iio: add powerdown to mcp4725 dac drive
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
index cb9db90..f569738 100644
--- a/drivers/iio/dac/mcp4725.c
+++ b/drivers/iio/dac/mcp4725.c
@@ -31,15 +31,19 @@
struct i2c_client *client;
u16 vref_mv;
u16 dac_value;
+ bool powerdown;
+ unsigned powerdown_mode;
};
-#ifdef CONFIG_PM_SLEEP
static int mcp4725_suspend(struct device *dev)
{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mcp4725_data *data = iio_priv(indio_dev);
u8 outbuf[2];
- outbuf[0] = 0x3 << 4; /* power-down bits, 500 kOhm resistor */
+ outbuf[0] = (data->powerdown_mode + 1) << 4;
outbuf[1] = 0;
+ data->powerdown = true;
return i2c_master_send(to_i2c_client(dev), outbuf, 2);
}
@@ -53,10 +57,12 @@
/* restore previous DAC value */
outbuf[0] = (data->dac_value >> 8) & 0xf;
outbuf[1] = data->dac_value & 0xff;
+ data->powerdown = false;
return i2c_master_send(to_i2c_client(dev), outbuf, 2);
}
+#ifdef CONFIG_PM_SLEEP
static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
#define MCP4725_PM_OPS (&mcp4725_pm_ops)
#else
@@ -123,6 +129,78 @@
.attrs = mcp4725_attributes,
};
+static const char * const mcp4725_powerdown_modes[] = {
+ "1kohm_to_gnd",
+ "100kohm_to_gnd",
+ "500kohm_to_gnd"
+};
+
+static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct mcp4725_data *data = iio_priv(indio_dev);
+
+ return data->powerdown_mode;
+}
+
+static int mcp4725_set_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, unsigned mode)
+{
+ struct mcp4725_data *data = iio_priv(indio_dev);
+
+ data->powerdown_mode = mode;
+
+ return 0;
+}
+
+static ssize_t mcp4725_read_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private, const struct iio_chan_spec *chan, char *buf)
+{
+ struct mcp4725_data *data = iio_priv(indio_dev);
+
+ return sprintf(buf, "%d\n", data->powerdown);
+}
+
+static ssize_t mcp4725_write_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private, const struct iio_chan_spec *chan,
+ const char *buf, size_t len)
+{
+ struct mcp4725_data *data = iio_priv(indio_dev);
+ bool state;
+ int ret;
+
+ ret = strtobool(buf, &state);
+ if (ret)
+ return ret;
+
+ if (state)
+ ret = mcp4725_suspend(&data->client->dev);
+ else
+ ret = mcp4725_resume(&data->client->dev);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static const struct iio_enum mcp4725_powerdown_mode_enum = {
+ .items = mcp4725_powerdown_modes,
+ .num_items = ARRAY_SIZE(mcp4725_powerdown_modes),
+ .get = mcp4725_get_powerdown_mode,
+ .set = mcp4725_set_powerdown_mode,
+};
+
+static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
+ {
+ .name = "powerdown",
+ .read = mcp4725_read_powerdown,
+ .write = mcp4725_write_powerdown,
+ },
+ IIO_ENUM("powerdown_mode", false, &mcp4725_powerdown_mode_enum),
+ IIO_ENUM_AVAILABLE("powerdown_mode", &mcp4725_powerdown_mode_enum),
+ { },
+};
+
static const struct iio_chan_spec mcp4725_channel = {
.type = IIO_VOLTAGE,
.indexed = 1,
@@ -131,6 +209,7 @@
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.scan_type = IIO_ST('u', 12, 16, 0),
+ .ext_info = mcp4725_ext_info,
};
static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
@@ -208,6 +287,7 @@
struct iio_dev *indio_dev;
struct mcp4725_platform_data *platform_data = client->dev.platform_data;
u8 inbuf[3];
+ u8 pd;
int err;
if (!platform_data || !platform_data->vref_mv) {
@@ -239,6 +319,9 @@
dev_err(&client->dev, "failed to read DAC value");
goto exit_free_device;
}
+ pd = (inbuf[0] >> 1) & 0x3;
+ data->powerdown = pd > 0 ? true : false;
+ data->powerdown_mode = pd ? pd-1 : 2; /* 500kohm_to_gnd */
data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
err = iio_device_register(indio_dev);