[PATCH v2 15/19] OMAP4: cpuidle: Basic CPUidle support
Santosh Shilimkar
santosh.shilimkar at ti.com
Thu Mar 10 09:08:11 EST 2011
From: Rajendra Nayak <rnayak at ti.com>
The patch adds a basic CPUidle driver for OMAP4. Just
one C state is registered for CPU0 which does a WFI.
CPU1 is left with defualt idle and the low power state
for it is managed via cpu-hotplug.
Signed-off-by: Rajendra Nayak <rnayak at ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
Cc: Kevin Hilman <khilman at ti.com>
---
arch/arm/mach-omap2/Makefile | 3 +-
arch/arm/mach-omap2/cpuidle44xx.c | 161 +++++++++++++++++++++++++++++++++++++
arch/arm/mach-omap2/pm.h | 1 +
arch/arm/mach-omap2/pm44xx.c | 2 +
4 files changed, 166 insertions(+), 1 deletions(-)
create mode 100644 arch/arm/mach-omap2/cpuidle44xx.c
diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 04b97bb..c003435 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -64,7 +64,8 @@ obj-$(CONFIG_ARCH_OMAP2) += sleep24xx.o pm_bus.o
obj-$(CONFIG_ARCH_OMAP3) += pm34xx.o sleep34xx.o \
cpuidle34xx.o pm_bus.o
obj-$(CONFIG_ARCH_OMAP4) += pm44xx.o pm_bus.o \
- omap4-mpuss-lowpower.o sleep44xx.o
+ omap4-mpuss-lowpower.o sleep44xx.o \
+ cpuidle44xx.o
obj-$(CONFIG_PM_DEBUG) += pm-debug.o
obj-$(CONFIG_OMAP_SMARTREFLEX) += sr_device.o smartreflex.o
obj-$(CONFIG_OMAP_SMARTREFLEX_CLASS3) += smartreflex-class3.o
diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c
new file mode 100644
index 0000000..270404f
--- /dev/null
+++ b/arch/arm/mach-omap2/cpuidle44xx.c
@@ -0,0 +1,161 @@
+/*
+ * OMAP4 CPU idle Routines
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Rajendra Nayak <rnayak at ti.com>
+ *
+ * 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/sched.h>
+#include <linux/cpuidle.h>
+
+#include <asm/proc-fns.h>
+
+#include <mach/omap4-common.h>
+
+#include "pm.h"
+
+#ifdef CONFIG_CPU_IDLE
+
+#define OMAP4_MAX_STATES 1
+/* C1 - CPU0 ON + + CPU1 ON + MPU ON + CORE ON */
+#define OMAP4_STATE_C1 0
+
+struct omap4_processor_cx {
+ u8 valid;
+ u8 type;
+ u32 sleep_latency;
+ u32 wakeup_latency;
+ u32 cpu0_state;
+ u32 mpu_state;
+ u32 core_state;
+ u32 threshold;
+ u32 flags;
+};
+
+struct omap4_processor_cx omap4_power_states[OMAP4_MAX_STATES];
+
+static struct cpuidle_params cpuidle_params_table[] = {
+ /* C1 */
+ {1, 2, 2, 5},
+};
+
+/**
+ * omap4_enter_idle - Programs OMAP4 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 low power state selected by the governor.
+ * Returns the amount of time spent in the low power state.
+ */
+static int omap4_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_state *state)
+{
+ struct timespec ts_preidle, ts_postidle, ts_idle;
+
+ /* Used to keep track of the total time in idle */
+ getnstimeofday(&ts_preidle);
+
+ local_irq_disable();
+ local_fiq_disable();
+
+ cpu_do_idle();
+
+ getnstimeofday(&ts_postidle);
+ ts_idle = timespec_sub(ts_postidle, ts_preidle);
+
+ local_irq_enable();
+ local_fiq_enable();
+
+ return ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * USEC_PER_SEC;
+}
+
+DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);
+
+/**
+ * omap4_init_power_states - Initialises the OMAP4 specific C states.
+ *
+ * Below is the desciption of each C state.
+ * C1 : CPUx wfi + MPU inative + Core inactive
+ */
+void omap4_init_power_states(void)
+{
+ /*
+ * C1 - CPU0 ON + + CPU1 ON + MPU ON + CORE ON
+ */
+ omap4_power_states[OMAP4_STATE_C1].valid =
+ cpuidle_params_table[OMAP4_STATE_C1].valid;
+ omap4_power_states[OMAP4_STATE_C1].type = OMAP4_STATE_C1;
+ omap4_power_states[OMAP4_STATE_C1].sleep_latency =
+ cpuidle_params_table[OMAP4_STATE_C1].sleep_latency;
+ omap4_power_states[OMAP4_STATE_C1].wakeup_latency =
+ cpuidle_params_table[OMAP4_STATE_C1].wake_latency;
+ omap4_power_states[OMAP4_STATE_C1].threshold =
+ cpuidle_params_table[OMAP4_STATE_C1].threshold;
+ omap4_power_states[OMAP4_STATE_C1].mpu_state = PWRDM_POWER_ON;
+ omap4_power_states[OMAP4_STATE_C1].core_state = PWRDM_POWER_ON;
+ omap4_power_states[OMAP4_STATE_C1].flags = CPUIDLE_FLAG_TIME_VALID;
+
+}
+
+struct cpuidle_driver omap4_idle_driver = {
+ .name = "omap4_idle",
+ .owner = THIS_MODULE,
+};
+
+/**
+ * omap4_idle_init - Init routine for OMAP4 idle
+ *
+ * Registers the OMAP4 specific cpuidle driver with the cpuidle
+ * framework with the valid set of states.
+ */
+int __init omap4_idle_init(void)
+{
+ int cpu_id = 0, i, count = 0;
+ struct omap4_processor_cx *cx;
+ struct cpuidle_state *state;
+ struct cpuidle_device *dev;
+
+ omap4_init_power_states();
+ cpuidle_register_driver(&omap4_idle_driver);
+
+ dev = &per_cpu(omap4_idle_dev, cpu_id);
+ dev->cpu = cpu_id;
+ count = 0;
+ for (i = OMAP4_STATE_C1; i < OMAP4_MAX_STATES; i++) {
+ cx = &omap4_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 = omap4_enter_idle;
+ sprintf(state->name, "C%d", count+1);
+ count++;
+ }
+
+ if (!count)
+ return -EINVAL;
+ dev->state_count = count;
+
+ if (cpuidle_register_device(dev)) {
+ pr_err("%s: CPUidle register device failed\n", __func__);
+ return -EIO;
+ }
+
+ return 0;
+}
+#else
+int __init omap4_idle_init(void)
+{
+ return 0;
+}
+#endif /* CONFIG_CPU_IDLE */
diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index ec5a36f..36cc2cf 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -22,6 +22,7 @@ extern void omap_sram_idle(void);
extern int omap3_can_sleep(void);
extern int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 state);
extern int omap3_idle_init(void);
+extern int omap4_idle_init(void);
#if defined(CONFIG_PM_OPP)
extern int omap3_opp_init(void);
diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c
index 14d4229..d4ad31e 100644
--- a/arch/arm/mach-omap2/pm44xx.c
+++ b/arch/arm/mach-omap2/pm44xx.c
@@ -224,6 +224,8 @@ static int __init omap4_pm_init(void)
suspend_set_ops(&omap_pm_ops);
#endif /* CONFIG_SUSPEND */
+ omap4_idle_init();
+
err2:
return ret;
}
--
1.6.0.4
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