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
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.
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.
Please let me know,if I am missing something.
Thanks,
Arpit
