--- /dev/null
+From 7f36ac946bfbd4090b8b94be3661b41ac73e21f4 Mon Sep 17 00:00:00 2001
+From: Russell King <rmk+kernel@arm.linux.org.uk>
+Date: Fri, 25 Sep 2015 17:43:52 +0100
+Subject: [PATCH 717/744] phy: add I2C mdio bus
+
+Add an I2C MDIO bus bridge library, to allow phylib to access PHYs which
+are connected to an I2C bus instead of the more conventional MDIO bus.
+Such PHYs can be found in SFP adapters and SFF modules.
+
+Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
+---
+ drivers/net/phy/Kconfig | 10 ++++++
+ drivers/net/phy/Makefile | 1 +
+ drivers/net/phy/mdio-i2c.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++
+ drivers/net/phy/mdio-i2c.h | 19 ++++++++++
+ 4 files changed, 120 insertions(+)
+ create mode 100644 drivers/net/phy/mdio-i2c.c
+ create mode 100644 drivers/net/phy/mdio-i2c.h
+
+--- a/drivers/net/phy/Kconfig
++++ b/drivers/net/phy/Kconfig
+@@ -233,6 +233,16 @@ config MDIO_GPIO
+ To compile this driver as a module, choose M here: the module
+ will be called mdio-gpio.
+
++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_OCTEON
+ tristate "Support for MDIO buses on Octeon and ThunderX SOCs"
+ depends on 64BIT
+--- a/drivers/net/phy/Makefile
++++ b/drivers/net/phy/Makefile
+@@ -41,6 +41,7 @@ obj-$(CONFIG_SWCONFIG_B53) += b53/
+ obj-$(CONFIG_FIXED_PHY) += fixed_phy.o
+ obj-$(CONFIG_MDIO_BITBANG) += mdio-bitbang.o
+ obj-$(CONFIG_MDIO_GPIO) += mdio-gpio.o
++obj-$(CONFIG_MDIO_I2C) += mdio-i2c.o
+ obj-$(CONFIG_NATIONAL_PHY) += national.o
+ obj-$(CONFIG_DP83640_PHY) += dp83640.o
+ obj-$(CONFIG_DP83848_PHY) += dp83848.o
+--- /dev/null
++++ b/drivers/net/phy/mdio-i2c.c
+@@ -0,0 +1,90 @@
++/*
++ * 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.
++ */
++#include <linux/i2c.h>
++#include <linux/phy.h>
++
++#include "mdio-i2c.h"
++
++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;
++
++ bus_addr = 0x40 + phy_id;
++ if (bus_addr == 0x50 || bus_addr == 0x51)
++ return 0xffff;
++
++ 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 bus_addr, ret;
++ u8 data[3];
++
++ bus_addr = 0x40 + phy_id;
++ if (bus_addr == 0x50 || bus_addr == 0x51)
++ return 0;
++
++ data[0] = reg;
++ data[1] = val >> 8;
++ data[2] = val;
++
++ msg.addr = bus_addr;
++ 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");
+--- /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
projects / openwrt / openwrt.git / blobdiff