fbdev: sh_mobile_lcdcfb: add blanking support

Add a blanking callback to the LCDC driver in order to support both
FBIOBLANK and TIOCLINUX blanking ioctls. LCDC clocks are also released
if the requested blanking level is superior to FB_BLANK_NORMAL, to allow
runtime PM to disable the clocks if possible.

Signed-off-by: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 45 insertions, 0 deletions

diff --git a/drivers/video/sh_mobile_lcdcfb.c b/drivers/video/sh_mobile_lcdcfb.c
index e040e46d7d91..65c4ee3628c4 100644
--- a/drivers/video/sh_mobile_lcdcfb.c
+++ b/drivers/video/sh_mobile_lcdcfb.c
@@ -977,6 +977,49 @@ static int sh_mobile_check_var(struct fb_var_screeninfo *var, struct fb_info *in
         return 0;
 }
 
+/*
+ * Screen blanking. Behavior is as follows:
+ * FB_BLANK_UNBLANK: screen unblanked, clocks enabled
+ * FB_BLANK_NORMAL: screen blanked, clocks enabled
+ * FB_BLANK_VSYNC,
+ * FB_BLANK_HSYNC,
+ * FB_BLANK_POWEROFF: screen blanked, clocks disabled
+ */
+static int sh_mobile_lcdc_blank(int blank, struct fb_info *info)
+{
+        struct sh_mobile_lcdc_chan *ch = info->par;
+        struct sh_mobile_lcdc_priv *p = ch->lcdc;
+
+        /* blank the screen? */
+        if (blank > FB_BLANK_UNBLANK && ch->blank_status == FB_BLANK_UNBLANK) {
+                struct fb_fillrect rect = {
+                        .width = info->var.xres,
+                        .height = info->var.yres,
+                };
+                sh_mobile_lcdc_fillrect(info, &rect);
+        }
+        /* turn clocks on? */
+        if (blank <= FB_BLANK_NORMAL && ch->blank_status > FB_BLANK_NORMAL) {
+                sh_mobile_lcdc_clk_on(p);
+        }
+        /* turn clocks off? */
+        if (blank > FB_BLANK_NORMAL && ch->blank_status <= FB_BLANK_NORMAL) {
+                /* make sure the screen is updated with the black fill before
+                 * switching the clocks off. one vsync is not enough since
+                 * blanking may occur in the middle of a refresh. deferred io
+                 * mode will reenable the clocks and update the screen in time,
+                 * so it does not need this. */
+                if (!info->fbdefio) {
+                        sh_mobile_wait_for_vsync(info);
+                        sh_mobile_wait_for_vsync(info);
+                }
+                sh_mobile_lcdc_clk_off(p);
+        }
+
+        ch->blank_status = blank;
+        return 0;
+}
+
 static struct fb_ops sh_mobile_lcdc_ops = {
         .owner          = THIS_MODULE,
         .fb_setcolreg   = sh_mobile_lcdc_setcolreg,
@@ -985,6 +1028,7 @@ static struct fb_ops sh_mobile_lcdc_ops = {
         .fb_fillrect    = sh_mobile_lcdc_fillrect,
         .fb_copyarea    = sh_mobile_lcdc_copyarea,
         .fb_imageblit   = sh_mobile_lcdc_imageblit,
+        .fb_blank       = sh_mobile_lcdc_blank,
         .fb_pan_display = sh_mobile_fb_pan_display,
         .fb_ioctl       = sh_mobile_ioctl,
         .fb_open        = sh_mobile_open,
diff --git a/drivers/video/sh_mobile_lcdcfb.h b/drivers/video/sh_mobile_lcdcfb.h
index 03a22dcbcc59..fad353a7e44c 100644
--- a/drivers/video/sh_mobile_lcdcfb.h
+++ b/drivers/video/sh_mobile_lcdcfb.h
@@ -37,6 +37,7 @@ struct sh_mobile_lcdc_chan {
         struct completion vsync_completion;
         struct fb_var_screeninfo display_var;
         int use_count;
+        int blank_status;
         struct mutex open_lock;         /* protects the use counter */
 };