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>
This commit is contained in:
stephane duverger 2010-07-12 18:37:53 +02:00 committed by Greg Kroah-Hartman
parent fd63b10ba3
commit f6c826a900
3 changed files with 464 additions and 0 deletions

View File

@ -915,6 +915,34 @@ config USB_G_HID
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

View File

@ -44,6 +44,7 @@ g_printer-objs := printer.o
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-$(CONFIG_USB_G_PRINTER) += g_printer.o
obj-$(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

434
drivers/usb/gadget/dbgp.c Normal file
View File

@ -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);