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Subject[PATCH] iio: dac: DS4424: add Maxim DS4422/DS4424 DAC driver support
Date
From: "Ismail H. Kose" <ihkose@gmail.com>

Add iio driver for DS4422/DS4424 chips that support two/four channel 7-bit
Sink/Source Current DAC.

The driver supports device tree and platfrom files for the configurations.

Datasheet publicly available at:
https://datasheets.maximintegrated.com/en/ds/DS4422-DS4424.pdf

Signed-off-by: Ismail Kose <Ismail.Kose@maximintegrated.com>
---
.../devicetree/bindings/iio/dac/ds4424.txt | 41 ++
drivers/iio/dac/Kconfig | 9 +
drivers/iio/dac/Makefile | 1 +
drivers/iio/dac/ds4424.c | 733 +++++++++++++++++++++
include/linux/iio/dac/ds4424.h | 29 +
5 files changed, 813 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/dac/ds4424.txt
create mode 100644 drivers/iio/dac/ds4424.c
create mode 100644 include/linux/iio/dac/ds4424.h

diff --git a/Documentation/devicetree/bindings/iio/dac/ds4424.txt b/Documentation/devicetree/bindings/iio/dac/ds4424.txt
new file mode 100644
index 000000000000..03c1b575a6db
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/ds4424.txt
@@ -0,0 +1,41 @@
+Maxim Integrated DS4422/DS4424 DAC device driver
+
+Required properties:
+ - compatible: Must be "maxim,ds4422" or "maxim,ds4424"
+ - reg: Should contain the DAC I2C address
+ - min_rfs, max_rfs: In order to get the correct processed data values,
+ these resistor values should be changed to the correct values
+ that match the user's system resistor values for RFS0 to RFS1.
+ Resistance values for rfs_resistor are listed in 100 Ohm units;
+ ie, 800 is 80K. Acceptable RFS values are 40K to 160K.
+ - ifs_scale: 61000*100 = 6100000 = 100,000,000 * .976/16
+ - max_picoamp: Should contain DAC maximum pico amper value.
+ - rfs_resistor: Should contain reference resistor
+ - iio map: Should contain IIO Map info
+
+Optional properties:
+ - vcc-supply: Power supply us optional. If not defined, driver will ignore it.
+
+Example:
+ ds4224@10 {
+ compatible = "maxim,ds4424";
+ reg = <0x10>; /* When A0, A1 pins are ground */
+ vcc-supply = "dac_vcc_3v3";
+ max-picoamp = <200000000>; /* 200uA */
+ ifs-scale = <61000>;
+ /* In order to get the correct processed data values,
+ these resistor values should be changed to the correct values that match the
+ user's system resistor values for RFS0 to RFS1.
+ Resistance values for rfs_resistor are listed in 100 Ohm units;
+ ie, 800 is 80K. Acceptable RFS values are 40K to 160K.
+ */
+ min-rfs = <400>;
+ max-rfs = <1600>;
+ rfs-resistors = <400 800 1000 1600>;
+ dac-iio-map =
+ /* consumer_dev_name, consumer_channel, adc_channel_label */
+ "ds4424_dac-consumer-dev_name-1", "ds4424_dac1", "OUT1",
+ "ds4424_dac-consumer-dev_name-2", "ds4424_dac2", "OUT2",
+ "ds4424_dac-consumer-dev_name-3", "ds4424_dac3", "OUT3",
+ "ds4424_dac-consumer-dev_name-4", "ds4424_dac4", "OUT4";
+ };
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index df5abc46cd3f..6f569c0ac88a 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -309,4 +309,13 @@ config VF610_DAC
This driver can also be built as a module. If so, the module will
be called vf610_dac.

+config DAC_DS4424
+ tristate "Maxim Integrated DS4422/DS4424 DAC driver"
+ depends on I2C
+ help
+ If you say yes here you get support for Maxim chip DS4422, DS4424.
+
+ This driver can also be built as a module. If so, the module
+ will be called DAC_DS4424.
