Currently, the V4L2 subdevice is also created when the device is not
available/connected. In this case, dmesg shows the following:
[ 10.419510] imx290 7-001a: Error writing reg 0x301c: -6
[ 10.428981] imx290 7-001a: Error writing reg 0x3020: -6
[ 10.442712] imx290 7-001a: Error writing reg 0x3018: -6
[ 10.454018] imx290 7-001a: Error writing reg 0x3020: -6
which seems to come from imx290_ctrl_update() after the subdev init is
finished. However, as the errors are ignored, the subdev is initialized
but simply does not work. From userspace perspective, there is no
visible difference between a working and not-working subdevice (except
when trying it out or watching for the error message).
This commit adds a simple availability check before starting with the
subdev initialization to error out instead.
Signed-off-by: Benjamin Bara <benjamin.bara@xxxxxxxxxxx>
---
Changes since v1:
- define operating/standby mode and use it
- read out the standby mode during probe and ensure it is standby
---
drivers/media/i2c/imx290.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
index 4150e6e4b9a6..2a869576600c 100644
--- a/drivers/media/i2c/imx290.c
+++ b/drivers/media/i2c/imx290.c
@@ -29,6 +29,8 @@
#include <media/v4l2-subdev.h>
#define IMX290_STANDBY CCI_REG8(0x3000)
+#define IMX290_STANDBY_OPERATING (0 << 0)
+#define IMX290_STANDBY_STANDBY (1 << 0)
#define IMX290_REGHOLD CCI_REG8(0x3001)
#define IMX290_XMSTA CCI_REG8(0x3002)
#define IMX290_ADBIT CCI_REG8(0x3005)
@@ -1016,7 +1018,7 @@ static int imx290_start_streaming(struct imx290 *imx290,
return ret;
}
- cci_write(imx290->regmap, IMX290_STANDBY, 0x00, &ret);
+ cci_write(imx290->regmap, IMX290_STANDBY, IMX290_STANDBY_OPERATING, &ret);
msleep(30);
@@ -1029,7 +1031,7 @@ static int imx290_stop_streaming(struct imx290 *imx290)
{
int ret = 0;
- cci_write(imx290->regmap, IMX290_STANDBY, 0x01, &ret);
+ cci_write(imx290->regmap, IMX290_STANDBY, IMX290_STANDBY_STANDBY, &ret);
msleep(30);
@@ -1520,6 +1522,7 @@ static int imx290_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct imx290 *imx290;
+ u64 val;
int ret;
imx290 = devm_kzalloc(dev, sizeof(*imx290), GFP_KERNEL);
@@ -1580,6 +1583,16 @@ static int imx290_probe(struct i2c_client *client)
pm_runtime_set_autosuspend_delay(dev, 1000);
pm_runtime_use_autosuspend(dev);
+ /* Make sure the sensor is available before V4L2 subdev init. */
+ ret = cci_read(imx290->regmap, IMX290_STANDBY, &val, NULL);
+ if (ret)
+ goto err_pm;
+ if (val != IMX290_STANDBY_STANDBY) {
+ dev_err(dev, "Sensor is not in standby mode\n");
+ ret = -ENODEV;
+ goto err_pm;
+ }
+
/* Initialize the V4L2 subdev. */
ret = imx290_subdev_init(imx290);
if (ret)
--
2.46.0
