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ARM: mach-shmobile: sh7372 generic suspend/resume support
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Convert the sh7372 Core Standby code to make use
of the new generic ARM cpu suspend/resume code.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Magnus Damm authored and Rafael J. Wysocki committed Sep 25, 2011
1 parent 0aa2a22 commit 06b8416
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Showing 3 changed files with 23 additions and 246 deletions.
3 changes: 1 addition & 2 deletions arch/arm/mach-shmobile/include/mach/common.h
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Expand Up @@ -35,8 +35,7 @@ extern void sh7372_add_standard_devices(void);
extern void sh7372_clock_init(void);
extern void sh7372_pinmux_init(void);
extern void sh7372_pm_init(void);
extern void sh7372_cpu_suspend(void);
extern void sh7372_cpu_resume(void);
extern void sh7372_resume_core_standby(void);
extern struct clk sh7372_extal1_clk;
extern struct clk sh7372_extal2_clk;

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36 changes: 16 additions & 20 deletions arch/arm/mach-shmobile/pm-sh7372.c
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Expand Up @@ -21,6 +21,7 @@
#include <asm/system.h>
#include <asm/io.h>
#include <asm/tlbflush.h>
#include <asm/suspend.h>
#include <mach/common.h>
#include <mach/sh7372.h>

Expand Down Expand Up @@ -152,30 +153,25 @@ struct sh7372_pm_domain sh7372_a3sg = {

#endif /* CONFIG_PM */

static void sh7372_enter_core_standby(void)
static int sh7372_do_idle_core_standby(unsigned long unused)
{
void __iomem *smfram = (void __iomem *)SMFRAM;

__raw_writel(0, APARMBAREA); /* translate 4k */
__raw_writel(__pa(sh7372_cpu_resume), SBAR); /* set reset vector */
__raw_writel(0x10, SYSTBCR); /* enable core standby */

__raw_writel(0, smfram + 0x3c); /* clear page table address */

sh7372_cpu_suspend();
cpu_init();
cpu_do_idle(); /* WFI when SYSTBCR == 0x10 -> Core Standby */
return 0;
}

/* if page table address is non-NULL then we have been powered down */
if (__raw_readl(smfram + 0x3c)) {
__raw_writel(__raw_readl(smfram + 0x40),
__va(__raw_readl(smfram + 0x3c)));
static void sh7372_enter_core_standby(void)
{
/* set reset vector, translate 4k */
__raw_writel(__pa(sh7372_resume_core_standby), SBAR);
__raw_writel(0, APARMBAREA);

flush_tlb_all();
set_cr(__raw_readl(smfram + 0x38));
}
/* enter sleep mode with SYSTBCR to 0x10 */
__raw_writel(0x10, SYSTBCR);
cpu_suspend(0, sh7372_do_idle_core_standby);
__raw_writel(0, SYSTBCR);

__raw_writel(0, SYSTBCR); /* disable core standby */
__raw_writel(0, SBAR); /* disable reset vector translation */
/* disable reset vector translation */
__raw_writel(0, SBAR);
}

#ifdef CONFIG_CPU_IDLE
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230 changes: 6 additions & 224 deletions arch/arm/mach-shmobile/sleep-sh7372.S
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Expand Up @@ -30,231 +30,13 @@
*/

#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/memory.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
.global sh7372_resume_core_standby
sh7372_resume_core_standby:
ldr pc, 1f
1: .long cpu_resume - PAGE_OFFSET + PLAT_PHYS_OFFSET

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