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a9770eac51
Move all the MDIO drivers and multiplexers into drivers/net/mdio. The mdio core is however left in the phy directory, due to mutual dependencies between the MDIO core and the PHY core. Take this opportunity to sort the Kconfig based on the menuconfig strings, and move the multiplexers to the end with a separating comment. v2: Fix typo in commit message Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
118 lines
2.5 KiB
C
118 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* MDIO I2C bridge
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*
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* Copyright (C) 2015-2016 Russell King
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*
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* Network PHYs can appear on I2C buses when they are part of SFP module.
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* This driver exposes these PHYs to the networking PHY code, allowing
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* our PHY drivers access to these PHYs, and so allowing configuration
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* of their settings.
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*/
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#include <linux/i2c.h>
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#include <linux/mdio/mdio-i2c.h>
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#include <linux/phy.h>
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/*
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* I2C bus addresses 0x50 and 0x51 are normally an EEPROM, which is
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* specified to be present in SFP modules. These correspond with PHY
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* addresses 16 and 17. Disallow access to these "phy" addresses.
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*/
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static bool i2c_mii_valid_phy_id(int phy_id)
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{
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return phy_id != 0x10 && phy_id != 0x11;
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}
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static unsigned int i2c_mii_phy_addr(int phy_id)
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{
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return phy_id + 0x40;
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}
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static int i2c_mii_read(struct mii_bus *bus, int phy_id, int reg)
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{
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struct i2c_adapter *i2c = bus->priv;
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struct i2c_msg msgs[2];
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u8 addr[3], data[2], *p;
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int bus_addr, ret;
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if (!i2c_mii_valid_phy_id(phy_id))
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return 0xffff;
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p = addr;
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if (reg & MII_ADDR_C45) {
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*p++ = 0x20 | ((reg >> 16) & 31);
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*p++ = reg >> 8;
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}
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*p++ = reg;
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bus_addr = i2c_mii_phy_addr(phy_id);
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msgs[0].addr = bus_addr;
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msgs[0].flags = 0;
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msgs[0].len = p - addr;
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msgs[0].buf = addr;
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msgs[1].addr = bus_addr;
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msgs[1].flags = I2C_M_RD;
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msgs[1].len = sizeof(data);
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msgs[1].buf = data;
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ret = i2c_transfer(i2c, msgs, ARRAY_SIZE(msgs));
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if (ret != ARRAY_SIZE(msgs))
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return 0xffff;
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return data[0] << 8 | data[1];
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}
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static int i2c_mii_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
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{
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struct i2c_adapter *i2c = bus->priv;
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struct i2c_msg msg;
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int ret;
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u8 data[5], *p;
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if (!i2c_mii_valid_phy_id(phy_id))
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return 0;
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p = data;
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if (reg & MII_ADDR_C45) {
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*p++ = (reg >> 16) & 31;
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*p++ = reg >> 8;
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}
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*p++ = reg;
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*p++ = val >> 8;
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*p++ = val;
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msg.addr = i2c_mii_phy_addr(phy_id);
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msg.flags = 0;
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msg.len = p - data;
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msg.buf = data;
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ret = i2c_transfer(i2c, &msg, 1);
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return ret < 0 ? ret : 0;
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}
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struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c)
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{
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struct mii_bus *mii;
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if (!i2c_check_functionality(i2c, I2C_FUNC_I2C))
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return ERR_PTR(-EINVAL);
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mii = mdiobus_alloc();
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if (!mii)
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return ERR_PTR(-ENOMEM);
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snprintf(mii->id, MII_BUS_ID_SIZE, "i2c:%s", dev_name(parent));
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mii->parent = parent;
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mii->read = i2c_mii_read;
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mii->write = i2c_mii_write;
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mii->priv = i2c;
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return mii;
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}
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EXPORT_SYMBOL_GPL(mdio_i2c_alloc);
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MODULE_AUTHOR("Russell King");
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MODULE_DESCRIPTION("MDIO I2C bridge library");
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MODULE_LICENSE("GPL v2");
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