USB: EHCI Debug Port Device Gadget
This is a patch that implements an USB EHCI Debug Device using the
Gadget API. This patch applies to a 2.6.35-rc3 kernel.
The gadget needs a compliant usb controller that forwards the
USB_DEVICE_DEBUG_MODE feature to its gadget.
The gadget provides two configuration modes, one that only printk() the
received data, and one that exposes a serial device to userland
(/dev/ttyGSxxx).
The gadget has been tested on an IGEPv2 board running a 2.6.35-rc1
kernel. The debug port was fed on the host side by a 2.6.34 kernel.
Signed-off-by: Stephane Duverger <stephane.duverger@gmail.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index dd3b251..cd27f9b 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -915,6 +915,34 @@
Say "y" to link the driver statically, or "m" to build a
dynamically linked module called "g_hid".
+config USB_G_DBGP
+ tristate "EHCI Debug Device Gadget"
+ help
+ This gadget emulates an EHCI Debug device. This is useful when you want
+ to interact with an EHCI Debug Port.
+
+ Say "y" to link the driver statically, or "m" to build a
+ dynamically linked module called "g_dbgp".
+
+if USB_G_DBGP
+choice
+ prompt "EHCI Debug Device mode"
+ default USB_G_DBGP_SERIAL
+
+config USB_G_DBGP_PRINTK
+ depends on USB_G_DBGP
+ bool "printk"
+ help
+ Directly printk() received data. No interaction.
+
+config USB_G_DBGP_SERIAL
+ depends on USB_G_DBGP
+ bool "serial"
+ help
+ Userland can interact using /dev/ttyGSxxx.
+endchoice
+endif
+
# put drivers that need isochronous transfer support (for audio
# or video class gadget drivers), or specific hardware, here.
config USB_G_WEBCAM
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index 9bcde11..397b892 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -44,6 +44,7 @@
g_cdc-objs := cdc2.o
g_multi-objs := multi.o
g_hid-objs := hid.o
+g_dbgp-objs := dbgp.o
g_nokia-objs := nokia.o
g_webcam-objs := webcam.o
@@ -60,6 +61,7 @@
obj-$(CONFIG_USB_MIDI_GADGET) += g_midi.o
obj-$(CONFIG_USB_CDC_COMPOSITE) += g_cdc.o
obj-$(CONFIG_USB_G_HID) += g_hid.o
+obj-$(CONFIG_USB_G_DBGP) += g_dbgp.o
obj-$(CONFIG_USB_G_MULTI) += g_multi.o
obj-$(CONFIG_USB_G_NOKIA) += g_nokia.o
obj-$(CONFIG_USB_G_WEBCAM) += g_webcam.o
diff --git a/drivers/usb/gadget/dbgp.c b/drivers/usb/gadget/dbgp.c
new file mode 100644
index 0000000..0ed50a2
--- /dev/null
+++ b/drivers/usb/gadget/dbgp.c
@@ -0,0 +1,434 @@
+/*
+ * dbgp.c -- EHCI Debug Port device gadget
+ *
+ * Copyright (C) 2010 Stephane Duverger
+ *
+ * Released under the GPLv2.
