| Message ID | 1432839219-475-2-git-send-email-geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, May 28, 2015 at 8:53 PM, Geert Uytterhoeven <geert+renesas@glider.be> wrote: > 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 > Clock Domain using Runtime PM, or for system suspend/resume. > > SoC devices that are part of a CPG Clock Domain and can be > power-managed through an MSTP clock should be tagged in DT with a > proper "power-domains" property. > > The CPG 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> > Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> > Reviewed-by: Kevin Hilman <khilman@linaro.org> > --- > v2: > - Add Acked-by and Reviewed-by, > - Move core CPG Clock Domain code from the R-Car Gen2 driver to the > CPG MSTP Clocks driver, as it's generic, and can be used on other > Renesas SoCs that have a CPG/MSTP block, > - Scan for an MSTP clock instead of using the first clock tied to the > device (con_id NULL), > - Extract R-Car Gen2 specifics to a separate patch. > --- > drivers/clk/shmobile/clk-mstp.c | 86 ++++++++++++++++++++++++++++++++++++ > drivers/clk/shmobile/clk-rcar-gen2.c | 2 + > include/linux/clk/shmobile.h | 12 +++++ > 3 files changed, 100 insertions(+) > > diff --git a/drivers/clk/shmobile/clk-mstp.c b/drivers/clk/shmobile/clk-mstp.c > index 2d2fe773ac8168f9..619f3eccefd4884f 100644 > --- a/drivers/clk/shmobile/clk-mstp.c > +++ b/drivers/clk/shmobile/clk-mstp.c > @@ -236,3 +241,84 @@ 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) > +{ > + pm_clk_destroy(dev); This should only be done if cpg_mstp_attach_dev() actually added a clock, i.e. if (!list_empty(&dev->power.subsys_data->clock_list)) pm_clk_destroy(dev); Else it will free the subsys_data allocated by genpd_alloc_dev_data() prematurely, and genpd_free_dev_data() will crash when dereferencing dev->power.subsys_data. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
diff --git a/drivers/clk/shmobile/clk-mstp.c b/drivers/clk/shmobile/clk-mstp.c index 2d2fe773ac8168f9..619f3eccefd4884f 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> * @@ -12,9 +13,13 @@ #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 +241,84 @@ 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) +{ + 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. Clocks may fail.\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 */ diff --git a/drivers/clk/shmobile/clk-rcar-gen2.c b/drivers/clk/shmobile/clk-rcar-gen2.c index acfb6d7dbd6bc049..c7fde69d455e38c4 100644 --- a/drivers/clk/shmobile/clk-rcar-gen2.c +++ b/drivers/clk/shmobile/clk-rcar-gen2.c @@ -18,6 +18,8 @@ #include <linux/math64.h> #include <linux/of.h> #include <linux/of_address.h> +#include <linux/pm_clock.h> +#include <linux/pm_domain.h> #include <linux/spinlock.h> struct rcar_gen2_cpg { diff --git a/include/linux/clk/shmobile.h b/include/linux/clk/shmobile.h index 63a8159c4e64153d..cb19cc1865ca5cfb 100644 --- a/include/linux/clk/shmobile.h +++ b/include/linux/clk/shmobile.h @@ -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