[PATCH RFC] davinci: poll for sleep completion in resume routine.

From: Vishwanathrao Badarkhe, Manish
Date: Thu Jan 31 2013 - 04:33:15 EST


As per OMAP-L138 TRM, Software must poll for
SLEEPCOMPLETE bit until it is set to 1 before clearing
SLEEPENABLE bit in DEEPSLEEP register in resume routine.
Modifications are as per datasheet:
http://www.ti.com/lit/ug/spruh77a/spruh77a.pdf
See sections 10.10.2.2 and 11.5.21 for more detailed
explanation.

Tested on da850-evm.

Signed-off-by: Vishwanathrao Badarkhe, Manish <manishv.b@xxxxxx>
---
:100644 100644 d4e9316... 976f096... M arch/arm/mach-davinci/sleep.S
arch/arm/mach-davinci/sleep.S | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-davinci/sleep.S b/arch/arm/mach-davinci/sleep.S
index d4e9316..976f096 100644
--- a/arch/arm/mach-davinci/sleep.S
+++ b/arch/arm/mach-davinci/sleep.S
@@ -35,6 +35,7 @@
#define PLL_LOCK_CYCLES (PLL_LOCK_TIME * 25)

#define DEEPSLEEP_SLEEPENABLE_BIT BIT(31)
+#define DEEPSLEEP_SLEEPCOMPLETE_BIT BIT(30)

.text
/*
@@ -110,6 +111,13 @@ ENTRY(davinci_cpu_suspend)

/* Wake up from sleep */

+ /* wait for sleep complete */
+sleep_complete:
+ ldr ip, [r4]
+ and ip, ip, #DEEPSLEEP_SLEEPCOMPLETE_BIT
+ cmp ip, #DEEPSLEEP_SLEEPCOMPLETE_BIT
+ bne sleep_complete
+
/* Clear sleep enable */
ldr ip, [r4]
bic ip, ip, #DEEPSLEEP_SLEEPENABLE_BIT
--
1.7.4.1

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