On Mon, Dec 5, 2016 at 10:24 AM, Umair Khan <[email protected]> wrote:
> On Mon, Dec 5, 2016 at 12:56 PM, Ran Shalit <[email protected]> wrote: > > Hello, > > > > I am trying to turn off screen using sysfs entries, > > but I'm having some difficulties with it: > > > > 1. > > command: > > echo 0 > /sys/devices/platform/s5p-dsim.0/ea8061/backlight/panel/ > brightness > > result: > > screen is dimmed - BUT not turned off > > > > 2. > > command: > > cat > > /sys/devices/platform/s5p-dsim.0/ea8061/backlight/panel/ > actual_brightness > > 20 > > > > This strengthen the fast that we didn't turned off brightness completely > > > > 3. In this point I though that maybe I can turn off the whole brightness > > device > > > > ls /sys/devices/platform/s5p-dsim.0/ea8061/backlight/panel/ > > actual_brightness > > auto_brightness > > bl_power > > brightness > > device > > dimming > > max_brightness > > power > > subsystem > > type > > uevent > > > > I made some trials , but didn't made it turned off yet. > > Is there any idea if it's possible to turn it off completely ? > > In my opinion, you'll need to have a look into the driver's code. > See if that exposes a mechanism to turn off the screen at all. > > Right, Seems that sysfs exports features that drivers might not support (or supported differently between different drivers) for ea8061 driver: Yet, not sure why on setting brightness 0 , I get that that it that "catual_brightness" is 20. See ea8061_set_brightness below. https://github.com/gokhanmoral/siyahkernel-sgs3/blob/master-3.0.31/drivers/video/backlight/ea8061.c static int ea8061_set_brightness(struct backlight_device *bd) { int ret = 0, brightness = bd->props.brightness; struct ea8061 *lcd = bl_get_data(bd); if (lcd->power == FB_BLANK_POWERDOWN) { dev_err(lcd->dev, "lcd off: brightness set failed.\n"); return -EINVAL; } if (brightness < MIN_BRIGHTNESS || brightness > bd->props.max_brightness) { dev_err(lcd->dev, "lcd brightness should be %d to %d.\n", MIN_BRIGHTNESS, MAX_BRIGHTNESS); return -EINVAL; } ret = ea8061_gamma_ctrl(lcd, brightness); if (ret) { dev_err(&bd->dev, "lcd brightness setting failed.\n"); return -EIO; } return ret; } Thanks, Ran - Umair >
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