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@xxxxxxxxxxxxxxx>
---
drivers/iio/adc/ti-ads7950.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c
index 16a06633332c..ab669af291b7 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");
--
2.13.2
--
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