From ac6e058b75be71208e98a5808453aae9a17be480 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Tue, 7 Feb 2017 06:20:24 +0100 Subject: [PATCH] net: phy: dp83867: Recover from "port mirroring" N/A MODE4 The DP83867 when not properly bootstrapped - especially with LED_0 pin - can enter N/A MODE4 for "port mirroring" feature. To provide normal operation of the PHY, one needs not only to explicitly disable the port mirroring feature, but as well stop some IC internal testing (which disables RGMII communication). To do that the STRAP_STS1 (0x006E) register must be read and RESERVED bit 11 examined. When it is set, the another RESERVED bit (11) at PHYCR (0x0010) register must be clear to disable testing mode and enable RGMII communication. Thorough explanation of the problem can be found at following e2e thread: "DP83867IR: Problem with RESERVED bits in PHY Control Register (PHYCR) - Linux driver" https://e2e.ti.com/support/interface/ethernet/f/903/p/571313/2096954#2096954 Signed-off-by: Lukasz Majewski Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/phy/dp83867.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c index be6fa24baf42..19865530e0b1 100644 --- a/drivers/net/phy/dp83867.c +++ b/drivers/net/phy/dp83867.c @@ -34,6 +34,7 @@ /* Extended Registers */ #define DP83867_CFG4 0x0031 #define DP83867_RGMIICTL 0x0032 +#define DP83867_STRAP_STS1 0x006E #define DP83867_RGMIIDCTL 0x0086 #define DP83867_IO_MUX_CFG 0x0170 @@ -58,9 +59,13 @@ #define DP83867_RGMII_TX_CLK_DELAY_EN BIT(1) #define DP83867_RGMII_RX_CLK_DELAY_EN BIT(0) +/* STRAP_STS1 bits */ +#define DP83867_STRAP_STS1_RESERVED BIT(11) + /* PHY CTRL bits */ #define DP83867_PHYCR_FIFO_DEPTH_SHIFT 14 #define DP83867_PHYCR_FIFO_DEPTH_MASK (3 << 14) +#define DP83867_PHYCR_RESERVED_MASK BIT(11) /* RGMIIDCTL bits */ #define DP83867_RGMII_TX_CLK_DELAY_SHIFT 4 @@ -192,7 +197,7 @@ static int dp83867_of_init(struct phy_device *phydev) static int dp83867_config_init(struct phy_device *phydev) { struct dp83867_private *dp83867; - int ret, val; + int ret, val, bs; u16 delay; if (!phydev->priv) { @@ -215,6 +220,22 @@ static int dp83867_config_init(struct phy_device *phydev) return val; val &= ~DP83867_PHYCR_FIFO_DEPTH_MASK; val |= (dp83867->fifo_depth << DP83867_PHYCR_FIFO_DEPTH_SHIFT); + + /* The code below checks if "port mirroring" N/A MODE4 has been + * enabled during power on bootstrap. + * + * Such N/A mode enabled by mistake can put PHY IC in some + * internal testing mode and disable RGMII transmission. + * + * In this particular case one needs to check STRAP_STS1 + * register's bit 11 (marked as RESERVED). + */ + + bs = phy_read_mmd_indirect(phydev, DP83867_STRAP_STS1, + DP83867_DEVADDR); + if (bs & DP83867_STRAP_STS1_RESERVED) + val &= ~DP83867_PHYCR_RESERVED_MASK; + ret = phy_write(phydev, MII_DP83867_PHYCTRL, val); if (ret) return ret;