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-rw-r--r--arch/arm/mach-omap2/sram34xx.S129
1 files changed, 67 insertions, 62 deletions
diff --git a/arch/arm/mach-omap2/sram34xx.S b/arch/arm/mach-omap2/sram34xx.S
index 2c71461..c080c825 100644
--- a/arch/arm/mach-omap2/sram34xx.S
+++ b/arch/arm/mach-omap2/sram34xx.S
@@ -40,69 +40,74 @@
/*
* Change frequency of core dpll
* r0 = sdrc_rfr_ctrl r1 = sdrc_actim_ctrla r2 = sdrc_actim_ctrlb r3 = M2
+ * r4 = Unlock SDRC DLL? (1 = yes, 0 = no) -- only unlock DLL for
+ * SDRC rates < 83MHz
*/
ENTRY(omap3_sram_configure_core_dpll)
stmfd sp!, {r1-r12, lr} @ store regs to stack
+ ldr r4, [sp, #52] @ pull extra args off the stack
+ dsb @ flush buffered writes to interconnect
cmp r3, #0x2
blne configure_sdrc
- cmp r3, #0x2
+ cmp r4, #0x1
+ bleq unlock_dll
blne lock_dll
- cmp r3, #0x1
- blne unlock_dll
bl sdram_in_selfrefresh @ put the SDRAM in self refresh
bl configure_core_dpll
bl enable_sdrc
- cmp r3, #0x1
- blne wait_dll_unlock
- cmp r3, #0x2
+ cmp r4, #0x1
+ bleq wait_dll_unlock
blne wait_dll_lock
cmp r3, #0x1
blne configure_sdrc
+ isb @ prevent speculative exec past here
mov r0, #0 @ return value
ldmfd sp!, {r1-r12, pc} @ restore regs and return
unlock_dll:
- ldr r4, omap3_sdrc_dlla_ctrl
- ldr r5, [r4]
- orr r5, r5, #0x4
- str r5, [r4]
+ ldr r11, omap3_sdrc_dlla_ctrl
+ ldr r12, [r11]
+ orr r12, r12, #0x4
+ str r12, [r11] @ (no OCP barrier needed)
bx lr
lock_dll:
- ldr r4, omap3_sdrc_dlla_ctrl
- ldr r5, [r4]
- bic r5, r5, #0x4
- str r5, [r4]
+ ldr r11, omap3_sdrc_dlla_ctrl
+ ldr r12, [r11]
+ bic r12, r12, #0x4
+ str r12, [r11] @ (no OCP barrier needed)
bx lr
sdram_in_selfrefresh:
- mov r5, #0x0 @ Move 0 to R5
- mcr p15, 0, r5, c7, c10, 5 @ memory barrier
- ldr r4, omap3_sdrc_power @ read the SDRC_POWER register
- ldr r5, [r4] @ read the contents of SDRC_POWER
- orr r5, r5, #0x40 @ enable self refresh on idle req
- str r5, [r4] @ write back to SDRC_POWER register
- ldr r4, omap3_cm_iclken1_core @ read the CM_ICLKEN1_CORE reg
- ldr r5, [r4]
- bic r5, r5, #0x2 @ disable iclk bit for SRDC
- str r5, [r4]
+ ldr r11, omap3_sdrc_power @ read the SDRC_POWER register
+ ldr r12, [r11] @ read the contents of SDRC_POWER
+ mov r9, r12 @ keep a copy of SDRC_POWER bits
+ orr r12, r12, #0x40 @ enable self refresh on idle req
+ bic r12, r12, #0x4 @ clear PWDENA
+ str r12, [r11] @ write back to SDRC_POWER register
+ ldr r12, [r11] @ posted-write barrier for SDRC
+ ldr r11, omap3_cm_iclken1_core @ read the CM_ICLKEN1_CORE reg
