[PATCH v2 1/3] ARM: imx: Add imx cpuidle driver
Robert Lee
rob.lee at linaro.org
Fri Sep 16 13:27:48 EDT 2011
Introduce a new cpuidle driver which provides the common cpuidle
functionality necessary for any imx soc cpuidle implementation.
Signed-off-by: Robert Lee <rob.lee at linaro.org>
---
arch/arm/plat-mxc/Makefile | 1 +
arch/arm/plat-mxc/cpuidle.c | 151 ++++++++++++++++++++++++++++++
arch/arm/plat-mxc/include/mach/cpuidle.h | 56 +++++++++++
3 files changed, 208 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/plat-mxc/cpuidle.c
create mode 100644 arch/arm/plat-mxc/include/mach/cpuidle.h
diff --git a/arch/arm/plat-mxc/Makefile b/arch/arm/plat-mxc/Makefile
index d53c35f..8939f79 100644
--- a/arch/arm/plat-mxc/Makefile
+++ b/arch/arm/plat-mxc/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_ARCH_MXC_AUDMUX_V1) += audmux-v1.o
obj-$(CONFIG_ARCH_MXC_AUDMUX_V2) += audmux-v2.o
obj-$(CONFIG_MXC_DEBUG_BOARD) += 3ds_debugboard.o
obj-$(CONFIG_CPU_FREQ_IMX) += cpufreq.o
+obj-$(CONFIG_CPU_IDLE) += cpuidle.o
ifdef CONFIG_SND_IMX_SOC
obj-y += ssi-fiq.o
obj-y += ssi-fiq-ksym.o
diff --git a/arch/arm/plat-mxc/cpuidle.c b/arch/arm/plat-mxc/cpuidle.c
new file mode 100644
index 0000000..9e4c176
--- /dev/null
+++ b/arch/arm/plat-mxc/cpuidle.c
@@ -0,0 +1,151 @@
+/*
+ * 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
+ */
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/cpuidle.h>
+#include <linux/err.h>
+#include <asm/proc-fns.h>
+#include <mach/cpuidle.h>
+
+static int (*mach_cpuidle)(struct cpuidle_device *dev,
+ struct cpuidle_state *state);
+static struct cpuidle_driver *imx_cpuidle_driver;
+static struct __initdata cpuidle_device * device;
+
+static int imx_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_state *state)
+{
+ struct timeval before, after;
+ int idle_time;
+
+ local_irq_disable();
+ local_fiq_disable();
+
+ do_gettimeofday(&before);
+
+ mach_cpuidle(dev, state);
+
+ do_gettimeofday(&after);
+
+ local_fiq_enable();
+ local_irq_enable();
+
+ idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
+ (after.tv_usec - before.tv_usec);
+
+ return idle_time;
+}
+
+static DEFINE_PER_CPU(struct cpuidle_device, imx_cpuidle_device);
+
+int __init imx_cpuidle_init(struct imx_cpuidle_data *cpuidle_data)
+{
+ int i, cpu_id;
+
+ if (cpuidle_data == NULL) {
+ pr_err("%s: cpuidle_data pointer NULL\n", __func__);
+ return -EINVAL;
+ }
+
+ if (cpuidle_data->mach_cpuidle == NULL) {
+ pr_err("%s: idle callback function NULL\n", __func__);
+ return -EINVAL;
+ }
+
+ imx_cpuidle_driver = cpuidle_data->imx_cpuidle_driver;
+
+ mach_cpuidle = cpuidle_data->mach_cpuidle;
+
+ /* register imx_cpuidle driver */
+ if (cpuidle_register_driver(imx_cpuidle_driver)) {
+ pr_err("%s: Failed to register cpuidle driver\n", __func__);
+ return -ENODEV;
+ }
+
+ /* if provided, initialize the mach level cpuidle functionality */
+ if (cpuidle_data->mach_cpuidle_init) {
+ if (cpuidle_data->mach_cpuidle_init(cpuidle_data)) {
+ pr_err("%s: Failed to register cpuidle driver\n",
+ __func__);
+ cpuidle_unregister_driver(imx_cpuidle_driver);
+ return -ENODEV;
+ }
+ }
+
+ /* initialize state data for each cpuidle_device */
+ for_each_cpu(cpu_id, cpu_online_mask) {
+
+ device = &per_cpu(imx_cpuidle_device, cpu_id);
+ device->cpu = cpu_id;
+
+ device->state_count = min((unsigned int) CPUIDLE_STATE_MAX,
+ cpuidle_data->num_states);
+
+ device->prepare = cpuidle_data->prepare;
+
+ for (i = 0; i < device->state_count; i++) {
+ strlcpy(device->states[i].name,
+ cpuidle_data->state_data[i].name,
+ CPUIDLE_NAME_LEN);
+
+ strlcpy(device->states[i].desc,
+ cpuidle_data->state_data[i].desc,
+ CPUIDLE_DESC_LEN);
+
+ device->states[i].driver_data =
+ (void *)cpuidle_data->
+ state_data[i].mach_cpu_pwr_state;
+
+ /*
+ * Because the imx_enter_idle function measures
+ * and returns a valid time for all imx SoCs,
+ * we always set this flag.
