[PATCH 1/3] dt-bindings: nvmem: brcm,nvram: add #nvmem-cell-cells for MACs

[PATCH 1/3] dt-bindings: nvmem: brcm,nvram: add #nvmem-cell-cells for MACs

[Rafał Miłecki]

From: Rafał Miłecki <rafal@milecki.pl>

Broadcom's NVRAM contains MACs for Ethernet interfaces. Those MACs are
usually base addresses that are also used for calculating other MACs.

For example if a router vendor decided to use gmac0 it most likely
programmed NVRAM of each unit with a proper "et0macaddr" value. That is
a base.

Ethernet interface is usually connected to switch port. Switch usually
includes few LAN ports and a WAN port. MAC of WAN port gets calculated
as relative address to the interface one. Offset varies depending on
device model.

Wireless MACs may also need to be calculated using relevant offsets.

To support all those scenarios let MAC NVMEM cells be referenced with an
index specifying MAC offset.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
 .../devicetree/bindings/nvmem/brcm,nvram.yaml        | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml b/Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml
index 36def7128fca..a921e05cc544 100644
--- a/Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml
+++ b/Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml
@@ -36,14 +36,26 @@ properties:
   et0macaddr:
     type: object
     description: First Ethernet interface's MAC address
+    properties:
+      "#nvmem-cell-cells":
+        description: The first argument is a MAC address offset.
+        const: 1
 
   et1macaddr:
     type: object
     description: Second Ethernet interface's MAC address
+    properties:
+      "#nvmem-cell-cells":
+        description: The first argument is a MAC address offset.
+        const: 1
 
   et2macaddr:
     type: object
     description: Third Ethernet interface's MAC address
+    properties:
+      "#nvmem-cell-cells":
+        description: The first argument is a MAC address offset.
+        const: 1
 
 unevaluatedProperties: false
 
-- 
2.34.1

[PATCH 2/3] nvmem: brcm_nvram: add .read_post_process() for MACs

[Rafał Miłecki]

From: Rafał Miłecki <rafal@milecki.pl>

1. Parse ASCII MAC format into byte based
2. Calculate relative addresses based on index argument

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
 drivers/nvmem/Kconfig      |  1 +
 drivers/nvmem/brcm_nvram.c | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index b291b27048c7..688b70ba4826 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -55,6 +55,7 @@ config NVMEM_BRCM_NVRAM
 	tristate "Broadcom's NVRAM support"
 	depends on ARCH_BCM_5301X || COMPILE_TEST
 	depends on HAS_IOMEM
+	select GENERIC_NET_UTILS
 	help
 	  This driver provides support for Broadcom's NVRAM that can be accessed
 	  using I/O mapping.
diff --git a/drivers/nvmem/brcm_nvram.c b/drivers/nvmem/brcm_nvram.c
index 39aa27942f28..4567c597c87f 100644
--- a/drivers/nvmem/brcm_nvram.c
+++ b/drivers/nvmem/brcm_nvram.c
@@ -4,6 +4,8 @@
  */
 
 #include <linux/bcm47xx_nvram.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
 #include <linux/io.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
@@ -42,6 +44,25 @@ static int brcm_nvram_read(void *context, unsigned int offset, void *val,
 	return 0;
 }
 
+static int brcm_nvram_read_post_process_macaddr(void *context, const char *id, int index,
+						unsigned int offset, void *buf, size_t bytes)
+{
+	u8 mac[ETH_ALEN];
+
+	if (bytes != 3 * ETH_ALEN - 1)
+		return -EINVAL;
+
+	if (!mac_pton(buf, mac))
+		return -EINVAL;
+
+	if (index)
+		eth_addr_add(mac, index);
+
+	ether_addr_copy(buf, mac);
+
+	return 0;
+}
+
 static int brcm_nvram_add_cells(struct brcm_nvram *priv, uint8_t *data,
 				size_t len)
 {
@@ -75,6 +96,13 @@ static int brcm_nvram_add_cells(struct brcm_nvram *priv, uint8_t *data,
 		priv->cells[idx].offset = value - (char *)data;
 		priv->cells[idx].bytes = strlen(value);
 		priv->cells[idx].np = of_get_child_by_name(dev->of_node, priv->cells[idx].name);
+		if (!strcmp(var, "et0macaddr") ||
+		    !strcmp(var, "et1macaddr") ||
+		    !strcmp(var, "et2macaddr")) {
+			priv->cells[idx].raw_len = strlen(value);
+			priv->cells[idx].bytes = ETH_ALEN;
+			priv->cells[idx].read_post_process = brcm_nvram_read_post_process_macaddr;
+		}
 	}
 
