diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2017-07-29 01:20:14 +0300 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2017-08-20 17:41:11 +0300 |
| commit | 8cfa26a77cfcad888f44c0ed902fe6c7c73783fe (patch) | |
| tree | 73b0a173d60e77ccaa0e4eac3d9904bbecfd209e /drivers/iio | |
| parent | 0a60340f199136e7b74f4b279e3844abf2d45485 (diff) | |
| download | linux-8cfa26a77cfcad888f44c0ed902fe6c7c73783fe.tar.xz | |
iio: adc: ti-ads7950: Allow to use on ACPI platforms
ACPI enabled platforms do not have a mean of regulators. Instead we use
hard coded voltage value for reference pin. When value is 0 (default) we
fall back to request a regulator.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/adc/ti-ads7950.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c index 26b980a1604b..a376190914ad 100644 --- a/drivers/iio/adc/ti-ads7950.c +++ b/drivers/iio/adc/ti-ads7950.c @@ -21,6 +21,7 @@ * GNU General Public License for more details. */ +#include <linux/acpi.h> #include <linux/bitops.h> #include <linux/device.h> #include <linux/err.h> @@ -37,6 +38,12 @@ #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> +/* + * In case of ACPI, we use the 5000 mV as default for the reference pin. + * Device tree users encode that via the vref-supply regulator. + */ +#define TI_ADS7950_VA_MV_ACPI_DEFAULT 5000 + #define TI_ADS7950_CR_MANUAL BIT(12) #define TI_ADS7950_CR_WRITE BIT(11) #define TI_ADS7950_CR_CHAN(ch) ((ch) << 7) @@ -58,6 +65,7 @@ struct ti_ads7950_state { struct spi_message scan_single_msg; struct regulator *reg; + unsigned int vref_mv; unsigned int settings; @@ -305,11 +313,15 @@ static int ti_ads7950_get_range(struct ti_ads7950_state *st) { int vref; - vref = regulator_get_voltage(st->reg); - if (vref < 0) - return vref; + if (st->vref_mv) { + vref = st->vref_mv; + } else { + vref = regulator_get_voltage(st->reg); + if (vref < 0) + return vref; - vref /= 1000; + vref /= 1000; + } if (st->settings & TI_ADS7950_CR_RANGE_5V) vref *= 2; @@ -411,6 +423,10 @@ static int ti_ads7950_probe(struct spi_device *spi) spi_message_init_with_transfers(&st->scan_single_msg, st->scan_single_xfer, 3); + /* Use hard coded value for reference voltage in ACPI case */ + if (ACPI_COMPANION(&spi->dev)) + st->vref_mv = TI_ADS7950_VA_MV_ACPI_DEFAULT; + st->reg = devm_regulator_get(&spi->dev, "vref"); if (IS_ERR(st->reg)) { dev_err(&spi->dev, "Failed get get regulator \"vref\"\n"); |