[PATCH v4 0/2] iio: dac: AD5770R: Add support

[PATCH v4 0/2] iio: dac: AD5770R: Add support

[Alexandru Tachici]

This series of patches adds support for the AD5570R
14-bit current DAC.

Changelog V3 -> V4:

- make use of GENMASK in defines
- added a DMA safe buffer for regmap_bulk_read/writeval
- removed of_match_ptr
- removed DVdd supply from dt bindings as the datasheet
specifies that must have same voltage as AVdd

Alexandru Tachici (2):
  iio: dac: ad5770r: Add AD5770R support
  dt-bindings: iio: dac: Add docs for AD5770R DAC

 .../bindings/iio/dac/adi,ad5770r.yaml         | 188 +++++
 drivers/iio/dac/Kconfig                       |  10 +
 drivers/iio/dac/Makefile                      |   1 +
 drivers/iio/dac/ad5770r.c                     | 695 ++++++++++++++++++
 4 files changed, 894 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
 create mode 100644 drivers/iio/dac/ad5770r.c

-- 
2.20.1

[PATCH v4 1/2] iio: dac: ad5770r: Add AD5770R support

[Alexandru Tachici]

The AD5770R is a 6-channel, 14-bit resolution, low noise, programmable
current output digital-to-analog converter (DAC) for photonics control
applications.

It contains five 14-bit resolution current sourcing DAC channels and one
14-bit resolution current sourcing/sinking DAC channel.

Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
---
 drivers/iio/dac/Kconfig   |  10 +
 drivers/iio/dac/Makefile  |   1 +
 drivers/iio/dac/ad5770r.c | 695 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 706 insertions(+)
 create mode 100644 drivers/iio/dac/ad5770r.c

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 979070196da9..c74f2151ee42 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -208,6 +208,16 @@ config AD5764
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad5764.
 