+
endmenu
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 603587cc2f07..fa77510a5538 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -33,3 +33,4 @@ obj-$(CONFIG_MCP4922) += mcp4922.o
obj-$(CONFIG_STM32_DAC_CORE) += stm32-dac-core.o
obj-$(CONFIG_STM32_DAC) += stm32-dac.o
obj-$(CONFIG_VF610_DAC) += vf610_dac.o
+obj-$(CONFIG_DAC_DS4424) += ds4424.o
diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c
new file mode 100644
index 000000000000..d13590a00c79
--- /dev/null
+++ b/drivers/iio/dac/ds4424.c
@@ -0,0 +1,733 @@
+/*
+ * Maxim Integrated
+ * 7-bit, Multi-Channel Sink/Source Current DAC Driver
+ * Copyright (C) 2017 Maxim Integrated
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+#include <linux/iio/machine.h>
+#include <linux/iio/dac/ds4424.h>
+
+#define DS4424_DAC_ADDR(chan) ((chan) + 0xf8)
+#define SOURCE_I 1
+#define SINK_I 0
+
+#define PWR_ON true
+#define PWR_OFF false
+
+#define DS4424_CHANNEL(chan) { \
+ .type = IIO_CURRENT, \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = chan, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_PROCESSED) | \
+ BIT(IIO_CHAN_INFO_SCALE),\
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET), \
+ .address = DS4424_DAC_ADDR(chan), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 8, \
+ .storagebits = 8, \
+ .shift = 0, \
+ }, \
+}
+
+union raw_data {
+ struct {
+ u8 dx:7;
+ u8 source_bit:1; /* 1 is source, 0 is sink */
+ };
+ u8 bits;
+};
+
+enum ds4424_device_ids {
+ ID_DS4422,
+ ID_DS4424,
+};
+
+struct ds4424_data {
+ struct i2c_client *client;
+ struct mutex lock;
+ uint16_t raw[DS442X_MAX_DAC_CHANNELS];
+#ifdef CONFIG_PM_SLEEP
+ uint16_t save[DS442X_MAX_DAC_CHANNELS];
+#endif
+ uint32_t max_rfs;
+ uint32_t min_rfs;
+ uint32_t ifs_scale;
+ uint32_t max_picoamp;
+ uint32_t rfs_res[DS442X_MAX_DAC_CHANNELS];
+ struct iio_map dac_iio_map[DS442X_MAX_DAC_CHANNELS + 1];
+ struct regulator *vcc_reg;
+ const char *vcc_reg_name;
+ bool regulator_state;
+};
+
+static const struct ds4424_pdata ds4424_pdata_default = {
+ /* .vcc_supply_name = "dac_vdd_3v3", */
+ .min_rfs = 400,
+ .max_rfs = 1600,
+ .ifs_scale = 61000, /* 61000*100 = 6100000 = 100,000,000 * .976/16 */
+ .max_picoamp = 200000000,
+ .rfs_res = {400, 800, 1000, 1600},
+ .dac_iio_map = {
+ { .consumer_dev_name = "ds4424_dac-consumer-dev_name-1",
+ .consumer_channel = "ds4424_dac1",
+ .adc_channel_label = "OUT1"
+ },
+ {
+ .consumer_dev_name = "ds4424_dac-consumer-dev_name-2",
+ .consumer_channel = "ds4424_dac2",
+ .adc_channel_label = "OUT2"
+ },
+ {
+ .consumer_dev_name = "ds4424_dac-consumer-dev_name-3",
+ .consumer_channel = "ds4424_dac3",
+ .adc_channel_label = "OUT3"
+ },
+ {
+ .consumer_dev_name = "ds4424_dac-consumer-dev_name-4",
+ .consumer_channel = "ds4424_dac4",
+ .adc_channel_label = "OUT4"
+ },
+ {},
+ },
+};
+
+static const struct iio_chan_spec ds4424_channels[] = {
+ DS4424_CHANNEL(0),
+ DS4424_CHANNEL(1),
+ DS4424_CHANNEL(2),
+ DS4424_CHANNEL(3)
+};
+
+int ds4424_regulator_onoff(struct iio_dev *indio_dev, bool enable)
+{
+ struct ds4424_data *data = iio_priv(indio_dev);
+ int ret = 0;
+
+ if (data->vcc_reg == NULL)
+ return ret;
