1 files changed, 103 insertions, 0 deletions
diff --git a/arch/mips/mti-sead3/sead3-pic32-bus.c b/arch/mips/mti-sead3/sead3-pic32-bus.c
new file mode 100644
index 000000000000..9f0d89bc800e
--- /dev/null
+++ b/arch/mips/mti-sead3/sead3-pic32-bus.c
@@ -0,0 +1,103 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
+ */
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/errno.h>
+
+#define PIC32_NULL	0x00
+#define PIC32_RD	0x01
+#define PIC32_SYSRD	0x02
+#define PIC32_WR	0x10
+#define PIC32_SYSWR	0x20
+#define PIC32_IRQ_CLR   0x40
+#define PIC32_STATUS	0x80
+
+#define DELAY()	udelay(100)	/* FIXME: needed? */
+
+/* spinlock to ensure atomic access to PIC32 */
+static DEFINE_SPINLOCK(pic32_bus_lock);
+
+/* FIXME: io_remap these */
+static void __iomem *bus_xfer   = (void __iomem *)0xbf000600;
+static void __iomem *bus_status = (void __iomem *)0xbf000060;
+
+static inline unsigned int ioready(void)
+{
+	return readl(bus_status) & 1;
+}
+
+static inline void wait_ioready(void)
+{
+	do { } while (!ioready());
+}
+
+static inline void wait_ioclear(void)
+{
+	do { } while (ioready());
+}
+
+static inline void check_ioclear(void)
+{
+	if (ioready()) {
+		pr_debug("ioclear: initially busy\n");
+		do {
+			(void) readl(bus_xfer);
+			DELAY();
+		} while (ioready());
+		pr_debug("ioclear: cleared busy\n");
+	}
+}
+
+u32 pic32_bus_readl(u32 reg)
+{
+	unsigned long flags;
+	u32 status, val;
+
+	spin_lock_irqsave(&pic32_bus_lock, flags);
+
+	check_ioclear();
+
+	writel((PIC32_RD << 24) | (reg & 0x00ffffff), bus_xfer);
+	DELAY();
+	wait_ioready();
+	status = readl(bus_xfer);
+	DELAY();
+	val = readl(bus_xfer);
+	wait_ioclear();
+
+	pr_debug("pic32_bus_readl: *%x -> %x (status=%x)\n", reg, val, status);
+
+	spin_unlock_irqrestore(&pic32_bus_lock, flags);
+
+	return val;
+}
+
+void pic32_bus_writel(u32 val, u32 reg)
+{
+	unsigned long flags;
+	u32 status;
+
+	spin_lock_irqsave(&pic32_bus_lock, flags);
+
+	check_ioclear();
+
+	writel((PIC32_WR << 24) | (reg & 0x00ffffff), bus_xfer);
+	DELAY();
+	writel(val, bus_xfer);
+	DELAY();
+	wait_ioready();
+	status = readl(bus_xfer);
+	wait_ioclear();
+
+	pr_debug("pic32_bus_writel: *%x <- %x (status=%x)\n", reg, val, status);
+
+	spin_unlock_irqrestore(&pic32_bus_lock, flags);
+}