net: phy: broadcom: Add support code for downshift/Wirespeed
Broadcom's Wirespeed feature allows us to configure how auto-negotiation
should behave with fewer working pairs of wires on a cable. Add support
code for retrieving and setting such downshift counters using the
recently added ethtool downshift tunables.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/bcm-phy-lib.c b/drivers/net/phy/bcm-phy-lib.c
index 18e11b3..d742894 100644
--- a/drivers/net/phy/bcm-phy-lib.c
+++ b/drivers/net/phy/bcm-phy-lib.c
@@ -225,6 +225,92 @@
}
EXPORT_SYMBOL_GPL(bcm_phy_enable_eee);
+int bcm_phy_downshift_get(struct phy_device *phydev, u8 *count)
+{
+ int val;
+
+ val = bcm54xx_auxctl_read(phydev, MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
+ if (val < 0)
+ return val;
+
+ /* Check if wirespeed is enabled or not */
+ if (!(val & MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN)) {
+ *count = DOWNSHIFT_DEV_DISABLE;
+ return 0;
+ }
+
+ val = bcm_phy_read_shadow(phydev, BCM54XX_SHD_SCR2);
+ if (val < 0)
+ return val;
+
+ /* Downgrade after one link attempt */
+ if (val & BCM54XX_SHD_SCR2_WSPD_RTRY_DIS) {
+ *count = 1;
+ } else {
+ /* Downgrade after configured retry count */
+ val >>= BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT;
+ val &= BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_MASK;
+ *count = val + BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_OFFSET;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(bcm_phy_downshift_get);
+
+int bcm_phy_downshift_set(struct phy_device *phydev, u8 count)
+{
+ int val = 0, ret = 0;
+
+ /* Range check the number given */
+ if (count - BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_OFFSET >
+ BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_MASK &&
+ count != DOWNSHIFT_DEV_DEFAULT_COUNT) {
+ return -ERANGE;
+ }
+
+ val = bcm54xx_auxctl_read(phydev, MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
+ if (val < 0)
+ return val;
+
+ /* Se the write enable bit */
+ val |= MII_BCM54XX_AUXCTL_MISC_WREN;
+
+ if (count == DOWNSHIFT_DEV_DISABLE) {
+ val &= ~MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN;
+ return bcm54xx_auxctl_write(phydev,
+ MII_BCM54XX_AUXCTL_SHDWSEL_MISC,
+ val);
+ } else {
+ val |= MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN;
+ ret = bcm54xx_auxctl_write(phydev,
+ MII_BCM54XX_AUXCTL_SHDWSEL_MISC,
+ val);
+ if (ret < 0)
+ return ret;
+ }
+
+ val = bcm_phy_read_shadow(phydev, BCM54XX_SHD_SCR2);
+ val &= ~(BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_MASK <<
+ BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT |
+ BCM54XX_SHD_SCR2_WSPD_RTRY_DIS);
+
+ switch (count) {
+ case 1:
+ val |= BCM54XX_SHD_SCR2_WSPD_RTRY_DIS;
+ break;
+ case DOWNSHIFT_DEV_DEFAULT_COUNT:
+ val |= 1 << BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT;
+ break;
+ default:
+ val |= (count - BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_OFFSET) <<
+ BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT;
+ break;
+ }
+
+ return bcm_phy_write_shadow(phydev, BCM54XX_SHD_SCR2, val);
+}
+EXPORT_SYMBOL_GPL(bcm_phy_downshift_set);
+
MODULE_DESCRIPTION("Broadcom PHY Library");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Broadcom Corporation");