Merge branch 'samsung_cpuidle_l2_retention' into linux-linaro-tracking

5 files changed, 230 insertions, 36 deletions

diff --git a/arch/arm/mach-exynos/cpu.c b/arch/arm/mach-exynos/cpu.c
index 699774cbf11..2679d1eb78f 100644
--- a/arch/arm/mach-exynos/cpu.c
+++ b/arch/arm/mach-exynos/cpu.c
@@ -18,6 +18,8 @@
 #include <asm/exception.h>
 #include <asm/hardware/cache-l2x0.h>
 #include <asm/hardware/gic.h>
+#include <asm/cacheflush.h>
+#include <mach/pmu.h>
 
 #include <plat/cpu.h>
 #include <plat/clock.h>
@@ -34,6 +36,9 @@
 #include <mach/regs-irq.h>
 #include <mach/regs-pmu.h>
 
+#define L2_AUX_VAL 0x7C470001
+#define L2_AUX_MASK 0xC200ffff
+
 extern int combiner_init(unsigned int combiner_nr, void __iomem *base,
 			 unsigned int irq_start);
 extern void combiner_cascade_irq(unsigned int combiner_nr, unsigned int irq);
@@ -241,22 +246,49 @@ core_initcall(exynos4_core_init);
 #ifdef CONFIG_CACHE_L2X0
 static int __init exynos4_l2x0_cache_init(void)
 {
-	/* TAG, Data Latency Control: 2cycle */
-	__raw_writel(0x110, S5P_VA_L2CC + L2X0_TAG_LATENCY_CTRL);
+#ifdef CONFIG_OF
+	int ret;
+	ret = l2x0_of_init(L2_AUX_VAL, L2_AUX_MASK);
+	if (!ret) {
+		l2x0_regs_phys = virt_to_phys(&l2x0_saved_regs);
+		clean_dcache_area(&l2x0_regs_phys, sizeof(unsigned long));
+		return 0;
+	}
+#endif
+	if (!(__raw_readl(S5P_VA_L2CC + L2X0_CTRL) & 0x1)) {
+		l2x0_saved_regs.phy_base = EXYNOS4_PA_L2CC;
+		/* TAG, Data Latency Control: 2 cycles */
+		l2x0_saved_regs.tag_latency = 0x110;
 
-	if (soc_is_exynos4210())
-		__raw_writel(0x110, S5P_VA_L2CC + L2X0_DATA_LATENCY_CTRL);
-	else if (soc_is_exynos4212() || soc_is_exynos4412())
-		__raw_writel(0x120, S5P_VA_L2CC + L2X0_DATA_LATENCY_CTRL);
+		if (soc_is_exynos4212() || soc_is_exynos4412())
+			l2x0_saved_regs.data_latency = 0x120;
+		else
+			l2x0_saved_regs.data_latency = 0x110;
 
-	/* L2X0 Prefetch Control */
-	__raw_writel(0x30000007, S5P_VA_L2CC + L2X0_PREFETCH_CTRL);
+		l2x0_saved_regs.prefetch_ctrl = 0x30000007;
+		l2x0_saved_regs.pwr_ctrl =
+			(L2X0_DYNAMIC_CLK_GATING_EN | L2X0_STNDBY_MODE_EN);
 
-	/* L2X0 Power Control */
-	__raw_writel(L2X0_DYNAMIC_CLK_GATING_EN | L2X0_STNDBY_MODE_EN,
-		     S5P_VA_L2CC + L2X0_POWER_CTRL);
+		l2x0_regs_phys = virt_to_phys(&l2x0_saved_regs);
+
+		__raw_writel(l2x0_saved_regs.tag_latency,
+				S5P_VA_L2CC + L2X0_TAG_LATENCY_CTRL);
+		__raw_writel(l2x0_saved_regs.data_latency,
+				S5P_VA_L2CC + L2X0_DATA_LATENCY_CTRL);
+
+		/* L2X0 Prefetch Control */
+		__raw_writel(l2x0_saved_regs.prefetch_ctrl,
+				S5P_VA_L2CC + L2X0_PREFETCH_CTRL);
+
+		/* L2X0 Power Control */
+		__raw_writel(l2x0_saved_regs.pwr_ctrl,
+				S5P_VA_L2CC + L2X0_POWER_CTRL);
+
+		clean_dcache_area(&l2x0_regs_phys, sizeof(unsigned long));
+		clean_dcache_area(&l2x0_saved_regs, sizeof(struct l2x0_regs));
+	}
 
