OMAP3630: PM: Erratum i608: disable RTA

Erratum id: i608
RTA (Retention Till Access) feature is not supported and leads to device
stability issues when enabled. This impacts modules with embedded memories
on OMAP3630

Workaround is to disable RTA on boot and coming out of core off.
For disabling RTA coming out of off mode, we do this by overriding the
restore pointer for 3630 as the first point of entry before caches are
touched and is common for GP and HS devices. To disable earlier than
this could be possible by modifying the PPA for HS devices, but not for
GP devices.

Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Tony Lindgren <tony@atomide.com>

Acked-by: Jean Pihet <j-pihet@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

[ambresh@ti.com: co-developer]
Signed-off-by: Ambresh K <ambresh@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S
index 24ecb0a5cce1..4abf447fddfc 100644
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -45,6 +45,8 @@
 #define CM_IDLEST_CKGEN_V       OMAP34XX_CM_REGADDR(PLL_MOD, CM_IDLEST)
 #define SRAM_BASE_P             0x40200000
 #define CONTROL_STAT            0x480022F0
+#define CONTROL_MEM_RTA_CTRL    (OMAP343X_CTRL_BASE\
+                                        + OMAP36XX_CONTROL_MEM_RTA_CTRL)
 #define SCRATCHPAD_MEM_OFFS     0x310 /* Move this as correct place is
                                        * available */
 #define SCRATCHPAD_BASE_P       (OMAP343X_CTRL_BASE + OMAP343X_CONTROL_MEM_WKUP\
@@ -99,6 +101,14 @@ ENTRY(get_restore_pointer)
         ldmfd   sp!, {pc}     @ restore regs and return
 ENTRY(get_restore_pointer_sz)
         .word   . - get_restore_pointer
+        .text
+/* Function call to get the restore pointer for 3630 resume from OFF */
+ENTRY(get_omap3630_restore_pointer)
+        stmfd   sp!, {lr}     @ save registers on stack
+        adr     r0, restore_3630
+        ldmfd   sp!, {pc}     @ restore regs and return
+ENTRY(get_omap3630_restore_pointer_sz)
+        .word   . - get_omap3630_restore_pointer
 
         .text
 /* Function call to get the restore pointer for for ES3 to resume from OFF */
@@ -246,6 +256,20 @@ copy_to_sram:
         bne     copy_to_sram
         ldr     r1, sram_base
         blx     r1
+        b       restore
+
+restore_3630:
+        /*b restore_es3630*/            @ Enable to debug restore code
+        ldr     r1, pm_prepwstst_core_p
+        ldr     r2, [r1]
+        and     r2, r2, #0x3
+        cmp     r2, #0x0        @ Check if previous power state of CORE is OFF
+        bne     restore
+        /* Disable RTA before giving control */
+        ldr     r1, control_mem_rta
+        mov     r2, #OMAP36XX_RTA_DISABLE
+        str     r2, [r1]
+        /* Fall thru for the remaining logic */
 restore:
         /* b restore*/  @ Enable to debug restore code
         /* Check what was the reason for mpu reset and store the reason in r9*/
@@ -651,6 +675,8 @@ cache_pred_disable_mask:
         .word   0xFFFFE7FB
 control_stat:
         .word   CONTROL_STAT
+control_mem_rta:
+        .word   CONTROL_MEM_RTA_CTRL
 kernel_flush:
         .word v7_flush_dcache_all
         /*