net/phy: Add the autocross feature for forced links on VSC82x4

Add auto-MDI/MDI-X capability for forced (autonegotiation disabled)
10/100 Mbps speeds on Vitesse VSC82x4 PHYs. Exported previously static
function genphy_setup_forced() required by the new config_aneg handler
in the Vitesse PHY module.

Signed-off-by: Madalin Bucur <madalin.bucur@freescale.com>
Signed-off-by: Shruti Kanetkar <Shruti@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 73 insertions, 7 deletions

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 74630e94fa3b..d6447b3f7409 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -697,7 +697,7 @@ static int genphy_config_advert(struct phy_device *phydev)
  *   to the values in phydev. Assumes that the values are valid.
  *   Please see phy_sanitize_settings().
  */
-static int genphy_setup_forced(struct phy_device *phydev)
+int genphy_setup_forced(struct phy_device *phydev)
 {
         int err;
         int ctl = 0;
@@ -716,7 +716,7 @@ static int genphy_setup_forced(struct phy_device *phydev)
 
         return err;
 }
-
+EXPORT_SYMBOL(genphy_setup_forced);
 
 /**
  * genphy_restart_aneg - Enable and Restart Autonegotiation
diff --git a/drivers/net/phy/vitesse.c b/drivers/net/phy/vitesse.c
index 40406bc2f8af..508e4359338b 100644
--- a/drivers/net/phy/vitesse.c
+++ b/drivers/net/phy/vitesse.c
@@ -3,7 +3,7 @@
  *
  * Author: Kriston Carson
  *
- * Copyright (c) 2005, 2009 Freescale Semiconductor, Inc.
+ * Copyright (c) 2005, 2009, 2011 Freescale Semiconductor, Inc.
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
@@ -18,6 +18,11 @@
 #include <linux/ethtool.h>
 #include <linux/phy.h>
 
+/* Vitesse Extended Page Magic Register(s) */
+#define MII_VSC82X4_EXT_PAGE_16E        0x10
+#define MII_VSC82X4_EXT_PAGE_17E        0x11
+#define MII_VSC82X4_EXT_PAGE_18E        0x12
+
 /* Vitesse Extended Control Register 1 */
 #define MII_VSC8244_EXT_CON1           0x17
 #define MII_VSC8244_EXTCON1_INIT       0x0000
@@ -54,6 +59,9 @@
 #define MII_VSC8221_AUXCONSTAT_INIT     0x0004 /* need to set this bit? */
 #define MII_VSC8221_AUXCONSTAT_RESERVED 0x0004
 
+/* Vitesse Extended Page Access Register */
+#define MII_VSC82X4_EXT_PAGE_ACCESS     0x1f
+
 #define PHY_ID_VSC8234                  0x000fc620
 #define PHY_ID_VSC8244                  0x000fc6c0
 #define PHY_ID_VSC8574                  0x000704a0
@@ -154,6 +162,63 @@ static int vsc8221_config_init(struct phy_device *phydev)
          */
 }
 