 	return 0;
-- 
2.34.1

[PATCH 3/3] ARM: dts: BCM5301X: Specify WAN port MAC address for Luxul XWR-3150

[Rafał Miłecki]

From: Rafał Miłecki <rafal@milecki.pl>

It needs to be calculated based on the base Ethernet interface one.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
This PATCH is a proof of concept that can go separately through the ARM
DT tree. I'd actually suggest that. There are more .dts files I'll want
to update.
Srini: can you just take the first 2 patches from this series?
---
 arch/arm/boot/dts/bcm47094-luxul-xwr-3150-v1.dts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/bcm47094-luxul-xwr-3150-v1.dts b/arch/arm/boot/dts/bcm47094-luxul-xwr-3150-v1.dts
index 60a2c441d5bd..2dd05f4dce92 100644
--- a/arch/arm/boot/dts/bcm47094-luxul-xwr-3150-v1.dts
+++ b/arch/arm/boot/dts/bcm47094-luxul-xwr-3150-v1.dts
@@ -27,6 +27,7 @@ nvram@1eff0000 {
 		reg = <0x1eff0000 0x10000>;
 
 		et0macaddr: et0macaddr {
+			#nvmem-cell-cells = <1>;
 		};
 	};
 
@@ -76,7 +77,7 @@ button-restart {
 };
 
 &gmac0 {
-	nvmem-cells = <&et0macaddr>;
+	nvmem-cells = <&et0macaddr 0>;
 	nvmem-cell-names = "mac-address";
 };
 
@@ -119,6 +120,8 @@ port@3 {
 		port@4 {
 			reg = <4>;
 			label = "wan";
+			nvmem-cells = <&et0macaddr 5>;
+			nvmem-cell-names = "mac-address";
 		};
 
 		port@5 {
-- 
2.34.1

Re: [PATCH 1/3] dt-bindings: nvmem: brcm,nvram: add #nvmem-cell-cells for MACs

[Rob Herring]

On Thu, Apr 06, 2023 at 01:08:02PM +0200, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> Broadcom's NVRAM contains MACs for Ethernet interfaces. Those MACs are
> usually base addresses that are also used for calculating other MACs.
> 
> For example if a router vendor decided to use gmac0 it most likely
> programmed NVRAM of each unit with a proper "et0macaddr" value. That is
> a base.
> 
> Ethernet interface is usually connected to switch port. Switch usually
> includes few LAN ports and a WAN port. MAC of WAN port gets calculated
> as relative address to the interface one. Offset varies depending on
> device model.
> 
> Wireless MACs may also need to be calculated using relevant offsets.
> 
> To support all those scenarios let MAC NVMEM cells be referenced with an
> index specifying MAC offset.
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> ---
>  .../devicetree/bindings/nvmem/brcm,nvram.yaml        | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml b/Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml
> index 36def7128fca..a921e05cc544 100644
> --- a/Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/brcm,nvram.yaml
> @@ -36,14 +36,26 @@ properties:
>    et0macaddr:
>      type: object
>      description: First Ethernet interface's MAC address
> +    properties:
> +      "#nvmem-cell-cells":
> +        description: The first argument is a MAC address offset.
> +        const: 1

Not a new issue, but these nodes are missing 'additionalProperties: 
false'. Can you add that. With that,

Reviewed-by: Rob Herring <robh@kernel.org>