media: atomisp: Turn on sensor power from atomisp_set_fmt()

ATM the atomisp driver does not call s_power() at all when no s_input
ioctl() is done by the application. This breaks older sensor drivers
which rely on s_power() for power-management.

Some drivers have worked around this, e.g. commit c5fafbad ("media:
atomisp: gc0310: Power on sensor from set_fmt() callback") and
commit b3118a94 ("media: atomisp: ov2722: Power on sensor from
set_fmt() callback"), but this really should be fixed in the atomisp
driver itself, so that all old drivers can work.

A logical place to call s_power() would be from atomisp_start_streaming() /
atomisp_stop_streaming(). But some older drivers, e.g. the atomisp-ov2722
driver already write mode related registers on set_fmt() instead of waiting
on stream on. So the s_power(1) needs to happen at the first set_fmt().

Add an atomisp_s_sensor_power(..., 1) call just before calling set_fmt()
for this. If the power was already enabled through e.g. a s_input ioctl
atomisp_s_sensor_power() will skip calling the s_power() v4l2-subdev-op
a second time.
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/staging/media/atomisp/pci/atomisp_cmd.c

@@ -3760,6 +3760,17 @@ static int atomisp_set_sensor_crop_and_fmt(struct atomisp_device *isp,
 	if (!input->camera)
 		return -EINVAL;
 
+	/*
+	 * Some old sensor drivers already write the registers on set_fmt
+	 * instead of on stream on, power on the sensor now (on newer
+	 * sensor drivers the s_power op is a no-op).
+	 */
+	if (which == V4L2_SUBDEV_FORMAT_ACTIVE) {
+		ret = atomisp_s_sensor_power(isp, isp->asd.input_curr, 1);
+		if (ret)
+			return ret;
+	}
+
 	sd_state = (which == V4L2_SUBDEV_FORMAT_TRY) ? input->try_sd_state :
 						       input->camera->active_state;
 	if (sd_state)