9217e566bd
It's common practice to store MAC addresses for network interfaces into nvmem devices. However the code to actually do this in the kernel lacks, so this patch adds of_get_nvmem_mac_address() for drivers to obtain the address from an nvmem cell provider. This is particulary useful on devices where the ethernet interface cannot be configured by the bootloader, for example because it's in an FPGA. Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
123 lines
3.3 KiB
C
123 lines
3.3 KiB
C
/*
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* OF helpers for network devices.
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*
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* This file is released under the GPLv2
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*
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* Initially copied out of arch/powerpc/kernel/prom_parse.c
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*/
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#include <linux/etherdevice.h>
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#include <linux/kernel.h>
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#include <linux/nvmem-consumer.h>
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#include <linux/of_net.h>
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#include <linux/phy.h>
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#include <linux/export.h>
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/**
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* of_get_phy_mode - Get phy mode for given device_node
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* @np: Pointer to the given device_node
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*
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* The function gets phy interface string from property 'phy-mode' or
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* 'phy-connection-type', and return its index in phy_modes table, or errno in
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* error case.
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*/
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int of_get_phy_mode(struct device_node *np)
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{
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const char *pm;
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int err, i;
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err = of_property_read_string(np, "phy-mode", &pm);
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if (err < 0)
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err = of_property_read_string(np, "phy-connection-type", &pm);
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if (err < 0)
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return err;
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for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
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if (!strcasecmp(pm, phy_modes(i)))
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return i;
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return -ENODEV;
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}
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EXPORT_SYMBOL_GPL(of_get_phy_mode);
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static const void *of_get_mac_addr(struct device_node *np, const char *name)
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{
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struct property *pp = of_find_property(np, name, NULL);
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if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
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return pp->value;
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return NULL;
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}
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/**
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* Search the device tree for the best MAC address to use. 'mac-address' is
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* checked first, because that is supposed to contain to "most recent" MAC
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* address. If that isn't set, then 'local-mac-address' is checked next,
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* because that is the default address. If that isn't set, then the obsolete
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* 'address' is checked, just in case we're using an old device tree.
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*
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* Note that the 'address' property is supposed to contain a virtual address of
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* the register set, but some DTS files have redefined that property to be the
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* MAC address.
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*
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* All-zero MAC addresses are rejected, because those could be properties that
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* exist in the device tree, but were not set by U-Boot. For example, the
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* DTS could define 'mac-address' and 'local-mac-address', with zero MAC
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* addresses. Some older U-Boots only initialized 'local-mac-address'. In
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* this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
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* but is all zeros.
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*/
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const void *of_get_mac_address(struct device_node *np)
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{
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const void *addr;
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addr = of_get_mac_addr(np, "mac-address");
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if (addr)
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return addr;
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addr = of_get_mac_addr(np, "local-mac-address");
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if (addr)
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return addr;
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return of_get_mac_addr(np, "address");
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}
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EXPORT_SYMBOL(of_get_mac_address);
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/**
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* Obtain the MAC address from an nvmem provider named 'mac-address' through
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* device tree.
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* On success, copies the new address into memory pointed to by addr and
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* returns 0. Returns a negative error code otherwise.
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* @np: Device tree node containing the nvmem-cells phandle
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* @addr: Pointer to receive the MAC address using ether_addr_copy()
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*/
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int of_get_nvmem_mac_address(struct device_node *np, void *addr)
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{
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struct nvmem_cell *cell;
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const void *mac;
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size_t len;
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int ret;
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cell = of_nvmem_cell_get(np, "mac-address");
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if (IS_ERR(cell))
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return PTR_ERR(cell);
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mac = nvmem_cell_read(cell, &len);
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nvmem_cell_put(cell);
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if (IS_ERR(mac))
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return PTR_ERR(mac);
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if (len < ETH_ALEN || !is_valid_ether_addr(mac)) {
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ret = -EINVAL;
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} else {
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ether_addr_copy(addr, mac);
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ret = 0;
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}
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kfree(mac);
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return ret;
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}
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EXPORT_SYMBOL(of_get_nvmem_mac_address);
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