ixgbe: Add hardware specific initialization code for 82599 devices

This patch adds the hardware initialization code specific to 82599.  This
is similar to the 82598 hardware initialization code.  It also includes all
changes to the existing hardware init code to support 82599.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 576 insertions, 14 deletions

diff --git a/drivers/net/ixgbe/ixgbe_phy.c b/drivers/net/ixgbe/ixgbe_phy.c
index 77ec26f5650a..14e9606aa3b3 100644
--- a/drivers/net/ixgbe/ixgbe_phy.c
+++ b/drivers/net/ixgbe/ixgbe_phy.c
@@ -32,6 +32,18 @@
 #include "ixgbe_common.h"
 #include "ixgbe_phy.h"
 
+static void ixgbe_i2c_start(struct ixgbe_hw *hw);
+static void ixgbe_i2c_stop(struct ixgbe_hw *hw);
+static s32 ixgbe_clock_in_i2c_byte(struct ixgbe_hw *hw, u8 *data);
+static s32 ixgbe_clock_out_i2c_byte(struct ixgbe_hw *hw, u8 data);
+static s32 ixgbe_get_i2c_ack(struct ixgbe_hw *hw);
+static s32 ixgbe_clock_in_i2c_bit(struct ixgbe_hw *hw, bool *data);
+static s32 ixgbe_clock_out_i2c_bit(struct ixgbe_hw *hw, bool data);
+static s32 ixgbe_raise_i2c_clk(struct ixgbe_hw *hw, u32 *i2cctl);
+static void ixgbe_lower_i2c_clk(struct ixgbe_hw *hw, u32 *i2cctl);
+static s32 ixgbe_set_i2c_data(struct ixgbe_hw *hw, u32 *i2cctl, bool data);
+static bool ixgbe_get_i2c_data(u32 *i2cctl);
+static void ixgbe_i2c_bus_clear(struct ixgbe_hw *hw);
 static bool ixgbe_validate_phy_addr(struct ixgbe_hw *hw, u32 phy_addr);
 static enum ixgbe_phy_type ixgbe_get_phy_type_from_id(u32 phy_id);
 static s32 ixgbe_get_phy_id(struct ixgbe_hw *hw);
@@ -543,8 +555,9 @@ s32 ixgbe_identify_sfp_module_generic(struct ixgbe_hw *hw)
         u8 identifier = 0;
         u8 comp_codes_1g = 0;
         u8 comp_codes_10g = 0;
-        u8 oui_bytes[4] = {0, 0, 0, 0};
+        u8 oui_bytes[3] = {0, 0, 0};
         u8 transmission_media = 0;
+        u16 enforce_sfp = 0;
 
         status = hw->phy.ops.read_i2c_eeprom(hw, IXGBE_SFF_IDENTIFIER,
                                              &identifier);
@@ -564,18 +577,48 @@ s32 ixgbe_identify_sfp_module_generic(struct ixgbe_hw *hw)
 
                 /* ID Module
                  * =========
-                 * 0    SFP_DA_CU
-                 * 1    SFP_SR
-                 * 2    SFP_LR
+                 * 0    SFP_DA_CU
+                 * 1    SFP_SR
+                 * 2    SFP_LR
+                 * 3    SFP_DA_CORE0 - 82599-specific
+                 * 4    SFP_DA_CORE1 - 82599-specific
+                 * 5    SFP_SR/LR_CORE0 - 82599-specific
+                 * 6    SFP_SR/LR_CORE1 - 82599-specific
                  */
-                if (transmission_media & IXGBE_SFF_TWIN_AX_CAPABLE)
-                        hw->phy.sfp_type = ixgbe_sfp_type_da_cu;
-                else if (comp_codes_10g & IXGBE_SFF_10GBASESR_CAPABLE)
-                        hw->phy.sfp_type = ixgbe_sfp_type_sr;
-                else if (comp_codes_10g & IXGBE_SFF_10GBASELR_CAPABLE)
-                        hw->phy.sfp_type = ixgbe_sfp_type_lr;
-                else
-                        hw->phy.sfp_type = ixgbe_sfp_type_unknown;
+                if (hw->mac.type == ixgbe_mac_82598EB) {
+                        if (transmission_media & IXGBE_SFF_TWIN_AX_CAPABLE)
+                                hw->phy.sfp_type = ixgbe_sfp_type_da_cu;
+                        else if (comp_codes_10g & IXGBE_SFF_10GBASESR_CAPABLE)
+                                hw->phy.sfp_type = ixgbe_sfp_type_sr;
+                        else if (comp_codes_10g & IXGBE_SFF_10GBASELR_CAPABLE)
+                                hw->phy.sfp_type = ixgbe_sfp_type_lr;
+                        else
+                                hw->phy.sfp_type = ixgbe_sfp_type_unknown;
+                } else if (hw->mac.type == ixgbe_mac_82599EB) {
+                        if (transmission_media & IXGBE_SFF_TWIN_AX_CAPABLE)
+                                if (hw->bus.lan_id == 0)
+                                        hw->phy.sfp_type =