-	l2x0_init(S5P_VA_L2CC, 0x7C470001, 0xC200ffff);
+	l2x0_init(S5P_VA_L2CC, L2_AUX_VAL, L2_AUX_MASK);
 
 	return 0;
 }
diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c
index 4ebb382c597..1f882aff46b 100644
--- a/arch/arm/mach-exynos/cpuidle.c
+++ b/arch/arm/mach-exynos/cpuidle.c
@@ -11,15 +11,36 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
 #include <linux/io.h>
 #include <linux/export.h>
 #include <linux/time.h>
 
 #include <asm/proc-fns.h>
+#include <asm/smp_scu.h>
+#include <asm/suspend.h>
+#include <asm/unified.h>
+#include <mach/regs-pmu.h>
+#include <mach/pmu.h>
+
+#include <plat/cpu.h>
+
+#define REG_DIRECTGO_ADDR	(samsung_rev() == EXYNOS4210_REV_1_1 ? \
+			S5P_INFORM7 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
+			(S5P_VA_SYSRAM + 0x24) : S5P_INFORM0))
+#define REG_DIRECTGO_FLAG	(samsung_rev() == EXYNOS4210_REV_1_1 ? \
+			S5P_INFORM6 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
+			(S5P_VA_SYSRAM + 0x20) : S5P_INFORM1))
+
+#define S5P_CHECK_AFTR		(samsung_rev() == EXYNOS4210_REV_1_0 ? \
+				0xBAD00000 : 0xFCBA0D10)
 
 static int exynos4_enter_idle(struct cpuidle_device *dev,
 			struct cpuidle_driver *drv,
 			      int index);
+static int exynos4_enter_lowpower(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index);
 
 static struct cpuidle_state exynos4_cpuidle_set[] = {
 	[0] = {
@@ -27,9 +48,17 @@ static struct cpuidle_state exynos4_cpuidle_set[] = {
 		.exit_latency		= 1,
 		.target_residency	= 100000,
 		.flags			= CPUIDLE_FLAG_TIME_VALID,
-		.name			= "IDLE",
+		.name			= "C0",
 		.desc			= "ARM clock gating(WFI)",
 	},
+	[1] = {
+		.enter			= exynos4_enter_lowpower,
+		.exit_latency		= 300,
+		.target_residency	= 100000,
+		.flags			= CPUIDLE_FLAG_TIME_VALID,
+		.name			= "C1",
+		.desc			= "ARM power down",
+	},
 };
 
 static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
@@ -39,9 +68,101 @@ static struct cpuidle_driver exynos4_idle_driver = {
 	.owner		= THIS_MODULE,
 };
 
+/* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */
+static void exynos4_set_wakeupmask(void)
+{
+	__raw_writel(0x0000ff3e, S5P_WAKEUP_MASK);
+}
+
+static unsigned int g_pwr_ctrl, g_diag_reg;
+
+static void save_cpu_arch_register(void)
+{
+	/*read power control register*/
+	asm("mrc p15, 0, %0, c15, c0, 0" : "=r"(g_pwr_ctrl) : : "cc");
+	/*read diagnostic register*/
+	asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc");
+	return;
+}
+
+static void restore_cpu_arch_register(void)
+{
+	/*write power control register*/
+	asm("mcr p15, 0, %0, c15, c0, 0" : : "r"(g_pwr_ctrl) : "cc");
+	/*write diagnostic register*/
+	asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc");
+	return;
+}
+
+static int idle_finisher(unsigned long flags)
+{
+	cpu_do_idle();
+	return 1;
+}
+
+static int exynos4_enter_core0_aftr(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	struct timeval before, after;
+	int idle_time;
+	unsigned long tmp;
+
+	local_irq_disable();
+	do_gettimeofday(&before);
+
+	exynos4_set_wakeupmask();
+
+	/* Set value of power down register for aftr mode */
+	exynos4_sys_powerdown_conf(SYS_AFTR);
+
+	__raw_writel(BSYM(virt_to_phys(s3c_cpu_resume)),
+						 REG_DIRECTGO_ADDR);
+	__raw_writel(S5P_CHECK_AFTR, REG_DIRECTGO_FLAG);
+
+	save_cpu_arch_register();
+
+	/* Setting Central Sequence Register for power down mode */
+	tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
+	tmp &= ~S5P_CENTRAL_LOWPWR_CFG;
+	__raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
+
+	cpu_pm_enter();
+	cpu_suspend(0, idle_finisher);
+
+	scu_enable(S5P_VA_SCU);
+	cpu_pm_exit();
+
+	restore_cpu_arch_register();
+
+	/*
+	 * If PMU failed while entering sleep mode, WFI will be
+	 * ignored by PMU and then exiting cpu_do_idle().
+	 * S5P_CENTRAL_LOWPWR_CFG bit will not be set automatically
+	 * in this situation.
+	 */
+	tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
+	if (!(tmp & S5P_CENTRAL_LOWPWR_CFG)) {
+		tmp |= S5P_CENTRAL_LOWPWR_CFG;
+		__raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
+	}
+
+	/* Clear wakeup state register */
+	__raw_writel(0x0, S5P_WAKEUP_STAT);
+
+	do_gettimeofday(&after);
+
+	local_irq_enable();
+	idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
+		    (after.tv_usec - before.tv_usec);
+
+	dev->last_residency = idle_time;
+	return index;
+}
+
 static int exynos4_enter_idle(struct cpuidle_device *dev,
 				struct cpuidle_driver *drv,
-			      int index)
+				int index)
 {
 	struct timeval before, after;
 	int idle_time;
@@ -60,6 +181,22 @@ static int exynos4_enter_idle(struct cpuidle_device *dev,
 	return index;
 }
 
