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>

4 files changed, 124 insertions, 0 deletions

diff --git a/arch/arm/plat-mxc/Kconfig b/arch/arm/plat-mxc/Kconfig
index ca5c7c226341..e8e92cbd108c 100644
--- a/arch/arm/plat-mxc/Kconfig
+++ b/arch/arm/plat-mxc/Kconfig
@@ -69,6 +69,9 @@ config MXC_PWM
         help
           Enable support for the i.MX PWM controller(s).
 
+config MXC_ULPI
+        bool
+
 config ARCH_HAS_RNGA
         bool
         depends on ARCH_MXC
diff --git a/arch/arm/plat-mxc/Makefile b/arch/arm/plat-mxc/Makefile
index e3212c8ff421..545412f81831 100644
--- a/arch/arm/plat-mxc/Makefile
+++ b/arch/arm/plat-mxc/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_ARCH_MX1) += iomux-mx1-mx2.o dma-mx1-mx2.o
 obj-$(CONFIG_ARCH_MX2) += iomux-mx1-mx2.o dma-mx1-mx2.o
 obj-$(CONFIG_ARCH_MXC_IOMUX_V3) += iomux-v3.o
 obj-$(CONFIG_MXC_PWM)  += pwm.o
+obj-$(CONFIG_MXC_ULPI) += ulpi.o
diff --git a/arch/arm/plat-mxc/include/mach/ulpi.h b/arch/arm/plat-mxc/include/mach/ulpi.h
new file mode 100644
index 000000000000..96b6ab4c40c3
--- /dev/null
+++ b/arch/arm/plat-mxc/include/mach/ulpi.h
@@ -0,0 +1,7 @@
+#ifndef __MACH_ULPI_H
+#define __MACH_ULPI_H
+
+extern struct otg_io_access_ops mxc_ulpi_access_ops;
+
+#endif /* __MACH_ULPI_H */
+
diff --git a/arch/arm/plat-mxc/ulpi.c b/arch/arm/plat-mxc/ulpi.c
new file mode 100644
index 000000000000..582c6dfaba4a
--- /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);
+