OMAP3: PM: CPUidle: base driver and support for C1-C2

Basic CPUidle driver for OMAP3 with deepest sleep state supported
being MPU CSWR.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

4 files changed, 260 insertions, 2 deletions

diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 8cb16777661a..1d54ad349bfd 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -31,7 +31,7 @@ obj-$(CONFIG_ARCH_OMAP2)		+= sdrc2xxx.o
 ifeq ($(CONFIG_PM),y)
 obj-$(CONFIG_ARCH_OMAP2)		+= pm24xx.o
 obj-$(CONFIG_ARCH_OMAP24XX)		+= sleep24xx.o
-obj-$(CONFIG_ARCH_OMAP3)		+= pm34xx.o sleep34xx.o
+obj-$(CONFIG_ARCH_OMAP3)		+= pm34xx.o sleep34xx.o cpuidle34xx.o
 obj-$(CONFIG_PM_DEBUG)			+= pm-debug.o
 endif
 
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
new file mode 100644
index 000000000000..858b216b63b6
--- /dev/null
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -0,0 +1,255 @@
+/*
+ * linux/arch/arm/mach-omap2/cpuidle34xx.c
+ *
+ * OMAP3 CPU IDLE Routines
+ *
+ * Copyright (C) 2008 Texas Instruments, Inc.
+ * Rajendra Nayak <rnayak@ti.com>
+ *
+ * Copyright (C) 2007 Texas Instruments, Inc.
+ * Karthik Dasu <karthik-dp@ti.com>
+ *
+ * Copyright (C) 2006 Nokia Corporation
+ * Tony Lindgren <tony@atomide.com>
+ *
+ * Copyright (C) 2005 Texas Instruments, Inc.
+ * Richard Woodruff <r-woodruff2@ti.com>
+ *
+ * Based on pm.c for omap2
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/cpuidle.h>
+
+#include <plat/prcm.h>
+#include <plat/powerdomain.h>
+
+#ifdef CONFIG_CPU_IDLE
+
+#define OMAP3_MAX_STATES 7
+#define OMAP3_STATE_C1 1 /* C1 - MPU WFI + Core active */
+#define OMAP3_STATE_C2 2 /* C2 - MPU CSWR + Core active */
+#define OMAP3_STATE_C3 3 /* C3 - MPU OFF + Core active */
+#define OMAP3_STATE_C4 4 /* C4 - MPU RET + Core RET */
+#define OMAP3_STATE_C5 5 /* C5 - MPU OFF + Core RET */
+#define OMAP3_STATE_C6 6 /* C6 - MPU OFF + Core OFF */
+
+struct omap3_processor_cx {
+	u8 valid;
+	u8 type;
+	u32 sleep_latency;
+	u32 wakeup_latency;
+	u32 mpu_state;
+	u32 core_state;
+	u32 threshold;
+	u32 flags;
+};
+
+struct omap3_processor_cx omap3_power_states[OMAP3_MAX_STATES];
+struct omap3_processor_cx current_cx_state;
+struct powerdomain *mpu_pd;
+
+static int omap3_idle_bm_check(void)
+{
+	return 0;
+}
+
+/**
+ * omap3_enter_idle - Programs OMAP3 to enter the specified state
+ * @dev: cpuidle device
+ * @state: The target state to be programmed
+ *
+ * Called from the CPUidle framework to program the device to the
+ * specified target state selected by the governor.
+ */
+static int omap3_enter_idle(struct cpuidle_device *dev,
+			struct cpuidle_state *state)
+{
+	struct omap3_processor_cx *cx = cpuidle_get_statedata(state);
+	struct timespec ts_preidle, ts_postidle, ts_idle;
+
+	current_cx_state = *cx;
+
+	/* Used to keep track of the total time in idle */
+	getnstimeofday(&ts_preidle);
+
+	local_irq_disable();
+	local_fiq_disable();
+
+	/* Program MPU to target state */
+	if (cx->mpu_state < PWRDM_POWER_ON)
+		pwrdm_set_next_pwrst(mpu_pd, cx->mpu_state);
+
+	/* Execute ARM wfi */
+	omap_sram_idle();
+
+	/* Program MPU to ON */
+	if (cx->mpu_state < PWRDM_POWER_ON)
+		pwrdm_set_next_pwrst(mpu_pd, PWRDM_POWER_ON);
+
+	getnstimeofday(&ts_postidle);
+	ts_idle = timespec_sub(ts_postidle, ts_preidle);
+
+	local_irq_enable();
+	local_fiq_enable();
+
+	return timespec_to_ns(&ts_idle);
+}
+
+/**
