[PATCH 4.15 074/128] iio: health: max30102: Add power enable parameter to get_temp function

From: Greg Kroah-Hartman
Date: Fri Mar 16 2018 - 11:42:37 EST


4.15-stable review patch. If anyone has any objections, please let me know.

------------------

From: Peter Meerwald-Stadler <pmeerw@xxxxxxxxxx>


[ Upstream commit a9c47abbdd71dceeaf1b923e5ce10e700e036905 ]

Chip must not be in shutdown for reading temperature, so briefly leave
shutdown if buffer is not already running

Signed-off-by: Peter Meerwald-Stadler <pmeerw@xxxxxxxxxx>
Acked-by: Matt Ranostay <matt.ranostay@xxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iio/health/max30102.c | 36 +++++++++++++++++++++++-------------
1 file changed, 23 insertions(+), 13 deletions(-)

--- a/drivers/iio/health/max30102.c
+++ b/drivers/iio/health/max30102.c
@@ -329,20 +329,31 @@ static int max30102_read_temp(struct max
return 0;
}

-static int max30102_get_temp(struct max30102_data *data, int *val)
+static int max30102_get_temp(struct max30102_data *data, int *val, bool en)
{
int ret;

+ if (en) {
+ ret = max30102_set_powermode(data, true);
+ if (ret)
+ return ret;
+ }
+
/* start acquisition */
ret = regmap_update_bits(data->regmap, MAX30102_REG_TEMP_CONFIG,
MAX30102_REG_TEMP_CONFIG_TEMP_EN,
MAX30102_REG_TEMP_CONFIG_TEMP_EN);
if (ret)
- return ret;
+ goto out;

msleep(35);
+ ret = max30102_read_temp(data, val);
+
+out:
+ if (en)
+ max30102_set_powermode(data, false);

- return max30102_read_temp(data, val);
+ return ret;
}

static int max30102_read_raw(struct iio_dev *indio_dev,
@@ -355,20 +366,19 @@ static int max30102_read_raw(struct iio_
switch (mask) {
case IIO_CHAN_INFO_RAW:
/*
- * Temperature reading can only be acquired while engine
- * is running
+ * Temperature reading can only be acquired when not in
+ * shutdown; leave shutdown briefly when buffer not running
*/
mutex_lock(&indio_dev->mlock);
-
if (!iio_buffer_enabled(indio_dev))
- ret = -EBUSY;
- else {
- ret = max30102_get_temp(data, val);
- if (!ret)
- ret = IIO_VAL_INT;
- }
-
+ ret = max30102_get_temp(data, val, true);
+ else
+ ret = max30102_get_temp(data, val, false);
mutex_unlock(&indio_dev->mlock);
+ if (ret)
+ return ret;
+
+ ret = IIO_VAL_INT;
break;
case IIO_CHAN_INFO_SCALE:
*val = 1000; /* 62.5 */