[PATCH net-next 1/7] net: stmmac: allow platforms to use PHY tx clock stop capability

["Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>]

Allow platform glue to instruct stmmac to make use of the PHY transmit
clock stop capability when deciding whether to allow the transmit clock
from the DWMAC core to be stopped.

Cc: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac.h     |  1 +
 .../net/ethernet/stmicro/stmmac/stmmac_main.c    | 16 ++++++++++++----
 include/linux/stmmac.h                           |  3 ++-
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index d87275c1cf23..bddfa0f4aa21 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -306,6 +306,7 @@ struct stmmac_priv {
 	struct timer_list eee_ctrl_timer;
 	int lpi_irq;
 	u32 tx_lpi_timer;
+	bool tx_lpi_clk_stop;
 	bool eee_enabled;
 	bool eee_active;
 	bool eee_sw_timer_en;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index fa1d7d3a2f43..6f29804148b6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -457,8 +457,7 @@ static void stmmac_try_to_start_sw_lpi(struct stmmac_priv *priv)
 	/* Check and enter in LPI mode */
 	if (!priv->tx_path_in_lpi_mode)
 		stmmac_set_lpi_mode(priv, priv->hw, STMMAC_LPI_FORCED,
-			priv->plat->flags & STMMAC_FLAG_EN_TX_LPI_CLOCKGATING,
-			0);
+				    priv->tx_lpi_clk_stop, 0);
 }
 
 /**
@@ -1104,13 +1103,18 @@ static int stmmac_mac_enable_tx_lpi(struct phylink_config *config, u32 timer,
 
 	priv->eee_enabled = true;
 
+	/* Update the transmit clock stop according to PHY capability if
+	 * the platform allows
+	 */
+	if (priv->plat->flags & STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP)
+		priv->tx_lpi_clk_stop = tx_clk_stop;
+
 	stmmac_set_eee_timer(priv, priv->hw, STMMAC_DEFAULT_LIT_LS,
 			     STMMAC_DEFAULT_TWT_LS);
 
 	/* Try to cnfigure the hardware timer. */
 	ret = stmmac_set_lpi_mode(priv, priv->hw, STMMAC_LPI_TIMER,
-				  priv->plat->flags & STMMAC_FLAG_EN_TX_LPI_CLOCKGATING,
-				  priv->tx_lpi_timer);
+				  priv->tx_lpi_clk_stop, priv->tx_lpi_timer);
 
 	if (ret) {
 		/* Hardware timer mode not supported, or value out of range.
@@ -1269,6 +1273,10 @@ static int stmmac_phy_setup(struct stmmac_priv *priv)
 	if (!(priv->plat->flags & STMMAC_FLAG_RX_CLK_RUNS_IN_LPI))
 		priv->phylink_config.eee_rx_clk_stop_enable = true;
 
+	/* Set the default transmit clock stop bit based on the platform glue */
+	priv->tx_lpi_clk_stop = priv->plat->flags &
+				STMMAC_FLAG_EN_TX_LPI_CLOCKGATING;
+
 	mdio_bus_data = priv->plat->mdio_bus_data;
 	if (mdio_bus_data)
 		priv->phylink_config.default_an_inband =
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index b6f03ab12595..c4ec8bb8144e 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -183,7 +183,8 @@ struct dwmac4_addrs {
 #define STMMAC_FLAG_INT_SNAPSHOT_EN		BIT(9)
 #define STMMAC_FLAG_RX_CLK_RUNS_IN_LPI		BIT(10)
 #define STMMAC_FLAG_EN_TX_LPI_CLOCKGATING	BIT(11)
-#define STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY	BIT(12)
+#define STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP	BIT(12)
+#define STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY	BIT(13)
 
 struct plat_stmmacenet_data {
 	int bus_id;
-- 
2.30.2