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Diffstat (limited to 'arch/arm/mach-shmobile/sleep-sh7372.S')
| -rw-r--r-- | arch/arm/mach-shmobile/sleep-sh7372.S | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/sleep-sh7372.S b/arch/arm/mach-shmobile/sleep-sh7372.S new file mode 100644 index 00000000000..d37d3ca4d18 --- /dev/null +++ b/arch/arm/mach-shmobile/sleep-sh7372.S @@ -0,0 +1,260 @@ +/* + * sh7372 lowlevel sleep code for "Core Standby Mode" + * + * Copyright (C) 2011 Magnus Damm + * + * In "Core Standby Mode" the ARM core is off, but L2 cache is still on + * + * Based on mach-omap2/sleep34xx.S + * + * (C) Copyright 2007 Texas Instruments + * Karthik Dasu <karthik-dp@ti.com> + * + * (C) Copyright 2004 Texas Instruments, <www.ti.com> + * Richard Woodruff <r-woodruff2@ti.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> + +#define SMFRAM 0xe6a70000 + + .align +kernel_flush: + .word v7_flush_dcache_all + + .align 3 +ENTRY(sh7372_cpu_suspend) + stmfd sp!, {r0-r12, lr} @ save registers on stack + + ldr r8, =SMFRAM + + mov r4, sp @ Store sp + mrs r5, spsr @ Store spsr + mov r6, lr @ Store lr + stmia r8!, {r4-r6} + + mrc p15, 0, r4, c1, c0, 2 @ Coprocessor access control register + mrc p15, 0, r5, c2, c0, 0 @ TTBR0 + mrc p15, 0, r6, c2, c0, 1 @ TTBR1 + mrc p15, 0, r7, c2, c0, 2 @ TTBCR + stmia r8!, {r4-r7} + + mrc p15, 0, r4, c3, c0, 0 @ Domain access Control Register + mrc p15, 0, r5, c10, c2, 0 @ PRRR + mrc p15, 0, r6, c10, c2, 1 @ NMRR + stmia r8!,{r4-r6} + + mrc p15, 0, r4, c13, c0, 1 @ Context ID + mrc p15, 0, r5, c13, c0, 2 @ User r/w thread and process ID + mrc p15, 0, r6, c12, c0, 0 @ Secure or NS vector base address + mrs r7, cpsr @ Store current cpsr + stmia r8!, {r4-r7} + + mrc p15, 0, r4, c1, c0, 0 @ save control register + stmia r8!, {r4} + + /* + * jump out to kernel flush routine + * - reuse that code is better + * - it executes in a cached space so is faster than refetch per-block + * - should be faster and will change with kernel + * - 'might' have to copy address, load and jump to it + * Flush all data from the L1 data cache before disabling + * SCTLR.C bit. + */ + ldr r1, kernel_flush + mov lr, pc + bx r1 + + /* + * Clear the SCTLR.C bit to prevent further data cache + * allocation. Clearing SCTLR.C would make all the data accesses + * strongly ordered and would not hit the cache. + */ + mrc p15, 0, r0, c1, c0, 0 + bic r0, r0, #(1 << 2) @ Disable the C bit + mcr p15, 0, r0, c1, c0, 0 + isb + + /* + * Invalidate L1 data cache. Even though only invalidate is + * necessary exported flush API is used here. Doing clean + * on already clean cache would be almost NOP. + */ + ldr r1, kernel_flush + blx r1 + /* + * The kernel doesn't interwork: v7_flush_dcache_all in particluar will + * always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled. + * This sequence switches back to ARM. Note that .align may insert a + * nop: bx pc needs to be word-aligned in order to work. + */ + THUMB( .thumb ) + THUMB( .align ) + THUMB( bx pc ) + THUMB( nop ) + .arm + + /* Data memory barrier and Data sync barrier */ + dsb + dmb + +/* + * =================================== + * == WFI instruction => Enter idle == + * =================================== + */ + wfi @ wait for interrupt + +/* + * =================================== + * == Resume path for non-OFF modes == + * =================================== + */ + mrc p15, 0, r0, c1, c0, 0 + tst r0, #(1 << 2) @ Check C bit enabled? + orreq r0, r0, #(1 << 2) @ Enable the C bit if cleared + mcreq p15, 0, r0, c1, c0, 0 + isb + +/* + * =================================== + * == Exit point from non-OFF modes == + * =================================== + */ + ldmfd sp!, {r0-r12, pc} @ restore regs and return + + .pool + + .align 12 + .text + .global sh7372_cpu_resume +sh7372_cpu_resume: + + mov r1, #0 + /* + * Invalidate all instruction caches to PoU + * and flush branch target cache + */ + mcr p15, 0, r1, c7, c5, 0 + + ldr r3, =SMFRAM + + ldmia r3!, {r4-r6} + mov sp, r4 @ Restore sp + msr spsr_cxsf, r5 @ Restore spsr + mov lr, r6 @ Restore lr + + ldmia r3!, {r4-r7} + mcr p15, 0, r4, c1, c0, 2 @ Coprocessor access Control Register + mcr p15, 0, r5, c2, c0, 0 @ TTBR0 + mcr p15, 0, r6, c2, c0, 1 @ TTBR1 + mcr p15, 0, r7, c2, c0, 2 @ TTBCR + + ldmia r3!,{r4-r6} + mcr p15, 0, r4, c3, c0, 0 @ Domain access Control Register + mcr p15, 0, r5, c10, c2, 0 @ PRRR + mcr p15, 0, r6, c10, c2, 1 @ NMRR + + ldmia r3!,{r4-r7} + mcr p15, 0, r4, c13, c0, 1 @ Context ID + mcr p15, 0, r5, c13, c0, 2 @ User r/w thread and process ID + mrc p15, 0, r6, c12, c0, 0 @ Secure or NS vector base address + msr cpsr, r7 @ store cpsr + + /* Starting to enable MMU here */ + mrc p15, 0, r7, c2, c0, 2 @ Read TTBRControl + /* Extract N (0:2) bits and decide whether to use TTBR0 or TTBR1 */ + and r7, #0x7 + cmp r7, #0x0 + beq usettbr0 +ttbr_error: + /* + * More work needs to be done to support N[0:2] value other than 0 + * So looping here so that the error can be detected + */ + b ttbr_error + + .align +cache_pred_disable_mask: + .word 0xFFFFE7FB +ttbrbit_mask: + .word 0xFFFFC000 +table_index_mask: + .word 0xFFF00000 +table_entry: + .word 0x00000C02 +usettbr0: + + mrc p15, 0, r2, c2, c0, 0 + ldr r5, ttbrbit_mask + and r2, r5 + mov r4, pc + ldr r5, table_index_mask + and r4, r5 @ r4 = 31 to 20 bits of pc + /* Extract the value to be written to table entry */ + ldr r6, table_entry + /* r6 has the value to be written to table entry */ + add r6, r6, r4 + /* Getting the address of table entry to modify */ + lsr r4, #18 + /* r2 has the location which needs to be modified */ + add r2, r4 + ldr r4, [r2] + str r6, [r2] /* modify the table entry */ + + mov r7, r6 + mov r5, r2 + mov r6, r4 + /* r5 = original page table address */ + /* r6 = original page table data */ + + mov r0, #0 + mcr p15, 0, r0, c7, c5, 4 @ Flush prefetch buffer + mcr p15, 0, r0, c7, c5, 6 @ Invalidate branch predictor array + mcr p15, 0, r0, c8, c5, 0 @ Invalidate instruction TLB + mcr p15, 0, r0, c8, c6, 0 @ Invalidate data TLB + + /* + * Restore control register. This enables the MMU. + * The caches and prediction are not enabled here, they + * will be enabled after restoring the MMU table entry. + */ + ldmia r3!, {r4} + stmia r3!, {r5} /* save original page table address */ + stmia r3!, {r6} /* save original page table data */ + stmia r3!, {r7} /* save modified page table data */ + + ldr r2, cache_pred_disable_mask + and r4, r2 + mcr p15, 0, r4, c1, c0, 0 + dsb + isb + + ldr r0, =restoremmu_on + bx r0 + +/* + * ============================== + * == Exit point from OFF mode == + * ============================== + */ +restoremmu_on: + + ldmfd sp!, {r0-r12, pc} @ restore regs and return |