+ ldr r12, [r11]
+ bic r12, r12, #0x2 @ disable iclk bit for SDRC
+ str r12, [r11]
wait_sdrc_idle:
- ldr r4, omap3_cm_idlest1_core
- ldr r5, [r4]
- and r5, r5, #0x2 @ check for SDRC idle
- cmp r5, #2
+ ldr r11, omap3_cm_idlest1_core
+ ldr r12, [r11]
+ and r12, r12, #0x2 @ check for SDRC idle
+ cmp r12, #2
bne wait_sdrc_idle
bx lr
configure_core_dpll:
- ldr r4, omap3_cm_clksel1_pll
- ldr r5, [r4]
- ldr r6, core_m2_mask_val @ modify m2 for core dpll
- and r5, r5, r6
- orr r5, r5, r3, lsl #0x1B @ r3 contains the M2 val
- str r5, [r4]
- mov r5, #0x800 @ wait for the clock to stabilise
+ ldr r11, omap3_cm_clksel1_pll
+ ldr r12, [r11]
+ ldr r10, core_m2_mask_val @ modify m2 for core dpll
+ and r12, r12, r10
+ orr r12, r12, r3, lsl #0x1B @ r3 contains the M2 val
+ str r12, [r11]
+ ldr r12, [r11] @ posted-write barrier for CM
+ mov r12, #0x800 @ wait for the clock to stabilise
cmp r3, #2
bne wait_clk_stable
bx lr
wait_clk_stable:
- subs r5, r5, #1
+ subs r12, r12, #1
bne wait_clk_stable
nop
nop
@@ -116,42 +121,42 @@ wait_clk_stable:
nop
bx lr
enable_sdrc:
- ldr r4, omap3_cm_iclken1_core
- ldr r5, [r4]
- orr r5, r5, #0x2 @ enable iclk bit for SDRC
- str r5, [r4]
+ ldr r11, omap3_cm_iclken1_core
+ ldr r12, [r11]
+ orr r12, r12, #0x2 @ enable iclk bit for SDRC
+ str r12, [r11]
wait_sdrc_idle1:
- ldr r4, omap3_cm_idlest1_core
- ldr r5, [r4]
- and r5, r5, #0x2
- cmp r5, #0
+ ldr r11, omap3_cm_idlest1_core
+ ldr r12, [r11]
+ and r12, r12, #0x2
+ cmp r12, #0
bne wait_sdrc_idle1
- ldr r4, omap3_sdrc_power
- ldr r5, [r4]
- bic r5, r5, #0x40
- str r5, [r4]
+restore_sdrc_power_val:
+ ldr r11, omap3_sdrc_power
+ str r9, [r11] @ restore SDRC_POWER, no barrier needed
bx lr
wait_dll_lock:
- ldr r4, omap3_sdrc_dlla_status
- ldr r5, [r4]
- and r5, r5, #0x4
- cmp r5, #0x4
+ ldr r11, omap3_sdrc_dlla_status
+ ldr r12, [r11]
+ and r12, r12, #0x4
+ cmp r12, #0x4
bne wait_dll_lock
bx lr
wait_dll_unlock:
- ldr r4, omap3_sdrc_dlla_status
- ldr r5, [r4]
- and r5, r5, #0x4
- cmp r5, #0x0
+ ldr r11, omap3_sdrc_dlla_status
+ ldr r12, [r11]
+ and r12, r12, #0x4
+ cmp r12, #0x0
bne wait_dll_unlock
bx lr
configure_sdrc:
- ldr r4, omap3_sdrc_rfr_ctrl
- str r0, [r4]
- ldr r4, omap3_sdrc_actim_ctrla
- str r1, [r4]
- ldr r4, omap3_sdrc_actim_ctrlb
- str r2, [r4]
+ ldr r11, omap3_sdrc_rfr_ctrl
+ str r0, [r11]
+ ldr r11, omap3_sdrc_actim_ctrla
+ str r1, [r11]
+ ldr r11, omap3_sdrc_actim_ctrlb
+ str r2, [r11]
+ ldr r2, [r11] @ posted-write barrier for SDRC
bx lr
omap3_sdrc_power: