On Fri, Jun 09, 2023 at 04:59:50PM +0200, Miquel Raynal wrote: > This panel from Emerging Display Technologies Corporation features an > ST7789V2 panel inside which is almost identical to what the Sitronix > panel driver supports. > > In practice, the module physical size is specific, and experiments show > that the display will malfunction if any of the following situation > occurs: > * Pixel clock is above 3MHz > * Pixel clock is not inverted > I could not properly identify the reasons behind these failures, scope > captures show valid input signals. The patch includes an additional change where the bus_flags are assigned to the connector. At least tell why, or maybe split it out. Other panels could learn to do the same - and I assume you did it because it was required in the atmel_hlcd driver. Sam > > Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> > --- > .../gpu/drm/panel/panel-sitronix-st7789v.c | 34 +++++++++++++++++-- > 1 file changed, 32 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c > index 212bccc31804..7de192a3a8aa 100644 > --- a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c > +++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c > @@ -30,7 +30,8 @@ > #define ST7789V_RGBCTRL_RCM(n) (((n) & 3) << 5) > #define ST7789V_RGBCTRL_VSYNC_HIGH BIT(3) > #define ST7789V_RGBCTRL_HSYNC_HIGH BIT(2) > -#define ST7789V_RGBCTRL_PCLK_HIGH BIT(1) > +#define ST7789V_RGBCTRL_PCLK_FALLING BIT(1) > +#define ST7789V_RGBCTRL_PCLK_RISING 0 > #define ST7789V_RGBCTRL_VBP(n) ((n) & 0x7f) > #define ST7789V_RGBCTRL_HBP(n) ((n) & 0x1f) > > @@ -117,6 +118,7 @@ struct st7789v_panel_info { > u16 width_mm; > u16 height_mm; > u32 bus_format; > + u32 bus_flags; > }; > > struct st7789v { > @@ -175,6 +177,18 @@ static const struct drm_display_mode default_mode = { > .vtotal = 320 + 8 + 4 + 4, > }; > > +static const struct drm_display_mode slow_mode = { > + .clock = 3000, > + .hdisplay = 240, > + .hsync_start = 240 + 38, > + .hsync_end = 240 + 38 + 10, > + .htotal = 240 + 38 + 10 + 10, > + .vdisplay = 320, > + .vsync_start = 320 + 8, > + .vsync_end = 320 + 8 + 4, > + .vtotal = 320 + 8 + 4 + 4, > +}; > + > static int st7789v_get_modes(struct drm_panel *panel, > struct drm_connector *connector) > { > @@ -197,6 +211,7 @@ static int st7789v_get_modes(struct drm_panel *panel, > > connector->display_info.width_mm = panel_info->width_mm; > connector->display_info.height_mm = panel_info->height_mm; > + connector->display_info.bus_flags = panel_info->bus_flags; > drm_display_info_set_bus_formats(&connector->display_info, > &panel_info->bus_format, 1); > > @@ -206,8 +221,13 @@ static int st7789v_get_modes(struct drm_panel *panel, > static int st7789v_prepare(struct drm_panel *panel) > { > struct st7789v *ctx = panel_to_st7789v(panel); > + const struct st7789v_panel_info *panel_info = ctx->panel_info; > + u8 pck = ST7789V_RGBCTRL_PCLK_FALLING; > int ret; > > + if (panel_info->bus_flags & DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE) > + pck = ST7789V_RGBCTRL_PCLK_RISING; > + > ret = regulator_enable(ctx->power); > if (ret) > return ret; > @@ -321,7 +341,7 @@ static int st7789v_prepare(struct drm_panel *panel) > ST7789V_RGBCTRL_RCM(2) | > ST7789V_RGBCTRL_VSYNC_HIGH | > ST7789V_RGBCTRL_HSYNC_HIGH | > - ST7789V_RGBCTRL_PCLK_HIGH)); > + pck)); > ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_RGBCTRL_VBP(8))); > ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_RGBCTRL_HBP(20))); > > @@ -422,14 +442,24 @@ static const struct st7789v_panel_info st7789v_info = { > .bus_format = MEDIA_BUS_FMT_RGB666_1X18, > }; > > +static const struct st7789v_panel_info et028013dma_info = { > + .display_mode = &slow_mode, > + .width_mm = 43, > + .height_mm = 58, > + .bus_format = MEDIA_BUS_FMT_RGB666_1X18, > + .bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE, > +}; > + > static const struct of_device_id st7789v_of_match[] = { > { .compatible = "sitronix,st7789v", .data = &st7789v_info }, > + { .compatible = "edt,et028013dma", .data = &et028013dma_info }, > { } > }; > MODULE_DEVICE_TABLE(of, st7789v_of_match); > > static const struct spi_device_id st7789v_ids[] = { > { "st7789v", }, > + { "et028013dma", }, > { /* sentinel */ } > }; > MODULE_DEVICE_TABLE(spi, st7789v_ids); > -- > 2.34.1