[RFC PATCH] powerpc/fsl: add timer wakeup source

[Wang Dongsheng]

This is only for freescale powerpc platform. The driver provides a way
to wake up system. Proc interface(/proc/powerpc/wakeup_timer_seconds).

eg: "echo 5 > /proc/powerpc/wakeup_timer_seconds", 5 seconds
after the system will be woken up. echo another time into proc interface
to update the time.

Signed-off-by: Wang Dongsheng <dongsheng.wang at freescale.com>
Signed-off-by: Li Yang <leoli at freescale.com>
---
 arch/powerpc/platforms/Kconfig            |   23 +++
 arch/powerpc/platforms/Makefile           |    1 +
 arch/powerpc/platforms/fsl_timer_wakeup.c |  217 +++++++++++++++++++++++++++++
 3 files changed, 241 insertions(+)
 create mode 100644 arch/powerpc/platforms/fsl_timer_wakeup.c

diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index b190a6e..7b9232a 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -99,6 +99,29 @@ config MPIC_TIMER
 	  only tested on fsl chip, but it can potentially support
 	  other global timers complying to Open-PIC standard.
 
+menuconfig FSL_WAKEUP_SOURCE
+	bool "Freescale wakeup source"
+	depends on FSL_SOC && SUSPEND
+	default n
+	help
+	  This option enables wakeup source for wake up system
+	  features. This is only for freescale powerpc platform.
+
+if FSL_WAKEUP_SOURCE
+
+config FSL_TIMER_WAKEUP
+	tristate "Freescale mpic global timer wakeup event"
+	default n
+	help
+	  This is only for freescale powerpc platform. The driver
+	  provides a way to wake up system.
+	  Proc interface(/proc/powerpc/wakeup_timer_seconds).
+	  eg: "echo 5 > /proc/powerpc/wakeup_timer_seconds",
+	  5 seconds after the system will be woken up. echo another
+	  time into proc interface to update the time.
+
+endif
+
 config PPC_EPAPR_HV_PIC
 	bool
 	default n
diff --git a/arch/powerpc/platforms/Makefile b/arch/powerpc/platforms/Makefile
index 879b4a4..8e9a04f 100644
--- a/arch/powerpc/platforms/Makefile
+++ b/arch/powerpc/platforms/Makefile
@@ -2,6 +2,7 @@
 subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
 
 obj-$(CONFIG_FSL_ULI1575)	+= fsl_uli1575.o
+obj-$(CONFIG_FSL_TIMER_WAKEUP)	+= fsl_timer_wakeup.o
 
