From: Raju Lakkaraju <Raju.Lakkaraju@xxxxxxxxxxxxx> For operation in cabling environments that are incompatible with 1000BAST-T, VSC8531 device provides an automatic link speed downshift operation. When enabled, the device automatically changes its 1000BAST-T auto-negotiation to the next slower speed after a configured number of failed attempts at 1000BAST-T. This feature is useful in setting up in networks using older cable installations that include only pairs A and B, and not pairs C and D. Signed-off-by: Raju Lakkaraju <Raju.Lakkaraju@xxxxxxxxxxxxx> Signed-off-by: Allan W. Nielsen <allan.nielsen@xxxxxxxxxxxxx> --- .../devicetree/bindings/net/mscc-phy-vsc8531.txt | 6 ++ drivers/net/phy/mscc.c | 75 +++++++++++++++++++++- 2 files changed, 80 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/net/mscc-phy-vsc8531.txt b/Documentation/devicetree/bindings/net/mscc-phy-vsc8531.txt index bdefefc6..062d115 100644 --- a/Documentation/devicetree/bindings/net/mscc-phy-vsc8531.txt +++ b/Documentation/devicetree/bindings/net/mscc-phy-vsc8531.txt @@ -27,6 +27,11 @@ Optional properties: 'vddmac'. Default value is 0%. Ref: Table:1 - Edge rate change (below). +- downshift-cnt : When enabled, the device automatically changes its + 1000BAST-T auto-negotiation to the next slower speed + after a 'downshift-cnt' of failed attempts at + 1000BAST-T. Allowed values: 0, 2, 3, 4, 5. + 0 is default and will disable downshifting. Table: 1 - Edge rate change ----------------------------------------------------------------| @@ -60,4 +65,5 @@ Example: compatible = "ethernet-phy-id0007.0570"; vsc8531,vddmac = <3300>; vsc8531,edge-slowdown = <7>; + vsc8531,downshift-cnt = <3>; }; diff --git a/drivers/net/phy/mscc.c b/drivers/net/phy/mscc.c index 43a7545..e87d9f0 100644 --- a/drivers/net/phy/mscc.c +++ b/drivers/net/phy/mscc.c @@ -46,8 +46,15 @@ enum rgmii_rx_clock_delay { #define MSCC_EXT_PAGE_ACCESS 31 #define MSCC_PHY_PAGE_STANDARD 0x0000 /* Standard registers */ +#define MSCC_PHY_PAGE_EXTENDED 0x0001 /* Extended registers */ #define MSCC_PHY_PAGE_EXTENDED_2 0x0002 /* Extended reg - page 2 */ +/* Extended Page 1 Registers */ +#define MSCC_PHY_ACTIPHY_CNTL 20 +#define DOWNSHIFT_CNTL_MASK 0x000C +#define DOWNSHIFT_EN 0x0010 +#define DOWNSHIFT_CNTL_POS 2 + /* Extended Page 2 Registers */ #define MSCC_PHY_RGMII_CNTL 20 #define RGMII_RX_CLK_DELAY_MASK 0x0070 @@ -75,6 +82,7 @@ enum rgmii_rx_clock_delay { struct vsc8531_private { int rate_magic; + u8 downshift_magic; }; #ifdef CONFIG_OF_MDIO @@ -99,6 +107,31 @@ static int vsc85xx_phy_page_set(struct phy_device *phydev, u8 page) return rc; } +static int vsc85xx_downshift_set(struct phy_device *phydev, u8 magic) +{ + int rc; + u16 reg_val; + + mutex_lock(&phydev->lock); + rc = vsc85xx_phy_page_set(phydev, MSCC_PHY_PAGE_EXTENDED); + if (rc != 0) + goto out_unlock; + + reg_val = phy_read(phydev, MSCC_PHY_ACTIPHY_CNTL); + reg_val &= ~(DOWNSHIFT_CNTL_MASK); + reg_val |= magic; + rc = phy_write(phydev, MSCC_PHY_ACTIPHY_CNTL, reg_val); + if (rc != 0) + goto out_unlock; + + rc = vsc85xx_phy_page_set(phydev, MSCC_PHY_PAGE_STANDARD); + +out_unlock: + mutex_unlock(&phydev->lock); + + return rc; +} + static int vsc85xx_wol_set(struct phy_device *phydev, struct ethtool_wolinfo *wol) { @@ -239,11 +272,42 @@ static int vsc85xx_edge_rate_magic_get(struct phy_device *phydev) return -EINVAL; } + +static int vsc85xx_downshift_magic_get(struct phy_device *phydev) +{ + int rc; + u8 ds; + struct device *dev = &phydev->mdio.dev; + struct device_node *of_node = dev->of_node; + + if (!of_node) + return -ENODEV; + + rc = of_property_read_u8(of_node, "vsc8531,downshift-cnt", &ds); + if ((rc == -EINVAL) || (ds == 0)) + return 0; + if (ds == 1 || ds > 5) { + phydev_err(phydev, "Invalid downshift count\n"); + return -EINVAL; + } + + /* ds is either 2,3,4 or 5 */ + ds -= 2; + ds <<= DOWNSHIFT_CNTL_POS; + ds |= DOWNSHIFT_EN; + + return ds; +} #else static int vsc85xx_edge_rate_magic_get(struct phy_device *phydev) { return 0; } + +static int vsc85xx_downshift_magic_get(struct phy_device *phydev) +{ + return 0; +} #endif /* CONFIG_OF_MDIO */ static int vsc85xx_edge_rate_cntl_set(struct phy_device *phydev, u8 edge_rate) @@ -344,6 +408,10 @@ static int vsc85xx_config_init(struct phy_device *phydev) if (rc) return rc; + rc = vsc85xx_downshift_set(phydev, vsc8531->downshift_magic); + if (rc) + return rc; + rc = genphy_config_init(phydev); return rc; @@ -379,19 +447,24 @@ static int vsc85xx_config_intr(struct phy_device *phydev) static int vsc85xx_probe(struct phy_device *phydev) { int rate_magic; + int downshift_magic; struct vsc8531_private *vsc8531; rate_magic = vsc85xx_edge_rate_magic_get(phydev); if (rate_magic < 0) return rate_magic; + downshift_magic = vsc85xx_downshift_magic_get(phydev); + if (downshift_magic < 0) + return downshift_magic; + vsc8531 = devm_kzalloc(&phydev->mdio.dev, sizeof(*vsc8531), GFP_KERNEL); if (!vsc8531) return -ENOMEM; phydev->priv = vsc8531; - vsc8531->rate_magic = rate_magic; + vsc8531->downshift_magic = downshift_magic; return 0; } -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html