+ *
+ */
+
+/* verbose messages */
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+
+/* See comments in "zero.c" */
+#include "epautoconf.c"
+
+#ifdef CONFIG_USB_G_DBGP_SERIAL
+#include "u_serial.c"
+#endif
+
+#define DRIVER_VENDOR_ID 0x0525 /* NetChip */
+#define DRIVER_PRODUCT_ID 0xc0de /* undefined */
+
+#define USB_DEBUG_MAX_PACKET_SIZE 8
+#define DBGP_REQ_EP0_LEN 128
+#define DBGP_REQ_LEN 512
+
+static struct dbgp {
+ struct usb_gadget *gadget;
+ struct usb_request *req;
+ struct usb_ep *i_ep;
+ struct usb_ep *o_ep;
+#ifdef CONFIG_USB_G_DBGP_SERIAL
+ struct gserial *serial;
+#endif
+} dbgp;
+
+static struct usb_device_descriptor device_desc = {
+ .bLength = sizeof device_desc,
+ .bDescriptorType = USB_DT_DEVICE,
+ .bcdUSB = __constant_cpu_to_le16(0x0200),
+ .bDeviceClass = USB_CLASS_VENDOR_SPEC,
+ .idVendor = __constant_cpu_to_le16(DRIVER_VENDOR_ID),
+ .idProduct = __constant_cpu_to_le16(DRIVER_PRODUCT_ID),
+ .bNumConfigurations = 1,
+};
+
+static struct usb_debug_descriptor dbg_desc = {
+ .bLength = sizeof dbg_desc,
+ .bDescriptorType = USB_DT_DEBUG,
+};
+
+static struct usb_endpoint_descriptor i_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .bEndpointAddress = USB_DIR_IN,
+};
+
+static struct usb_endpoint_descriptor o_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .bEndpointAddress = USB_DIR_OUT,
+};
+
+#ifdef CONFIG_USB_G_DBGP_PRINTK
+static int dbgp_consume(char *buf, unsigned len)
+{
+ char c;
+
+ if (!len)
+ return 0;
+
+ c = buf[len-1];
+ if (c != 0)
+ buf[len-1] = 0;
+
+ printk(KERN_NOTICE "%s%c", buf, c);
+ return 0;
+}
+
+static void __disable_ep(struct usb_ep *ep)
+{
+ if (ep && ep->driver_data == dbgp.gadget) {
+ usb_ep_disable(ep);
+ ep->driver_data = NULL;
+ }
+}
+
+static void dbgp_disable_ep(void)
+{
+ __disable_ep(dbgp.i_ep);
+ __disable_ep(dbgp.o_ep);
+}
+
+static void dbgp_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ int stp;
+ int err = 0;
+ int status = req->status;
+
+ if (ep == dbgp.i_ep) {
+ stp = 1;
+ goto fail;
+ }
+
+ if (status != 0) {
+ stp = 2;
+ goto release_req;
+ }
+
+ dbgp_consume(req->buf, req->actual);
+
+ req->length = DBGP_REQ_LEN;
+ err = usb_ep_queue(ep, req, GFP_ATOMIC);
+ if (err < 0) {
+ stp = 3;
+ goto release_req;
+ }
+
+ return;
+
+release_req:
+ kfree(req->buf);
+ usb_ep_free_request(dbgp.o_ep, req);
+ dbgp_disable_ep();
+fail:
+ dev_dbg(&dbgp.gadget->dev,
+ "complete: failure (%d:%d) ==> %d\n", stp, err, status);
+}
+
+static int dbgp_enable_ep_req(struct usb_ep *ep)
+{
+ int err, stp;
+ struct usb_request *req;
+
+ req = usb_ep_alloc_request(ep, GFP_KERNEL);
+ if (!req) {
+ err = -ENOMEM;
+ stp = 1;
+ goto fail_1;
+ }
+
+ req->buf = kmalloc(DBGP_REQ_LEN, GFP_KERNEL);
+ if (!req->buf) {
+ err = -ENOMEM;
+ stp = 2;
+ goto fail_2;
+ }
+
+ req->complete = dbgp_complete;
+ req->length = DBGP_REQ_LEN;
