OpenWrt – Rev 1
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From: John Crispin <blogic@openwrt.org>
Subject: NET: add mtd-mac-address support to of_get_mac_address()
Many embedded devices have information such as mac addresses stored inside mtd
devices. This patch allows us to add a property inside a node describing a
network interface. The new property points at a mtd partition with an offset
where the mac address can be found.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
drivers/of/of_net.c | 37 +++++++++++++++++++++++++++++++++++++
include/linux/of_net.h | 1 +
2 files changed, 38 insertions(+)
--- a/drivers/of/of_net.c
+++ b/drivers/of/of_net.c
@@ -10,6 +10,7 @@
#include <linux/of_net.h>
#include <linux/phy.h>
#include <linux/export.h>
+#include <linux/mtd/mtd.h>
/**
* of_get_phy_mode - Get phy mode for given device_node
@@ -38,7 +39,7 @@ int of_get_phy_mode(struct device_node *
}
EXPORT_SYMBOL_GPL(of_get_phy_mode);
-static const void *of_get_mac_addr(struct device_node *np, const char *name)
+static void *of_get_mac_addr(struct device_node *np, const char *name)
{
struct property *pp = of_find_property(np, name, NULL);
@@ -47,6 +48,79 @@ static const void *of_get_mac_addr(struc
return NULL;
}
+static const void *of_get_mac_address_mtd(struct device_node *np)
+{
+#ifdef CONFIG_MTD
+ struct device_node *mtd_np = NULL;
+ struct property *prop;
+ size_t retlen;
+ int size, ret;
+ struct mtd_info *mtd;
+ const char *part;
+ const __be32 *list;
+ phandle phandle;
+ u32 mac_inc = 0;
+ u8 mac[ETH_ALEN];
+ void *addr;
+ u32 inc_idx;
+
+ list = of_get_property(np, "mtd-mac-address", &size);
+ if (!list || (size != (2 * sizeof(*list))))
+ return NULL;
+
+ phandle = be32_to_cpup(list++);
+ if (phandle)
+ mtd_np = of_find_node_by_phandle(phandle);
+
+ if (!mtd_np)
+ return NULL;
+
+ part = of_get_property(mtd_np, "label", NULL);
+ if (!part)
+ part = mtd_np->name;
+
+ mtd = get_mtd_device_nm(part);
+ if (IS_ERR(mtd))
+ return NULL;
+
+ ret = mtd_read(mtd, be32_to_cpup(list), 6, &retlen, mac);
+ put_mtd_device(mtd);
+
+ if (of_property_read_u32(np, "mtd-mac-address-increment-byte", &inc_idx))
+ inc_idx = 5;
+ if (inc_idx > 5)
+ return NULL;
+
+ if (!of_property_read_u32(np, "mtd-mac-address-increment", &mac_inc))
+ mac[inc_idx] += mac_inc;
+
+ if (!is_valid_ether_addr(mac))
+ return NULL;
+
+ addr = of_get_mac_addr(np, "mac-address");
+ if (addr) {
+ memcpy(addr, mac, ETH_ALEN);
+ return addr;
+ }
+
+ prop = kzalloc(sizeof(*prop), GFP_KERNEL);
+ if (!prop)
+ return NULL;
+
+ prop->name = "mac-address";
+ prop->length = ETH_ALEN;
+ prop->value = kmemdup(mac, ETH_ALEN, GFP_KERNEL);
+ if (!prop->value || of_add_property(np, prop))
+ goto free;
+
+ return prop->value;
+free:
+ kfree(prop->value);
+ kfree(prop);
+#endif
+ return NULL;
+}
+
/**
* Search the device tree for the best MAC address to use. 'mac-address' is
* checked first, because that is supposed to contain to "most recent" MAC
@@ -64,11 +138,18 @@ static const void *of_get_mac_addr(struc
* addresses. Some older U-Boots only initialized 'local-mac-address'. In
* this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
* but is all zeros.
+ *
+ * If a mtd-mac-address property exists, try to fetch the MAC address from the
+ * specified mtd device, and store it as a 'mac-address' property
*/
const void *of_get_mac_address(struct device_node *np)
{
const void *addr;
+ addr = of_get_mac_address_mtd(np);
+ if (addr)
+ return addr;
+
addr = of_get_mac_addr(np, "mac-address");
if (addr)
return addr;