[PATCH v3 1/7] cpuidle: Add common init interface and idle functionality
Robert Lee
rob.lee at linaro.org
Mon Jan 23 23:37:28 EST 2012
The patch adds some cpuidle initialization functionality commonly
duplicated by many platforms.
Signed-off-by: Robert Lee <rob.lee at linaro.org>
---
drivers/cpuidle/Makefile | 2 +-
drivers/cpuidle/common.c | 152 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/cpuidle.h | 24 +++++++
3 files changed, 177 insertions(+), 1 deletions(-)
create mode 100644 drivers/cpuidle/common.c
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 5634f88..2928d93 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -2,4 +2,4 @@
# Makefile for cpuidle.
#
-obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
+obj-y += cpuidle.o driver.o governor.o sysfs.o common.o governors/
diff --git a/drivers/cpuidle/common.c b/drivers/cpuidle/common.c
new file mode 100644
index 0000000..dafa758
--- /dev/null
+++ b/drivers/cpuidle/common.c
@@ -0,0 +1,152 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/*
+ * This code performs provides some commonly used cpuidle setup functionality
+ * used by many ARM SoC platforms. Providing this functionality here
+ * reduces the duplication of this code for each ARM platform that uses it.
+ */
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/cpuidle.h>
+#include <linux/hrtimer.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <asm/proc-fns.h>
+
+static struct cpuidle_device __percpu * common_cpuidle_devices;
+
+static int (*do_idle[CPUIDLE_STATE_MAX])(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index);
+
+int cpuidle_def_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ cpu_do_idle();
+ return index;
+}
+
+static int simple_enter(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ ktime_t time_start, time_end;
+
+ local_irq_disable();
+
+ time_start = ktime_get();
+
+ index = do_idle[index](dev, drv, index);
+
+ time_end = ktime_get();
+
+ local_irq_enable();
+
+ dev->last_residency =
+ (int)ktime_to_us(ktime_sub(time_end, time_start));
+
+ return index;
+}
+
+void common_cpuidle_devices_uninit(void)
+{
+ int cpu_id;
+ struct cpuidle_device *dev;
+
+ for_each_possible_cpu(cpu_id) {
+ dev = per_cpu_ptr(common_cpuidle_devices, cpu_id);
+ cpuidle_unregister_device(dev);
+ }
+
+ free_percpu(common_cpuidle_devices);
+}
+
+/**
+ * common_cpuidle_init() - Provides some commonly used init functionality.
+ * @pdrv Pointer to your cpuidle_driver object.
+ * @simple Use the common simple_enter wrapper?
+ * @driver_data_init Pointer to your platform function to initialize your
+ * platform specific driver data. Use NULL if platform
+ * specific data is not needed.
+ *
+ * Common cpuidle init interface to provide common cpuidle functionality
+ * used by many platforms.
+ */
+int __init common_cpuidle_init(struct cpuidle_driver *pdrv, bool simple,
+ void (*driver_data_init)(struct cpuidle_device *dev))
+{
+ struct cpuidle_device *dev;
+ struct cpuidle_driver *drv;
+ int i, cpu_id, ret;
+
+ if (!pdrv || pdrv->state_count > CPUIDLE_STATE_MAX) {
+ pr_err("%s: Invalid Input\n", __func__);
+ return -EINVAL;
+ }
+
+ drv = kmalloc(sizeof(struct cpuidle_driver), GFP_KERNEL);
+ if (!drv) {
+ pr_err("%s: no memory for cpuidle driver\n", __func__);
+ return -ENOMEM;
+ }
+
+ *drv = *pdrv;
+
+ for (i = 0; simple && (i < drv->state_count); i++) {
+ do_idle[i] = drv->states[i].enter;
+ drv->states[i].enter = simple_enter;
+ }
+
+ ret = cpuidle_register_driver(drv);
+ if (ret) {
+ pr_err("%s: Failed to register cpuidle driver\n", __func__);
+ goto free_drv;
+ }
+
+ common_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+ if (common_cpuidle_devices == NULL) {
+ ret = -ENOMEM;
+ goto unregister_drv;
+ }
+
+ /* initialize state data for each cpuidle_device */
+ for_each_possible_cpu(cpu_id) {
+ dev = per_cpu_ptr(common_cpuidle_devices, cpu_id);
+ dev->cpu = cpu_id;
+ dev->state_count = drv->state_count;
+
+ if (driver_data_init)
+ driver_data_init(dev);
+
+ ret = cpuidle_register_device(dev);
+ if (ret) {
+ pr_err("%s: Failed to register cpu %u\n",
+ __func__, cpu_id);
+ goto uninit;
+ }
+ }
+
+ return 0;
+uninit:
+
+ common_cpuidle_devices_uninit();
+
+unregister_drv:
+
+ cpuidle_unregister_driver(drv);
+
+free_drv:
+
+ kfree(drv);
+
+ return ret;
+}
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 712abcc..2aa89db 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -56,6 +56,16 @@ struct cpuidle_state {
#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
+/* Common ARM WFI state */
+#define CPUIDLE_ARM_WFI_STATE {\
+ .enter = cpuidle_def_idle,\
+ .exit_latency = 2,\
+ .target_residency = 1,\
+ .flags = CPUIDLE_FLAG_TIME_VALID,\
+ .name = "WFI",\
+ .desc = "ARM core clock gating (WFI)",\
+}
+
/**
* cpuidle_get_statedata - retrieves private driver state data
* @st_usage: the state usage statistics
@@ -141,6 +151,13 @@ extern void cpuidle_resume_and_unlock(void);
extern int cpuidle_enable_device(struct cpuidle_device *dev);
extern void cpuidle_disable_device(struct cpuidle_device *dev);
+/* provide a default idle function */
+extern int cpuidle_def_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index);
+extern int common_cpuidle_init(struct cpuidle_driver *drv, bool simple,
+ void (*driver_data_init)(struct cpuidle_device *dev));
+extern void common_cpuidle_devices_uninit(void);
+
#else
static inline void disable_cpuidle(void) { }
static inline int cpuidle_idle_call(void) { return -ENODEV; }
@@ -157,6 +174,13 @@ static inline void cpuidle_resume_and_unlock(void) { }
static inline int cpuidle_enable_device(struct cpuidle_device *dev)
{return -ENODEV; }
static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
+static inline int cpuidle_def_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{return -ENODEV; }
+static inline int common_cpuidle_init(struct cpuidle_driver *pdrv,
+ bool simple, void (*driver_data_init)(struct cpuidle_device *dev))
+{return -ENODEV; }
+static inline void common_cpuidle_devices_uninit(void) { }
#endif
--
1.7.1
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