Adding support for max-pixelclock and max-width device tree entries. As some devices that use the tilcdc hardware module have restrictions on the allowed/tested values. Also update DT bindings document to reflect new parameters.
Signed-off-by: Darren Etheridge detheridge@ti.com --- .../devicetree/bindings/drm/tilcdc/tilcdc.txt | 8 +++++++ drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 23 ++++++++++++++++++- drivers/gpu/drm/tilcdc/tilcdc_drv.c | 15 ++++++++++++- drivers/gpu/drm/tilcdc/tilcdc_drv.h | 22 +++++++++++++++++++ 4 files changed, 65 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/drm/tilcdc/tilcdc.txt b/Documentation/devicetree/bindings/drm/tilcdc/tilcdc.txt index e5f1301..fff10da 100644 --- a/Documentation/devicetree/bindings/drm/tilcdc/tilcdc.txt +++ b/Documentation/devicetree/bindings/drm/tilcdc/tilcdc.txt @@ -10,6 +10,14 @@ Recommended properties: services interrupts for this device. - ti,hwmods: Name of the hwmod associated to the LCDC
+Optional properties: + - max-bandwidth: The maximum pixels per second that the memory + interface / lcd controller combination can sustain + - max-width: The maximum horizontal pixel width supported by + the lcd controller. + - max-pixelclock: The maximum pixel clock that can be supported + by the lcd controller in KHz. + Example:
fb: fb@4830e000 { diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index 84fdf25..05f2b14 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -448,10 +448,29 @@ int tilcdc_crtc_mode_valid(struct drm_crtc *crtc, struct drm_display_mode *mode) if (mode->vdisplay > 2048) return MODE_VIRTUAL_Y;
+ /* + * some devices have a maximum allowed pixel clock + * configured from the DT + */ + if (mode->clock > priv->max_pixelclock) { + DBG("Pruning mode, pixel clock too high"); + return MODE_CLOCK_HIGH; + } + + /* + * some devices further limit the max horizontal resolution + * configured from the DT + */ + if (mode->hdisplay > priv->max_width) + return MODE_BAD_WIDTH; + /* filter out modes that would require too much memory bandwidth: */ - bandwidth = mode->hdisplay * mode->vdisplay * drm_mode_vrefresh(mode); - if (bandwidth > priv->max_bandwidth) + bandwidth = mode->hdisplay * mode->vdisplay * + drm_mode_vrefresh(mode); + if (bandwidth > priv->max_bandwidth) { + DBG("Pruning mode, exceeds defined bandwidth limit"); return MODE_BAD; + }
return MODE_OK; } diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c index f2a6528..1e8f273 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c @@ -212,7 +212,20 @@ static int tilcdc_load(struct drm_device *dev, unsigned long flags) #endif
if (of_property_read_u32(node, "max-bandwidth", &priv->max_bandwidth)) - priv->max_bandwidth = 1280 * 1024 * 60; + priv->max_bandwidth = TILCDC_DEFAULT_MAX_BANDWIDTH; + + DBG("Maximum Bandwidth Value %d", priv->max_bandwidth); + + if (of_property_read_u32(node, "ti,max-width", &priv->max_width)) + priv->max_width = TILCDC_DEFAULT_MAX_WIDTH; + + DBG("Maximum Horizontal Pixel Width Value %dpixels", priv->max_width); + + if (of_property_read_u32(node, "ti,max-pixelclock", + &priv->max_pixelclock)) + priv->max_pixelclock = TILCDC_DEFAULT_MAX_PIXELCLOCK; + + DBG("Maximum Pixel Clock Value %dKHz", priv->max_pixelclock);
pm_runtime_enable(dev->dev);
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.h b/drivers/gpu/drm/tilcdc/tilcdc_drv.h index 0906843..66df316 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.h +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.h @@ -34,6 +34,18 @@ #include <drm/drm_gem_cma_helper.h> #include <drm/drm_fb_cma_helper.h>
+/* Defaulting to pixel clock defined on AM335x */ +#define TILCDC_DEFAULT_MAX_PIXELCLOCK 126000 +/* Defaulting to max width as defined on AM335x */ +#define TILCDC_DEFAULT_MAX_WIDTH 2048 +/* + * This may need some tweaking, but want to allow at least 1280x1024@60 + * with optimized DDR & EMIF settings tweaked 1920x1080@24 appears to + * be supportable + */ +#define TILCDC_DEFAULT_MAX_BANDWIDTH (1280*1024*60) + + struct tilcdc_drm_private { void __iomem *mmio;
@@ -43,6 +55,16 @@ struct tilcdc_drm_private {
/* don't attempt resolutions w/ higher W * H * Hz: */ uint32_t max_bandwidth; + /* + * Pixel Clock will be restricted to some value as + * defined in the device datasheet measured in KHz + */ + uint32_t max_pixelclock; + /* + * Max allowable width is limited on a per device basis + * measured in pixels + */ + uint32_t max_width;
/* register contents saved across suspend/resume: */ u32 saved_register[12];