target/linux/realtek/patches-5.15/711-net-phy-add-an-MDIO-SMBus-library.patch

   1 From d585c55b9f70cf9e8c66820d7efe7130c683f19e Mon Sep 17 00:00:00 2001
   2 From: Antoine Tenart <antoine.tenart@bootlin.com>
   3 Date: Fri, 21 Feb 2020 11:51:27 +0100
   4 Subject: [PATCH 2/3] net: phy: add an MDIO SMBus library
   5
   6 Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
   7 ---
   8  drivers/net/mdio/Kconfig      | 11 +++++++
   9  drivers/net/mdio/Makefile     |  1 +
  10  drivers/net/mdio/mdio-smbus.c | 62 +++++++++++++++++++++++++++++++++++
  11  drivers/net/phy/Kconfig       |  1 +
  12  include/linux/mdio/mdio-i2c.h | 16 +++++++++
  13  5 files changed, 91 insertions(+)
  14  create mode 100644 drivers/net/mdio/mdio-smbus.c
  15
  16 --- a/drivers/net/mdio/Kconfig
  17 +++ b/drivers/net/mdio/Kconfig
  18 @@ -40,6 +40,17 @@ config MDIO_SUN4I
  19           interface units of the Allwinner SoC that have an EMAC (A10,
  20           A12, A10s, etc.)
  21
  22 +config MDIO_SMBUS
  23 +       tristate
  24 +       depends on I2C_SMBUS
  25 +       help
  26 +         Support SMBus based PHYs. This provides a MDIO bus bridged
  27 +         to SMBus to allow PHYs connected in SMBus mode to be accessed
  28 +         using the existing infrastructure.
  29 +
  30 +         This is library mode.
  31 +
  32 +
  33  config MDIO_XGENE
  34         tristate "APM X-Gene SoC MDIO bus controller"
  35         depends on ARCH_XGENE || COMPILE_TEST
  36 --- a/drivers/net/mdio/Makefile
  37 +++ b/drivers/net/mdio/Makefile
  38 @@ -17,6 +17,7 @@ obj-$(CONFIG_MDIO_MOXART)             += mdio-moxar
  39  obj-$(CONFIG_MDIO_MSCC_MIIM)           += mdio-mscc-miim.o
  40  obj-$(CONFIG_MDIO_MVUSB)               += mdio-mvusb.o
  41  obj-$(CONFIG_MDIO_OCTEON)              += mdio-octeon.o
  42 +obj-$(CONFIG_MDIO_SMBUS)               += mdio-smbus.o
  43  obj-$(CONFIG_MDIO_SUN4I)               += mdio-sun4i.o
  44  obj-$(CONFIG_MDIO_THUNDER)             += mdio-thunder.o
  45  obj-$(CONFIG_MDIO_XGENE)               += mdio-xgene.o
  46 --- /dev/null
  47 +++ b/drivers/net/mdio/mdio-smbus.c
  48 @@ -0,0 +1,62 @@
  49 +// SPDX-License-Identifier: GPL-2.0-or-later
  50 +/*
  51 + * MDIO SMBus bridge
  52 + *
  53 + * Copyright (C) 2020 Antoine Tenart
  54 + *
  55 + * Network PHYs can appear on SMBus when they are part of SFP modules.
