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@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
.../bindings/arm/exynos/power_domain.txt | 13 +++-
arch/arm/mach-exynos/pm_domains.c | 82 ++++++++++++++++++++++
2 files changed, 94 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt
index 843b546..8ed914f 100644
--- a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt
+++ b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt
@@ -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 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 {
+ /* ... */
+ power-domain = <&lcd0>;
+ /* ... */
+ };
diff --git a/arch/arm/mach-exynos/pm_domains.c b/arch/arm/mach-exynos/pm_domains.c
index 5b7ce7e..7b3b8a3 100644
--- a/arch/arm/mach-exynos/pm_domains.c
+++ b/arch/arm/mach-exynos/pm_domains.c
@@ -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, "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
--
1.8.0
--
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