[PATCH v2 1/3] ARM: imx: Add common imx cpuidle init functionality.

Shawn,

On Tue, May 1, 2012 at 10:13 PM, Shawn Guo [off-list ref] wrote:

On Tue, May 01, 2012 at 09:12:38PM -0500, Robert Lee wrote:

quoted

Add common cpuidle init functionality that can be used by various
imx platforms.

Signed-off-by: Robert Lee <redacted>
---
?arch/arm/plat-mxc/Makefile ? ? ? ? ? ? ? | ? ?1 +
?arch/arm/plat-mxc/cpuidle.c ? ? ? ? ? ? ?| ? 80 ++++++++++++++++++++++++++++++
?arch/arm/plat-mxc/include/mach/cpuidle.h | ? 22 ++++++++
?3 files changed, 103 insertions(+)
?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 e81290c..63b064b 100644
--- a/arch/arm/plat-mxc/Makefile
+++ b/arch/arm/plat-mxc/Makefile

@@ -16,6 +16,7 @@ obj-$(CONFIG_MXC_ULPI) += ulpi.o

?obj-$(CONFIG_MXC_USE_EPIT) += epit.o
?obj-$(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..b7a5e1c
--- /dev/null
+++ b/arch/arm/plat-mxc/cpuidle.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2012 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/hrtimer.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+
+static struct cpuidle_device __percpu * imx_cpuidle_devices;
+
+void imx_cpuidle_devices_uninit(void)
+{
+ ? ? int cpu_id;
+ ? ? struct cpuidle_device *dev;
+
+ ? ? for_each_possible_cpu(cpu_id) {
+ ? ? ? ? ? ? dev = per_cpu_ptr(imx_cpuidle_devices, cpu_id);
+ ? ? ? ? ? ? cpuidle_unregister_device(dev);
+ ? ? }
+
+ ? ? free_percpu(imx_cpuidle_devices);
+}

Does this function need to be exported? ?I haven't seen it being
used anywhere outside this file. ?Also, can it be __init?

Yes to both for now and can be changed back if necessary in the future.

quoted

+
+int __init imx_cpuidle_init(struct cpuidle_driver *drv)
+{
+ ? ? struct cpuidle_device *dev;
+ ? ? int cpu_id, ret;
+
+ ? ? if (!drv || drv->state_count > CPUIDLE_STATE_MAX) {
+ ? ? ? ? ? ? pr_err("%s: Invalid Input\n", __func__);
+ ? ? ? ? ? ? return -EINVAL;
+ ? ? }
+
+ ? ? ret = cpuidle_register_driver(drv);
+ ? ? if (ret) {
+ ? ? ? ? ? ? pr_err("%s: Failed to register cpuidle driver with error: %d\n",
+ ? ? ? ? ? ? ? ? ? ? ?__func__, ret);
+ ? ? ? ? ? ? return ret;
+ ? ? }
+
+ ? ? imx_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+ ? ? if (imx_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(imx_cpuidle_devices, cpu_id);
+ ? ? ? ? ? ? dev->cpu = cpu_id;
+ ? ? ? ? ? ? dev->state_count = drv->state_count;
+
+ ? ? ? ? ? ? ret = cpuidle_register_device(dev);
+ ? ? ? ? ? ? if (ret) {
+ ? ? ? ? ? ? ? ? ? ? pr_err("%s: Failed to register cpu %u\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? __func__, cpu_id);

Nit: print ret (error code) too?

I added the printing of the error code based on Sascha's suggestion in
v1 of this submission.

quoted

+ ? ? ? ? ? ? ? ? ? ? goto uninit;
+ ? ? ? ? ? ? }
+ ? ? }
+
+ ? ? return 0;
+
+uninit:
+ ? ? imx_cpuidle_devices_uninit();
+
+unregister_drv:
+ ? ? cpuidle_unregister_driver(drv);
+ ? ? return ret;
+}

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..8612510
--- /dev/null
+++ b/arch/arm/plat-mxc/include/mach/cpuidle.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2012 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/cpuidle.h>
+
+#ifdef CONFIG_CPU_IDLE
+extern void imx_cpuidle_devices_uninit(void);
+extern int imx_cpuidle_init(struct cpuidle_driver *drv);
+#else
+static inline void imx_cpuidle_devices_uninit(void) {}
+static inline int imx_cpuidle_init(struct cpuidle_driver *drv)
+{ return -ENODEV; }

Nit: if it can not be in the same line with function name, we usually
have it be:

{
? ? ? ?return -ENODEV;
}

Understood.  I was just going by what I have seen used in other places
(like include/linux/cpuidle.h).

Thanks,
Rob

quoted

+#endif
--
1.7.10

--
Regards,
Shawn