+config AD5770R
+	tristate "Analog Devices AD5770R IDAC driver"
+	depends on SPI_MASTER
+	help
+	  Say yes here to build support for Analog Devices AD5770R Digital to
+	  Analog Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad5770r.
+
 config AD5791
 	tristate "Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC SPI driver"
 	depends on SPI
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 1369fa1d2f0e..2fc481167724 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_AD5755) += ad5755.o
 obj-$(CONFIG_AD5755) += ad5758.o
 obj-$(CONFIG_AD5761) += ad5761.o
 obj-$(CONFIG_AD5764) += ad5764.o
+obj-$(CONFIG_AD5770R) += ad5770r.o
 obj-$(CONFIG_AD5791) += ad5791.o
 obj-$(CONFIG_AD5686) += ad5686.o
 obj-$(CONFIG_AD5686_SPI) += ad5686-spi.o
diff --git a/drivers/iio/dac/ad5770r.c b/drivers/iio/dac/ad5770r.c
new file mode 100644
index 000000000000..0ca2f69644ea
--- /dev/null
+++ b/drivers/iio/dac/ad5770r.c
@@ -0,0 +1,695 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * AD5770R Digital to analog converters driver
+ *
+ * Copyright 2018 Analog Devices Inc.
+ */
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#define ADI_SPI_IF_CONFIG_A		0x00
+#define ADI_SPI_IF_CONFIG_B		0x01
+#define ADI_SPI_IF_DEVICE_CONFIG	0x02
+#define ADI_SPI_IF_CHIP_TYPE		0x03
+#define ADI_SPI_IF_PRODUCT_ID_L		0x04
+#define ADI_SPI_IF_PRODUCT_ID_H		0x05
+#define ADI_SPI_IF_CHIP_GRADE		0x06
+#define ADI_SPI_IF_SCRACTH_PAD		0x0A
+#define ADI_SPI_IF_SPI_REVISION		0x0B
+#define ADI_SPI_IF_SPI_VENDOR_L		0x0C
+#define ADI_SPI_IF_SPI_VENDOR_H		0x0D
+#define ADI_SPI_IF_SPI_STREAM_MODE	0x0E
+#define ADI_SPI_IF_CONFIG_C		0x10
+#define ADI_SPI_IF_STATUS_A		0x11
+
+/* ADI_SPI_IF_CONFIG_A */
+#define ADI_SPI_IF_SW_RESET_MSK		(BIT(0) | BIT(7))
+#define ADI_SPI_IF_SW_RESET_SEL(x)	((x) & ADI_SPI_IF_SW_RESET_MSK)
+#define ADI_SPI_IF_ADDR_ASC_MSK		(BIT(2) | BIT(5))
+#define ADI_SPI_IF_ADDR_ASC_SEL(x)	(((x) << 2) & ADI_SPI_IF_ADDR_ASC_MSK)
+
+/* ADI_SPI_IF_CONFIG_B */
+#define ADI_SPI_IF_SINGLE_INS_MSK	BIT(7)
+#define ADI_SPI_IF_SINGLE_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
+#define ADI_SPI_IF_SHORT_INS_MSK	BIT(7)
+#define ADI_SPI_IF_SHORT_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
+
+/* ADI_SPI_IF_CONFIG_C */
+#define ADI_SPI_IF_STRICT_REG_MSK	BIT(5)
+#define ADI_SPI_IF_STRICT_REG_GET(x)	FIELD_GET(ADI_SPI_IF_STRICT_REG_MSK, x)
+
+/* AD5770R configuration registers */
+#define AD5770R_CHANNEL_CONFIG		0x14
+#define AD5770R_OUTPUT_RANGE(ch)	(0x15 + (ch))
+#define AD5770R_FILTER_RESISTOR(ch)	(0x1D + (ch))
+#define AD5770R_REFERENCE		0x1B
+#define AD5770R_DAC_LSB(ch)		(0x26 + 2 * (ch))
+#define AD5770R_DAC_MSB(ch)		(0x27 + 2 * (ch))
+#define AD5770R_CH_SELECT		0x34
+#define AD5770R_CH_ENABLE		0x44
+
+/* AD5770R_CHANNEL_CONFIG */
+#define AD5770R_CFG_CH0_SINK_EN(x)		(((x) & 0x1) << 7)
+#define AD5770R_CFG_SHUTDOWN_B(x, ch)		(((x) & 0x1) << (ch))
+
+/* AD5770R_OUTPUT_RANGE */
+#define AD5770R_RANGE_OUTPUT_SCALING(x)		(((x) & GENMASK(5, 0)) << 2)
+#define AD5770R_RANGE_MODE(x)			((x) & GENMASK(1, 0))
+
+/* AD5770R_REFERENCE */
+#define AD5770R_REF_RESISTOR_SEL(x)		(((x) & 0x1) << 2)
+#define AD5770R_REF_SEL(x)			((x) & GENMASK(1, 0))
+
+/* AD5770R_CH_ENABLE */
+#define AD5770R_CH_SET(x, ch)		(((x) & 0x1) << (ch))
+
+#define AD5770R_MAX_CHANNELS	6
+#define AD5770R_MAX_CH_MODES	14
+#define AD5770R_LOW_VREF_mV	1250
+#define AD5770R_HIGH_VREF_mV	2500
+
+enum ad5770r_ch0_modes {
+	AD5770R_CH0_0_300 = 0,
+	AD5770R_CH0_NEG_60_0,
+	AD5770R_CH0_NEG_60_300
+};
+
+enum ad5770r_ch1_modes {
+	AD5770R_CH1_0_140_LOW_HEAD = 1,
+	AD5770R_CH1_0_140_LOW_NOISE,
+	AD5770R_CH1_0_250
+};
+
+enum ad5770r_ch2_5_modes {
+	AD5770R_CH_LOW_RANGE = 0,
+	AD5770R_CH_HIGH_RANGE
+};
+
+enum ad5770r_ref_v {
+	AD5770R_EXT_2_5_V = 0,
+	AD5770R_INT_1_25_V_OUT_ON,
+	AD5770R_EXT_1_25_V,
+	AD5770R_INT_1_25_V_OUT_OFF
+};
+
+enum ad5770r_output_filter_resistor {
+	AD5770R_FILTER_60_OHM = 0x0,
+	AD5770R_FILTER_5_6_KOHM = 0x5,
+	AD5770R_FILTER_11_2_KOHM,
+	AD5770R_FILTER_22_2_KOHM,
+	AD5770R_FILTER_44_4_KOHM,
+	AD5770R_FILTER_104_KOHM,
+};
+
+struct ad5770r_out_range {
+	u8	out_scale;
+	u8	out_range_mode;
+};
+
+/**
+ * struct ad5770R_state - driver instance specific data
+ * @spi:		spi_device
+ * @regmap:		regmap
+ * @vref_reg:		fixed regulator for reference configuration
+ * @gpio_reset:		gpio descriptor
+ * @output_mode:	array contains channels output ranges
+ * @vref:		reference value
+ * @ch_pwr_down:	powerdown flags
+ * @internal_ref:	internal reference flag
+ * @external_res:	external 2.5k resistor flag
+ * @transf_buf:		cache aligned buffer for spi read/write
+ */
+struct ad5770r_state {
+	struct spi_device		*spi;
+	struct regmap			*regmap;
+	struct regulator		*vref_reg;
+	struct gpio_desc		*gpio_reset;
+	struct ad5770r_out_range	output_mode[AD5770R_MAX_CHANNELS];
+	int				vref;
+	bool				ch_pwr_down[AD5770R_MAX_CHANNELS];
+	bool				internal_ref;
+	bool				external_res;
+	u8				transf_buf[2] ____cacheline_aligned;
+};
+
+static const struct regmap_config ad5770r_spi_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.read_flag_mask = BIT(7),
+};
+
+struct ad5770r_output_modes {
+	unsigned int ch;
+	u8 mode;
+	int min;
+	int max;
+};
+
+static struct ad5770r_output_modes ad5770r_rng_tbl[] = {
+	{ 0, AD5770R_CH0_0_300, 0, 300 },
+	{ 0, AD5770R_CH0_NEG_60_0, -60, 0 },
+	{ 0, AD5770R_CH0_NEG_60_300, -60, 300 },
+	{ 1, AD5770R_CH1_0_140_LOW_HEAD, 0, 140 },
+	{ 1, AD5770R_CH1_0_140_LOW_NOISE, 0, 140 },
+	{ 1, AD5770R_CH1_0_250, 0, 250 },
+	{ 2, AD5770R_CH_LOW_RANGE, 0, 55 },
+	{ 2, AD5770R_CH_HIGH_RANGE, 0, 150 },
+	{ 3, AD5770R_CH_LOW_RANGE, 0, 45 },
+	{ 3, AD5770R_CH_HIGH_RANGE, 0, 100 },
+	{ 4, AD5770R_CH_LOW_RANGE, 0, 45 },
+	{ 4, AD5770R_CH_HIGH_RANGE, 0, 100 },
+	{ 5, AD5770R_CH_LOW_RANGE, 0, 45 },
+	{ 5, AD5770R_CH_HIGH_RANGE, 0, 100 },
+};
+
+static const unsigned int ad5770r_filter_freqs[] = {
+	153, 357, 715, 1400, 2800, 262000,
+};
+
+static const unsigned int ad5770r_filter_reg_vals[] = {
+	AD5770R_FILTER_104_KOHM,
+	AD5770R_FILTER_44_4_KOHM,
+	AD5770R_FILTER_22_2_KOHM,
+	AD5770R_FILTER_11_2_KOHM,
+	AD5770R_FILTER_5_6_KOHM,
+	AD5770R_FILTER_60_OHM
+};
+
+static int ad5770r_set_output_mode(struct ad5770r_state *st,
+				   const struct ad5770r_out_range *out_mode,
+				   int channel)
+{
+	unsigned int regval;
+
+	regval = AD5770R_RANGE_OUTPUT_SCALING(out_mode->out_scale) |
+		 AD5770R_RANGE_MODE(out_mode->out_range_mode);
+
+	return regmap_write(st->regmap,
+			    AD5770R_OUTPUT_RANGE(channel), regval);
+}
+
+static int ad5770r_set_reference(struct ad5770r_state *st)
+{
+	unsigned int regval;
+
+	regval = AD5770R_REF_RESISTOR_SEL(st->external_res);
+
+	if (st->internal_ref) {
+		regval |= AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
+	} else {
+		switch (st->vref) {
+		case AD5770R_LOW_VREF_mV:
+			regval |= AD5770R_REF_SEL(AD5770R_EXT_1_25_V);
+			break;
+		case AD5770R_HIGH_VREF_mV:
+			regval |= AD5770R_REF_SEL(AD5770R_EXT_2_5_V);
+			break;
+		default:
+			regval = AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
+			break;
+		}
+	}
+
+	return regmap_write(st->regmap, AD5770R_REFERENCE, regval);
+}
+
+static int ad5770r_soft_reset(struct ad5770r_state *st)
+{
+	return regmap_write(st->regmap, ADI_SPI_IF_CONFIG_A,
+			    ADI_SPI_IF_SW_RESET_SEL(1));
+}
+
+static int ad5770r_reset(struct ad5770r_state *st)
+{
+	/* Perform software reset if no GPIO provided */
+	if (!st->gpio_reset)
+		return ad5770r_soft_reset(st);
+
+	gpiod_set_value_cansleep(st->gpio_reset, 0);
+	usleep_range(10, 20);
+	gpiod_set_value_cansleep(st->gpio_reset, 1);
+
+	/* data must not be written during reset timeframe */
+	usleep_range(100, 200);
+
+	return 0;
+}
+
+static int ad5770r_get_range(struct ad5770r_state *st,
+			     int ch, int *min, int *max)
+{
+	int i;
+	u8 tbl_ch, tbl_mode, out_range;
+
+	out_range = st->output_mode[ch].out_range_mode;
+
+	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
+		tbl_ch = ad5770r_rng_tbl[i].ch;
+		tbl_mode = ad5770r_rng_tbl[i].mode;
+		if (tbl_ch == ch && tbl_mode == out_range) {
+			*min = ad5770r_rng_tbl[i].min;
+			*max = ad5770r_rng_tbl[i].max;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int ad5770r_get_filter_freq(struct iio_dev *indio_dev,
+				   const struct iio_chan_spec *chan, int *freq)
+{
+	struct ad5770r_state *st = iio_priv(indio_dev);
+	int ret;
+	unsigned int regval, i;
+
+	ret = regmap_read(st->regmap,
+			  AD5770R_FILTER_RESISTOR(chan->channel), &regval);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_reg_vals); i++)
+		if (regval == ad5770r_filter_reg_vals[i])
+			break;
+	if (i == ARRAY_SIZE(ad5770r_filter_reg_vals))
+		return -EINVAL;
+
+	*freq = ad5770r_filter_freqs[i];
+
+	return IIO_VAL_INT;
+}
+
+static int ad5770r_set_filter_freq(struct iio_dev *indio_dev,
+				   const struct iio_chan_spec *chan,
+				   unsigned int freq)
+{
+	struct ad5770r_state *st = iio_priv(indio_dev);
+	unsigned int regval, i;
+
+	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_freqs); i++)
+		if (ad5770r_filter_freqs[i] >= freq)
+			break;
+	if (i == ARRAY_SIZE(ad5770r_filter_freqs))
+		return -EINVAL;
+
+	regval = ad5770r_filter_reg_vals[i];
+
+	return regmap_write(st->regmap, AD5770R_FILTER_RESISTOR(chan->channel),
