diff options
author | Peter Meerwald <pmeerw@pmeerw.net> | 2013-06-23 21:30:00 (GMT) |
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committer | Jonathan Cameron <jic23@kernel.org> | 2013-08-03 17:40:31 (GMT) |
commit | 155f1b4189d093b1e7c09d90e660dba774dc325a (patch) | |
tree | c200e8f06ea9737dabca3c7965b76c04907321bf /drivers/iio/dac | |
parent | f17b77d6cfbc0d130ba9d57b89e8579ff43a3350 (diff) | |
download | linux-fsl-qoriq-155f1b4189d093b1e7c09d90e660dba774dc325a.tar.xz |
iio: add powerdown to mcp4725 dac drive
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/dac')
-rw-r--r-- | drivers/iio/dac/mcp4725.c | 87 |
1 files changed, 85 insertions, 2 deletions
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 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); |