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Commit a89b6f00 authored by Rajendra Nayak's avatar Rajendra Nayak Committed by Kevin Hilman
Browse files

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: default avatarRajendra Nayak <rnayak@ti.com>
Signed-off-by: default avatarKevin Hilman <khilman@deeprootsystems.com>
parent 5a1b1d3a

arch/arm/mach-omap2/sleep34xx.S

+33 −0
Original line number Diff line number Diff line
@@ -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)