+			    regval);
+}
+
+static int ad5770r_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long info)
+{
+	struct ad5770r_state *st = iio_priv(indio_dev);
+	int max, min, ret;
+	__le16 buf16;
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		ret = regmap_bulk_read(st->regmap,
+				       chan->address,
+				       st->transf_buf, 2);
+		if (ret)
+			return 0;
+
+		buf16 = st->transf_buf[0] + (st->transf_buf[1] << 8);
+		*val = le16_to_cpu(buf16) >> 2;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		ret = ad5770r_get_range(st, chan->channel, &min, &max);
+		if (ret < 0)
+			return ret;
+		*val = max - min;
+		/* There is no sign bit. (negative current is mapped from 0)
+		 * (sourced/sinked) current = raw * scale + offset
+		 * where offset in case of CH0 can be negative.
+		 */
+		*val2 = 14;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		return ad5770r_get_filter_freq(indio_dev, chan, val);
+	case IIO_CHAN_INFO_OFFSET:
+		ret = ad5770r_get_range(st, chan->channel, &min, &max);
+		if (ret < 0)
+			return ret;
+		*val = min;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad5770r_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long info)
+{
+	struct ad5770r_state *st = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		st->transf_buf[0] = ((u16)val >> 6);
+		st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;
+		return regmap_bulk_write(st->regmap, chan->address,
+					 st->transf_buf, 2);
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		return ad5770r_set_filter_freq(indio_dev, chan, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,
+				   struct iio_chan_spec const *chan,
+				   const int **vals, int *type, int *length,
+				   long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		*type = IIO_VAL_INT;
+		*vals = ad5770r_filter_freqs;
+		*length = ARRAY_SIZE(ad5770r_filter_freqs);
+		return IIO_AVAIL_LIST;
+	}
+
+	return -EINVAL;
+}
+
+static int ad5770r_reg_access(struct iio_dev *indio_dev,
+			      unsigned int reg,
+			      unsigned int writeval,
+			      unsigned int *readval)
+{
+	struct ad5770r_state *st = iio_priv(indio_dev);
+
+	if (readval)
+		return regmap_read(st->regmap, reg, readval);
+	else
+		return regmap_write(st->regmap, reg, writeval);
+}
+
+static const struct iio_info ad5770r_info = {
+	.read_raw = ad5770r_read_raw,
+	.write_raw = ad5770r_write_raw,
+	.read_avail = ad5770r_read_freq_avail,
+	.debugfs_reg_access = &ad5770r_reg_access,
+};
+
+static int ad5770r_store_output_range(struct ad5770r_state *st,
+				      int min, int max, int index)
+{
+	int i;
+
+	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
+		if (ad5770r_rng_tbl[i].ch != index)
+			continue;
+		if (ad5770r_rng_tbl[i].min != min ||
+		    ad5770r_rng_tbl[i].max != max)
+			continue;
+		st->output_mode[index].out_range_mode = ad5770r_rng_tbl[i].mode;
+
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t ad5770r_read_dac_powerdown(struct iio_dev *indio_dev,
+					  uintptr_t private,
+					  const struct iio_chan_spec *chan,
+					  char *buf)
+{
+	struct ad5770r_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n", st->ch_pwr_down[chan->channel]);
+}
+
+static ssize_t ad5770r_write_dac_powerdown(struct iio_dev *indio_dev,
+					   uintptr_t private,
+					   const struct iio_chan_spec *chan,
+					   const char *buf, size_t len)
+{
+	struct ad5770r_state *st = iio_priv(indio_dev);
+	unsigned int regval;
+	unsigned int mask;
+	bool readin;
+	int ret;
+
+	ret = kstrtobool(buf, &readin);
+	if (ret)
+		return ret;
+
+	readin = !readin;
+
+	regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);
+	if (chan->channel == 0 &&
+	    st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {
+		regval |= AD5770R_CFG_CH0_SINK_EN(readin);
+		mask = BIT(chan->channel) + BIT(7);
+	} else {
+		mask = BIT(chan->channel);
+	}
+	ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,
+				 regval);
+	if (ret)
+		return ret;
+
+	regval = AD5770R_CH_SET(readin, chan->channel);
+	ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,
+				 BIT(chan->channel), regval);
+	if (ret)
+		return ret;
+
+	st->ch_pwr_down[chan->channel] = !readin;
+
+	return len;
+}
+
+static const struct iio_chan_spec_ext_info ad5770r_ext_info[] = {
+	{
+		.name = "powerdown",
+		.read = ad5770r_read_dac_powerdown,
+		.write = ad5770r_write_dac_powerdown,
+		.shared = IIO_SEPARATE,
+	},
+	{ }
+};
+
+#define AD5770R_IDAC_CHANNEL(index, reg) {				\
+	.type = IIO_CURRENT,						\
+	.address = reg,							\
+	.indexed = 1,							\
+	.channel = index,						\
+	.output = 1,							\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
+		BIT(IIO_CHAN_INFO_SCALE) |				\
+		BIT(IIO_CHAN_INFO_OFFSET) |				\
+		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
+	.info_mask_shared_by_type_available =				\
+		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
+	.ext_info = ad5770r_ext_info,					\
+}
+
+static const struct iio_chan_spec ad5770r_channels[] = {
+	AD5770R_IDAC_CHANNEL(0, AD5770R_DAC_MSB(0)),
+	AD5770R_IDAC_CHANNEL(1, AD5770R_DAC_MSB(1)),
+	AD5770R_IDAC_CHANNEL(2, AD5770R_DAC_MSB(2)),
+	AD5770R_IDAC_CHANNEL(3, AD5770R_DAC_MSB(3)),
+	AD5770R_IDAC_CHANNEL(4, AD5770R_DAC_MSB(4)),
+	AD5770R_IDAC_CHANNEL(5, AD5770R_DAC_MSB(5)),
+};
+
+static int ad5770r_channel_config(struct ad5770r_state *st)
+{
+	int ret, tmp[2], min, max;
+	unsigned int num;
+	struct fwnode_handle *child;
+
+	num = device_get_child_node_count(&st->spi->dev);
+	if (num != AD5770R_MAX_CHANNELS)
+		return -EINVAL;
+
+	device_for_each_child_node(&st->spi->dev, child) {
+		ret = fwnode_property_read_u32(child, "num", &num);
+		if (ret)
+			return ret;
+		if (num > AD5770R_MAX_CHANNELS)
+			return -EINVAL;
+
+		ret = fwnode_property_read_u32_array(child,
+						     "adi,range-microamp",
+						     tmp, 2);
+		if (ret)
+			return ret;
+
+		min = tmp[0] / 1000;
+		max = tmp[1] / 1000;
+		ret = ad5770r_store_output_range(st, min, max, num);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+static int ad5770r_init(struct ad5770r_state *st)
+{
+	int ret, i;
+
+	st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
+						 GPIOD_OUT_HIGH);
+	if (IS_ERR(st->gpio_reset))
+		return PTR_ERR(st->gpio_reset);
+
+	/* Perform a reset */
+	ret = ad5770r_reset(st);
+	if (ret)
+		return ret;
+
+	/* Set output range */
+	ret = ad5770r_channel_config(st);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < AD5770R_MAX_CHANNELS; i++) {
+		ret = ad5770r_set_output_mode(st,  &st->output_mode[i], i);
+		if (ret)
+			return ret;
+	}
+
+	st->external_res = fwnode_property_read_bool(st->spi->dev.fwnode,
+						     "adi,external-resistor");
+
+	ret = ad5770r_set_reference(st);
+	if (ret)
+		return ret;
+
+	/* Set outputs off */
+	ret = regmap_write(st->regmap, AD5770R_CHANNEL_CONFIG, 0x00);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(st->regmap, AD5770R_CH_ENABLE, 0x00);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < AD5770R_MAX_CHANNELS; i++)
+		st->ch_pwr_down[i] = true;
+
+	return ret;
+}
+
+static void ad5770r_disable_regulator(void *data)
+{
+	struct ad5770r_state *st = data;
+
+	regulator_disable(st->vref_reg);
+}
+
+static int ad5770r_probe(struct spi_device *spi)
+{
+	struct ad5770r_state *st;
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	spi_set_drvdata(spi, indio_dev);
+
+	st->spi = spi;
+
+	regmap = devm_regmap_init_spi(spi, &ad5770r_spi_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
+			PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+	st->regmap = regmap;
+
+	st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
+	if (!IS_ERR(st->vref_reg)) {
+		ret = regulator_enable(st->vref_reg);
+		if (ret) {
+			dev_err(&spi->dev,
+				"Failed to enable vref regulators: %d\n", ret);
+			return ret;
+		}
+
+		ret = devm_add_action_or_reset(&spi->dev,
+					       ad5770r_disable_regulator,
+					       st);
+		if (ret < 0)
+			return ret;
+
+		ret = regulator_get_voltage(st->vref_reg);
+		if (ret < 0)
+			return ret;
+
+		st->vref = ret / 1000;
+	} else {
+		if (PTR_ERR(st->vref_reg) == -ENODEV) {
+			st->vref = AD5770R_LOW_VREF_mV;
+			st->internal_ref = true;
+		} else {
+			return PTR_ERR(st->vref_reg);
+		}
+	}
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->info = &ad5770r_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = ad5770r_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ad5770r_channels);
+
+	ret = ad5770r_init(st);
+	if (ret < 0) {
+		dev_err(&spi->dev, "AD5770R init failed\n");
+		return ret;
+	}
+
+	return devm_iio_device_register(&st->spi->dev, indio_dev);
+}
+
+static const struct of_device_id ad5770r_of_id[] = {
+	{ .compatible = "adi,ad5770r", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ad5770r_of_id);
+
+static const struct spi_device_id ad5770r_id[] = {
+	{ "ad5770r", 0 },
+	{},
+};
+MODULE_DEVICE_TABLE(spi, ad5770r_id);
+
+static struct spi_driver ad5770r_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = ad5770r_of_id,
+	},
+	.probe = ad5770r_probe,
+	.id_table = ad5770r_id,
+};
+
+module_spi_driver(ad5770r_driver);
+
+MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD5770R IDAC");
+MODULE_LICENSE("GPL v2");
-- 
2.20.1

