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 <k...@kernel.org>
> CC: Jisheng Zhang <jszh...@marvell.com>
> CC: Russell King <li...@armlinux.org.uk>
> CC: Dinh Nguyen <dingu...@opensource.altera.com>
> CC: Patrice Chotard <patrice.chot...@st.com>
> CC: Linus Walleij <linus.wall...@linaro.org>
> CC: Liviu Dudau <liviu.du...@arm.com>
> CC: Ray Jui <r...@broadcom.com>
> CC: Stephen Warren <swar...@wwwdotorg.org>
> CC: Heiko Stuebner <he...@sntech.de>
> CC: Shawn Guo <shawn...@kernel.org>
> CC: Michal Simek <michal.si...@xilinx.com>
> CC: Wei Xu <xuw...@hisilicon.com>
> CC: Andrew Lunn <and...@lunn.ch>
> CC: Jun Nie <jun....@linaro.org>
> Suggested-by: Arnd Bergmann <a...@arndb.de>
> Signed-off-by: Pankaj Dubey <pankaj.du...@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.
--
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