 obj-$(CONFIG_PPC_PMAC)		+= powermac/
 obj-$(CONFIG_PPC_CHRP)		+= chrp/
diff --git a/arch/powerpc/platforms/fsl_timer_wakeup.c b/arch/powerpc/platforms/fsl_timer_wakeup.c
new file mode 100644
index 0000000..f20199f
--- /dev/null
+++ b/arch/powerpc/platforms/fsl_timer_wakeup.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Wang Dongsheng <Dongsheng.Wang at freescale.com>
+ * Li Yang <leoli at freescale.com>
+ *
+ * This is only for freescale powerpc platform. The driver provides a way
+ * to wake up system. Proc interface(/proc/powerpc/wakeup_timer_seconds).
+ *
+ * eg: "echo 5 > /proc/powerpc/wakeup_timer_seconds", 5 seconds
+ * after the system will be woken up. echo another time into proc interface
+ * to update the time.
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/proc_fs.h>
+#include <asm/uaccess.h>
+#include <asm/mpic_timer.h>
+
+struct fsl_timer_wakeup {
+	struct mpic_timer *timer;
+	struct work_struct free_work;
+	struct mutex mutex;
+	struct proc_dir_entry *proc_timer_wakeup;
+	struct timeval time;
+};
+
+static struct fsl_timer_wakeup *priv;
+
+static void timer_event_wakeup_free_work(struct work_struct *ws)
+{
+	struct fsl_timer_wakeup *priv =
+		container_of(ws, struct fsl_timer_wakeup, free_work);
+
+	mutex_lock(&priv->mutex);
+	mpic_free_timer(priv->timer);
+	priv->timer = NULL;
+	mutex_unlock(&priv->mutex);
+}
+
+static irqreturn_t timer_event_interrupt(int irq, void *dev_id)
+{
+	struct fsl_timer_wakeup *priv = dev_id;
+
+	schedule_work(&priv->free_work);
+
+	return IRQ_HANDLED;
+}
+
+static ssize_t timer_wakeup_read(struct file *file, char __user *buf,
+		size_t count, loff_t *offp)
+{
+	struct fsl_timer_wakeup *priv;
+	struct inode *inode = file->f_path.dentry->d_inode;
+	struct proc_dir_entry *dp;
+
+	int ret;
+	char *kbuf;
+
+	dp = PDE(inode);
+	priv = dp->data;
+
+	mutex_lock(&priv->mutex);
+
+	if (!priv->timer ||
+			(priv->time.tv_sec >= 0 && priv->time.tv_usec >= 0)) {
+		priv->time.tv_sec = -1;
+		priv->time.tv_usec = -1;
+
+		mutex_unlock(&priv->mutex);
+
+		return 0;
+	}
+
+	mpic_get_remain_time(priv->timer, &priv->time);
+
+	mutex_unlock(&priv->mutex);
+
+	kbuf = kzalloc(count, GFP_KERNEL);
+	if (!kbuf)
+		return -ENOMEM;
+
+	sprintf(kbuf, "%ld\n%c", priv->time.tv_sec + 1, '\0');
+
+	ret = strlen(kbuf);
+
+	copy_to_user(buf, kbuf, count);
+
+	kfree(kbuf);
+
+	return ret;
+}
+
+static ssize_t timer_wakeup_write(struct file *file, const char __user *buf,
+		size_t count, loff_t *off)
+{
+	struct fsl_timer_wakeup *priv;
+	struct inode *inode = file->f_path.dentry->d_inode;
+	struct proc_dir_entry *dp;
+	struct timeval time;
+	char *kbuf;
+
+	dp = PDE(inode);
+	priv = dp->data;
+
+	kbuf = kzalloc(count + 1, GFP_KERNEL);
+	if (!kbuf)
+		return -ENOMEM;
+
+	if (copy_from_user(kbuf, buf, count)) {
+		kfree(kbuf);
+		return -EFAULT;
+	}
+
+	kbuf[count] = '\0';
+
+	if (kstrtol(kbuf, 0, &time.tv_sec)) {
+		kfree(kbuf);
+		return -EINVAL;
+	}
+
+	kfree(kbuf);
+
+	time.tv_usec = 0;
+
+	mutex_lock(&priv->mutex);
+
+	if (!time.tv_sec) {
+		if (priv->timer) {
+			mpic_free_timer(priv->timer);
+			priv->timer = NULL;
+		}
+		mutex_unlock(&priv->mutex);
+
+		return count;
+	}
+
+	if (priv->timer) {
+		mpic_free_timer(priv->timer);
+		priv->timer = NULL;
+	}
+
+	priv->timer = mpic_request_timer(timer_event_interrupt, priv, &time);
+	if (!priv->timer) {
+		mutex_unlock(&priv->mutex);
+
+		return -EINVAL;
+	}
+
+	mpic_start_timer(priv->timer);
+
+	mutex_unlock(&priv->mutex);
+
+	return count;
+}
+
+static const struct file_operations timer_wakeup_fops = {
+	.owner		= THIS_MODULE,
+	.read		= timer_wakeup_read,
+	.write		= timer_wakeup_write,
+	.llseek		= no_llseek,
+};
+
+static int timer_wakeup_init(void)
+{
+	struct proc_dir_entry *ent;
+
+	priv = kzalloc(sizeof(struct fsl_timer_wakeup), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mutex_init(&priv->mutex);
+	INIT_WORK(&priv->free_work, timer_event_wakeup_free_work);
+	priv->time.tv_sec = -1;
+	priv->time.tv_usec = -1;
+
+	ent = proc_create_data("powerpc/wakeup_timer_seconds",
+			S_IRUSR | S_IWUSR, NULL, &timer_wakeup_fops, priv);
+	if (!ent) {
+		kfree(priv);
+		return -ENOMEM;
+	}
+
+	priv->proc_timer_wakeup = ent;
+
+	return 0;
+}
+
+static void timer_wakeup_exit(void)
+{
+	if (priv->timer)
+		mpic_free_timer(priv->timer);
+
+	remove_proc_entry("wakeup_timer_seconds",
+			priv->proc_timer_wakeup->parent);
+
+	kfree(priv);
+}
+
+module_init(timer_wakeup_init);
+module_exit(timer_wakeup_exit);
+
+MODULE_DESCRIPTION("Freescale mpic global timer event wake-up driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wang Dongsheng <dongsheng.wang at freescale.com>");
-- 
1.7.9.5