This is a note to let you know that I've just added the patch titled auxdisplay: ht16k33: Connect backlight to fbdev to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: auxdisplay-ht16k33-connect-backlight-to-fbdev.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 9ec6494c78b4f9e1544624c8e536fe8a906ff2b4 Author: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Date: Tue Oct 19 16:45:08 2021 +0200 auxdisplay: ht16k33: Connect backlight to fbdev [ Upstream commit 80f9eb70fd9276938f0a131f76d438021bfd8b34 ] Currently /sys/class/graphics/fb0/bl_curve is not accessible (-ENODEV), as the driver does not connect the backlight to the frame buffer device. Fix this moving backlight initialization up, and filling in fb_info.bl_dev. Fixes: 8992da44c6805d53 ("auxdisplay: ht16k33: Driver for LED controller") Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Reviewed-by: Robin van der Gracht <robin@xxxxxxxxxxx> Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c index 194370ae37dd0..f6927871fa4e8 100644 --- a/drivers/auxdisplay/ht16k33.c +++ b/drivers/auxdisplay/ht16k33.c @@ -418,6 +418,33 @@ static int ht16k33_probe(struct i2c_client *client, if (err) return err; + /* Backlight */ + memset(&bl_props, 0, sizeof(struct backlight_properties)); + bl_props.type = BACKLIGHT_RAW; + bl_props.max_brightness = MAX_BRIGHTNESS; + + bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl", + &client->dev, priv, + &ht16k33_bl_ops, &bl_props); + if (IS_ERR(bl)) { + dev_err(&client->dev, "failed to register backlight\n"); + return PTR_ERR(bl); + } + + err = of_property_read_u32(node, "default-brightness-level", + &dft_brightness); + if (err) { + dft_brightness = MAX_BRIGHTNESS; + } else if (dft_brightness > MAX_BRIGHTNESS) { + dev_warn(&client->dev, + "invalid default brightness level: %u, using %u\n", + dft_brightness, MAX_BRIGHTNESS); + dft_brightness = MAX_BRIGHTNESS; + } + + bl->props.brightness = dft_brightness; + ht16k33_bl_update_status(bl); + /* Framebuffer (2 bytes per column) */ BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE); fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL); @@ -450,6 +477,7 @@ static int ht16k33_probe(struct i2c_client *client, fbdev->info->screen_size = HT16K33_FB_SIZE; fbdev->info->fix = ht16k33_fb_fix; fbdev->info->var = ht16k33_fb_var; + fbdev->info->bl_dev = bl; fbdev->info->pseudo_palette = NULL; fbdev->info->flags = FBINFO_FLAG_DEFAULT; fbdev->info->par = priv; @@ -462,34 +490,6 @@ static int ht16k33_probe(struct i2c_client *client, if (err) goto err_fbdev_unregister; - /* Backlight */ - memset(&bl_props, 0, sizeof(struct backlight_properties)); - bl_props.type = BACKLIGHT_RAW; - bl_props.max_brightness = MAX_BRIGHTNESS; - - bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl", - &client->dev, priv, - &ht16k33_bl_ops, &bl_props); - if (IS_ERR(bl)) { - dev_err(&client->dev, "failed to register backlight\n"); - err = PTR_ERR(bl); - goto err_fbdev_unregister; - } - - err = of_property_read_u32(node, "default-brightness-level", - &dft_brightness); - if (err) { - dft_brightness = MAX_BRIGHTNESS; - } else if (dft_brightness > MAX_BRIGHTNESS) { - dev_warn(&client->dev, - "invalid default brightness level: %u, using %u\n", - dft_brightness, MAX_BRIGHTNESS); - dft_brightness = MAX_BRIGHTNESS; - } - - bl->props.brightness = dft_brightness; - ht16k33_bl_update_status(bl); - ht16k33_fb_queue(priv); return 0;