/*
* Exynos Generic power domain support.
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* Implementation of Exynos specific power domain control which is used in
* conjunction with runtime-pm. Support for both device-tree and non-device-tree
* based power domain support is included.
*
* 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/io.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/pm_domain.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/sched.h>
#define INT_LOCAL_PWR_EN 0x7
#define MAX_CLK_PER_DOMAIN 4
/*
* Exynos specific wrapper around the generic power domain
*/
struct exynos_pm_domain {
void __iomem *base;
char const *name;
bool is_off;
struct generic_pm_domain pd;
struct clk *oscclk;
struct clk *clk[MAX_CLK_PER_DOMAIN];
struct clk *pclk[MAX_CLK_PER_DOMAIN];
};
static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
{
struct exynos_pm_domain *pd;
void __iomem *base;
u32 timeout, pwr;
char *op;
pd = container_of(domain, struct exynos_pm_domain, pd);
base = pd->base;
/* Set oscclk before powering off a domain*/
if (!power_on) {
int i;
for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
if (IS_ERR(pd->clk[i]))
break;
if (clk_set_parent(pd->clk[i], pd->oscclk))
pr_err("%s: error setting oscclk as parent to clock %d\n",
pd->name, i);
}
}
pwr = power_on ? INT_LOCAL_PWR_EN : 0;
__raw_writel(pwr, base);
/* Wait max 1ms */
timeout = 10;
while ((__raw_readl(base + 0x4) & INT_LOCAL_PWR_EN) != pwr) {
if (!timeout) {
op = (power_on) ? "enable" : "disable";
pr_err("Power domain %s %s failed\n", domain->name, op);
return -ETIMEDOUT;
}
timeout--;
cpu_relax();
usleep_range(80, 100);
}
/* Restore clocks after powering on a domain*/
if (power_on) {
int i;
for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
if (IS_ERR(pd->clk[i]))
break;
if (clk_set_parent(pd->clk[i], pd->pclk[i]))
pr_err("%s: error setting parent to clock%d\n",
pd->name, i);
}
}
return 0;
}
static int exynos_pd_power_on(struct generic_pm_domain *domain)
{
return exynos_pd_power(domain, true);
}
static int exynos_pd_power_off(struct generic_pm_domain *domain)
{
return exynos_pd_power(domain, false);
}
static void exynos_add_device_to_domain(struct exynos_pm_domain *pd,
struct device *dev)
{
int ret;
dev_dbg(dev, "adding to power domain %s\n", pd->pd.name);
while (1) {
ret = pm_genpd_add_device(&pd->pd, dev);
if (ret != -EAGAIN)
break;
cond_resched();
}
pm_genpd_dev_need_restore(dev, true);
}
static void exynos_remove_device_from_domain(struct device *dev)
{
struct generic_pm_domain *genpd = dev_to_genpd(dev);
int ret;
dev_dbg(dev, "removing from power domain %s\n", genpd->name);
while (1) {
ret = pm_genpd_remove_device(genpd, dev);
if (ret != -EAGAIN)
break;
cond_resched();
}
}
static void exynos_read_domain_from_dt(struct device *dev)
{
struct platform_device *pd_pdev;
struct exynos_pm_domain *pd;
struct device_node *node;
node = of_parse_phandle(dev->of_node, "samsung,power-domain", 0);
if (!node)
return;
pd_pdev = of_find_device_by_node(node);
if (!pd_pdev)
return;
pd = platform_get_drvdata(pd_pdev);
exynos_add_device_to_domain(pd, dev);
}
static int exynos_pm_notifier_call(struct notifier_block *nb,
unsigned long event, void *data)
{
struct device *dev = data;
switch (event) {
case BUS_NOTIFY_BIND_DRIVER:
if (dev->of_node)
exynos_read_domain_from_dt(dev);
break;
case BUS_NOTIFY_UNBOUND_DRIVER:
exynos_remove_device_from_domain(dev);
break;
}
return NOTIFY_DONE;
}
static struct notifier_block platform_nb = {
.notifier_call = exynos_pm_notifier_call,
};
static __init int exynos4_pm_init_power_domain(void)
{
struct platform_device *pdev;
struct device_node *np;
for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") {
struct exynos_pm_domain *pd;
int on, i;
struct device *dev;
pdev = of_find_device_by_node(np);
dev = &pdev->dev;
pd = kzalloc(sizeof(*pd), GFP_KERNEL);
if (!pd) {
pr_err("%s: failed to allocate memory for domain\n",
__func__);
return -ENOMEM;
}
pd->pd.name = kstrdup(np->name, GFP_KERNEL);
pd->name = pd->pd.name;
pd->base = of_iomap(np, 0);
pd->pd.power_off = exynos_pd_power_off;
pd->pd.power_on = exynos_pd_power_on;
pd->pd.of_node = np;
pd->oscclk = clk_get(dev, "oscclk");
if (IS_ERR(pd->oscclk))
goto no_clk;
for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
char clk_name[8];
snprintf(clk_name, sizeof(clk_name), "clk%d", i);
pd->clk[i] = clk_get(dev, clk_name);
if (IS_ERR(pd->clk[i]))
break;
snprintf(clk_name, sizeof(clk_name), "pclk%d", i);
pd->pclk[i] = clk_get(dev, clk_name);
if (IS_ERR(pd->pclk[i])) {
clk_put(pd->clk[i]);
pd->clk[i] = ERR_PTR(-EINVAL);
break;
}
}
if (IS_ERR(pd->clk[0]))
clk_put(pd->oscclk);
no_clk:
platform_set_drvdata(pdev, pd);
on = __raw_readl(pd->base + 0x4) & INT_LOCAL_PWR_EN;
pm_genpd_init(&pd->pd, NULL, !on);
}
bus_register_notifier(&platform_bus_type, &platform_nb);
return 0;
}
arch_initcall(exynos4_pm_init_power_domain);