+ * omap3_enter_idle_bm - Checks for any bus activity
+ * @dev: cpuidle device
+ * @state: The target state to be programmed
+ *
+ * Used for C states with CPUIDLE_FLAG_CHECK_BM flag set. This
+ * function checks for any pending activity and then programs the
+ * device to the specified or a safer state.
+ */
+static int omap3_enter_idle_bm(struct cpuidle_device *dev,
+			       struct cpuidle_state *state)
+{
+	if ((state->flags & CPUIDLE_FLAG_CHECK_BM) && omap3_idle_bm_check()) {
+		if (dev->safe_state)
+			return dev->safe_state->enter(dev, dev->safe_state);
+	}
+	return omap3_enter_idle(dev, state);
+}
+
+DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
+
+/* omap3_init_power_states - Initialises the OMAP3 specific C states.
+ *
+ * Below is the desciption of each C state.
+ *	C1 . MPU WFI + Core active
+ *	C2 . MPU CSWR + Core active
+ *	C3 . MPU OFF + Core active
+ *	C4 . MPU CSWR + Core CSWR
+ *	C5 . MPU OFF + Core CSWR
+ *	C6 . MPU OFF + Core OFF
+ */
+void omap_init_power_states(void)
+{
+	/* C1 . MPU WFI + Core active */
+	omap3_power_states[OMAP3_STATE_C1].valid = 1;
+	omap3_power_states[OMAP3_STATE_C1].type = OMAP3_STATE_C1;
+	omap3_power_states[OMAP3_STATE_C1].sleep_latency = 10;
+	omap3_power_states[OMAP3_STATE_C1].wakeup_latency = 10;
+	omap3_power_states[OMAP3_STATE_C1].threshold = 30;
+	omap3_power_states[OMAP3_STATE_C1].mpu_state = PWRDM_POWER_ON;
+	omap3_power_states[OMAP3_STATE_C1].core_state = PWRDM_POWER_ON;
+	omap3_power_states[OMAP3_STATE_C1].flags = CPUIDLE_FLAG_TIME_VALID;
+
+	/* C2 . MPU CSWR + Core active */
+	omap3_power_states[OMAP3_STATE_C2].valid = 1;
+	omap3_power_states[OMAP3_STATE_C2].type = OMAP3_STATE_C2;
+	omap3_power_states[OMAP3_STATE_C2].sleep_latency = 50;
+	omap3_power_states[OMAP3_STATE_C2].wakeup_latency = 50;
+	omap3_power_states[OMAP3_STATE_C2].threshold = 300;
+	omap3_power_states[OMAP3_STATE_C2].mpu_state = PWRDM_POWER_RET;
+	omap3_power_states[OMAP3_STATE_C2].core_state = PWRDM_POWER_ON;
+	omap3_power_states[OMAP3_STATE_C2].flags = CPUIDLE_FLAG_TIME_VALID;
+
+	/* C3 . MPU OFF + Core active */
+	omap3_power_states[OMAP3_STATE_C3].valid = 0;
+	omap3_power_states[OMAP3_STATE_C3].type = OMAP3_STATE_C3;
+	omap3_power_states[OMAP3_STATE_C3].sleep_latency = 1500;
+	omap3_power_states[OMAP3_STATE_C3].wakeup_latency = 1800;
+	omap3_power_states[OMAP3_STATE_C3].threshold = 4000;
+	omap3_power_states[OMAP3_STATE_C3].mpu_state = PWRDM_POWER_OFF;
+	omap3_power_states[OMAP3_STATE_C3].core_state = PWRDM_POWER_ON;
+	omap3_power_states[OMAP3_STATE_C3].flags = CPUIDLE_FLAG_TIME_VALID;
+
+	/* C4 . MPU CSWR + Core CSWR*/
+	omap3_power_states[OMAP3_STATE_C4].valid = 0;
+	omap3_power_states[OMAP3_STATE_C4].type = OMAP3_STATE_C4;
+	omap3_power_states[OMAP3_STATE_C4].sleep_latency = 2500;
+	omap3_power_states[OMAP3_STATE_C4].wakeup_latency = 7500;
+	omap3_power_states[OMAP3_STATE_C4].threshold = 12000;
+	omap3_power_states[OMAP3_STATE_C4].mpu_state = PWRDM_POWER_RET;
+	omap3_power_states[OMAP3_STATE_C4].core_state = PWRDM_POWER_RET;
+	omap3_power_states[OMAP3_STATE_C4].flags = CPUIDLE_FLAG_TIME_VALID |
+				CPUIDLE_FLAG_CHECK_BM;
+
+	/* C5 . MPU OFF + Core CSWR */
+	omap3_power_states[OMAP3_STATE_C5].valid = 0;
+	omap3_power_states[OMAP3_STATE_C5].type = OMAP3_STATE_C5;
+	omap3_power_states[OMAP3_STATE_C5].sleep_latency = 3000;
+	omap3_power_states[OMAP3_STATE_C5].wakeup_latency = 8500;