+ err = usb_ep_queue(ep, req, GFP_ATOMIC);
+ if (err < 0) {
+ stp = 3;
+ goto fail_3;
+ }
+
+ return 0;
+
+fail_3:
+ kfree(req->buf);
+fail_2:
+ usb_ep_free_request(dbgp.o_ep, req);
+fail_1:
+ dev_dbg(&dbgp.gadget->dev,
+ "enable ep req: failure (%d:%d)\n", stp, err);
+ return err;
+}
+
+static int __enable_ep(struct usb_ep *ep, struct usb_endpoint_descriptor *desc)
+{
+ int err = usb_ep_enable(ep, desc);
+ ep->driver_data = dbgp.gadget;
+ return err;
+}
+
+static int dbgp_enable_ep(void)
+{
+ int err, stp;
+
+ err = __enable_ep(dbgp.i_ep, &i_desc);
+ if (err < 0) {
+ stp = 1;
+ goto fail_1;
+ }
+
+ err = __enable_ep(dbgp.o_ep, &o_desc);
+ if (err < 0) {
+ stp = 2;
+ goto fail_2;
+ }
+
+ err = dbgp_enable_ep_req(dbgp.o_ep);
+ if (err < 0) {
+ stp = 3;
+ goto fail_3;
+ }
+
+ return 0;
+
+fail_3:
+ __disable_ep(dbgp.o_ep);
+fail_2:
+ __disable_ep(dbgp.i_ep);
+fail_1:
+ dev_dbg(&dbgp.gadget->dev, "enable ep: failure (%d:%d)\n", stp, err);
+ return err;
+}
+#endif
+
+static void dbgp_disconnect(struct usb_gadget *gadget)
+{
+#ifdef CONFIG_USB_G_DBGP_PRINTK
+ dbgp_disable_ep();
+#else
+ gserial_disconnect(dbgp.serial);
+#endif
+}
+
+static void dbgp_unbind(struct usb_gadget *gadget)
+{
+#ifdef CONFIG_USB_G_DBGP_SERIAL
+ kfree(dbgp.serial);
+#endif
+ if (dbgp.req) {
+ kfree(dbgp.req->buf);
+ usb_ep_free_request(gadget->ep0, dbgp.req);
+ }
+
+ gadget->ep0->driver_data = NULL;
+}
+
+static int __init dbgp_configure_endpoints(struct usb_gadget *gadget)
+{
+ int stp;
+
+ usb_ep_autoconfig_reset(gadget);
+
+ dbgp.i_ep = usb_ep_autoconfig(gadget, &i_desc);
+ if (!dbgp.i_ep) {
+ stp = 1;
+ goto fail_1;
+ }
+
+ dbgp.i_ep->driver_data = gadget;
+ i_desc.wMaxPacketSize =
+ __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE);
+
+ dbgp.o_ep = usb_ep_autoconfig(gadget, &o_desc);
+ if (!dbgp.o_ep) {
+ dbgp.i_ep->driver_data = NULL;
+ stp = 2;
+ goto fail_2;
+ }
+
+ dbgp.o_ep->driver_data = gadget;
+ o_desc.wMaxPacketSize =
+ __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE);
+
+ dbg_desc.bDebugInEndpoint = i_desc.bEndpointAddress & 0x7f;
+ dbg_desc.bDebugOutEndpoint = o_desc.bEndpointAddress & 0x7f;
+
+#ifdef CONFIG_USB_G_DBGP_SERIAL
+ dbgp.serial->in = dbgp.i_ep;
+ dbgp.serial->out = dbgp.o_ep;
+
+ dbgp.serial->in_desc = &i_desc;
+ dbgp.serial->out_desc = &o_desc;
+
+ if (gserial_setup(gadget, 1) < 0) {
+ stp = 3;
+ goto fail_3;
+ }
+
+ return 0;
+
+fail_3:
+ dbgp.o_ep->driver_data = NULL;
+#else
+ return 0;
+#endif
+fail_2:
+ dbgp.i_ep->driver_data = NULL;
+fail_1:
+ dev_dbg(&dbgp.gadget->dev, "ep config: failure (%d)\n", stp);
+ return -ENODEV;
+}
+
+static int __init dbgp_bind(struct usb_gadget *gadget)
+{
+ int err, stp;
+
+ dbgp.gadget = gadget;
+
+ dbgp.req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
+ if (!dbgp.req) {
+ err = -ENOMEM;
+ stp = 1;
+ goto fail;
+ }
+