+                                                     ixgbe_sfp_type_da_cu_core0;
+                                else
+                                        hw->phy.sfp_type =
+                                                     ixgbe_sfp_type_da_cu_core1;
+                        else if (comp_codes_10g & IXGBE_SFF_10GBASESR_CAPABLE)
+                                if (hw->bus.lan_id == 0)
+                                        hw->phy.sfp_type =
+                                                      ixgbe_sfp_type_srlr_core0;
+                                else
+                                        hw->phy.sfp_type =
+                                                      ixgbe_sfp_type_srlr_core1;
+                        else if (comp_codes_10g & IXGBE_SFF_10GBASELR_CAPABLE)
+                                if (hw->bus.lan_id == 0)
+                                        hw->phy.sfp_type =
+                                                      ixgbe_sfp_type_srlr_core0;
+                                else
+                                        hw->phy.sfp_type =
+                                                      ixgbe_sfp_type_srlr_core1;
+                        else
+                                hw->phy.sfp_type = ixgbe_sfp_type_unknown;
+                }
 
                 /* Determine PHY vendor */
                 if (hw->phy.type == ixgbe_phy_unknown) {
@@ -607,6 +650,9 @@ s32 ixgbe_identify_sfp_module_generic(struct ixgbe_hw *hw)
                         case IXGBE_SFF_VENDOR_OUI_AVAGO:
                                 hw->phy.type = ixgbe_phy_sfp_avago;
                                 break;
+                        case IXGBE_SFF_VENDOR_OUI_INTEL:
+                                hw->phy.type = ixgbe_phy_sfp_intel;
+                                break;
                         default:
                                 if (transmission_media &
                                     IXGBE_SFF_TWIN_AX_CAPABLE)
@@ -616,7 +662,28 @@ s32 ixgbe_identify_sfp_module_generic(struct ixgbe_hw *hw)
                                 break;
                         }
                 }
-                status = 0;
+                if (hw->mac.type == ixgbe_mac_82598EB ||
+                    (hw->phy.sfp_type != ixgbe_sfp_type_sr &&
+                     hw->phy.sfp_type != ixgbe_sfp_type_lr &&
+                     hw->phy.sfp_type != ixgbe_sfp_type_srlr_core0 &&
+                     hw->phy.sfp_type != ixgbe_sfp_type_srlr_core1)) {
+                        status = 0;
+                        goto out;
+                }
+
+                hw->eeprom.ops.read(hw, IXGBE_PHY_ENFORCE_INTEL_SFP_OFFSET,
+                                    &enforce_sfp);
+                if (!(enforce_sfp & IXGBE_PHY_ALLOW_ANY_SFP)) {
+                        /* Make sure we're a supported PHY type */
+                        if (hw->phy.type == ixgbe_phy_sfp_intel) {
+                                status = 0;
+                        } else {
+                                hw_dbg(hw, "SFP+ module not supported\n");
+                                status = IXGBE_ERR_SFP_NOT_SUPPORTED;
+                        }
+                } else {
+                        status = 0;
+                }
         }
 
 out:
@@ -651,7 +718,7 @@ s32 ixgbe_get_sfp_init_sequence_offsets(struct ixgbe_hw *hw,
         hw->eeprom.ops.read(hw, IXGBE_PHY_INIT_OFFSET_NL, list_offset);
 
         if ((!*list_offset) || (*list_offset == 0xFFFF))
-                return IXGBE_ERR_PHY;
+                return IXGBE_ERR_SFP_NO_INIT_SEQ_PRESENT;
 
         /* Shift offset to first ID word */
         (*list_offset)++;
@@ -688,6 +755,501 @@ s32 ixgbe_get_sfp_init_sequence_offsets(struct ixgbe_hw *hw,
 }
 
 /**
+ *  ixgbe_read_i2c_eeprom_generic - Reads 8 bit EEPROM word over I2C interface
+ *  @hw: pointer to hardware structure
+ *  @byte_offset: EEPROM byte offset to read
+ *  @eeprom_data: value read
+ *
+ *  Performs byte read operation to SFP module's EEPROM over I2C interface.