+
+ if (data->regulator_state == PWR_OFF && enable == PWR_ON) {
+ ret = regulator_enable(data->vcc_reg);
+ if (ret) {
+ pr_err("%s - enable vcc_reg failed, ret=%d\n",
+ __func__, ret);
+ goto done;
+ }
+ } else if (data->regulator_state == PWR_ON && enable == PWR_OFF) {
+ ret = regulator_disable(data->vcc_reg);
+ if (ret) {
+ pr_err("%s - disable vcc_reg failed, ret=%d\n",
+ __func__, ret);
+ goto done;
+ }
+ }
+
+ data->regulator_state = enable;
+done:
+ return ret;
+}
+
+static int ds4424_get_value(struct iio_dev *indio_dev,
+ int *val, int channel)
+{
+ struct ds4424_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ u8 outbuf[1];
+ u8 inbuf[1];
+ int ret;
+
+ if ((channel < 0) && (channel >= indio_dev->num_channels))
+ return -EINVAL;
+
+ outbuf[0] = DS4424_DAC_ADDR(channel);
+ mutex_lock(&data->lock);
+ ret = i2c_master_send(client, outbuf, 1);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ return ret;
+ } else if (ret != 1) {
+ mutex_unlock(&data->lock);
+ return -EIO;
+ }
+
+ ret = i2c_master_recv(client, inbuf, 1);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ return ret;
+ } else if (ret != 1) {
+ mutex_unlock(&data->lock);
+ return -EIO;
+ }
+
+ mutex_unlock(&data->lock);
+
+ *val = inbuf[0];
+ return 0;
+}
+
+/*
+ * DS4432 DAC control register 8 bits
+ * [7] 0: to sink; 1: to source
+ * [6:0] steps to sink/source
+ * bit[7] looks like a sign bit, but the value of the register is
+ * not a complemental code considering the bit[6:0] is a absolute
+ * distance from the zero point.
+ */
+
+/*
+ * val is positive if sourcing
+ * val is negative if sinking
+ * val can be -127 to 127
+ */
+static int ds4424_set_value(struct iio_dev *indio_dev,
+ int val, struct iio_chan_spec const *chan)
+{
+ struct ds4424_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ u8 outbuf[2];
+ int ret;
+ int max_val = ((1 << chan->scan_type.realbits) - 1);
+
+ if (val < 0 || val > max_val)
+ return -EINVAL;
+
+ if ((chan->channel < 0)
+ && (chan->channel >= indio_dev->num_channels))
+ return -EINVAL;
+
+ outbuf[0] = DS4424_DAC_ADDR(chan->channel);
+ outbuf[1] = (val & 0xff);
+
+ mutex_lock(&data->lock);
+ ret = i2c_master_send(client, outbuf, ARRAY_SIZE(outbuf));
+ mutex_unlock(&data->lock);
+
+ if (ret < 0)
+ return ret;
+ else if (ret >= 0 && ret != ARRAY_SIZE(outbuf))
+ return -EIO;
+
+ data->raw[chan->channel] = outbuf[1];
+ return 0;
+}
+
+static int ds4424_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ union raw_data raw;
+ int round_up, ret;
+ struct ds4424_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ /* Raw is processed a little bit
+ * outputs positive values for sourcing
+ * and negative values for sinking
+ */
+ ret = ds4424_get_value(indio_dev, val, chan->channel);
+ if (ret < 0) {
+ pr_err("%s : ds4424_get_value returned %d\n",
+ __func__, ret);
+ return ret;
+ }
+ raw.bits = *val;
+ *val = raw.dx;
+ if (raw.source_bit == SINK_I)
+ *val = -*val;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_PROCESSED:
+ /**
+ * To get the processed current using the 8-bit raw data:
+ * bit 7 is a 1 if sourcing current and it's a 0 if sinking
+ * current.
