atmel_lcdfb: suspend/resume support

Teach atmel_lcdfb driver how to suspend/resume.

Note that the backlight control should probably do more of the same stuff:
turning off display power (more than just the backlight) and stopping the
clocks (and dma to drive the no-longer-seen display).  No point in wasting
power to generate images that can't be observed, after all...

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <avictor.za@gmail.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 35 insertions, 2 deletions

diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
index 4d68b1b880d..6fcf76c1291 100644
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c
@@ -909,10 +909,42 @@ static int __exit atmel_lcdfb_remove(struct platform_device *pdev)
         return 0;
 }
 
+#ifdef CONFIG_PM
+
+static int atmel_lcdfb_suspend(struct platform_device *pdev, pm_message_t mesg)
+{
+        struct fb_info *info = platform_get_drvdata(pdev);
+        struct atmel_lcdfb_info *sinfo = info->par;
+
+        sinfo->saved_lcdcon = lcdc_readl(sinfo, ATMEL_LCDC_CONTRAST_VAL);
+        lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, 0);
+        if (sinfo->atmel_lcdfb_power_control)
+                sinfo->atmel_lcdfb_power_control(0);
+        atmel_lcdfb_stop_clock(sinfo);
+        return 0;
+}
+
+static int atmel_lcdfb_resume(struct platform_device *pdev)
+{
+        struct fb_info *info = platform_get_drvdata(pdev);
+        struct atmel_lcdfb_info *sinfo = info->par;
+
+        atmel_lcdfb_start_clock(sinfo);
+        if (sinfo->atmel_lcdfb_power_control)
+                sinfo->atmel_lcdfb_power_control(1);
+        lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, sinfo->saved_lcdcon);
+        return 0;
+}
+
+#else
+#define atmel_lcdfb_suspend     NULL
+#define atmel_lcdfb_resume      NULL
+#endif
+
 static struct platform_driver atmel_lcdfb_driver = {
         .remove         = __exit_p(atmel_lcdfb_remove),
-
-// FIXME need suspend, resume
+        .suspend        = atmel_lcdfb_suspend,
+        .resume         = atmel_lcdfb_resume,
 
         .driver         = {
                 .name   = "atmel_lcdfb",
diff --git a/include/video/atmel_lcdc.h b/include/video/atmel_lcdc.h
index 336c20db87f..2fd9fad922e 100644
--- a/include/video/atmel_lcdc.h
+++ b/include/video/atmel_lcdc.h
@@ -39,6 +39,7 @@ struct atmel_lcdfb_info {
         u8                      bl_power;
 #endif
         bool                    lcdcon_is_backlight;
+        u8                      saved_lcdcon;
 
         u8                      default_bpp;
         unsigned int            default_lcdcon2;