Re: [PATCH v3] drm/panel: st7703: Fix Panel Initialization for Anbernic RG353V-V2

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Hi,
On Sat, Feb 10, 2024 at 01:24:43AM +0100, Ao Zhong wrote:
> This patch addresses an issue with the Anbernic RG353V-V2 panel
> initialization that was caused by incorrect parameter. The correct
> initialization sequence was derived by referencing the JELOS (Just
> Enough Linux OS) BSP kernel's device tree for the V2 panel, which is
> identified by the ID "38 21". The relevant device tree can be found at:
> 
> https://github.com/JustEnoughLinuxOS/rk356x-kernel/blob/d4d7335a5ca18fc216a29712d5c6cecfb86147d2/arch/arm64/boot/dts/rockchip/rk3568-evb-rg353v.dtsi#L582
> 
> The proper initialization sequence was further informed by dissecting
> instructions as outlined in the "Rockchip_DRM_Panel_Porting_Guide",
> specifically in Chapter 3.3 of the document.
> 
> https://web.archive.org/web/20240209211932if_/http://download.t-firefly.com/product/Board/Common/Document/Developer/Rockchip_Developer_Guide_DRM_Panel_Porting_CN.pdf
> 
> Upon comparing the initialization sequence within the
> rg353v2_init_sequence function against the device tree in the BSP
> kernel, discrepancies were identified in two instructions. The relevant
> instructions in the device tree are:
> 
> 1. 15 00 03 b6 7f 7f corresponding to the ST7703_CMD_SETVCOM command
>    with parameters 7f 7f
> 2. 39 00 05 b8 26 62 f0 63 corresponding to the ST7703_CMD_SETPOWER_EXT
>    command with parameters 26 62 f0 63
> 
> Adjusting the parameters to match those specified in the BSP kernel's
> device tree allow the panel to initialize correctly.
> 
> Signed-off-by: Ao Zhong <hacc1225@xxxxxxxxx>
> ---
>  drivers/gpu/drm/panel/panel-sitronix-st7703.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7703.c b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
> index b55bafd1a8be..a346d6c3d283 100644
> --- a/drivers/gpu/drm/panel/panel-sitronix-st7703.c
> +++ b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
> @@ -357,8 +357,8 @@ static int rg353v2_init_sequence(struct st7703 *ctx)
>  			       0x28, 0x03, 0xff, 0x00, 0x00, 0x00, 0x00);
>  	mipi_dsi_dcs_write_seq(dsi, ST7703_CMD_SETCYC, 0x80);
>  	mipi_dsi_dcs_write_seq(dsi, ST7703_CMD_SETBGP, 0x0a, 0x0a);
> -	mipi_dsi_dcs_write_seq(dsi, ST7703_CMD_SETVCOM, 0x92, 0x92);
> -	mipi_dsi_dcs_write_seq(dsi, ST7703_CMD_SETPOWER_EXT, 0x25, 0x22,
> +	mipi_dsi_dcs_write_seq(dsi, ST7703_CMD_SETVCOM, 0x7f, 0x7f);
> +	mipi_dsi_dcs_write_seq(dsi, ST7703_CMD_SETPOWER_EXT, 0x26, 0x62,
>  			       0xf0, 0x63);
>  	mipi_dsi_dcs_write_seq(dsi, ST7703_CMD_SETMIPI, 0x33, 0x81, 0x05,
>  			       0xf9, 0x0e, 0x0e, 0x20, 0x00, 0x00, 0x00,
> 0x00,

Reviewed-by: Guido Günther <agx@xxxxxxxxxxx>
 -- Guido

> -- 
> 2.43.0
> 



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