Re: [PATCH v4 1/2] iio: dac: ad5770r: Add AD5770R support

[Jonathan Cameron]

On Tue, 18 Feb 2020 14:10:30 +0200
Alexandru Tachici <alexandru.tachici@analog.com> wrote:

> The AD5770R is a 6-channel, 14-bit resolution, low noise, programmable
> current output digital-to-analog converter (DAC) for photonics control
> applications.
> 
> It contains five 14-bit resolution current sourcing DAC channels and one
> 14-bit resolution current sourcing/sinking DAC channel.
> 
> Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
> Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
The switch to a dma safe buffer has gone a bit wrong.  See inline.

I've fixed up whilst applying as described.  Please check the result.

Applied to the togreg branch of iio.git and pushed out as testing.

Thanks,

Jonathan


> ---
>  drivers/iio/dac/Kconfig   |  10 +
>  drivers/iio/dac/Makefile  |   1 +
>  drivers/iio/dac/ad5770r.c | 695 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 706 insertions(+)
>  create mode 100644 drivers/iio/dac/ad5770r.c
> 
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index 979070196da9..c74f2151ee42 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -208,6 +208,16 @@ config AD5764
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called ad5764.
>  
> +config AD5770R
> +	tristate "Analog Devices AD5770R IDAC driver"
> +	depends on SPI_MASTER
> +	help
> +	  Say yes here to build support for Analog Devices AD5770R Digital to
> +	  Analog Converter.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called ad5770r.
> +
>  config AD5791
>  	tristate "Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC SPI driver"
>  	depends on SPI
> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
> index 1369fa1d2f0e..2fc481167724 100644
> --- a/drivers/iio/dac/Makefile
> +++ b/drivers/iio/dac/Makefile
> @@ -19,6 +19,7 @@ obj-$(CONFIG_AD5755) += ad5755.o
>  obj-$(CONFIG_AD5755) += ad5758.o
>  obj-$(CONFIG_AD5761) += ad5761.o
>  obj-$(CONFIG_AD5764) += ad5764.o
> +obj-$(CONFIG_AD5770R) += ad5770r.o
>  obj-$(CONFIG_AD5791) += ad5791.o
>  obj-$(CONFIG_AD5686) += ad5686.o
>  obj-$(CONFIG_AD5686_SPI) += ad5686-spi.o
> diff --git a/drivers/iio/dac/ad5770r.c b/drivers/iio/dac/ad5770r.c
> new file mode 100644
> index 000000000000..0ca2f69644ea
> --- /dev/null
> +++ b/drivers/iio/dac/ad5770r.c
> @@ -0,0 +1,695 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AD5770R Digital to analog converters driver
> + *
> + * Copyright 2018 Analog Devices Inc.
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/spi/spi.h>
> +
> +#define ADI_SPI_IF_CONFIG_A		0x00
> +#define ADI_SPI_IF_CONFIG_B		0x01
> +#define ADI_SPI_IF_DEVICE_CONFIG	0x02
> +#define ADI_SPI_IF_CHIP_TYPE		0x03
> +#define ADI_SPI_IF_PRODUCT_ID_L		0x04
> +#define ADI_SPI_IF_PRODUCT_ID_H		0x05
> +#define ADI_SPI_IF_CHIP_GRADE		0x06
> +#define ADI_SPI_IF_SCRACTH_PAD		0x0A
> +#define ADI_SPI_IF_SPI_REVISION		0x0B
> +#define ADI_SPI_IF_SPI_VENDOR_L		0x0C
> +#define ADI_SPI_IF_SPI_VENDOR_H		0x0D
> +#define ADI_SPI_IF_SPI_STREAM_MODE	0x0E
> +#define ADI_SPI_IF_CONFIG_C		0x10
> +#define ADI_SPI_IF_STATUS_A		0x11
> +
> +/* ADI_SPI_IF_CONFIG_A */
> +#define ADI_SPI_IF_SW_RESET_MSK		(BIT(0) | BIT(7))
> +#define ADI_SPI_IF_SW_RESET_SEL(x)	((x) & ADI_SPI_IF_SW_RESET_MSK)
> +#define ADI_SPI_IF_ADDR_ASC_MSK		(BIT(2) | BIT(5))
> +#define ADI_SPI_IF_ADDR_ASC_SEL(x)	(((x) << 2) & ADI_SPI_IF_ADDR_ASC_MSK)
> +
> +/* ADI_SPI_IF_CONFIG_B */
> +#define ADI_SPI_IF_SINGLE_INS_MSK	BIT(7)
> +#define ADI_SPI_IF_SINGLE_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
> +#define ADI_SPI_IF_SHORT_INS_MSK	BIT(7)
> +#define ADI_SPI_IF_SHORT_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
> +
> +/* ADI_SPI_IF_CONFIG_C */
> +#define ADI_SPI_IF_STRICT_REG_MSK	BIT(5)
> +#define ADI_SPI_IF_STRICT_REG_GET(x)	FIELD_GET(ADI_SPI_IF_STRICT_REG_MSK, x)
> +
> +/* AD5770R configuration registers */
> +#define AD5770R_CHANNEL_CONFIG		0x14
> +#define AD5770R_OUTPUT_RANGE(ch)	(0x15 + (ch))
> +#define AD5770R_FILTER_RESISTOR(ch)	(0x1D + (ch))
> +#define AD5770R_REFERENCE		0x1B
> +#define AD5770R_DAC_LSB(ch)		(0x26 + 2 * (ch))
> +#define AD5770R_DAC_MSB(ch)		(0x27 + 2 * (ch))
> +#define AD5770R_CH_SELECT		0x34
> +#define AD5770R_CH_ENABLE		0x44
> +
> +/* AD5770R_CHANNEL_CONFIG */
> +#define AD5770R_CFG_CH0_SINK_EN(x)		(((x) & 0x1) << 7)
> +#define AD5770R_CFG_SHUTDOWN_B(x, ch)		(((x) & 0x1) << (ch))
> +
> +/* AD5770R_OUTPUT_RANGE */
> +#define AD5770R_RANGE_OUTPUT_SCALING(x)		(((x) & GENMASK(5, 0)) << 2)
> +#define AD5770R_RANGE_MODE(x)			((x) & GENMASK(1, 0))
> +
> +/* AD5770R_REFERENCE */
> +#define AD5770R_REF_RESISTOR_SEL(x)		(((x) & 0x1) << 2)
> +#define AD5770R_REF_SEL(x)			((x) & GENMASK(1, 0))
> +
> +/* AD5770R_CH_ENABLE */
> +#define AD5770R_CH_SET(x, ch)		(((x) & 0x1) << (ch))
> +
> +#define AD5770R_MAX_CHANNELS	6
> +#define AD5770R_MAX_CH_MODES	14
> +#define AD5770R_LOW_VREF_mV	1250
> +#define AD5770R_HIGH_VREF_mV	2500
> +
> +enum ad5770r_ch0_modes {
> +	AD5770R_CH0_0_300 = 0,
> +	AD5770R_CH0_NEG_60_0,
> +	AD5770R_CH0_NEG_60_300
> +};
> +
> +enum ad5770r_ch1_modes {
> +	AD5770R_CH1_0_140_LOW_HEAD = 1,
> +	AD5770R_CH1_0_140_LOW_NOISE,
> +	AD5770R_CH1_0_250
> +};
> +
> +enum ad5770r_ch2_5_modes {
> +	AD5770R_CH_LOW_RANGE = 0,
> +	AD5770R_CH_HIGH_RANGE
> +};
> +
> +enum ad5770r_ref_v {
> +	AD5770R_EXT_2_5_V = 0,
> +	AD5770R_INT_1_25_V_OUT_ON,
> +	AD5770R_EXT_1_25_V,
> +	AD5770R_INT_1_25_V_OUT_OFF
> +};
> +
> +enum ad5770r_output_filter_resistor {
> +	AD5770R_FILTER_60_OHM = 0x0,
> +	AD5770R_FILTER_5_6_KOHM = 0x5,
> +	AD5770R_FILTER_11_2_KOHM,
> +	AD5770R_FILTER_22_2_KOHM,
> +	AD5770R_FILTER_44_4_KOHM,
> +	AD5770R_FILTER_104_KOHM,
> +};
> +
> +struct ad5770r_out_range {
> +	u8	out_scale;
> +	u8	out_range_mode;
> +};
> +
> +/**
> + * struct ad5770R_state - driver instance specific data
> + * @spi:		spi_device
> + * @regmap:		regmap
> + * @vref_reg:		fixed regulator for reference configuration
> + * @gpio_reset:		gpio descriptor
> + * @output_mode:	array contains channels output ranges
> + * @vref:		reference value
> + * @ch_pwr_down:	powerdown flags
> + * @internal_ref:	internal reference flag
> + * @external_res:	external 2.5k resistor flag
> + * @transf_buf:		cache aligned buffer for spi read/write
> + */
> +struct ad5770r_state {
> +	struct spi_device		*spi;
> +	struct regmap			*regmap;
> +	struct regulator		*vref_reg;
> +	struct gpio_desc		*gpio_reset;
> +	struct ad5770r_out_range	output_mode[AD5770R_MAX_CHANNELS];
> +	int				vref;
> +	bool				ch_pwr_down[AD5770R_MAX_CHANNELS];
> +	bool				internal_ref;
> +	bool				external_res;
> +	u8				transf_buf[2] ____cacheline_aligned;
> +};
> +
> +static const struct regmap_config ad5770r_spi_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.read_flag_mask = BIT(7),
> +};
> +
> +struct ad5770r_output_modes {
> +	unsigned int ch;
> +	u8 mode;
> +	int min;
> +	int max;
> +};
> +
> +static struct ad5770r_output_modes ad5770r_rng_tbl[] = {
> +	{ 0, AD5770R_CH0_0_300, 0, 300 },
> +	{ 0, AD5770R_CH0_NEG_60_0, -60, 0 },
> +	{ 0, AD5770R_CH0_NEG_60_300, -60, 300 },
> +	{ 1, AD5770R_CH1_0_140_LOW_HEAD, 0, 140 },
> +	{ 1, AD5770R_CH1_0_140_LOW_NOISE, 0, 140 },
> +	{ 1, AD5770R_CH1_0_250, 0, 250 },
> +	{ 2, AD5770R_CH_LOW_RANGE, 0, 55 },
> +	{ 2, AD5770R_CH_HIGH_RANGE, 0, 150 },
> +	{ 3, AD5770R_CH_LOW_RANGE, 0, 45 },
> +	{ 3, AD5770R_CH_HIGH_RANGE, 0, 100 },
> +	{ 4, AD5770R_CH_LOW_RANGE, 0, 45 },
> +	{ 4, AD5770R_CH_HIGH_RANGE, 0, 100 },
> +	{ 5, AD5770R_CH_LOW_RANGE, 0, 45 },
> +	{ 5, AD5770R_CH_HIGH_RANGE, 0, 100 },
> +};
> +
> +static const unsigned int ad5770r_filter_freqs[] = {
> +	153, 357, 715, 1400, 2800, 262000,
> +};
> +
> +static const unsigned int ad5770r_filter_reg_vals[] = {
> +	AD5770R_FILTER_104_KOHM,
> +	AD5770R_FILTER_44_4_KOHM,
> +	AD5770R_FILTER_22_2_KOHM,
> +	AD5770R_FILTER_11_2_KOHM,
> +	AD5770R_FILTER_5_6_KOHM,
> +	AD5770R_FILTER_60_OHM
> +};
> +
> +static int ad5770r_set_output_mode(struct ad5770r_state *st,
> +				   const struct ad5770r_out_range *out_mode,
> +				   int channel)
> +{
> +	unsigned int regval;
> +
> +	regval = AD5770R_RANGE_OUTPUT_SCALING(out_mode->out_scale) |
> +		 AD5770R_RANGE_MODE(out_mode->out_range_mode);
> +
> +	return regmap_write(st->regmap,
> +			    AD5770R_OUTPUT_RANGE(channel), regval);
> +}
> +
> +static int ad5770r_set_reference(struct ad5770r_state *st)
> +{
> +	unsigned int regval;
> +
> +	regval = AD5770R_REF_RESISTOR_SEL(st->external_res);
> +
> +	if (st->internal_ref) {
> +		regval |= AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
> +	} else {
> +		switch (st->vref) {
> +		case AD5770R_LOW_VREF_mV:
> +			regval |= AD5770R_REF_SEL(AD5770R_EXT_1_25_V);
> +			break;
> +		case AD5770R_HIGH_VREF_mV:
> +			regval |= AD5770R_REF_SEL(AD5770R_EXT_2_5_V);
> +			break;
> +		default:
> +			regval = AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
> +			break;
> +		}
> +	}
> +
> +	return regmap_write(st->regmap, AD5770R_REFERENCE, regval);
> +}
> +
> +static int ad5770r_soft_reset(struct ad5770r_state *st)
> +{
> +	return regmap_write(st->regmap, ADI_SPI_IF_CONFIG_A,
> +			    ADI_SPI_IF_SW_RESET_SEL(1));
> +}
> +
> +static int ad5770r_reset(struct ad5770r_state *st)
> +{
> +	/* Perform software reset if no GPIO provided */
> +	if (!st->gpio_reset)
> +		return ad5770r_soft_reset(st);
> +
> +	gpiod_set_value_cansleep(st->gpio_reset, 0);
> +	usleep_range(10, 20);
> +	gpiod_set_value_cansleep(st->gpio_reset, 1);
> +
> +	/* data must not be written during reset timeframe */
> +	usleep_range(100, 200);
> +
> +	return 0;
> +}
> +
> +static int ad5770r_get_range(struct ad5770r_state *st,
> +			     int ch, int *min, int *max)
> +{
> +	int i;
> +	u8 tbl_ch, tbl_mode, out_range;
> +
> +	out_range = st->output_mode[ch].out_range_mode;
> +
> +	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
> +		tbl_ch = ad5770r_rng_tbl[i].ch;
> +		tbl_mode = ad5770r_rng_tbl[i].mode;
> +		if (tbl_ch == ch && tbl_mode == out_range) {
> +			*min = ad5770r_rng_tbl[i].min;
> +			*max = ad5770r_rng_tbl[i].max;
> +			return 0;
> +		}
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int ad5770r_get_filter_freq(struct iio_dev *indio_dev,
> +				   const struct iio_chan_spec *chan, int *freq)
> +{
> +	struct ad5770r_state *st = iio_priv(indio_dev);
> +	int ret;
> +	unsigned int regval, i;
> +
> +	ret = regmap_read(st->regmap,
> +			  AD5770R_FILTER_RESISTOR(chan->channel), &regval);
> +	if (ret < 0)
> +		return ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_reg_vals); i++)
> +		if (regval == ad5770r_filter_reg_vals[i])
> +			break;
> +	if (i == ARRAY_SIZE(ad5770r_filter_reg_vals))
> +		return -EINVAL;
> +
> +	*freq = ad5770r_filter_freqs[i];
> +
> +	return IIO_VAL_INT;
> +}
> +
> +static int ad5770r_set_filter_freq(struct iio_dev *indio_dev,
> +				   const struct iio_chan_spec *chan,
> +				   unsigned int freq)
> +{
> +	struct ad5770r_state *st = iio_priv(indio_dev);
> +	unsigned int regval, i;
> +
> +	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_freqs); i++)
> +		if (ad5770r_filter_freqs[i] >= freq)
> +			break;
> +	if (i == ARRAY_SIZE(ad5770r_filter_freqs))
> +		return -EINVAL;
> +
> +	regval = ad5770r_filter_reg_vals[i];
> +
> +	return regmap_write(st->regmap, AD5770R_FILTER_RESISTOR(chan->channel),
> +			    regval);
> +}
> +
> +static int ad5770r_read_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int *val, int *val2, long info)
> +{
> +	struct ad5770r_state *st = iio_priv(indio_dev);
> +	int max, min, ret;
> +	__le16 buf16;
> +
> +	switch (info) {
> +	case IIO_CHAN_INFO_RAW:
> +		ret = regmap_bulk_read(st->regmap,
> +				       chan->address,
> +				       st->transf_buf, 2);
In this case, you are reading into a pair of bytes...

