m62332 is a simple 2-channel DAC used on several Sharp Zaurus boards to
control LCD voltage, backlight and sound. The driver use regulators to
control the reference voltage and enabling/disabling the DAC.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
---
Changes since v3:
* Use IIO_CHAN_INFO_OFFSET to represent DAC output more precisely
* Handle regulator_get_voltage() error
* Minor changes in m62332_set_value()
drivers/iio/dac/Kconfig | 10 ++
drivers/iio/dac/Makefile | 1 +
drivers/iio/dac/m62332.c | 269 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 280 insertions(+)
create mode 100644 drivers/iio/dac/m62332.c
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 13471a7..e701e28 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -142,6 +142,16 @@ config AD7303
To compile this driver as module choose M here: the module will be called
ad7303.
+config M62332
+ tristate "Mitsubishi M62332 DAC driver"
+ depends on I2C
+ help
+ If you say yes here you get support for the Mitsubishi M62332
+ (I2C 8-Bit DACs with rail-to-rail outputs).
+
+ This driver can also be built as a module. If so, the module
+ will be called m62332.
+
config MAX517
tristate "Maxim MAX517/518/519/520/521 DAC driver"
depends on I2C
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 52be7e1..63ae056 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_AD5764) += ad5764.o
obj-$(CONFIG_AD5791) += ad5791.o
obj-$(CONFIG_AD5686) += ad5686.o
obj-$(CONFIG_AD7303) += ad7303.o
+obj-$(CONFIG_M62332) += m62332.o
obj-$(CONFIG_MAX517) += max517.o
obj-$(CONFIG_MAX5821) += max5821.o
obj-$(CONFIG_MCP4725) += mcp4725.o
diff --git a/drivers/iio/dac/m62332.c b/drivers/iio/dac/m62332.c
new file mode 100644
index 0000000..c23d7fa
--- /dev/null
+++ b/drivers/iio/dac/m62332.c
@@ -0,0 +1,269 @@
+/*
+ * m62332.c - Support for Mitsubishi m62332 DAC
+ *
+ * Copyright (c) 2014 Dmitry Eremin-Solenikov
+ *
+ * Based on max517 driver:
+ * Copyright (C) 2010, 2011 Roland Stigge <stigge@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+
+#include <linux/regulator/consumer.h>
+
+#define M62332_CHANNELS 2
+
+struct m62332_data {
+ struct i2c_client *client;
+ u16 vref_mv;
+ struct regulator *vcc;
+ struct mutex mutex;
+ u8 raw[M62332_CHANNELS];
+#ifdef CONFIG_PM_SLEEP
+ u8 save[M62332_CHANNELS];
+#endif
+};
+
+static int m62332_set_value(struct iio_dev *indio_dev,
+ u8 val, int channel)
+{
+ struct m62332_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ u8 outbuf[2];
+ int res;
+
+ if (val == data->raw[channel])
+ return 0;
+
+ outbuf[0] = channel;
+ outbuf[1] = val;
+
+ mutex_lock(&data->mutex);
+
+ if (val) {
+ res = regulator_enable(data->vcc);
+ if (res)
+ goto out;
+ }
+
+ res = i2c_master_send(client, outbuf, 2);
+ if (res >= 0 && res != 2)
+ res = -EIO;
+ if (res < 0)
+ goto out;
+
+ data->raw[channel] = val;
+
+ if (!val)
+ regulator_disable(data->vcc);
+
+ mutex_unlock(&data->mutex);
+
+ return 0;
+
+out:
+ mutex_unlock(&data->mutex);
+
+ return res;
+}
+
+static int m62332_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long m)
+{
+ struct m62332_data *data = iio_priv(indio_dev);
+
+ switch (m) {
+ case IIO_CHAN_INFO_SCALE:
+ /* Corresponds to Vref / 2^(bits) */
+ *val = data->vref_mv;
+ *val2 = 8;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ case IIO_CHAN_INFO_RAW:
+ *val = data->raw[chan->channel];
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = 1;
+ return IIO_VAL_INT;
+ default:
+ break;
+ }
+ return -EINVAL;
+}
+
+static int m62332_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val, int val2, long mask)
+{
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (val < 0 || val > 255)
+ return -EINVAL;
+
+ ret = m62332_set_value(indio_dev, val, chan->channel);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int m62332_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct m62332_data *data = iio_priv(indio_dev);
+ int ret;
+
+ data->save[0] = data->raw[0];
+ data->save[1] = data->raw[1];
+
+ ret = m62332_set_value(indio_dev, 0, 0);
+ if (ret < 0)
+ return ret;
+
+ return m62332_set_value(indio_dev, 0, 1);
+}
+
+static int m62332_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct m62332_data *data = iio_priv(indio_dev);
+ int ret;
+
+ ret = m62332_set_value(indio_dev, data->save[0], 0);
+ if (ret < 0)
+ return ret;
+
+ return m62332_set_value(indio_dev, data->save[1], 1);
+}
+
+static SIMPLE_DEV_PM_OPS(m62332_pm_ops, m62332_suspend, m62332_resume);
+#define M62332_PM_OPS (&m62332_pm_ops)
+#else
+#define M62332_PM_OPS NULL
+#endif
+
+static const struct iio_info m62332_info = {
+ .read_raw = m62332_read_raw,
+ .write_raw = m62332_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+#define M62332_CHANNEL(chan) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = (chan), \
+ .datasheet_name = "CH" #chan, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_OFFSET), \
+}
+
+static const struct iio_chan_spec m62332_channels[M62332_CHANNELS] = {
+ M62332_CHANNEL(0),
+ M62332_CHANNEL(1)
+};
+
+static int m62332_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct m62332_data *data;
+ struct iio_dev *indio_dev;
+ 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->mutex);
+
+ data->vcc = devm_regulator_get(&client->dev, "VCC");
+ if (IS_ERR(data->vcc))
+ return PTR_ERR(data->vcc);
+
+ /* establish that the iio_dev is a child of the i2c device */
+ indio_dev->dev.parent = &client->dev;
+
+ indio_dev->num_channels = M62332_CHANNELS;
+ indio_dev->channels = m62332_channels;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &m62332_info;
+
+ ret = regulator_get_voltage(data->vcc);
+ if (ret < 0)
+ return ret;
+ data->vref_mv = ret / 1000; /* mV */
+
+ ret = iio_map_array_register(indio_dev, client->dev.platform_data);
+ if (ret < 0)
+ return ret;
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0)
+ goto err;
+
+ return 0;
+
+err:
+ iio_map_array_unregister(indio_dev);
+ return ret;
+}
+
+static int m62332_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);
+
+ return 0;
+}
+
+static const struct i2c_device_id m62332_id[] = {
+ { "m62332", },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, m62332_id);
+
+static struct i2c_driver m62332_driver = {
+ .driver = {
+ .name = "m62332",
+ .pm = M62332_PM_OPS,
+ },
+ .probe = m62332_probe,
+ .remove = m62332_remove,
+ .id_table = m62332_id,
+};
+module_i2c_driver(m62332_driver);
+
+MODULE_AUTHOR("Dmitry Eremin-Solenikov");
+MODULE_DESCRIPTION("M62332 8-bit DAC");
+MODULE_LICENSE("GPL v2");
--
2.1.4
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