+ * The current full scale (Ifs) depends on the Rfs resistor
+ * value in ohms:
+ * Ifs = (0.976/Rfs)*(127/16)
+ * Then the current sourced or sinked can be determined as
+ * follows:
+ * I = Ifs * (Dx/127)
+ * where Dx is the value of the seven bits 6 to 0.
+ */
+ if (data->rfs_res[chan->channel] < data->min_rfs ||
+ data->rfs_res[chan->channel] > data->max_rfs) {
+ pr_err("%s : rfs_res out of range. rfs_res[%d]: %d\n",
+ __func__,
+ chan->channel,
+ data->rfs_res[chan->channel]);
+ return -EINVAL;
+ }
+
+ ret = ds4424_get_value(indio_dev, val, chan->channel);
+ if (ret < 0) {
+ pr_err("%s : ds4424_get_value returned %d\n",
+ __func__, ret);
+ return ret;
+ }
+ raw.bits = *val;
+ *val = data->ifs_scale * raw.dx * 100;
+ round_up = data->rfs_res[chan->channel] / 2;
+ *val = (*val + round_up) / data->rfs_res[chan->channel];
+
+ if (raw.source_bit == SINK_I)
+ *val = -*val;
+ *val = *val * 100; /* picoAmps */
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ round_up = data->rfs_res[chan->channel] / 2;
+ /* picoAmps */
+ *val = (data->ifs_scale * 10000 + round_up) /
+ data->rfs_res[chan->channel];
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_OFFSET:
+ *val = 0;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+/**
+ * val is positive if sourcing
+ * val is negative if sinking
+ */
+static int ds4424_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ union raw_data raw;
+ struct ds4424_data *data = iio_priv(indio_dev);
+ int val0, max_val, min_val, tmp_scale;
+
+ if (val2 != 0)
+ return -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+
+ max_val = ((1 << chan->scan_type.realbits)/2) - 1;
+ min_val = -max_val;
+ if ((val > max_val) || (val < min_val))
+ return -EINVAL;
+
+ if (val > 0) {
+ raw.source_bit = SOURCE_I;
+ raw.dx = val;
+ } else {
+ raw.source_bit = SINK_I;
+ raw.dx = -val;
+ }
+
+ return ds4424_set_value(indio_dev, raw.bits, chan);
+
+ case IIO_CHAN_INFO_PROCESSED: /* val input is picoAmps */
+ /* val can be 0 to 200,000,000 (200 picoAmps) */
+ val0 = val;
+ raw.source_bit = SOURCE_I;
+ if (val < 0) {
+ raw.source_bit = SINK_I;
+ val = -val;
+ }
+ if (val > data->max_picoamp) {
+ pr_err("%s : Requested current %d ", __func__, val);
+ pr_err("exceeds %d picoAmps\n", data->max_picoamp);
+ return -EINVAL;
+ }
+ if (data->rfs_res[chan->channel] < data->min_rfs ||
+ data->rfs_res[chan->channel] > data->max_rfs) {
+ pr_info("%s : Resistor values out of range\n",
+ __func__);
+ return -EINVAL;
+ }
+ val = val / 1000;
+ tmp_scale = data->ifs_scale / 10; /* preserve resolution */
+ val = (val * data->rfs_res[chan->channel]) /
+ tmp_scale;
+ val = (val + 50) / 100;
+ val2 = ((1 << chan->scan_type.realbits) / 2) - 1;
+ if (val > val2) {
+ pr_info("%s : Requested current %d %d",
+ __func__, val0, val);
+ pr_info("exceeds maximum. DAC set to maximum %d\n",
+ val2);
+ val = val2;
+ }
+ raw.dx = val;
+ return ds4424_set_value(indio_dev, raw.bits, chan);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ds4424_verify_chip(struct iio_dev *indio_dev)
+{
+ int ret = 0, val;
+ int i;
+
+ usleep_range(1000, 1200);
