drm/pl111: Add optional variant display en/disable callbacks

The silcon and components around the PL111 may require some
variants to perform special set-up of the display. Add two
callbacks to manage this.
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-6-linus.walleij@linaro.org

drivers/gpu/drm/pl111/pl111_display.c

@@ -208,6 +208,9 @@ static void pl111_display_enable(struct drm_simple_display_pipe *pipe,
 	 */
 	msleep(20);
 
+	if (priv->variant_display_enable)
+		priv->variant_display_enable(drm, fb->format->format);
+
 	/* Power Up */
 	cntl |= CNTL_LCDPWR;
 	writel(cntl, priv->regs + priv->ctrl);
@@ -237,6 +240,9 @@ void pl111_display_disable(struct drm_simple_display_pipe *pipe)
 	 */
 	msleep(20);
 
+	if (priv->variant_display_disable)
+		priv->variant_display_disable(drm);
+
 	/* Disable */
 	writel(0, priv->regs + priv->ctrl);
 

drivers/gpu/drm/pl111/pl111_drm.h

@@ -26,6 +26,7 @@
 #include <drm/drm_panel.h>
 #include <drm/drm_bridge.h>
 #include <linux/clk-provider.h>
+#include <linux/interrupt.h>
 
 #define CLCD_IRQ_NEXTBASE_UPDATE BIT(2)
 
@@ -66,6 +67,8 @@ struct pl111_drm_dev_private {
 	 */
 	spinlock_t tim2_lock;
 	const struct pl111_variant_data *variant;
+	void (*variant_display_enable) (struct drm_device *drm, u32 format);
+	void (*variant_display_disable) (struct drm_device *drm);
 };
 
 int pl111_display_init(struct drm_device *dev);