[PATCH 01/03] ARM: mach-shmobile: sh7372 generic suspend/resume support

[Magnus Damm <magnus.damm@gmail.com>]

From: Magnus Damm <damm@opensource.se>

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>
---

 arch/arm/mach-shmobile/include/mach/common.h |    3 
 arch/arm/mach-shmobile/pm-sh7372.c           |   38 +---
 arch/arm/mach-shmobile/sleep-sh7372.S        |  230 --------------------------
 3 files changed, 24 insertions(+), 247 deletions(-)

--- 0001/arch/arm/mach-shmobile/include/mach/common.h
+++ work/arch/arm/mach-shmobile/include/mach/common.h	2011-07-06 18:11:38.000000000 +0900
@@ -35,8 +35,7 @@ extern void sh7372_add_standard_devices(
 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;
 
--- 0001/arch/arm/mach-shmobile/pm-sh7372.c
+++ work/arch/arm/mach-shmobile/pm-sh7372.c	2011-07-06 18:34:40.000000000 +0900
@@ -18,6 +18,7 @@
 #include <asm/system.h>
 #include <asm/io.h>
 #include <asm/tlbflush.h>
+#include <asm/suspend.h>
 #include <mach/common.h>
 
 #define SMFRAM 0xe6a70000
@@ -25,30 +26,25 @@
 #define SBAR 0xe6180020
 #define APARMBAREA 0xe6f10020
 
-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();
-
-	/* 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)));
+	cpu_do_idle(); /* WFI when SYSTBCR = 0x10 -> Core Standby */
+	return 0;
+}
 
-		flush_tlb_all();
-		set_cr(__raw_readl(smfram + 0x38));
-	}
+static void sh7372_enter_core_standby(void)
+{
+	/* set reset vector, translate 4k */
+	__raw_writel(__pa(sh7372_resume_core_standby), SBAR);
+	__raw_writel(0, APARMBAREA);
+
+	/* 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
--- 0001/arch/arm/mach-shmobile/sleep-sh7372.S
+++ work/arch/arm/mach-shmobile/sleep-sh7372.S	2011-07-06 18:32:44.000000000 +0900
@@ -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