ARM: OMAP2+: sleep33/43xx: Make sleep actions configurable

Add an argument to the sleep33xx and sleep43xx code to allow us to set
flags to determine which portions of the code get called in order to use
the same code for multiple power saving modes. This patch allows us to
decide whether or not we flush and disable caches, save EMIF context,
put the memory into self refresh and disable the EMIF, and/or invoke
the wkup_m3 when entering into WFI.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 52 insertions, 4 deletions

diff --git a/arch/arm/mach-omap2/sleep43xx.S b/arch/arm/mach-omap2/sleep43xx.S
index 8903814a6677..cd7e95f48a73 100644
--- a/arch/arm/mach-omap2/sleep43xx.S
+++ b/arch/arm/mach-omap2/sleep43xx.S
@@ -9,7 +9,7 @@
 #include <generated/ti-pm-asm-offsets.h>
 #include <linux/linkage.h>
 #include <linux/ti-emif-sram.h>
-
+#include <linux/platform_data/pm33xx.h>
 #include <asm/assembler.h>
 #include <asm/hardware/cache-l2x0.h>
 #include <asm/memory.h>
@@ -22,6 +22,9 @@
 #include "prm33xx.h"
 #include "prcm43xx.h"
 
+/* replicated define because linux/bitops.h cannot be included in assembly */
+#define BIT(nr)			(1 << (nr))
+
 #define AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED		0x00030000
 #define AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE		0x0003
 #define AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE		0x0002
@@ -51,6 +54,12 @@
 ENTRY(am43xx_do_wfi)
 	stmfd	sp!, {r4 - r11, lr}	@ save registers on stack
 
+	/* Save wfi_flags arg to data space */
+	mov	r4, r0
+	adr	r3, am43xx_pm_ro_sram_data
+	ldr	r2, [r3, #AMX3_PM_RO_SRAM_DATA_VIRT_OFFSET]
+	str	r4, [r2, #AMX3_PM_WFI_FLAGS_OFFSET]
+
 #ifdef CONFIG_CACHE_L2X0
 	/* Retrieve l2 cache virt address BEFORE we shut off EMIF */
 	ldr	r1, get_l2cache_base
@@ -58,6 +67,10 @@ ENTRY(am43xx_do_wfi)
 	mov	r8, r0
 #endif
 
+	/* Only flush cache is we know we are losing MPU context */
+	tst	r4, #WFI_FLAG_FLUSH_CACHE
+	beq	cache_skip_flush
+
 	/*
 	 * Flush all data from the L1 and L2 data cache before disabling
 	 * SCTLR.C bit.
@@ -128,13 +141,33 @@ sync:
 	bne	sync
 #endif
 
+	/* Restore wfi_flags */
+	adr	r3, am43xx_pm_ro_sram_data
+	ldr	r2, [r3, #AMX3_PM_RO_SRAM_DATA_VIRT_OFFSET]
+	ldr	r4, [r2, #AMX3_PM_WFI_FLAGS_OFFSET]
+
+cache_skip_flush:
+	/* Check if we want self refresh */
+	tst	r4, #WFI_FLAG_SELF_REFRESH
+	beq	emif_skip_enter_sr
+
 	adr     r9, am43xx_emif_sram_table
 
 	ldr     r3, [r9, #EMIF_PM_ENTER_SR_OFFSET]
 	blx     r3
 
+emif_skip_enter_sr:
+	/* Only necessary if PER is losing context */
+	tst	r4, #WFI_FLAG_SAVE_EMIF
+	beq	emif_skip_save
+
 	ldr     r3, [r9, #EMIF_PM_SAVE_CONTEXT_OFFSET]
-	blx     r3
+	blx	r3
+
+emif_skip_save:
+	/* Only can disable EMIF if we have entered self refresh */
+	tst	r4, #WFI_FLAG_SELF_REFRESH
+	beq	emif_skip_disable
 
 	/* Disable EMIF */
 	ldr	r1, am43xx_virt_emif_clkctrl
@@ -148,6 +181,10 @@ wait_emif_disable:
 	cmp	r2, r3
 	bne	wait_emif_disable
 
+emif_skip_disable:
+	tst	r4, #WFI_FLAG_WAKE_M3
+	beq	wkup_m3_skip
+
 	/*
 	 * For the MPU WFI to be registered as an interrupt
 	 * to WKUP_M3, MPU_CLKCTRL.MODULEMODE needs to be set
@@ -165,6 +202,7 @@ wait_emif_disable:
 	mov	r2, #AM43XX_CM_CLKSTCTRL_CLKTRCTRL_SW_SLEEP
 	str	r2, [r1]
 
+wkup_m3_skip:
 	/*
 	 * Execute a barrier instruction to ensure that all cache,
 	 * TLB and branch predictor maintenance operations issued
@@ -218,6 +256,9 @@ wait_emif_enable:
 	cmp	r2, r3
 	bne	wait_emif_enable
 
+	tst	r4, #WFI_FLAG_FLUSH_CACHE
+	beq	cache_skip_restore
+
 	/*
 	 * Set SCTLR.C bit to allow data cache allocation
 	 */
@@ -226,9 +267,16 @@ wait_emif_enable:
 	mcr	p15, 0, r0, c1, c0, 0
 	isb
 
-	ldr     r1, [r9, #EMIF_PM_ABORT_SR_OFFSET]
-	blx     r1
+cache_skip_restore:
+	/* Only necessary if PER is losing context */
+	tst	r4, #WFI_FLAG_SELF_REFRESH
+	beq	emif_skip_exit_sr_abt
+
+	adr	r9, am43xx_emif_sram_table
+	ldr	r1, [r9, #EMIF_PM_ABORT_SR_OFFSET]
+	blx	r1
 
+emif_skip_exit_sr_abt:
 	/* Let the suspend code know about the abort */
 	mov	r0, #1
 	ldmfd	sp!, {r4 - r11, pc}	@ restore regs and return