USB OTG: Add generic driver for ULPI OTG transceiver

This adds a minimal generic driver for ULPI connected transceivers,
using the OTG framework functions recently introduced.

The driver got a table to match the ULPI chips, which currently only has
one entry for NXP's ISP 1504 transceiver.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Heikki Krogerus <ext-heikki.krogerus@nokia.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 146 insertions, 0 deletions

diff --git a/drivers/usb/otg/Kconfig b/drivers/usb/otg/Kconfig
index aa884d072f0b..de56b3d743d7 100644
--- a/drivers/usb/otg/Kconfig
+++ b/drivers/usb/otg/Kconfig
@@ -41,6 +41,15 @@ config ISP1301_OMAP
           This driver can also be built as a module.  If so, the module
           will be called isp1301_omap.
 
+config USB_ULPI
+        bool "Generic ULPI Transceiver Driver"
+        depends on ARM
+        help
+          Enable this to support ULPI connected USB OTG transceivers which
+          are likely found on embedded boards.
+
+          The only chip currently supported is NXP's ISP1504
+
 config TWL4030_USB
         tristate "TWL4030 USB Transceiver Driver"
         depends on TWL4030_CORE && REGULATOR_TWL4030
diff --git a/drivers/usb/otg/Makefile b/drivers/usb/otg/Makefile
index 208167856529..aeb49a8ec412 100644
--- a/drivers/usb/otg/Makefile
+++ b/drivers/usb/otg/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_USB_GPIO_VBUS)	+= gpio_vbus.o
 obj-$(CONFIG_ISP1301_OMAP)      += isp1301_omap.o
 obj-$(CONFIG_TWL4030_USB)       += twl4030-usb.o
 obj-$(CONFIG_NOP_USB_XCEIV)     += nop-usb-xceiv.o
+obj-$(CONFIG_USB_ULPI)          += ulpi.o
 
 ccflags-$(CONFIG_USB_DEBUG)     += -DDEBUG
 ccflags-$(CONFIG_USB_GADGET_DEBUG) += -DDEBUG
diff --git a/drivers/usb/otg/ulpi.c b/drivers/usb/otg/ulpi.c
new file mode 100644
index 000000000000..896527456b7e
--- /dev/null
+++ b/drivers/usb/otg/ulpi.c
@@ -0,0 +1,136 @@
+/*
+ * Generic ULPI USB transceiver support
+ *
+ * Copyright (C) 2009 Daniel Mack <daniel@caiaq.de>
+ *
+ * Based on sources from
+ *
+ *   Sascha Hauer <s.hauer@pengutronix.de>
+ *   Freescale Semiconductors
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/usb.h>
+#include <linux/usb/otg.h>
+#include <linux/usb/ulpi.h>
+
+/* ULPI register addresses */
+#define ULPI_VID_LOW         0x00    /* Vendor ID low */
+#define ULPI_VID_HIGH        0x01    /* Vendor ID high */
+#define ULPI_PID_LOW         0x02    /* Product ID low */
+#define ULPI_PID_HIGH        0x03    /* Product ID high */
+#define ULPI_ITFCTL          0x07    /* Interface Control */
+#define ULPI_OTGCTL          0x0A    /* OTG Control */
+
+/* add to above register address to access Set/Clear functions */
+#define ULPI_REG_SET         0x01
+#define ULPI_REG_CLEAR       0x02
+
+/* ULPI OTG Control Register bits */
+#define ID_PULL_UP              (1 << 0)        /* enable ID Pull Up */
+#define DP_PULL_DOWN            (1 << 1)        /* enable DP Pull Down */
+#define DM_PULL_DOWN            (1 << 2)        /* enable DM Pull Down */
+#define DISCHRG_VBUS            (1 << 3)        /* Discharge Vbus */
+#define CHRG_VBUS               (1 << 4)        /* Charge Vbus */
+#define DRV_VBUS                (1 << 5)        /* Drive Vbus */
+#define DRV_VBUS_EXT            (1 << 6)        /* Drive Vbus external */
+#define USE_EXT_VBUS_IND        (1 << 7)        /* Use ext. Vbus indicator */
+
+#define ULPI_ID(vendor, product) (((vendor) << 16) | (product))
+
+#define TR_FLAG(flags, a, b)    (((flags) & a) ? b : 0)
+
+/* ULPI hardcoded IDs, used for probing */
+static unsigned int ulpi_ids[] = {
+        ULPI_ID(0x04cc, 0x1504),        /* NXP ISP1504 */
+};
+
+static int ulpi_set_flags(struct otg_transceiver *otg)
+{
+        unsigned int flags = 0;
+
+        if (otg->flags & USB_OTG_PULLUP_ID)
+                flags |= ID_PULL_UP;
+
+        if (otg->flags & USB_OTG_PULLDOWN_DM)
+                flags |= DM_PULL_DOWN;
+
+        if (otg->flags & USB_OTG_PULLDOWN_DP)
+                flags |= DP_PULL_DOWN;
+
+        if (otg->flags & USB_OTG_EXT_VBUS_INDICATOR)
+                flags |= USE_EXT_VBUS_IND;
+
+        return otg_io_write(otg, flags, ULPI_OTGCTL + ULPI_REG_SET);
+}
+
+static int ulpi_init(struct otg_transceiver *otg)
+{
+        int i, vid, pid;
+
+        vid = (otg_io_read(otg, ULPI_VID_HIGH) << 8) |
+               otg_io_read(otg, ULPI_VID_LOW);
+        pid = (otg_io_read(otg, ULPI_PID_HIGH) << 8) |
+               otg_io_read(otg, ULPI_PID_LOW);
+
+        pr_info("ULPI transceiver vendor/product ID 0x%04x/0x%04x\n", vid, pid);
+
+        for (i = 0; i < ARRAY_SIZE(ulpi_ids); i++)
+                if (ulpi_ids[i] == ULPI_ID(vid, pid))
+                        return ulpi_set_flags(otg);
+
+        pr_err("ULPI ID does not match any known transceiver.\n");
+        return -ENODEV;
+}
+
+static int ulpi_set_vbus(struct otg_transceiver *otg, bool on)
+{
+        unsigned int flags = otg_io_read(otg, ULPI_OTGCTL);
+
+        flags &= ~(DRV_VBUS | DRV_VBUS_EXT);
+
+        if (on) {
+                if (otg->flags & USB_OTG_DRV_VBUS)
+                        flags |= DRV_VBUS;
+
+                if (otg->flags & USB_OTG_DRV_VBUS_EXT)
+                        flags |= DRV_VBUS_EXT;
+        }
+
+        return otg_io_write(otg, flags, ULPI_OTGCTL + ULPI_REG_SET);
+}
+
+struct otg_transceiver *
+otg_ulpi_create(struct otg_io_access_ops *ops,
+                unsigned int flags)
+{
+        struct otg_transceiver *otg;
+
+        otg = kzalloc(sizeof(*otg), GFP_KERNEL);
+        if (!otg)
+                return NULL;
+
+        otg->label      = "ULPI";
+        otg->flags      = flags;
+        otg->io_ops     = ops;
+        otg->init       = ulpi_init;
+        otg->set_vbus   = ulpi_set_vbus;
+
+        return otg;
+}
+EXPORT_SYMBOL_GPL(otg_ulpi_create);
+