Without this patch, the SHT15 driver may fail silently with a
non-bidirectional data line and/or an input-only clock line. The patch
checks the return value of gpio_direction_* function calls, prints an
error message for void-returning functions or returns the corresponding
error code otherwise.
Signed-off-by: Vivien Didelot <vivien.dide...@savoirfairelinux.com>
---
drivers/hwmon/sht15.c | 43 ++++++++++++++++++++++++++++++++++---------
1 file changed, 34 insertions(+), 9 deletions(-)
diff --git a/drivers/hwmon/sht15.c b/drivers/hwmon/sht15.c
index 9a594e6..10b078c 100644
--- a/drivers/hwmon/sht15.c
+++ b/drivers/hwmon/sht15.c
@@ -216,7 +216,10 @@ static void sht15_connection_reset(struct sht15_data *data)
{
int i;
- gpio_direction_output(data->pdata->gpio_data, 1);
+ if (gpio_direction_output(data->pdata->gpio_data, 1)) {
+ dev_err(data->dev, "failed to set data line direction to
output\n");
+ return;
+ }
ndelay(SHT15_TSCKL);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
@@ -254,7 +257,10 @@ static inline void sht15_send_bit(struct sht15_data *data,
int val)
static void sht15_transmission_start(struct sht15_data *data)
{
/* ensure data is high and output */
- gpio_direction_output(data->pdata->gpio_data, 1);
+ if (gpio_direction_output(data->pdata->gpio_data, 1)) {
+ dev_err(data->dev, "failed to set data line direction to
output\n");
+ return;
+ }
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
@@ -293,7 +299,11 @@ static void sht15_send_byte(struct sht15_data *data, u8
byte)
*/
static int sht15_wait_for_response(struct sht15_data *data)
{
- gpio_direction_input(data->pdata->gpio_data);
+ int err;
+
+ err = gpio_direction_input(data->pdata->gpio_data);
+ if (err)
+ return err;
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
if (gpio_get_value(data->pdata->gpio_data)) {
@@ -354,7 +364,10 @@ static int sht15_soft_reset(struct sht15_data *data)
*/
static void sht15_ack(struct sht15_data *data)
{
- gpio_direction_output(data->pdata->gpio_data, 0);
+ if (gpio_direction_output(data->pdata->gpio_data, 0)) {
+ dev_err(data->dev, "failed to set data line direction to
output\n");
+ return;
+ }
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSU);
@@ -362,7 +375,8 @@ static void sht15_ack(struct sht15_data *data)
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_data, 1);
- gpio_direction_input(data->pdata->gpio_data);
+ if (gpio_direction_input(data->pdata->gpio_data))
+ dev_err(data->dev, "failed to set data line direction to
input\n");
}
/**
@@ -373,7 +387,10 @@ static void sht15_ack(struct sht15_data *data)
*/
static void sht15_end_transmission(struct sht15_data *data)
{
- gpio_direction_output(data->pdata->gpio_data, 1);
+ if (gpio_direction_output(data->pdata->gpio_data, 1)) {
+ dev_err(data->dev, "failed to set data line direction to
output\n");
+ return;
+ }
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
@@ -415,7 +432,9 @@ static int sht15_send_status(struct sht15_data *data, u8
status)
ret = sht15_send_cmd(data, SHT15_WRITE_STATUS);
if (ret)
return ret;
- gpio_direction_output(data->pdata->gpio_data, 1);
+ ret = gpio_direction_output(data->pdata->gpio_data, 1);
+ if (ret)
+ return ret;
ndelay(SHT15_TSU);
sht15_send_byte(data, status);
ret = sht15_wait_for_response(data);
@@ -511,7 +530,9 @@ static int sht15_measurement(struct sht15_data *data,
if (ret)
return ret;
- gpio_direction_input(data->pdata->gpio_data);
+ ret = gpio_direction_input(data->pdata->gpio_data);
+ if (ret)
+ return ret;
atomic_set(&data->interrupt_handled, 0);
enable_irq(gpio_to_irq(data->pdata->gpio_data));
@@ -947,7 +968,11 @@ static int sht15_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "gpio request failed\n");
goto err_release_reg;
}
- gpio_direction_output(data->pdata->gpio_sck, 0);
+ ret = gpio_direction_output(data->pdata->gpio_sck, 0);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to set clock line direction to
output\n");
+ goto err_release_reg;
+ }
ret = devm_gpio_request(&pdev->dev, data->pdata->gpio_data,
"SHT15 data");
--
1.8.1
--
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