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author | Geert Uytterhoeven <geert+renesas@glider.be> | 2015-08-04 14:28:02 +0200 |
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committer | Simon Horman <horms+renesas@verge.net.au> | 2015-08-12 10:31:26 +0900 |
commit | 752b5ed5f6998e118626feea7375782c4cf5aad6 (patch) | |
tree | 553132209bbbdf91664f0cdb58d1f6c3535e4d13 /drivers/clk/shmobile/clk-mstp.c | |
parent | d770e558e21961ad6cfdf0ff7df0eb5d7d4f0754 (diff) | |
download | op-kernel-dev-752b5ed5f6998e118626feea7375782c4cf5aad6.zip op-kernel-dev-752b5ed5f6998e118626feea7375782c4cf5aad6.tar.gz |
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: 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>
Diffstat (limited to 'drivers/clk/shmobile/clk-mstp.c')
-rw-r--r-- | drivers/clk/shmobile/clk-mstp.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/drivers/clk/shmobile/clk-mstp.c b/drivers/clk/shmobile/clk-mstp.c index 2d2fe77..b1df7b2 100644 --- a/drivers/clk/shmobile/clk-mstp.c +++ b/drivers/clk/shmobile/clk-mstp.c @@ -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 */ |