  56 + */
  57 +#include <linux/i2c.h>
  58 +#include <linux/phy.h>
  59 +#include <linux/mdio/mdio-i2c.h>
  60 +
  61 +static int smbus_mii_read(struct mii_bus *mii, int phy_id, int reg)
  62 +{
  63 +       struct i2c_adapter *i2c = mii->priv;
  64 +       union i2c_smbus_data data;
  65 +       int ret;
  66 +
  67 +       ret = i2c_smbus_xfer(i2c, i2c_mii_phy_addr(phy_id), 0, I2C_SMBUS_READ,
  68 +                            reg, I2C_SMBUS_BYTE_DATA, &data);
  69 +       if (ret < 0)
  70 +               return 0xff;
  71 +
  72 +       return data.byte;
  73 +}
  74 +
  75 +static int smbus_mii_write(struct mii_bus *mii, int phy_id, int reg, u16 val)
  76 +{
  77 +       struct i2c_adapter *i2c = mii->priv;
  78 +       union i2c_smbus_data data;
  79 +       int ret;
  80 +
  81 +       data.byte = val;
  82 +
  83 +       ret = i2c_smbus_xfer(i2c, i2c_mii_phy_addr(phy_id), 0, I2C_SMBUS_WRITE,
  84 +                            reg, I2C_SMBUS_BYTE_DATA, &data);
  85 +       return ret < 0 ? ret : 0;
  86 +}
  87 +
  88 +struct mii_bus *mdio_smbus_alloc(struct device *parent, struct i2c_adapter *i2c)
  89 +{
  90 +       struct mii_bus *mii;
  91 +
  92 +       if (!i2c_check_functionality(i2c, I2C_FUNC_SMBUS_BYTE_DATA))
  93 +               return ERR_PTR(-EINVAL);
  94 +
  95 +       mii = mdiobus_alloc();
  96 +       if (!mii)
  97 +               return ERR_PTR(-ENOMEM);
  98 +
  99 +       snprintf(mii->id, MII_BUS_ID_SIZE, "smbus:%s", dev_name(parent));
 100 +       mii->parent = parent;
 101 +       mii->read = smbus_mii_read;
 102 +       mii->write = smbus_mii_write;
 103 +       mii->priv = i2c;
 104 +
 105 +       return mii;
 106 +}
 107 +
 108 +MODULE_AUTHOR("Antoine Tenart");
 109 +MODULE_DESCRIPTION("MDIO SMBus bridge library");
 110 +MODULE_LICENSE("GPL");
 111 --- a/drivers/net/phy/Kconfig
 112 +++ b/drivers/net/phy/Kconfig
 113 @@ -60,6 +60,7 @@ config SFP
 114         depends on I2C && PHYLINK
 115         depends on HWMON || HWMON=n
 116         select MDIO_I2C
 117 +       select MDIO_SMBUS
 118
 119  comment "Switch configuration API + drivers"
 120
 121 --- a/include/linux/mdio/mdio-i2c.h
 122 +++ b/include/linux/mdio/mdio-i2c.h
 123 @@ -12,5 +12,21 @@ struct i2c_adapter;
 124  struct mii_bus;
 125
 126  struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c);
 127 +struct mii_bus *mdio_smbus_alloc(struct device *parent, struct i2c_adapter *i2c);
 128 +
 129 +/*
 130 + * I2C bus addresses 0x50 and 0x51 are normally an EEPROM, which is
 131 + * specified to be present in SFP modules.  These correspond with PHY
 132 + * addresses 16 and 17.  Disallow access to these "phy" addresses.
 133 + */
 134 +static bool i2c_mii_valid_phy_id(int phy_id)
 135 +{
 136 +       return phy_id != 0x10 && phy_id != 0x11;
 137 +}
 138 +
 139 +static unsigned int i2c_mii_phy_addr(int phy_id)
 140 +{
 141 +       return phy_id + 0x40;
 142 +}
 143
 144  #endif
 145 --- a/drivers/net/mdio/mdio-i2c.c
 146 +++ b/drivers/net/mdio/mdio-i2c.c
 147 @@ -13,21 +13,6 @@
 148  #include <linux/mdio/mdio-i2c.h>
 149  #include <linux/phy.h>
 150
 151 -/*
 152 - * I2C bus addresses 0x50 and 0x51 are normally an EEPROM, which is
 153 - * specified to be present in SFP modules.  These correspond with PHY
 154 - * addresses 16 and 17.  Disallow access to these "phy" addresses.
 155 - */
 156 -static bool i2c_mii_valid_phy_id(int phy_id)
 157 -{
 158 -       return phy_id != 0x10 && phy_id != 0x11;
 159 -}
 160 -
 161 -static unsigned int i2c_mii_phy_addr(int phy_id)
 162 -{
 163 -       return phy_id + 0x40;
 164 -}
 165 -
 166  static int i2c_mii_read(struct mii_bus *bus, int phy_id, int reg)
 167  {
 168         struct i2c_adapter *i2c = bus->priv;