usb: omap1: OTG controller driver

Transceivers need to manage OTG controller state on OMAP1 to enable
switching between peripheral and host modes. Provide a driver for that.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Felipe Balbi <balbi@ti.com>

3 files changed, 180 insertions, 0 deletions

diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 921a9f43e309..0dbab6f5c2d4 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -142,6 +142,16 @@ config USB_GPIO_VBUS
           optionally control of a D+ pullup GPIO as well as a VBUS
           current limit regulator.
 
+config OMAP_OTG
+        tristate "OMAP USB OTG controller driver"
+        depends on ARCH_OMAP_OTG && EXTCON
+        help
+          Enable this to support some transceivers on OMAP1 platforms. OTG
+          controller is needed to switch between host and peripheral modes.
+
+          This driver can also be built as a module. If so, the module
+          will be called omap-otg.
+
 config USB_ISP1301
         tristate "NXP ISP1301 USB transceiver support"
         depends on USB || USB_GADGET
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index 1bf6c083a36e..64a9345e5633 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_NOP_USB_XCEIV)		+= phy-generic.o
 obj-$(CONFIG_OMAP_CONTROL_USB)          += phy-omap-control.o
 obj-$(CONFIG_AM335X_CONTROL_USB)        += phy-am335x-control.o
 obj-$(CONFIG_AM335X_PHY_USB)            += phy-am335x.o
+obj-$(CONFIG_OMAP_OTG)                  += phy-omap-otg.o
 obj-$(CONFIG_OMAP_USB3)                 += phy-omap-usb3.o
 obj-$(CONFIG_SAMSUNG_USBPHY)            += phy-samsung-usb.o
 obj-$(CONFIG_SAMSUNG_USB2PHY)           += phy-samsung-usb2.o
diff --git a/drivers/usb/phy/phy-omap-otg.c b/drivers/usb/phy/phy-omap-otg.c
new file mode 100644
index 000000000000..11598cdb3189
--- /dev/null
+++ b/drivers/usb/phy/phy-omap-otg.c
@@ -0,0 +1,169 @@
+/*
+ * OMAP OTG controller driver
+ *
+ * Based on code from tahvo-usb.c and isp1301_omap.c drivers.
+ *
+ * Copyright (C) 2005-2006 Nokia Corporation
+ * Copyright (C) 2004 Texas Instruments
+ * Copyright (C) 2004 David Brownell
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/extcon.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/usb-omap1.h>
+
+struct otg_device {
+        void __iomem                    *base;
+        bool                            id;
+        bool                            vbus;
+        struct extcon_specific_cable_nb vbus_dev;
+        struct extcon_specific_cable_nb id_dev;
+        struct notifier_block           vbus_nb;
+        struct notifier_block           id_nb;
+};
+
+#define OMAP_OTG_CTRL           0x0c
+#define OMAP_OTG_ASESSVLD       (1 << 20)
+#define OMAP_OTG_BSESSEND       (1 << 19)
+#define OMAP_OTG_BSESSVLD       (1 << 18)
+#define OMAP_OTG_VBUSVLD        (1 << 17)
+#define OMAP_OTG_ID             (1 << 16)
+#define OMAP_OTG_XCEIV_OUTPUTS \
+        (OMAP_OTG_ASESSVLD | OMAP_OTG_BSESSEND | OMAP_OTG_BSESSVLD | \
+         OMAP_OTG_VBUSVLD  | OMAP_OTG_ID)
+
+static void omap_otg_ctrl(struct otg_device *otg_dev, u32 outputs)
+{
+        u32 l;
+
+        l = readl(otg_dev->base + OMAP_OTG_CTRL);
+        l &= ~OMAP_OTG_XCEIV_OUTPUTS;
+        l |= outputs;
+        writel(l, otg_dev->base + OMAP_OTG_CTRL);
+}
+
+static void omap_otg_set_mode(struct otg_device *otg_dev)
+{
+        if (!otg_dev->id && otg_dev->vbus)
+                /* Set B-session valid. */
+                omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSVLD);
