On Tue, May 26, 2026 at 04:02:45PM +0530, Arpit Saini wrote: > Hi Krzysztof , Dmitry > > On 5/20/2026 6:56 PM, Dmitry Baryshkov wrote: > > On Wed, May 20, 2026 at 06:10:57PM +0530, Arpit Saini wrote: > > > Hi Krzysztof , Dmitry > > > > > > On 5/19/2026 4:02 PM, Krzysztof Kozlowski wrote: > > > > On Mon, May 18, 2026 at 04:34:12PM +0530, Arpit Saini wrote: > > > > > ILI7807S is a DSI display controller used to drive MIPI-DSI panels. > > > > > The DLC DLC0697 1080x1920 LCD panel is based on this controller. > > > > I can't find this panel on the DLC website. Do you have a pointer to the > > product page? > > > https://v4.cecdn.yun300.cn/100001_2012175013/DLC0697AAL21MF-1.pdf
"Invalid referrer" > > > > > > > > > > The panel requires a reset GPIO, backlight enable GPIO, I/O voltage > > > > > > > > If panel requires it, so should the binding. > > > > > > > Ack, I will update. > > > > ... > > > > > > > > > + reg: > > > > > + maxItems: 1 > > > > > + description: DSI virtual channel > > > > > + > > > > > + reset-gpios: true > > > > > + > > > > > + backlight-en-gpios: > > > > > + description: Backlight enable GPIO (active high) > > > > > > > > What is the name of the pin in ili7807s device? > > > > > > > Display daughter card has WLED driver as well as LCD bias driver. > > > > What is the display daughter card here? Is it a Qualcomm board or is it > > a part of the panel? > > > > Also you wrote a lot of text, but you didn't really answer either of the > > quesitons. Is there a GPIO on the panel connector that enables the > > backlight? If not, this is some external supply on your (assumingly) > > daughter card. And it should be modelled accordingly. Still unanswered. > > > > > > > > The WLED driver's Enable is coming from WLED_P1_EN and PWM is coming from > > > LCD_CABC output of the panel. > > > > > > DISPLAY0_BACKLIGHT_ENABLE (GPIO 91) of ITP baseband card ==> WLED_P1_EN of > > > Display Daughter Card (DC) > > > > > > In the display daughter card of Shikra ITP platform, we are not using the > > > external PWM for WLED driver. But connected the CABC output of the panel > > > to > > > the WLED driver. Backlight update is happening using MIPI DCS command > > > which > > > is driving the CABC output (i.e., PWM for WLED). > > > > > > Because of above HW configuration, we need to enable the MIPI DCS > > > brightness > > > update on this panel. The below command of dlc0697_init_sequence() is > > > enabling this. > > > mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x53, 0x24); > > > > So, this should be then dependent on the presence of the backlight in > > the DT. Either it is a panel-internal one, or an external one. > > > > > > > > > > > After checking this, I realized that this panel can be used without the > > > DCS > > > backlight as well when it's using PWM based backlight control. > > > > > > I can add `has_dcs_backlight` in panel_desc and set it true for dlc0697. > > > I > > > will update bindings and add backlight as optional property. > > > > Why? Use backlight property instead. It's already there. Anyway, you > > really, really need to describe the panel in the bidings. Not your > > daughter card. > > > This `has_dcs_backlight` in panel_desc will serves both the purpose, as for > our current platform constraint , we need to create our own backlight. > But this panel can be used without the DCS > backlight as well when it's using PWM based backlight control. > > So in this case I need to implement the backlight as implemented in > panel-novatek-nt36523.c, panel-himax-hx83121a.c. > > with this implementation ,I will remove the backlight from the dt-bindings. Much easier. Call drm_panel_of_backlight() and if there is no error and panel->backlight is still NULL, then create your own backlight device. > > Please let me know,if I am missing something. > > Thanks, > Arpit > > -- With best wishes Dmitry