+static int exynos4_enter_lowpower(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	int new_index = index;
+
+	/* This mode only can be entered when other core's are offline */
+	if (num_online_cpus() > 1)
+		new_index = drv->safe_state_index;
+
+	if (new_index == 0)
+		return exynos4_enter_idle(dev, drv, new_index);
+	else
+		return exynos4_enter_core0_aftr(dev, drv, new_index);
+}
+
 static int __init exynos4_init_cpuidle(void)
 {
 	int i, max_cpuidle_state, cpu_id;
@@ -74,19 +211,25 @@ static int __init exynos4_init_cpuidle(void)
 		memcpy(&drv->states[i], &exynos4_cpuidle_set[i],
 				sizeof(struct cpuidle_state));
 	}
+	drv->safe_state_index = 0;
 	cpuidle_register_driver(&exynos4_idle_driver);
 
 	for_each_cpu(cpu_id, cpu_online_mask) {
 		device = &per_cpu(exynos4_cpuidle_device, cpu_id);
 		device->cpu = cpu_id;
 
-		device->state_count = drv->state_count;
+		if (cpu_id == 0)
+			device->state_count = (sizeof(exynos4_cpuidle_set) /
+					       sizeof(struct cpuidle_state));
+		else
+			device->state_count = 1;	/* Support IDLE only */
 
 		if (cpuidle_register_device(device)) {
 			printk(KERN_ERR "CPUidle register device failed\n,");
 			return -EIO;
 		}
 	}
+
 	return 0;
 }
 device_initcall(exynos4_init_cpuidle);
diff --git a/arch/arm/mach-exynos/include/mach/pmu.h b/arch/arm/mach-exynos/include/mach/pmu.h
index 632dd563013..e76b7faba66 100644
--- a/arch/arm/mach-exynos/include/mach/pmu.h
+++ b/arch/arm/mach-exynos/include/mach/pmu.h
@@ -22,11 +22,13 @@ enum sys_powerdown {
 	NUM_SYS_POWERDOWN,
 };
 
+extern unsigned long l2x0_regs_phys;
 struct exynos4_pmu_conf {
 	void __iomem *reg;
 	unsigned int val[NUM_SYS_POWERDOWN];
 };
 
 extern void exynos4_sys_powerdown_conf(enum sys_powerdown mode);
+extern void s3c_cpu_resume(void);
 
 #endif /* __ASM_ARCH_PMU_H */
diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
index 509a435afd4..0c264e1a234 100644
--- a/arch/arm/mach-exynos/pm.c
+++ b/arch/arm/mach-exynos/pm.c
@@ -154,13 +154,6 @@ static struct sleep_save exynos4_core_save[] = {
 	SAVE_ITEM(S5P_SROM_BC3),
 };
 
