ixgbe: Add support for entering low power link up state

When the device is closing or suspending, call ixgbe_enter_lplu to
enter low power link up state on devices that support it. When this
is done, prevent the phy from being reset in the ixgbe_down path
so that link is present when calling ixgbe_enter_lplu.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 143 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c
index 662d2e896286..bbc5a2da86c4 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c
@@ -1458,6 +1458,144 @@ static s32 ixgbe_reset_phy_t_X550em(struct ixgbe_hw *hw)
 	return ixgbe_enable_lasi_ext_t_x550em(hw);
 }
 
+/** ixgbe_get_lcd_x550em - Determine lowest common denominator
+ *  @hw: pointer to hardware structure
+ *  @lcd_speed: pointer to lowest common link speed
+ *
+ *  Determine lowest common link speed with link partner.
+ **/
+static s32 ixgbe_get_lcd_t_x550em(struct ixgbe_hw *hw,
+				  ixgbe_link_speed *lcd_speed)
+{
+	u16 an_lp_status;
+	s32 status;
+	u16 word = hw->eeprom.ctrl_word_3;
+
+	*lcd_speed = IXGBE_LINK_SPEED_UNKNOWN;
+
+	status = hw->phy.ops.read_reg(hw, IXGBE_AUTO_NEG_LP_STATUS,
+				      IXGBE_MDIO_AUTO_NEG_DEV_TYPE,
+				      &an_lp_status);
+	if (status)
+		return status;
+
+	/* If link partner advertised 1G, return 1G */
+	if (an_lp_status & IXGBE_AUTO_NEG_LP_1000BASE_CAP) {
+		*lcd_speed = IXGBE_LINK_SPEED_1GB_FULL;
+		return status;
+	}
+
+	/* If 10G disabled for LPLU via NVM D10GMP, then return no valid LCD */
+	if ((hw->bus.lan_id && (word & NVM_INIT_CTRL_3_D10GMP_PORT1)) ||
+	    (word & NVM_INIT_CTRL_3_D10GMP_PORT0))
+		return status;
+
+	/* Link partner not capable of lower speeds, return 10G */
+	*lcd_speed = IXGBE_LINK_SPEED_10GB_FULL;
+	return status;
+}
+
+/** ixgbe_enter_lplu_x550em - Transition to low power states
+ *  @hw: pointer to hardware structure
+ *
+ *  Configures Low Power Link Up on transition to low power states
+ *  (from D0 to non-D0). Link is required to enter LPLU so avoid resetting
+ *  the X557 PHY immediately prior to entering LPLU.
+ **/
+static s32 ixgbe_enter_lplu_t_x550em(struct ixgbe_hw *hw)
+{
+	u16 an_10g_cntl_reg, autoneg_reg, speed;
+	s32 status;
+	ixgbe_link_speed lcd_speed;
+	u32 save_autoneg;
+	bool link_up;
+
+	/* SW LPLU not required on later HW revisions. */
+	if (IXGBE_FUSES0_REV1 & IXGBE_READ_REG(hw, IXGBE_FUSES0_GROUP(0)))
+		return 0;
+
+	/* If blocked by MNG FW, then don't restart AN */
+	if (ixgbe_check_reset_blocked(hw))
+		return 0;
+
+	status = ixgbe_ext_phy_t_x550em_get_link(hw, &link_up);
+	if (status)
+		return status;
+
+	status = hw->eeprom.ops.read(hw, NVM_INIT_CTRL_3,
+				     &hw->eeprom.ctrl_word_3);
+	if (status)
+		return status;
+
+	/* If link is down, LPLU disabled in NVM, WoL disabled, or
+	 * manageability disabled, then force link down by entering
+	 * low power mode.
+	 */
+	if (!link_up || !(hw->eeprom.ctrl_word_3 & NVM_INIT_CTRL_3_LPLU) ||
+	    !(hw->wol_enabled || ixgbe_mng_present(hw)))
+		return ixgbe_set_copper_phy_power(hw, false);
+
+	/* Determine LCD */
+	status = ixgbe_get_lcd_t_x550em(hw, &lcd_speed);
+	if (status)
+		return status;
+
+	/* If no valid LCD link speed, then force link down and exit. */
+	if (lcd_speed == IXGBE_LINK_SPEED_UNKNOWN)
+		return ixgbe_set_copper_phy_power(hw, false);
+
+	status = hw->phy.ops.read_reg(hw, IXGBE_MDIO_AUTO_NEG_VENDOR_STAT,
+				      IXGBE_MDIO_AUTO_NEG_DEV_TYPE,
+				      &speed);
+	if (status)
+		return status;
+
+	/* If no link now, speed is invalid so take link down */
+	status = ixgbe_ext_phy_t_x550em_get_link(hw, &link_up);
+	if (status)
+		return ixgbe_set_copper_phy_power(hw, false);
+
+	/* clear everything but the speed bits */
+	speed &= IXGBE_MDIO_AUTO_NEG_VEN_STAT_SPEED_MASK;
+
+	/* If current speed is already LCD, then exit. */
+	if (((speed == IXGBE_MDIO_AUTO_NEG_VENDOR_STATUS_1GB) &&
+	     (lcd_speed == IXGBE_LINK_SPEED_1GB_FULL)) ||
+	    ((speed == IXGBE_MDIO_AUTO_NEG_VENDOR_STATUS_10GB) &&
+	     (lcd_speed == IXGBE_LINK_SPEED_10GB_FULL)))
+		return status;
+
+	/* Clear AN completed indication */
+	status = hw->phy.ops.read_reg(hw, IXGBE_MDIO_AUTO_NEG_VENDOR_TX_ALARM,
+				      IXGBE_MDIO_AUTO_NEG_DEV_TYPE,
+				      &autoneg_reg);
+	if (status)
+		return status;
+
+	status = hw->phy.ops.read_reg(hw, IXGBE_MII_10GBASE_T_AUTONEG_CTRL_REG,
+				      IXGBE_MDIO_AUTO_NEG_DEV_TYPE,
+				      &an_10g_cntl_reg);
+	if (status)
+		return status;
+
+	status = hw->phy.ops.read_reg(hw,
+				      IXGBE_MII_AUTONEG_VENDOR_PROVISION_1_REG,
+				      IXGBE_MDIO_AUTO_NEG_DEV_TYPE,
+				      &autoneg_reg);
+	if (status)
+		return status;
+
+	save_autoneg = hw->phy.autoneg_advertised;
+
+	/* Setup link at least common link speed */
+	status = hw->mac.ops.setup_link(hw, lcd_speed, false);
+
+	/* restore autoneg from before setting lplu speed */
+	hw->phy.autoneg_advertised = save_autoneg;
+
+	return status;
+}
+
 /** ixgbe_init_phy_ops_X550em - PHY/SFP specific init
  *  @hw: pointer to hardware structure
  *
@@ -1528,6 +1666,11 @@ static s32 ixgbe_init_phy_ops_X550em(struct ixgbe_hw *hw)
 			ret_val = ixgbe_setup_kr_speed_x550em(hw, speed);
 		}
 
+		/* setup SW LPLU only for first revision */
+		if (!(IXGBE_FUSES0_REV1 & IXGBE_READ_REG(hw,
+							IXGBE_FUSES0_GROUP(0))))
+			phy->ops.enter_lplu = ixgbe_enter_lplu_t_x550em;
+
 		phy->ops.handle_lasi = ixgbe_handle_lasi_ext_t_x550em;
 		phy->ops.reset = ixgbe_reset_phy_t_X550em;
 		break;