Add platform_data for the driver which allows to specify whether an external
reference voltage is used or not. It is not possible to use the return value of
regulator_get() for this since the regulator framework is able to return a dummy
regulator in case no regulator has been specified. In this case the driver will
always get a valid regulator, no matter if it has been specified or not. Also
make the regulator non-optional if platform_data states that an external
reference voltage should be used.
Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
---
drivers/staging/iio/adc/ad7291.c | 38 +++++++++++++++++++++++---------------
drivers/staging/iio/adc/ad7291.h | 12 ++++++++++++
2 files changed, 35 insertions(+), 15 deletions(-)
create mode 100644 drivers/staging/iio/adc/ad7291.h
diff --git a/drivers/staging/iio/adc/ad7291.c b/drivers/staging/iio/adc/ad7291.c
index c2709d6..3fc79e5 100644
--- a/drivers/staging/iio/adc/ad7291.c
+++ b/drivers/staging/iio/adc/ad7291.c
@@ -21,6 +21,8 @@
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
+#include "ad7291.h"
+
/*
* Simplified handling
*
@@ -76,7 +78,6 @@
struct ad7291_chip_info {
struct i2c_client *client;
struct regulator *reg;
- u16 int_vref_mv;
u16 command;
u16 c_mask; /* Active voltage channels for events */
struct mutex state_lock;
@@ -445,7 +446,15 @@ static int ad7291_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_VOLTAGE:
- *val = chip->int_vref_mv;
+ if (chip->reg) {
+ int vref;
+ vref = regulator_get_voltage(chip->reg);
+ if (vref < 0)
+ return vref;
+ *val = vref / 1000;
+ } else {
+ *val = 2500;
+ }
*val2 = AD7291_BITS;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_TEMP:
@@ -513,9 +522,10 @@ static const struct iio_info ad7291_info = {
static int ad7291_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
+ struct ad7291_platform_data *pdata = client->dev.platform_data;
struct ad7291_chip_info *chip;
struct iio_dev *indio_dev;
- int ret = 0, voltage_uv = 0;
+ int ret = 0;
indio_dev = iio_device_alloc(sizeof(*chip));
if (indio_dev == NULL) {
@@ -524,12 +534,14 @@ static int ad7291_probe(struct i2c_client *client,
}
chip = iio_priv(indio_dev);
- chip->reg = regulator_get(&client->dev, "vcc");
- if (!IS_ERR(chip->reg)) {
+ if (pdata && pdata->use_external_ref) {
+ chip->reg = regulator_get(&client->dev, "vref");
+ if (IS_ERR(chip->reg))
+ goto error_free;
+
ret = regulator_enable(chip->reg);
if (ret)
goto error_put_reg;
- voltage_uv = regulator_get_voltage(chip->reg);
}
mutex_init(&chip->state_lock);
@@ -542,12 +554,8 @@ static int ad7291_probe(struct i2c_client *client,
AD7291_T_SENSE_MASK | /* Tsense always enabled */
AD7291_ALERT_POLARITY; /* set irq polarity low level */
- if (voltage_uv) {
- chip->int_vref_mv = voltage_uv / 1000;
+ if (pdata && pdata->use_external_ref)
chip->command |= AD7291_EXT_REF;
- } else {
- chip->int_vref_mv = 2500; /* Build-in ref */
- }
indio_dev->name = id->name;
indio_dev->channels = ad7291_channels;
@@ -590,12 +598,12 @@ error_unreg_irq:
if (client->irq)
free_irq(client->irq, indio_dev);
error_disable_reg:
- if (!IS_ERR(chip->reg))
+ if (chip->reg)
regulator_disable(chip->reg);
error_put_reg:
- if (!IS_ERR(chip->reg))
+ if (chip->reg)
regulator_put(chip->reg);
-
+error_free:
iio_device_free(indio_dev);
error_ret:
return ret;
@@ -611,7 +619,7 @@ static int ad7291_remove(struct i2c_client *client)
if (client->irq)
free_irq(client->irq, indio_dev);
- if (!IS_ERR(chip->reg)) {
+ if (chip->reg) {
regulator_disable(chip->reg);
regulator_put(chip->reg);
}
diff --git a/drivers/staging/iio/adc/ad7291.h b/drivers/staging/iio/adc/ad7291.h
new file mode 100644
index 0000000..bbd89fa
--- /dev/null
+++ b/drivers/staging/iio/adc/ad7291.h
@@ -0,0 +1,12 @@
+#ifndef __IIO_AD7291_H__
+#define __IIO_AD7291_H__
+
+/**
+ * struct ad7291_platform_data - AD7291 platform data
+ * @use_external_ref: Whether to use an external or internal reference voltage
+ */
+struct ad7291_platform_data {
+ bool use_external_ref;
+};
+
+#endif
--
1.8.0
--
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