MIPS: ath79: fix broken ar724x_pci_{read,write} functions

The current ar724x_pci_{read,write} functions are
broken. Due to that, pci_read_config_byte returns
with bogus values, and pci_write_config_{byte,word}
unconditionally clears the accessed PCI configuration
registers instead of changing the value of them.

The patch fixes the broken functions, thus the PCI
configuration space can be accessed correctly.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3493/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 26 insertions, 26 deletions

diff --git a/arch/mips/pci/pci-ar724x.c b/arch/mips/pci/pci-ar724x.c
index 342bf4ab8960..bb4f2162d4e4 100644
--- a/arch/mips/pci/pci-ar724x.c
+++ b/arch/mips/pci/pci-ar724x.c
@@ -22,8 +22,9 @@ static void __iomem *ar724x_pci_devcfg_base;
 static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
                             int size, uint32_t *value)
 {
-        unsigned long flags, addr, tval, mask;
+        unsigned long flags;
         void __iomem *base;
+        u32 data;
 
         if (devfn)
                 return PCIBIOS_DEVICE_NOT_FOUND;
@@ -31,24 +32,22 @@ static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
         base = ar724x_pci_devcfg_base;
 
         spin_lock_irqsave(&ar724x_pci_lock, flags);
+        data = __raw_readl(base + (where & ~3));
 
         switch (size) {
         case 1:
-                addr = where & ~3;
-                mask = 0xff000000 >> ((where % 4) * 8);
-                tval = __raw_readl(base + addr);
-                tval = tval & ~mask;
-                *value = (tval >> ((4 - (where % 4))*8));
+                if (where & 1)
+                        data >>= 8;
+                if (where & 2)
+                        data >>= 16;
+                data &= 0xff;
                 break;
         case 2:
-                addr = where & ~3;
-                mask = 0xffff0000 >> ((where % 4)*8);
-                tval = __raw_readl(base + addr);
-                tval = tval & ~mask;
-                *value = (tval >> ((4 - (where % 4))*8));
+                if (where & 2)
+                        data >>= 16;
+                data &= 0xffff;
                 break;
         case 4:
-                *value = __raw_readl(base + where);
                 break;
         default:
                 spin_unlock_irqrestore(&ar724x_pci_lock, flags);
@@ -57,6 +56,7 @@ static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
         }
 
         spin_unlock_irqrestore(&ar724x_pci_lock, flags);
+        *value = data;
 
         return PCIBIOS_SUCCESSFUL;
 }
@@ -64,8 +64,10 @@ static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
 static int ar724x_pci_write(struct pci_bus *bus, unsigned int devfn, int where,
                              int size, uint32_t value)
 {
-        unsigned long flags, tval, addr, mask;
+        unsigned long flags;
         void __iomem *base;
+        u32 data;
+        int s;
 
         if (devfn)
                 return PCIBIOS_DEVICE_NOT_FOUND;
@@ -73,26 +75,21 @@ static int ar724x_pci_write(struct pci_bus *bus, unsigned int devfn, int where,
         base = ar724x_pci_devcfg_base;
 
         spin_lock_irqsave(&ar724x_pci_lock, flags);
+        data = __raw_readl(base + (where & ~3));
 
         switch (size) {
         case 1:
-                addr = where & ~3;
-                mask = 0xff000000 >> ((where % 4)*8);
-                tval = __raw_readl(base + addr);
-                tval = tval & ~mask;
-                tval |= (value << ((4 - (where % 4))*8)) & mask;
-                __raw_writel(tval, base + addr);
+                s = ((where & 3) * 8);
+                data &= ~(0xff << s);
+                data |= ((value & 0xff) << s);
                 break;
         case 2:
-                addr = where & ~3;
-                mask = 0xffff0000 >> ((where % 4)*8);
-                tval = __raw_readl(base + addr);
-                tval = tval & ~mask;
-                tval |= (value << ((4 - (where % 4))*8)) & mask;
-                __raw_writel(tval, base + addr);
+                s = ((where & 2) * 8);
+                data &= ~(0xffff << s);
+                data |= ((value & 0xffff) << s);
                 break;
         case 4:
-                __raw_writel(value, (base + where));
+                data = value;
                 break;
         default:
                 spin_unlock_irqrestore(&ar724x_pci_lock, flags);
@@ -100,6 +97,9 @@ static int ar724x_pci_write(struct pci_bus *bus, unsigned int devfn, int where,
                 return PCIBIOS_BAD_REGISTER_NUMBER;
         }
 
+        __raw_writel(data, base + (where & ~3));
+        /* flush write */
+        __raw_readl(base + (where & ~3));
         spin_unlock_irqrestore(&ar724x_pci_lock, flags);
 
         return PCIBIOS_SUCCESSFUL;