[TC] TURBOchannel support for the DECstation

This is the platform-specific part of TURBOchannel bus support for the
DECstation.  It implements determining whether the bus is actually there,
getting bus parameters, IRQ assignments for devices and protected accesses
to possibly unoccupied slots that may trigger bus error exceptions.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 95 insertions, 0 deletions

diff --git a/arch/mips/dec/tc.c b/arch/mips/dec/tc.c
new file mode 100644
index 000000000000..732027c79834
--- /dev/null
+++ b/arch/mips/dec/tc.c
@@ -0,0 +1,95 @@
+/*
+ *      TURBOchannel architecture calls.
+ *
+ *      Copyright (c) Harald Koerfgen, 1998
+ *      Copyright (c) 2001, 2003, 2005, 2006  Maciej W. Rozycki
+ *      Copyright (c) 2005  James Simmons
+ *
+ *      This file is subject to the terms and conditions of the GNU
+ *      General Public License.  See the file "COPYING" in the main
+ *      directory of this archive for more details.
+ */
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/tc.h>
+#include <linux/types.h>
+
+#include <asm/addrspace.h>
+#include <asm/bootinfo.h>
+#include <asm/paccess.h>
+
+#include <asm/dec/interrupts.h>
+#include <asm/dec/prom.h>
+#include <asm/dec/system.h>
+
+/*
+ * Protected read byte from TURBOchannel slot space.
+ */
+int tc_preadb(u8 *valp, void __iomem *addr)
+{
+        return get_dbe(*valp, (u8 *)addr);
+}
+
+/*
+ * Get TURBOchannel bus information as specified by the spec, plus
+ * the slot space base address and the number of slots.
+ */
+int __init tc_bus_get_info(struct tc_bus *tbus)
+{
+        if (!dec_tc_bus)
+                return -ENXIO;
+
+        memcpy(&tbus->info, rex_gettcinfo(), sizeof(tbus->info));
+        tbus->slot_base = CPHYSADDR((long)rex_slot_address(0));
+
+        switch (mips_machtype) {
+        case MACH_DS5000_200:
+                tbus->num_tcslots = 7;
+                break;
+        case MACH_DS5000_2X0:
+        case MACH_DS5900:
+                tbus->ext_slot_base = 0x20000000;
+                tbus->ext_slot_size = 0x20000000;
+                /* fall through */
+        case MACH_DS5000_1XX:
+                tbus->num_tcslots = 3;
+                break;
+        case MACH_DS5000_XX:
+                tbus->num_tcslots = 2;
+        default:
+                break;
+        }
+        return 0;
+}
+
+/*
+ * Get the IRQ for the specified slot.
+ */
+void __init tc_device_get_irq(struct tc_dev *tdev)
+{
+        switch (tdev->slot) {
+        case 0:
+                tdev->interrupt = dec_interrupt[DEC_IRQ_TC0];
+                break;
+        case 1:
+                tdev->interrupt = dec_interrupt[DEC_IRQ_TC1];
+                break;
+        case 2:
+                tdev->interrupt = dec_interrupt[DEC_IRQ_TC2];
+                break;
+        /*
+         * Yuck! DS5000/200 onboard devices
+         */
+        case 5:
+                tdev->interrupt = dec_interrupt[DEC_IRQ_TC5];
+                break;
+        case 6:
+                tdev->interrupt = dec_interrupt[DEC_IRQ_TC6];
+                break;
+        default:
+                tdev->interrupt = -1;
+                break;
+        }
+}