diff mbox

[1/2] ARM: kirkwood: retain MAC address for DT ethernet

Message ID 1380804294-13726-1-git-send-email-sebastian.hesselbarth@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Sebastian Hesselbarth Oct. 3, 2013, 12:44 p.m. UTC
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 <sebastian.hesselbarth@gmail.com>
---
- Added Benjamin and Grant who where part of the discussion last time
  and gave valuable input on DT fixups.
- Patches are based on v3.12-rc1 and depend on latest mv643xx_eth
  fixes applied yesterday by David Miller [1].

[1] https://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=569943d0639c85a451ea853087cbd5f738247dd9

Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
 arch/arm/mach-kirkwood/board-dt.c |   72 +++++++++++++++++++++++++++++++++++--
 1 file changed, 69 insertions(+), 3 deletions(-)

Comments

Andrew Lunn Oct. 3, 2013, 1:47 p.m. UTC | #1
On Thu, Oct 03, 2013 at 02:44:53PM +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 <sebastian.hesselbarth@gmail.com>
> ---
> - Added Benjamin and Grant who where part of the discussion last time
>   and gave valuable input on DT fixups.
> - Patches are based on v3.12-rc1 and depend on latest mv643xx_eth
>   fixes applied yesterday by David Miller [1].
> 
> [1] https://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=569943d0639c85a451ea853087cbd5f738247dd9
> 
> Cc: Jason Cooper <jason@lakedaemon.net>
> Cc: Andrew Lunn <andrew@lunn.ch>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: Grant Likely <grant.likely@linaro.org>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
> Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  arch/arm/mach-kirkwood/board-dt.c |   72 +++++++++++++++++++++++++++++++++++--
>  1 file changed, 69 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
> index 82d3ad8..a2974ad 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 +68,71 @@ 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 property *pmac;
> +		void __iomem *io;
> +		u8 *macaddr;
> +		u32 reg;
> +
> +		if (!pnp || !of_device_is_available(pnp))
> +			continue;
> +
> +		if (of_get_mac_address(np))
> +			continue;
> +
> +		pr_err(FW_BUG "%s: local-mac-address is not set\n",
> +		       np->full_name);
> +
> +		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;

Hi Sebastian

What happens if at this point, the ethernet clock is gated off?  I
assume the CPU locks solid, requiring a power cycle.

It would be a bit of an odd situation, u-boot has disabled the clock,
yet we have a DT node for the device and no valid local-mac-address.
We do however know that Jason Gunthorpe u-boot does gate the second
ethernet for his board, so it is not completely impossible to hit this
situation, particularly when bringing up a new board.

Are we too early in the boot to actually use the clock information in
the node to find it, and clk_prepare_enable() it before making the
access?

	Andrew
Sebastian Hesselbarth Oct. 3, 2013, 3:15 p.m. UTC | #2
On October 3, 2013 3:47:24 PM Andrew Lunn <andrew@lunn.ch> wrote:
> On Thu, Oct 03, 2013 at 02:44:53PM +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 <sebastian.hesselbarth@gmail.com>
> > ---
> > - Added Benjamin and Grant who where part of the discussion last time
> >   and gave valuable input on DT fixups.
> > - Patches are based on v3.12-rc1 and depend on latest mv643xx_eth
> >   fixes applied yesterday by David Miller [1].
> > [1] 
> https://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=569943d0639c85a451ea853087cbd5f738247dd9
> > Cc: Jason Cooper <jason@lakedaemon.net>
> > Cc: Andrew Lunn <andrew@lunn.ch>
> > Cc: Russell King <linux@arm.linux.org.uk>
> > Cc: Grant Likely <grant.likely@linaro.org>
> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
> > Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> > Cc: linux-arm-kernel@lists.infradead.org
> > Cc: linux-kernel@vger.kernel.org
> > ---
> >  arch/arm/mach-kirkwood/board-dt.c |   72 
> +++++++++++++++++++++++++++++++++++--
> >  1 file changed, 69 insertions(+), 3 deletions(-)
> > diff --git a/arch/arm/mach-kirkwood/board-dt.c 
> b/arch/arm/mach-kirkwood/board-dt.c
> > index 82d3ad8..a2974ad 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 +68,71 @@ 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 property *pmac;
> > +		void __iomem *io;
> > +		u8 *macaddr;
> > +		u32 reg;
> > +
> > +		if (!pnp || !of_device_is_available(pnp))
> > +			continue;
> > +
> > +		if (of_get_mac_address(np))
> > +			continue;
> > +
> > +		pr_err(FW_BUG "%s: local-mac-address is not set\n",
> > +		       np->full_name);
> > +
> > +		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;
>
> Hi Sebastian
>
> What happens if at this point, the ethernet clock is gated off?  I
> assume the CPU locks solid, requiring a power cycle.
>
> It would be a bit of an odd situation, u-boot has disabled the clock,
> yet we have a DT node for the device and no valid local-mac-address.
> We do however know that Jason Gunthorpe u-boot does gate the second
> ethernet for his board, so it is not completely impossible to hit this
> situation, particularly when bringing up a new board.
>
> Are we too early in the boot to actually use the clock information in
> the node to find it, and clk_prepare_enable() it before making the
> access?

Ccframework is up when calling this. I suggest to call clk_is_enabled and 
also skip the fixup if it isn't. Clk_prepare_enable ist quite useless, as 
register contents will suffer what this workaround is about. I send an 
updated v2 later but someone will have to test as I don't have kirkwood 
around till next week.

> 	Andrew
diff mbox

Patch

diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
index 82d3ad8..a2974ad 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 +68,71 @@  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 property *pmac;
+		void __iomem *io;
+		u8 *macaddr;
+		u32 reg;
+
+		if (!pnp || !of_device_is_available(pnp))
+			continue;
+
+		if (of_get_mac_address(np))
+			continue;
+
+		pr_err(FW_BUG "%s: local-mac-address is not set\n",
+		       np->full_name);
+
+		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 +164,10 @@  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;