+ **/
+s32 ixgbe_read_i2c_eeprom_generic(struct ixgbe_hw *hw, u8 byte_offset,
+                                  u8 *eeprom_data)
+{
+        return hw->phy.ops.read_i2c_byte(hw, byte_offset,
+                                         IXGBE_I2C_EEPROM_DEV_ADDR,
+                                         eeprom_data);
+}
+
+/**
+ *  ixgbe_write_i2c_eeprom_generic - Writes 8 bit EEPROM word over I2C interface
+ *  @hw: pointer to hardware structure
+ *  @byte_offset: EEPROM byte offset to write
+ *  @eeprom_data: value to write
+ *
+ *  Performs byte write operation to SFP module's EEPROM over I2C interface.
+ **/
+s32 ixgbe_write_i2c_eeprom_generic(struct ixgbe_hw *hw, u8 byte_offset,
+                                   u8 eeprom_data)
+{
+        return hw->phy.ops.write_i2c_byte(hw, byte_offset,
+                                          IXGBE_I2C_EEPROM_DEV_ADDR,
+                                          eeprom_data);
+}
+
+/**
+ *  ixgbe_read_i2c_byte_generic - Reads 8 bit word over I2C
+ *  @hw: pointer to hardware structure
+ *  @byte_offset: byte offset to read
+ *  @data: value read
+ *
+ *  Performs byte read operation to SFP module's EEPROM over I2C interface at
+ *  a specified deivce address.
+ **/
+s32 ixgbe_read_i2c_byte_generic(struct ixgbe_hw *hw, u8 byte_offset,
+                                u8 dev_addr, u8 *data)
+{
+        s32 status = 0;
+        u32 max_retry = 1;
+        u32 retry = 0;
+        bool nack = 1;
+
+        do {
+                ixgbe_i2c_start(hw);
+
+                /* Device Address and write indication */
+                status = ixgbe_clock_out_i2c_byte(hw, dev_addr);
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_get_i2c_ack(hw);
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_clock_out_i2c_byte(hw, byte_offset);
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_get_i2c_ack(hw);
+                if (status != 0)
+                        goto fail;
+
+                ixgbe_i2c_start(hw);
+
+                /* Device Address and read indication */
+                status = ixgbe_clock_out_i2c_byte(hw, (dev_addr | 0x1));
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_get_i2c_ack(hw);
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_clock_in_i2c_byte(hw, data);
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_clock_out_i2c_bit(hw, nack);
+                if (status != 0)
+                        goto fail;
+
+                ixgbe_i2c_stop(hw);
+                break;
+
+fail:
+                ixgbe_i2c_bus_clear(hw);
+                retry++;
+                if (retry < max_retry)
+                        hw_dbg(hw, "I2C byte read error - Retrying.\n");
+                else
+                        hw_dbg(hw, "I2C byte read error.\n");
+
+        } while (retry < max_retry);
+
+        return status;
+}
+
+/**
+ *  ixgbe_write_i2c_byte_generic - Writes 8 bit word over I2C
+ *  @hw: pointer to hardware structure
+ *  @byte_offset: byte offset to write
+ *  @data: value to write
+ *
+ *  Performs byte write operation to SFP module's EEPROM over I2C interface at
+ *  a specified device address.