> +		if (ret)
> +			return 0;
> +
> +		buf16 = st->transf_buf[0] + (st->transf_buf[1] << 8);

and you combine them by bad.  The result is what endian type the cpu
has.

> +		*val = le16_to_cpu(buf16) >> 2;
So we can drop the le16_to_cpu here + change the type above.

I've fixed up.
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		ret = ad5770r_get_range(st, chan->channel, &min, &max);
> +		if (ret < 0)
> +			return ret;
> +		*val = max - min;
> +		/* There is no sign bit. (negative current is mapped from 0)
> +		 * (sourced/sinked) current = raw * scale + offset
> +		 * where offset in case of CH0 can be negative.
> +		 */
> +		*val2 = 14;
> +		return IIO_VAL_FRACTIONAL_LOG2;
> +	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> +		return ad5770r_get_filter_freq(indio_dev, chan, val);
> +	case IIO_CHAN_INFO_OFFSET:
> +		ret = ad5770r_get_range(st, chan->channel, &min, &max);
> +		if (ret < 0)
> +			return ret;
> +		*val = min;
> +		return IIO_VAL_INT;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int ad5770r_write_raw(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan,
> +			     int val, int val2, long info)
> +{
> +	struct ad5770r_state *st = iio_priv(indio_dev);
> +
> +	switch (info) {
> +	case IIO_CHAN_INFO_RAW:
> +		st->transf_buf[0] = ((u16)val >> 6);
> +		st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;
> +		return regmap_bulk_write(st->regmap, chan->address,
> +					 st->transf_buf, 2);
> +	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> +		return ad5770r_set_filter_freq(indio_dev, chan, val);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,
> +				   struct iio_chan_spec const *chan,
> +				   const int **vals, int *type, int *length,
> +				   long mask)
> +{
> +	switch (mask) {
> +	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> +		*type = IIO_VAL_INT;
> +		*vals = ad5770r_filter_freqs;
> +		*length = ARRAY_SIZE(ad5770r_filter_freqs);
> +		return IIO_AVAIL_LIST;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int ad5770r_reg_access(struct iio_dev *indio_dev,
> +			      unsigned int reg,
> +			      unsigned int writeval,
> +			      unsigned int *readval)
> +{
> +	struct ad5770r_state *st = iio_priv(indio_dev);
> +
> +	if (readval)
> +		return regmap_read(st->regmap, reg, readval);
> +	else
> +		return regmap_write(st->regmap, reg, writeval);
> +}
> +
> +static const struct iio_info ad5770r_info = {
> +	.read_raw = ad5770r_read_raw,
> +	.write_raw = ad5770r_write_raw,
> +	.read_avail = ad5770r_read_freq_avail,
> +	.debugfs_reg_access = &ad5770r_reg_access,
> +};
> +
> +static int ad5770r_store_output_range(struct ad5770r_state *st,
> +				      int min, int max, int index)
> +{
> +	int i;
> +
> +	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
> +		if (ad5770r_rng_tbl[i].ch != index)
> +			continue;
> +		if (ad5770r_rng_tbl[i].min != min ||
> +		    ad5770r_rng_tbl[i].max != max)
> +			continue;
> +		st->output_mode[index].out_range_mode = ad5770r_rng_tbl[i].mode;
> +
> +		return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static ssize_t ad5770r_read_dac_powerdown(struct iio_dev *indio_dev,
> +					  uintptr_t private,
> +					  const struct iio_chan_spec *chan,
> +					  char *buf)
> +{
> +	struct ad5770r_state *st = iio_priv(indio_dev);
> +
> +	return sprintf(buf, "%d\n", st->ch_pwr_down[chan->channel]);
> +}
> +
> +static ssize_t ad5770r_write_dac_powerdown(struct iio_dev *indio_dev,
> +					   uintptr_t private,
> +					   const struct iio_chan_spec *chan,
> +					   const char *buf, size_t len)
> +{
> +	struct ad5770r_state *st = iio_priv(indio_dev);
> +	unsigned int regval;
> +	unsigned int mask;
> +	bool readin;
> +	int ret;
> +
> +	ret = kstrtobool(buf, &readin);
> +	if (ret)
> +		return ret;
> +
> +	readin = !readin;
> +
> +	regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);
> +	if (chan->channel == 0 &&
> +	    st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {
> +		regval |= AD5770R_CFG_CH0_SINK_EN(readin);
> +		mask = BIT(chan->channel) + BIT(7);
> +	} else {
> +		mask = BIT(chan->channel);
> +	}
> +	ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,
> +				 regval);
> +	if (ret)
> +		return ret;
> +
> +	regval = AD5770R_CH_SET(readin, chan->channel);
> +	ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,
> +				 BIT(chan->channel), regval);
> +	if (ret)
> +		return ret;
> +
> +	st->ch_pwr_down[chan->channel] = !readin;
> +
> +	return len;
> +}
> +
> +static const struct iio_chan_spec_ext_info ad5770r_ext_info[] = {
> +	{
> +		.name = "powerdown",
> +		.read = ad5770r_read_dac_powerdown,
> +		.write = ad5770r_write_dac_powerdown,
> +		.shared = IIO_SEPARATE,
> +	},
> +	{ }
> +};
> +
> +#define AD5770R_IDAC_CHANNEL(index, reg) {				\
> +	.type = IIO_CURRENT,						\
> +	.address = reg,							\
> +	.indexed = 1,							\
> +	.channel = index,						\
> +	.output = 1,							\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
> +		BIT(IIO_CHAN_INFO_SCALE) |				\
> +		BIT(IIO_CHAN_INFO_OFFSET) |				\
> +		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
> +	.info_mask_shared_by_type_available =				\
> +		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
> +	.ext_info = ad5770r_ext_info,					\
> +}
> +
> +static const struct iio_chan_spec ad5770r_channels[] = {
> +	AD5770R_IDAC_CHANNEL(0, AD5770R_DAC_MSB(0)),
> +	AD5770R_IDAC_CHANNEL(1, AD5770R_DAC_MSB(1)),
> +	AD5770R_IDAC_CHANNEL(2, AD5770R_DAC_MSB(2)),
> +	AD5770R_IDAC_CHANNEL(3, AD5770R_DAC_MSB(3)),
> +	AD5770R_IDAC_CHANNEL(4, AD5770R_DAC_MSB(4)),
> +	AD5770R_IDAC_CHANNEL(5, AD5770R_DAC_MSB(5)),
> +};
> +
> +static int ad5770r_channel_config(struct ad5770r_state *st)
> +{
> +	int ret, tmp[2], min, max;
> +	unsigned int num;
> +	struct fwnode_handle *child;
> +
> +	num = device_get_child_node_count(&st->spi->dev);
> +	if (num != AD5770R_MAX_CHANNELS)
> +		return -EINVAL;
> +
> +	device_for_each_child_node(&st->spi->dev, child) {
> +		ret = fwnode_property_read_u32(child, "num", &num);
> +		if (ret)
> +			return ret;
> +		if (num > AD5770R_MAX_CHANNELS)
> +			return -EINVAL;
> +
> +		ret = fwnode_property_read_u32_array(child,
> +						     "adi,range-microamp",
> +						     tmp, 2);
> +		if (ret)
> +			return ret;
> +
> +		min = tmp[0] / 1000;
> +		max = tmp[1] / 1000;
> +		ret = ad5770r_store_output_range(st, min, max, num);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return ret;
> +}
> +
> +static int ad5770r_init(struct ad5770r_state *st)
> +{
> +	int ret, i;
> +
> +	st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
> +						 GPIOD_OUT_HIGH);
> +	if (IS_ERR(st->gpio_reset))
> +		return PTR_ERR(st->gpio_reset);
> +
> +	/* Perform a reset */
> +	ret = ad5770r_reset(st);
> +	if (ret)
> +		return ret;
> +
> +	/* Set output range */
> +	ret = ad5770r_channel_config(st);
> +	if (ret)
> +		return ret;
> +
> +	for (i = 0; i < AD5770R_MAX_CHANNELS; i++) {
> +		ret = ad5770r_set_output_mode(st,  &st->output_mode[i], i);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	st->external_res = fwnode_property_read_bool(st->spi->dev.fwnode,
> +						     "adi,external-resistor");
> +
> +	ret = ad5770r_set_reference(st);
> +	if (ret)
> +		return ret;
> +
> +	/* Set outputs off */
> +	ret = regmap_write(st->regmap, AD5770R_CHANNEL_CONFIG, 0x00);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_write(st->regmap, AD5770R_CH_ENABLE, 0x00);
> +	if (ret)
> +		return ret;
> +
> +	for (i = 0; i < AD5770R_MAX_CHANNELS; i++)
> +		st->ch_pwr_down[i] = true;
> +
> +	return ret;
> +}
> +
> +static void ad5770r_disable_regulator(void *data)
> +{
> +	struct ad5770r_state *st = data;
> +
> +	regulator_disable(st->vref_reg);
> +}
> +
> +static int ad5770r_probe(struct spi_device *spi)
> +{
> +	struct ad5770r_state *st;
> +	struct iio_dev *indio_dev;
> +	struct regmap *regmap;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	st = iio_priv(indio_dev);
> +	spi_set_drvdata(spi, indio_dev);
> +
> +	st->spi = spi;
> +
> +	regmap = devm_regmap_init_spi(spi, &ad5770r_spi_regmap_config);
> +	if (IS_ERR(regmap)) {
> +		dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
> +			PTR_ERR(regmap));
> +		return PTR_ERR(regmap);
> +	}
> +	st->regmap = regmap;
> +
> +	st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
> +	if (!IS_ERR(st->vref_reg)) {
> +		ret = regulator_enable(st->vref_reg);
> +		if (ret) {
> +			dev_err(&spi->dev,
> +				"Failed to enable vref regulators: %d\n", ret);
> +			return ret;
> +		}
> +
> +		ret = devm_add_action_or_reset(&spi->dev,
> +					       ad5770r_disable_regulator,
> +					       st);
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = regulator_get_voltage(st->vref_reg);
> +		if (ret < 0)
> +			return ret;
> +
> +		st->vref = ret / 1000;
> +	} else {
> +		if (PTR_ERR(st->vref_reg) == -ENODEV) {
> +			st->vref = AD5770R_LOW_VREF_mV;
> +			st->internal_ref = true;
> +		} else {
> +			return PTR_ERR(st->vref_reg);
> +		}
> +	}
> +
> +	indio_dev->dev.parent = &spi->dev;
> +	indio_dev->name = spi_get_device_id(spi)->name;
> +	indio_dev->info = &ad5770r_info;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = ad5770r_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(ad5770r_channels);
> +
> +	ret = ad5770r_init(st);
> +	if (ret < 0) {
> +		dev_err(&spi->dev, "AD5770R init failed\n");
> +		return ret;
> +	}
> +
> +	return devm_iio_device_register(&st->spi->dev, indio_dev);
> +}
> +
> +static const struct of_device_id ad5770r_of_id[] = {
> +	{ .compatible = "adi,ad5770r", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, ad5770r_of_id);
> +
> +static const struct spi_device_id ad5770r_id[] = {
> +	{ "ad5770r", 0 },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(spi, ad5770r_id);
> +
> +static struct spi_driver ad5770r_driver = {
> +	.driver = {
> +		.name = KBUILD_MODNAME,
> +		.of_match_table = ad5770r_of_id,
> +	},
> +	.probe = ad5770r_probe,
> +	.id_table = ad5770r_id,
> +};
> +
> +module_spi_driver(ad5770r_driver);
> +
> +MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
> +MODULE_DESCRIPTION("Analog Devices AD5770R IDAC");
> +MODULE_LICENSE("GPL v2");

Re: [PATCH v4 1/2] iio: dac: ad5770r: Add AD5770R support

[Andy Shevchenko]

On Tue, Feb 18, 2020 at 02:10:30PM +0200, Alexandru Tachici wrote:
> The AD5770R is a 6-channel, 14-bit resolution, low noise, programmable
> current output digital-to-analog converter (DAC) for photonics control
> applications.
> 
> It contains five 14-bit resolution current sourcing DAC channels and one
> 14-bit resolution current sourcing/sinking DAC channel.

...

> +#define AD5770R_CFG_CH0_SINK_EN(x)		(((x) & 0x1) << 7)
> +#define AD5770R_CFG_SHUTDOWN_B(x, ch)		(((x) & 0x1) << (ch))

BIT(0) ?

> +#define AD5770R_REF_RESISTOR_SEL(x)		(((x) & 0x1) << 2)

Ditto.

> +#define AD5770R_CH_SET(x, ch)		(((x) & 0x1) << (ch))

Ditto.

...

> +enum ad5770r_ch0_modes {
> +	AD5770R_CH0_0_300 = 0,
> +	AD5770R_CH0_NEG_60_0,
> +	AD5770R_CH0_NEG_60_300
> +};
> +
> +enum ad5770r_ch1_modes {
> +	AD5770R_CH1_0_140_LOW_HEAD = 1,
> +	AD5770R_CH1_0_140_LOW_NOISE,
> +	AD5770R_CH1_0_250
> +};
> +
> +enum ad5770r_ch2_5_modes {
> +	AD5770R_CH_LOW_RANGE = 0,
> +	AD5770R_CH_HIGH_RANGE
> +};
> +
> +enum ad5770r_ref_v {
> +	AD5770R_EXT_2_5_V = 0,
> +	AD5770R_INT_1_25_V_OUT_ON,
> +	AD5770R_EXT_1_25_V,
> +	AD5770R_INT_1_25_V_OUT_OFF
> +};
> +
> +enum ad5770r_output_filter_resistor {
> +	AD5770R_FILTER_60_OHM = 0x0,
> +	AD5770R_FILTER_5_6_KOHM = 0x5,
> +	AD5770R_FILTER_11_2_KOHM,
> +	AD5770R_FILTER_22_2_KOHM,
> +	AD5770R_FILTER_44_4_KOHM,

> +	AD5770R_FILTER_104_KOHM,

It would be nice to go consistent about last entry in enums. Are they
terminators? For me it doesn't look like it (new revision of hardware
always can use extended lists of modes, etc).

So, I think leaving comma for all above is a right thing to do.

> +};

...

> +static const unsigned int ad5770r_filter_reg_vals[] = {
> +	AD5770R_FILTER_104_KOHM,
> +	AD5770R_FILTER_44_4_KOHM,
> +	AD5770R_FILTER_22_2_KOHM,
> +	AD5770R_FILTER_11_2_KOHM,
> +	AD5770R_FILTER_5_6_KOHM,
> +	AD5770R_FILTER_60_OHM
> +};

Ditto.

...

> +	return regmap_write(st->regmap,
> +			    AD5770R_OUTPUT_RANGE(channel), regval);

It fits one line (even has room for one character more)
Perhaps you may consider to amend settings of your text editor?
Please fix all similar places in all of your patches.

...

> +static int ad5770r_reset(struct ad5770r_state *st)
> +{
> +	/* Perform software reset if no GPIO provided */
> +	if (!st->gpio_reset)
> +		return ad5770r_soft_reset(st);


Perhaps split this to _reset_gpio() and do

	if (gpio)
		return _reset_gpio();
	else // It's redundant, but some people use for a style
		return _soft_reset();

> +
> +	gpiod_set_value_cansleep(st->gpio_reset, 0);
> +	usleep_range(10, 20);
> +	gpiod_set_value_cansleep(st->gpio_reset, 1);
> +
> +	/* data must not be written during reset timeframe */
> +	usleep_range(100, 200);
> +
> +	return 0;
> +}

...

> +		ret = regmap_bulk_read(st->regmap,
> +				       chan->address,

> +				       st->transf_buf, 2);

sizeof() ?

> +		if (ret)
> +			return 0;

...

> +		st->transf_buf[0] = ((u16)val >> 6);

Why explicit casting?

> +		st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;
> +		return regmap_bulk_write(st->regmap, chan->address,
> +					 st->transf_buf, 2);

sizeof() ?

...

> +static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,
> +				   struct iio_chan_spec const *chan,
> +				   const int **vals, int *type, int *length,
> +				   long mask)
> +{
> +	switch (mask) {
> +	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> +		*type = IIO_VAL_INT;
> +		*vals = ad5770r_filter_freqs;
> +		*length = ARRAY_SIZE(ad5770r_filter_freqs);
> +		return IIO_AVAIL_LIST;
> +	}
> +

> +	return -EINVAL;

default case?

> +}

...

> +	ret = kstrtobool(buf, &readin);
> +	if (ret)
> +		return ret;
> +

> +	readin = !readin;

I think using ! directly in places where it's needed will be helpful ti
understand the code.

> +
> +	regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);
> +	if (chan->channel == 0 &&
> +	    st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {
> +		regval |= AD5770R_CFG_CH0_SINK_EN(readin);
> +		mask = BIT(chan->channel) + BIT(7);
> +	} else {
> +		mask = BIT(chan->channel);
> +	}
> +	ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,
> +				 regval);
> +	if (ret)
> +		return ret;
> +
> +	regval = AD5770R_CH_SET(readin, chan->channel);
> +	ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,
> +				 BIT(chan->channel), regval);
> +	if (ret)
> +		return ret;
> +
> +	st->ch_pwr_down[chan->channel] = !readin;

...

