On Thu, May 02, 2019 at 02:01:45PM +0200, Lucas Stach wrote:
Hi Daniel,
Am Donnerstag, den 02.05.2019, 11:33 +0100 schrieb Daniel Thompson:
On 29/04/2019 16:29, Lucas Stach wrote:
This way the backlight can be referenced through its device node and enabling/disabling can be managed through the panel driver.
Is it possible to implement something similar to pwm_backlight_initial_power_state() to handle this?
I'm not aware of any protocol to the RAVE-SP that would allow to read back the backlight state. AFAICS the backlight is implemented as a unidirectional protocol.
That function does two things... one is read the current power state to ensure meta-data is correctly up to date which cannot be replicated. The other is to choose different behaviour depending on whether the backlight is standalone or has a phandle link to another device.
Does the second part apply to the rave-sp?
Daniel.
backlight drivers already suffer from too much diversity so I prefer things like this to align behaviour with the (fairly heavilyly used) PWM driver if possible.
Daniel.
Signed-off-by: Lucas Stach l.stach@pengutronix.de
drivers/video/backlight/rave-sp-backlight.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/video/backlight/rave-sp-backlight.c b/drivers/video/backlight/rave-sp-backlight.c index 462f14a1b19d..d296bfcf4396 100644 --- a/drivers/video/backlight/rave-sp-backlight.c +++ b/drivers/video/backlight/rave-sp-backlight.c @@ -48,15 +48,13 @@ static int rave_sp_backlight_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev; struct backlight_device *bd;
- bd = devm_backlight_device_register(dev, pdev->name, dev->parent,
- bd = devm_backlight_device_register(dev, pdev->name, dev,
dev_get_drvdata(dev->parent), &rave_sp_backlight_ops, &rave_sp_backlight_props); if (IS_ERR(bd)) return PTR_ERR(bd);
- backlight_update_status(bd);
return 0;
}