret;
+		}
+		prop->hw_settle_time = ret;
+	} else {
+		prop->hw_settle_time = VADC_DEF_HW_SETTLE_TIME;
+	}
+
+	ret = of_property_read_u32(node, "qcom,avg-samples", &value);
+	if (!ret) {
+		ret = vadc_avg_samples_from_dt(value);
+		if (ret < 0) {
+			dev_dbg(dev, "%02x invalid avg-samples %d\n",
+				chan, value);
+			return ret;
+		}
+		prop->avg_samples = ret;
+	} else {
+		prop->avg_samples = VADC_DEF_AVG_SAMPLES;
+	}
+
+	if (of_property_read_bool(node, "qcom,ratiometric"))
+		prop->calibration = VADC_CALIB_RATIOMETRIC;
+	else
+		prop->calibration = VADC_CALIB_ABSOLUTE;
+
+	dev_dbg(dev, "%02x name %s\n", chan, name);
+
+	return 0;
+}
+
+static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
+{
+	struct iio_chan_spec *iio_chan = vadc->iio_chans;
+	const struct vadc_channels *vadc_chan;
+	struct vadc_channel_prop prop;
+	struct device_node *child;
+	int ret, index = 0;
+
+	for_each_available_child_of_node(node, child) {
+		ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
+		if (ret)
+			return ret;
+
+		vadc->chan_props[index] = prop;
+
+		vadc_chan = &vadc_chans[prop.channel];
+
+		iio_chan->channel = prop.channel;
+		iio_chan->datasheet_name = vadc_chan->datasheet_name;
+		iio_chan->info_mask_separate = vadc_chan->info_mask;
+		iio_chan->type = vadc_chan->type;
+		iio_chan->indexed = 1;
+		iio_chan->scan_type.sign = 's';
+		iio_chan->scan_type.realbits = 15;
+		iio_chan->scan_type.storagebits = 16;
+		iio_chan->address = index++;
+
+		iio_chan++;
+	}
+
+	return 0;
+}
+
+static irqreturn_t vadc_isr(int irq, void *dev_id)
+{
+	struct vadc_priv *vadc = dev_id;
+
+	complete(&vadc->complete);
+
+	return IRQ_HANDLED;
+}
+
+static int vadc_check_revision(struct vadc_priv *vadc)
+{
+	u8 val;
+	int ret;
+
+	ret = vadc_read(vadc, VADC_PERPH_TYPE, &val);
+	if (ret)
+		return ret;
+
+	if (val < VADC_PERPH_TYPE_ADC) {
+		dev_dbg(vadc->dev, "%d is not ADC\n", val);
+		return -ENODEV;
+	}
+
+	ret = vadc_read(vadc, VADC_PERPH_SUBTYPE, &val);
+	if (ret)
+		return ret;
+
+	if (val < VADC_PERPH_SUBTYPE_VADC) {
+		dev_dbg(vadc->dev, "%d is not VADC\n", val);
+		return -ENODEV;
+	}
+
+	ret = vadc_read(vadc, VADC_REVISION2, &val);
+	if (ret)
+		return ret;
+
+	if (val < VADC_REVISION2_SUPPORTED_VADC) {
+		dev_dbg(vadc->dev, "revision %d not supported\n", val);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int vadc_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct device *dev = &pdev->dev;
+	struct iio_dev *indio_dev;
+	struct vadc_priv *vadc;
+	struct resource *res;
+	struct regmap *regmap;
+	int ret, irq_eoc;
+
+	regmap = dev_get_regmap(dev->parent, NULL);
+	if (!regmap)
+		return -ENODEV;
+
+	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
+	if (!res)
+		return -ENODEV;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*vadc));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	vadc = iio_priv(indio_dev);
+	vadc->regmap = regmap;
+	vadc->dev = dev;
+	vadc->base = res->start;
+	vadc->are_ref_measured = false;
+	init_completion(&vadc->complete);
+
+	ret = vadc_check_revision(vadc);
+	if (ret)
+		return ret;
+
+	vadc->nchannels = of_get_available_child_count(node);
+	if (!vadc->nchannels)
+		return -EINVAL;
+
+	vadc->iio_chans = devm_kcalloc(dev, vadc->nchannels,
+				       sizeof(*vadc->iio_chans), GFP_KERNEL);
+	if (!vadc->iio_chans)
+		return -ENOMEM;
+
+	vadc->chan_props = devm_kcalloc(dev, vadc->nchannels,
+					sizeof(*vadc->chan_props), GFP_KERNEL);
+	if (!vadc->chan_props)
+		return -ENOMEM;
+
+	ret = vadc_get_dt_data(vadc, node);
+	if (ret)
+		return ret;
+
+	irq_eoc = platform_get_irq(pdev, 0);
+	if (irq_eoc < 0) {
+		if (irq_eoc == -EPROBE_DEFER || irq_eoc == -EINVAL)
+			return irq_eoc;
+		vadc->poll_eoc = true;
+	}
+
+	if (!vadc->poll_eoc) {
+		ret = devm_request_irq(dev, irq_eoc, vadc_isr,
+				       IRQF_TRIGGER_RISING, "spmi-vadc", vadc);
+		if (!ret)
+			enable_irq_wake(irq_eoc);
+		else
+			return ret;
+	} else {
+		device_init_wakeup(vadc->dev, true);
+	}
+
+	ret = vadc_reset(vadc);
+	if (ret) {
+		dev_dbg(dev, "reset failed\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, vadc);
+
+	indio_dev->dev.parent = dev;
+	indio_dev->dev.of_node = node;
+	indio_dev->name = pdev->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &vadc_info;
+	indio_dev->channels = vadc->iio_chans;
+	indio_dev->num_channels = vadc->nchannels;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id vadc_match_table[] = {
+	{ .compatible = "qcom,spmi-vadc" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, vadc_match_table);
+
+static struct platform_driver vadc_driver = {
+	.driver = {
+		   .name = "spmi-vadc",
+		   .of_match_table = vadc_match_table,
+	},
+	.probe = vadc_probe,
+};
+module_platform_driver(vadc_driver);
+
+MODULE_ALIAS("platform:spmi-vadc");
+MODULE_DESCRIPTION("Qualcomm SPMI PMIC voltage ADC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>");
+MODULE_AUTHOR("Ivan T. Ivanov <iivanov@mm-sol.com>");
\ No newline at end of file
diff --git a/include/dt-bindings/iio/qcom,spmi-pmic-vadc.h b/include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
new file mode 100644
index 0000000..d543f24
--- /dev/null
+++ b/include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _DT_BINDINGS_QCOM_PMIC_ADC_H
+#define _DT_BINDINGS_QCOM_PMIC_ADC_H
+
+/* Voltage ADC channels */
+#define VADC_USBIN				0x00
+#define VADC_DCIN				0x01
+#define VADC_VCHG_SNS				0x02
+#define VADC_SPARE1_03				0x03
+#define VADC_USB_ID_MV				0x04
+#define VADC_VCOIN				0x05
+#define VADC_VBAT_SNS				0x06
+#define VADC_VSYS				0x07
+#define VADC_DIE_TEMP				0x08
+#define VADC_REF_625MV				0x09
+#define VADC_REF_1250MV				0x0a
+#define VADC_CHG_TEMP				0x0b
+#define VADC_SPARE1				0x0c
+#define VADC_SPARE2				0x0d
+#define VADC_GND_REF				0x0e
+#define VADC_VDD_VADC				0x0f
+
+#define VADC_P_MUX1_1_1				0x10
+#define VADC_P_MUX2_1_1				0x11
+#define VADC_P_MUX3_1_1				0x12
+#define VADC_P_MUX4_1_1				0x13
+#define VADC_P_MUX5_1_1				0x14
+#define VADC_P_MUX6_1_1				0x15
+#define VADC_P_MUX7_1_1				0x16
+#define VADC_P_MUX8_1_1				0x17
+#define VADC_P_MUX9_1_1				0x18
+#define VADC_P_MUX10_1_1			0x19
+#define VADC_P_MUX11_1_1			0x1a
+#define VADC_P_MUX12_1_1			0x1b
+#define VADC_P_MUX13_1_1			0x1c
+#define VADC_P_MUX14_1_1			0x1d
+#define VADC_P_MUX15_1_1			0x1e
+#define VADC_P_MUX16_1_1			0x1f
+
+#define VADC_P_MUX1_1_3				0x20
+#define VADC_P_MUX2_1_3				0x21
+#define VADC_P_MUX3_1_3				0x22
+#define VADC_P_MUX4_1_3				0x23
+#define VADC_P_MUX5_1_3				0x24
+#define VADC_P_MUX6_1_3				0x25
+#define VADC_P_MUX7_1_3				0x26
+#define VADC_P_MUX8_1_3				0x27
+#define VADC_P_MUX9_1_3				0x28
+#define VADC_P_MUX10_1_3			0x29
+#define VADC_P_MUX11_1_3			0x2a
+#define VADC_P_MUX12_1_3			0x2b
+#define VADC_P_MUX13_1_3			0x2c
+#define VADC_P_MUX14_1_3			0x2d
+#define VADC_P_MUX15_1_3			0x2e
+#define VADC_P_MUX16_1_3			0x2f
+
+#define VADC_LR_MUX1_BAT_THERM			0x30
+#define VADC_LR_MUX2_BAT_ID			0x31
+#define VADC_LR_MUX3_XO_THERM			0x32
+#define VADC_LR_MUX4_AMUX_THM1			0x33
+#define VADC_LR_MUX5_AMUX_THM2			0x34
+#define VADC_LR_MUX6_AMUX_THM3			0x35
+#define VADC_LR_MUX7_HW_ID			0x36
+#define VADC_LR_MUX8_AMUX_THM4			0x37
+#define VADC_LR_MUX9_AMUX_THM5			0x38
+#define VADC_LR_MUX10_USB_ID			0x39
+#define VADC_AMUX_PU1				0x3a
+#define VADC_AMUX_PU2				0x3b
+#define VADC_LR_MUX3_BUF_XO_THERM		0x3c
+
+#define VADC_LR_MUX1_PU1_BAT_THERM		0x70
+#define VADC_LR_MUX2_PU1_BAT_ID			0x71
+#define VADC_LR_MUX3_PU1_XO_THERM		0x72
+#define VADC_LR_MUX4_PU1_AMUX_THM1		0x73
+#define VADC_LR_MUX5_PU1_AMUX_THM2		0x74
+#define VADC_LR_MUX6_PU1_AMUX_THM3		0x75
+#define VADC_LR_MUX7_PU1_AMUX_HW_ID		0x76
+#define VADC_LR_MUX8_PU1_AMUX_THM4		0x77
+#define VADC_LR_MUX9_PU1_AMUX_THM5		0x78
+#define VADC_LR_MUX10_PU1_AMUX_USB_ID		0x79
+#define VADC_LR_MUX3_BUF_PU1_XO_THERM		0x7c
+
+#define VADC_LR_MUX1_PU2_BAT_THERM		0xb0
+#define VADC_LR_MUX2_PU2_BAT_ID			0xb1
+#define VADC_LR_MUX3_PU2_XO_THERM		0xb2
+#define VADC_LR_MUX4_PU2_AMUX_THM1		0xb3
+#define VADC_LR_MUX5_PU2_AMUX_THM2		0xb4
+#define VADC_LR_MUX6_PU2_AMUX_THM3		0xb5
+#define VADC_LR_MUX7_PU2_AMUX_HW_ID		0xb6
+#define VADC_LR_MUX8_PU2_AMUX_THM4		0xb7
+#define VADC_LR_MUX9_PU2_AMUX_THM5		0xb8
+#define VADC_LR_MUX10_PU2_AMUX_USB_ID		0xb9
+#define VADC_LR_MUX3_BUF_PU2_XO_THERM		0xbc
+
+#define VADC_LR_MUX1_PU1_PU2_BAT_THERM		0xf0
+#define VADC_LR_MUX2_PU1_PU2_BAT_ID		0xf1
+#define VADC_LR_MUX3_PU1_PU2_XO_THERM		0xf2
+#define VADC_LR_MUX4_PU1_PU2_AMUX_THM1		0xf3
+#define VADC_LR_MUX5_PU1_PU2_AMUX_THM2		0xf4
+#define VADC_LR_MUX6_PU1_PU2_AMUX_THM3		0xf5
+#define VADC_LR_MUX7_PU1_PU2_AMUX_HW_ID		0xf6
+#define VADC_LR_MUX8_PU1_PU2_AMUX_THM4		0xf7
+#define VADC_LR_MUX9_PU1_PU2_AMUX_THM5		0xf8
+#define VADC_LR_MUX10_PU1_PU2_AMUX_USB_ID	0xf9
+#define VADC_LR_MUX3_BUF_PU1_PU2_XO_THERM	0xfc
+
+#endif /* _DT_BINDINGS_QCOM_PMIC_ADC_H */
-- 
1.7.0.4

[PATCH v3 2/2] DT: iio: vadc: document dt binding

[Stanimir Varbanov]

Document DT binding for Qualcomm SPMI PMIC voltage ADC
driver.

Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
---
 .../devicetree/bindings/iio/adc/qcom,spmi-vadc.txt |  130 ++++++++++++++++++++
 1 files changed, 130 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt

diff --git a/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
new file mode 100644
index 0000000..fa30300
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
@@ -0,0 +1,130 @@
+Qualcomm's SPMI PMIC voltage ADC
+
+SPMI PMIC voltage ADC (VADC) provides interface to clients to read
+voltage. A 15 bit ADC is used for voltage measurements. There are multiple
+peripherals to the VADC and the scope of the driver is to provide interface
+for the USR peripheral of the VADC.
+
+VADC node:
+
+- compatible:
+    Usage: required
+    Value type: <string>
+    Definition: Should contain "qcom,spmi-vadc".
+
+- reg:
+    Usage: required
+    Value type: <u32>
+    Definition: Base address in the SPMI PMIC register map.
+
+- address-cells:
+    Usage: required
+    Value type: <u32>
+    Definition: Must be one.
+
+- size-cells:
+    Usage: required
+    Value type: <u32>
+    Definition: Must be zero.
+
+- interrupts:
+    Usage: optional
+    Value type: <prop-encoded-array>
+    Definition: End of conversion interrupt number. If this property does
+            not exist polling will be used instead.
+
+- interrupt-names:
+    Usage: optional
+    Value type: <string>
+    Definition: Should contain the interrupt name "eoc" (end of conversion).
+
+Channel node properties:
+
+- reg:
+    Usage: required
+    Value type: <u32>
+    Definition: AMUX channel number.
+            See include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
+
+- qcom,decimation:
+    Usage: optional
+    Value type: <u32>
+    Definition: Sampling rate to use for the individual channel measurement.
+            Quicker measurements can be made by reducing decimation ratio.
+            Valid values are 512, 1024, 2048, 4096.
+            If property is not found, default value of 512 will be used.
+
+- qcom,pre-scaling:
+    Usage: optional
+    Value type: <u32 array>
+    Definition: Used for scaling the channel input signal before the signal is
+            fed to VADC. The configuration for this node is to know the
+            pre-determined ratio and use it for post scaling. Select one from
+            the following options.
+            <1 1>, <1 3>, <1 4>, <1 6>, <1 20>, <1 8>, <10 81>, <1 10>
+            If property is not found default value depending of chip will be used.
+
+- qcom,ratiometric:
+    Usage: optional
+    Value type: <empty>
+    Definition: Channel calibration type. If this property is specified
+            VADC will use the VDD reference(1.8V) and GND for channel
+            calibration. If property is not found, channel will be
+            calibrated with 625mV and 1.25V reference channels.
+            Otherwise the absolute calibration will be used.
+
+- qcom,hw-settle-time:
+    Usage: optional
+    Value type: <u32>
+    Definition: Time between AMUX getting configured and the ADC starting
+            conversion. Delay = 100us * (value) for value < 11, and
+            2ms * (value - 10) otherwise.
+            Valid values are: 0, 100, 200, 300, 400, 500, 600, 700, 800,
+            900 us and 1, 2, 4, 6, 8, 10 ms
+            If property is not found, channel will use 0us.
+
+- qcom,avg-samples:
+    Usage: optional
+    Value type: <u32>
+    Definition: Number of samples to be used for measurement.
+            Fast averaging provides the option to obtain a single measurement
+            from the ADC that is an average of multiple samples. The value
+            selected is 2^(value).
+            Valid values are: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512
+            If property is not found, 1 sample will be used.
+
+NOTE: At least reference channel nodes are required. The reference channels
+      might be different depending on PMIC version.
+      Reference channels per type of calibration are:
+       - absolute
+         (VADC_REF_625MV or VADC_SPARE1) and VADC_REF_1250MV
+       - ratiomatric
+         VADC_GND_REF and VADC_VDD_VADC
+
+Example:
+	/* VADC node */
+	pmic_vadc: vadc@3100 {
+		compatible = "qcom,spmi-vadc";
+		reg = <0x3100 0x100>;
+		interrupts = <0x0 0x31 0x0 IRQ_TYPE_EDGE_RISING>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		#io-channel-cells = <1>;
+		io-channel-ranges;
+
+		/* Channel node */
+		usb_id_nopull {
+			reg = <VADC_LR_MUX10_USB_ID>;
+			qcom,decimation = <512>;
+			qcom,ratiometric;
+			qcom,hw-settle-time = <200>;
+			qcom,avg-samples = <1>;
+			qcom,pre-scaling = <1 3>;
+		};
+	};
+
+	/* IIO client node */
+	usb {
+		io-channels = <&pmic_vadc VADC_LR_MUX10_USB_ID>;
+		io-channel-names = "vadc";
+	};
-- 
1.7.0.4

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Ivan T. Ivanov]

Hi Stan, few comment bellow.

On Wed, 2014-09-24 at 15:56 +0300, Stanimir Varbanov wrote:
> The voltage ADC is peripheral of Qualcomm SPMI PMIC chips. It has
> 15bits resolution and register space inside PMIC accessible across
> SPMI bus.
> 
> The vadc driver registers itself through IIO interface.
> 
> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
> ---
>  drivers/iio/adc/Kconfig                       |   10 +
>  drivers/iio/adc/Makefile                      |    1 +
>  drivers/iio/adc/qcom-spmi-vadc.c              | 1029 +++++++++++++++++++++++++
>  include/dt-bindings/iio/qcom,spmi-pmic-vadc.h |  119 +++
>  4 files changed, 1159 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/iio/adc/qcom-spmi-vadc.c
>  create mode 100644 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 11b048a..ec48360 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -206,6 +206,16 @@ config NAU7802
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called nau7802.
>  
> +config QCOM_SPMI_VADC
> +	tristate "Qualcomm SPMI PMIC voltage ADC"
> +	depends on SPMI

+ select REGMAP_SPMI

<snip>

> +
> +static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
> +{
> +	return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);

just regmap_read() ?

> +}
> +

General comment, most of the dev_dbg looks like legitimate dev_err's to me.

Regards,
Ivan 

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Stanimir Varbanov]

Hi Ivan,

On 09/25/2014 03:47 PM, Ivan T. Ivanov wrote:
> 
> Hi Stan, few comment bellow.
> 
> On Wed, 2014-09-24 at 15:56 +0300, Stanimir Varbanov wrote:
>> The voltage ADC is peripheral of Qualcomm SPMI PMIC chips. It has
>> 15bits resolution and register space inside PMIC accessible across
>> SPMI bus.
>>
>> The vadc driver registers itself through IIO interface.
>>
>> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
>> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
>> ---
>>  drivers/iio/adc/Kconfig                       |   10 +
>>  drivers/iio/adc/Makefile                      |    1 +
>>  drivers/iio/adc/qcom-spmi-vadc.c              | 1029 +++++++++++++++++++++++++
>>  include/dt-bindings/iio/qcom,spmi-pmic-vadc.h |  119 +++
>>  4 files changed, 1159 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/iio/adc/qcom-spmi-vadc.c
>>  create mode 100644 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
>>
>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>> index 11b048a..ec48360 100644
>> --- a/drivers/iio/adc/Kconfig
>> +++ b/drivers/iio/adc/Kconfig
>> @@ -206,6 +206,16 @@ config NAU7802
>>  	  To compile this driver as a module, choose M here: the
>>  	  module will be called nau7802.
>>  
>> +config QCOM_SPMI_VADC
>> +	tristate "Qualcomm SPMI PMIC voltage ADC"
>> +	depends on SPMI
> 
> + select REGMAP_SPMI

I'd suggest MFD_SPMI_PMIC symbol of the parent driver instead? The
parent MFD PMIC driver already selects REGMAP_SPMI and depends on SPMI.

> 
> <snip>
> 
>> +
>> +static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
>> +{
>> +	return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);
> 
> just regmap_read() ?

No, regmap_read() expects unsigned int *val as an argument hence I will
need temporary variable. I had a comment to rework this on the first
version of the patchset.

> 
>> +}
>> +
> 
> General comment, most of the dev_dbg looks like legitimate dev_err's to me.

I've decided to not flood console with messages. If someone wants to
debug why the driver doesn't probed he can define DEBUG.

-- 
regards,
Stan

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Ivan T. Ivanov]

On Thu, 2014-09-25 at 18:30 +0300, Stanimir Varbanov wrote:
> Hi Ivan,
> 
> On 09/25/2014 03:47 PM, Ivan T. Ivanov wrote:
> > 
> > Hi Stan, few comment bellow.
> > 
> > On Wed, 2014-09-24 at 15:56 +0300, Stanimir Varbanov wrote:
> >> The voltage ADC is peripheral of Qualcomm SPMI PMIC chips. It has
> >> 15bits resolution and register space inside PMIC accessible across
> >> SPMI bus.
> >>
> >> The vadc driver registers itself through IIO interface.
> >>
> >> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
> >> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
> >> ---
> >>  drivers/iio/adc/Kconfig                       |   10 +
> >>  drivers/iio/adc/Makefile                      |    1 +
> >>  drivers/iio/adc/qcom-spmi-vadc.c              | 1029 +++++++++++++++++++++++++
> >>  include/dt-bindings/iio/qcom,spmi-pmic-vadc.h |  119 +++
> >>  4 files changed, 1159 insertions(+), 0 deletions(-)
> >>  create mode 100644 drivers/iio/adc/qcom-spmi-vadc.c
> >>  create mode 100644 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
> >>
> >> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> >> index 11b048a..ec48360 100644
> >> --- a/drivers/iio/adc/Kconfig
> >> +++ b/drivers/iio/adc/Kconfig
> >> @@ -206,6 +206,16 @@ config NAU7802
> >>  	  To compile this driver as a module, choose M here: the
> >>  	  module will be called nau7802.
> >>  
> >> +config QCOM_SPMI_VADC
> >> +	tristate "Qualcomm SPMI PMIC voltage ADC"
> >> +	depends on SPMI
> > 
> > + select REGMAP_SPMI
> 
> I'd suggest MFD_SPMI_PMIC symbol of the parent driver instead? The
> parent MFD PMIC driver already selects REGMAP_SPMI and depends on SPMI.


+1 for depends on MFD_SPMI_PMIC.

> 
> > 
> > <snip>
> > 
> >> +
> >> +static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
> >> +{
> >> +	return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);
> > 
> > just regmap_read() ?
> 
> No, regmap_read() expects unsigned int *val as an argument hence I will
> need temporary variable. I had a comment to rework this on the first
> version of the patchset.

Oops, So I should expect the same comment on my IADC driver :-)

> 
> > 
> >> +}
> >> +
> > 
> > General comment, most of the dev_dbg looks like legitimate dev_err's to me.
> 
> I've decided to not flood console with messages. If someone wants to
> debug why the driver doesn't probed he can define DEBUG.

Ok, is up to you.

Regards,
Ivan

Re: [PATCH v3 2/2] DT: iio: vadc: document dt binding

[Jonathan Cameron]

On 24/09/14 13:56, Stanimir Varbanov wrote:
> Document DT binding for Qualcomm SPMI PMIC voltage ADC
> driver.
> 
> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Ideally I'd like a device tree maintainer to take a look at this
as it's non trivial.  Right now we have just missed this cycle anyway so there
is now plenty of time.

Jonathan
> ---
>  .../devicetree/bindings/iio/adc/qcom,spmi-vadc.txt |  130 ++++++++++++++++++++
>  1 files changed, 130 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> new file mode 100644
> index 0000000..fa30300
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> @@ -0,0 +1,130 @@
> +Qualcomm's SPMI PMIC voltage ADC
> +
> +SPMI PMIC voltage ADC (VADC) provides interface to clients to read
> +voltage. A 15 bit ADC is used for voltage measurements. There are multiple
> +peripherals to the VADC and the scope of the driver is to provide interface
> +for the USR peripheral of the VADC.
> +
> +VADC node:
> +
> +- compatible:
> +    Usage: required
> +    Value type: <string>
> +    Definition: Should contain "qcom,spmi-vadc".
> +
> +- reg:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: Base address in the SPMI PMIC register map.
> +
> +- address-cells:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: Must be one.
> +
> +- size-cells:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: Must be zero.
> +
> +- interrupts:
> +    Usage: optional
> +    Value type: <prop-encoded-array>
> +    Definition: End of conversion interrupt number. If this property does
> +            not exist polling will be used instead.
> +
> +- interrupt-names:
> +    Usage: optional
> +    Value type: <string>
> +    Definition: Should contain the interrupt name "eoc" (end of conversion).
> +
> +Channel node properties:
> +
> +- reg:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: AMUX channel number.
> +            See include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
> +
> +- qcom,decimation:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Sampling rate to use for the individual channel measurement.
> +            Quicker measurements can be made by reducing decimation ratio.
> +            Valid values are 512, 1024, 2048, 4096.
> +            If property is not found, default value of 512 will be used.
> +
> +- qcom,pre-scaling:
> +    Usage: optional
> +    Value type: <u32 array>
> +    Definition: Used for scaling the channel input signal before the signal is
> +            fed to VADC. The configuration for this node is to know the
> +            pre-determined ratio and use it for post scaling. Select one from
> +            the following options.
> +            <1 1>, <1 3>, <1 4>, <1 6>, <1 20>, <1 8>, <10 81>, <1 10>
> +            If property is not found default value depending of chip will be used.
> +
> +- qcom,ratiometric:
> +    Usage: optional
> +    Value type: <empty>
> +    Definition: Channel calibration type. If this property is specified
> +            VADC will use the VDD reference(1.8V) and GND for channel
> +            calibration. If property is not found, channel will be
> +            calibrated with 625mV and 1.25V reference channels.
> +            Otherwise the absolute calibration will be used.
> +
> +- qcom,hw-settle-time:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Time between AMUX getting configured and the ADC starting
> +            conversion. Delay = 100us * (value) for value < 11, and
> +            2ms * (value - 10) otherwise.
> +            Valid values are: 0, 100, 200, 300, 400, 500, 600, 700, 800,
> +            900 us and 1, 2, 4, 6, 8, 10 ms
> +            If property is not found, channel will use 0us.
> +
> +- qcom,avg-samples:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Number of samples to be used for measurement.
> +            Fast averaging provides the option to obtain a single measurement
> +            from the ADC that is an average of multiple samples. The value
> +            selected is 2^(value).
> +            Valid values are: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512
> +            If property is not found, 1 sample will be used.
> +
> +NOTE: At least reference channel nodes are required. The reference channels
> +      might be different depending on PMIC version.
> +      Reference channels per type of calibration are:
> +       - absolute
> +         (VADC_REF_625MV or VADC_SPARE1) and VADC_REF_1250MV
> +       - ratiomatric
> +         VADC_GND_REF and VADC_VDD_VADC
> +
> +Example:
> +	/* VADC node */
> +	pmic_vadc: vadc@3100 {
> +		compatible = "qcom,spmi-vadc";
> +		reg = <0x3100 0x100>;
> +		interrupts = <0x0 0x31 0x0 IRQ_TYPE_EDGE_RISING>;
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		#io-channel-cells = <1>;
> +		io-channel-ranges;
> +
> +		/* Channel node */
> +		usb_id_nopull {
> +			reg = <VADC_LR_MUX10_USB_ID>;
> +			qcom,decimation = <512>;
> +			qcom,ratiometric;
> +			qcom,hw-settle-time = <200>;
> +			qcom,avg-samples = <1>;
> +			qcom,pre-scaling = <1 3>;
> +		};
> +	};
> +
> +	/* IIO client node */
> +	usb {
> +		io-channels = <&pmic_vadc VADC_LR_MUX10_USB_ID>;
> +		io-channel-names = "vadc";
> +	};
> 

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Ivan T. Ivanov]

Hi Stan,

On 09/24/2014 03:56 PM, Stanimir Varbanov wrote:

<snip>

> +static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
> +{
> +	struct iio_chan_spec *iio_chan = vadc->iio_chans;
> +	const struct vadc_channels *vadc_chan;
> +	struct vadc_channel_prop prop;
> +	struct device_node *child;
> +	int ret, index = 0;
> +
> +	for_each_available_child_of_node(node, child) {
> +		ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
> +		if (ret)
> +			return ret;
> +
> +		vadc->chan_props[index] = prop;
> +
> +		vadc_chan = &vadc_chans[prop.channel];
> +
> +		iio_chan->channel = prop.channel;
> +		iio_chan->datasheet_name = vadc_chan->datasheet_name;
> +		iio_chan->info_mask_separate = vadc_chan->info_mask;
> +		iio_chan->type = vadc_chan->type;
> +		iio_chan->indexed = 1;
> +		iio_chan->scan_type.sign = 's';
> +		iio_chan->scan_type.realbits = 15;
> +		iio_chan->scan_type.storagebits = 16;
> +		iio_chan->address = index++;
> +
> +		iio_chan++;
> +	}
> +
> +	return 0;
> +}
> +

<snip>

> +static int vadc_probe(struct platform_device *pdev)
> +{

<snip>

> +
> +	indio_dev->dev.parent = dev;
> +	indio_dev->dev.of_node = node;
> +	indio_dev->name = pdev->name;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &vadc_info;
> +	indio_dev->channels = vadc->iio_chans;
> +	indio_dev->num_channels = vadc->nchannels;

This will not work as we thought. Registration will be fine and entries
in sysfs are created as expected, but this is breaking numbering scheme
for client drivers. For us the problem is that iio framework expect channels
numbering to be linear and channel number should not be greater than
channel count. For example even if die temperature channel is always 8, if
I describe only 5 channels in DTS files (4 for reference points measurement)
and 1 for die temperature, clients could not get OF reference to 
temperature
channel using io-channels = <&pm8941_vadc 8>;

Jonathan, please, could you advise us.

