target/linux/generic/pending-4.19/745-net-mdio-i2c-add-support-for-Clause-45-accesses.patch

   1 From c9de73988a35c6c85810a992954ac568cca503e5 Mon Sep 17 00:00:00 2001
   2 From: Russell King <rmk+kernel@armlinux.org.uk>
   3 Date: Wed, 2 Oct 2019 10:31:10 +0100
   4 Subject: [PATCH 648/660] net: mdio-i2c: add support for Clause 45 accesses
   5
   6 Some SFP+ modules have PHYs on them just like SFP modules do, except
   7 they are Clause 45 PHYs.  The I2C protocol used to access them is
   8 modified slightly in order to send the device address and 16-bit
   9 register index.
  10
  11 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  12 ---
  13  drivers/net/phy/mdio-i2c.c | 28 ++++++++++++++++++++--------
  14  1 file changed, 20 insertions(+), 8 deletions(-)
  15
  16 --- a/drivers/net/phy/mdio-i2c.c
  17 +++ b/drivers/net/phy/mdio-i2c.c
  18 @@ -36,17 +36,24 @@ static int i2c_mii_read(struct mii_bus *
  19  {
  20         struct i2c_adapter *i2c = bus->priv;
  21         struct i2c_msg msgs[2];
  22 -       u8 data[2], dev_addr = reg;
  23 +       u8 addr[3], data[2], *p;
  24         int bus_addr, ret;
  25
  26         if (!i2c_mii_valid_phy_id(phy_id))
  27                 return 0xffff;
  28
  29 +       p = addr;
  30 +       if (reg & MII_ADDR_C45) {
  31 +               *p++ = 0x20 | ((reg >> 16) & 31);
  32 +               *p++ = reg >> 8;
  33 +       }
  34 +       *p++ = reg;
  35 +
  36         bus_addr = i2c_mii_phy_addr(phy_id);
  37         msgs[0].addr = bus_addr;
  38         msgs[0].flags = 0;
  39 -       msgs[0].len = 1;
  40 -       msgs[0].buf = &dev_addr;
  41 +       msgs[0].len = p - addr;
  42 +       msgs[0].buf = addr;
  43         msgs[1].addr = bus_addr;
  44         msgs[1].flags = I2C_M_RD;
  45         msgs[1].len = sizeof(data);
  46 @@ -64,18 +71,23 @@ static int i2c_mii_write(struct mii_bus
  47         struct i2c_adapter *i2c = bus->priv;
  48         struct i2c_msg msg;
  49         int ret;
  50 -       u8 data[3];
  51 +       u8 data[5], *p;
  52
  53         if (!i2c_mii_valid_phy_id(phy_id))
  54                 return 0;
  55
  56 -       data[0] = reg;
  57 -       data[1] = val >> 8;
  58 -       data[2] = val;
  59 +       p = data;
  60 +       if (reg & MII_ADDR_C45) {
  61 +               *p++ = (reg >> 16) & 31;
  62 +               *p++ = reg >> 8;
  63 +       }
  64 +       *p++ = reg;
  65 +       *p++ = val >> 8;
  66 +       *p++ = val;
  67
  68         msg.addr = i2c_mii_phy_addr(phy_id);
  69         msg.flags = 0;
  70 -       msg.len = 3;
  71 +       msg.len = p - data;
  72         msg.buf = data;
  73
  74         ret = i2c_transfer(i2c, &msg, 1);