From: Hans de Goede Date: Sat, 31 May 2025 19:05:33 +0000 (+0200) Subject: media: hi556: Fix reset GPIO timings X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=99f2211a9d89fe34b3fa847fd7a4475171406cd0;p=thirdparty%2Flinux.git media: hi556: Fix reset GPIO timings probe() requests the reset GPIO to be set to high when getting it. Immeditately after this hi556_resume() is called and sets the GPIO low. If the GPIO was low before requesting it this will result in the GPIO only very briefly spiking high and the sensor not being properly reset. The same problem also happens on back to back runtime suspend + resume. Fix this by adding a sleep of 2 ms in hi556_resume() before setting the GPIO low (if there is a reset GPIO). The final sleep is kept unconditional, because if there is e.g. no reset GPIO but a controllable clock then the sensor also needs some time after enabling the clock. Signed-off-by: Hans de Goede Signed-off-by: Sakari Ailus Signed-off-by: Hans Verkuil --- diff --git a/drivers/media/i2c/hi556.c b/drivers/media/i2c/hi556.c index aed258211b8a8..d3cc65b67855c 100644 --- a/drivers/media/i2c/hi556.c +++ b/drivers/media/i2c/hi556.c @@ -1321,7 +1321,12 @@ static int hi556_resume(struct device *dev) return ret; } - gpiod_set_value_cansleep(hi556->reset_gpio, 0); + if (hi556->reset_gpio) { + /* Assert reset for at least 2ms on back to back off-on */ + usleep_range(2000, 2200); + gpiod_set_value_cansleep(hi556->reset_gpio, 0); + } + usleep_range(5000, 5500); return 0; }