+ **/
+s32 ixgbe_write_i2c_byte_generic(struct ixgbe_hw *hw, u8 byte_offset,
+                                 u8 dev_addr, u8 data)
+{
+        s32 status = 0;
+        u32 max_retry = 1;
+        u32 retry = 0;
+
+        do {
+                ixgbe_i2c_start(hw);
+
+                status = ixgbe_clock_out_i2c_byte(hw, dev_addr);
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_get_i2c_ack(hw);
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_clock_out_i2c_byte(hw, byte_offset);
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_get_i2c_ack(hw);
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_clock_out_i2c_byte(hw, data);
+                if (status != 0)
+                        goto fail;
+
+                status = ixgbe_get_i2c_ack(hw);
+                if (status != 0)
+                        goto fail;
+
+                ixgbe_i2c_stop(hw);
+                break;
+
+fail:
+                ixgbe_i2c_bus_clear(hw);
+                retry++;
+                if (retry < max_retry)
+                        hw_dbg(hw, "I2C byte write error - Retrying.\n");
+                else
+                        hw_dbg(hw, "I2C byte write error.\n");
+        } while (retry < max_retry);
+
+        return status;
+}
+
+/**
+ *  ixgbe_i2c_start - Sets I2C start condition
+ *  @hw: pointer to hardware structure
+ *
+ *  Sets I2C start condition (High -> Low on SDA while SCL is High)
+ **/
+static void ixgbe_i2c_start(struct ixgbe_hw *hw)
+{
+        u32 i2cctl = IXGBE_READ_REG(hw, IXGBE_I2CCTL);
+
+        /* Start condition must begin with data and clock high */
+        ixgbe_set_i2c_data(hw, &i2cctl, 1);
+        ixgbe_raise_i2c_clk(hw, &i2cctl);
+
+        /* Setup time for start condition (4.7us) */
+        udelay(IXGBE_I2C_T_SU_STA);
+
+        ixgbe_set_i2c_data(hw, &i2cctl, 0);
+
+        /* Hold time for start condition (4us) */
+        udelay(IXGBE_I2C_T_HD_STA);
+
+        ixgbe_lower_i2c_clk(hw, &i2cctl);
+
+        /* Minimum low period of clock is 4.7 us */
+        udelay(IXGBE_I2C_T_LOW);
+
+}
+
+/**
+ *  ixgbe_i2c_stop - Sets I2C stop condition
+ *  @hw: pointer to hardware structure
+ *
+ *  Sets I2C stop condition (Low -> High on SDA while SCL is High)
+ **/
+static void ixgbe_i2c_stop(struct ixgbe_hw *hw)
+{
+        u32 i2cctl = IXGBE_READ_REG(hw, IXGBE_I2CCTL);
+
+        /* Stop condition must begin with data low and clock high */
+        ixgbe_set_i2c_data(hw, &i2cctl, 0);
+        ixgbe_raise_i2c_clk(hw, &i2cctl);
+
+        /* Setup time for stop condition (4us) */
+        udelay(IXGBE_I2C_T_SU_STO);
+
+        ixgbe_set_i2c_data(hw, &i2cctl, 1);
+
+        /* bus free time between stop and start (4.7us)*/
+        udelay(IXGBE_I2C_T_BUF);
+}
+
+/**
+ *  ixgbe_clock_in_i2c_byte - Clocks in one byte via I2C
+ *  @hw: pointer to hardware structure
+ *  @data: data byte to clock in
+ *
+ *  Clocks in one byte data via I2C data/clock
+ **/
+static s32 ixgbe_clock_in_i2c_byte(struct ixgbe_hw *hw, u8 *data)
+{
+        s32 status = 0;
+        s32 i;
+        bool bit = 0;
+
+        for (i = 7; i >= 0; i--) {
+                status = ixgbe_clock_in_i2c_bit(hw, &bit);
+                *data |= bit << i;
+
+                if (status != 0)
+                        break;
+        }
+
+        return status;
+}
+
+/**
+ *  ixgbe_clock_out_i2c_byte - Clocks out one byte via I2C
+ *  @hw: pointer to hardware structure
