phylib: add reset after clk enable support
Some PHYs need the refclk to be a continuous clock. Therefore they don't
allow turning it off and on again during operation. Nonetheless such a
clock switching is performed by some ETH drivers (namely FEC [1]) for
power saving reasons. An example for an affected PHY is the
SMSC/Microchip LAN8720 in "REF_CLK In Mode".
In order to provide a uniform method to overcome this problem this patch
adds a new phy_driver flag (PHY_RST_AFTER_CLK_EN) and corresponding
function phy_reset_after_clk_enable() to the phylib. These should be
used to trigger reset of the PHY after the refclk is switched on again.
[1] commit e8fcfcd5684a ("net: fec: optimize the clock management to save power")
Signed-off-by: Richard Leitner <richard.leitner@skidata.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/phy.h b/include/linux/phy.h
index d3037e2..c4b4715 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -59,6 +59,7 @@
#define PHY_HAS_INTERRUPT 0x00000001
#define PHY_IS_INTERNAL 0x00000002
+#define PHY_RST_AFTER_CLK_EN 0x00000004
#define MDIO_DEVICE_IS_PHY 0x80000000
/* Interface Mode definitions */
@@ -853,6 +854,7 @@ int phy_aneg_done(struct phy_device *phydev);
int phy_stop_interrupts(struct phy_device *phydev);
int phy_restart_aneg(struct phy_device *phydev);
+int phy_reset_after_clk_enable(struct phy_device *phydev);
static inline void phy_device_reset(struct phy_device *phydev, int value)
{