[Patch v3 10/23] ARM: MM: Add DT binding for Feroceon L2 cache

[Jason Cooper]

+ rmk

Russell,

This patch (and two others after it) are necessary for the migration of
the kirkwood DT board code to mach-mvebu/.  Due to the complexity of the
move, (concurrent with adding three new SoCs to mach-mvebu), could you
please review these and provide Acks for us to take them through
arm-soc?

thx,

Jason.

On Wed, Feb 19, 2014 at 03:12:41PM +0100, Andrew Lunn wrote:
> Instantiate the L2 cache from DT. Indicate in DT where the cache
> control register is so that it is possible to enable/disable write
> through on the CPU.
> 
> Signed-off-by: Andrew Lunn <andrew at lunn.ch>
> cc: devicetree at vger.kernel.org
> ---
> v2:
> Change compatible strings to follow l2x0 convention
> Only expect register for kirkwood-cache.
> Default to write through if no DT node.
> Rename writethrough to wt-override to follow l2cc binding.
> Split kirkwood.dtsi change into a patch of its own.
> v3
> Remove wt-override from the binding
> Respect CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH
> ---
>  .../devicetree/bindings/arm/mrvl/feroceon.txt      | 16 ++++++++
>  arch/arm/include/asm/hardware/cache-feroceon-l2.h  |  2 +
>  arch/arm/mach-kirkwood/board-dt.c                  | 18 ++-------
>  arch/arm/mm/cache-feroceon-l2.c                    | 43 ++++++++++++++++++++++
>  4 files changed, 64 insertions(+), 15 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/arm/mrvl/feroceon.txt
> 
> diff --git a/Documentation/devicetree/bindings/arm/mrvl/feroceon.txt b/Documentation/devicetree/bindings/arm/mrvl/feroceon.txt
> new file mode 100644
> index 000000000000..0d244b999d10
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/mrvl/feroceon.txt
> @@ -0,0 +1,16 @@
> +* Marvell Feroceon Cache
> +
> +Required properties:
> +- compatible : Should be either "marvell,feroceon-cache" or
> +  	       "marvell,kirkwood-cache".
> +
> +Optional properties:
> +- reg        : Address of the L2 cache control register. Mandatory for
> +  	       "marvell,kirkwood-cache", not used by "marvell,feroceon-cache"
> +
> +
> +Example:
> +		l2: l2-cache at 20128 {
> +			compatible = "marvell,kirkwood-cache";
> +			reg = <0x20128 0x4>;
> +		};
> diff --git a/arch/arm/include/asm/hardware/cache-feroceon-l2.h b/arch/arm/include/asm/hardware/cache-feroceon-l2.h
> index 8edd330aabf6..12e1588dc4f1 100644
> --- a/arch/arm/include/asm/hardware/cache-feroceon-l2.h
> +++ b/arch/arm/include/asm/hardware/cache-feroceon-l2.h
> @@ -9,3 +9,5 @@
>   */
>  
>  extern void __init feroceon_l2_init(int l2_wt_override);
> +extern int __init feroceon_of_init(void);
> +
> diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
> index 29c246858d5a..ec0702c02d6c 100644
> --- a/arch/arm/mach-kirkwood/board-dt.c
> +++ b/arch/arm/mach-kirkwood/board-dt.c
> @@ -42,19 +42,6 @@ static void __init kirkwood_map_io(void)
>  	iotable_init(kirkwood_io_desc, ARRAY_SIZE(kirkwood_io_desc));
>  }
>  
> -static void __init kirkwood_l2_init(void)
> -{
> -#ifdef CONFIG_CACHE_FEROCEON_L2
> -#ifdef CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH
> -	writel(readl(L2_CONFIG_REG) | L2_WRITETHROUGH, L2_CONFIG_REG);
> -	feroceon_l2_init(1);
> -#else
> -	writel(readl(L2_CONFIG_REG) & ~L2_WRITETHROUGH, L2_CONFIG_REG);
> -	feroceon_l2_init(0);
> -#endif
> -#endif
> -}
> -
>  static struct resource kirkwood_cpufreq_resources[] = {
>  	[0] = {
>  		.start  = CPU_CONTROL_PHYS,
> @@ -211,8 +198,9 @@ static void __init kirkwood_dt_init(void)
>  
>  	BUG_ON(mvebu_mbus_dt_init());
>  
> -	kirkwood_l2_init();
> -
> +#ifdef CONFIG_CACHE_FEROCEON_L2
> +	feroceon_of_init();
> +#endif
>  	kirkwood_cpufreq_init();
>  	kirkwood_cpuidle_init();
>  
> diff --git a/arch/arm/mm/cache-feroceon-l2.c b/arch/arm/mm/cache-feroceon-l2.c
> index 898362e7972b..8dc1a2b5a8ed 100644
> --- a/arch/arm/mm/cache-feroceon-l2.c
> +++ b/arch/arm/mm/cache-feroceon-l2.c
> @@ -13,11 +13,16 @@
>   */
>  
>  #include <linux/init.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
>  #include <linux/highmem.h>
> +#include <linux/io.h>
>  #include <asm/cacheflush.h>
>  #include <asm/cp15.h>
>  #include <asm/hardware/cache-feroceon-l2.h>
>  
> +#define L2_WRITETHROUGH_KIRKWOOD	BIT(4)
> +
>  /*
>   * Low-level cache maintenance operations.
>   *
> @@ -350,3 +355,41 @@ void __init feroceon_l2_init(int __l2_wt_override)
>  	printk(KERN_INFO "Feroceon L2: Cache support initialised%s.\n",
>  			 l2_wt_override ? ", in WT override mode" : "");
>  }
> +#ifdef CONFIG_OF
> +static const struct of_device_id feroceon_ids[] __initconst = {
> +	{ .compatible = "marvell,kirkwood-cache"},
> +	{ .compatible = "marvell,feroceon-cache"},
> +	{}
> +};
> +
> +int __init feroceon_of_init(void)
> +{
> +	struct device_node *node;
> +	void __iomem *base;
> +	bool l2_wt_override = false;
> +	struct resource res;
> +
> +#if defined(CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH)
> +	l2_wt_override = true;
> +#endif
> +
> +	node = of_find_matching_node(NULL, feroceon_ids);
> +	if (node && of_device_is_compatible(node, "marvell,kirkwood-cache")) {
> +		if (of_address_to_resource(node, 0, &res))
> +			return -ENODEV;
> +
> +		base = ioremap(res.start, resource_size(&res));
> +		if (!base)
> +			return -ENOMEM;
> +
> +		if (l2_wt_override)
> +			writel(readl(base) | L2_WRITETHROUGH_KIRKWOOD, base);
> +		else
> +			writel(readl(base) & ~L2_WRITETHROUGH_KIRKWOOD, base);
> +	}
> +
> +	feroceon_l2_init(l2_wt_override);
> +
> +	return 0;
> +}
> +#endif
> -- 
> 1.8.5.3
>