net/fec: add dual fec support for mx28

This patch is to add mx28 dual fec support. Here are some key notes
for mx28 fec controller.

 - The mx28 fec controller naming ENET-MAC is a different IP from FEC
   used on other i.mx variants.  But they are basically compatible
   on software interface, so it's possible to share the same driver.
 - ENET-MAC design on mx28 made an improper assumption that it runs
   on a big-endian system. As the result, driver has to swap every
   frame going to and coming from the controller.
 - The external phys can only be configured by fec0, which means fec1
   can not work independently and both phys need to be configured by
   mii_bus attached on fec0.
 - ENET-MAC reset will get mac address registers reset too.
 - ENET-MAC MII/RMII mode and 10M/100M speed are configured
   differently FEC.
 - ETHER_EN bit must be set to get ENET-MAC interrupt work.

Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 139 insertions, 21 deletions

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 3fda24a28d2..5780dad6a3c 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -1944,18 +1944,19 @@ config 68360_ENET
 config FEC
         bool "FEC ethernet controller (of ColdFire and some i.MX CPUs)"
         depends on M523x || M527x || M5272 || M528x || M520x || M532x || \
-                MACH_MX27 || ARCH_MX35 || ARCH_MX25 || ARCH_MX5
+                MACH_MX27 || ARCH_MX35 || ARCH_MX25 || ARCH_MX5 || SOC_IMX28
         select PHYLIB
         help
           Say Y here if you want to use the built-in 10/100 Fast ethernet
           controller on some Motorola ColdFire and Freescale i.MX processors.
 
 config FEC2
-        bool "Second FEC ethernet controller (on some ColdFire CPUs)"
+        bool "Second FEC ethernet controller"
         depends on FEC
         help
           Say Y here if you want to use the second built-in 10/100 Fast
-          ethernet controller on some Motorola ColdFire processors.
+          ethernet controller on some Motorola ColdFire and Freescale
+          i.MX processors.
 
 config FEC_MPC52xx
         tristate "MPC52xx FEC driver"
diff --git a/drivers/net/fec.c b/drivers/net/fec.c
index 8a1c51f8641..2a71373719a 100644
--- a/drivers/net/fec.c
+++ b/drivers/net/fec.c
@@ -17,6 +17,8 @@
  *
  * Bug fixes and cleanup by Philippe De Muyter (phdm@macqel.be)
  * Copyright (c) 2004-2006 Macq Electronique SA.
+ *
+ * Copyright (C) 2010 Freescale Semiconductor, Inc.
  */
 
 #include <linux/module.h>
@@ -45,20 +47,36 @@
 
 #include <asm/cacheflush.h>
 
-#ifndef CONFIG_ARCH_MXC
+#ifndef CONFIG_ARM
 #include <asm/coldfire.h>
 #include <asm/mcfsim.h>
 #endif
 
 #include "fec.h"
 
-#ifdef CONFIG_ARCH_MXC
-#include <mach/hardware.h>
+#if defined(CONFIG_ARCH_MXC) || defined(CONFIG_SOC_IMX28)
 #define FEC_ALIGNMENT   0xf
 #else
 #define FEC_ALIGNMENT   0x3
 #endif
 
+#define DRIVER_NAME     "fec"
+
+/* Controller is ENET-MAC */
+#define FEC_QUIRK_ENET_MAC              (1 << 0)
+/* Controller needs driver to swap frame */
+#define FEC_QUIRK_SWAP_FRAME            (1 << 1)
+
+static struct platform_device_id fec_devtype[] = {
+        {
+                .name = DRIVER_NAME,
+                .driver_data = 0,
+        }, {
+                .name = "imx28-fec",
+                .driver_data = FEC_QUIRK_ENET_MAC | FEC_QUIRK_SWAP_FRAME,
+        }
+};
+
 static unsigned char macaddr[ETH_ALEN];
 module_param_array(macaddr, byte, NULL, 0);
 MODULE_PARM_DESC(macaddr, "FEC Ethernet MAC address");
@@ -129,7 +147,8 @@ MODULE_PARM_DESC(macaddr, "FEC Ethernet MAC address");
  * account when setting it.
  */
 #if defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x) || \
-    defined(CONFIG_M520x) || defined(CONFIG_M532x) || defined(CONFIG_ARCH_MXC)
+    defined(CONFIG_M520x) || defined(CONFIG_M532x) || \
+    defined(CONFIG_ARCH_MXC) || defined(CONFIG_SOC_IMX28)
 #define OPT_FRAME_SIZE  (PKT_MAXBUF_SIZE << 16)
 #else
 #define OPT_FRAME_SIZE  0
@@ -208,10 +227,23 @@ static void fec_stop(struct net_device *dev);
 /* Transmitter timeout */
 #define TX_TIMEOUT (2 * HZ)
 