+ for (i = 0; i < indio_dev->num_channels; i++) {
+ ret = ds4424_get_value(indio_dev, &val, i);
+ if (ret < 0) {
+ pr_err("%s : read %d, should be 0\n", __func__, ret);
+ break;
+ }
+ }
+ return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int ds4424_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct ds4424_data *data = iio_priv(indio_dev);
+ int ret = 0;
+ u32 i;
+
+ for (i = 0; i < indio_dev->num_channels; i++) {
+ data->save[i] = data->raw[i];
+ ret = ds4424_set_value(indio_dev, 0,
+ &(indio_dev->channels[i]));
+ if (ret < 0)
+ return ret;
+ }
+ return ret;
+}
+
+static int ds4424_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct ds4424_data *data = iio_priv(indio_dev);
+ int ret = 0;
+ u32 i;
+
+ for (i = 0; i < indio_dev->num_channels; i++) {
+ ret = ds4424_set_value(indio_dev, data->save[i],
+ &(indio_dev->channels[i]));
+ if (ret < 0)
+ return ret;
+ }
+ return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(ds4424_pm_ops, ds4424_suspend, ds4424_resume);
+#define DS4424_PM_OPS (&ds4424_pm_ops)
+#else
+#define DS4424_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct iio_info ds4424_info = {
+ .read_raw = ds4424_read_raw,
+ .write_raw = ds4424_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+#ifdef CONFIG_OF
+static int ds4424_parse_dt(struct iio_dev *indio_dev)
+{
+ int ret;
+ int len;
+ int num_ch;
+ int i;
+ int count;
+ struct property *prop;
+ struct ds4424_data *data = iio_priv(indio_dev);
+ struct device_node *node = indio_dev->dev.parent->of_node;
+
+ if (!node) {
+ pr_info("%s:%d ds4424 dts not found\n", __func__, __LINE__);
+ return -ENODEV;
+ }
+
+ prop = of_find_property(node, "rfs-resistors", &len);
+ if (!prop) {
+ pr_err("Invalid rfs-resistor in dt. len: %d\n", len);
+ return -EINVAL;
+ }
+
+ if (len != (DS442X_MAX_DAC_CHANNELS * sizeof(uint32_t))) {
+ pr_err("Invalid rfs-resistor length in dt. len: %d\n", len);
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32_array(node, "rfs-resistors",
+ data->rfs_res, DS442X_MAX_DAC_CHANNELS);
+ if (ret < 0) {
+ pr_err("Reading rfs-resistors from dt failed. ret: %d\n", ret);
+ return ret;
+ }
+
+ pr_info("ds4424 rfs-resistors: %d, %d, %d, %d\n",
+ data->rfs_res[0], data->rfs_res[1],
+ data->rfs_res[2], data->rfs_res[3]);
+
+ ret = of_property_read_u32(node, "max-rfs",
+ &data->max_rfs);
+ if (ret < 0) {
+ pr_err("Reading max-rfs from dt failed. ret: %d\n", ret);
+ return ret;
+ }
+
+ ret = of_property_read_u32(node, "min-rfs",
+ (u32 *)&data->min_rfs);
+ if (ret < 0) {
+ pr_err("Reading min-rfs from dt failed. ret: %d\n", ret);
+ return ret;
+ }
+
+ pr_info("ds4424 max-rfs: %d, min-rfs: %d\n",
+ data->max_rfs, data->min_rfs);
+
+ ret = of_property_read_u32(node, "max-picoamp",
+ (u32 *)&data->max_picoamp);
+ if (ret < 0) {
+ pr_err("Reading max-picoamp from dt failed. ret: %d\n", ret);
+ return ret;
+ }
+
+ ret = of_property_read_u32(node, "ifs-scale",
+ (u32 *)&data->ifs_scale);
+ if (ret < 0) {
+ pr_err("Reading ifs-scale from dt failed. ret: %d\n", ret);
+ return ret;
+ }
+
+ pr_info("ds4424 max-picoamp: %d, ifs-scale: %d\n",
+ data->max_picoamp, data->ifs_scale);
