From: Raju Lakkaraju <raju.lakkar...@microsemi.com>
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.lakkar...@microsemi.com>
Signed-off-by: Allan W. Nielsen <allan.niel...@microsemi.com>
---
.../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
