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 <redacted>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 .../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 __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
--

1.7.12