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| author | Rajendra Nayak <rnayak@ti.com> | 2009-05-28 14:43:06 +0200 |
|---|---|---|
| committer | Kevin Hilman <khilman@deeprootsystems.com> | 2010-02-23 20:05:05 +0100 |
| commit | a89b6f006201469a74dfc0cc4e953648b6a1c69d (patch) | |
| tree | 45fcb38420022f1d8cc4a77c2420f35fd0f3612a /arch/arm/mach-omap2/sleep34xx.S | |
| parent | OMAP3: RX-51: Pass cpu idle parameters (diff) | |
| download | linux-a89b6f006201469a74dfc0cc4e953648b6a1c69d.tar.xz linux-a89b6f006201469a74dfc0cc4e953648b6a1c69d.zip | |
OMAP3: PM: add scratchpad locking function
This patch implements locking using the semaphore in scratchpad
memory preventing any concurrent access to scratchpad from OMAP
and Baseband/Modem processor.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Diffstat (limited to 'arch/arm/mach-omap2/sleep34xx.S')
| -rw-r--r-- | arch/arm/mach-omap2/sleep34xx.S | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S index 22fcc14e63be..12a8ba0e0a3c 100644 --- a/arch/arm/mach-omap2/sleep34xx.S +++ b/arch/arm/mach-omap2/sleep34xx.S @@ -33,6 +33,8 @@ #include "prm.h" #include "sdrc.h" +#define SDRC_SCRATCHPAD_SEM_V 0xfa00291c + #define PM_PREPWSTST_CORE_V OMAP34XX_PRM_REGADDR(CORE_MOD, \ OMAP3430_PM_PREPWSTST) #define PM_PREPWSTST_CORE_P 0x48306AE8 @@ -57,6 +59,37 @@ #define SDRC_DLLA_STATUS_V OMAP34XX_SDRC_REGADDR(SDRC_DLLA_STATUS) #define SDRC_DLLA_CTRL_V OMAP34XX_SDRC_REGADDR(SDRC_DLLA_CTRL) + .text +/* Function to aquire the semaphore in scratchpad */ +ENTRY(lock_scratchpad_sem) + stmfd sp!, {lr} @ save registers on stack +wait_sem: + mov r0,#1 + ldr r1, sdrc_scratchpad_sem +wait_loop: + ldr r2, [r1] @ load the lock value + cmp r2, r0 @ is the lock free ? + beq wait_loop @ not free... + swp r2, r0, [r1] @ semaphore free so lock it and proceed + cmp r2, r0 @ did we succeed ? + beq wait_sem @ no - try again + ldmfd sp!, {pc} @ restore regs and return +sdrc_scratchpad_sem: + .word SDRC_SCRATCHPAD_SEM_V +ENTRY(lock_scratchpad_sem_sz) + .word . - lock_scratchpad_sem + + .text +/* Function to release the scratchpad semaphore */ +ENTRY(unlock_scratchpad_sem) + stmfd sp!, {lr} @ save registers on stack + ldr r3, sdrc_scratchpad_sem + mov r2,#0 + str r2,[r3] + ldmfd sp!, {pc} @ restore regs and return +ENTRY(unlock_scratchpad_sem_sz) + .word . - unlock_scratchpad_sem + .text /* Function call to get the restore pointer for resume from OFF */ ENTRY(get_restore_pointer) |