dbgp.c
/*
* 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/module.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;
ep->desc = desc;
err = usb_ep_enable(ep);
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;
dbg_desc.bDebugOutEndpoint = o_desc.bEndpointAddress;
#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 = -EOPNOTSUPP;
void *data = NULL;
u16 len = 0;
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;
device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
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;
}
err = 0;
} else if (request == USB_REQ_SET_FEATURE &&
value == USB_DEVICE_DEBUG_MODE) {
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;
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",
.max_speed = USB_SPEED_HIGH,
.unbind = dbgp_unbind,
.setup = dbgp_setup,
.disconnect = dbgp_disconnect,
.driver = {
.owner = THIS_MODULE,
.name = "dbgp"
},
};
static int __init dbgp_init(void)
{
return usb_gadget_probe_driver(&dbgp_driver, dbgp_bind);
}
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);