Regards,
Ivan

> +
> +	return devm_iio_device_register(dev, indio_dev);
> +}
> +
>

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Ivan T. Ivanov]

+iio maintainers

On Thu, 2014-10-02 at 12:29 +0300, Ivan T. Ivanov wrote:
> Hi Stan,
> 
> On 09/24/2014 03:56 PM, Stanimir Varbanov wrote:
> 
> <snip>
> 
> > +static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
> > +{
> > +	struct iio_chan_spec *iio_chan = vadc->iio_chans;
> > +	const struct vadc_channels *vadc_chan;
> > +	struct vadc_channel_prop prop;
> > +	struct device_node *child;
> > +	int ret, index = 0;
> > +
> > +	for_each_available_child_of_node(node, child) {
> > +		ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
> > +		if (ret)
> > +			return ret;
> > +
> > +		vadc->chan_props[index] = prop;
> > +
> > +		vadc_chan = &vadc_chans[prop.channel];
> > +
> > +		iio_chan->channel = prop.channel;
> > +		iio_chan->datasheet_name = vadc_chan->datasheet_name;
> > +		iio_chan->info_mask_separate = vadc_chan->info_mask;
> > +		iio_chan->type = vadc_chan->type;
> > +		iio_chan->indexed = 1;
> > +		iio_chan->scan_type.sign = 's';
> > +		iio_chan->scan_type.realbits = 15;
> > +		iio_chan->scan_type.storagebits = 16;
> > +		iio_chan->address = index++;
> > +
> > +		iio_chan++;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> 
> <snip>
> 
> > +static int vadc_probe(struct platform_device *pdev)
> > +{
> 
> <snip>
> 
> > +
> > +	indio_dev->dev.parent = dev;
> > +	indio_dev->dev.of_node = node;
> > +	indio_dev->name = pdev->name;
> > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > +	indio_dev->info = &vadc_info;
> > +	indio_dev->channels = vadc->iio_chans;
> > +	indio_dev->num_channels = vadc->nchannels;
> 
> This will not work as we thought. Registration will be fine and entries
> in sysfs are created as expected, but this is breaking numbering scheme
> for client drivers. For us the problem is that iio framework expect channels
> numbering to be linear and channel number should not be greater than
> channel count. For example even if die temperature channel is always 8, if
> I describe only 5 channels in DTS files (4 for reference points measurement)
> and 1 for die temperature, clients could not get OF reference to 
> temperature
> channel using io-channels = <&pm8941_vadc 8>;
> 
> Jonathan, please, could you advise us.
> 
> Regards,
> Ivan
> 
> > +
> > +	return devm_iio_device_register(dev, indio_dev);
> > +}
> > +
> >
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Jonathan Cameron]

On 02/10/14 13:08, Ivan T. Ivanov wrote:
> +iio maintainers
> 
> On Thu, 2014-10-02 at 12:29 +0300, Ivan T. Ivanov wrote:
>> Hi Stan,
>>
>> On 09/24/2014 03:56 PM, Stanimir Varbanov wrote:
>>
>> <snip>
>>
>>> +static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
>>> +{
>>> +	struct iio_chan_spec *iio_chan = vadc->iio_chans;
>>> +	const struct vadc_channels *vadc_chan;
>>> +	struct vadc_channel_prop prop;
>>> +	struct device_node *child;
>>> +	int ret, index = 0;
>>> +
>>> +	for_each_available_child_of_node(node, child) {
>>> +		ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
>>> +		if (ret)
>>> +			return ret;
>>> +
>>> +		vadc->chan_props[index] = prop;
>>> +
>>> +		vadc_chan = &vadc_chans[prop.channel];
>>> +
>>> +		iio_chan->channel = prop.channel;
>>> +		iio_chan->datasheet_name = vadc_chan->datasheet_name;
>>> +		iio_chan->info_mask_separate = vadc_chan->info_mask;
>>> +		iio_chan->type = vadc_chan->type;
>>> +		iio_chan->indexed = 1;
>>> +		iio_chan->scan_type.sign = 's';
>>> +		iio_chan->scan_type.realbits = 15;
>>> +		iio_chan->scan_type.storagebits = 16;
>>> +		iio_chan->address = index++;
>>> +
>>> +		iio_chan++;
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>
>> <snip>
>>
>>> +static int vadc_probe(struct platform_device *pdev)
>>> +{
>>
>> <snip>
>>
>>> +
>>> +	indio_dev->dev.parent = dev;
>>> +	indio_dev->dev.of_node = node;
>>> +	indio_dev->name = pdev->name;
>>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>>> +	indio_dev->info = &vadc_info;
>>> +	indio_dev->channels = vadc->iio_chans;
>>> +	indio_dev->num_channels = vadc->nchannels;
>>
>> This will not work as we thought. Registration will be fine and entries
>> in sysfs are created as expected, but this is breaking numbering scheme
>> for client drivers. For us the problem is that iio framework expect channels
>> numbering to be linear and channel number should not be greater than
>> channel count. For example even if die temperature channel is always 8, if
>> I describe only 5 channels in DTS files (4 for reference points measurement)
>> and 1 for die temperature, clients could not get OF reference to 
>> temperature
>> channel using io-channels = <&pm8941_vadc 8>;
>>
>> Jonathan, please, could you advise us.
I'd like to let the solution you proposed sit on the list a little longer.
It seems fairly sensible, but lets see what others suggest.

Jonathan
>>
>> Regards,
>> Ivan
>>
>>> +
>>> +	return devm_iio_device_register(dev, indio_dev);
>>> +}
>>> +
>>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Ivan T. Ivanov]

On Sat, 2014-10-04 at 12:51 +0100, Jonathan Cameron wrote:
> On 02/10/14 13:08, Ivan T. Ivanov wrote:
> > +iio maintainers
> > 
> > On Thu, 2014-10-02 at 12:29 +0300, Ivan T. Ivanov wrote:
> >> Hi Stan,
> >>
> >> On 09/24/2014 03:56 PM, Stanimir Varbanov wrote:
> >>
> >> <snip>
> >>
> >>> +static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
> >>> +{
> >>> +	struct iio_chan_spec *iio_chan = vadc->iio_chans;
> >>> +	const struct vadc_channels *vadc_chan;
> >>> +	struct vadc_channel_prop prop;
> >>> +	struct device_node *child;
> >>> +	int ret, index = 0;
> >>> +
> >>> +	for_each_available_child_of_node(node, child) {
> >>> +		ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
> >>> +		if (ret)
> >>> +			return ret;
> >>> +
> >>> +		vadc->chan_props[index] = prop;
> >>> +
> >>> +		vadc_chan = &vadc_chans[prop.channel];
> >>> +
> >>> +		iio_chan->channel = prop.channel;
> >>> +		iio_chan->datasheet_name = vadc_chan->datasheet_name;
> >>> +		iio_chan->info_mask_separate = vadc_chan->info_mask;
> >>> +		iio_chan->type = vadc_chan->type;
> >>> +		iio_chan->indexed = 1;
> >>> +		iio_chan->scan_type.sign = 's';
> >>> +		iio_chan->scan_type.realbits = 15;
> >>> +		iio_chan->scan_type.storagebits = 16;
> >>> +		iio_chan->address = index++;
> >>> +
> >>> +		iio_chan++;
> >>> +	}
> >>> +
> >>> +	return 0;
> >>> +}
> >>> +
> >>
> >> <snip>
> >>
> >>> +static int vadc_probe(struct platform_device *pdev)
> >>> +{
> >>
> >> <snip>
> >>
> >>> +
> >>> +	indio_dev->dev.parent = dev;
> >>> +	indio_dev->dev.of_node = node;
> >>> +	indio_dev->name = pdev->name;
> >>> +	indio_dev->modes = INDIO_DIRECT_MODE;
> >>> +	indio_dev->info = &vadc_info;
> >>> +	indio_dev->channels = vadc->iio_chans;
> >>> +	indio_dev->num_channels = vadc->nchannels;
> >>
> >> This will not work as we thought. Registration will be fine and entries
> >> in sysfs are created as expected, but this is breaking numbering scheme
> >> for client drivers. For us the problem is that iio framework expect channels
> >> numbering to be linear and channel number should not be greater than
> >> channel count. For example even if die temperature channel is always 8, if
> >> I describe only 5 channels in DTS files (4 for reference points measurement)
> >> and 1 for die temperature, clients could not get OF reference to 
> >> temperature
> >> channel using io-channels = <&pm8941_vadc 8>;
> >>
> >> Jonathan, please, could you advise us.
> I'd like to let the solution you proposed sit on the list a little longer.
> It seems fairly sensible, but lets see what others suggest.

Sure. 

Thank you.
Ivan

Re: [PATCH v3 2/2] DT: iio: vadc: document dt binding

[Hartmut Knaack]

Hi,
two small issues inline.
Stanimir Varbanov schrieb am 24.09.2014 14:56:
> Document DT binding for Qualcomm SPMI PMIC voltage ADC
> driver.
> 
> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
> ---
>  .../devicetree/bindings/iio/adc/qcom,spmi-vadc.txt |  130 ++++++++++++++++++++
>  1 files changed, 130 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> new file mode 100644
> index 0000000..fa30300
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> @@ -0,0 +1,130 @@
> +Qualcomm's SPMI PMIC voltage ADC
> +
> +SPMI PMIC voltage ADC (VADC) provides interface to clients to read
> +voltage. A 15 bit ADC is used for voltage measurements. There are multiple
> +peripherals to the VADC and the scope of the driver is to provide interface
> +for the USR peripheral of the VADC.
> +
> +VADC node:
> +
> +- compatible:
> +    Usage: required
> +    Value type: <string>
> +    Definition: Should contain "qcom,spmi-vadc".
> +
> +- reg:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: Base address in the SPMI PMIC register map.
> +
> +- address-cells:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: Must be one.
> +
> +- size-cells:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: Must be zero.
> +
> +- interrupts:
> +    Usage: optional
> +    Value type: <prop-encoded-array>
> +    Definition: End of conversion interrupt number. If this property does
> +            not exist polling will be used instead.
> +
> +- interrupt-names:
> +    Usage: optional
> +    Value type: <string>
> +    Definition: Should contain the interrupt name "eoc" (end of conversion).
> +
> +Channel node properties:
> +
> +- reg:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: AMUX channel number.
> +            See include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
> +
> +- qcom,decimation:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Sampling rate to use for the individual channel measurement.
> +            Quicker measurements can be made by reducing decimation ratio.
> +            Valid values are 512, 1024, 2048, 4096.
> +            If property is not found, default value of 512 will be used.
> +
> +- qcom,pre-scaling:
> +    Usage: optional
> +    Value type: <u32 array>
> +    Definition: Used for scaling the channel input signal before the signal is
> +            fed to VADC. The configuration for this node is to know the
> +            pre-determined ratio and use it for post scaling. Select one from
> +            the following options.
> +            <1 1>, <1 3>, <1 4>, <1 6>, <1 20>, <1 8>, <10 81>, <1 10>
> +            If property is not found default value depending of chip will be used.
> +
> +- qcom,ratiometric:
> +    Usage: optional
> +    Value type: <empty>
> +    Definition: Channel calibration type. If this property is specified
> +            VADC will use the VDD reference(1.8V) and GND for channel
Missing whitespace before opening parenthesis.
> +            calibration. If property is not found, channel will be
> +            calibrated with 625mV and 1.25V reference channels.
There is a slight majority in using V instead of mv (2 : 1), so why not express everything in V?
> +            Otherwise the absolute calibration will be used.
> +
> +- qcom,hw-settle-time:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Time between AMUX getting configured and the ADC starting
> +            conversion. Delay = 100us * (value) for value < 11, and
> +            2ms * (value - 10) otherwise.
> +            Valid values are: 0, 100, 200, 300, 400, 500, 600, 700, 800,
> +            900 us and 1, 2, 4, 6, 8, 10 ms
> +            If property is not found, channel will use 0us.
> +
> +- qcom,avg-samples:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Number of samples to be used for measurement.
> +            Fast averaging provides the option to obtain a single measurement
> +            from the ADC that is an average of multiple samples. The value
> +            selected is 2^(value).
> +            Valid values are: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512
> +            If property is not found, 1 sample will be used.
> +
> +NOTE: At least reference channel nodes are required. The reference channels
> +      might be different depending on PMIC version.
> +      Reference channels per type of calibration are:
> +       - absolute
> +         (VADC_REF_625MV or VADC_SPARE1) and VADC_REF_1250MV
> +       - ratiomatric
> +         VADC_GND_REF and VADC_VDD_VADC
> +
> +Example:
> +	/* VADC node */
> +	pmic_vadc: vadc@3100 {
> +		compatible = "qcom,spmi-vadc";
> +		reg = <0x3100 0x100>;
> +		interrupts = <0x0 0x31 0x0 IRQ_TYPE_EDGE_RISING>;
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		#io-channel-cells = <1>;
> +		io-channel-ranges;
> +
> +		/* Channel node */
> +		usb_id_nopull {
> +			reg = <VADC_LR_MUX10_USB_ID>;
> +			qcom,decimation = <512>;
> +			qcom,ratiometric;
> +			qcom,hw-settle-time = <200>;
> +			qcom,avg-samples = <1>;
> +			qcom,pre-scaling = <1 3>;
> +		};
> +	};
> +
> +	/* IIO client node */
> +	usb {
> +		io-channels = <&pmic_vadc VADC_LR_MUX10_USB_ID>;
> +		io-channel-names = "vadc";
> +	};
> 

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Hartmut Knaack]

