The shift6mq's variant supports controlling the backlight via DSI
commands. Use that if a max_brightness is set in the device specific
data.
Signed-off-by: Guido Günther <agx@sigxcpu.org>
---
drivers/gpu/drm/panel/panel-visionox-rm69299.c | 67 ++++++++++++++++++++++++++
1 file changed, 67 insertions(+)
diff --git a/drivers/gpu/drm/panel/panel-visionox-rm69299.c b/drivers/gpu/drm/panel/panel-visionox-rm69299.c
index 2216d38366ea37368d15480f9d8a8ccbfe77ba3b..5e5ff6056c80e67a5bf8fe4911cdbc588db5d03b 100644
--- a/drivers/gpu/drm/panel/panel-visionox-rm69299.c
+++ b/drivers/gpu/drm/panel/panel-visionox-rm69299.c
@@ -3,6 +3,7 @@
* Copyright (c) 2019, The Linux Foundation. All rights reserved.
*/
+#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/property.h>
@@ -20,6 +21,8 @@ struct visionox_rm69299_panel_desc {
const struct drm_display_mode *mode;
const u8 *init_seq;
unsigned int init_seq_len;
+ int max_brightness;
+ int initial_brightness;
};
struct visionox_rm69299 {
@@ -285,6 +288,63 @@ static const struct drm_panel_funcs visionox_rm69299_drm_funcs = {
.get_modes = visionox_rm69299_get_modes,
};
+static int visionox_rm69299_bl_get_brightness(struct backlight_device *bl)
+{
+ struct mipi_dsi_device *dsi = bl_get_data(bl);
+ u16 brightness;
+ int ret;
+
+ dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+ ret = mipi_dsi_dcs_get_display_brightness(dsi, &brightness);
+ if (ret < 0)
+ return ret;
+
+ dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+ return brightness;
+}
+
+static int visionox_rm69299_bl_update_status(struct backlight_device *bl)
+{
+ struct mipi_dsi_device *dsi = bl_get_data(bl);
+ u16 brightness = backlight_get_brightness(bl);
+ int ret;
+
+ dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+ ret = mipi_dsi_dcs_set_display_brightness(dsi, brightness);
+ if (ret < 0)
+ return ret;
+
+ dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+ return 0;
+}
+
+static const struct backlight_ops visionox_rm69299_bl_ops = {
+ .update_status = visionox_rm69299_bl_update_status,
+ .get_brightness = visionox_rm69299_bl_get_brightness,
+};
+
+static struct backlight_device *
+visionox_rm69299_create_backlight(struct visionox_rm69299 *ctx)
+{
+ struct device *dev = &ctx->dsi->dev;
+ const struct backlight_properties props = {
+ .type = BACKLIGHT_RAW,
+ .brightness = ctx->desc->initial_brightness,
+ .max_brightness = ctx->desc->max_brightness,
+ };
+
+ if (!ctx->desc->max_brightness)
+ return 0;
+
+ return devm_backlight_device_register(dev, dev_name(dev), dev, ctx->dsi,
+ &visionox_rm69299_bl_ops,
+ &props);
+}
+
static int visionox_rm69299_probe(struct mipi_dsi_device *dsi)
{
struct device *dev = &dsi->dev;
@@ -316,6 +376,11 @@ static int visionox_rm69299_probe(struct mipi_dsi_device *dsi)
return PTR_ERR(ctx->reset_gpio);
}
+ ctx->panel.backlight = visionox_rm69299_create_backlight(ctx);
+ if (IS_ERR(ctx->panel.backlight))
+ return dev_err_probe(dev, PTR_ERR(ctx->panel.backlight),
+ "Failed to create backlight\n");
+
drm_panel_add(&ctx->panel);
dsi->lanes = 4;
@@ -353,6 +418,8 @@ const struct visionox_rm69299_panel_desc visionox_rm69299_shift_desc = {
.mode = &visionox_rm69299_1080x2160_60hz,
.init_seq = (const u8 *)visionox_rm69299_1080x2160_60hz_init_seq,
.init_seq_len = ARRAY_SIZE(visionox_rm69299_1080x2160_60hz_init_seq),
+ .max_brightness = 255,
+ .initial_brightness = 50,
};
static const struct of_device_id visionox_rm69299_of_match[] = {
--
2.51.0
Hi Guido,
kernel test robot noticed the following build warnings:
[auto build test WARNING on b320789d6883cc00ac78ce83bccbfe7ed58afcf0]
url: https://github.com/intel-lab-lkp/linux/commits/Guido-G-nther/drm-panel-visionox-rm69299-Fix-clock-frequency-for-SHIFT6mq/20250901-222400
base: b320789d6883cc00ac78ce83bccbfe7ed58afcf0
patch link: https://lore.kernel.org/r/20250901-shift6mq-panel-v1-3-444b4abbfaea%40sigxcpu.org
patch subject: [PATCH 3/3] drm/panel: visionox-rm69299: Add backlight support
config: x86_64-randconfig-123-20250902 (https://download.01.org/0day-ci/archive/20250902/202509021907.mZZ38HtR-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14+deb12u1) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250902/202509021907.mZZ38HtR-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509021907.mZZ38HtR-lkp@intel.com/
sparse warnings: (new ones prefixed by >>)
>> drivers/gpu/drm/panel/panel-visionox-rm69299.c:341:24: sparse: sparse: Using plain integer as NULL pointer
drivers/gpu/drm/panel/panel-visionox-rm69299.c:411:42: sparse: sparse: symbol 'visionox_rm69299_1080p_display_desc' was not declared. Should it be static?
