---
.../devicetree/bindings/iio/dac/max5821.txt | 14 +
drivers/iio/dac/Kconfig | 8 +
drivers/iio/dac/Makefile | 1 +
drivers/iio/dac/max5821.c | 405 ++++++++++++++++++++
4 files changed, 428 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/iio/dac/max5821.txt
create mode 100644 drivers/iio/dac/max5821.c
Changelog:
v3: (thanks Jonathan Cameron for the feedback)
- use iio_device_register
v2: (thanks Peter Meerwald, Antonio Borneo and Jonathan Cameron for the feedback)
- use devm_iio_device_register
- use regulator
- add locking when reading a register
- use array instead of switch for dac command
- use ARRAY_SIZE instead of hardcode num of channels
- set name
- some others little fix
diff --git a/Documentation/devicetree/bindings/iio/dac/max5821.txt b/Documentation/devicetree/bindings/iio/dac/max5821.txt
new file mode 100644
index 0000000..54276ce
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/max5821.txt
@@ -0,0 +1,14 @@
+Maxim max5821 DAC device driver
+
+Required properties:
+ - compatible: Must be "maxim,max5821"
+ - reg: Should contain the DAC I2C address
+ - vref-supply: Phandle to the vref power supply
+
+Example:
+
+ max5821@38 {
+ compatible = "maxim,max5821";
+ reg = <0x38>;
+ vref-supply = <®_max5821>;
+ };
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index f378ca8..fd14a72 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -152,6 +152,14 @@ config MAX517
This driver can also be built as a module. If so, the module
will be called max517.
+config MAX5821
+ tristate "Maxim MAX5821 DAC driver"
+ depends on I2C
+ depends on OF
+ help
+ Say yes here to build support for Maxim MAX5821
+ 10 bits DAC.
+
config MCP4725
tristate "MCP4725 DAC driver"
depends on I2C
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index bb84ad6..82545c0 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -17,4 +17,5 @@ obj-$(CONFIG_AD5791) += ad5791.o
obj-$(CONFIG_AD5686) += ad5686.o
obj-$(CONFIG_AD7303) += ad7303.o
obj-$(CONFIG_MAX517) += max517.o
+obj-$(CONFIG_MAX5821) += max5821.o
obj-$(CONFIG_MCP4725) += mcp4725.o
diff --git a/drivers/iio/dac/max5821.c b/drivers/iio/dac/max5821.c
new file mode 100644
index 0000000..6e91449
--- /dev/null
+++ b/drivers/iio/dac/max5821.c
@@ -0,0 +1,405 @@
+ /*
+ * iio/dac/max5821.c
+ * Copyright (C) 2014 Philippe Reynes
+ *
+ * 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/iio/iio.h>
+#include <linux/regulator/consumer.h>
+
+#define MAX5821_MAX_DAC_CHANNELS 2
+
+/* command bytes */
+#define MAX5821_LOAD_DAC_A_IN_REG_B 0x00
+#define MAX5821_LOAD_DAC_B_IN_REG_A 0x10
+#define MAX5821_EXTENDED_COMMAND_MODE 0xf0
+#define MAX5821_READ_DAC_A_COMMAND 0xf1
+#define MAX5821_READ_DAC_B_COMMAND 0xf2
+
+#define MAX5821_EXTENDED_POWER_UP 0x00
+#define MAX5821_EXTENDED_POWER_DOWN_MODE0 0x01
+#define MAX5821_EXTENDED_POWER_DOWN_MODE1 0x02
+#define MAX5821_EXTENDED_POWER_DOWN_MODE2 0x03
+#define MAX5821_EXTENDED_DAC_A 0x04
+#define MAX5821_EXTENDED_DAC_B 0x08
+
+enum max5821_device_ids {
+ ID_MAX5821,
+};
+
+struct max5821_data {
+ struct i2c_client *client;
+ struct regulator *vref_reg;
+ unsigned short vref_mv;
+ bool powerdown[MAX5821_MAX_DAC_CHANNELS];
+ u8 powerdown_mode[MAX5821_MAX_DAC_CHANNELS];
+ struct mutex lock;
+};
+
+static const char * const max5821_powerdown_modes[] = {
+ "three_state",
+ "1kohm_to_gnd",
+ "100kohm_to_gnd",
+};
+
+enum {
+ MAX5821_THREE_STATE,
+ MAX5821_1KOHM_TO_GND,
+ MAX5821_100KOHM_TO_GND
+};
+
+static int max5821_get_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct max5821_data *st = iio_priv(indio_dev);
+
+ return st->powerdown_mode[chan->channel];
+}
+