Stanimir Varbanov schrieb am 24.09.2014 14:56:
> The voltage ADC is peripheral of Qualcomm SPMI PMIC chips. It has
> 15bits resolution and register space inside PMIC accessible across
> SPMI bus.
> 
> The vadc driver registers itself through IIO interface.
Quite a lot of changes. Please see my comments inline.
> 
> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
> ---
>  drivers/iio/adc/Kconfig                       |   10 +
>  drivers/iio/adc/Makefile                      |    1 +
>  drivers/iio/adc/qcom-spmi-vadc.c              | 1029 +++++++++++++++++++++++++
>  include/dt-bindings/iio/qcom,spmi-pmic-vadc.h |  119 +++
>  4 files changed, 1159 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/iio/adc/qcom-spmi-vadc.c
>  create mode 100644 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 11b048a..ec48360 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -206,6 +206,16 @@ config NAU7802
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called nau7802.
>  
> +config QCOM_SPMI_VADC
> +	tristate "Qualcomm SPMI PMIC voltage ADC"
> +	depends on SPMI
> +	help
> +	  Say yes here if you want support for the Qualcomm SPMI PMIC voltage ADC.
> +
> +	  The driver supports reading the HKADC, XOADC through the ADC AMUX arbiter.
> +	  The driver supports reading the ADC through the AMUX channels for
> +	  external pull-ups simultaneously.
> +
>  config TI_ADC081C
>  	tristate "Texas Instruments ADC081C021/027"
>  	depends on I2C
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index ad81b51..d5d18f4 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -22,6 +22,7 @@ obj-$(CONFIG_MCP320X) += mcp320x.o
>  obj-$(CONFIG_MCP3422) += mcp3422.o
>  obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
>  obj-$(CONFIG_NAU7802) += nau7802.o
> +obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
>  obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
>  obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
>  obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
> diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c
> new file mode 100644
> index 0000000..9e3e022
> --- /dev/null
> +++ b/drivers/iio/adc/qcom-spmi-vadc.c
> @@ -0,0 +1,1029 @@
> +/*
> + * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/completion.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/iio/iio.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/log2.h>
> +
> +#include <dt-bindings/iio/qcom,spmi-pmic-vadc.h>
> +
> +/* VADC register and bit definitions */
> +#define VADC_REVISION2				0x1
> +#define VADC_REVISION2_SUPPORTED_VADC		1
> +
> +#define VADC_PERPH_TYPE				0x4
> +#define VADC_PERPH_TYPE_ADC			8
> +
> +#define VADC_PERPH_SUBTYPE			0x5
> +#define VADC_PERPH_SUBTYPE_VADC			1
> +
> +#define VADC_STATUS1				0x8
> +#define VADC_STATUS1_OP_MODE			4
> +#define VADC_STATUS1_REQ_STS			BIT(1)
> +#define VADC_STATUS1_EOC			BIT(0)
> +#define VADC_STATUS1_REQ_STS_EOC_MASK		0x3
> +
> +#define VADC_MODE_CTL				0x40
> +#define VADC_OP_MODE_SHIFT			3
> +#define VADC_OP_MODE_NORMAL			0
> +#define VADC_AMUX_TRIM_EN			BIT(1)
> +#define VADC_ADC_TRIM_EN			BIT(0)
> +
> +#define VADC_EN_CTL1				0x46
> +#define VADC_EN_CTL1_SET			BIT(7)
> +
> +#define VADC_ADC_CH_SEL_CTL			0x48
> +
> +#define VADC_ADC_DIG_PARAM			0x50
> +#define VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT	2
> +
> +#define VADC_HW_SETTLE_DELAY			0x51
> +
> +#define VADC_CONV_REQ				0x52
> +#define VADC_CONV_REQ_SET			BIT(7)
> +
> +#define VADC_FAST_AVG_CTL			0x5a
> +#define VADC_FAST_AVG_EN			0x5b
> +#define VADC_FAST_AVG_EN_SET			BIT(7)
> +
> +#define VADC_ACCESS				0xd0
> +#define VADC_ACCESS_DATA			0xa5
> +
> +#define VADC_PERH_RESET_CTL3			0xda
> +#define VADC_FOLLOW_WARM_RB			BIT(2)
> +
> +#define VADC_DATA0				0x60
> +#define VADC_DATA1				0x61
> +
> +#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 reference channels.
> + * VADC_CALIB_RATIOMETRIC: uses the reference Voltage/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.
> + * @vref: A/D word of the voltage reference used for the channel.
> + * @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 vref;
> +	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.
> + * @calibration: calibration type.
> + * @decimation: sampling rate supported for the channel.
> + * @prescale: channel scaling performed on the input signal.
> + * @hw_settle_time: the time between AMUX being configured and the
> + *	start of conversion.
> + * @avg_samples: ability to provide single result from the ADC
> + *	that is an average of multiple measurements.
> + */
> +struct vadc_channel_prop {
> +	unsigned int channel;
> +	enum vadc_calibration calibration;
> +	unsigned int decimation;
> +	unsigned int prescale;
> +	unsigned int hw_settle_time;
> +	unsigned int avg_samples;
> +};
> +
> +/**
> + * struct vadc_priv - VADC private structure.
> + * @regmap: pointer to struct regmap.
> + * @dev: pointer to struct device.
> + * @base: base address for the ADC peripheral.
> + * @nchannels: number of VADC channels.
> + * @chan_props: array of VADC channel properties.
> + * @iio_chans: array of IIO channels specification.
> + * @are_ref_measured: are reference points measured.
> + * @poll_eoc: use polling instead of interrupt.
> + * @complete: VADC result notification after interrupt is received.
> + * @graph: store parameters for calibration.
> + */
> +struct vadc_priv {
> +	struct regmap *regmap;
> +	struct device *dev;
> +	u16 base;
> +	unsigned int nchannels;
> +	struct vadc_channel_prop *chan_props;
> +	struct iio_chan_spec *iio_chans;
> +	bool are_ref_measured;
> +	bool poll_eoc;
> +	struct completion complete;
> +	struct vadc_linear_graph graph[2];
> +};
> +
> +static const struct vadc_prescale_ratio vadc_prescale_ratios[] = {
> +	{.num =  1, .den =  1},
> +	{.num =  1, .den =  3},
> +	{.num =  1, .den =  4},
> +	{.num =  1, .den =  6},
> +	{.num =  1, .den = 20},
> +	{.num =  1, .den =  8},
> +	{.num = 10, .den = 81},
> +	{.num =  1, .den = 10}
> +};
> +
> +static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
> +{
> +	return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);
> +}
> +
> +static int vadc_write(struct vadc_priv *vadc, u16 offset, u8 data)
> +{
> +	return regmap_write(vadc->regmap, vadc->base + offset, data);
> +}
> +
> +static int vadc_reset(struct vadc_priv *vadc)
> +{
> +	u8 data;
> +	int ret;
> +
> +	ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
> +	if (ret)
> +		return ret;
> +
> +	ret = vadc_read(vadc, VADC_PERH_RESET_CTL3, &data);
> +	if (ret)
> +		return ret;
> +
> +	ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
> +	if (ret)
> +		return ret;
> +
> +	data |= VADC_FOLLOW_WARM_RB;
> +
> +	return vadc_write(vadc, VADC_PERH_RESET_CTL3, data);
> +}
> +
> +static int vadc_enable(struct vadc_priv *vadc, bool state)
> +{
> +	return vadc_write(vadc, VADC_EN_CTL1, state ? VADC_EN_CTL1_SET : 0);
> +}
> +
> +#ifdef DEBUG
> +static void vadc_show_status(struct vadc_priv *vadc)
> +{
You could also move the #ifdef in here...
> +	u8 mode, sta1, chan, dig, en, req;
> +	int ret;
> +
> +	ret = vadc_read(vadc, VADC_MODE_CTL, &mode);
> +	if (ret)
> +		return;
> +
> +	ret = vadc_read(vadc, VADC_ADC_DIG_PARAM, &dig);
> +	if (ret)
> +		return;
> +
> +	ret = vadc_read(vadc, VADC_ADC_CH_SEL_CTL, &chan);
> +	if (ret)
> +		return;
> +
> +	ret = vadc_read(vadc, VADC_CONV_REQ, &req);
> +	if (ret)
> +		return;
> +
> +	ret = vadc_read(vadc, VADC_STATUS1, &sta1);
> +	if (ret)
> +		return;
> +
> +	ret = vadc_read(vadc, VADC_EN_CTL1, &en);
> +	if (ret)
> +		return;
> +
> +	dev_dbg(vadc->dev,
> +		"mode:%02x en:%02x chan:%02x dig:%02x req:%02x sta1:%02x\n",
> +		mode, en, chan, dig, req, sta1);
...and the #endif here. Saves 2 lines of code ;-)
> +}
> +#else
> +static void vadc_show_status(struct vadc_priv *vadc) {}
> +#endif
> +
> +static int vadc_configure(struct vadc_priv *vadc,
> +			  struct vadc_channel_prop *prop)
> +{
> +	u8 decimation, mode_ctrl;
> +	int ret;
> +
> +	/* Mode selection */
> +	mode_ctrl = (VADC_OP_MODE_NORMAL << VADC_OP_MODE_SHIFT) |
> +		     VADC_ADC_TRIM_EN | VADC_AMUX_TRIM_EN;
> +	ret = vadc_write(vadc, VADC_MODE_CTL, mode_ctrl);
> +	if (ret)
> +		return ret;
> +
> +	/* Channel selection */
> +	ret = vadc_write(vadc, VADC_ADC_CH_SEL_CTL, prop->channel);
> +	if (ret)
> +		return ret;
> +
> +	/* Digital parameter setup */
> +	decimation = prop->decimation << VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT;
> +	ret = vadc_write(vadc, VADC_ADC_DIG_PARAM, decimation);
> +	if (ret)
> +		return ret;
> +
> +	/* HW settle time delay */
> +	ret = vadc_write(vadc, VADC_HW_SETTLE_DELAY, prop->hw_settle_time);
> +	if (ret)
> +		return ret;
> +
> +	ret = vadc_write(vadc, VADC_FAST_AVG_CTL, prop->avg_samples);
> +	if (ret)
> +		return ret;
> +
> +	if (prop->avg_samples)
> +		ret = vadc_write(vadc, VADC_FAST_AVG_EN, VADC_FAST_AVG_EN_SET);
> +	else
> +		ret = vadc_write(vadc, VADC_FAST_AVG_EN, 0);
> +
> +	return ret;
> +}
> +
> +static int vadc_poll_wait_eoc(struct vadc_priv *vadc, unsigned int interval_us)
> +{
> +	unsigned int count, retry;
> +	u8 sta1;
> +	int ret;
> +
> +	retry = interval_us / VADC_CONV_TIME_MIN_US;
> +
> +	for (count = 0; count < retry; count++) {
> +		ret = vadc_read(vadc, VADC_STATUS1, &sta1);
> +		if (ret)
> +			return ret;
> +
> +		sta1 &= VADC_STATUS1_REQ_STS_EOC_MASK;
> +		if (sta1 == VADC_STATUS1_EOC)
> +			return 0;
> +
> +		usleep_range(VADC_CONV_TIME_MIN_US, VADC_CONV_TIME_MAX_US);
> +	}
> +
> +	vadc_show_status(vadc);
> +
> +	return -ETIMEDOUT;
> +}
> +
> +static int vadc_read_result(struct vadc_priv *vadc, s32 *data)
> +{
> +	u8 lsb, msb;
> +	int ret;
> +
> +	ret = vadc_read(vadc, VADC_DATA0, &lsb);
> +	if (ret)
> +		return ret;
> +
> +	ret = vadc_read(vadc, VADC_DATA1, &msb);
> +	if (ret)
> +		return ret;
> +
> +	*data = clamp_t(s32, (msb << 8) | lsb, VADC_MIN_ADC_CODE,
> +			VADC_MAX_ADC_CODE);
> +
> +	return 0;
> +}
> +
> +static struct vadc_channel_prop *vadc_get_channel(struct vadc_priv *vadc,
> +						  int num)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < vadc->nchannels; i++)
> +		if (vadc->chan_props[i].channel == num)
> +			return &vadc->chan_props[i];
> +
> +	dev_dbg(vadc->dev, "no such channel %02x\n", num);
> +
> +	return NULL;
> +}
> +
> +static int vadc_do_conversion(struct vadc_priv *vadc,
> +			      struct vadc_channel_prop *prop, s32 *data)
> +{
> +	unsigned int timeout;
> +	int ret;
> +
> +	ret = vadc_configure(vadc, prop);
> +	if (ret)
> +		return ret;
> +
> +	if (!vadc->poll_eoc)
> +		reinit_completion(&vadc->complete);
> +
> +	ret = vadc_enable(vadc, true);
> +	if (ret)
> +		return ret;
> +
> +	ret = vadc_write(vadc, VADC_CONV_REQ, VADC_CONV_REQ_SET);
> +	if (ret)
> +		goto err_disable;
> +
> +	timeout = BIT(prop->avg_samples) * VADC_CONV_TIME_MIN_US * 2;
> +
> +	if (vadc->poll_eoc) {
> +		ret = vadc_poll_wait_eoc(vadc, timeout);
> +	} else {
> +		ret = wait_for_completion_timeout(&vadc->complete,
> +						  msecs_to_jiffies(1000));
> +		if (!ret) {
> +			ret = -ETIMEDOUT;
> +			goto err_disable;
> +		}
> +
> +		/* double check conversion status */
> +		ret = vadc_poll_wait_eoc(vadc, VADC_CONV_TIME_MIN_US * 2);
> +		if (ret)
> +			goto err_disable;
> +	}
> +
> +	ret = vadc_read_result(vadc, data);
> +
> +err_disable:
> +	vadc_enable(vadc, false);
> +
> +	if (ret)
> +		dev_dbg(vadc->dev, "conversion failed\n");
> +
> +	return ret;
> +}
> +
> +static int vadc_measure_ref_points(struct vadc_priv *vadc)
> +{
> +	struct vadc_channel_prop *prop;
> +	s32 read_1, read_2;
> +	int ret = -EINVAL;
> +
> +	vadc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE_UV;
> +	vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;
> +
> +	prop = vadc_get_channel(vadc, VADC_REF_1250MV);
> +	if (!prop)
> +		goto err;
> +
> +	ret = vadc_do_conversion(vadc, prop, &read_1);
> +	if (ret)
> +		goto err;
> +
> +	/* Try with buffered 625mV channel first */
> +	prop = vadc_get_channel(vadc, VADC_SPARE1);
> +	if (!prop) {
> +		prop = vadc_get_channel(vadc, VADC_REF_625MV);
> +		if (!prop) {
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +	}
> +
> +	ret = vadc_do_conversion(vadc, prop, &read_2);
> +	if (ret)
> +		goto err;
> +
> +	if (read_1 == read_2) {
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	vadc->graph[VADC_CALIB_ABSOLUTE].dy = read_1 - read_2;
> +	vadc->graph[VADC_CALIB_ABSOLUTE].vref = read_1;
> +	vadc->graph[VADC_CALIB_ABSOLUTE].gnd = read_2;
> +
> +	/* Ratiometric calibration */
> +	prop = vadc_get_channel(vadc, VADC_VDD_VADC);
> +	if (!prop) {
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	ret = vadc_do_conversion(vadc, prop, &read_1);
> +	if (ret)
> +		goto err;
> +
> +	prop = vadc_get_channel(vadc, VADC_GND_REF);
> +	if (!prop) {
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	ret = vadc_do_conversion(vadc, prop, &read_2);
> +	if (ret)
> +		goto err;
> +
> +	if (read_1 == read_2) {
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	vadc->graph[VADC_CALIB_RATIOMETRIC].dy = read_1 - read_2;
> +	vadc->graph[VADC_CALIB_RATIOMETRIC].vref = read_1;
> +	vadc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_2;
> +err:
> +	if (ret)
> +		dev_dbg(vadc->dev, "measure reference points failed\n");
> +
> +	return ret;
> +}
> +
> +static s64 vadc_calibrate(struct vadc_priv *vadc,
> +			  const struct vadc_channel_prop *prop, s32 adc_code)
> +{
> +	const struct vadc_prescale_ratio *prescale;
> +	bool negative = false;
> +	s64 voltage;
> +
> +	voltage = adc_code - vadc->graph[prop->calibration].gnd;
> +	voltage *= vadc->graph[prop->calibration].dx;
> +
> +	if (voltage < 0) {
> +		negative = true;
> +		voltage = -voltage;
> +	}
> +
> +	voltage = div_s64(voltage, vadc->graph[prop->calibration].dy);
> +	if (negative)
> +		voltage = -voltage;
> +
> +	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 div_s64(voltage, prescale->num);
> +}
> +
> +static int vadc_decimation_from_dt(u32 value)
> +{
> +	if (!is_power_of_2(value) || !value || value < VADC_DECIMATION_MIN ||
> +	    value > VADC_DECIMATION_MAX)
> +		return -EINVAL;
> +
> +	return __ffs64(value / VADC_DECIMATION_MIN);
> +}
> +
> +static int vadc_prescaling_from_dt(u32 num, u32 den)
> +{
> +	unsigned int pre;
> +
> +	for (pre = 0; pre < ARRAY_SIZE(vadc_prescale_ratios); pre++)
> +		if (vadc_prescale_ratios[pre].num == num &&
> +		    vadc_prescale_ratios[pre].den == den)
> +			break;
> +
> +	if (pre == ARRAY_SIZE(vadc_prescale_ratios))
> +		return -EINVAL;
> +
> +	return pre;
> +}
> +
> +static int vadc_hw_settle_time_from_dt(u32 value)
> +{
> +	if ((value <= 1000 && value % 100) || (value > 1000 && value % 2000))
> +		return -EINVAL;
> +
> +	if (value <= 1000)
> +		value /= 100;
> +	else
> +		value = value / 2000 + 10;
> +
> +	return value;
> +}
> +
> +static int vadc_avg_samples_from_dt(u32 value)
> +{
> +	if (!is_power_of_2(value) || !value || value > VADC_AVG_SAMPLES_MAX)
> +		return -EINVAL;
> +
> +	return __ffs64(value);
> +}
> +
> +static int vadc_read_raw(struct iio_dev *indio_dev,
> +			 struct iio_chan_spec const *chan, int *val, int *val2,
> +			 long mask)
> +{
> +	struct vadc_priv *vadc = iio_priv(indio_dev);
> +	struct vadc_channel_prop *prop;
> +	s32 adc_code;
> +	int ret;
> +
> +	if (!vadc->are_ref_measured) {
> +		ret = vadc_measure_ref_points(vadc);
> +		if (ret)
> +			return ret;
> +
> +		vadc->are_ref_measured = true;
> +	}
> +
> +	if (mask == IIO_CHAN_INFO_PROCESSED || mask == IIO_CHAN_INFO_RAW) {
> +		prop = &vadc->chan_props[chan->address];
> +
> +		ret = vadc_do_conversion(vadc, prop, &adc_code);
> +		if (ret)
> +			return ret;
> +
> +		*val = vadc_calibrate(vadc, prop, adc_code);
> +	}
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_PROCESSED:
> +		if (chan->type != IIO_TEMP && chan->channel != VADC_DIE_TEMP)
> +			return -EINVAL;
> +
> +		/* 2mV/K, return milliCelsius */
> +		*val /= 2;
> +		*val -= KELVINMIL_CELSIUSMIL;
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_RAW:
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 0;
> +		*val2 = 1000;
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	default:
> +		break;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info vadc_info = {
> +	.read_raw = vadc_read_raw,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +struct vadc_channels {
> +	const char *datasheet_name;
> +	unsigned int prescale_index;
> +	enum iio_chan_type type;
> +	long info_mask;
> +};
> +
> +#define VADC_CHAN(_dname, _type, _mask, _pre)				\
> +	[VADC_##_dname] = {						\
> +		.datasheet_name = __stringify(_dname),			\
> +		.prescale_index = _pre,					\
> +		.type = _type,						\
> +		.info_mask = _mask					\
> +	},								\
> +
> +#define VADC_CHAN_TEMP(_dname, _pre)					\
> +	VADC_CHAN(_dname, IIO_TEMP, BIT(IIO_CHAN_INFO_PROCESSED), _pre)	\
> +
> +#define VADC_CHAN_VOLT(_dname, _pre)					\
> +	VADC_CHAN(_dname, IIO_VOLTAGE,					\
> +		  BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),	\
> +		  _pre)							\
> +
> +/*
> + * The array represents all possible ADC channels found in the supported PMICs.
> + * Every index in the array is equal to the channel number per datasheet. The
> + * gaps in the array should be treated as reserved channels.
> + */
> +static const struct vadc_channels vadc_chans[] = {
> +	VADC_CHAN_VOLT(USBIN, 4)
> +	VADC_CHAN_VOLT(DCIN, 4)
> +	VADC_CHAN_VOLT(VCHG_SNS, 3)
> +	VADC_CHAN_VOLT(SPARE1_03, 1)
> +	VADC_CHAN_VOLT(USB_ID_MV, 1)
> +	VADC_CHAN_VOLT(VCOIN, 1)
> +	VADC_CHAN_VOLT(VBAT_SNS, 1)
> +	VADC_CHAN_VOLT(VSYS, 1)
> +	VADC_CHAN_TEMP(DIE_TEMP, 0)
> +	VADC_CHAN_VOLT(REF_625MV, 0)
> +	VADC_CHAN_VOLT(REF_1250MV, 0)
> +	VADC_CHAN_VOLT(CHG_TEMP, 0)
> +	VADC_CHAN_VOLT(SPARE1, 0)
> +	VADC_CHAN_VOLT(SPARE2, 0)
> +	VADC_CHAN_VOLT(GND_REF, 0)
> +	VADC_CHAN_VOLT(VDD_VADC, 0)
> +
> +	VADC_CHAN_VOLT(P_MUX1_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX2_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX3_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX4_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX5_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX6_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX7_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX8_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX9_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX10_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX11_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX12_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX13_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX14_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX15_1_1, 0)
> +	VADC_CHAN_VOLT(P_MUX16_1_1, 0)
> +
> +	VADC_CHAN_VOLT(P_MUX1_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX2_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX3_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX4_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX5_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX6_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX7_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX8_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX9_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX10_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX11_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX12_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX13_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX14_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX15_1_3, 1)
> +	VADC_CHAN_VOLT(P_MUX16_1_3, 1)
> +
> +	VADC_CHAN_VOLT(LR_MUX1_BAT_THERM, 0)
> +	VADC_CHAN_VOLT(LR_MUX2_BAT_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX3_XO_THERM, 0)
> +	VADC_CHAN_VOLT(LR_MUX4_AMUX_THM1, 0)
> +	VADC_CHAN_VOLT(LR_MUX5_AMUX_THM2, 0)
> +	VADC_CHAN_VOLT(LR_MUX6_AMUX_THM3, 0)
> +	VADC_CHAN_VOLT(LR_MUX7_HW_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX8_AMUX_THM4, 0)
> +	VADC_CHAN_VOLT(LR_MUX9_AMUX_THM5, 0)
> +	VADC_CHAN_VOLT(LR_MUX10_USB_ID, 0)
> +	VADC_CHAN_VOLT(AMUX_PU1, 0)
> +	VADC_CHAN_VOLT(AMUX_PU2, 0)
> +	VADC_CHAN_VOLT(LR_MUX3_BUF_XO_THERM, 0)
> +
> +	VADC_CHAN_VOLT(LR_MUX1_PU1_BAT_THERM, 0)
> +	VADC_CHAN_VOLT(LR_MUX2_PU1_BAT_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX3_PU1_XO_THERM, 0)
> +	VADC_CHAN_VOLT(LR_MUX4_PU1_AMUX_THM1, 0)
> +	VADC_CHAN_VOLT(LR_MUX5_PU1_AMUX_THM2, 0)
> +	VADC_CHAN_VOLT(LR_MUX6_PU1_AMUX_THM3, 0)
> +	VADC_CHAN_VOLT(LR_MUX7_PU1_AMUX_HW_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX8_PU1_AMUX_THM4, 0)
> +	VADC_CHAN_VOLT(LR_MUX9_PU1_AMUX_THM5, 0)
> +	VADC_CHAN_VOLT(LR_MUX10_PU1_AMUX_USB_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_XO_THERM, 0)
> +
> +	VADC_CHAN_VOLT(LR_MUX1_PU2_BAT_THERM, 0)
> +	VADC_CHAN_VOLT(LR_MUX2_PU2_BAT_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX3_PU2_XO_THERM, 0)
> +	VADC_CHAN_VOLT(LR_MUX4_PU2_AMUX_THM1, 0)
> +	VADC_CHAN_VOLT(LR_MUX5_PU2_AMUX_THM2, 0)
> +	VADC_CHAN_VOLT(LR_MUX6_PU2_AMUX_THM3, 0)
> +	VADC_CHAN_VOLT(LR_MUX7_PU2_AMUX_HW_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX8_PU2_AMUX_THM4, 0)
> +	VADC_CHAN_VOLT(LR_MUX9_PU2_AMUX_THM5, 0)
> +	VADC_CHAN_VOLT(LR_MUX10_PU2_AMUX_USB_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX3_BUF_PU2_XO_THERM, 0)
> +
> +	VADC_CHAN_VOLT(LR_MUX1_PU1_PU2_BAT_THERM, 0)
> +	VADC_CHAN_VOLT(LR_MUX2_PU1_PU2_BAT_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX3_PU1_PU2_XO_THERM, 0)
> +	VADC_CHAN_VOLT(LR_MUX4_PU1_PU2_AMUX_THM1, 0)
> +	VADC_CHAN_VOLT(LR_MUX5_PU1_PU2_AMUX_THM2, 0)
> +	VADC_CHAN_VOLT(LR_MUX6_PU1_PU2_AMUX_THM3, 0)
> +	VADC_CHAN_VOLT(LR_MUX7_PU1_PU2_AMUX_HW_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX8_PU1_PU2_AMUX_THM4, 0)
> +	VADC_CHAN_VOLT(LR_MUX9_PU1_PU2_AMUX_THM5, 0)
> +	VADC_CHAN_VOLT(LR_MUX10_PU1_PU2_AMUX_USB_ID, 0)
> +	VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_PU2_XO_THERM, 0)
> +};
> +
> +static int vadc_get_dt_channel_data(struct device *dev,
> +				    struct vadc_channel_prop *prop,
> +				    struct device_node *node)
> +{
> +	const char *name = node->name;
> +	u32 chan, value, varr[2];
> +	int ret;
> +
> +	ret = of_property_read_u32(node, "reg", &chan);
> +	if (ret) {
> +		dev_dbg(dev, "invalid channel number %s\n", name);
> +		return ret;
> +	}
> +
> +	if (chan > VADC_CHAN_MAX || chan < VADC_CHAN_MIN) {
> +		dev_dbg(dev, "%s invalid channel number %d\n", name, chan);
> +		return -EINVAL;
> +	}
> +
> +	/* the channel has DT description */
> +	prop->channel = chan;
> +
> +	ret = of_property_read_u32(node, "qcom,decimation", &value);
> +	if (!ret) {
> +		ret = vadc_decimation_from_dt(value);
> +		if (ret < 0) {
> +			dev_dbg(dev, "%02x invalid decimation %d\n",
> +				chan, value);
> +			return ret;
> +		}
> +		prop->decimation = ret;
> +	} else {
> +		prop->decimation = VADC_DEF_DECIMATION;
> +	}
> +
> +	ret = of_property_read_u32_array(node, "qcom,pre-scaling", varr, 2);
> +	if (!ret) {
> +		ret = vadc_prescaling_from_dt(varr[0], varr[1]);
> +		if (ret < 0) {
> +			dev_dbg(dev, "%02x invalid pre-scaling <%d %d>\n",
> +				chan, varr[0], varr[1]);
> +			return ret;
> +		}
> +		prop->prescale = ret;
> +	} else {
> +		prop->prescale = vadc_chans[prop->channel].prescale_index;
> +	}
> +
> +	ret = of_property_read_u32(node, "qcom,hw-settle-time", &value);
> +	if (!ret) {
> +		ret = vadc_hw_settle_time_from_dt(value);
> +		if (ret < 0) {
> +			dev_dbg(dev, "%02x invalid hw-settle-time %d, us\n",
The colon inside the string is probably an unintended leftover?
> +				chan, value);
> +			return ret;
> +		}
> +		prop->hw_settle_time = ret;
> +	} else {
> +		prop->hw_settle_time = VADC_DEF_HW_SETTLE_TIME;
> +	}
> +
> +	ret = of_property_read_u32(node, "qcom,avg-samples", &value);
> +	if (!ret) {
> +		ret = vadc_avg_samples_from_dt(value);
> +		if (ret < 0) {
> +			dev_dbg(dev, "%02x invalid avg-samples %d\n",
> +				chan, value);
> +			return ret;
> +		}
> +		prop->avg_samples = ret;
> +	} else {
> +		prop->avg_samples = VADC_DEF_AVG_SAMPLES;
> +	}
> +
> +	if (of_property_read_bool(node, "qcom,ratiometric"))
> +		prop->calibration = VADC_CALIB_RATIOMETRIC;
> +	else
> +		prop->calibration = VADC_CALIB_ABSOLUTE;
> +
> +	dev_dbg(dev, "%02x name %s\n", chan, name);
> +
> +	return 0;
> +}
> +
> +static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
> +{
> +	struct iio_chan_spec *iio_chan = vadc->iio_chans;
> +	const struct vadc_channels *vadc_chan;
> +	struct vadc_channel_prop prop;
> +	struct device_node *child;
> +	int ret, index = 0;
index could be defined unsigned, as it should only carry unsigned values.
> +
> +	for_each_available_child_of_node(node, child) {
> +		ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
> +		if (ret)
> +			return ret;
> +
> +		vadc->chan_props[index] = prop;
> +
> +		vadc_chan = &vadc_chans[prop.channel];
> +
> +		iio_chan->channel = prop.channel;
> +		iio_chan->datasheet_name = vadc_chan->datasheet_name;
> +		iio_chan->info_mask_separate = vadc_chan->info_mask;
> +		iio_chan->type = vadc_chan->type;
> +		iio_chan->indexed = 1;
> +		iio_chan->scan_type.sign = 's';
> +		iio_chan->scan_type.realbits = 15;
> +		iio_chan->scan_type.storagebits = 16;
> +		iio_chan->address = index++;
> +
> +		iio_chan++;
> +	}
> +
> +	return 0;
> +}
> +
> +static irqreturn_t vadc_isr(int irq, void *dev_id)
> +{
> +	struct vadc_priv *vadc = dev_id;
> +
> +	complete(&vadc->complete);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int vadc_check_revision(struct vadc_priv *vadc)
> +{
> +	u8 val;
> +	int ret;
> +
> +	ret = vadc_read(vadc, VADC_PERPH_TYPE, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (val < VADC_PERPH_TYPE_ADC) {
> +		dev_dbg(vadc->dev, "%d is not ADC\n", val);
> +		return -ENODEV;
> +	}
> +
> +	ret = vadc_read(vadc, VADC_PERPH_SUBTYPE, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (val < VADC_PERPH_SUBTYPE_VADC) {
> +		dev_dbg(vadc->dev, "%d is not VADC\n", val);
> +		return -ENODEV;
> +	}
> +
> +	ret = vadc_read(vadc, VADC_REVISION2, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (val < VADC_REVISION2_SUPPORTED_VADC) {
> +		dev_dbg(vadc->dev, "revision %d not supported\n", val);
> +		return -ENODEV;
> +	}
> +
> +	return 0;
> +}
> +
> +static int vadc_probe(struct platform_device *pdev)
> +{
> +	struct device_node *node = pdev->dev.of_node;
> +	struct device *dev = &pdev->dev;
> +	struct iio_dev *indio_dev;
> +	struct vadc_priv *vadc;
> +	struct resource *res;
> +	struct regmap *regmap;
> +	int ret, irq_eoc;
> +
> +	regmap = dev_get_regmap(dev->parent, NULL);
> +	if (!regmap)
> +		return -ENODEV;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
> +	if (!res)
> +		return -ENODEV;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*vadc));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	vadc = iio_priv(indio_dev);
> +	vadc->regmap = regmap;
> +	vadc->dev = dev;
> +	vadc->base = res->start;
> +	vadc->are_ref_measured = false;
> +	init_completion(&vadc->complete);
> +
> +	ret = vadc_check_revision(vadc);
> +	if (ret)
> +		return ret;
> +
> +	vadc->nchannels = of_get_available_child_count(node);
> +	if (!vadc->nchannels)
> +		return -EINVAL;
> +
> +	vadc->iio_chans = devm_kcalloc(dev, vadc->nchannels,
> +				       sizeof(*vadc->iio_chans), GFP_KERNEL);
> +	if (!vadc->iio_chans)
> +		return -ENOMEM;
> +
> +	vadc->chan_props = devm_kcalloc(dev, vadc->nchannels,
> +					sizeof(*vadc->chan_props), GFP_KERNEL);
> +	if (!vadc->chan_props)
> +		return -ENOMEM;
> +
> +	ret = vadc_get_dt_data(vadc, node);
> +	if (ret)
> +		return ret;
> +
> +	irq_eoc = platform_get_irq(pdev, 0);
> +	if (irq_eoc < 0) {
> +		if (irq_eoc == -EPROBE_DEFER || irq_eoc == -EINVAL)
> +			return irq_eoc;
> +		vadc->poll_eoc = true;
> +	}
> +
Isn't the part below actually the else section of the part above (and device_init_wakeup() belonging up there)?
> +	if (!vadc->poll_eoc) {
> +		ret = devm_request_irq(dev, irq_eoc, vadc_isr,
> +				       IRQF_TRIGGER_RISING, "spmi-vadc", vadc);
> +		if (!ret)
> +			enable_irq_wake(irq_eoc);
> +		else
> +			return ret;
Usually this is done this way:
		if (ret)
			return ret;

