auxdisplay: ht16k33: Connect backlight to fbdev

BugLink: https://bugs.launchpad.net/bugs/1951822
[ 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@linux-m68k.org>
Reviewed-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c
index 1e69cc6d21a0dca208267f58476a1dde739203fd..2b630e194570f6e570ae2fe8d5ae8b2b57b04c65 100644 (file)
--- a/drivers/auxdisplay/ht16k33.c
+++ b/drivers/auxdisplay/ht16k33.c
@@ -413,6 +413,33 @@ 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);
@@ -445,6 +472,7 @@ 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;
@@ -460,34 +488,6 @@ static int ht16k33_probe(struct i2c_client *client,
                        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;