> +	int ret, tmp[2], min, max;
> +	unsigned int num;
> +	struct fwnode_handle *child;
> +
> +	num = device_get_child_node_count(&st->spi->dev);
> +	if (num != AD5770R_MAX_CHANNELS)
> +		return -EINVAL;
> +
> +	device_for_each_child_node(&st->spi->dev, child) {
> +		ret = fwnode_property_read_u32(child, "num", &num);
> +		if (ret)
> +			return ret;
> +		if (num > AD5770R_MAX_CHANNELS)
> +			return -EINVAL;
> +
> +		ret = fwnode_property_read_u32_array(child,
> +						     "adi,range-microamp",

> +						     tmp, 2);

sizeof()?

And perhaps
	u32 tmp[2];

> +		if (ret)
> +			return ret;
> +
> +		min = tmp[0] / 1000;
> +		max = tmp[1] / 1000;
> +		ret = ad5770r_store_output_range(st, min, max, num);
> +		if (ret)
> +			return ret;
> +	}

> +	return ret;

ret might be uninitialized?

In any case, shouldn't be
	return 0;
?

> +}

...

> +	st->external_res = fwnode_property_read_bool(st->spi->dev.fwnode,
> +						     "adi,external-resistor");

Use of fwnode (and esp. w/o dev_fwnode() helper) looks inconsistent here.
Why not device_property_...()?

> +	return ret;

return 0;

...

> +static const struct of_device_id ad5770r_of_id[] = {
> +	{ .compatible = "adi,ad5770r", },

> +	{},

No need comma in terminator line.

> +};
> +MODULE_DEVICE_TABLE(of, ad5770r_of_id);
> +
> +static const struct spi_device_id ad5770r_id[] = {
> +	{ "ad5770r", 0 },

> +	{},

Ditto.

> +};

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 1/2] iio: dac: ad5770r: Add AD5770R support

[Ardelean, Alexandru]

On Sat, 2020-03-21 at 23:09 +0200, Andy Shevchenko wrote:
> [External]
> 
> On Tue, Feb 18, 2020 at 02:10:30PM +0200, Alexandru Tachici wrote:
> > The AD5770R is a 6-channel, 14-bit resolution, low noise, programmable
> > current output digital-to-analog converter (DAC) for photonics control
> > applications.
> > 
> > It contains five 14-bit resolution current sourcing DAC channels and one
> > 14-bit resolution current sourcing/sinking DAC channel.
> 

This patch made it into linux-next.
Doing a v2 now may be a bit noisy.

Maybe we can tidy-this-up later.
To be honest, it won't be the highest on our list.
[ I know how that sounds ]

We can probably leave it for other people to clean it up.
[ People that want to start contributing to the kernel ]


> ...
> 
> > +#define AD5770R_CFG_CH0_SINK_EN(x)		(((x) & 0x1) << 7)
> > +#define AD5770R_CFG_SHUTDOWN_B(x, ch)		(((x) & 0x1) << (ch))
> 
> BIT(0) ?
> 
> > +#define AD5770R_REF_RESISTOR_SEL(x)		(((x) & 0x1) << 2)
> 
> Ditto.
> 
> > +#define AD5770R_CH_SET(x, ch)		(((x) & 0x1) << (ch))
> 
> Ditto.
> 
> ...
> 
> > +enum ad5770r_ch0_modes {
> > +	AD5770R_CH0_0_300 = 0,
> > +	AD5770R_CH0_NEG_60_0,
> > +	AD5770R_CH0_NEG_60_300
> > +};
> > +
> > +enum ad5770r_ch1_modes {
> > +	AD5770R_CH1_0_140_LOW_HEAD = 1,
> > +	AD5770R_CH1_0_140_LOW_NOISE,
> > +	AD5770R_CH1_0_250
> > +};
> > +
> > +enum ad5770r_ch2_5_modes {
> > +	AD5770R_CH_LOW_RANGE = 0,
> > +	AD5770R_CH_HIGH_RANGE
> > +};
> > +
> > +enum ad5770r_ref_v {
> > +	AD5770R_EXT_2_5_V = 0,
> > +	AD5770R_INT_1_25_V_OUT_ON,
> > +	AD5770R_EXT_1_25_V,
> > +	AD5770R_INT_1_25_V_OUT_OFF
> > +};
> > +
> > +enum ad5770r_output_filter_resistor {
> > +	AD5770R_FILTER_60_OHM = 0x0,
> > +	AD5770R_FILTER_5_6_KOHM = 0x5,
> > +	AD5770R_FILTER_11_2_KOHM,
> > +	AD5770R_FILTER_22_2_KOHM,
> > +	AD5770R_FILTER_44_4_KOHM,
> > +	AD5770R_FILTER_104_KOHM,
> 
> It would be nice to go consistent about last entry in enums. Are they
> terminators? For me it doesn't look like it (new revision of hardware
> always can use extended lists of modes, etc).
> 
> So, I think leaving comma for all above is a right thing to do.
> 
> > +};
> 
> ...
> 
> > +static const unsigned int ad5770r_filter_reg_vals[] = {
> > +	AD5770R_FILTER_104_KOHM,
> > +	AD5770R_FILTER_44_4_KOHM,
> > +	AD5770R_FILTER_22_2_KOHM,
> > +	AD5770R_FILTER_11_2_KOHM,
> > +	AD5770R_FILTER_5_6_KOHM,
> > +	AD5770R_FILTER_60_OHM
> > +};
> 
> Ditto.
> 
> ...
> 
> > +	return regmap_write(st->regmap,
> > +			    AD5770R_OUTPUT_RANGE(channel), regval);
> 
> It fits one line (even has room for one character more)
> Perhaps you may consider to amend settings of your text editor?
> Please fix all similar places in all of your patches.
> 
> ...
> 
> > +static int ad5770r_reset(struct ad5770r_state *st)
> > +{
> > +	/* Perform software reset if no GPIO provided */
> > +	if (!st->gpio_reset)
> > +		return ad5770r_soft_reset(st);
> 
> Perhaps split this to _reset_gpio() and do
> 
> 	if (gpio)
> 		return _reset_gpio();
> 	else // It's redundant, but some people use for a style
> 		return _soft_reset();
> 
> > +
> > +	gpiod_set_value_cansleep(st->gpio_reset, 0);
> > +	usleep_range(10, 20);
> > +	gpiod_set_value_cansleep(st->gpio_reset, 1);
> > +
> > +	/* data must not be written during reset timeframe */
> > +	usleep_range(100, 200);
> > +
> > +	return 0;
> > +}
> 
> ...
> 
> > +		ret = regmap_bulk_read(st->regmap,
> > +				       chan->address,
> > +				       st->transf_buf, 2);
> 
> sizeof() ?
> 
> > +		if (ret)
> > +			return 0;
> 
> ...
> 
> > +		st->transf_buf[0] = ((u16)val >> 6);
> 
> Why explicit casting?
> 
> > +		st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;
> > +		return regmap_bulk_write(st->regmap, chan->address,
> > +					 st->transf_buf, 2);
> 
> sizeof() ?
> 
> ...
> 
> > +static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,
> > +				   struct iio_chan_spec const *chan,
> > +				   const int **vals, int *type, int *length,
> > +				   long mask)
> > +{
> > +	switch (mask) {
> > +	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> > +		*type = IIO_VAL_INT;
> > +		*vals = ad5770r_filter_freqs;
> > +		*length = ARRAY_SIZE(ad5770r_filter_freqs);
> > +		return IIO_AVAIL_LIST;
> > +	}
> > +
> > +	return -EINVAL;
> 
> default case?
> 
> > +}
> 
> ...
> 
> > +	ret = kstrtobool(buf, &readin);
> > +	if (ret)
> > +		return ret;
> > +
> > +	readin = !readin;
> 
> I think using ! directly in places where it's needed will be helpful ti
> understand the code.
> 
> > +
> > +	regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);
> > +	if (chan->channel == 0 &&
> > +	    st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {
> > +		regval |= AD5770R_CFG_CH0_SINK_EN(readin);
> > +		mask = BIT(chan->channel) + BIT(7);
> > +	} else {
> > +		mask = BIT(chan->channel);
> > +	}
> > +	ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,
> > +				 regval);
> > +	if (ret)
> > +		return ret;
> > +
> > +	regval = AD5770R_CH_SET(readin, chan->channel);
> > +	ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,
> > +				 BIT(chan->channel), regval);
> > +	if (ret)
> > +		return ret;
> > +
> > +	st->ch_pwr_down[chan->channel] = !readin;
> 
> ...
> 
> > +	int ret, tmp[2], min, max;
> > +	unsigned int num;
> > +	struct fwnode_handle *child;
> > +
> > +	num = device_get_child_node_count(&st->spi->dev);
> > +	if (num != AD5770R_MAX_CHANNELS)
> > +		return -EINVAL;
> > +
> > +	device_for_each_child_node(&st->spi->dev, child) {
> > +		ret = fwnode_property_read_u32(child, "num", &num);
> > +		if (ret)
> > +			return ret;
> > +		if (num > AD5770R_MAX_CHANNELS)
> > +			return -EINVAL;
> > +
> > +		ret = fwnode_property_read_u32_array(child,
> > +						     "adi,range-microamp",
> > +						     tmp, 2);
> 
> sizeof()?
> 
> And perhaps
> 	u32 tmp[2];
> 
> > +		if (ret)
> > +			return ret;
> > +
> > +		min = tmp[0] / 1000;
> > +		max = tmp[1] / 1000;
> > +		ret = ad5770r_store_output_range(st, min, max, num);
> > +		if (ret)
> > +			return ret;
> > +	}
> > +	return ret;
> 
> ret might be uninitialized?
> 
> In any case, shouldn't be
> 	return 0;
> ?
> 
> > +}
> 
> ...
> 
> > +	st->external_res = fwnode_property_read_bool(st->spi->dev.fwnode,
> > +						     "adi,external-resistor");
> 
> Use of fwnode (and esp. w/o dev_fwnode() helper) looks inconsistent here.
> Why not device_property_...()?
> 
> > +	return ret;
> 
> return 0;
> 
> ...
> 
> > +static const struct of_device_id ad5770r_of_id[] = {
> > +	{ .compatible = "adi,ad5770r", },
> > +	{},
> 
> No need comma in terminator line.
> 
> > +};
> > +MODULE_DEVICE_TABLE(of, ad5770r_of_id);
> > +
> > +static const struct spi_device_id ad5770r_id[] = {
> > +	{ "ad5770r", 0 },
> > +	{},
> 
> Ditto.
> 
> > +};

Re: [PATCH v4 1/2] iio: dac: ad5770r: Add AD5770R support

[andriy.shevchenko]

On Sun, Mar 22, 2020 at 09:17:06AM +0000, Ardelean, Alexandru wrote:
> On Sat, 2020-03-21 at 23:09 +0200, Andy Shevchenko wrote:
> > On Tue, Feb 18, 2020 at 02:10:30PM +0200, Alexandru Tachici wrote:
> > > The AD5770R is a 6-channel, 14-bit resolution, low noise, programmable
> > > current output digital-to-analog converter (DAC) for photonics control
> > > applications.
> > > 
> > > It contains five 14-bit resolution current sourcing DAC channels and one
> > > 14-bit resolution current sourcing/sinking DAC channel.
> > 
> 
> This patch made it into linux-next.
> Doing a v2 now may be a bit noisy.
> 
> Maybe we can tidy-this-up later.
> To be honest, it won't be the highest on our list.
> [ I know how that sounds ]

Yes, you may consider a follow up.

> We can probably leave it for other people to clean it up.
> [ People that want to start contributing to the kernel ]

Maybe, but isn't better to supply cleaner code in the first place?