+/* vsc82x4_config_autocross_enable - Enable auto MDI/MDI-X for forced links
+ * @phydev: target phy_device struct
+ *
+ * Enable auto MDI/MDI-X when in 10/100 forced link speeds by writing
+ * special values in the VSC8234/VSC8244 extended reserved registers
+ */
+static int vsc82x4_config_autocross_enable(struct phy_device *phydev)
+{
+        int ret;
+
+        if (phydev->autoneg == AUTONEG_ENABLE || phydev->speed > SPEED_100)
+                return 0;
+
+        /* map extended registers set 0x10 - 0x1e */
+        ret = phy_write(phydev, MII_VSC82X4_EXT_PAGE_ACCESS, 0x52b5);
+        if (ret >= 0)
+                ret = phy_write(phydev, MII_VSC82X4_EXT_PAGE_18E, 0x0012);
+        if (ret >= 0)
+                ret = phy_write(phydev, MII_VSC82X4_EXT_PAGE_17E, 0x2803);
+        if (ret >= 0)
+                ret = phy_write(phydev, MII_VSC82X4_EXT_PAGE_16E, 0x87fa);
+        /* map standard registers set 0x10 - 0x1e */
+        if (ret >= 0)
+                ret = phy_write(phydev, MII_VSC82X4_EXT_PAGE_ACCESS, 0x0000);
+        else
+                phy_write(phydev, MII_VSC82X4_EXT_PAGE_ACCESS, 0x0000);
+
+        return ret;
+}
+
+/* vsc82x4_config_aneg - restart auto-negotiation or write BMCR
+ * @phydev: target phy_device struct
+ *
+ * Description: If auto-negotiation is enabled, we configure the
+ *   advertising, and then restart auto-negotiation.  If it is not
+ *   enabled, then we write the BMCR and also start the auto
+ *   MDI/MDI-X feature
+ */
+static int vsc82x4_config_aneg(struct phy_device *phydev)
+{
+        int ret;
+
+        /* Enable auto MDI/MDI-X when in 10/100 forced link speeds by
+         * writing special values in the VSC8234 extended reserved registers
+         */
+        if (phydev->autoneg != AUTONEG_ENABLE && phydev->speed <= SPEED_100) {
+                ret = genphy_setup_forced(phydev);
+
+                if (ret < 0) /* error */
+                        return ret;
+
+                return vsc82x4_config_autocross_enable(phydev);
+        }
+
+        return genphy_config_aneg(phydev);
+}
+
 /* Vitesse 82xx */
 static struct phy_driver vsc82xx_driver[] = {
 {
@@ -163,7 +228,7 @@ static struct phy_driver vsc82xx_driver[] = {
         .features       = PHY_GBIT_FEATURES,
         .flags          = PHY_HAS_INTERRUPT,
         .config_init    = &vsc824x_config_init,
-        .config_aneg    = &genphy_config_aneg,
+        .config_aneg    = &vsc82x4_config_aneg,
         .read_status    = &genphy_read_status,
         .ack_interrupt  = &vsc824x_ack_interrupt,
         .config_intr    = &vsc82xx_config_intr,
@@ -175,7 +240,7 @@ static struct phy_driver vsc82xx_driver[] = {
         .features       = PHY_GBIT_FEATURES,
         .flags          = PHY_HAS_INTERRUPT,
         .config_init    = &vsc824x_config_init,
-        .config_aneg    = &genphy_config_aneg,
+        .config_aneg    = &vsc82x4_config_aneg,
         .read_status    = &genphy_read_status,
         .ack_interrupt  = &vsc824x_ack_interrupt,
         .config_intr    = &vsc82xx_config_intr,
@@ -187,7 +252,7 @@ static struct phy_driver vsc82xx_driver[] = {
         .features       = PHY_GBIT_FEATURES,
         .flags          = PHY_HAS_INTERRUPT,
         .config_init    = &vsc824x_config_init,
-        .config_aneg    = &genphy_config_aneg,
+        .config_aneg    = &vsc82x4_config_aneg,
         .read_status    = &genphy_read_status,
         .ack_interrupt  = &vsc824x_ack_interrupt,
         .config_intr    = &vsc82xx_config_intr,
@@ -199,7 +264,7 @@ static struct phy_driver vsc82xx_driver[] = {
         .features       = PHY_GBIT_FEATURES,
         .flags          = PHY_HAS_INTERRUPT,
         .config_init    = &vsc824x_config_init,
-        .config_aneg    = &genphy_config_aneg,
+        .config_aneg    = &vsc82x4_config_aneg,
         .read_status    = &genphy_read_status,
         .ack_interrupt  = &vsc824x_ack_interrupt,
         .config_intr    = &vsc82xx_config_intr,
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 64ab823f7b74..48a4dc3cb8cf 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -559,6 +559,7 @@ static inline int phy_read_status(struct phy_device *phydev) {
         return phydev->drv->read_status(phydev);
 }
 
+int genphy_setup_forced(struct phy_device *phydev);
 int genphy_restart_aneg(struct phy_device *phydev);
 int genphy_config_aneg(struct phy_device *phydev);
 int genphy_update_link(struct phy_device *phydev);