MXC: Add support for ULPI Viewports

The ARC USB OTG Core has support for accessing ULPI tranceivers
through so called ULPI viewports. Export a set of function for use with
the USB OTG framework.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 113 insertions, 0 deletions

diff --git a/arch/arm/plat-mxc/ulpi.c b/arch/arm/plat-mxc/ulpi.c
new file mode 100644
index 00000000000..582c6dfaba4
--- /dev/null
+++ b/arch/arm/plat-mxc/ulpi.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2008 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
+ * Copyright 2009 Daniel Mack <daniel@caiaq.de>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA  02110-1301, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/usb/otg.h>
+
+#include <mach/ulpi.h>
+
+/* ULPIVIEW register bits */
+#define ULPIVW_WU		(1 << 31)	/* Wakeup */
+#define ULPIVW_RUN		(1 << 30)	/* read/write run */
+#define ULPIVW_WRITE		(1 << 29)	/* 0 = read  1 = write */
+#define ULPIVW_SS		(1 << 27)	/* SyncState */
+#define ULPIVW_PORT_MASK	0x07	/* Port field */
+#define ULPIVW_PORT_SHIFT	24
+#define ULPIVW_ADDR_MASK	0xff	/* data address field */
+#define ULPIVW_ADDR_SHIFT	16
+#define ULPIVW_RDATA_MASK	0xff	/* read data field */
+#define ULPIVW_RDATA_SHIFT	8
+#define ULPIVW_WDATA_MASK	0xff	/* write data field */
+#define ULPIVW_WDATA_SHIFT	0
+
+static int ulpi_poll(void __iomem *view, u32 bit)
+{
+	int timeout = 10000;
+
+	while (timeout--) {
+		u32 data = __raw_readl(view);
+
+		if (!(data & bit))
+			return 0;
+
+		cpu_relax();
+	};
+
+	printk(KERN_WARNING "timeout polling for ULPI device\n");
+
+	return -ETIMEDOUT;
+}
+
+static int ulpi_read(struct otg_transceiver *otg, u32 reg)
+{
+	int ret;
+	void __iomem *view = otg->io_priv;
+
+	/* make sure interface is running */
+	if (!(__raw_readl(view) & ULPIVW_SS)) {
+		__raw_writel(ULPIVW_WU, view);
+
+		/* wait for wakeup */
+		ret = ulpi_poll(view, ULPIVW_WU);
+		if (ret)
+			return ret;
+	}
+
+	/* read the register */
+	__raw_writel((ULPIVW_RUN | (reg << ULPIVW_ADDR_SHIFT)), view);
+
+	/* wait for completion */
+	ret = ulpi_poll(view, ULPIVW_RUN);
+	if (ret)
+		return ret;
+
+	return (__raw_readl(view) >> ULPIVW_RDATA_SHIFT) & ULPIVW_RDATA_MASK;
+}
+
+static int ulpi_write(struct otg_transceiver *otg, u32 val, u32 reg)
+{
+	int ret;
+	void __iomem *view = otg->io_priv;
+
+	/* make sure the interface is running */
+	if (!(__raw_readl(view) & ULPIVW_SS)) {
+		__raw_writel(ULPIVW_WU, view);
+		/* wait for wakeup */
+		ret = ulpi_poll(view, ULPIVW_WU);
+		if (ret)
+			return ret;
+	}
+
+	__raw_writel((ULPIVW_RUN | ULPIVW_WRITE |
+		      (reg << ULPIVW_ADDR_SHIFT) |
+		      ((val & ULPIVW_WDATA_MASK) << ULPIVW_WDATA_SHIFT)), view);
+
+	/* wait for completion */
+	return ulpi_poll(view, ULPIVW_RUN);
+}
+
+struct otg_io_access_ops mxc_ulpi_access_ops = {
+	.read	= ulpi_read,
+	.write	= ulpi_write,
+};
+EXPORT_SYMBOL_GPL(mxc_ulpi_access_ops);
+