ssb: Fix PCMCIA lowlevel register access

This fixes lowlevel register access for PCMCIA based devices.

The patch also adds a temporary workaround for the device mac address.
It simply adds generation of a random address. The real SPROM extraction
will follow in another patch.
The temporary workaround will be removed then, but for now it's OK.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 45 insertions, 29 deletions

diff --git a/drivers/ssb/pcmcia.c b/drivers/ssb/pcmcia.c
index bb44a76b3eb5..46816cda8b98 100644
--- a/drivers/ssb/pcmcia.c
+++ b/drivers/ssb/pcmcia.c
@@ -94,7 +94,6 @@ int ssb_pcmcia_switch_core(struct ssb_bus *bus,
                            struct ssb_device *dev)
 {
         int err;
-        unsigned long flags;
 
 #if SSB_VERBOSE_PCMCIACORESWITCH_DEBUG
         ssb_printk(KERN_INFO PFX
@@ -103,11 +102,9 @@ int ssb_pcmcia_switch_core(struct ssb_bus *bus,
                    dev->core_index);
 #endif
 
-        spin_lock_irqsave(&bus->bar_lock, flags);
         err = ssb_pcmcia_switch_coreidx(bus, dev->core_index);
         if (!err)
                 bus->mapped_device = dev;
-        spin_unlock_irqrestore(&bus->bar_lock, flags);
 
         return err;
 }
@@ -115,14 +112,12 @@ int ssb_pcmcia_switch_core(struct ssb_bus *bus,
 int ssb_pcmcia_switch_segment(struct ssb_bus *bus, u8 seg)
 {
         int attempts = 0;
-        unsigned long flags;
         conf_reg_t reg;
-        int res, err = 0;
+        int res;
 
         SSB_WARN_ON((seg != 0) && (seg != 1));
         reg.Offset = 0x34;
         reg.Function = 0;
-        spin_lock_irqsave(&bus->bar_lock, flags);
         while (1) {
                 reg.Action = CS_WRITE;
                 reg.Value = seg;
@@ -143,13 +138,11 @@ int ssb_pcmcia_switch_segment(struct ssb_bus *bus, u8 seg)
                 udelay(10);
         }
         bus->mapped_pcmcia_seg = seg;
-out_unlock:
-        spin_unlock_irqrestore(&bus->bar_lock, flags);
-        return err;
+
+        return 0;
 error:
         ssb_printk(KERN_ERR PFX "Failed to switch pcmcia segment\n");
-        err = -ENODEV;
-        goto out_unlock;
+        return -ENODEV;
 }
 
 static int select_core_and_segment(struct ssb_device *dev,
@@ -182,22 +175,33 @@ static int select_core_and_segment(struct ssb_device *dev,
 static u16 ssb_pcmcia_read16(struct ssb_device *dev, u16 offset)
 {
         struct ssb_bus *bus = dev->bus;
+        unsigned long flags;
+        int err;
+        u16 value = 0xFFFF;
 
-        if (unlikely(select_core_and_segment(dev, &offset)))
-                return 0xFFFF;
+        spin_lock_irqsave(&bus->bar_lock, flags);
+        err = select_core_and_segment(dev, &offset);
+        if (likely(!err))
+                value = readw(bus->mmio + offset);
+        spin_unlock_irqrestore(&bus->bar_lock, flags);
 
-        return readw(bus->mmio + offset);
+        return value;
 }
 
 static u32 ssb_pcmcia_read32(struct ssb_device *dev, u16 offset)
 {
         struct ssb_bus *bus = dev->bus;
-        u32 lo, hi;
+        unsigned long flags;
+        int err;
+        u32 lo = 0xFFFFFFFF, hi = 0xFFFFFFFF;
 
-        if (unlikely(select_core_and_segment(dev, &offset)))
-                return 0xFFFFFFFF;
-        lo = readw(bus->mmio + offset);
-        hi = readw(bus->mmio + offset + 2);
+        spin_lock_irqsave(&bus->bar_lock, flags);
+        err = select_core_and_segment(dev, &offset);
+        if (likely(!err)) {
+                lo = readw(bus->mmio + offset);
+                hi = readw(bus->mmio + offset + 2);
+        }
+        spin_unlock_irqrestore(&bus->bar_lock, flags);
 
         return (lo | (hi << 16));
 }
@@ -205,22 +209,31 @@ static u32 ssb_pcmcia_read32(struct ssb_device *dev, u16 offset)
 static void ssb_pcmcia_write16(struct ssb_device *dev, u16 offset, u16 value)
 {
         struct ssb_bus *bus = dev->bus;
+        unsigned long flags;
+        int err;
 
-        if (unlikely(select_core_and_segment(dev, &offset)))
-                return;
-        writew(value, bus->mmio + offset);
+        spin_lock_irqsave(&bus->bar_lock, flags);
+        err = select_core_and_segment(dev, &offset);
+        if (likely(!err))
+                writew(value, bus->mmio + offset);
+        mmiowb();
+        spin_unlock_irqrestore(&bus->bar_lock, flags);
 }
 
 static void ssb_pcmcia_write32(struct ssb_device *dev, u16 offset, u32 value)
 {
         struct ssb_bus *bus = dev->bus;
+        unsigned long flags;
+        int err;
 
-        if (unlikely(select_core_and_segment(dev, &offset)))
-                return;
-        writeb((value & 0xFF000000) >> 24, bus->mmio + offset + 3);
-        writeb((value & 0x00FF0000) >> 16, bus->mmio + offset + 2);
-        writeb((value & 0x0000FF00) >> 8, bus->mmio + offset + 1);
-        writeb((value & 0x000000FF) >> 0, bus->mmio + offset + 0);
+        spin_lock_irqsave(&bus->bar_lock, flags);
+        err = select_core_and_segment(dev, &offset);
+        if (likely(!err)) {
+                writew((value & 0x0000FFFF), bus->mmio + offset);
+                writew(((value & 0xFFFF0000) >> 16), bus->mmio + offset + 2);
+        }
+        mmiowb();
+        spin_unlock_irqrestore(&bus->bar_lock, flags);
 }
 
 /* Not "static", as it's used in main.c */
@@ -231,10 +244,12 @@ const struct ssb_bus_ops ssb_pcmcia_ops = {
         .write32        = ssb_pcmcia_write32,
 };
 
+#include <linux/etherdevice.h>
 int ssb_pcmcia_get_invariants(struct ssb_bus *bus,
                               struct ssb_init_invariants *iv)
 {
         //TODO
+        random_ether_addr(iv->sprom.il0mac);
         return 0;
 }
 
diff --git a/include/linux/ssb/ssb.h b/include/linux/ssb/ssb.h
index 0eaa98424f0a..cacbae531945 100644
--- a/include/linux/ssb/ssb.h
+++ b/include/linux/ssb/ssb.h
@@ -231,7 +231,8 @@ struct ssb_bus {
         struct ssb_device *mapped_device;
         /* Currently mapped PCMCIA segment. (bustype == SSB_BUSTYPE_PCMCIA only) */
         u8 mapped_pcmcia_seg;
-        /* Lock for core and segment switching. */
+        /* Lock for core and segment switching.
+         * On PCMCIA-host busses this is used to protect the whole MMIO access. */
         spinlock_t bar_lock;
 
         /* The bus this backplane is running on. */