video: w100fb: Reduce sleep mode battery discharge

In 2006 and 2007 the handhelds.org kernel w100fb driver was patched to
reduce sleep mode battery discharge. Unfortunately those two patches
never migrated to the mainline kernel.

Fortunately the function affected - w100_suspend() - has not changed
since; thus those patches still apply cleanly.

Applying those patches to linux-3.4-rc3 running on an HP iPAQ hx4700
reduces the sleep mode battery discharge from approximately 26 mA to
approximately 11 mA.

This patch combines those two patches into a single unified patch.

Signed-off-by: Paul Parsons <lost.distance@yahoo.com>
Cc: Matt Reimer <mreimer@sdgsystems.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

diff --git a/drivers/video/w100fb.c b/drivers/video/w100fb.c
index 90a2e30..2f6b2b8 100644 (file)
--- a/drivers/video/w100fb.c
+++ b/drivers/video/w100fb.c
@@ -1567,6 +1567,18 @@ static void w100_suspend(u32 mode)
                val = readl(remapped_regs + mmPLL_CNTL);
                val |= 0x00000004;  /* bit2=1 */
                writel(val, remapped_regs + mmPLL_CNTL);
+
+               writel(0x00000000, remapped_regs + mmLCDD_CNTL1);
+               writel(0x00000000, remapped_regs + mmLCDD_CNTL2);
+               writel(0x00000000, remapped_regs + mmGENLCD_CNTL1);
+               writel(0x00000000, remapped_regs + mmGENLCD_CNTL2);
+               writel(0x00000000, remapped_regs + mmGENLCD_CNTL3);
+
+               val = readl(remapped_regs + mmMEM_EXT_CNTL);
+               val |= 0xF0000000;
+               val &= ~(0x00000001);
+               writel(val, remapped_regs + mmMEM_EXT_CNTL);
+
                writel(0x0000001d, remapped_regs + mmPWRMGT_CNTL);
        }
 }