+static void *swap_buffer(void *bufaddr, int len)
+{
+        int i;
+        unsigned int *buf = bufaddr;
+
+        for (i = 0; i < (len + 3) / 4; i++, buf++)
+                *buf = cpu_to_be32(*buf);
+
+        return bufaddr;
+}
+
 static netdev_tx_t
 fec_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct fec_enet_private *fep = netdev_priv(dev);
+        const struct platform_device_id *id_entry =
+                                platform_get_device_id(fep->pdev);
         struct bufdesc *bdp;
         void *bufaddr;
         unsigned short  status;
@@ -256,6 +288,14 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                 bufaddr = fep->tx_bounce[index];
         }
 
+        /*
+         * Some design made an incorrect assumption on endian mode of
+         * the system that it's running on. As the result, driver has to
+         * swap every frame going to and coming from the controller.
+         */
+        if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME)
+                swap_buffer(bufaddr, skb->len);
+
         /* Save skb pointer */
         fep->tx_skbuff[fep->skb_cur] = skb;
 
@@ -424,6 +464,8 @@ static void
 fec_enet_rx(struct net_device *dev)
 {
         struct  fec_enet_private *fep = netdev_priv(dev);
+        const struct platform_device_id *id_entry =
+                                platform_get_device_id(fep->pdev);
         struct bufdesc *bdp;
         unsigned short status;
         struct  sk_buff *skb;
@@ -487,6 +529,9 @@ fec_enet_rx(struct net_device *dev)
                 dma_unmap_single(NULL, bdp->cbd_bufaddr, bdp->cbd_datlen,
                                 DMA_FROM_DEVICE);
 
+                if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME)
+                        swap_buffer(data, pkt_len);
+
                 /* This does 16 byte alignment, exactly what we need.
                  * The packet length includes FCS, but we don't want to
                  * include that when passing upstream as it messes up
@@ -689,6 +734,7 @@ static int fec_enet_mii_probe(struct net_device *dev)
         char mdio_bus_id[MII_BUS_ID_SIZE];
         char phy_name[MII_BUS_ID_SIZE + 3];
         int phy_id;
+        int dev_id = fep->pdev->id;
 
         fep->phy_dev = NULL;
 
@@ -700,6 +746,8 @@ static int fec_enet_mii_probe(struct net_device *dev)
                         continue;
                 if (fep->mii_bus->phy_map[phy_id]->phy_id == 0)
                         continue;
+                if (dev_id--)
+                        continue;
                 strncpy(mdio_bus_id, fep->mii_bus->id, MII_BUS_ID_SIZE);
                 break;
         }
@@ -737,10 +785,35 @@ static int fec_enet_mii_probe(struct net_device *dev)
 
 static int fec_enet_mii_init(struct platform_device *pdev)
 {
+        static struct mii_bus *fec0_mii_bus;
         struct net_device *dev = platform_get_drvdata(pdev);
         struct fec_enet_private *fep = netdev_priv(dev);
+        const struct platform_device_id *id_entry =
+                                platform_get_device_id(fep->pdev);
         int err = -ENXIO, i;
 
+        /*
+         * The dual fec interfaces are not equivalent with enet-mac.
+         * Here are the differences:
+         *
+         *  - fec0 supports MII & RMII modes while fec1 only supports RMII
+         *  - fec0 acts as the 1588 time master while fec1 is slave
+         *  - external phys can only be configured by fec0
+         *
+         * That is to say fec1 can not work independently. It only works
+         * when fec0 is working. The reason behind this design is that the
+         * second interface is added primarily for Switch mode.
+         *
+         * Because of the last point above, both phys are attached on fec0
+         * mdio interface in board design, and need to be configured by
+         * fec0 mii_bus.
+         */
+        if ((id_entry->driver_data & FEC_QUIRK_ENET_MAC) && pdev->id) {
+                /* fec1 uses fec0 mii_bus */
+                fep->mii_bus = fec0_mii_bus;
+                return 0;
+        }
+
         fep->mii_timeout = 0;
 
         /*
@@ -777,6 +850,10 @@ static int fec_enet_mii_init(struct platform_device *pdev)
         if (mdiobus_register(fep->mii_bus))
                 goto err_out_free_mdio_irq;
 
+        /* save fec0 mii_bus */
+        if (id_entry->driver_data & FEC_QUIRK_ENET_MAC)
+                fec0_mii_bus = fep->mii_bus;
+
         return 0;
 
 err_out_free_mdio_irq:
@@ -1148,12 +1225,25 @@ static void
 fec_restart(struct net_device *dev, int duplex)
 {
         struct fec_enet_private *fep = netdev_priv(dev);
+        const struct platform_device_id *id_entry =
+                                platform_get_device_id(fep->pdev);
         int i;
+        u32 val, temp_mac[2];
 
