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Subject[PATCH] 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>
---

Many thanks to Matt Reimer for suggesting this.

The seeming demise of handhelds.org has removed any formal patch logs.
However the patches can still be viewed online:
2006 patch:
http://paste.lisp.org/display/31700
2007 patch:
http://osdir.com/ml/handhelds.linux.kernel/2007-02/msg00020.html

And the fully patched handhelds.org kernel is still available, e.g.:
http://www.linuxtogo.org/~goxboxlive/htcuniversal/Kernel/linux-2.6.21-hh20.tar.bz2

drivers/video/w100fb.c | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/drivers/video/w100fb.c b/drivers/video/w100fb.c
index 90a2e30..2f6b2b8 100644
--- 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);
}
}
--
1.7.3.4
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