+static int max5821_set_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ unsigned int mode)
+{
+ struct max5821_data *st = iio_priv(indio_dev);
+
+ st->powerdown_mode[chan->channel] = mode;
+
+ return 0;
+}
+
+static const struct iio_enum max5821_powerdown_mode_enum = {
+ .items = max5821_powerdown_modes,
+ .num_items = ARRAY_SIZE(max5821_powerdown_modes),
+ .get = max5821_get_powerdown_mode,
+ .set = max5821_set_powerdown_mode,
+};
+
+static ssize_t max5821_read_dac_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ char *buf)
+{
+ struct max5821_data *st = iio_priv(indio_dev);
+
+ return sprintf(buf, "%d\n", st->powerdown[chan->channel]);
+}
+
+static int max5821_sync_powerdown_mode(struct max5821_data *data,
+ const struct iio_chan_spec *chan)
+{
+ u8 outbuf[2];
+
+ outbuf[0] = MAX5821_EXTENDED_COMMAND_MODE;
+
+ if (chan->channel == 0)
+ outbuf[1] = MAX5821_EXTENDED_DAC_A;
+ else
+ outbuf[1] = MAX5821_EXTENDED_DAC_B;
+
+ if (data->powerdown[chan->channel])
+ outbuf[1] |= data->powerdown_mode[chan->channel] + 1;
+ else
+ outbuf[1] |= MAX5821_EXTENDED_POWER_UP;
+
+ return i2c_master_send(data->client, outbuf, 2);
+}
+
+static ssize_t max5821_write_dac_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ const char *buf, size_t len)
+{
+ struct max5821_data *data = iio_priv(indio_dev);
+ bool powerdown;
+ int ret;
+
+ ret = strtobool(buf, &powerdown);
+ if (ret)
+ return ret;
+
+ data->powerdown[chan->channel] = powerdown;
+
+ ret = max5821_sync_powerdown_mode(data, chan);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static const struct iio_chan_spec_ext_info max5821_ext_info[] = {
+ {
+ .name = "powerdown",
+ .read = max5821_read_dac_powerdown,
+ .write = max5821_write_dac_powerdown,
+ .shared = IIO_SEPARATE,
+ },
+ IIO_ENUM("powerdown_mode", IIO_SEPARATE, &max5821_powerdown_mode_enum),
+ IIO_ENUM_AVAILABLE("powerdown_mode", &max5821_powerdown_mode_enum),
+ { },
+};
+
+#define MAX5821_CHANNEL(chan) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = (chan), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE), \
+ .ext_info = max5821_ext_info, \
+}
+
+static const struct iio_chan_spec max5821_channels[] = {
+ MAX5821_CHANNEL(0),
+ MAX5821_CHANNEL(1)
+};
+
+static const u8 max5821_read_dac_command[] = {
+ MAX5821_READ_DAC_A_COMMAND,
+ MAX5821_READ_DAC_B_COMMAND
+};
+
+static const u8 max5821_load_dac_command[] = {
+ MAX5821_LOAD_DAC_A_IN_REG_B,
+ MAX5821_LOAD_DAC_B_IN_REG_A
+};
+
+static int max5821_get_value(struct iio_dev *indio_dev,
+ int *val, int channel)
+{
+ struct max5821_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ u8 outbuf[1];
+ u8 inbuf[2];
+ int ret;
+
+ if ((channel != 0) && (channel != 1))
+ return -EINVAL;
+
+ outbuf[0] = max5821_read_dac_command[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, 2);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ return ret;
+ } else if (ret != 2) {
+ mutex_unlock(&data->lock);
+ return -EIO;
+ }
+
+ mutex_unlock(&data->lock);
+
+ *val = ((inbuf[0] & 0x0f) << 6) | (inbuf[1] >> 2);
+
+ return IIO_VAL_INT;
+}
+
+static int max5821_set_value(struct iio_dev *indio_dev,
+ int val, int channel)
+{
+ struct max5821_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ u8 outbuf[2];
+ int ret;
+
+ if ((val < 0) || (val > 1023))
+ return -EINVAL;
+
+ if ((channel != 0) && (channel != 1))
+ return -EINVAL;
+
+ outbuf[0] = max5821_load_dac_command[channel];
+ outbuf[0] |= val >> 6;
+ outbuf[1] = (val & 0x3f) << 2;
+
+ ret = i2c_master_send(client, outbuf, 2);
+ if (ret < 0)
+ return ret;
+ else if (ret != 2)
+ return -EIO;
+ else
+ return 0;
+}
+
