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 >
