usb: ulpi: Add omap-ulpi-view port support

Based on discussion from this thread [1].
Adding omap-view port that helps us in using the generic ulpi
framework for any ulpi phy ops using the INSNREG05_ULPI viewport
reg available on omap platform.

Currently ehci ports are available on omap3/4 platforms so enable the same
for beagle and panda, patch is tested on the same boards.

Thanks to Igor Grinberg <grinberg@compulab.co.il> for reviewing the
omap-ehci patches and suggesting this approach.

[1]: http://www.mail-archive.com/u-boot@lists.denx.de/msg76076.html

Tested-by: Stefano Babic <sbabic@denx.de>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>

doc/README.omap-ulpi-viewport

@@ -0,0 +1,27 @@
+Reference code ""drivers/usb/ulpi/omap-ulpi-viewport.c"
+
+Contains the ulpi read write api's to perform
+any ulpi phy port access on omap platform.
+
+On omap ehci reg map contains INSNREG05_ULPI
+register which offers the ulpi phy access so
+any ulpi phy commands should be passsed using this
+register.
+
+omap-ulpi-viewport.c is a low level function
+implementation of "drivers/usb/ulpi/ulpi.c"
+
+To enable and use omap-ulpi-viewport.c
+we require CONFIG_USB_ULPI_VIEWPORT_OMAP and
+CONFIG_USB_ULPI be enabled in config file.
+
+Any ulpi ops request can be done with ulpi.c
+and soc specific binding and usage is done with
+omap-ulpi-viewport implementation.
+
+Ex: scenario:
+omap-ehci driver code requests for ulpi phy reset if
+ehci is used in phy mode, which will call ulpi phy reset
+the ulpi phy reset does ulpi_read/write from viewport
+implementation which will do ulpi reset using the
+INSNREG05_ULPI register.

drivers/usb/ulpi/Makefile

@@ -24,6 +24,7 @@ LIB	:= $(obj)libusb_ulpi.o
 
 COBJS-$(CONFIG_USB_ULPI)		+= ulpi.o
 COBJS-$(CONFIG_USB_ULPI_VIEWPORT)	+= ulpi-viewport.o
+COBJS-$(CONFIG_USB_ULPI_VIEWPORT_OMAP)	+= omap-ulpi-viewport.o
 
 COBJS	:= $(COBJS-y)
 SRCS	:= $(COBJS:.o=.c)

drivers/usb/ulpi/omap-ulpi-viewport.c

@@ -0,0 +1,105 @@
+/*
+ * OMAP ulpi viewport support
+ * Based on drivers/usb/ulpi/ulpi-viewport.c
+ *
+ * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com
+ * Author: Govindraj R <govindraj.raja@ti.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2  of
+ * the License as published by the Free Software Foundation.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <usb/ulpi.h>
+
+#define OMAP_ULPI_WR_OPSEL	(3 << 21)
+#define OMAP_ULPI_ACCESS	(1 << 31)
+
+/*
+ * Wait for the ULPI Access to complete
+ */
+static int ulpi_wait(struct ulpi_viewport *ulpi_vp, u32 mask)
+{
+	int timeout = CONFIG_USB_ULPI_TIMEOUT;
+
+	while (--timeout) {
+		if ((readl(ulpi_vp->viewport_addr) & mask))
+			return 0;
+
+		udelay(1);
+	}
+
+	return ULPI_ERROR;
+}
+
+/*
+ * Wake the ULPI PHY up for communication
+ *
+ * returns 0 on success.
+ */
+static int ulpi_wakeup(struct ulpi_viewport *ulpi_vp)
+{
+	int err;
+
+	if (readl(ulpi_vp->viewport_addr) & OMAP_ULPI_ACCESS)
+		return 0; /* already awake */
+
+	writel(OMAP_ULPI_ACCESS, ulpi_vp->viewport_addr);
+
+	err = ulpi_wait(ulpi_vp, OMAP_ULPI_ACCESS);
+	if (err)
+		debug("ULPI wakeup timed out\n");
+
+	return err;
+}
+
+/*
+ * Issue a ULPI read/write request
+ */
+static int ulpi_request(struct ulpi_viewport *ulpi_vp, u32 value)
+{
+	int err;
+
+	err = ulpi_wakeup(ulpi_vp);
+	if (err)
+		return err;
+
+	writel(value, ulpi_vp->viewport_addr);
+
+	err = ulpi_wait(ulpi_vp, OMAP_ULPI_ACCESS);
+	if (err)
+		debug("ULPI request timed out\n");
+
+	return err;
+}
+
+int ulpi_write(struct ulpi_viewport *ulpi_vp, u8 *reg, u32 value)
+{
+	u32 val = ((ulpi_vp->port_num & 0xf) << 24) |
+			OMAP_ULPI_WR_OPSEL | ((u32)reg << 16) | (value & 0xff);
+
+	return ulpi_request(ulpi_vp, val);
+}
+
+u32 ulpi_read(struct ulpi_viewport *ulpi_vp, u8 *reg)
+{
+	int err;
+	u32 val = ((ulpi_vp->port_num & 0xf) << 24) |
+			 OMAP_ULPI_WR_OPSEL | ((u32)reg << 16);
+
+	err = ulpi_request(ulpi_vp, val);
+	if (err)
+		return err;
+
+	return readl(ulpi_vp->viewport_addr) & 0xff;
+}

include/configs/omap3_beagle.h

@@ -129,6 +129,10 @@
 /* USB EHCI */
 #define CONFIG_CMD_USB
 #define CONFIG_USB_EHCI
+
+#define CONFIG_USB_ULPI
+#define CONFIG_USB_ULPI_VIEWPORT_OMAP
+
 #define CONFIG_SYS_USB_EHCI_MAX_ROOT_PORTS 3
 #define CONFIG_USB_HOST_ETHER
 #define CONFIG_USB_ETHER_SMSC95XX

include/configs/omap4_panda.h

@@ -33,6 +33,9 @@
  */
 #define CONFIG_PANDA		1	/* working with Panda */
 
+#define CONFIG_USB_ULPI
+#define CONFIG_USB_ULPI_VIEWPORT_OMAP
+
 #include <configs/omap4_common.h>
 
 /* GPIO */