diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig index 928fd892f167546e329f913ec10ea56e454cea0d..a1d6fdba8980f025989479715c88b8e1aa4f44ef 100644 --- a/drivers/net/phy/Kconfig +++ b/drivers/net/phy/Kconfig @@ -106,6 +106,16 @@ config MDIO_HISI_FEMAC This module provides a driver for the MDIO busses found in the Hisilicon SoC that have an Fast Ethernet MAC. +config MDIO_I2C + tristate + depends on I2C + help + Support I2C based PHYs. This provides a MDIO bus bridged + to I2C to allow PHYs connected in I2C mode to be accessed + using the existing infrastructure. + + This is library mode. + config MDIO_MOXART tristate "MOXA ART MDIO interface support" depends on ARCH_MOXART diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile index 8e9b9f34938445f798ad8248eec6eaee3728dc8b..113e8d525c5e798b0735ab93c18f03fcc82e3db2 100644 --- a/drivers/net/phy/Makefile +++ b/drivers/net/phy/Makefile @@ -30,6 +30,7 @@ obj-$(CONFIG_MDIO_BUS_MUX_MMIOREG) += mdio-mux-mmioreg.o obj-$(CONFIG_MDIO_CAVIUM) += mdio-cavium.o obj-$(CONFIG_MDIO_GPIO) += mdio-gpio.o obj-$(CONFIG_MDIO_HISI_FEMAC) += mdio-hisi-femac.o +obj-$(CONFIG_MDIO_I2C) += mdio-i2c.o obj-$(CONFIG_MDIO_MOXART) += mdio-moxart.o obj-$(CONFIG_MDIO_OCTEON) += mdio-octeon.o obj-$(CONFIG_MDIO_SUN4I) += mdio-sun4i.o diff --git a/drivers/net/phy/mdio-i2c.c b/drivers/net/phy/mdio-i2c.c new file mode 100644 index 0000000000000000000000000000000000000000..6d24fd13ca86e1cb80ef30a4d978a2447a4fd19c --- /dev/null +++ b/drivers/net/phy/mdio-i2c.c @@ -0,0 +1,109 @@ +/* + * MDIO I2C bridge + * + * Copyright (C) 2015-2016 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Network PHYs can appear on I2C buses when they are part of SFP module. + * This driver exposes these PHYs to the networking PHY code, allowing + * our PHY drivers access to these PHYs, and so allowing configuration + * of their settings. + */ +#include <linux/i2c.h> +#include <linux/phy.h> + +#include "mdio-i2c.h" + +/* + * I2C bus addresses 0x50 and 0x51 are normally an EEPROM, which is + * specified to be present in SFP modules. These correspond with PHY + * addresses 16 and 17. Disallow access to these "phy" addresses. + */ +static bool i2c_mii_valid_phy_id(int phy_id) +{ + return phy_id != 0x10 && phy_id != 0x11; +} + +static unsigned int i2c_mii_phy_addr(int phy_id) +{ + return phy_id + 0x40; +} + +static int i2c_mii_read(struct mii_bus *bus, int phy_id, int reg) +{ + struct i2c_adapter *i2c = bus->priv; + struct i2c_msg msgs[2]; + u8 data[2], dev_addr = reg; + int bus_addr, ret; + + if (!i2c_mii_valid_phy_id(phy_id)) + return 0xffff; + + bus_addr = i2c_mii_phy_addr(phy_id); + msgs[0].addr = bus_addr; + msgs[0].flags = 0; + msgs[0].len = 1; + msgs[0].buf = &dev_addr; + msgs[1].addr = bus_addr; + msgs[1].flags = I2C_M_RD; + msgs[1].len = sizeof(data); + msgs[1].buf = data; + + ret = i2c_transfer(i2c, msgs, ARRAY_SIZE(msgs)); + if (ret != ARRAY_SIZE(msgs)) + return 0xffff; + + return data[0] << 8 | data[1]; +} + +static int i2c_mii_write(struct mii_bus *bus, int phy_id, int reg, u16 val) +{ + struct i2c_adapter *i2c = bus->priv; + struct i2c_msg msg; + int ret; + u8 data[3]; + + if (!i2c_mii_valid_phy_id(phy_id)) + return 0; + + data[0] = reg; + data[1] = val >> 8; + data[2] = val; + + msg.addr = i2c_mii_phy_addr(phy_id); + msg.flags = 0; + msg.len = 3; + msg.buf = data; + + ret = i2c_transfer(i2c, &msg, 1); + + return ret < 0 ? ret : 0; +} + +struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c) +{ + struct mii_bus *mii; + + if (!i2c_check_functionality(i2c, I2C_FUNC_I2C)) + return ERR_PTR(-EINVAL); + + mii = mdiobus_alloc(); + if (!mii) + return ERR_PTR(-ENOMEM); + + snprintf(mii->id, MII_BUS_ID_SIZE, "i2c:%s", dev_name(parent)); + mii->parent = parent; + mii->read = i2c_mii_read; + mii->write = i2c_mii_write; + mii->priv = i2c; + + return mii; +} +EXPORT_SYMBOL_GPL(mdio_i2c_alloc); + +MODULE_AUTHOR("Russell King"); +MODULE_DESCRIPTION("MDIO I2C bridge library"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/net/phy/mdio-i2c.h b/drivers/net/phy/mdio-i2c.h new file mode 100644 index 0000000000000000000000000000000000000000..889ab57d7f3e856e22afaec7d70a9261fccc76d3 --- /dev/null +++ b/drivers/net/phy/mdio-i2c.h @@ -0,0 +1,19 @@ +/* + * MDIO I2C bridge + * + * Copyright (C) 2015 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#ifndef MDIO_I2C_H +#define MDIO_I2C_H + +struct device; +struct i2c_adapter; +struct mii_bus; + +struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c); + +#endif