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clk: shmobile: Add CPG/MSTP Clock Domain support

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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: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
This commit is contained in:
Geert Uytterhoeven 2015-08-04 14:28:02 +02:00 committed by Simon Horman
parent d770e558e2
commit 752b5ed5f6
2 changed files with 99 additions and 0 deletions
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87
drivers/clk/shmobile/clk-mstp.c
View File

@ -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 */

12
include/linux/clk/shmobile.h
View File

@ -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