+	omap3_power_states[OMAP3_STATE_C5].threshold = 15000;
+	omap3_power_states[OMAP3_STATE_C5].mpu_state = PWRDM_POWER_OFF;
+	omap3_power_states[OMAP3_STATE_C5].core_state = PWRDM_POWER_RET;
+	omap3_power_states[OMAP3_STATE_C5].flags = CPUIDLE_FLAG_TIME_VALID |
+				CPUIDLE_FLAG_CHECK_BM;
+
+	/* C6 . MPU OFF + Core OFF */
+	omap3_power_states[OMAP3_STATE_C6].valid = 0;
+	omap3_power_states[OMAP3_STATE_C6].type = OMAP3_STATE_C6;
+	omap3_power_states[OMAP3_STATE_C6].sleep_latency = 10000;
+	omap3_power_states[OMAP3_STATE_C6].wakeup_latency = 30000;
+	omap3_power_states[OMAP3_STATE_C6].threshold = 300000;
+	omap3_power_states[OMAP3_STATE_C6].mpu_state = PWRDM_POWER_OFF;
+	omap3_power_states[OMAP3_STATE_C6].core_state = PWRDM_POWER_OFF;
+	omap3_power_states[OMAP3_STATE_C6].flags = CPUIDLE_FLAG_TIME_VALID |
+				CPUIDLE_FLAG_CHECK_BM;
+}
+
+struct cpuidle_driver omap3_idle_driver = {
+	.name = 	"omap3_idle",
+	.owner = 	THIS_MODULE,
+};
+
+/**
+ * omap3_idle_init - Init routine for OMAP3 idle
+ *
+ * Registers the OMAP3 specific cpuidle driver with the cpuidle
+ * framework with the valid set of states.
+ */
+int omap3_idle_init(void)
+{
+	int i, count = 0;
+	struct omap3_processor_cx *cx;
+	struct cpuidle_state *state;
+	struct cpuidle_device *dev;
+
+	mpu_pd = pwrdm_lookup("mpu_pwrdm");
+
+	omap_init_power_states();
+	cpuidle_register_driver(&omap3_idle_driver);
+
+	dev = &per_cpu(omap3_idle_dev, smp_processor_id());
+
+	for (i = 1; i < OMAP3_MAX_STATES; i++) {
+		cx = &omap3_power_states[i];
+		state = &dev->states[count];
+
+		if (!cx->valid)
+			continue;
+		cpuidle_set_statedata(state, cx);
+		state->exit_latency = cx->sleep_latency + cx->wakeup_latency;
+		state->target_residency = cx->threshold;
+		state->flags = cx->flags;
+		state->enter = (state->flags & CPUIDLE_FLAG_CHECK_BM) ?
+			omap3_enter_idle_bm : omap3_enter_idle;
+		if (cx->type == OMAP3_STATE_C1)
+			dev->safe_state = state;
+		sprintf(state->name, "C%d", count+1);
+		count++;
+	}
+
+	if (!count)
+		return -EINVAL;
+	dev->state_count = count;
+
+	if (cpuidle_register_device(dev)) {
+		printk(KERN_ERR "%s: CPUidle register device failed\n",
+		       __func__);
+		return -EIO;
+	}
+
+	return 0;
+}
+device_initcall(omap3_idle_init);
+#endif /* CONFIG_CPU_IDLE */
diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index 7eb769f4ef30..2edf1ba12dca 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -18,6 +18,7 @@ extern u32 sleep_while_idle;
 
 extern void *omap3_secure_ram_storage;
 extern void omap3_pm_off_mode_enable(int);
+extern void omap_sram_idle(void);
 
 extern int omap3_pm_get_suspend_state(struct powerdomain *pwrdm);
 extern int omap3_pm_set_suspend_state(struct powerdomain *pwrdm, int state);
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 01b95eaae75a..0c49db8afa99 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -318,7 +318,7 @@ static void restore_table_entry(void)
 	restore_control_register(control_reg_value);
 }
 
-static void omap_sram_idle(void)
+void omap_sram_idle(void)
 {
 	/* Variable to tell what needs to be saved and restored
 	 * in omap_sram_idle*/
@@ -1101,7 +1101,9 @@ static int __init omap3_pm_init(void)
 	suspend_set_ops(&omap_pm_ops);
 #endif /* CONFIG_SUSPEND */
 
+#ifndef CONFIG_CPU_IDLE
 	pm_idle = omap3_pm_idle;
+#endif
 
 	pwrdm_add_wkdep(neon_pwrdm, mpu_pwrdm);
 	/*