Messages in this thread | | | Date | Mon, 14 Nov 2016 13:48:13 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH 01/16] ARM: scu: Provide support for parsing SCU device node to enable SCU |
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This should be sent _to_ me because it's touching generic ARM code. Thanks.
On Mon, Nov 14, 2016 at 10:31:56AM +0530, Pankaj Dubey wrote: > Many platforms are duplicating code for enabling SCU, lets add > common code to enable SCU by parsing SCU device node so the duplication > in each platform can be avoided. > > CC: Krzysztof Kozlowski <krzk@kernel.org> > CC: Jisheng Zhang <jszhang@marvell.com> > CC: Russell King <linux@armlinux.org.uk> > CC: Dinh Nguyen <dinguyen@opensource.altera.com> > CC: Patrice Chotard <patrice.chotard@st.com> > CC: Linus Walleij <linus.walleij@linaro.org> > CC: Liviu Dudau <liviu.dudau@arm.com> > CC: Ray Jui <rjui@broadcom.com> > CC: Stephen Warren <swarren@wwwdotorg.org> > CC: Heiko Stuebner <heiko@sntech.de> > CC: Shawn Guo <shawnguo@kernel.org> > CC: Michal Simek <michal.simek@xilinx.com> > CC: Wei Xu <xuwei5@hisilicon.com> > CC: Andrew Lunn <andrew@lunn.ch> > CC: Jun Nie <jun.nie@linaro.org> > Suggested-by: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com> > --- > arch/arm/include/asm/smp_scu.h | 4 +++ > arch/arm/kernel/smp_scu.c | 56 ++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 60 insertions(+) > > diff --git a/arch/arm/include/asm/smp_scu.h b/arch/arm/include/asm/smp_scu.h > index bfe163c..fdeec07 100644 > --- a/arch/arm/include/asm/smp_scu.h > +++ b/arch/arm/include/asm/smp_scu.h > @@ -39,8 +39,12 @@ static inline int scu_power_mode(void __iomem *scu_base, unsigned int mode) > > #if defined(CONFIG_SMP) && defined(CONFIG_HAVE_ARM_SCU) > void scu_enable(void __iomem *scu_base); > +void __iomem *of_scu_get_base(void); > +int of_scu_enable(void); > #else > static inline void scu_enable(void __iomem *scu_base) {} > +static inline void __iomem *of_scu_get_base(void) {return NULL; } > +static inline int of_scu_enable(void) {return 0; } > #endif > > #endif > diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c > index 72f9241..d0ac3ed 100644 > --- a/arch/arm/kernel/smp_scu.c > +++ b/arch/arm/kernel/smp_scu.c > @@ -10,6 +10,7 @@ > */ > #include <linux/init.h> > #include <linux/io.h> > +#include <linux/of_address.h> > > #include <asm/smp_plat.h> > #include <asm/smp_scu.h> > @@ -70,6 +71,61 @@ void scu_enable(void __iomem *scu_base) > */ > flush_cache_all(); > } > + > +static const struct of_device_id scu_match[] = { > + { .compatible = "arm,cortex-a9-scu", }, > + { .compatible = "arm,cortex-a5-scu", }, > + { } > +}; > + > +/* > + * Helper API to get SCU base address > + * In case platform DT do not have SCU node, or iomap fails > + * this call will fallback and will try to map via call to > + * scu_a9_get_base. > + * This will return ownership of scu_base to the caller > + */ > +void __iomem *of_scu_get_base(void) > +{ > + unsigned long base = 0; > + struct device_node *np; > + void __iomem *scu_base; > + > + np = of_find_matching_node(NULL, scu_match); > + scu_base = of_iomap(np, 0); > + of_node_put(np); > + if (!scu_base) { > + pr_err("%s failed to map scu_base via DT\n", __func__); > + if (scu_a9_has_base()) { > + base = scu_a9_get_base(); > + scu_base = ioremap(base, SZ_4K); > + } > + if (!scu_base) { > + pr_err("%s failed to map scu_base\n", __func__); > + return IOMEM_ERR_PTR(-ENOMEM);
I can't see the point of using error-pointers here - it's not like we really know why we're failing, so just return NULL.
> + } > + } > + return scu_base; > +} > + > +/* > + * Enable SCU via mapping scu_base DT > + * If scu_base mapped successfully scu will be enabled and in case of > + * failure if will return non-zero error code > + */ > +int of_scu_enable(void) > +{ > + void __iomem *scu_base; > + > + scu_base = of_scu_get_base(); > + if (!IS_ERR(scu_base)) { > + scu_enable(scu_base); > + iounmap(scu_base); > + return 0; > + } > + return PTR_ERR(scu_base);
and just return your -ENOMEM here.
-- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.
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