+ */
+ device->states[i].flags = CPUIDLE_FLAG_TIME_VALID;
+
+ device->states[i].exit_latency =
+ cpuidle_data->state_data[i].exit_latency;
+
+ device->states[i].power_usage =
+ cpuidle_data->state_data[i].power_usage;
+
+ device->states[i].target_residency =
+ cpuidle_data->state_data[i].target_residency;
+
+ device->states[i].enter = imx_enter_idle;
+ }
+ }
+
+ return 0;
+}
+
+int __init imx_cpuidle_dev_init(void)
+{
+ int cpu_id;
+
+ if (device == NULL) {
+ pr_err("%s: Failed to register (No device)\n", __func__);
+ return -ENODEV;
+ }
+
+ for_each_cpu(cpu_id, cpu_online_mask) {
+ device = &per_cpu(imx_cpuidle_device, cpu_id);
+ if (cpuidle_register_device(device)) {
+ pr_err("%s: Failed to register\n", __func__);
+ return -ENODEV;
+ }
+ }
+
+ return 0;
+}
+late_initcall(imx_cpuidle_dev_init);
diff --git a/arch/arm/plat-mxc/include/mach/cpuidle.h b/arch/arm/plat-mxc/include/mach/cpuidle.h
new file mode 100644
index 0000000..2bb109e
--- /dev/null
+++ b/arch/arm/plat-mxc/include/mach/cpuidle.h
@@ -0,0 +1,56 @@
+/*
+ * 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
+ */
+
+#ifndef __ARCH_ARM_PLAT_MXC_CPUIDLE_H__
+#define __ARCH_ARM_PLAT_MXC_CPUIDLE_H__
+
+#include <linux/cpuidle.h>
+#include <mach/hardware.h>
+
+/* for passing cpuidle state info to the cpuidle driver. */
+struct imx_cpuidle_state_data {
+ enum mxc_cpu_pwr_mode mach_cpu_pwr_state;
+ char *name;
+ char *desc;
+ /* time in uS to exit this idle state */
+ unsigned int exit_latency;
+ /* OPTIONAL - power usage of this idle state in mW */
+ unsigned int power_usage;
+ /* OPTIONAL - in uS. See drivers/cpuidle/governors/menu.c for usage */
+ unsigned int target_residency;
+};
+
+struct imx_cpuidle_data {
+ unsigned int num_states;
+ struct cpuidle_driver *imx_cpuidle_driver;
+ struct imx_cpuidle_state_data *state_data;
+ int (*mach_cpuidle)(struct cpuidle_device *dev,
+ struct cpuidle_state *state);
+
+ /* OPTIONAL - parameter of mach_cpuidle_init func below */
+ void *mach_init_data;
+ /* OPTIONAL - callback for mach level cpuidle initialization */
+ int (*mach_cpuidle_init)(void *mach_init_data);
+ /* OPTIONAL - Search drivers/cpuidle/cpuidle.c for usage */
+ int (*prepare)(struct cpuidle_device *dev);
+};
+
+#ifdef CONFIG_CPU_IDLE
+int imx_cpuidle_init(struct imx_cpuidle_data *cpuidle_data);
+#else
+static inline int imx_cpuidle_init(struct imx_cpuidle_data *cpuidle_data)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_CPU_IDLE */
+
+#endif /* __ARCH_ARM_PLAT_MXC_CPUIDLE_H__ */
--
1.7.1
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