+
+ count = of_property_count_strings(node, "dac-iio-map");
+ if (count < 0) {
+ pr_info("dac-iio-map not found in dts\n");
+ return count;
+ }
+
+ ret = of_property_read_string(node, "vcc-supply", &data->vcc_reg_name);
+ if (ret < 0) {
+ pr_info("DAC vcc-supply is not available in dts\n");
+ data->vcc_reg_name = NULL;
+ }
+
+ if (count != DS4424_MAX_DAC_CHANNELS * 3 &&
+ count != DS4424_MAX_DAC_CHANNELS * 3) {
+ pr_info("Incorrect dac-iio-map in dts. count: %d\n", count);
+ return -EINVAL;
+ }
+
+ num_ch = count / 3;
+ for (i = 0; i < num_ch; i++) {
+ ret = of_property_read_string_index(node,
+ "dac-iio-map", i * 3,
+ &data->dac_iio_map[i].consumer_dev_name);
+ if (ret < 0) {
+ pr_info("%s:%d\n", __func__, __LINE__);
+ return ret;
+ }
+
+ ret = of_property_read_string_index(node, "dac-iio-map",
+ i * 3 + 1,
+ &data->dac_iio_map[i].consumer_channel);
+ if (ret < 0) {
+ pr_info("%s:%d\n", __func__, __LINE__);
+ return ret;
+ }
+
+ ret = of_property_read_string_index(node, "dac-iio-map",
+ i * 3 + 2,
+ &data->dac_iio_map[i].adc_channel_label);
+ if (ret < 0) {
+ pr_info("%s:%d\n", __func__, __LINE__);
+ return ret;
+ }
+
+ pr_info("ds4424 iio-map[%d]: %s, %s, %s\n", i,
+ data->dac_iio_map[i].consumer_dev_name,
+ data->dac_iio_map[i].consumer_channel,
+ data->dac_iio_map[i].adc_channel_label);
+ }
+
+ return 0;
+}
+#else
+static int ds4424_parse_dt(struct iio_dev *indio_dev)
+{
+ return -ENODEV;
+}
+#endif
+
+static int ds4424_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ const struct ds4424_pdata *pdata;
+ struct ds4424_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(&client->dev, "I2C is not supported\n");
+ return -ENODEV;
+ }
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev) {
+ pr_err("%s:%d\n", __func__, __LINE__);
+ return -ENOMEM;
+ }
+
+ data = iio_priv(indio_dev);
+ memset(data, 0, sizeof(*data));
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+ indio_dev->name = id->name;
+ indio_dev->dev.parent = &client->dev;
+
+ ret = ds4424_verify_chip(indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "%s failed. ret:%d\n", __func__, ret);
+ return -ENXIO;
+ }
+
+ if (client->dev.of_node) {
+ ret = ds4424_parse_dt(indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "%s - of_node error\n", __func__);
+ ret = -EINVAL;
+ }
+ } else {
+ pdata = client->dev.platform_data;
+ if (!pdata) {
+ dev_err(&client->dev,
+ "dts/platform data not found.\n");
+ /* Use default driver settings */
+ pdata = &ds4424_pdata_default;
+ }
+
+ pdata = client->dev.platform_data;
+ data->min_rfs = pdata->min_rfs;
+ data->max_rfs = pdata->max_rfs;
+ data->ifs_scale = pdata->ifs_scale;
+ data->max_picoamp = pdata->max_picoamp;
+ data->vcc_reg_name = pdata->vcc_supply_name;
+ memcpy(data->rfs_res, pdata->rfs_res,
+ sizeof(uint32_t) * DS442X_MAX_DAC_CHANNELS);
+ memcpy(data->dac_iio_map, pdata->dac_iio_map,
+ sizeof(struct iio_map) * DS442X_MAX_DAC_CHANNELS);
+ }
+
+ if (data->vcc_reg_name) {
+ data->vcc_reg = devm_regulator_get(&client->dev,
+ data->vcc_reg_name);
+ if (IS_ERR(data->vcc_reg)) {
+ ret = PTR_ERR(data->vcc_reg);
+ dev_err(&client->dev,
