ax88796: add 93cx6 eeprom support

Hook up the 93cx6 eeprom code to the ax88796 driver and modify the ax88796
driver to read out the mac address from the eeprom.  We need this for the
ax88796 on certain SuperH boards.  The pin configuration used to connect
the eeprom to the ax88796 on these boards is the same as pointed out by the
ax88796 datasheet, so we can probably reuse this code for multiple
platforms in the future.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 56 insertions, 0 deletions

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 9ff1cf46eaee..45f6cf531566 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -240,6 +240,13 @@ config AX88796
           AX88796 driver, using platform bus to provide
           chip detection and resources
 
+config AX88796_93CX6
+        bool "ASIX AX88796 external 93CX6 eeprom support"
+        depends on AX88796
+        select EEPROM_93CX6
+        help
+          Select this if your platform comes with an external 93CX6 eeprom.
+
 config MACE
         tristate "MACE (Power Mac ethernet) support"
         depends on PPC_PMAC && PPC32
diff --git a/drivers/net/ax88796.c b/drivers/net/ax88796.c
index 90e0734e6037..9fe0517cf893 100644
--- a/drivers/net/ax88796.c
+++ b/drivers/net/ax88796.c
@@ -24,6 +24,7 @@
 #include <linux/etherdevice.h>
 #include <linux/ethtool.h>
 #include <linux/mii.h>
+#include <linux/eeprom_93cx6.h>
 
 #include <net/ax88796.h>
 
@@ -582,6 +583,37 @@ static const struct ethtool_ops ax_ethtool_ops = {
         .get_link               = ax_get_link,
 };
 
+#ifdef CONFIG_AX88796_93CX6
+static void ax_eeprom_register_read(struct eeprom_93cx6 *eeprom)
+{
+        struct ei_device *ei_local = eeprom->data;
+        u8 reg = ei_inb(ei_local->mem + AX_MEMR);
+
+        eeprom->reg_data_in = reg & AX_MEMR_EEI;
+        eeprom->reg_data_out = reg & AX_MEMR_EEO; /* Input pin */
+        eeprom->reg_data_clock = reg & AX_MEMR_EECLK;
+        eeprom->reg_chip_select = reg & AX_MEMR_EECS;
+}
+
+static void ax_eeprom_register_write(struct eeprom_93cx6 *eeprom)
+{
+        struct ei_device *ei_local = eeprom->data;
+        u8 reg = ei_inb(ei_local->mem + AX_MEMR);
+
+        reg &= ~(AX_MEMR_EEI | AX_MEMR_EECLK | AX_MEMR_EECS);
+
+        if (eeprom->reg_data_in)
+                reg |= AX_MEMR_EEI;
+        if (eeprom->reg_data_clock)
+                reg |= AX_MEMR_EECLK;
+        if (eeprom->reg_chip_select)
+                reg |= AX_MEMR_EECS;
+
+        ei_outb(reg, ei_local->mem + AX_MEMR);
+        udelay(10);
+}
+#endif
+
 /* setup code */
 
 static void ax_initial_setup(struct net_device *dev, struct ei_device *ei_local)
@@ -640,6 +672,23 @@ static int ax_init_dev(struct net_device *dev, int first_init)
                 memcpy(dev->dev_addr,  SA_prom, 6);
         }
 
+#ifdef CONFIG_AX88796_93CX6
+        if (first_init && ax->plat->flags & AXFLG_HAS_93CX6) {
+                unsigned char mac_addr[6];
+                struct eeprom_93cx6 eeprom;
+
+                eeprom.data = ei_local;
+                eeprom.register_read = ax_eeprom_register_read;
+                eeprom.register_write = ax_eeprom_register_write;
+                eeprom.width = PCI_EEPROM_WIDTH_93C56;
+
+                eeprom_93cx6_multiread(&eeprom, 0,
+                                       (__le16 __force *)mac_addr,
+                                       sizeof(mac_addr) >> 1);
+
+                memcpy(dev->dev_addr,  mac_addr, 6);
+        }
+#endif
         if (ax->plat->wordlength == 2) {
                 /* We must set the 8390 for word mode. */
                 ei_outb(ax->plat->dcr_val, ei_local->mem + EN0_DCFG);