		enable_irq_wake(irq_eoc);
> +	} else {
> +		device_init_wakeup(vadc->dev, true);
> +	}
> +
> +	ret = vadc_reset(vadc);
> +	if (ret) {
> +		dev_dbg(dev, "reset failed\n");
> +		return ret;
> +	}
> +
> +	platform_set_drvdata(pdev, vadc);
Why bother to call platform_set_drvdata()?
> +
> +	indio_dev->dev.parent = dev;
> +	indio_dev->dev.of_node = node;
> +	indio_dev->name = pdev->name;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &vadc_info;
> +	indio_dev->channels = vadc->iio_chans;
> +	indio_dev->num_channels = vadc->nchannels;
> +
> +	return devm_iio_device_register(dev, indio_dev);
> +}
> +
> +static const struct of_device_id vadc_match_table[] = {
> +	{ .compatible = "qcom,spmi-vadc" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, vadc_match_table);
> +
> +static struct platform_driver vadc_driver = {
> +	.driver = {
> +		   .name = "spmi-vadc",
> +		   .of_match_table = vadc_match_table,
> +	},
> +	.probe = vadc_probe,
> +};
> +module_platform_driver(vadc_driver);
> +
> +MODULE_ALIAS("platform:spmi-vadc");
> +MODULE_DESCRIPTION("Qualcomm SPMI PMIC voltage ADC driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>");
> +MODULE_AUTHOR("Ivan T. Ivanov <iivanov@mm-sol.com>");
> \ No newline at end of file
What's this ^^^ ?
> diff --git a/include/dt-bindings/iio/qcom,spmi-pmic-vadc.h b/include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
> new file mode 100644
> index 0000000..d543f24
> --- /dev/null
> +++ b/include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
> @@ -0,0 +1,119 @@
> +/*
> + * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _DT_BINDINGS_QCOM_PMIC_ADC_H
> +#define _DT_BINDINGS_QCOM_PMIC_ADC_H
> +
> +/* Voltage ADC channels */
> +#define VADC_USBIN				0x00
> +#define VADC_DCIN				0x01
> +#define VADC_VCHG_SNS				0x02
> +#define VADC_SPARE1_03				0x03
> +#define VADC_USB_ID_MV				0x04
> +#define VADC_VCOIN				0x05
> +#define VADC_VBAT_SNS				0x06
> +#define VADC_VSYS				0x07
> +#define VADC_DIE_TEMP				0x08
> +#define VADC_REF_625MV				0x09
> +#define VADC_REF_1250MV				0x0a
> +#define VADC_CHG_TEMP				0x0b
> +#define VADC_SPARE1				0x0c
> +#define VADC_SPARE2				0x0d
> +#define VADC_GND_REF				0x0e
> +#define VADC_VDD_VADC				0x0f
> +
> +#define VADC_P_MUX1_1_1				0x10
> +#define VADC_P_MUX2_1_1				0x11
> +#define VADC_P_MUX3_1_1				0x12
> +#define VADC_P_MUX4_1_1				0x13
> +#define VADC_P_MUX5_1_1				0x14
> +#define VADC_P_MUX6_1_1				0x15
> +#define VADC_P_MUX7_1_1				0x16
> +#define VADC_P_MUX8_1_1				0x17
> +#define VADC_P_MUX9_1_1				0x18
> +#define VADC_P_MUX10_1_1			0x19
> +#define VADC_P_MUX11_1_1			0x1a
> +#define VADC_P_MUX12_1_1			0x1b
> +#define VADC_P_MUX13_1_1			0x1c
> +#define VADC_P_MUX14_1_1			0x1d
> +#define VADC_P_MUX15_1_1			0x1e
> +#define VADC_P_MUX16_1_1			0x1f
> +
> +#define VADC_P_MUX1_1_3				0x20
> +#define VADC_P_MUX2_1_3				0x21
> +#define VADC_P_MUX3_1_3				0x22
> +#define VADC_P_MUX4_1_3				0x23
> +#define VADC_P_MUX5_1_3				0x24
> +#define VADC_P_MUX6_1_3				0x25
> +#define VADC_P_MUX7_1_3				0x26
> +#define VADC_P_MUX8_1_3				0x27
> +#define VADC_P_MUX9_1_3				0x28
> +#define VADC_P_MUX10_1_3			0x29
> +#define VADC_P_MUX11_1_3			0x2a
> +#define VADC_P_MUX12_1_3			0x2b
> +#define VADC_P_MUX13_1_3			0x2c
> +#define VADC_P_MUX14_1_3			0x2d
> +#define VADC_P_MUX15_1_3			0x2e
> +#define VADC_P_MUX16_1_3			0x2f
> +
> +#define VADC_LR_MUX1_BAT_THERM			0x30
> +#define VADC_LR_MUX2_BAT_ID			0x31
> +#define VADC_LR_MUX3_XO_THERM			0x32
> +#define VADC_LR_MUX4_AMUX_THM1			0x33
> +#define VADC_LR_MUX5_AMUX_THM2			0x34
> +#define VADC_LR_MUX6_AMUX_THM3			0x35
> +#define VADC_LR_MUX7_HW_ID			0x36
> +#define VADC_LR_MUX8_AMUX_THM4			0x37
> +#define VADC_LR_MUX9_AMUX_THM5			0x38
> +#define VADC_LR_MUX10_USB_ID			0x39
> +#define VADC_AMUX_PU1				0x3a
> +#define VADC_AMUX_PU2				0x3b
> +#define VADC_LR_MUX3_BUF_XO_THERM		0x3c
> +
> +#define VADC_LR_MUX1_PU1_BAT_THERM		0x70
> +#define VADC_LR_MUX2_PU1_BAT_ID			0x71
> +#define VADC_LR_MUX3_PU1_XO_THERM		0x72
> +#define VADC_LR_MUX4_PU1_AMUX_THM1		0x73
> +#define VADC_LR_MUX5_PU1_AMUX_THM2		0x74
> +#define VADC_LR_MUX6_PU1_AMUX_THM3		0x75
> +#define VADC_LR_MUX7_PU1_AMUX_HW_ID		0x76
> +#define VADC_LR_MUX8_PU1_AMUX_THM4		0x77
> +#define VADC_LR_MUX9_PU1_AMUX_THM5		0x78
> +#define VADC_LR_MUX10_PU1_AMUX_USB_ID		0x79
> +#define VADC_LR_MUX3_BUF_PU1_XO_THERM		0x7c
> +
> +#define VADC_LR_MUX1_PU2_BAT_THERM		0xb0
> +#define VADC_LR_MUX2_PU2_BAT_ID			0xb1
> +#define VADC_LR_MUX3_PU2_XO_THERM		0xb2
> +#define VADC_LR_MUX4_PU2_AMUX_THM1		0xb3
> +#define VADC_LR_MUX5_PU2_AMUX_THM2		0xb4
> +#define VADC_LR_MUX6_PU2_AMUX_THM3		0xb5
> +#define VADC_LR_MUX7_PU2_AMUX_HW_ID		0xb6
> +#define VADC_LR_MUX8_PU2_AMUX_THM4		0xb7
> +#define VADC_LR_MUX9_PU2_AMUX_THM5		0xb8
> +#define VADC_LR_MUX10_PU2_AMUX_USB_ID		0xb9
> +#define VADC_LR_MUX3_BUF_PU2_XO_THERM		0xbc
> +
> +#define VADC_LR_MUX1_PU1_PU2_BAT_THERM		0xf0
> +#define VADC_LR_MUX2_PU1_PU2_BAT_ID		0xf1
> +#define VADC_LR_MUX3_PU1_PU2_XO_THERM		0xf2
> +#define VADC_LR_MUX4_PU1_PU2_AMUX_THM1		0xf3
> +#define VADC_LR_MUX5_PU1_PU2_AMUX_THM2		0xf4
> +#define VADC_LR_MUX6_PU1_PU2_AMUX_THM3		0xf5
> +#define VADC_LR_MUX7_PU1_PU2_AMUX_HW_ID		0xf6
> +#define VADC_LR_MUX8_PU1_PU2_AMUX_THM4		0xf7
> +#define VADC_LR_MUX9_PU1_PU2_AMUX_THM5		0xf8
> +#define VADC_LR_MUX10_PU1_PU2_AMUX_USB_ID	0xf9
> +#define VADC_LR_MUX3_BUF_PU1_PU2_XO_THERM	0xfc
> +
> +#endif /* _DT_BINDINGS_QCOM_PMIC_ADC_H */
> 