+        else if (otg_dev->vbus)
+                /* Set A-session valid. */
+                omap_otg_ctrl(otg_dev, OMAP_OTG_ASESSVLD);
+        else if (!otg_dev->id)
+                /* Set B-session end to indicate no VBUS. */
+                omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSEND);
+}
+
+static int omap_otg_id_notifier(struct notifier_block *nb,
+                                unsigned long event, void *ptr)
+{
+        struct otg_device *otg_dev = container_of(nb, struct otg_device, id_nb);
+
+        otg_dev->id = event;
+        omap_otg_set_mode(otg_dev);
+
+        return NOTIFY_DONE;
+}
+
+static int omap_otg_vbus_notifier(struct notifier_block *nb,
+                                  unsigned long event, void *ptr)
+{
+        struct otg_device *otg_dev = container_of(nb, struct otg_device,
+                                                  vbus_nb);
+
+        otg_dev->vbus = event;
+        omap_otg_set_mode(otg_dev);
+
+        return NOTIFY_DONE;
+}
+
+static int omap_otg_probe(struct platform_device *pdev)
+{
+        const struct omap_usb_config *config = pdev->dev.platform_data;
+        struct otg_device *otg_dev;
+        struct extcon_dev *extcon;
+        int ret;
+        u32 rev;
+
+        if (!config || !config->extcon)
+                return -ENODEV;
+
+        extcon = extcon_get_extcon_dev(config->extcon);
+        if (!extcon)
+                return -EPROBE_DEFER;
+
+        otg_dev = devm_kzalloc(&pdev->dev, sizeof(*otg_dev), GFP_KERNEL);
+        if (!otg_dev)
+                return -ENOMEM;
+
+        otg_dev->base = devm_ioremap_resource(&pdev->dev, &pdev->resource[0]);
+        if (IS_ERR(otg_dev->base))
+                return PTR_ERR(otg_dev->base);
+
+        otg_dev->id_nb.notifier_call = omap_otg_id_notifier;
+        otg_dev->vbus_nb.notifier_call = omap_otg_vbus_notifier;
+
+        ret = extcon_register_interest(&otg_dev->id_dev, config->extcon,
+                                       "USB-HOST", &otg_dev->id_nb);
+        if (ret)
+                return ret;
+
+        ret = extcon_register_interest(&otg_dev->vbus_dev, config->extcon,
+                                       "USB", &otg_dev->vbus_nb);
+        if (ret) {
+                extcon_unregister_interest(&otg_dev->id_dev);
+                return ret;
+        }
+
+        otg_dev->id = extcon_get_cable_state(extcon, "USB-HOST");
+        otg_dev->vbus = extcon_get_cable_state(extcon, "USB");
+        omap_otg_set_mode(otg_dev);
+
+        rev = readl(otg_dev->base);
+
+        dev_info(&pdev->dev,
+                 "OMAP USB OTG controller rev %d.%d (%s, id=%d, vbus=%d)\n",
+                 (rev >> 4) & 0xf, rev & 0xf, config->extcon, otg_dev->id,
+                 otg_dev->vbus);
+
+        return 0;
+}
+
+static int omap_otg_remove(struct platform_device *pdev)
+{
+        struct otg_device *otg_dev = platform_get_drvdata(pdev);
+
+        extcon_unregister_interest(&otg_dev->id_dev);
+        extcon_unregister_interest(&otg_dev->vbus_dev);
+
+        return 0;
+}
+
+static struct platform_driver omap_otg_driver = {
+        .probe          = omap_otg_probe,
+        .remove         = omap_otg_remove,
+        .driver         = {
+                .owner  = THIS_MODULE,
+                .name   = "omap_otg",
+        },
+};
+module_platform_driver(omap_otg_driver);
+
+MODULE_DESCRIPTION("OMAP USB OTG controller driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");