ARM: EXYNOS: Bind devices to power domains using DT

This patch adds a way to specify bindings between devices and power
domains using device tree.

A device can be bound to particular power domain by adding a
power-domain property containing a phandle to the domain. The device
will be bound to the domain before binding a driver to it and unbound
after unbinding a driver from it.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This commit is contained in:
Tomasz Figa 2012-11-22 00:21:17 +09:00 committed by Kukjin Kim
parent 7add0ec0fe
commit 8a65d2365d
2 changed files with 94 additions and 1 deletions

View File

@ -4,14 +4,25 @@ Exynos processors include support for multiple power domains which are used
to gate power to one or more peripherals on the processor.
Required Properties:
- compatiable: should be one of the following.
- compatible: should be one of the following.
* samsung,exynos4210-pd - for exynos4210 type power domain.
- reg: physical base address of the controller and length of memory mapped
region.
Node of a device using power domains must have a samsung,power-domain property
defined with a phandle to respective power domain.
Example:
lcd0: power-domain-lcd0 {
compatible = "samsung,exynos4210-pd";
reg = <0x10023C00 0x10>;
};
Example of the node using power domain:
node {
/* ... */
samsung,power-domain = <&lcd0>;
/* ... */
};

View File

@ -19,6 +19,8 @@
#include <linux/pm_domain.h>
#include <linux/delay.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/sched.h>
#include <mach/regs-pmu.h>
#include <plat/devs.h>
@ -83,14 +85,89 @@ static struct exynos_pm_domain PD = { \
}
#ifdef CONFIG_OF
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 exynos_pm_dt_parse_domains(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;
pdev = of_find_device_by_node(np);
pd = kzalloc(sizeof(*pd), GFP_KERNEL);
if (!pd) {
pr_err("%s: failed to allocate memory for domain\n",
@ -105,10 +182,15 @@ static __init int exynos_pm_dt_parse_domains(void)
pd->pd.power_on = exynos_pd_power_on;
pd->pd.of_node = np;
platform_set_drvdata(pdev, pd);
on = __raw_readl(pd->base + 0x4) & S5P_INT_LOCAL_PWR_EN;
pm_genpd_init(&pd->pd, NULL, !on);
}
bus_register_notifier(&platform_bus_type, &platform_nb);
return 0;
}
#else