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Hartmut Knaack]

Stanimir Varbanov schrieb am 25.09.2014 17:30:
> Hi Ivan,
> 
> On 09/25/2014 03:47 PM, Ivan T. Ivanov wrote:
>>
>> Hi Stan, few comment bellow.
>>
>> On Wed, 2014-09-24 at 15:56 +0300, Stanimir Varbanov wrote:
>>> The voltage ADC is peripheral of Qualcomm SPMI PMIC chips. It has
>>> 15bits resolution and register space inside PMIC accessible across
>>> SPMI bus.
>>>
>>> The vadc driver registers itself through IIO interface.
>>>
>>> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
>>> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
>>> ---
>>>  drivers/iio/adc/Kconfig                       |   10 +
>>>  drivers/iio/adc/Makefile                      |    1 +
>>>  drivers/iio/adc/qcom-spmi-vadc.c              | 1029 +++++++++++++++++++++++++
>>>  include/dt-bindings/iio/qcom,spmi-pmic-vadc.h |  119 +++
>>>  4 files changed, 1159 insertions(+), 0 deletions(-)
>>>  create mode 100644 drivers/iio/adc/qcom-spmi-vadc.c
>>>  create mode 100644 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
>>>
>>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>>> index 11b048a..ec48360 100644
>>> --- a/drivers/iio/adc/Kconfig
>>> +++ b/drivers/iio/adc/Kconfig
>>> @@ -206,6 +206,16 @@ config NAU7802
>>>  	  To compile this driver as a module, choose M here: the
>>>  	  module will be called nau7802.
>>>  
>>> +config QCOM_SPMI_VADC
>>> +	tristate "Qualcomm SPMI PMIC voltage ADC"
>>> +	depends on SPMI
>>
>> + select REGMAP_SPMI
> 
> I'd suggest MFD_SPMI_PMIC symbol of the parent driver instead? The
> parent MFD PMIC driver already selects REGMAP_SPMI and depends on SPMI.
> 
>>
>> <snip>
>>
>>> +
>>> +static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
>>> +{
>>> +	return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);
>>
>> just regmap_read() ?
> 
> No, regmap_read() expects unsigned int *val as an argument hence I will
> need temporary variable. I had a comment to rework this on the first
> version of the patchset.
> 
>>
>>> +}
>>> +
>>
>> General comment, most of the dev_dbg looks like legitimate dev_err's to me.
> 
> I've decided to not flood console with messages. If someone wants to
> debug why the driver doesn't probed he can define DEBUG.
> 
I would also say that whenever you return an error code, it would be a good idea to replace the dev_dbg with dev_err. It should just rarely occur to have such errors, and if memory consumption is no issue, then I don't see a valid reason to go the full way of recompiling, getting the new kernel(-module) on the device and maybe even reboot.

