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Commit 752b5ed5 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Simon Horman
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clk: shmobile: Add CPG/MSTP Clock Domain support 



Add Clock Domain support to the Clock Pulse Generator (CPG) Module Stop
(MSTP) Clocks driver using the generic PM Domain.  This allows to
power-manage the module clocks of SoC devices that are part of the
CPG/MSTP Clock Domain using Runtime PM, or for system suspend/resume.

SoC devices that are part of the CPG/MSTP Clock Domain and can be
power-managed through an MSTP clock should be tagged in DT with a
proper "power-domains" property.

The CPG/MSTP Clock Domain code will scan such devices for clocks that
are suitable for power-managing the device, by looking for a clock that
is compatible with "renesas,cpg-mstp-clocks".

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Reviewed-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: default avatarKevin Hilman <khilman@linaro.org>
Signed-off-by: default avatarSimon Horman <horms+renesas@verge.net.au>
parent d770e558

drivers/clk/shmobile/clk-mstp.c

+87 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
 * R-Car MSTP clocks

 *

 * Copyright (C) 2013 Ideas On Board SPRL

 * Copyright (C) 2015 Glider bvba

 *

 * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

 *
@@ -10,11 +11,16 @@ 
 * the Free Software Foundation; version 2 of the License.

 */



#include <linux/clk.h>

#include <linux/clk-provider.h>

#include <linux/clkdev.h>

#include <linux/clk/shmobile.h>

#include <linux/device.h>

#include <linux/io.h>

#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/pm_clock.h>

#include <linux/pm_domain.h>

#include <linux/spinlock.h>



/*
@@ -236,3 +242,84 @@ static void __init cpg_mstp_clocks_init(struct device_node *np) 
	of_clk_add_provider(np, of_clk_src_onecell_get, &group->data);

}

CLK_OF_DECLARE(cpg_mstp_clks, "renesas,cpg-mstp-clocks", cpg_mstp_clocks_init);





#ifdef CONFIG_PM_GENERIC_DOMAINS_OF

int cpg_mstp_attach_dev(struct generic_pm_domain *domain, struct device *dev)

{

	struct device_node *np = dev->of_node;

	struct of_phandle_args clkspec;

	struct clk *clk;

	int i = 0;

	int error;



	while (!of_parse_phandle_with_args(np, "clocks", "#clock-cells", i,

					   &clkspec)) {

		if (of_device_is_compatible(clkspec.np,

					    "renesas,cpg-mstp-clocks"))

			goto found;



		of_node_put(clkspec.np);

		i++;

	}



	return 0;



found:

	clk = of_clk_get_from_provider(&clkspec);

	of_node_put(clkspec.np);



	if (IS_ERR(clk))

		return PTR_ERR(clk);



	error = pm_clk_create(dev);

	if (error) {

		dev_err(dev, "pm_clk_create failed %d\n", error);

		goto fail_put;

	}



	error = pm_clk_add_clk(dev, clk);

	if (error) {

		dev_err(dev, "pm_clk_add_clk %pC failed %d\n", clk, error);

		goto fail_destroy;

	}



	return 0;



fail_destroy:

	pm_clk_destroy(dev);

fail_put:

	clk_put(clk);

	return error;

}



void cpg_mstp_detach_dev(struct generic_pm_domain *domain, struct device *dev)

{

	if (!list_empty(&dev->power.subsys_data->clock_list))

		pm_clk_destroy(dev);

}



void __init cpg_mstp_add_clk_domain(struct device_node *np)

{

	struct generic_pm_domain *pd;

	u32 ncells;



	if (of_property_read_u32(np, "#power-domain-cells", &ncells)) {

		pr_warn("%s lacks #power-domain-cells\n", np->full_name);

		return;

	}



	pd = kzalloc(sizeof(*pd), GFP_KERNEL);

	if (!pd)

		return;



	pd->name = np->name;



	pd->flags = GENPD_FLAG_PM_CLK;

	pm_genpd_init(pd, &simple_qos_governor, false);

	pd->attach_dev = cpg_mstp_attach_dev;

	pd->detach_dev = cpg_mstp_detach_dev;



	of_genpd_add_provider_simple(np, pd);

}

#endif /* !CONFIG_PM_GENERIC_DOMAINS_OF */

include/linux/clk/shmobile.h

+12 −0
Original line number Diff line number Diff line
@@ -16,8 +16,20 @@ 


#include <linux/types.h>



struct device;

struct device_node;

struct generic_pm_domain;



void r8a7778_clocks_init(u32 mode);

void r8a7779_clocks_init(u32 mode);

void rcar_gen2_clocks_init(u32 mode);



#ifdef CONFIG_PM_GENERIC_DOMAINS_OF

void cpg_mstp_add_clk_domain(struct device_node *np);

int cpg_mstp_attach_dev(struct generic_pm_domain *domain, struct device *dev);

void cpg_mstp_detach_dev(struct generic_pm_domain *domain, struct device *dev);

#else

static inline void cpg_mstp_add_clk_domain(struct device_node *np) {}

#endif



#endif