Driver of ST7703 under Linux 5.4.3

[snehal_jadhav]

Hello all,

We are looking for the driver of the display driver chip ST7703 (The display panel being used is UE040HD-RB30-L043A). We are developing a custom board with i.mx8m mini. The BSP version is Yocto Linux 5.4.3. We are able to find the driver of ST7703 https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/panel/panel-sitronix-st7703.c but unable to port it as the driver which is available is for the latest kernel version.

Thanks.

[sd05]

Hello Community,

I have same requirement as @snehal_jadhav, I am able to port the driver for st7703 the driver is getting loaded without any error but there is no display on the panel, please find the patch attached logs.

Someone please suggest how I can debug this issue further.

Driver Probe- Yes
Interface Created -Yes
Init Sequence Completed without any error -Yes
Backlight is on - Yes
Getting any image on display-no

[davidebonfanti]

I have the same behavior with im8mm custom board and ST7703-based panel.
I have a working solution with ilitek-9881 (drivers/drm/panel/panel-ilitek-ili9881c.c), but I'm not able to have backported ST7703 driver working. Also for me the driver behavior is as expected despite of what you can see on the display.

I have another issue: I'm not able to read registers from DSI interface (neither on the ilitek panel). I always get "wait rx done time out"  or   "wait pkthdr tx done time out"...

[sd05]

have you tried giving the command user cmd enable before reading?

[sd05]

Can you share your working solution

[davidebonfanti]

HI sd05, I attach the ili9881c working solution. I did very minor changes to support my panel...
Its the same work I did without success for ST7703.

The read do not work in the probe (and I expected it since dsi it still not fully enabled) nor in the enable callback when all the writes are performed apparently succesfully.

Of course I would neet it to work in the probe to detect which panel I have connected (reading ID registers) an load the proper module.

Thanks

[sd05]

Hello @davidebonfanti 

Thank you so much for sharing with us the working solution.

But still there is one challenge for us, as per our requirement we have to display the battery level on the lcd screen at uboot level, I have tried few ways do so but none of them are working.

If you are able to display the splash screen at uboot level or have any idea to do so please share.

Thanks in advance!

[davidebonfanti]

Hi, I don't have the need to use panel in uboot.
Everything I can tell is that using uboot imx_v2020.04_5.4.24_2.1.0, I had to turn on some clocks to enable dsi bus and being able to communicate with the panel.
I can see that in drivers/video/ there is the support for raydium panel used by the demoboard.
If you see what they have done with this panel and merge with the kernel-sitronix you should get the goal.
I can only share the patch to enable the clocks... (maybe on later uboots these were already running, but I'm not sure).
Hope this can help a bit

[sd05]

Thanks for your quick reply if you can share the patch that will be a great help we are working in the same direction but somehow not able to reach the goal..

uboot version-

U-Boot 2019.04

Thanks!

[davidebonfanti]

Hope this can help... even if it applies on a different version!

[davidebonfanti]

I eventually had the sitronix st7703 driver working: the issue was with MIPI_DSI_MODE_LPM flag missing.

I attach the driver working form me in kernel 5.4.70.
For what concerns the driver identification, I ended up reading it in uboot and patching the devicetree accordingly.
Regards,
Davide

[antho]

Hi David,

Can you please share your patched device tree for the st7703 ?
I assume I need to edit the &mipi_dsi node, but I'm struggling with this. I still got the error :

Oct 08 11:39:38 kernel: imx_sec_dsim_drv 32e10000.mipi_dsi: failed to get blk_ctl
Oct 08 11:39:38 kernel: imx_sec_dsim_drv 32e10000.mipi_dsi: version number is 0x1060200
Oct 08 11:39:38 kernel: imx_sec_dsim_drv 32e10000.mipi_dsi: Failed to attach bridge: 32e10000.mipi_dsi
Oct 08 11:39:38 kernel: imx_sec_dsim_drv 32e10000.mipi_dsi: failed to bind sec dsim bridge: -19

In your driver, why does the "compatible" driver array not describe the st7703 device ?

{ .compatible = "rocktech,jh057n00900", .data = &jh057n00900_panel_desc },
{ .compatible = "xingbangda,xbd599", .data = &xbd599_desc },
{ .compatible = "techshine,ts-p0500063b", .data = &p0500063b_desc },

Thanks

[jiangyaqiang]

Hi davidebonfanti:

    I know it's a long time ago of your topic, but the issue has blocked me about two weeks.

    I'm tring the driver a ST7703 panel by IMX8MM, kernel 5.4.70. But fail to get it wok.

    I have downloaded your driver , just modify the mode and lane and init parameter according to vendor.

    And I found that it seems sometimes the init command is not send success, because sometimes the VCOM voltage of the panel is not correct(it should changed accord to init command of VCOM), and sometimes is correct.

    Any suggection ?

    Best Regards.

[sd05]

Thank you

[Bio_TICFSL]

Hello Snehal,

Sorry but in this case you must port the driver to the current kernel you might have. The linux BSP doesn´t have this driver.

We apologize for the inconvenience