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Commit 8a65d236 authored by Tomasz Figa's avatar Tomasz Figa Committed by Kukjin Kim
Browse files

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: default avatarTomasz Figa <t.figa@samsung.com>
Signed-off-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: default avatarKukjin Kim <kgene.kim@samsung.com>
parent 7add0ec0

Documentation/devicetree/bindings/arm/exynos/power_domain.txt

+12 −1
Original line number Diff line number Diff line
@@ -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>;

		/* ... */

	};

arch/arm/mach-exynos/pm_domains.c

+82 −0
Original line number Diff line number Diff line
@@ -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