[Intel-wired-lan] [PATCH] [iwl-net] igc: write to phy power management and management control registers to power up/power down the phy during interface up/down

[Prasad Koya]

 For I225/226 parts, when the interface is set down with "ip
 link set <dev> down", interface is down but the PHY (led) continues
 to be up. This patch makes the phy to be actually off/on during
 interface down/up events.

Signed-off-by: Prasad Koya <prasad at arista.com>
---
 drivers/net/ethernet/intel/igc/igc_defines.h |  3 ++
 drivers/net/ethernet/intel/igc/igc_phy.c     | 42 +++++++++++++-------
 2 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index b3037016f31d..6f60f5bd9cc7 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -684,4 +684,7 @@
 #define IGC_LTRMAXV_LSNP_REQ		0x00008000 /* LTR Snoop Requirement */
 #define IGC_LTRMAXV_SCALE_SHIFT		10
 
+/* PHY Power management register */
+#define IGC_GO_LINK_DISCONNECT		0x0020	   /* Go Link Disconnect */
+
 #endif /* _IGC_DEFINES_H_ */
diff --git a/drivers/net/ethernet/intel/igc/igc_phy.c b/drivers/net/ethernet/intel/igc/igc_phy.c
index 53b77c969c85..319cdf876f4e 100644
--- a/drivers/net/ethernet/intel/igc/igc_phy.c
+++ b/drivers/net/ethernet/intel/igc/igc_phy.c
@@ -107,12 +107,22 @@ s32 igc_phy_has_link(struct igc_hw *hw, u32 iterations,
  */
 void igc_power_up_phy_copper(struct igc_hw *hw)
 {
-	u16 mii_reg = 0;
+	struct igc_phy_info *phy = &hw->phy;
+	u32 phpm, manc;
+
+	if (phy->ops.acquire(hw))
+		return;
+
+	manc = rd32(IGC_MANC);
+	manc &= ~IGC_MANC_BLK_PHY_RST_ON_IDE;
+	wr32(IGC_MANC, manc);
 
-	/* The PHY will retain its settings across a power down/up cycle */
-	hw->phy.ops.read_reg(hw, PHY_CONTROL, &mii_reg);
-	mii_reg &= ~MII_CR_POWER_DOWN;
-	hw->phy.ops.write_reg(hw, PHY_CONTROL, mii_reg);
+	phpm = rd32(IGC_I225_PHPM);
+	phpm &= ~IGC_GO_LINK_DISCONNECT;
+	wr32(IGC_I225_PHPM, phpm);
+	usleep_range(100, 200);
+
+	hw->phy.ops.release(hw);
 }
 
 /**
@@ -124,17 +134,21 @@ void igc_power_up_phy_copper(struct igc_hw *hw)
  */
 void igc_power_down_phy_copper(struct igc_hw *hw)
 {
-	u16 mii_reg = 0;
-
-	/* The PHY will retain its settings across a power down/up cycle */
-	hw->phy.ops.read_reg(hw, PHY_CONTROL, &mii_reg);
-	mii_reg |= MII_CR_POWER_DOWN;
+	struct igc_phy_info *phy = &hw->phy;
+	u32 phpm, manc;
 
-	/* Temporary workaround - should be removed when PHY will implement
-	 * IEEE registers as properly
-	 */
-	/* hw->phy.ops.write_reg(hw, PHY_CONTROL, mii_reg);*/
+	if (phy->ops.acquire(hw))
+		return;
+	/* Set "Go Link Disconnect" bit in the PHPM register to turn off the PHY */
+	phpm = rd32(IGC_I225_PHPM);
+	phpm |= IGC_GO_LINK_DISCONNECT;
+	wr32(IGC_I225_PHPM, phpm);
 	usleep_range(1000, 2000);
+
+	manc = rd32(IGC_MANC);
+	wr32(IGC_MANC, manc | IGC_MANC_BLK_PHY_RST_ON_IDE);
+
+	phy->ops.release(hw);
 }
 
 /**
-- 
2.25.1