+/**
+ * ixgbe_device_supports_autoneg_fc - Check if phy supports autoneg flow
+ * control
+ * @hw: pointer to hardware structure
+ *
+ * There are several phys that do not support autoneg flow control. This
+ * function check the device id to see if the associated phy supports
+ * autoneg flow control.
+ **/
+static s32 ixgbe_device_supports_autoneg_fc(struct ixgbe_hw *hw)
+{
+
+ switch (hw->device_id) {
+ case IXGBE_DEV_ID_X540T:
+ return 0;
+ case IXGBE_DEV_ID_82599_T3_LOM:
+ return 0;
+ default:
+ return IXGBE_ERR_FC_NOT_SUPPORTED;
+ }
+}
+
+/**
+ * ixgbe_setup_fc - Set up flow control
+ * @hw: pointer to hardware structure
+ *
+ * Called at init time to set up flow control.
+ **/
+static s32 ixgbe_setup_fc(struct ixgbe_hw *hw)
+{
+ s32 ret_val = 0;
+ u32 reg = 0, reg_bp = 0;
+ u16 reg_cu = 0;
+
+ /*
+ * Validate the requested mode. Strict IEEE mode does not allow
+ * ixgbe_fc_rx_pause because it will cause us to fail at UNH.
+ */
+ if (hw->fc.strict_ieee && hw->fc.requested_mode == ixgbe_fc_rx_pause) {
+ hw_dbg(hw, "ixgbe_fc_rx_pause not valid in strict IEEE mode\n");
+ ret_val = IXGBE_ERR_INVALID_LINK_SETTINGS;
+ goto out;
+ }
+
+ /*
+ * 10gig parts do not have a word in the EEPROM to determine the
+ * default flow control setting, so we explicitly set it to full.
+ */
+ if (hw->fc.requested_mode == ixgbe_fc_default)
+ hw->fc.requested_mode = ixgbe_fc_full;
+
+ /*
+ * Set up the 1G and 10G flow control advertisement registers so the
+ * HW will be able to do fc autoneg once the cable is plugged in. If
+ * we link at 10G, the 1G advertisement is harmless and vice versa.
+ */
+ switch (hw->phy.media_type) {
+ case ixgbe_media_type_fiber:
+ case ixgbe_media_type_backplane:
+ reg = IXGBE_READ_REG(hw, IXGBE_PCS1GANA);
+ reg_bp = IXGBE_READ_REG(hw, IXGBE_AUTOC);
+ break;
+ case ixgbe_media_type_copper:
+ hw->phy.ops.read_reg(hw, MDIO_AN_ADVERTISE,
+ MDIO_MMD_AN, ®_cu);
+ break;
+ default:
+ break;
+ }
+
+ /*
+ * The possible values of fc.requested_mode are:
+ * 0: Flow control is completely disabled
+ * 1: Rx flow control is enabled (we can receive pause frames,
+ * but not send pause frames).
+ * 2: Tx flow control is enabled (we can send pause frames but
+ * we do not support receiving pause frames).
+ * 3: Both Rx and Tx flow control (symmetric) are enabled.
+ * other: Invalid.
+ */
+ switch (hw->fc.requested_mode) {
+ case ixgbe_fc_none:
+ /* Flow control completely disabled by software override. */
+ reg &= ~(IXGBE_PCS1GANA_SYM_PAUSE | IXGBE_PCS1GANA_ASM_PAUSE);
+ if (hw->phy.media_type == ixgbe_media_type_backplane)
+ reg_bp &= ~(IXGBE_AUTOC_SYM_PAUSE |
+ IXGBE_AUTOC_ASM_PAUSE);
+ else if (hw->phy.media_type == ixgbe_media_type_copper)
+ reg_cu &= ~(IXGBE_TAF_SYM_PAUSE | IXGBE_TAF_ASM_PAUSE);
+ break;
+ case ixgbe_fc_tx_pause:
+ /*
+ * Tx Flow control is enabled, and Rx Flow control is
+ * disabled by software override.
+ */
+ reg |= IXGBE_PCS1GANA_ASM_PAUSE;
+ reg &= ~IXGBE_PCS1GANA_SYM_PAUSE;
+ if (hw->phy.media_type == ixgbe_media_type_backplane) {
+ reg_bp |= IXGBE_AUTOC_ASM_PAUSE;
+ reg_bp &= ~IXGBE_AUTOC_SYM_PAUSE;
+ } else if (hw->phy.media_type == ixgbe_media_type_copper) {
+ reg_cu |= IXGBE_TAF_ASM_PAUSE;
+ reg_cu &= ~IXGBE_TAF_SYM_PAUSE;
+ }
+ break;
+ case ixgbe_fc_rx_pause:
+ /*
+ * Rx Flow control is enabled and Tx Flow control is
+ * disabled by software override. Since there really
+ * isn't a way to advertise that we are capable of RX
+ * Pause ONLY, we will advertise that we support both
+ * symmetric and asymmetric Rx PAUSE, as such we fall
+ * through to the fc_full statement. Later, we will
+ * disable the adapter's ability to send PAUSE frames.
+ */
+ case ixgbe_fc_full:
+ /* Flow control (both Rx and Tx) is enabled by SW override. */
+ reg |= IXGBE_PCS1GANA_SYM_PAUSE | IXGBE_PCS1GANA_ASM_PAUSE;
+ if (hw->phy.media_type == ixgbe_media_type_backplane)
+ reg_bp |= IXGBE_AUTOC_SYM_PAUSE |
+ IXGBE_AUTOC_ASM_PAUSE;
+ else if (hw->phy.media_type == ixgbe_media_type_copper)
+ reg_cu |= IXGBE_TAF_SYM_PAUSE | IXGBE_TAF_ASM_PAUSE;
+ break;
+ default:
+ hw_dbg(hw, "Flow control param set incorrectly\n");
+ ret_val = IXGBE_ERR_CONFIG;
+ goto out;
+ break;
+ }
+
+ if (hw->mac.type != ixgbe_mac_X540) {
+ /*
+ * Enable auto-negotiation between the MAC & PHY;
+ * the MAC will advertise clause 37 flow control.
+ */
+ IXGBE_WRITE_REG(hw, IXGBE_PCS1GANA, reg);
+ reg = IXGBE_READ_REG(hw, IXGBE_PCS1GLCTL);
+
+ /* Disable AN timeout */
+ if (hw->fc.strict_ieee)
+ reg &= ~IXGBE_PCS1GLCTL_AN_1G_TIMEOUT_EN;
+
+ IXGBE_WRITE_REG(hw, IXGBE_PCS1GLCTL, reg);
+ hw_dbg(hw, "Set up FC; PCS1GLCTL = 0x%08X\n", reg);
+ }
+
+ /*
+ * AUTOC restart handles negotiation of 1G and 10G on backplane
+ * and copper. There is no need to set the PCS1GCTL register.
+ *
+ */
+ if (hw->phy.media_type == ixgbe_media_type_backplane) {
+ reg_bp |= IXGBE_AUTOC_AN_RESTART;
+ IXGBE_WRITE_REG(hw, IXGBE_AUTOC, reg_bp);
+ } else if ((hw->phy.media_type == ixgbe_media_type_copper) &&
+ (ixgbe_device_supports_autoneg_fc(hw) == 0)) {
+ hw->phy.ops.write_reg(hw, MDIO_AN_ADVERTISE,
+ MDIO_MMD_AN, reg_cu);
+ }
+
+ hw_dbg(hw, "Set up FC; IXGBE_AUTOC = 0x%08X\n", reg);
+out:
+ return ret_val;
+}
+