+ *  @data: data byte clocked out
+ *
+ *  Clocks out one byte data via I2C data/clock
+ **/
+static s32 ixgbe_clock_out_i2c_byte(struct ixgbe_hw *hw, u8 data)
+{
+        s32 status = 0;
+        s32 i;
+        u32 i2cctl;
+        bool bit = 0;
+
+        for (i = 7; i >= 0; i--) {
+                bit = (data >> i) & 0x1;
+                status = ixgbe_clock_out_i2c_bit(hw, bit);
+
+                if (status != 0)
+                        break;
+        }
+
+        /* Release SDA line (set high) */
+        i2cctl = IXGBE_READ_REG(hw, IXGBE_I2CCTL);
+        i2cctl |= IXGBE_I2C_DATA_OUT;
+        IXGBE_WRITE_REG(hw, IXGBE_I2CCTL, i2cctl);
+
+        return status;
+}
+
+/**
+ *  ixgbe_get_i2c_ack - Polls for I2C ACK
+ *  @hw: pointer to hardware structure
+ *
+ *  Clocks in/out one bit via I2C data/clock
+ **/
+static s32 ixgbe_get_i2c_ack(struct ixgbe_hw *hw)
+{
+        s32 status;
+        u32 i = 0;
+        u32 i2cctl = IXGBE_READ_REG(hw, IXGBE_I2CCTL);
+        u32 timeout = 10;
+        bool ack = 1;
+
+        status = ixgbe_raise_i2c_clk(hw, &i2cctl);
+
+        if (status != 0)
+                goto out;
+
+        /* Minimum high period of clock is 4us */
+        udelay(IXGBE_I2C_T_HIGH);
+
+        /* Poll for ACK.  Note that ACK in I2C spec is
+         * transition from 1 to 0 */
+        for (i = 0; i < timeout; i++) {
+                i2cctl = IXGBE_READ_REG(hw, IXGBE_I2CCTL);
+                ack = ixgbe_get_i2c_data(&i2cctl);
+
+                udelay(1);
+                if (ack == 0)
+                        break;
+        }
+
+        if (ack == 1) {
+                hw_dbg(hw, "I2C ack was not received.\n");
+                status = IXGBE_ERR_I2C;
+        }
+
+        ixgbe_lower_i2c_clk(hw, &i2cctl);
+
+        /* Minimum low period of clock is 4.7 us */
+        udelay(IXGBE_I2C_T_LOW);
+
+out:
+        return status;
+}
+
+/**
+ *  ixgbe_clock_in_i2c_bit - Clocks in one bit via I2C data/clock
+ *  @hw: pointer to hardware structure
+ *  @data: read data value
+ *
+ *  Clocks in one bit via I2C data/clock
+ **/
+static s32 ixgbe_clock_in_i2c_bit(struct ixgbe_hw *hw, bool *data)
+{
+        s32 status;
+        u32 i2cctl = IXGBE_READ_REG(hw, IXGBE_I2CCTL);
+
+        status = ixgbe_raise_i2c_clk(hw, &i2cctl);
+
+        /* Minimum high period of clock is 4us */
+        udelay(IXGBE_I2C_T_HIGH);
+
+        i2cctl = IXGBE_READ_REG(hw, IXGBE_I2CCTL);
+        *data = ixgbe_get_i2c_data(&i2cctl);
+
+        ixgbe_lower_i2c_clk(hw, &i2cctl);
+
+        /* Minimum low period of clock is 4.7 us */
+        udelay(IXGBE_I2C_T_LOW);
+
+        return status;
+}
+
+/**
+ *  ixgbe_clock_out_i2c_bit - Clocks in/out one bit via I2C data/clock
+ *  @hw: pointer to hardware structure
+ *  @data: data value to write
+ *
+ *  Clocks out one bit via I2C data/clock
+ **/
+static s32 ixgbe_clock_out_i2c_bit(struct ixgbe_hw *hw, bool data)
+{
+        s32 status;
+        u32 i2cctl = IXGBE_READ_REG(hw, IXGBE_I2CCTL);
+
+        status = ixgbe_set_i2c_data(hw, &i2cctl, data);
+        if (status == 0) {
+                status = ixgbe_raise_i2c_clk(hw, &i2cctl);
+
+                /* Minimum high period of clock is 4us */
+                udelay(IXGBE_I2C_T_HIGH);
+
+                ixgbe_lower_i2c_clk(hw, &i2cctl);
+
+                /* Minimum low period of clock is 4.7 us.
+                 * This also takes care of the data hold time.
