1 files changed, 79 insertions, 0 deletions
diff --git a/arch/sh/drivers/pci/ops-dreamcast.c b/arch/sh/drivers/pci/ops-dreamcast.c
new file mode 100644
index 000000000..517a8a970
--- /dev/null
+++ b/arch/sh/drivers/pci/ops-dreamcast.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI operations for the Sega Dreamcast
+ *
+ * Copyright (C) 2001, 2002  M. R. Brown
+ * Copyright (C) 2002, 2003  Paul Mundt
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/pci.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <mach/pci.h>
+
+/*
+ * The !gapspci_config_access case really shouldn't happen, ever, unless
+ * someone implicitly messes around with the last devfn value.. otherwise we
+ * only support a single device anyways, and if we didn't have a BBA, we
+ * wouldn't make it terribly far through the PCI setup anyways.
+ *
+ * Also, we could very easily support both Type 0 and Type 1 configurations
+ * here, but since it doesn't seem that there is any such implementation in
+ * existence, we don't bother.
+ *
+ * I suppose if someone actually gets around to ripping the chip out of
+ * the BBA and hanging some more devices off of it, then this might be
+ * something to take into consideration. However, due to the cost of the BBA,
+ * and the general lack of activity by DC hardware hackers, this doesn't seem
+ * likely to happen anytime soon.
+ */
+static int gapspci_config_access(unsigned char bus, unsigned int devfn)
+{
+	return (bus == 0) && (devfn == 0);
+}
+
+/*
+ * We can also actually read and write in b/w/l sizes! Thankfully this part
+ * was at least done right, and we don't have to do the stupid masking and
+ * shifting that we do on the 7751! Small wonders never cease to amaze.
+ */
+static int gapspci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
+{
+	*val = 0xffffffff;
+
+	if (!gapspci_config_access(bus->number, devfn))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	switch (size) {
+	case 1: *val = inb(GAPSPCI_BBA_CONFIG+where); break;
+	case 2: *val = inw(GAPSPCI_BBA_CONFIG+where); break;
+	case 4: *val = inl(GAPSPCI_BBA_CONFIG+where); break;
+	}
+
+        return PCIBIOS_SUCCESSFUL;
+}
+
+static int gapspci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
+{
+	if (!gapspci_config_access(bus->number, devfn))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	switch (size) {
+	case 1: outb(( u8)val, GAPSPCI_BBA_CONFIG+where); break;
+	case 2: outw((u16)val, GAPSPCI_BBA_CONFIG+where); break;
+	case 4: outl((u32)val, GAPSPCI_BBA_CONFIG+where); break;
+	}
+
+        return PCIBIOS_SUCCESSFUL;
+}
+
+struct pci_ops gapspci_pci_ops = {
+	.read	= gapspci_read,
+	.write	= gapspci_write,
+};