/*
* arch/arm/mach-shmobile/pm_runtime.c
*
* Runtime PM support code for SuperH Mobile ARM
*
* Copyright (C) 2009-2010 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/clk.h>
#include <linux/sh_clk.h>
#include <linux/bitmap.h>
#ifdef CONFIG_PM_RUNTIME
#define BIT_ONCE 0
#define BIT_ACTIVE 1
#define BIT_CLK_ENABLED 2
struct pm_runtime_data {
unsigned long flags;
struct clk *clk;
};
static void __devres_release(struct device *dev, void *res)
{
struct pm_runtime_data *prd = res;
dev_dbg(dev, "__devres_release()\n");
if (test_bit(BIT_CLK_ENABLED, &prd->flags))
clk_disable(prd->clk);
if (test_bit(BIT_ACTIVE, &prd->flags))
clk_put(prd->clk);
}
static struct pm_runtime_data *__to_prd(struct device *dev)
{
return devres_find(dev, __devres_release, NULL, NULL);
}
static void platform_pm_runtime_init(struct device *dev,
struct pm_runtime_data *prd)
{
if (prd && !test_and_set_bit(BIT_ONCE, &prd->flags)) {
prd->clk = clk_get(dev, NULL);
if (!IS_ERR(prd->clk)) {
set_bit(BIT_ACTIVE, &prd->flags);
dev_info(dev, "clocks managed by runtime pm\n");
}
}
}
static void platform_pm_runtime_bug(struct device *dev,
struct pm_runtime_data *prd)
{
if (prd && !test_and_set_bit(BIT_ONCE, &prd->flags))
dev_err(dev, "runtime pm suspend before resume\n");
}
int platform_pm_runtime_suspend(struct device *dev)
{
struct pm_runtime_data *prd = __to_prd(dev);
dev_dbg(dev, "platform_pm_runtime_suspend()\n");
platform_pm_runtime_bug(dev, prd);
if (prd && test_bit(BIT_ACTIVE, &prd->flags)) {
clk_disable(prd->clk);
clear_bit(BIT_CLK_ENABLED, &prd->flags);
}
return 0;
}
int platform_pm_runtime_resume(struct device *dev)
{
struct pm_runtime_data *prd = __to_prd(dev);
dev_dbg(dev, "platform_pm_runtime_resume()\n");
platform_pm_runtime_init(dev, prd);
if (prd && test_bit(BIT_ACTIVE, &prd->flags)) {
clk_enable(prd->clk);
set_bit(BIT_CLK_ENABLED, &prd->flags);
}
return 0;
}
int platform_pm_runtime_idle(struct device *dev)
{
/* suspend synchronously to disable clocks immediately */
return pm_runtime_suspend(dev);
}
static int platform_bus_notify(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device *dev = data;
struct pm_runtime_data *prd;
dev_dbg(dev, "platform_bus_notify() %ld !\n", action);
if (action == BUS_NOTIFY_BIND_DRIVER) {
prd = devres_alloc(__devres_release, sizeof(*prd), GFP_KERNEL);
if (prd)
devres_add(dev, prd);
else
dev_err(dev, "unable to alloc memory for runtime pm\n");
}
return 0;
}
#else /* CONFIG_PM_RUNTIME */
static int platform_bus_notify(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device *dev = data;
struct clk *clk;
dev_dbg(dev, "platform_bus_notify() %ld !\n", action);
switch (action) {
case BUS_NOTIFY_BIND_DRIVER:
clk = clk_get(dev, NULL);
if (!IS_ERR(clk)) {
clk_enable(clk);
clk_put(clk);
dev_info(dev, "runtime pm disabled, clock forced on\n");
}
break;
case BUS_NOTIFY_UNBOUND_DRIVER:
clk = clk_get(dev, NULL);
if (!IS_ERR(clk)) {
clk_disable(clk);
clk_put(clk);
dev_info(dev, "runtime pm disabled, clock forced off\n");
}
break;
}
return 0;
}
#endif /* CONFIG_PM_RUNTIME */
static struct notifier_block platform_bus_notifier = {
.notifier_call = platform_bus_notify
};
static int __init sh_pm_runtime_init(void)
{
bus_register_notifier(&platform_bus_type, &platform_bus_notifier);
return 0;
}
core_initcall(sh_pm_runtime_init);
