drm/bridge: tfp410: add pclk limits

Add pixel clock limits to the driver as per TFP410 datasheet: min 25MHz,
max 165MHz.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200121094655.9092-1-tomi.valkeinen@ti.com

diff --git a/drivers/gpu/drm/bridge/ti-tfp410.c b/drivers/gpu/drm/bridge/ti-tfp410.c
index 6f6d6d1..108e8cd 100644 (file)
--- a/drivers/gpu/drm/bridge/ti-tfp410.c
+++ b/drivers/gpu/drm/bridge/ti-tfp410.c
@@ -167,10 +167,23 @@ static void tfp410_disable(struct drm_bridge *bridge)
        gpiod_set_value_cansleep(dvi->powerdown, 1);
 }
 
+static enum drm_mode_status tfp410_mode_valid(struct drm_bridge *bridge,
+                                             const struct drm_display_mode *mode)
+{
+       if (mode->clock < 25000)
+               return MODE_CLOCK_LOW;
+
+       if (mode->clock > 165000)
+               return MODE_CLOCK_HIGH;
+
+       return MODE_OK;
+}
+
 static const struct drm_bridge_funcs tfp410_bridge_funcs = {
        .attach         = tfp410_attach,
        .enable         = tfp410_enable,
        .disable        = tfp410_disable,
+       .mode_valid     = tfp410_mode_valid,
 };
 
 static void tfp410_hpd_work_func(struct work_struct *work)