         /* Whack a reset.  We should wait for this. */
         writel(1, fep->hwp + FEC_ECNTRL);
         udelay(10);
 
+        /*
+         * enet-mac reset will reset mac address registers too,
+         * so need to reconfigure it.
+         */
+        if (id_entry->driver_data & FEC_QUIRK_ENET_MAC) {
+                memcpy(&temp_mac, dev->dev_addr, ETH_ALEN);
+                writel(cpu_to_be32(temp_mac[0]), fep->hwp + FEC_ADDR_LOW);
+                writel(cpu_to_be32(temp_mac[1]), fep->hwp + FEC_ADDR_HIGH);
+        }
+
         /* Clear any outstanding interrupt. */
         writel(0xffc00000, fep->hwp + FEC_IEVENT);
 
@@ -1200,20 +1290,45 @@ fec_restart(struct net_device *dev, int duplex)
         /* Set MII speed */
         writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);
 
-#ifdef FEC_MIIGSK_ENR
-        if (fep->phy_interface == PHY_INTERFACE_MODE_RMII) {
-                /* disable the gasket and wait */
-                writel(0, fep->hwp + FEC_MIIGSK_ENR);
-                while (readl(fep->hwp + FEC_MIIGSK_ENR) & 4)
-                        udelay(1);
+        /*
+         * The phy interface and speed need to get configured
+         * differently on enet-mac.
+         */
+        if (id_entry->driver_data & FEC_QUIRK_ENET_MAC) {
+                val = readl(fep->hwp + FEC_R_CNTRL);
 
-                /* configure the gasket: RMII, 50 MHz, no loopback, no echo */
-                writel(1, fep->hwp + FEC_MIIGSK_CFGR);
+                /* MII or RMII */
+                if (fep->phy_interface == PHY_INTERFACE_MODE_RMII)
+                        val |= (1 << 8);
+                else
+                        val &= ~(1 << 8);
 
-                /* re-enable the gasket */
-                writel(2, fep->hwp + FEC_MIIGSK_ENR);
-        }
+                /* 10M or 100M */
+                if (fep->phy_dev && fep->phy_dev->speed == SPEED_100)
+                        val &= ~(1 << 9);
+                else
+                        val |= (1 << 9);
+
+                writel(val, fep->hwp + FEC_R_CNTRL);
+        } else {
+#ifdef FEC_MIIGSK_ENR
+                if (fep->phy_interface == PHY_INTERFACE_MODE_RMII) {
+                        /* disable the gasket and wait */
+                        writel(0, fep->hwp + FEC_MIIGSK_ENR);
+                        while (readl(fep->hwp + FEC_MIIGSK_ENR) & 4)
+                                udelay(1);
+
+                        /*
+                         * configure the gasket:
+                         *   RMII, 50 MHz, no loopback, no echo
+                         */
+                        writel(1, fep->hwp + FEC_MIIGSK_CFGR);
+
+                        /* re-enable the gasket */
+                        writel(2, fep->hwp + FEC_MIIGSK_ENR);
+                }
 #endif
+        }
 
         /* And last, enable the transmit and receive processing */
         writel(2, fep->hwp + FEC_ECNTRL);
@@ -1410,12 +1525,13 @@ static const struct dev_pm_ops fec_pm_ops = {
 
 static struct platform_driver fec_driver = {
         .driver = {
-                .name   = "fec",
+                .name   = DRIVER_NAME,
                 .owner  = THIS_MODULE,
 #ifdef CONFIG_PM
                 .pm     = &fec_pm_ops,
 #endif
         },
+        .id_table = fec_devtype,
         .probe  = fec_probe,
         .remove = __devexit_p(fec_drv_remove),
 };
diff --git a/drivers/net/fec.h b/drivers/net/fec.h
index 2c48b25668d..ace318df4c8 100644
--- a/drivers/net/fec.h
+++ b/drivers/net/fec.h
@@ -14,7 +14,8 @@
 /****************************************************************************/
 
 #if defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x) || \
-    defined(CONFIG_M520x) || defined(CONFIG_M532x) || defined(CONFIG_ARCH_MXC)
+    defined(CONFIG_M520x) || defined(CONFIG_M532x) || \
+    defined(CONFIG_ARCH_MXC) || defined(CONFIG_SOC_IMX28)
 /*
  *      Just figures, Motorola would have to change the offsets for
  *      registers in the same peripheral device on different models
@@ -78,7 +79,7 @@
 /*
  *      Define the buffer descriptor structure.
  */
-#ifdef CONFIG_ARCH_MXC
+#if defined(CONFIG_ARCH_MXC) || defined(CONFIG_SOC_IMX28)
 struct bufdesc {
         unsigned short cbd_datlen;      /* Data length */
         unsigned short cbd_sc;  /* Control and status info */