drivers/gpu/drm/panel/panel-visionox-rm69299.c:417:42: sparse: sparse: symbol 'visionox_rm69299_shift_desc' was not declared. Should it be static?
vim +341 drivers/gpu/drm/panel/panel-visionox-rm69299.c
329
330 static struct backlight_device *
331 visionox_rm69299_create_backlight(struct visionox_rm69299 *ctx)
332 {
333 struct device *dev = &ctx->dsi->dev;
334 const struct backlight_properties props = {
335 .type = BACKLIGHT_RAW,
336 .brightness = ctx->desc->initial_brightness,
337 .max_brightness = ctx->desc->max_brightness,
338 };
339
340 if (!ctx->desc->max_brightness)
> 341 return 0;
342
343 return devm_backlight_device_register(dev, dev_name(dev), dev, ctx->dsi,
344 &visionox_rm69299_bl_ops,
345 &props);
346 }
347
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On 01/09/2025 16:22, Guido Günther wrote:
> The shift6mq's variant supports controlling the backlight via DSI
> commands. Use that if a max_brightness is set in the device specific
> data.
>
> Signed-off-by: Guido Günther <agx@sigxcpu.org>
> ---
> drivers/gpu/drm/panel/panel-visionox-rm69299.c | 67 ++++++++++++++++++++++++++
> 1 file changed, 67 insertions(+)
>
> diff --git a/drivers/gpu/drm/panel/panel-visionox-rm69299.c b/drivers/gpu/drm/panel/panel-visionox-rm69299.c
> index 2216d38366ea37368d15480f9d8a8ccbfe77ba3b..5e5ff6056c80e67a5bf8fe4911cdbc588db5d03b 100644
> --- a/drivers/gpu/drm/panel/panel-visionox-rm69299.c
> +++ b/drivers/gpu/drm/panel/panel-visionox-rm69299.c
> @@ -3,6 +3,7 @@
> * Copyright (c) 2019, The Linux Foundation. All rights reserved.
> */
>
> +#include <linux/backlight.h>
> #include <linux/delay.h>
> #include <linux/module.h>
> #include <linux/property.h>
> @@ -20,6 +21,8 @@ struct visionox_rm69299_panel_desc {
> const struct drm_display_mode *mode;
> const u8 *init_seq;
> unsigned int init_seq_len;
> + int max_brightness;
> + int initial_brightness;
> };
>
> struct visionox_rm69299 {
> @@ -285,6 +288,63 @@ static const struct drm_panel_funcs visionox_rm69299_drm_funcs = {
> .get_modes = visionox_rm69299_get_modes,
> };
>
> +static int visionox_rm69299_bl_get_brightness(struct backlight_device *bl)
> +{
> + struct mipi_dsi_device *dsi = bl_get_data(bl);
> + u16 brightness;
> + int ret;
> +
> + dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
> +
> + ret = mipi_dsi_dcs_get_display_brightness(dsi, &brightness);
> + if (ret < 0)
> + return ret;
> +
> + dsi->mode_flags |= MIPI_DSI_MODE_LPM;
> +
> + return brightness;
> +}
> +
> +static int visionox_rm69299_bl_update_status(struct backlight_device *bl)
> +{
> + struct mipi_dsi_device *dsi = bl_get_data(bl);
> + u16 brightness = backlight_get_brightness(bl);
> + int ret;
> +
> + dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
> +
> + ret = mipi_dsi_dcs_set_display_brightness(dsi, brightness);
> + if (ret < 0)
> + return ret;
> +
> + dsi->mode_flags |= MIPI_DSI_MODE_LPM;
> +
> + return 0;
> +}
> +
> +static const struct backlight_ops visionox_rm69299_bl_ops = {
> + .update_status = visionox_rm69299_bl_update_status,
> + .get_brightness = visionox_rm69299_bl_get_brightness,
> +};
> +
> +static struct backlight_device *
> +visionox_rm69299_create_backlight(struct visionox_rm69299 *ctx)
> +{
> + struct device *dev = &ctx->dsi->dev;
> + const struct backlight_properties props = {
> + .type = BACKLIGHT_RAW,
> + .brightness = ctx->desc->initial_brightness,
> + .max_brightness = ctx->desc->max_brightness,
> + };
> +
> + if (!ctx->desc->max_brightness)
> + return 0;
> +
> + return devm_backlight_device_register(dev, dev_name(dev), dev, ctx->dsi,
> + &visionox_rm69299_bl_ops,
> + &props);
> +}
> +
> static int visionox_rm69299_probe(struct mipi_dsi_device *dsi)
> {
> struct device *dev = &dsi->dev;
> @@ -316,6 +376,11 @@ static int visionox_rm69299_probe(struct mipi_dsi_device *dsi)
> return PTR_ERR(ctx->reset_gpio);
> }
>
> + ctx->panel.backlight = visionox_rm69299_create_backlight(ctx);
> + if (IS_ERR(ctx->panel.backlight))
> + return dev_err_probe(dev, PTR_ERR(ctx->panel.backlight),
> + "Failed to create backlight\n");
> +
> drm_panel_add(&ctx->panel);
>
> dsi->lanes = 4;
> @@ -353,6 +418,8 @@ const struct visionox_rm69299_panel_desc visionox_rm69299_shift_desc = {
> .mode = &visionox_rm69299_1080x2160_60hz,
> .init_seq = (const u8 *)visionox_rm69299_1080x2160_60hz_init_seq,
> .init_seq_len = ARRAY_SIZE(visionox_rm69299_1080x2160_60hz_init_seq),
> + .max_brightness = 255,
> + .initial_brightness = 50,
> };
>
> static const struct of_device_id visionox_rm69299_of_match[] = {
>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
© 2016 - 2025 Red Hat, Inc.