Subject: [PATCH RESEND v3] ARM: kirkwood: retain MAC address for DT ethernet

From: [email-masked] (Andrew Lunn)
Date: Fri, 4 Oct 2013 15:28:47 +0200

On Fri, Oct 04, 2013 at 12:17:22PM +0200, Sebastian Hesselbarth wrote:
> Ethernet IP on Kirkwood SoCs loose their MAC address register content
> if clock gated. To allow modular ethernet driver setups and gated clocks
> also on non-DT capable bootloaders, we fixup port device nodes with no
> valid MAC address property. This patch copies MAC address register
> contents set up by bootloaders early, notably before ethernet clocks
> are gated. While at it, also reorder call sequence in _dt_init.
> 
> Signed-off-by: Sebastian Hesselbarth <[email-masked]>
> ---
> Changelog:
> v2->v3:
> - make use of new public clk_is_enabled (adds dependency [1])
> - add warning about gated clock && missing MAC property
>   (Suggested by Jason Gunthorpe)
> v1->v2:
> - check for gated clock before accessing eth registers
>   (Suggested by Andrew Lunn)
> 
> [1] http://www.spinics.net/lists/arm-kernel/msg277392.html
> 
> Cc: Jason Cooper <[email-masked]>
> Cc: Andrew Lunn <[email-masked]>
> Cc: Russell King <[email-masked]>
> Cc: Grant Likely <[email-masked]>
> Cc: Benjamin Herrenschmidt <[email-masked]>
> Cc: Jason Gunthorpe <[email-masked]>
> Cc: Ezequiel Garcia <[email-masked]>
> Cc: Mike Turquette <[email-masked]>
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-kernel at vger.kernel.org
> ---
>  arch/arm/mach-kirkwood/board-dt.c |   85 +++++++++++++++++++++++++++++++++++--
>  1 file changed, 82 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
> index 82d3ad8..28e952b 100644
> --- a/arch/arm/mach-kirkwood/board-dt.c
> +++ b/arch/arm/mach-kirkwood/board-dt.c
> @@ -13,6 +13,8 @@
>  #include <linux/kernel.h>
>  #include <linux/init.h>
>  #include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_net.h>
>  #include <linux/of_platform.h>
>  #include <linux/clk-provider.h>
>  #include <linux/clocksource.h>
> @@ -66,6 +68,84 @@ static void __init kirkwood_legacy_clk_init(void)
>  	clk_prepare_enable(clk);
>  }
>  
> +#define MV643XX_ETH_MAC_ADDR_LOW	0x0414
> +#define MV643XX_ETH_MAC_ADDR_HIGH	0x0418
> +
> +static void __init kirkwood_dt_eth_fixup(void)
> +{
> +	struct device_node *np;
> +
> +	/*
> +	 * The ethernet interfaces forget the MAC address assigned by u-boot
> +	 * if the clocks are turned off. Usually, u-boot on kirkwood boards
> +	 * has no DT support to properly set local-mac-address property.
> +	 * As a workaround, we get the MAC address from mv643xx_eth registers
> +	 * and update the port device node if no valid MAC address is set.
> +	 */
> +	for_each_compatible_node(np, NULL, "marvell,kirkwood-eth-port") {
> +		struct device_node *pnp = of_get_parent(np);
> +		struct clk *clk;
> +		struct property *pmac;
> +		void __iomem *io;
> +		u8 *macaddr;
> +		u32 reg;
> +
> +		if (!pnp)
> +			continue;
> +
> +		/* skip disabled nodes or nodes with valid MAC address*/
> +		if (!of_device_is_available(pnp) || of_get_mac_address(np))
> +			continue;
> +
> +		/* skip already gated ports, spill warning about missing MAC */
> +		clk = of_clk_get(pnp, 0);
> +		if (!clk_is_enabled(clk)) {
> +			pr_err(FW_BUG "%s: gated port has no local-mac-address set\n",
> +			       np->full_name);
> +			clk_put(clk);
> +			continue;
> +		}
> +		clk_put(clk);
> +
> +		/* store MAC address register contents in local-mac-address */
> +		pr_err(FW_BUG "%s: local-mac-address is not set\n",
> +		       np->full_name);

Hi Sebastian

I've tested on Kirkwood with a modular build. Works as expected.

My only question is the pr_err(FW_BUF above. My guess is, 99% of
orion5x, kirkwood, and Dove systems will never get a U-boot with DT
support, which sets the local-mac-address property. I would drop it
down to FW_INFO, or drop the message altogether.

Otherwise,

Tested-by: Andrew Lunn <[email-masked]>

	   Andrew

> +
> +		io = of_iomap(pnp, 0);
> +		if (!io)
> +			continue;
> +
> +		pmac = kzalloc(sizeof(*pmac) + 6, GFP_KERNEL);
> +		if (!pmac) {
> +			iounmap(io);
> +			continue;
> +		}
> +
> +		pmac->value = pmac + 1;
> +		pmac->length = 6;
> +		pmac->name = kstrdup("local-mac-address", GFP_KERNEL);
> +		if (!pmac->name) {
> +			kfree(pmac);
> +			iounmap(io);
> +			continue;
> +		}
> +
> +		macaddr = pmac->value;
> +		reg = readl(io + MV643XX_ETH_MAC_ADDR_HIGH);
> +		macaddr[0] = (reg >> 24) & 0xff;
> +		macaddr[1] = (reg >> 16) & 0xff;
> +		macaddr[2] = (reg >> 8) & 0xff;
> +		macaddr[3] = reg & 0xff;
> +
> +		reg = readl(io + MV643XX_ETH_MAC_ADDR_LOW);
> +		macaddr[4] = (reg >> 8) & 0xff;
> +		macaddr[5] = reg & 0xff;
> +
> +		of_update_property(np, pmac);
> +		iounmap(io);
> +	}
> +}
> +
>  static void __init kirkwood_dt_time_init(void)
>  {
>  	of_clk_init(NULL);
> @@ -97,11 +177,10 @@ static void __init kirkwood_dt_init(void)
>  	kirkwood_l2_init();
>  
>  	kirkwood_cpufreq_init();
> -
> +	kirkwood_cpuidle_init();
>  	/* Setup clocks for legacy devices */
>  	kirkwood_legacy_clk_init();
> -
> -	kirkwood_cpuidle_init();
> +	kirkwood_dt_eth_fixup();
>  
>  #ifdef CONFIG_KEXEC
>  	kexec_reinit = kirkwood_enable_pcie;
> -- 
> 1.7.10.4
>