+                 */
+                udelay(IXGBE_I2C_T_LOW);
+        } else {
+                status = IXGBE_ERR_I2C;
+                hw_dbg(hw, "I2C data was not set to %X\n", data);
+        }
+
+        return status;
+}
+/**
+ *  ixgbe_raise_i2c_clk - Raises the I2C SCL clock
+ *  @hw: pointer to hardware structure
+ *  @i2cctl: Current value of I2CCTL register
+ *
+ *  Raises the I2C clock line '0'->'1'
+ **/
+static s32 ixgbe_raise_i2c_clk(struct ixgbe_hw *hw, u32 *i2cctl)
+{
+        s32 status = 0;
+
+        *i2cctl |= IXGBE_I2C_CLK_OUT;
+
+        IXGBE_WRITE_REG(hw, IXGBE_I2CCTL, *i2cctl);
+
+        /* SCL rise time (1000ns) */
+        udelay(IXGBE_I2C_T_RISE);
+
+        return status;
+}
+
+/**
+ *  ixgbe_lower_i2c_clk - Lowers the I2C SCL clock
+ *  @hw: pointer to hardware structure
+ *  @i2cctl: Current value of I2CCTL register
+ *
+ *  Lowers the I2C clock line '1'->'0'
+ **/
+static void ixgbe_lower_i2c_clk(struct ixgbe_hw *hw, u32 *i2cctl)
+{
+
+        *i2cctl &= ~IXGBE_I2C_CLK_OUT;
+
+        IXGBE_WRITE_REG(hw, IXGBE_I2CCTL, *i2cctl);
+
+        /* SCL fall time (300ns) */
+        udelay(IXGBE_I2C_T_FALL);
+}
+
+/**
+ *  ixgbe_set_i2c_data - Sets the I2C data bit
+ *  @hw: pointer to hardware structure
+ *  @i2cctl: Current value of I2CCTL register
+ *  @data: I2C data value (0 or 1) to set
+ *
+ *  Sets the I2C data bit
+ **/
+static s32 ixgbe_set_i2c_data(struct ixgbe_hw *hw, u32 *i2cctl, bool data)
+{
+        s32 status = 0;
+
+        if (data)
+                *i2cctl |= IXGBE_I2C_DATA_OUT;
+        else
+                *i2cctl &= ~IXGBE_I2C_DATA_OUT;
+
+        IXGBE_WRITE_REG(hw, IXGBE_I2CCTL, *i2cctl);
+
+        /* Data rise/fall (1000ns/300ns) and set-up time (250ns) */
+        udelay(IXGBE_I2C_T_RISE + IXGBE_I2C_T_FALL + IXGBE_I2C_T_SU_DATA);
+
+        /* Verify data was set correctly */
+        *i2cctl = IXGBE_READ_REG(hw, IXGBE_I2CCTL);
+        if (data != ixgbe_get_i2c_data(i2cctl)) {
+                status = IXGBE_ERR_I2C;
+                hw_dbg(hw, "Error - I2C data was not set to %X.\n", data);
+        }
+
+        return status;
+}
+
+/**
+ *  ixgbe_get_i2c_data - Reads the I2C SDA data bit
+ *  @hw: pointer to hardware structure
+ *  @i2cctl: Current value of I2CCTL register
+ *
+ *  Returns the I2C data bit value
+ **/
+static bool ixgbe_get_i2c_data(u32 *i2cctl)
+{
+        bool data;
+
+        if (*i2cctl & IXGBE_I2C_DATA_IN)
+                data = 1;
+        else
+                data = 0;
+
+        return data;
+}
+
+/**
+ *  ixgbe_i2c_bus_clear - Clears the I2C bus
+ *  @hw: pointer to hardware structure
+ *
+ *  Clears the I2C bus by sending nine clock pulses.
+ *  Used when data line is stuck low.
+ **/
+static void ixgbe_i2c_bus_clear(struct ixgbe_hw *hw)
+{
+        u32 i2cctl = IXGBE_READ_REG(hw, IXGBE_I2CCTL);
+        u32 i;
+
+        ixgbe_set_i2c_data(hw, &i2cctl, 1);
+
+        for (i = 0; i < 9; i++) {
+                ixgbe_raise_i2c_clk(hw, &i2cctl);
+
+                /* Min high period of clock is 4us */
+                udelay(IXGBE_I2C_T_HIGH);
+
+                ixgbe_lower_i2c_clk(hw, &i2cctl);
+
+                /* Min low period of clock is 4.7us*/
+                udelay(IXGBE_I2C_T_LOW);
+        }
+
+        /* Put the i2c bus back to default state */
+        ixgbe_i2c_stop(hw);
+}
+
+/**
  *  ixgbe_check_phy_link_tnx - Determine link and speed status
  *  @hw: pointer to hardware structure
  *