[PATCH 2/7] drm/panel: add pre_enable routine to drm panel

[Ajay Kumar <ajaykumar.rs@samsung.com>]

Most of the panels need an init sequence as mentioned below:
	-- poweron LCD unit/LCD_EN
	-- start video data
	-- poweron LED unit/BL_EN
With existing callbacks for drm panel, we cannot accomodate such
panels, since only one callback, i.e "panel_enable" is supported.

This patch adds a "pre_enable" callback which can be called before
the actual video data is on, and then call the "enable" callback
after the video data is available.

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
---
 include/drm/drm_panel.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index c2ab77a..89210bf 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -32,6 +32,7 @@ struct drm_panel;
 
 struct drm_panel_funcs {
 	int (*disable)(struct drm_panel *panel);
+	int (*pre_enable)(struct drm_panel *panel);
 	int (*enable)(struct drm_panel *panel);
 	int (*get_modes)(struct drm_panel *panel);
 };
@@ -54,6 +55,14 @@ static inline int drm_panel_disable(struct drm_panel *panel)
 	return panel ? -ENOSYS : -EINVAL;
 }
 
+static inline int drm_panel_pre_enable(struct drm_panel *panel)
+{
+	if (panel && panel->funcs && panel->funcs->pre_enable)
+		return panel->funcs->pre_enable(panel);
+
+	return panel ? -ENOSYS : -EINVAL;
+}
+
 static inline int drm_panel_enable(struct drm_panel *panel)
 {
 	if (panel && panel->funcs && panel->funcs->enable)
-- 
1.8.1.2