+ "Failed to get vcc_reg regulator: %d\n", ret);
+ return ret;
+ }
+ }
+
+ mutex_init(&data->lock);
+ ret = ds4424_regulator_onoff(indio_dev, PWR_ON);
+ if (ret < 0) {
+ pr_err("Unable to turn on the regulator. %s:%d, ret: %d\n",
+ __func__, __LINE__, ret);
+ return ret;
+ }
+
+ switch (id->driver_data) {
+ case ID_DS4422:
+ indio_dev->num_channels = DS4422_MAX_DAC_CHANNELS;
+ break;
+ case ID_DS4424:
+ indio_dev->num_channels = DS4424_MAX_DAC_CHANNELS;
+ break;
+ default:
+ indio_dev->num_channels = DS4424_MAX_DAC_CHANNELS;
+ break;
+ }
+
+ indio_dev->channels = ds4424_channels;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &ds4424_info;
+
+ ret = iio_map_array_register(indio_dev, data->dac_iio_map);
+ if (ret < 0)
+ goto err_iio_device_0;
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0) {
+ pr_err("iio_device_register failed . %s:%d, ret: %d\n",
+ __func__, __LINE__, ret);
+ goto err_iio_device_1;
+ }
+
+ return ret;
+
+err_iio_device_0:
+ ds4424_regulator_onoff(indio_dev, PWR_OFF);
+err_iio_device_1:
+ iio_map_array_unregister(indio_dev);
+ return ret;
+}
+
+static int ds4424_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+ iio_device_unregister(indio_dev);
+ iio_map_array_unregister(indio_dev);
+ ds4424_regulator_onoff(indio_dev, PWR_OFF);
+ return 0;
+}
+
+static const struct i2c_device_id ds4424_id[] = {
+ { "ds4422", ID_DS4422 },
+ { "ds4424", ID_DS4424 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ds4424_id);
+
+static const struct of_device_id ds4424_of_match[] = {
+ { .compatible = "maxim,ds4422" },
+ { .compatible = "maxim,ds4424" },
+ { }
+};
+
+MODULE_DEVICE_TABLE(of, ds4424_of_match);
+
+static struct i2c_driver ds4424_driver = {
+ .driver = {
+ .name = "ds4424",
+ .pm = DS4424_PM_OPS,
+ },
+ .probe = ds4424_probe,
+ .remove = ds4424_remove,
+ .id_table = ds4424_id,
+};
+module_i2c_driver(ds4424_driver);
+
+MODULE_DESCRIPTION("Maxim DS4424 DAC Driver");
+MODULE_AUTHOR("Ismail H. Kose <ismail.kose@maximintegrated.com>");
+MODULE_AUTHOR("Vishal Sood <vishal.sood@maximintegrated.com>");
+MODULE_AUTHOR("David Jung <david.jung@maximintegrated.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/iio/dac/ds4424.h b/include/linux/iio/dac/ds4424.h
new file mode 100644
index 000000000000..09ff3d61797d
--- /dev/null
+++ b/include/linux/iio/dac/ds4424.h
@@ -0,0 +1,29 @@
+/*
+ * Maxim Integrated
+ * 7-bit, Multi-Channel Sink/Source Current DAC Driver
+ * Copyright (C) 2017 Maxim Integrated
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef IIO_DAC_DS4424_H_
+#define IIO_DAC_DS4424_H_
+#include <linux/iio/iio.h>
+#include <linux/iio/machine.h>
+
+#define DS4422_MAX_DAC_CHANNELS 2
+#define DS4424_MAX_DAC_CHANNELS 4
+#define DS442X_MAX_DAC_CHANNELS DS4424_MAX_DAC_CHANNELS
+
+struct ds4424_pdata {
+ const char *vcc_supply_name;
+ uint32_t max_rfs;
+ uint32_t min_rfs;
+ uint32_t ifs_scale;
+ uint32_t max_picoamp;
+ uint32_t rfs_res[DS442X_MAX_DAC_CHANNELS];
+ struct iio_map dac_iio_map[DS442X_MAX_DAC_CHANNELS + 1];
+};
+#endif /* IIO_DAC_DS4424_H_ */
--
2.11.0
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