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* arch/sh/kernel/cpu/shmobile/pm_runtime.c
*
* Runtime PM support code for SuperH Mobile
*
* Copyright (C) 2009 Magnus Damm
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <asm/hwblk.h>
static DEFINE_SPINLOCK(hwblk_lock);
static LIST_HEAD(hwblk_idle_list);
static struct work_struct hwblk_work;
extern struct hwblk_info *hwblk_info;
static void platform_pm_runtime_not_idle(struct platform_device *pdev)
{
unsigned long flags;
/* remove device from idle list */
spin_lock_irqsave(&hwblk_lock, flags);
if (test_bit(PDEV_ARCHDATA_FLAG_IDLE, &pdev->archdata.flags)) {
list_del(&pdev->archdata.entry);
__clear_bit(PDEV_ARCHDATA_FLAG_IDLE, &pdev->archdata.flags);
}
spin_unlock_irqrestore(&hwblk_lock, flags);
}
static int __platform_pm_runtime_resume(struct platform_device *pdev)
{
struct device *d = &pdev->dev;
struct pdev_archdata *ad = &pdev->archdata;
int hwblk = ad->hwblk_id;
int ret = -ENOSYS;
dev_dbg(d, "__platform_pm_runtime_resume() [%d]\n", hwblk);
if (d->driver) {
hwblk_enable(hwblk_info, hwblk);
ret = 0;
if (test_bit(PDEV_ARCHDATA_FLAG_SUSP, &ad->flags)) {
if (d->driver->pm && d->driver->pm->runtime_resume)
ret = d->driver->pm->runtime_resume(d);
if (!ret)
clear_bit(PDEV_ARCHDATA_FLAG_SUSP, &ad->flags);
else
hwblk_disable(hwblk_info, hwblk);
}
}
dev_dbg(d, "__platform_pm_runtime_resume() [%d] - returns %d\n",
hwblk, ret);
return ret;
}
static int __platform_pm_runtime_suspend(struct platform_device *pdev)
{
struct device *d = &pdev->dev;
struct pdev_archdata *ad = &pdev->archdata;
int hwblk = ad->hwblk_id;
int ret = -ENOSYS;
dev_dbg(d, "__platform_pm_runtime_suspend() [%d]\n", hwblk);
if (d->driver) {
BUG_ON(!test_bit(PDEV_ARCHDATA_FLAG_IDLE, &ad->flags));
ret = 0;
if (d->driver->pm && d->driver->pm->runtime_suspend) {
hwblk_enable(hwblk_info, hwblk);
ret = d->driver->pm->runtime_suspend(d);
hwblk_disable(hwblk_info, hwblk);
}
if (!ret) {
set_bit(PDEV_ARCHDATA_FLAG_SUSP, &ad->flags);
platform_pm_runtime_not_idle(pdev);
hwblk_cnt_dec(hwblk_info, hwblk, HWBLK_CNT_IDLE);
}
}
dev_dbg(d, "__platform_pm_runtime_suspend() [%d] - returns %d\n",
hwblk, ret);
return ret;
}
static void platform_pm_runtime_work(struct work_struct *work)
{
struct platform_device *pdev;
unsigned long flags;
int ret;
/* go through the idle list and suspend one device at a time */
do {
spin_lock_irqsave(&hwblk_lock, flags);
if (list_empty(&hwblk_idle_list))
pdev = NULL;
else
pdev = list_first_entry(&hwblk_idle_list,
struct platform_device,
archdata.entry);
spin_unlock_irqrestore(&hwblk_lock, flags);
if (pdev) {
mutex_lock(&pdev->archdata.mutex);
ret = __platform_pm_runtime_suspend(pdev);
/* at this point the platform device may be:
* suspended: ret = 0, FLAG_SUSP set, clock stopped
* failed: ret < 0, FLAG_IDLE set, clock stopped
*/
mutex_unlock(&pdev->archdata.mutex);
} else {
ret = -ENODEV;
}
} while (!ret);
}
/* this function gets called from cpuidle context when all devices in the
* main power domain are unused but some are counted as idle, ie the hwblk
* counter values are (HWBLK_CNT_USAGE == 0) && (HWBLK_CNT_IDLE != 0)
*/
void platform_pm_runtime_suspend_idle(void)
{
queue_work(pm_wq, &hwblk_work);
}
int platform_pm_runtime_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct pdev_archdata *ad = &pdev->archdata;
unsigned long flags;
int hwblk = ad->hwblk_id;
int ret = 0;
dev_dbg(dev, "platform_pm_runtime_suspend() [%d]\n", hwblk);
/* ignore off-chip platform devices */
if (!hwblk)
goto out;
/* interrupt context not allowed */
might_sleep();
/* catch misconfigured drivers not starting with resume */
if (test_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags)) {
ret = -EINVAL;
goto out;
}
/* serialize */