Re: [PATCH v3 2/2] DT: iio: vadc: document dt binding

[Mark Rutland]

On Wed, Sep 24, 2014 at 01:56:55PM +0100, Stanimir Varbanov wrote:
> Document DT binding for Qualcomm SPMI PMIC voltage ADC
> driver.
> 
> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
> ---
>  .../devicetree/bindings/iio/adc/qcom,spmi-vadc.txt |  130 ++++++++++++++++++++
>  1 files changed, 130 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> new file mode 100644
> index 0000000..fa30300
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> @@ -0,0 +1,130 @@
> +Qualcomm's SPMI PMIC voltage ADC
> +
> +SPMI PMIC voltage ADC (VADC) provides interface to clients to read
> +voltage. A 15 bit ADC is used for voltage measurements. There are multiple
> +peripherals to the VADC and the scope of the driver is to provide interface
> +for the USR peripheral of the VADC.
> +
> +VADC node:
> +
> +- compatible:
> +    Usage: required
> +    Value type: <string>

Technically this is a list of strings.

> +    Definition: Should contain "qcom,spmi-vadc".
> +
> +- reg:
> +    Usage: required
> +    Value type: <u32>

This is an address + size pair, not a u32 (following your example).

> +    Definition: Base address in the SPMI PMIC register map.

And the size, too.

> +
> +- address-cells:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: Must be one.

#address-cells.

What would this cell represent within the ADC?

> +
> +- size-cells:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: Must be zero.

#size-cells.

> +
> +- interrupts:
> +    Usage: optional
> +    Value type: <prop-encoded-array>
> +    Definition: End of conversion interrupt number. If this property does
> +            not exist polling will be used instead.

Just say "end of conversion interrupt". The interrupts property is
standard, and driver behaviour is not a property of the device.

> +
> +- interrupt-names:
> +    Usage: optional
> +    Value type: <string>
> +    Definition: Should contain the interrupt name "eoc" (end of conversion).

If you wish to use interrupt-names, please define interrupts in terms of
interrupt-names so as to make the relationship clear and to avoid
redundancy.

> +
> +Channel node properties:
> +
> +- reg:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: AMUX channel number.
> +            See include/dt-bindings/iio/qcom,spmi-pmic-vadc.h

That header should be part of this patch (and this patch should come
before the driver).

> +
> +- qcom,decimation:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Sampling rate to use for the individual channel measurement.
> +            Quicker measurements can be made by reducing decimation ratio.
> +            Valid values are 512, 1024, 2048, 4096.
> +            If property is not found, default value of 512 will be used.

This description does not make sense. If reducing the value increases
the sampling rate, this property should not be described as the
"sampling rate".

This feels like something that should be runtime configurable rather
than a fixed device property.

> +
> +- qcom,pre-scaling:
> +    Usage: optional
> +    Value type: <u32 array>
> +    Definition: Used for scaling the channel input signal before the signal is
> +            fed to VADC. The configuration for this node is to know the
> +            pre-determined ratio and use it for post scaling. Select one from
> +            the following options.
> +            <1 1>, <1 3>, <1 4>, <1 6>, <1 20>, <1 8>, <10 81>, <1 10>
> +            If property is not found default value depending of chip will be used.
> +
> +- qcom,ratiometric:
> +    Usage: optional
> +    Value type: <empty>
> +    Definition: Channel calibration type. If this property is specified
> +            VADC will use the VDD reference(1.8V) and GND for channel
> +            calibration. If property is not found, channel will be
> +            calibrated with 625mV and 1.25V reference channels.
> +            Otherwise the absolute calibration will be used.

Surely this should be part of the specifier?

> +
> +- qcom,hw-settle-time:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Time between AMUX getting configured and the ADC starting
> +            conversion. Delay = 100us * (value) for value < 11, and
> +            2ms * (value - 10) otherwise.
> +            Valid values are: 0, 100, 200, 300, 400, 500, 600, 700, 800,
> +            900 us and 1, 2, 4, 6, 8, 10 ms
> +            If property is not found, channel will use 0us.
> +
> +- qcom,avg-samples:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Number of samples to be used for measurement.
> +            Fast averaging provides the option to obtain a single measurement
> +            from the ADC that is an average of multiple samples. The value
> +            selected is 2^(value).
> +            Valid values are: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512
> +            If property is not found, 1 sample will be used.

Likewise.

thanks,
Mark.

> +
> +NOTE: At least reference channel nodes are required. The reference channels
> +      might be different depending on PMIC version.
> +      Reference channels per type of calibration are:
> +       - absolute
> +         (VADC_REF_625MV or VADC_SPARE1) and VADC_REF_1250MV
> +       - ratiomatric
> +         VADC_GND_REF and VADC_VDD_VADC
> +
> +Example:
> +	/* VADC node */
> +	pmic_vadc: vadc@3100 {
> +		compatible = "qcom,spmi-vadc";
> +		reg = <0x3100 0x100>;
> +		interrupts = <0x0 0x31 0x0 IRQ_TYPE_EDGE_RISING>;
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		#io-channel-cells = <1>;
> +		io-channel-ranges;
> +
> +		/* Channel node */
> +		usb_id_nopull {
> +			reg = <VADC_LR_MUX10_USB_ID>;
> +			qcom,decimation = <512>;
> +			qcom,ratiometric;
> +			qcom,hw-settle-time = <200>;
> +			qcom,avg-samples = <1>;
> +			qcom,pre-scaling = <1 3>;
> +		};
> +	};
> +
> +	/* IIO client node */
> +	usb {
> +		io-channels = <&pmic_vadc VADC_LR_MUX10_USB_ID>;
> +		io-channel-names = "vadc";
> +	};
> -- 
> 1.7.0.4
> 
> 

Re: [PATCH v3 2/2] DT: iio: vadc: document dt binding

[Stanimir Varbanov]

Thanks for the comments!

On 10/12/2014 02:05 AM, Hartmut Knaack wrote:
> Hi,
> two small issues inline.
> Stanimir Varbanov schrieb am 24.09.2014 14:56:
>> Document DT binding for Qualcomm SPMI PMIC voltage ADC
>> driver.
>>
>> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
>> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
>> ---
>>  .../devicetree/bindings/iio/adc/qcom,spmi-vadc.txt |  130 ++++++++++++++++++++
>>  1 files changed, 130 insertions(+), 0 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
>>
>> diff --git a/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
>> new file mode 100644
>> index 0000000..fa30300
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
>> @@ -0,0 +1,130 @@
>> +Qualcomm's SPMI PMIC voltage ADC
>> +
>> +SPMI PMIC voltage ADC (VADC) provides interface to clients to read
>> +voltage. A 15 bit ADC is used for voltage measurements. There are multiple
>> +peripherals to the VADC and the scope of the driver is to provide interface
>> +for the USR peripheral of the VADC.
>> +
>> +VADC node:
>> +
>> +- compatible:
>> +    Usage: required
>> +    Value type: <string>
>> +    Definition: Should contain "qcom,spmi-vadc".
>> +
>> +- reg:
>> +    Usage: required
>> +    Value type: <u32>
>> +    Definition: Base address in the SPMI PMIC register map.
>> +
>> +- address-cells:
>> +    Usage: required
>> +    Value type: <u32>
>> +    Definition: Must be one.
>> +
>> +- size-cells:
>> +    Usage: required
>> +    Value type: <u32>
>> +    Definition: Must be zero.
>> +
>> +- interrupts:
>> +    Usage: optional
>> +    Value type: <prop-encoded-array>
>> +    Definition: End of conversion interrupt number. If this property does
>> +            not exist polling will be used instead.
>> +
>> +- interrupt-names:
>> +    Usage: optional
>> +    Value type: <string>
>> +    Definition: Should contain the interrupt name "eoc" (end of conversion).
>> +
>> +Channel node properties:
>> +
>> +- reg:
>> +    Usage: required
>> +    Value type: <u32>
>> +    Definition: AMUX channel number.
>> +            See include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
>> +
>> +- qcom,decimation:
>> +    Usage: optional
>> +    Value type: <u32>
>> +    Definition: Sampling rate to use for the individual channel measurement.
>> +            Quicker measurements can be made by reducing decimation ratio.
>> +            Valid values are 512, 1024, 2048, 4096.
>> +            If property is not found, default value of 512 will be used.
>> +
>> +- qcom,pre-scaling:
>> +    Usage: optional
>> +    Value type: <u32 array>
>> +    Definition: Used for scaling the channel input signal before the signal is
>> +            fed to VADC. The configuration for this node is to know the
>> +            pre-determined ratio and use it for post scaling. Select one from
>> +            the following options.
>> +            <1 1>, <1 3>, <1 4>, <1 6>, <1 20>, <1 8>, <10 81>, <1 10>
>> +            If property is not found default value depending of chip will be used.
>> +
>> +- qcom,ratiometric:
>> +    Usage: optional
>> +    Value type: <empty>
>> +    Definition: Channel calibration type. If this property is specified
>> +            VADC will use the VDD reference(1.8V) and GND for channel
> Missing whitespace before opening parenthesis.
>> +            calibration. If property is not found, channel will be
>> +            calibrated with 625mV and 1.25V reference channels.
> There is a slight majority in using V instead of mv (2 : 1), so why not express everything in V?

No worries, will correct.

-- 
regards,
Stan

Re: [PATCH v3 2/2] DT: iio: vadc: document dt binding

[Stanimir Varbanov]

Mark,

Thanks for the comments!

On 10/13/2014 06:00 PM, Mark Rutland wrote:
> On Wed, Sep 24, 2014 at 01:56:55PM +0100, Stanimir Varbanov wrote:
>> Document DT binding for Qualcomm SPMI PMIC voltage ADC
>> driver.
>>
>> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
>> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
>> ---
>>  .../devicetree/bindings/iio/adc/qcom,spmi-vadc.txt |  130 ++++++++++++++++++++
>>  1 files changed, 130 insertions(+), 0 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
>>
>> diff --git a/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
>> new file mode 100644
>> index 0000000..fa30300
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
>> @@ -0,0 +1,130 @@
>> +Qualcomm's SPMI PMIC voltage ADC
>> +
>> +SPMI PMIC voltage ADC (VADC) provides interface to clients to read
>> +voltage. A 15 bit ADC is used for voltage measurements. There are multiple
>> +peripherals to the VADC and the scope of the driver is to provide interface
>> +for the USR peripheral of the VADC.
>> +
>> +VADC node:
>> +
>> +- compatible:
>> +    Usage: required
>> +    Value type: <string>
> 
> Technically this is a list of strings.

true, will correct.

> 
>> +    Definition: Should contain "qcom,spmi-vadc".
>> +
>> +- reg:
>> +    Usage: required
>> +    Value type: <u32>
> 
> This is an address + size pair, not a u32 (following your example).
> 
>> +    Definition: Base address in the SPMI PMIC register map.
> 
> And the size, too.
> 

will rephrase.

>> +
>> +- address-cells:
>> +    Usage: required
>> +    Value type: <u32>
>> +    Definition: Must be one.
> 
> #address-cells.
> 
> What would this cell represent within the ADC?

"reg" property is used to describe ADC channel number in ADC child nodes.

> 
>> +
>> +- size-cells:
>> +    Usage: required
>> +    Value type: <u32>
>> +    Definition: Must be zero.
> 
> #size-cells.
> 
>> +
>> +- interrupts:
>> +    Usage: optional
>> +    Value type: <prop-encoded-array>
>> +    Definition: End of conversion interrupt number. If this property does
>> +            not exist polling will be used instead.
> 
> Just say "end of conversion interrupt". The interrupts property is
> standard, and driver behaviour is not a property of the device.

OK.

> 
>> +
>> +- interrupt-names:
>> +    Usage: optional
>> +    Value type: <string>
>> +    Definition: Should contain the interrupt name "eoc" (end of conversion).
> 
> If you wish to use interrupt-names, please define interrupts in terms of
> interrupt-names so as to make the relationship clear and to avoid
> redundancy.
> 
>> +
>> +Channel node properties:
>> +
>> +- reg:
>> +    Usage: required
>> +    Value type: <u32>
>> +    Definition: AMUX channel number.
>> +            See include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
> 
> That header should be part of this patch (and this patch should come
> before the driver).

Sure will rebase the series.

> 
>> +
>> +- qcom,decimation:
>> +    Usage: optional
>> +    Value type: <u32>
>> +    Definition: Sampling rate to use for the individual channel measurement.
>> +            Quicker measurements can be made by reducing decimation ratio.
>> +            Valid values are 512, 1024, 2048, 4096.
>> +            If property is not found, default value of 512 will be used.
> 
> This description does not make sense. If reducing the value increases
> the sampling rate, this property should not be described as the
> "sampling rate".

I blindly copped above description from codeaurora kernel. From the
above I understand that reducing decimation ratio will decrease
conversion time.

Without go into signal processing theory, what about this:

Definition: Decimation factor per channel. Valid values are 512, 1024,
2048 and 4096.

I'm expecting the reader will be familiar enough how the decimation will
reflect on the data rate and conversion time.

> 
> This feels like something that should be runtime configurable rather
> than a fixed device property.

Currently the IIO hasn't generic way to configure such a properties.

Jonathan, could you share your opinion on that.

> 
>> +
>> +- qcom,pre-scaling:
>> +    Usage: optional
>> +    Value type: <u32 array>
>> +    Definition: Used for scaling the channel input signal before the signal is
>> +            fed to VADC. The configuration for this node is to know the
>> +            pre-determined ratio and use it for post scaling. Select one from
>> +            the following options.
>> +            <1 1>, <1 3>, <1 4>, <1 6>, <1 20>, <1 8>, <10 81>, <1 10>
>> +            If property is not found default value depending of chip will be used.
>> +
>> +- qcom,ratiometric:
>> +    Usage: optional
>> +    Value type: <empty>
>> +    Definition: Channel calibration type. If this property is specified
>> +            VADC will use the VDD reference(1.8V) and GND for channel
>> +            calibration. If property is not found, channel will be
>> +            calibrated with 625mV and 1.25V reference channels.
>> +            Otherwise the absolute calibration will be used.
> 
> Surely this should be part of the specifier?

Do you mean last sentence, if so no I'm not.

> 
>> +
>> +- qcom,hw-settle-time:
>> +    Usage: optional
>> +    Value type: <u32>
>> +    Definition: Time between AMUX getting configured and the ADC starting
>> +            conversion. Delay = 100us * (value) for value < 11, and
>> +            2ms * (value - 10) otherwise.
>> +            Valid values are: 0, 100, 200, 300, 400, 500, 600, 700, 800,
>> +            900 us and 1, 2, 4, 6, 8, 10 ms
>> +            If property is not found, channel will use 0us.
>> +
>> +- qcom,avg-samples:
>> +    Usage: optional
>> +    Value type: <u32>
>> +    Definition: Number of samples to be used for measurement.
>> +            Fast averaging provides the option to obtain a single measurement
>> +            from the ADC that is an average of multiple samples. The value
>> +            selected is 2^(value).
>> +            Valid values are: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512
>> +            If property is not found, 1 sample will be used.
> 
> Likewise.

ditto

> 
> thanks,
> Mark.


