powerpc/fsl: add MPIC timer wakeup support

The driver provides a way to wake up the system by the MPIC timer.

For example,
echo 5 > /sys/devices/system/mpic/timer_wakeup
echo standby > /sys/power/state

After 5 seconds the MPIC timer will generate an interrupt to wake up
the system.

Signed-off-by: Wang Dongsheng <dongsheng.wang@freescale.com>
Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>

diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 7d07d9e..0847ee6 100644 (file)
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -98,6 +98,15 @@ config MPIC_TIMER
          chip, but it can potentially support other global timers
          complying with the OpenPIC standard.
 
+config FSL_MPIC_TIMER_WAKEUP
+       tristate "Freescale MPIC global timer wakeup driver"
+       depends on FSL_SOC &&  MPIC_TIMER && PM
+       default n
+       help
+         The driver provides a way to wake up the system by MPIC
+         timer.
+         e.g. "echo 5 > /sys/devices/system/mpic/timer_wakeup"
+
 config PPC_EPAPR_HV_PIC
        bool
        default n

diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index 2eb72c1..f67ac90 100644 (file)
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -5,6 +5,7 @@ ccflags-$(CONFIG_PPC64)         := $(NO_MINIMAL_TOC)
 mpic-msi-obj-$(CONFIG_PCI_MSI) += mpic_msi.o mpic_u3msi.o mpic_pasemi_msi.o
 obj-$(CONFIG_MPIC)             += mpic.o $(mpic-msi-obj-y)
 obj-$(CONFIG_MPIC_TIMER)        += mpic_timer.o
+obj-$(CONFIG_FSL_MPIC_TIMER_WAKEUP)    += fsl_mpic_timer_wakeup.o
 mpic-msgr-obj-$(CONFIG_MPIC_MSGR)      += mpic_msgr.o
 obj-$(CONFIG_MPIC)             += mpic.o $(mpic-msi-obj-y) $(mpic-msgr-obj-y)
 obj-$(CONFIG_PPC_EPAPR_HV_PIC) += ehv_pic.o

diff --git a/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c b/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c
new file mode 100644 (file)
index 0000000..1707bf0
--- /dev/null
+++ b/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c
@@ -0,0 +1,161 @@
+/*
+ * MPIC timer wakeup driver
+ *
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+
+#include <asm/mpic_timer.h>
+#include <asm/mpic.h>
+
+struct fsl_mpic_timer_wakeup {
+       struct mpic_timer *timer;
+       struct work_struct free_work;
+};
+
+static struct fsl_mpic_timer_wakeup *fsl_wakeup;
+static DEFINE_MUTEX(sysfs_lock);
+
+static void fsl_free_resource(struct work_struct *ws)
+{
+       struct fsl_mpic_timer_wakeup *wakeup =
+               container_of(ws, struct fsl_mpic_timer_wakeup, free_work);
+
+       mutex_lock(&sysfs_lock);
+
+       if (wakeup->timer) {
+               disable_irq_wake(wakeup->timer->irq);
+               mpic_free_timer(wakeup->timer);
+       }
+
+       wakeup->timer = NULL;
+       mutex_unlock(&sysfs_lock);
+}
+
+static irqreturn_t fsl_mpic_timer_irq(int irq, void *dev_id)
+{
+       struct fsl_mpic_timer_wakeup *wakeup = dev_id;
+
+       schedule_work(&wakeup->free_work);
+
+       return wakeup->timer ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static ssize_t fsl_timer_wakeup_show(struct device *dev,
+                               struct device_attribute *attr,
+                               char *buf)
+{
+       struct timeval interval;
+       int val = 0;
+
+       mutex_lock(&sysfs_lock);
+       if (fsl_wakeup->timer) {
+               mpic_get_remain_time(fsl_wakeup->timer, &interval);
+               val = interval.tv_sec + 1;
+       }
+       mutex_unlock(&sysfs_lock);
+
+       return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t fsl_timer_wakeup_store(struct device *dev,
+                               struct device_attribute *attr,
+                               const char *buf,
+                               size_t count)
+{
+       struct timeval interval;
+       int ret;
+
+       interval.tv_usec = 0;
+       if (kstrtol(buf, 0, &interval.tv_sec))
+               return -EINVAL;
+
+       mutex_lock(&sysfs_lock);
+
+       if (fsl_wakeup->timer) {
+               disable_irq_wake(fsl_wakeup->timer->irq);
+               mpic_free_timer(fsl_wakeup->timer);
+               fsl_wakeup->timer = NULL;
+       }
+
+       if (!interval.tv_sec) {
+               mutex_unlock(&sysfs_lock);
+               return count;
+       }
+
+       fsl_wakeup->timer = mpic_request_timer(fsl_mpic_timer_irq,
+                                               fsl_wakeup, &interval);
+       if (!fsl_wakeup->timer) {
+               mutex_unlock(&sysfs_lock);
+               return -EINVAL;
+       }
+
+       ret = enable_irq_wake(fsl_wakeup->timer->irq);
+       if (ret) {
+               mpic_free_timer(fsl_wakeup->timer);
+               fsl_wakeup->timer = NULL;
+               mutex_unlock(&sysfs_lock);
+
+               return ret;
+       }
+
+       mpic_start_timer(fsl_wakeup->timer);
+
+       mutex_unlock(&sysfs_lock);
+
+       return count;
+}
+
+static struct device_attribute mpic_attributes = __ATTR(timer_wakeup, 0644,
+                       fsl_timer_wakeup_show, fsl_timer_wakeup_store);
+
+static int __init fsl_wakeup_sys_init(void)
+{
+       int ret;
+
+       fsl_wakeup = kzalloc(sizeof(struct fsl_mpic_timer_wakeup), GFP_KERNEL);
+       if (!fsl_wakeup)
+               return -ENOMEM;
+
+       INIT_WORK(&fsl_wakeup->free_work, fsl_free_resource);
+
+       ret = device_create_file(mpic_subsys.dev_root, &mpic_attributes);
+       if (ret)
+               kfree(fsl_wakeup);
+
+       return ret;
+}
+
+static void __exit fsl_wakeup_sys_exit(void)
+{
+       device_remove_file(mpic_subsys.dev_root, &mpic_attributes);
+
+       mutex_lock(&sysfs_lock);
+
+       if (fsl_wakeup->timer) {
+               disable_irq_wake(fsl_wakeup->timer->irq);
+               mpic_free_timer(fsl_wakeup->timer);
+       }
+
+       kfree(fsl_wakeup);
+
+       mutex_unlock(&sysfs_lock);
+}
+
+module_init(fsl_wakeup_sys_init);
+module_exit(fsl_wakeup_sys_exit);
+
+MODULE_DESCRIPTION("Freescale MPIC global timer wakeup driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wang Dongsheng <dongsheng.wang@freescale.com>");