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iio: add powerdown to mcp4725 dac drive 

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Peter Meerwald 2013-06-23 22:30:00 +01:00 committed by Jonathan Cameron
parent f17b77d6cf
commit 155f1b4189
1 changed files with 85 additions and 2 deletions
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87
drivers/iio/dac/mcp4725.c
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@ -31,15 +31,19 @@ struct mcp4725_data {
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 @@ static int mcp4725_resume(struct device *dev)
/* 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 @@ static const struct attribute_group mcp4725_attribute_group = {
.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 @@ static const struct iio_chan_spec mcp4725_channel = {
.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 @@ static int mcp4725_probe(struct i2c_client *client,
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 @@ static int mcp4725_probe(struct i2c_client *client,
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);