+ dbgp.req->buf = kmalloc(DBGP_REQ_EP0_LEN, GFP_KERNEL);
+ if (!dbgp.req->buf) {
+ err = -ENOMEM;
+ stp = 2;
+ goto fail;
+ }
+
+ dbgp.req->length = DBGP_REQ_EP0_LEN;
+ gadget->ep0->driver_data = gadget;
+
+#ifdef CONFIG_USB_G_DBGP_SERIAL
+ dbgp.serial = kzalloc(sizeof(struct gserial), GFP_KERNEL);
+ if (!dbgp.serial) {
+ stp = 3;
+ err = -ENOMEM;
+ goto fail;
+ }
+#endif
+ err = dbgp_configure_endpoints(gadget);
+ if (err < 0) {
+ stp = 4;
+ goto fail;
+ }
+
+ dev_dbg(&dbgp.gadget->dev, "bind: success\n");
+ return 0;
+
+fail:
+ dev_dbg(&gadget->dev, "bind: failure (%d:%d)\n", stp, err);
+ dbgp_unbind(gadget);
+ return err;
+}
+
+static void dbgp_setup_complete(struct usb_ep *ep,
+ struct usb_request *req)
+{
+ dev_dbg(&dbgp.gadget->dev, "setup complete: %d, %d/%d\n",
+ req->status, req->actual, req->length);
+}
+
+static int dbgp_setup(struct usb_gadget *gadget,
+ const struct usb_ctrlrequest *ctrl)
+{
+ struct usb_request *req = dbgp.req;
+ u8 request = ctrl->bRequest;
+ u16 value = le16_to_cpu(ctrl->wValue);
+ u16 length = le16_to_cpu(ctrl->wLength);
+ int err = 0;
+ void *data;
+ u16 len;
+
+ gadget->ep0->driver_data = gadget;
+
+ if (request == USB_REQ_GET_DESCRIPTOR) {
+ switch (value>>8) {
+ case USB_DT_DEVICE:
+ dev_dbg(&dbgp.gadget->dev, "setup: desc device\n");
+ len = sizeof device_desc;
+ data = &device_desc;
+ break;
+ case USB_DT_DEBUG:
+ dev_dbg(&dbgp.gadget->dev, "setup: desc debug\n");
+ len = sizeof dbg_desc;
+ data = &dbg_desc;
+ break;
+ default:
+ goto fail;
+ }
+ } else if (request == USB_REQ_SET_FEATURE &&
+ value == USB_DEVICE_DEBUG_MODE) {
+ len = 0;
+ data = NULL;
+ dev_dbg(&dbgp.gadget->dev, "setup: feat debug\n");
+#ifdef CONFIG_USB_G_DBGP_PRINTK
+ err = dbgp_enable_ep();
+#else
+ err = gserial_connect(dbgp.serial, 0);
+#endif
+ if (err < 0)
+ goto fail;
+ } else
+ goto fail;
+
+ if (len >= 0) {
+ req->length = min(length, len);
+ req->zero = len < req->length;
+ if (data && req->length)
+ memcpy(req->buf, data, req->length);
+
+ req->complete = dbgp_setup_complete;
+ return usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
+ }
+
+fail:
+ dev_dbg(&dbgp.gadget->dev,
+ "setup: failure req %x v %x\n", request, value);
+ return err;
+}
+
+static struct usb_gadget_driver dbgp_driver = {
+ .function = "dbgp",
+ .speed = USB_SPEED_HIGH,
+ .bind = dbgp_bind,
+ .unbind = dbgp_unbind,
+ .setup = dbgp_setup,
+ .disconnect = dbgp_disconnect,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "dbgp"
+ },
+};
+
+static int __init dbgp_init(void)
+{
+ return usb_gadget_register_driver(&dbgp_driver);
+}
+
+static void __exit dbgp_exit(void)
+{
+ usb_gadget_unregister_driver(&dbgp_driver);
+#ifdef CONFIG_USB_G_DBGP_SERIAL
+ gserial_cleanup();
+#endif
+}
+
+MODULE_AUTHOR("Stephane Duverger");
+MODULE_LICENSE("GPL");
+module_init(dbgp_init);
+module_exit(dbgp_exit);