+static int max5821_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct max5821_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ return max5821_get_value(indio_dev, val, chan->channel);
+ case IIO_CHAN_INFO_SCALE:
+ *val = data->vref_mv;
+ *val2 = 10;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int max5821_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ if (val2 != 0)
+ return -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ return max5821_set_value(indio_dev, val, chan->channel);
+ default:
+ return -EINVAL;
+ }
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int max5821_suspend(struct device *dev)
+{
+ u8 outbuf[2] = { MAX5821_EXTENDED_COMMAND_MODE,
+ MAX5821_EXTENDED_DAC_A |
+ MAX5821_EXTENDED_DAC_B |
+ MAX5821_EXTENDED_POWER_DOWN_MODE2 };
+
+ return i2c_master_send(to_i2c_client(dev), outbuf, 2);
+}
+
+static int max5821_resume(struct device *dev)
+{
+ u8 outbuf[2] = { MAX5821_EXTENDED_COMMAND_MODE,
+ MAX5821_EXTENDED_DAC_A |
+ MAX5821_EXTENDED_DAC_B |
+ MAX5821_EXTENDED_POWER_UP };
+
+ return i2c_master_send(to_i2c_client(dev), outbuf, 2);
+}
+
+static SIMPLE_DEV_PM_OPS(max5821_pm_ops, max5821_suspend, max5821_resume);
+#define MAX5821_PM_OPS (&max5821_pm_ops)
+#else
+#define MAX5821_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct iio_info max5821_info = {
+ .read_raw = max5821_read_raw,
+ .write_raw = max5821_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static int max5821_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct max5821_data *data;
+ struct iio_dev *indio_dev;
+ u32 tmp;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+ mutex_init(&data->lock);
+
+ /* max5821 start in powerdown mode 100Kohm to ground */
+ for (tmp = 0; tmp < MAX5821_MAX_DAC_CHANNELS; tmp++) {
+ data->powerdown[tmp] = true;
+ data->powerdown_mode[tmp] = MAX5821_100KOHM_TO_GND;
+ }
+
+ data->vref_reg = devm_regulator_get(&client->dev, "vref");
+ if (IS_ERR(data->vref_reg)) {
+ ret = PTR_ERR(data->vref_reg);
+ dev_err(&client->dev,
+ "Failed to get vref regulator: %d\n", ret);
+ goto error_free_reg;
+ }
+
+ ret = regulator_enable(data->vref_reg);
+ if (ret) {
+ dev_err(&client->dev,
+ "Failed to enable vref regulator: %d\n", ret);
+ goto error_free_reg;
+ }
+
+ ret = regulator_get_voltage(data->vref_reg);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "Failed to get voltage on regulator: %d\n", ret);
+ goto error_disable_reg;
+ }
+
+ data->vref_mv = ret / 1000;
+
+ indio_dev->name = id->name;
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->num_channels = ARRAY_SIZE(max5821_channels);
+ indio_dev->channels = max5821_channels;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &max5821_info;
+
+ return iio_device_register(indio_dev);
+
+error_disable_reg:
+ regulator_disable(data->vref_reg);
+
+error_free_reg:
+
+ return ret;
+}
+
+static int max5821_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct max5821_data *data = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ regulator_disable(data->vref_reg);
+
+ return 0;
+}
+
+static const struct i2c_device_id max5821_id[] = {
+ { "max5821", ID_MAX5821 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max5821_id);
+
+static const struct of_device_id max5821_of_match[] = {
+ { .compatible = "maxim,max5821" },
+ { }
+};
+
+static struct i2c_driver max5821_driver = {
+ .driver = {
+ .name = "max5821",
+ .pm = MAX5821_PM_OPS,
+ .owner = THIS_MODULE,
+ },
+ .probe = max5821_probe,
+ .remove = max5821_remove,
+ .id_table = max5821_id,
+};
+module_i2c_driver(max5821_driver);
+
+MODULE_AUTHOR("Philippe Reynes <tremyfr@xxxxxxxx>");
+MODULE_DESCRIPTION("MAX5821 DAC");
+MODULE_LICENSE("GPL v2");
