ARM: imx: Add common imx cpuidle init functionality.

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

Signed-off-by: Robert Lee <rob.lee@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

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

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/cpuidle.h>
+#include <linux/err.h>
+#include <linux/hrtimer.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+static struct cpuidle_device __percpu * imx_cpuidle_devices;
+
+static void __init 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);
+}
+
+int __init imx_cpuidle_init(struct cpuidle_driver *drv)
+{
+	struct cpuidle_device *dev;
+	int cpu_id, ret;
+
+	if (drv->state_count > CPUIDLE_STATE_MAX) {
+		pr_err("%s: state_count exceeds maximum\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, error: %d\n",
+				__func__, cpu_id, ret);
+			goto uninit;
+		}
+	}
+
+	return 0;
+
+uninit:
+	imx_cpuidle_devices_uninit();
+
+unregister_drv:
+	cpuidle_unregister_driver(drv);
+	return ret;
+}

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 int imx_cpuidle_init(struct cpuidle_driver *drv);
+#else
+static inline int imx_cpuidle_init(struct cpuidle_driver *drv)
+{
+	return -ENODEV;
+}
+#endif