-static struct sleep_save exynos4_l2cc_save[] = {
-	SAVE_ITEM(S5P_VA_L2CC + L2X0_TAG_LATENCY_CTRL),
-	SAVE_ITEM(S5P_VA_L2CC + L2X0_DATA_LATENCY_CTRL),
-	SAVE_ITEM(S5P_VA_L2CC + L2X0_PREFETCH_CTRL),
-	SAVE_ITEM(S5P_VA_L2CC + L2X0_POWER_CTRL),
-	SAVE_ITEM(S5P_VA_L2CC + L2X0_AUX_CTRL),
-};
 
 /* For Cortex-A9 Diagnostic and Power control register */
 static unsigned int save_arm_register[2];
@@ -181,7 +174,6 @@ static void exynos4_pm_prepare(void)
 	u32 tmp;
 
 	s3c_pm_do_save(exynos4_core_save, ARRAY_SIZE(exynos4_core_save));
-	s3c_pm_do_save(exynos4_l2cc_save, ARRAY_SIZE(exynos4_l2cc_save));
 	s3c_pm_do_save(exynos4_epll_save, ARRAY_SIZE(exynos4_epll_save));
 	s3c_pm_do_save(exynos4_vpll_save, ARRAY_SIZE(exynos4_vpll_save));
 
@@ -404,13 +396,6 @@ static void exynos4_pm_resume(void)
 
 	exynos4_scu_enable(S5P_VA_SCU);
 
-#ifdef CONFIG_CACHE_L2X0
-	s3c_pm_do_restore_core(exynos4_l2cc_save, ARRAY_SIZE(exynos4_l2cc_save));
-	outer_inv_all();
-	/* enable L2X0*/
-	writel_relaxed(1, S5P_VA_L2CC + L2X0_CTRL);
-#endif
-
 early_wakeup:
 	return;
 }
diff --git a/arch/arm/plat-s5p/sleep.S b/arch/arm/plat-s5p/sleep.S
index 0fd591bfc9f..006bd01eda0 100644
--- a/arch/arm/plat-s5p/sleep.S
+++ b/arch/arm/plat-s5p/sleep.S
@@ -23,9 +23,18 @@
 */
 
 #include <linux/linkage.h>
-#include <asm/assembler.h>
+#include <asm/asm-offsets.h>
+#include <asm/hardware/cache-l2x0.h>
 
-	.text
+/*
+ *	 The following code is located into the .data section. This is to
+ *	 allow l2x0_regs_phys to be accessed with a relative load while we
+ *	 can't rely on any MMU translation. We could have put l2x0_regs_phys
+ *	 in the .text section as well, but some setups might insist on it to
+ *	 be truly read-only. (Reference from: arch/arm/kernel/sleep.S)
+ */
+	.data
+	.align
 
 	/*
 	 * sleep magic, to allow the bootloader to check for an valid
@@ -39,11 +48,34 @@
 	 * s3c_cpu_resume
 	 *
 	 * resume code entry for bootloader to call
-	 *
-	 * we must put this code here in the data segment as we have no
-	 * other way of restoring the stack pointer after sleep, and we
-	 * must not write to the code segment (code is read-only)
 	 */
 
 ENTRY(s3c_cpu_resume)
+#ifdef CONFIG_CACHE_L2X0
+	adr	r0, l2x0_regs_phys
+	ldr	r0, [r0]
+	ldr	r1, [r0, #L2X0_R_PHY_BASE]
+	ldr	r2, [r1, #L2X0_CTRL]
+	tst	r2, #0x1
+	bne	resume_l2on
+	ldr	r2, [r0, #L2X0_R_AUX_CTRL]
+	str	r2, [r1, #L2X0_AUX_CTRL]
+	ldr	r2, [r0, #L2X0_R_TAG_LATENCY]
+	str	r2, [r1, #L2X0_TAG_LATENCY_CTRL]
+	ldr	r2, [r0, #L2X0_R_DATA_LATENCY]
+	str	r2, [r1, #L2X0_DATA_LATENCY_CTRL]
+	ldr	r2, [r0, #L2X0_R_PREFETCH_CTRL]
+	str	r2, [r1, #L2X0_PREFETCH_CTRL]
+	ldr	r2, [r0, #L2X0_R_PWR_CTRL]
+	str	r2, [r1, #L2X0_POWER_CTRL]
+	mov	r2, #1
+	str	r2, [r1, #L2X0_CTRL]
+resume_l2on:
+#endif
 	b	cpu_resume
+ENDPROC(s3c_cpu_resume)
+#ifdef CONFIG_CACHE_L2X0
+	.globl l2x0_regs_phys
+l2x0_regs_phys:
+	.long	0
+#endif