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powerpc/fsl: add MPIC timer wakeup support
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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>
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Dongsheng.wang@freescale.com authored and Scott Wood committed Jul 1, 2013
1 parent 9e6f31a commit a63b3bc
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9 changes: 9 additions & 0 deletions arch/powerpc/platforms/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -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
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1 change: 1 addition & 0 deletions arch/powerpc/sysdev/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -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
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161 changes: 161 additions & 0 deletions arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c
Original file line number Diff line number Diff line change
@@ -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>");

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