-- 
regards,
Stan

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Stanimir Varbanov]

On 10/13/2014 01:07 AM, Hartmut Knaack wrote:
> Stanimir Varbanov schrieb am 24.09.2014 14:56:
>> The voltage ADC is peripheral of Qualcomm SPMI PMIC chips. It has
>> 15bits resolution and register space inside PMIC accessible across
>> SPMI bus.
>>
>> The vadc driver registers itself through IIO interface.
> Quite a lot of changes. Please see my comments inline.
>>
>> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
>> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
>> ---
>>  drivers/iio/adc/Kconfig                       |   10 +
>>  drivers/iio/adc/Makefile                      |    1 +
>>  drivers/iio/adc/qcom-spmi-vadc.c              | 1029 +++++++++++++++++++++++++
>>  include/dt-bindings/iio/qcom,spmi-pmic-vadc.h |  119 +++
>>  4 files changed, 1159 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/iio/adc/qcom-spmi-vadc.c
>>  create mode 100644 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
>>

<snip>

>> +
>> +static int vadc_reset(struct vadc_priv *vadc)
>> +{
>> +	u8 data;
>> +	int ret;
>> +
>> +	ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = vadc_read(vadc, VADC_PERH_RESET_CTL3, &data);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
>> +	if (ret)
>> +		return ret;
>> +
>> +	data |= VADC_FOLLOW_WARM_RB;
>> +
>> +	return vadc_write(vadc, VADC_PERH_RESET_CTL3, data);
>> +}
>> +
>> +static int vadc_enable(struct vadc_priv *vadc, bool state)
>> +{
>> +	return vadc_write(vadc, VADC_EN_CTL1, state ? VADC_EN_CTL1_SET : 0);
>> +}
>> +
>> +#ifdef DEBUG
>> +static void vadc_show_status(struct vadc_priv *vadc)
>> +{
> You could also move the #ifdef in here...
>> +	u8 mode, sta1, chan, dig, en, req;
>> +	int ret;
>> +
>> +	ret = vadc_read(vadc, VADC_MODE_CTL, &mode);
>> +	if (ret)
>> +		return;
>> +
>> +	ret = vadc_read(vadc, VADC_ADC_DIG_PARAM, &dig);
>> +	if (ret)
>> +		return;
>> +
>> +	ret = vadc_read(vadc, VADC_ADC_CH_SEL_CTL, &chan);
>> +	if (ret)
>> +		return;
>> +
>> +	ret = vadc_read(vadc, VADC_CONV_REQ, &req);
>> +	if (ret)
>> +		return;
>> +
>> +	ret = vadc_read(vadc, VADC_STATUS1, &sta1);
>> +	if (ret)
>> +		return;
>> +
>> +	ret = vadc_read(vadc, VADC_EN_CTL1, &en);
>> +	if (ret)
>> +		return;
>> +
>> +	dev_dbg(vadc->dev,
>> +		"mode:%02x en:%02x chan:%02x dig:%02x req:%02x sta1:%02x\n",
>> +		mode, en, chan, dig, req, sta1);
> ...and the #endif here. Saves 2 lines of code ;-)

I don't like #ifdefs in function body, it makes code unreadable at least
for me :)

>> +}
>> +#else
>> +static void vadc_show_status(struct vadc_priv *vadc) {}
>> +#endif
>> +

<snip>

>> +
>> +static int vadc_get_dt_channel_data(struct device *dev,
>> +				    struct vadc_channel_prop *prop,
>> +				    struct device_node *node)
>> +{
>> +	const char *name = node->name;
>> +	u32 chan, value, varr[2];
>> +	int ret;
>> +
>> +	ret = of_property_read_u32(node, "reg", &chan);
>> +	if (ret) {
>> +		dev_dbg(dev, "invalid channel number %s\n", name);
>> +		return ret;
>> +	}
>> +
>> +	if (chan > VADC_CHAN_MAX || chan < VADC_CHAN_MIN) {
>> +		dev_dbg(dev, "%s invalid channel number %d\n", name, chan);
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* the channel has DT description */
>> +	prop->channel = chan;
>> +
>> +	ret = of_property_read_u32(node, "qcom,decimation", &value);
>> +	if (!ret) {
>> +		ret = vadc_decimation_from_dt(value);
>> +		if (ret < 0) {
>> +			dev_dbg(dev, "%02x invalid decimation %d\n",
>> +				chan, value);
>> +			return ret;
>> +		}
>> +		prop->decimation = ret;
>> +	} else {
>> +		prop->decimation = VADC_DEF_DECIMATION;
>> +	}
>> +
>> +	ret = of_property_read_u32_array(node, "qcom,pre-scaling", varr, 2);
>> +	if (!ret) {
>> +		ret = vadc_prescaling_from_dt(varr[0], varr[1]);
>> +		if (ret < 0) {
>> +			dev_dbg(dev, "%02x invalid pre-scaling <%d %d>\n",
>> +				chan, varr[0], varr[1]);
>> +			return ret;
>> +		}
>> +		prop->prescale = ret;
>> +	} else {
>> +		prop->prescale = vadc_chans[prop->channel].prescale_index;
>> +	}
>> +
>> +	ret = of_property_read_u32(node, "qcom,hw-settle-time", &value);
>> +	if (!ret) {
>> +		ret = vadc_hw_settle_time_from_dt(value);
>> +		if (ret < 0) {
>> +			dev_dbg(dev, "%02x invalid hw-settle-time %d, us\n",
> The colon inside the string is probably an unintended leftover?

correct.

>> +				chan, value);
>> +			return ret;
>> +		}
>> +		prop->hw_settle_time = ret;
>> +	} else {
>> +		prop->hw_settle_time = VADC_DEF_HW_SETTLE_TIME;
>> +	}
>> +
>> +	ret = of_property_read_u32(node, "qcom,avg-samples", &value);
>> +	if (!ret) {
>> +		ret = vadc_avg_samples_from_dt(value);
>> +		if (ret < 0) {
>> +			dev_dbg(dev, "%02x invalid avg-samples %d\n",
>> +				chan, value);
>> +			return ret;
>> +		}
>> +		prop->avg_samples = ret;
>> +	} else {
>> +		prop->avg_samples = VADC_DEF_AVG_SAMPLES;
>> +	}
>> +
>> +	if (of_property_read_bool(node, "qcom,ratiometric"))
>> +		prop->calibration = VADC_CALIB_RATIOMETRIC;
>> +	else
>> +		prop->calibration = VADC_CALIB_ABSOLUTE;
>> +
>> +	dev_dbg(dev, "%02x name %s\n", chan, name);
>> +
>> +	return 0;
>> +}
>> +
>> +static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
>> +{
>> +	struct iio_chan_spec *iio_chan = vadc->iio_chans;
>> +	const struct vadc_channels *vadc_chan;
>> +	struct vadc_channel_prop prop;
>> +	struct device_node *child;
>> +	int ret, index = 0;
> index could be defined unsigned, as it should only carry unsigned values.

makes sense.

>> +
>> +	for_each_available_child_of_node(node, child) {
>> +		ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
>> +		if (ret)
>> +			return ret;
>> +
>> +		vadc->chan_props[index] = prop;
>> +
>> +		vadc_chan = &vadc_chans[prop.channel];
>> +
>> +		iio_chan->channel = prop.channel;
>> +		iio_chan->datasheet_name = vadc_chan->datasheet_name;
>> +		iio_chan->info_mask_separate = vadc_chan->info_mask;
>> +		iio_chan->type = vadc_chan->type;
>> +		iio_chan->indexed = 1;
>> +		iio_chan->scan_type.sign = 's';
>> +		iio_chan->scan_type.realbits = 15;
>> +		iio_chan->scan_type.storagebits = 16;
>> +		iio_chan->address = index++;
>> +
>> +		iio_chan++;
>> +	}
>> +
>> +	return 0;
>> +}
>> +

<snip>

>> +
>> +static int vadc_probe(struct platform_device *pdev)
>> +{
>> +	struct device_node *node = pdev->dev.of_node;
>> +	struct device *dev = &pdev->dev;
>> +	struct iio_dev *indio_dev;
>> +	struct vadc_priv *vadc;
>> +	struct resource *res;
>> +	struct regmap *regmap;
>> +	int ret, irq_eoc;
>> +
>> +	regmap = dev_get_regmap(dev->parent, NULL);
>> +	if (!regmap)
>> +		return -ENODEV;
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
>> +	if (!res)
>> +		return -ENODEV;
>> +
>> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*vadc));
>> +	if (!indio_dev)
>> +		return -ENOMEM;
>> +
>> +	vadc = iio_priv(indio_dev);
>> +	vadc->regmap = regmap;
>> +	vadc->dev = dev;
>> +	vadc->base = res->start;
>> +	vadc->are_ref_measured = false;
>> +	init_completion(&vadc->complete);
>> +
>> +	ret = vadc_check_revision(vadc);
>> +	if (ret)
>> +		return ret;
>> +
>> +	vadc->nchannels = of_get_available_child_count(node);
>> +	if (!vadc->nchannels)
>> +		return -EINVAL;
>> +
>> +	vadc->iio_chans = devm_kcalloc(dev, vadc->nchannels,
>> +				       sizeof(*vadc->iio_chans), GFP_KERNEL);
>> +	if (!vadc->iio_chans)
>> +		return -ENOMEM;
>> +
>> +	vadc->chan_props = devm_kcalloc(dev, vadc->nchannels,
>> +					sizeof(*vadc->chan_props), GFP_KERNEL);
>> +	if (!vadc->chan_props)
>> +		return -ENOMEM;
>> +
>> +	ret = vadc_get_dt_data(vadc, node);
>> +	if (ret)
>> +		return ret;
>> +
>> +	irq_eoc = platform_get_irq(pdev, 0);
>> +	if (irq_eoc < 0) {
>> +		if (irq_eoc == -EPROBE_DEFER || irq_eoc == -EINVAL)
>> +			return irq_eoc;
>> +		vadc->poll_eoc = true;
>> +	}
>> +
> Isn't the part below actually the else section of the part above (and device_init_wakeup() belonging up there)?

you are right, might be I wanted to avoid indentation issues. Will see
how to make it better.

>> +	if (!vadc->poll_eoc) {
>> +		ret = devm_request_irq(dev, irq_eoc, vadc_isr,
>> +				       IRQF_TRIGGER_RISING, "spmi-vadc", vadc);
>> +		if (!ret)
>> +			enable_irq_wake(irq_eoc);
>> +		else
>> +			return ret;
> Usually this is done this way:

yes, I know just oversight it.

> 		if (ret)
> 			return ret;
> 
> 		enable_irq_wake(irq_eoc);
>> +	} else {
>> +		device_init_wakeup(vadc->dev, true);
>> +	}
>> +
>> +	ret = vadc_reset(vadc);
>> +	if (ret) {
>> +		dev_dbg(dev, "reset failed\n");
>> +		return ret;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, vadc);
> Why bother to call platform_set_drvdata()?

Seems leftover, will delete.

-- 
regards,
Stan

Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

[Ivan T. Ivanov]

Hi, 

On Sat, 2014-10-04 at 12:51 +0100, Jonathan Cameron wrote:
> On 02/10/14 13:08, Ivan T. Ivanov wrote:
> >  +iio maintainers
> > 
> >  On Thu, 2014-10-02 at 12:29 +0300, Ivan T. Ivanov wrote:
> > >  Hi Stan,
> > > >
> > >  On 09/24/2014 03:56 PM, Stanimir Varbanov wrote:
> > > >
> > >  <snip>
> > > >
> > > >  +static int vadc_get_dt_data(struct vadc_priv *vadc, struct 
> > > > device_node *node)
> > > >  +{
> > > >  +      struct iio_chan_spec *iio_chan = vadc->iio_chans;
> > > >  +      const struct vadc_channels *vadc_chan;
> > > >  +      struct vadc_channel_prop prop;
> > > >  +      struct device_node *child;
> > > >  +      int ret, index = 0;
> > > >  +
> > > >  +      for_each_available_child_of_node(node, child) {
> > > >  +      ret = vadc_get_dt_channel_data(vadc->dev, &prop, 
> > > > child);
> > > >  +      if (ret)
> > > >  +      return ret;
> > > >  +
> > > >  +      vadc->chan_props[index] = prop;
> > > >  +
> > > >  +      vadc_chan = &vadc_chans[prop.channel];
> > > >  +
> > > >  +      iio_chan->channel = prop.channel;
> > > >  +      iio_chan->datasheet_name = vadc_chan->datasheet_name;
> > > >  +      iio_chan->info_mask_separate = vadc_chan->info_mask;
> > > >  +      iio_chan->type = vadc_chan->type;
> > > >  +      iio_chan->indexed = 1;
> > > >  +      iio_chan->scan_type.sign = 's';
> > > >  +      iio_chan->scan_type.realbits = 15;
> > > >  +      iio_chan->scan_type.storagebits = 16;
> > > >  +      iio_chan->address = index++;
> > > >  +
> > > >  +      iio_chan++;
> > > >  +      }
> > > >  +
> > > >  +      return 0;
> > > >  +}
> > > >  +
> > > >
> > >  <snip>
> > > >
> > > >  +static int vadc_probe(struct platform_device *pdev)
> > > >  +{
> > > >
> > >  <snip>
> > > >
> > > >  +
> > > >  +      indio_dev->dev.parent = dev;
> > > >  +      indio_dev->dev.of_node = node;
> > > >  +      indio_dev->name = pdev->name;
> > > >  +      indio_dev->modes = INDIO_DIRECT_MODE;
> > > >  +      indio_dev->info = &vadc_info;
> > > >  +      indio_dev->channels = vadc->iio_chans;
> > > >  +      indio_dev->num_channels = vadc->nchannels;
> > > >
> > >  This will not work as we thought. Registration will be fine and 
> > > entries
> > >  in sysfs are created as expected, but this is breaking 
> > > numbering scheme
> > >  for client drivers. For us the problem is that iio framework 
> > > expect channels
> > >  numbering to be linear and channel number should not be greater 
> > > than
> > >  channel count. For example even if die temperature channel is 
> > > always 8, if
> > >  I describe only 5 channels in DTS files (4 for reference points 
> > > measurement)
> > >  and 1 for die temperature, clients could not get OF reference to
> > >  temperature
> > >  channel using io-channels = <&pm8941_vadc 8>;
> > > >
> > >  Jonathan, please, could you advise us.
> I'd like to let the solution you proposed sit on the list a little 
> longer.
> It seems fairly sensible, but lets see what others suggest.

It is quiet :-) Just for the record the same aproach is used in
PWM, Reset, Gpio and PHY frameworks.

Patch in question: https://lkml.org/lkml/2014/10/2/199

Regards,
Ivan


> 
> Jonathan