I mean that these comments may be taken into consideration for the future
contributions.

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 2/2] dt-bindings: iio: dac: Add docs for AD5770R DAC

[Alexandru Tachici]

Adding dt-bindings documentation for AD5770R DAC.

Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
---
 .../bindings/iio/dac/adi,ad5770r.yaml         | 185 ++++++++++++++++++
 1 file changed, 185 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml

diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
new file mode 100644
index 000000000000..13d6b5ff479d
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
@@ -0,0 +1,185 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2020 Analog Devices Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bindings/iio/adc/adi,ad5770r.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD5770R DAC device driver
+
+maintainers:
+  - Mircea Caprioru <mircea.caprioru@analog.com>
+
+description: |
+  Bindings for the Analog Devices AD5770R current DAC device. Datasheet can be
+  found here:
+    https://www.analog.com/media/en/technical-documentation/data-sheets/AD5770R.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ad5770r
+
+  reg:
+    maxItems: 1
+
+  avdd-supply:
+    description:
+      AVdd voltage supply. Represents two different supplies in the datasheet
+      that are in fact the same.
+
+  iovdd-supply:
+    description:
+      Voltage supply for the chip interface.
+
+  vref-supply:
+    description: Specify the voltage of the external reference used.
+      Available reference options are 1.25 V or 2.5 V. If no
+      external reference declared then the device will use the
+      internal reference of 1.25 V.
+
+  adi,external-resistor:
+    description: Specify if an external 2.5k ohm resistor is used. If not
+      specified the device will use an internal 2.5k ohm resistor.
+      The precision resistor is used for reference current generation.
+    type: boolean
+
+  reset-gpios:
+    description: GPIO spec for the RESET pin. If specified, it will be
+      asserted during driver probe.
+    maxItems: 1
+
+  channel0:
+    description: Represents an external channel which are
+      connected to the DAC. Channel 0 can act both as a current
+      source and sink.
+    type: object
+
+    properties:
+      num:
+        description: This represents the channel number.
+        items:
+          const: 0
+
+      adi,range-microamp:
+          description: Output range of the channel.
+          oneOf:
+            - $ref: /schemas/types.yaml#/definitions/int32-array
+            - items:
+                - enum: [0 300000]
+                - enum: [-60000 0]
+                - enum: [-60000 300000]
+
+  channel1:
+    description: Represents an external channel which are
+      connected to the DAC.
+    type: object
+
+    properties:
+      num:
+        description: This represents the channel number.
+        items:
+          const: 1
+
+      adi,range-microamp:
+          description: Output range of the channel.
+          oneOf:
+            - $ref: /schemas/types.yaml#/definitions/uint32-array
+            - items:
+                - enum: [0 140000]
+                - enum: [0 250000]
+
+  channel2:
+    description: Represents an external channel which are
+      connected to the DAC.
+    type: object
+
+    properties:
+      num:
+        description: This represents the channel number.
+        items:
+          const: 2
+
+      adi,range-microamp:
+          description: Output range of the channel.
+          oneOf:
+            - $ref: /schemas/types.yaml#/definitions/uint32-array
+            - items:
+                - enum: [0 140000]
+                - enum: [0 250000]
+
+patternProperties:
+  "^channel@([3-5])$":
+    type: object
+    description: Represents the external channels which are connected to the DAC.
+    properties:
+      num:
+        description: This represents the channel number.
+        items:
+          minimum: 3
+          maximum: 5
+
+      adi,range-microamp:
+          description: Output range of the channel.
+          oneOf:
+            - $ref: /schemas/types.yaml#/definitions/uint32-array
+            - items:
+                - enum: [0 45000]
+                - enum: [0 100000]
+
+required:
+- reg
+- diff-channels
+- channel0
+- channel1
+- channel2
+- channel3
+- channel4
+- channel5
+
+examples:
+  - |
+        spi {
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                ad5770r@0 {
+                        compatible = "ad5770r";
+                        reg = <0>;
+                        spi-max-frequency = <1000000>;
+                        vref-supply = <&vref>;
+                        adi,external-resistor;
+                        reset-gpios = <&gpio 22 0>;
+
+                        channel@0 {
+                                num = <0>;
+                                adi,range-microamp = <(-60000) 300000>;
+                        };
+
+                        channel@1 {
+                                num = <1>;
+                                adi,range-microamp = <0 140000>;
+                        };
+
+                        channel@2 {
+                                num = <2>;
+                                adi,range-microamp = <0 55000>;
+                        };
+
+                        channel@3 {
+                                num = <3>;
+                                adi,range-microamp = <0 45000>;
+                        };
+
+                        channel@4 {
+                                num = <4>;
+                                adi,range-microamp = <0 45000>;
+                        };
+
+                        channel@5 {
+                                num = <5>;
+                                adi,range-microamp = <0 45000>;
+                        };
+                };
+        };
+...
-- 
2.20.1

Re: [PATCH v4 2/2] dt-bindings: iio: dac: Add docs for AD5770R DAC

[Jonathan Cameron]

On Tue, 18 Feb 2020 14:10:31 +0200
Alexandru Tachici <alexandru.tachici@analog.com> wrote:

> Adding dt-bindings documentation for AD5770R DAC.
> 
> Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
> Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
> ---
>  .../bindings/iio/dac/adi,ad5770r.yaml         | 185 ++++++++++++++++++
>  1 file changed, 185 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
> new file mode 100644
> index 000000000000..13d6b5ff479d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
> @@ -0,0 +1,185 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2020 Analog Devices Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/bindings/iio/adc/adi,ad5770r.yaml#
Umm. adc?  Please make sure you run the build tests on bindings and that
you have a recent version of the dt schema stuff.

I have applied with that fixed, but will be looking to add an Ack from Rob
ideally before I push this out as a non rebasing tree.

Thanks,

Jonathan

> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices AD5770R DAC device driver
> +
> +maintainers:
> +  - Mircea Caprioru <mircea.caprioru@analog.com>
> +
> +description: |
> +  Bindings for the Analog Devices AD5770R current DAC device. Datasheet can be
> +  found here:
> +    https://www.analog.com/media/en/technical-documentation/data-sheets/AD5770R.pdf
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ad5770r
> +
> +  reg:
> +    maxItems: 1
> +
> +  avdd-supply:
> +    description:
> +      AVdd voltage supply. Represents two different supplies in the datasheet
> +      that are in fact the same.
> +
> +  iovdd-supply:
> +    description:
> +      Voltage supply for the chip interface.
> +
> +  vref-supply:
> +    description: Specify the voltage of the external reference used.
> +      Available reference options are 1.25 V or 2.5 V. If no
> +      external reference declared then the device will use the
> +      internal reference of 1.25 V.
> +
> +  adi,external-resistor:
> +    description: Specify if an external 2.5k ohm resistor is used. If not
> +      specified the device will use an internal 2.5k ohm resistor.
> +      The precision resistor is used for reference current generation.
> +    type: boolean
> +
> +  reset-gpios:
> +    description: GPIO spec for the RESET pin. If specified, it will be
> +      asserted during driver probe.
> +    maxItems: 1
> +
> +  channel0:
> +    description: Represents an external channel which are
> +      connected to the DAC. Channel 0 can act both as a current
> +      source and sink.
> +    type: object
> +
> +    properties:
> +      num:
> +        description: This represents the channel number.
> +        items:
> +          const: 0
> +
> +      adi,range-microamp:
> +          description: Output range of the channel.
> +          oneOf:
> +            - $ref: /schemas/types.yaml#/definitions/int32-array
> +            - items:
> +                - enum: [0 300000]
> +                - enum: [-60000 0]
> +                - enum: [-60000 300000]
> +
> +  channel1:
> +    description: Represents an external channel which are
> +      connected to the DAC.
> +    type: object
> +
> +    properties:
> +      num:
> +        description: This represents the channel number.
> +        items:
> +          const: 1
> +
> +      adi,range-microamp:
> +          description: Output range of the channel.
> +          oneOf:
> +            - $ref: /schemas/types.yaml#/definitions/uint32-array
> +            - items:
> +                - enum: [0 140000]
> +                - enum: [0 250000]
> +
> +  channel2:
> +    description: Represents an external channel which are
> +      connected to the DAC.
> +    type: object
> +
> +    properties:
> +      num:
> +        description: This represents the channel number.
> +        items:
> +          const: 2
> +
> +      adi,range-microamp:
> +          description: Output range of the channel.
> +          oneOf:
> +            - $ref: /schemas/types.yaml#/definitions/uint32-array
> +            - items:
> +                - enum: [0 140000]
> +                - enum: [0 250000]
> +
> +patternProperties:
> +  "^channel@([3-5])$":
> +    type: object
> +    description: Represents the external channels which are connected to the DAC.
> +    properties:
> +      num:
> +        description: This represents the channel number.
> +        items:
> +          minimum: 3
> +          maximum: 5
> +
> +      adi,range-microamp:
> +          description: Output range of the channel.
> +          oneOf:
> +            - $ref: /schemas/types.yaml#/definitions/uint32-array
> +            - items:
> +                - enum: [0 45000]
> +                - enum: [0 100000]
> +
> +required:
> +- reg
> +- diff-channels
> +- channel0
> +- channel1
> +- channel2
> +- channel3
> +- channel4
> +- channel5
> +
> +examples:
> +  - |
> +        spi {
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                ad5770r@0 {
> +                        compatible = "ad5770r";
> +                        reg = <0>;
> +                        spi-max-frequency = <1000000>;
> +                        vref-supply = <&vref>;
> +                        adi,external-resistor;
> +                        reset-gpios = <&gpio 22 0>;
> +
> +                        channel@0 {
> +                                num = <0>;
> +                                adi,range-microamp = <(-60000) 300000>;
> +                        };
> +
> +                        channel@1 {
> +                                num = <1>;
> +                                adi,range-microamp = <0 140000>;
> +                        };
> +
> +                        channel@2 {
> +                                num = <2>;
> +                                adi,range-microamp = <0 55000>;
> +                        };
> +
> +                        channel@3 {
> +                                num = <3>;
> +                                adi,range-microamp = <0 45000>;
> +                        };
> +
> +                        channel@4 {
> +                                num = <4>;
> +                                adi,range-microamp = <0 45000>;
> +                        };
> +
> +                        channel@5 {
> +                                num = <5>;
> +                                adi,range-microamp = <0 45000>;
> +                        };
> +                };
> +        };
> +...

Re: [PATCH v4 2/2] dt-bindings: iio: dac: Add docs for AD5770R DAC

[Rob Herring]

On Tue, Feb 18, 2020 at 02:10:31PM +0200, Alexandru Tachici wrote:
> Adding dt-bindings documentation for AD5770R DAC.

DT list needs to be Cc'ed if you want bindings reviewed.

> Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
> Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
> ---
>  .../bindings/iio/dac/adi,ad5770r.yaml         | 185 ++++++++++++++++++
>  1 file changed, 185 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
> new file mode 100644
> index 000000000000..13d6b5ff479d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
> @@ -0,0 +1,185 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2020 Analog Devices Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/bindings/iio/adc/adi,ad5770r.yaml#

Jonathan mentioned 'adc' part, but 'bindings' is also wrong. Should be:

.../schemas/iio/dac/...

> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices AD5770R DAC device driver
> +
> +maintainers:
> +  - Mircea Caprioru <mircea.caprioru@analog.com>
> +
> +description: |
> +  Bindings for the Analog Devices AD5770R current DAC device. Datasheet can be
> +  found here:
> +    https://www.analog.com/media/en/technical-documentation/data-sheets/AD5770R.pdf
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ad5770r
> +
> +  reg:
> +    maxItems: 1
> +
> +  avdd-supply:
> +    description:
> +      AVdd voltage supply. Represents two different supplies in the datasheet
> +      that are in fact the same.
> +
> +  iovdd-supply:
> +    description:
> +      Voltage supply for the chip interface.
> +
> +  vref-supply:
> +    description: Specify the voltage of the external reference used.
> +      Available reference options are 1.25 V or 2.5 V. If no
> +      external reference declared then the device will use the
> +      internal reference of 1.25 V.
> +
> +  adi,external-resistor:
> +    description: Specify if an external 2.5k ohm resistor is used. If not
> +      specified the device will use an internal 2.5k ohm resistor.
> +      The precision resistor is used for reference current generation.
> +    type: boolean
> +
> +  reset-gpios:
> +    description: GPIO spec for the RESET pin. If specified, it will be
> +      asserted during driver probe.
> +    maxItems: 1
> +
> +  channel0:

channel@0 ???

Once you fix that, your example will start failing.

> +    description: Represents an external channel which are
> +      connected to the DAC. Channel 0 can act both as a current
> +      source and sink.
> +    type: object
> +
> +    properties:
> +      num:

Use 'reg' instead.

> +        description: This represents the channel number.
> +        items:

You can drop items.

> +          const: 0
> +
> +      adi,range-microamp:
> +          description: Output range of the channel.
> +          oneOf:
> +            - $ref: /schemas/types.yaml#/definitions/int32-array

*-microamp already has a type, so this should be dropped. However, I 
believe it's unsigned currently, but we can fix it to be signed.

> +            - items:
> +                - enum: [0 300000]
> +                - enum: [-60000 0]
> +                - enum: [-60000 300000]

Negative values don't yet work until we fix dtc to be able to output 
negative values. For now, can you just avoid negative numbers in the 
example.

What's defined here doesn't match the example. You are saying there are 
3 cells with 2 possible values each. I think you want:

oneOf:
  - items:
      - const: 0
      - const: 300000
  - items:
      - const: -60000
      - const: 0
  - items:
      - const: -60000
      - const: 300000
      

> +
> +  channel1:
> +    description: Represents an external channel which are
> +      connected to the DAC.
> +    type: object
> +
> +    properties:
> +      num:
> +        description: This represents the channel number.
> +        items:
> +          const: 1
> +
> +      adi,range-microamp:
> +          description: Output range of the channel.
> +          oneOf:
> +            - $ref: /schemas/types.yaml#/definitions/uint32-array
> +            - items:
> +                - enum: [0 140000]
> +                - enum: [0 250000]
> +
> +  channel2:
> +    description: Represents an external channel which are
> +      connected to the DAC.
> +    type: object
> +
> +    properties:
> +      num:
> +        description: This represents the channel number.
> +        items:
> +          const: 2
> +
> +      adi,range-microamp:
> +          description: Output range of the channel.
> +          oneOf:
> +            - $ref: /schemas/types.yaml#/definitions/uint32-array
> +            - items:
> +                - enum: [0 140000]
> +                - enum: [0 250000]
> +
> +patternProperties:
> +  "^channel@([3-5])$":
> +    type: object
> +    description: Represents the external channels which are connected to the DAC.
> +    properties:
> +      num:
> +        description: This represents the channel number.
> +        items:
> +          minimum: 3
> +          maximum: 5
> +
> +      adi,range-microamp:
> +          description: Output range of the channel.
> +          oneOf:
> +            - $ref: /schemas/types.yaml#/definitions/uint32-array
> +            - items:
> +                - enum: [0 45000]
> +                - enum: [0 100000]
> +
> +required:
> +- reg
> +- diff-channels
> +- channel0
> +- channel1
> +- channel2
> +- channel3
> +- channel4
> +- channel5
> +
> +examples:
> +  - |
> +        spi {
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                ad5770r@0 {
> +                        compatible = "ad5770r";
> +                        reg = <0>;
> +                        spi-max-frequency = <1000000>;
> +                        vref-supply = <&vref>;
> +                        adi,external-resistor;
> +                        reset-gpios = <&gpio 22 0>;
> +
> +                        channel@0 {
> +                                num = <0>;
> +                                adi,range-microamp = <(-60000) 300000>;
> +                        };
> +
> +                        channel@1 {
> +                                num = <1>;
> +                                adi,range-microamp = <0 140000>;
> +                        };
> +
> +                        channel@2 {
> +                                num = <2>;
> +                                adi,range-microamp = <0 55000>;
> +                        };
> +
> +                        channel@3 {
> +                                num = <3>;
> +                                adi,range-microamp = <0 45000>;
> +                        };
> +
> +                        channel@4 {
> +                                num = <4>;
> +                                adi,range-microamp = <0 45000>;
> +                        };
> +
> +                        channel@5 {
> +                                num = <5>;
> +                                adi,range-microamp = <0 45000>;
> +                        };
> +                };
> +        };
> +...
> -- 
> 2.20.1
> 

Re: [PATCH v4 2/2] dt-bindings: iio: dac: Add docs for AD5770R DAC

[Jonathan Cameron]

On Thu, 19 Mar 2020 18:49:22 -0600
Rob Herring <robh@kernel.org> wrote:

> On Tue, Feb 18, 2020 at 02:10:31PM +0200, Alexandru Tachici wrote:
> > Adding dt-bindings documentation for AD5770R DAC.  
> 
> DT list needs to be Cc'ed if you want bindings reviewed.

Doh. I missed that.

> 
> > Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
> > Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
> > ---
> >  .../bindings/iio/dac/adi,ad5770r.yaml         | 185 ++++++++++++++++++
> >  1 file changed, 185 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
> > new file mode 100644
> > index 000000000000..13d6b5ff479d
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5770r.yaml
> > @@ -0,0 +1,185 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +# Copyright 2020 Analog Devices Inc.
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/bindings/iio/adc/adi,ad5770r.yaml#  
> 
> Jonathan mentioned 'adc' part, but 'bindings' is also wrong. Should be:

Alexandru, please send a fixup patch for the various things Rob has highlighted.

Jonathan


> 
> .../schemas/iio/dac/...
> 
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Analog Devices AD5770R DAC device driver
> > +
> > +maintainers:
> > +  - Mircea Caprioru <mircea.caprioru@analog.com>
> > +
> > +description: |
> > +  Bindings for the Analog Devices AD5770R current DAC device. Datasheet can be
> > +  found here:
> > +    https://www.analog.com/media/en/technical-documentation/data-sheets/AD5770R.pdf
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - adi,ad5770r
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  avdd-supply:
> > +    description:
> > +      AVdd voltage supply. Represents two different supplies in the datasheet
> > +      that are in fact the same.
> > +
> > +  iovdd-supply:
> > +    description:
> > +      Voltage supply for the chip interface.
> > +
> > +  vref-supply:
> > +    description: Specify the voltage of the external reference used.
> > +      Available reference options are 1.25 V or 2.5 V. If no
> > +      external reference declared then the device will use the
> > +      internal reference of 1.25 V.
> > +
> > +  adi,external-resistor:
> > +    description: Specify if an external 2.5k ohm resistor is used. If not
> > +      specified the device will use an internal 2.5k ohm resistor.
> > +      The precision resistor is used for reference current generation.
> > +    type: boolean
> > +
> > +  reset-gpios:
> > +    description: GPIO spec for the RESET pin. If specified, it will be
> > +      asserted during driver probe.
> > +    maxItems: 1
> > +
> > +  channel0:  
> 
> channel@0 ???
> 
> Once you fix that, your example will start failing.
> 
> > +    description: Represents an external channel which are
> > +      connected to the DAC. Channel 0 can act both as a current
> > +      source and sink.
> > +    type: object
> > +
> > +    properties:
> > +      num:  
> 
> Use 'reg' instead.
> 
> > +        description: This represents the channel number.
> > +        items:  
> 
> You can drop items.
> 
> > +          const: 0
> > +
> > +      adi,range-microamp:
> > +          description: Output range of the channel.
> > +          oneOf:
> > +            - $ref: /schemas/types.yaml#/definitions/int32-array  
> 
> *-microamp already has a type, so this should be dropped. However, I 
> believe it's unsigned currently, but we can fix it to be signed.
> 
> > +            - items:
> > +                - enum: [0 300000]
> > +                - enum: [-60000 0]
> > +                - enum: [-60000 300000]  
> 
> Negative values don't yet work until we fix dtc to be able to output 
> negative values. For now, can you just avoid negative numbers in the 
> example.
> 
> What's defined here doesn't match the example. You are saying there are 
> 3 cells with 2 possible values each. I think you want:
> 
> oneOf:
>   - items:
>       - const: 0
>       - const: 300000
>   - items:
>       - const: -60000
>       - const: 0
>   - items:
>       - const: -60000
>       - const: 300000
>       
> 
> > +
> > +  channel1:
> > +    description: Represents an external channel which are
> > +      connected to the DAC.
> > +    type: object
> > +
> > +    properties:
> > +      num:
> > +        description: This represents the channel number.
> > +        items:
> > +          const: 1
> > +
> > +      adi,range-microamp:
> > +          description: Output range of the channel.
> > +          oneOf:
> > +            - $ref: /schemas/types.yaml#/definitions/uint32-array
> > +            - items:
> > +                - enum: [0 140000]
> > +                - enum: [0 250000]
> > +
> > +  channel2:
> > +    description: Represents an external channel which are
> > +      connected to the DAC.
> > +    type: object
> > +
> > +    properties:
> > +      num:
> > +        description: This represents the channel number.
> > +        items:
> > +          const: 2
> > +
> > +      adi,range-microamp:
> > +          description: Output range of the channel.
> > +          oneOf:
> > +            - $ref: /schemas/types.yaml#/definitions/uint32-array
> > +            - items:
> > +                - enum: [0 140000]
> > +                - enum: [0 250000]
> > +
> > +patternProperties:
> > +  "^channel@([3-5])$":
> > +    type: object
> > +    description: Represents the external channels which are connected to the DAC.
> > +    properties:
> > +      num:
> > +        description: This represents the channel number.
> > +        items:
> > +          minimum: 3
> > +          maximum: 5
> > +
> > +      adi,range-microamp:
> > +          description: Output range of the channel.
> > +          oneOf:
> > +            - $ref: /schemas/types.yaml#/definitions/uint32-array
> > +            - items:
> > +                - enum: [0 45000]
> > +                - enum: [0 100000]
> > +
> > +required:
> > +- reg
> > +- diff-channels
> > +- channel0
> > +- channel1
> > +- channel2
> > +- channel3
> > +- channel4
> > +- channel5
> > +
> > +examples:
> > +  - |
> > +        spi {
> > +                #address-cells = <1>;
> > +                #size-cells = <0>;
> > +
> > +                ad5770r@0 {
> > +                        compatible = "ad5770r";
> > +                        reg = <0>;
> > +                        spi-max-frequency = <1000000>;
> > +                        vref-supply = <&vref>;
> > +                        adi,external-resistor;
> > +                        reset-gpios = <&gpio 22 0>;
> > +
> > +                        channel@0 {
> > +                                num = <0>;
> > +                                adi,range-microamp = <(-60000) 300000>;
> > +                        };
> > +
> > +                        channel@1 {
> > +                                num = <1>;
> > +                                adi,range-microamp = <0 140000>;
> > +                        };
> > +
> > +                        channel@2 {
> > +                                num = <2>;
> > +                                adi,range-microamp = <0 55000>;
> > +                        };
> > +
> > +                        channel@3 {
> > +                                num = <3>;
> > +                                adi,range-microamp = <0 45000>;
> > +                        };
> > +
> > +                        channel@4 {
> > +                                num = <4>;
> > +                                adi,range-microamp = <0 45000>;
> > +                        };
> > +
> > +                        channel@5 {
> > +                                num = <5>;
> > +                                adi,range-microamp = <0 45000>;
> > +                        };
> > +                };
> > +        };
> > +...
> > -- 
> > 2.20.1
> >