mutex_lock(&ad->mutex);
/* disable clock */
hwblk_disable(hwblk_info, hwblk);
/* put device on idle list */
spin_lock_irqsave(&hwblk_lock, flags);
list_add_tail(&pdev->archdata.entry, &hwblk_idle_list);
__set_bit(PDEV_ARCHDATA_FLAG_IDLE, &pdev->archdata.flags);
spin_unlock_irqrestore(&hwblk_lock, flags);
/* increase idle count */
hwblk_cnt_inc(hwblk_info, hwblk, HWBLK_CNT_IDLE);
/* at this point the platform device is:
* idle: ret = 0, FLAG_IDLE set, clock stopped
*/
mutex_unlock(&ad->mutex);
out:
dev_dbg(dev, "platform_pm_runtime_suspend() [%d] returns %d\n",
hwblk, ret);
return ret;
}
int platform_pm_runtime_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct pdev_archdata *ad = &pdev->archdata;
int hwblk = ad->hwblk_id;
int ret = 0;
dev_dbg(dev, "platform_pm_runtime_resume() [%d]\n", hwblk);
/* ignore off-chip platform devices */
if (!hwblk)
goto out;
/* interrupt context not allowed */
might_sleep();
/* serialize */
mutex_lock(&ad->mutex);
/* make sure device is removed from idle list */
platform_pm_runtime_not_idle(pdev);
/* decrease idle count */
if (!test_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags) &&
!test_bit(PDEV_ARCHDATA_FLAG_SUSP, &pdev->archdata.flags))
hwblk_cnt_dec(hwblk_info, hwblk, HWBLK_CNT_IDLE);
/* resume the device if needed */
ret = __platform_pm_runtime_resume(pdev);
/* the driver has been initialized now, so clear the init flag */
clear_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);
/* at this point the platform device may be:
* resumed: ret = 0, flags = 0, clock started
* failed: ret < 0, FLAG_SUSP set, clock stopped
*/
mutex_unlock(&ad->mutex);
out:
dev_dbg(dev, "platform_pm_runtime_resume() [%d] returns %d\n",
hwblk, ret);
return ret;
}
int platform_pm_runtime_idle(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
int hwblk = pdev->archdata.hwblk_id;
int ret = 0;
dev_dbg(dev, "platform_pm_runtime_idle() [%d]\n", hwblk);
/* ignore off-chip platform devices */
if (!hwblk)
goto out;
/* interrupt context not allowed, use pm_runtime_put()! */
might_sleep();
/* suspend synchronously to disable clocks immediately */
ret = pm_runtime_suspend(dev);
out:
dev_dbg(dev, "platform_pm_runtime_idle() [%d] done!\n", hwblk);
return ret;
}
static int platform_bus_notify(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device *dev = data;
struct platform_device *pdev = to_platform_device(dev);
int hwblk = pdev->archdata.hwblk_id;
/* ignore off-chip platform devices */
if (!hwblk)
return 0;
switch (action) {
case BUS_NOTIFY_ADD_DEVICE:
INIT_LIST_HEAD(&pdev->archdata.entry);
mutex_init(&pdev->archdata.mutex);
/* platform devices without drivers should be disabled */
hwblk_enable(hwblk_info, hwblk);
hwblk_disable(hwblk_info, hwblk);
/* make sure driver re-inits itself once */
__set_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);
break;
/* TODO: add BUS_NOTIFY_BIND_DRIVER and increase idle count */
case BUS_NOTIFY_BOUND_DRIVER:
/* keep track of number of devices in use per hwblk */
hwblk_cnt_inc(hwblk_info, hwblk, HWBLK_CNT_DEVICES);
break;
case BUS_NOTIFY_UNBOUND_DRIVER:
/* keep track of number of devices in use per hwblk */
hwblk_cnt_dec(hwblk_info, hwblk, HWBLK_CNT_DEVICES);
/* make sure driver re-inits itself once */
__set_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);
break;
case BUS_NOTIFY_DEL_DEVICE:
break;
}
return 0;
}
static struct notifier_block platform_bus_notifier = {
.notifier_call = platform_bus_notify
};
static int __init sh_pm_runtime_init(void)
{
INIT_WORK(&hwblk_work, platform_pm_runtime_work);
bus_register_notifier(&platform_bus_type, &platform_bus_notifier);
return 0;
}
core_initcall(sh_pm_runtime_init);
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