igb: add locking to reads of the i2c interface

The current implementation of sgmii support isn't correctly locking the
interfaces for reads/writes.  This change pulls the read/write
functionality out of 82575.c and moves it to phy.c.  In addition it
replaces the implementation in 82575.c with one that uses locking around
the relocated i2c interface calls.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 97 insertions, 0 deletions

diff --git a/drivers/net/igb/e1000_phy.c b/drivers/net/igb/e1000_phy.c
index ee460600e74b..d4c928ccb294 100644
--- a/drivers/net/igb/e1000_phy.c
+++ b/drivers/net/igb/e1000_phy.c
@@ -239,6 +239,103 @@ out:
 }
 
 /**
+ *  igb_read_phy_reg_i2c - Read PHY register using i2c
+ *  @hw: pointer to the HW structure
+ *  @offset: register offset to be read
+ *  @data: pointer to the read data
+ *
+ *  Reads the PHY register at offset using the i2c interface and stores the
+ *  retrieved information in data.
+ **/
+s32 igb_read_phy_reg_i2c(struct e1000_hw *hw, u32 offset, u16 *data)
+{
+	struct e1000_phy_info *phy = &hw->phy;
+	u32 i, i2ccmd = 0;
+
+
+	/*
+	 * Set up Op-code, Phy Address, and register address in the I2CCMD
+	 * register.  The MAC will take care of interfacing with the
+	 * PHY to retrieve the desired data.
+	 */
+	i2ccmd = ((offset << E1000_I2CCMD_REG_ADDR_SHIFT) |
+	          (phy->addr << E1000_I2CCMD_PHY_ADDR_SHIFT) |
+	          (E1000_I2CCMD_OPCODE_READ));
+
+	wr32(E1000_I2CCMD, i2ccmd);
+
+	/* Poll the ready bit to see if the I2C read completed */
+	for (i = 0; i < E1000_I2CCMD_PHY_TIMEOUT; i++) {
+		udelay(50);
+		i2ccmd = rd32(E1000_I2CCMD);
+		if (i2ccmd & E1000_I2CCMD_READY)
+			break;
+	}
+	if (!(i2ccmd & E1000_I2CCMD_READY)) {
+		hw_dbg("I2CCMD Read did not complete\n");
+		return -E1000_ERR_PHY;
+	}
+	if (i2ccmd & E1000_I2CCMD_ERROR) {
+		hw_dbg("I2CCMD Error bit set\n");
+		return -E1000_ERR_PHY;
+	}
+
+	/* Need to byte-swap the 16-bit value. */
+	*data = ((i2ccmd >> 8) & 0x00FF) | ((i2ccmd << 8) & 0xFF00);
+
+	return 0;
+}
+
+/**
+ *  igb_write_phy_reg_i2c - Write PHY register using i2c
+ *  @hw: pointer to the HW structure
+ *  @offset: register offset to write to
+ *  @data: data to write at register offset
+ *
+ *  Writes the data to PHY register at the offset using the i2c interface.
+ **/
+s32 igb_write_phy_reg_i2c(struct e1000_hw *hw, u32 offset, u16 data)
+{
+	struct e1000_phy_info *phy = &hw->phy;
+	u32 i, i2ccmd = 0;
+	u16 phy_data_swapped;
+
+
+	/* Swap the data bytes for the I2C interface */
+	phy_data_swapped = ((data >> 8) & 0x00FF) | ((data << 8) & 0xFF00);
+
+	/*
+	 * Set up Op-code, Phy Address, and register address in the I2CCMD
+	 * register.  The MAC will take care of interfacing with the
+	 * PHY to retrieve the desired data.
+	 */
+	i2ccmd = ((offset << E1000_I2CCMD_REG_ADDR_SHIFT) |
+	          (phy->addr << E1000_I2CCMD_PHY_ADDR_SHIFT) |
+	          E1000_I2CCMD_OPCODE_WRITE |
+	          phy_data_swapped);
+
+	wr32(E1000_I2CCMD, i2ccmd);
+
+	/* Poll the ready bit to see if the I2C read completed */
+	for (i = 0; i < E1000_I2CCMD_PHY_TIMEOUT; i++) {
+		udelay(50);
+		i2ccmd = rd32(E1000_I2CCMD);
+		if (i2ccmd & E1000_I2CCMD_READY)
+			break;
+	}
+	if (!(i2ccmd & E1000_I2CCMD_READY)) {
+		hw_dbg("I2CCMD Write did not complete\n");
+		return -E1000_ERR_PHY;
+	}
+	if (i2ccmd & E1000_I2CCMD_ERROR) {
+		hw_dbg("I2CCMD Error bit set\n");
+		return -E1000_ERR_PHY;
+	}
+
+	return 0;
+}
+
+/**
  *  igb_read_phy_reg_igp - Read igp PHY register
  *  @hw: pointer to the HW structure
  *  @offset: register offset to be read