mspdebug/transport/cdc_acm.c

325 lines
7.3 KiB
C

/* MSPDebug - debugging tool for the eZ430
* Copyright (C) 2009-2012 Daniel Beer
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <usb.h>
#include "cdc_acm.h"
#include "util.h"
#include "usbutil.h"
#include "output.h"
#define READ_BUFFER_SIZE 1024
struct cdc_acm_transport {
struct transport base;
int int_number;
struct usb_dev_handle *handle;
int in_ep;
int out_ep;
/* We have to implement an intermediate read buffer, because
* some interfaces are buggy and don't like single-byte reads.
*/
int rbuf_len;
int rbuf_ptr;
char rbuf[READ_BUFFER_SIZE];
};
#define CDC_INTERFACE_CLASS 10
#define TIMEOUT 30000
/* CDC requests */
#define CDC_REQTYPE_HOST_TO_DEVICE 0x21
#define CDC_SET_CONTROL 0x22
#define CDC_SET_LINE_CODING 0x20
/* Modem control line bitmask */
#define CDC_CTRL_DTR 0x01
#define CDC_CTRL_RTS 0x02
static int usbtr_send(transport_t tr_base, const uint8_t *data, int len)
{
struct cdc_acm_transport *tr = (struct cdc_acm_transport *)tr_base;
int sent;
#ifdef DEBUG_CDC_ACM
debug_hexdump(__FILE__ ": USB transfer out", data, len);
#endif
while (len) {
sent = usb_bulk_write(tr->handle, tr->out_ep,
(char *)data, len, TIMEOUT);
if (sent <= 0) {
pr_error(__FILE__": can't send data");
return -1;
}
data += sent;
len -= sent;
}
return 0;
}
static int usbtr_recv(transport_t tr_base, uint8_t *databuf, int len)
{
struct cdc_acm_transport *tr = (struct cdc_acm_transport *)tr_base;
if (tr->rbuf_ptr >= tr->rbuf_len) {
tr->rbuf_ptr = 0;
tr->rbuf_len = usb_bulk_read(tr->handle, tr->in_ep,
tr->rbuf, sizeof(tr->rbuf),
TIMEOUT);
if (tr->rbuf_len <= 0) {
pr_error(__FILE__": can't receive data");
return -1;
}
#ifdef DEBUG_CDC_ACM
debug_hexdump(__FILE__": USB transfer in",
(uint8_t *)tr->rbuf, tr->rbuf_len);
#endif
}
if (tr->rbuf_ptr + len > tr->rbuf_len)
len = tr->rbuf_len - tr->rbuf_ptr;
memcpy(databuf, tr->rbuf + tr->rbuf_ptr, len);
tr->rbuf_ptr += len;
return len;
}
static void usbtr_destroy(transport_t tr_base)
{
struct cdc_acm_transport *tr = (struct cdc_acm_transport *)tr_base;
usb_release_interface(tr->handle, tr->int_number);
usb_close(tr->handle);
free(tr);
}
static int usbtr_flush(transport_t tr_base)
{
struct cdc_acm_transport *tr = (struct cdc_acm_transport *)tr_base;
char buf[64];
/* Flush out lingering data */
while (usb_bulk_read(tr->handle, tr->in_ep,
buf, sizeof(buf),
100) > 0);
tr->rbuf_len = 0;
tr->rbuf_ptr = 0;
return 0;
}
static int usbtr_set_modem(transport_t tr_base, transport_modem_t state)
{
struct cdc_acm_transport *tr = (struct cdc_acm_transport *)tr_base;
int value = 0;
if (state & TRANSPORT_MODEM_DTR)
value |= CDC_CTRL_DTR;
if (state & TRANSPORT_MODEM_RTS)
value |= CDC_CTRL_RTS;
#ifdef DEBUG_CDC_ACM
printc(__FILE__": modem ctrl = 0x%x\n", value);
#endif
if (usb_control_msg(tr->handle, CDC_REQTYPE_HOST_TO_DEVICE,
CDC_SET_CONTROL, value, 0,
NULL, 0, 300) < 0) {
pr_error("cdc_acm: failed to set modem control lines\n");
return -1;
}
return 0;
}
static const struct transport_class cdc_acm_class = {
.destroy = usbtr_destroy,
.send = usbtr_send,
.recv = usbtr_recv,
.flush = usbtr_flush,
.set_modem = usbtr_set_modem
};
static int find_interface(struct cdc_acm_transport *tr,
struct usb_device *dev)
{
struct usb_config_descriptor *c = &dev->config[0];
int i;
for (i = 0; i < c->bNumInterfaces; i++) {
struct usb_interface *intf = &c->interface[i];
struct usb_interface_descriptor *desc = &intf->altsetting[0];
int j;
if (desc->bInterfaceClass != CDC_INTERFACE_CLASS)
continue;
/* Look for bulk in/out endpoints */
tr->in_ep = -1;
tr->out_ep = -1;
for (j = 0; j < desc->bNumEndpoints; j++) {
struct usb_endpoint_descriptor *ep =
&desc->endpoint[j];
const int type =
ep->bmAttributes & USB_ENDPOINT_TYPE_MASK;
const int addr = ep->bEndpointAddress;
if (type != USB_ENDPOINT_TYPE_BULK)
continue;
if (addr & USB_ENDPOINT_DIR_MASK)
tr->in_ep = addr;
else
tr->out_ep = addr;
}
if (tr->in_ep >= 0 && tr->out_ep >= 0) {
tr->int_number = i;
return 0;
}
}
return -1;
}
static int open_interface(struct cdc_acm_transport *tr,
struct usb_device *dev)
{
#if defined(__linux__)
int drv;
char drName[256];
#endif
tr->handle = usb_open(dev);
if (!tr->handle) {
pr_error(__FILE__": can't open device");
return -1;
}
#if defined(__linux__)
drv = usb_get_driver_np(tr->handle, tr->int_number, drName,
sizeof(drName));
if (drv >= 0) {
if (usb_detach_kernel_driver_np(tr->handle,
tr->int_number) < 0)
pr_error(__FILE__": warning: can't detach "
"kernel driver");
}
#endif
if (usb_claim_interface(tr->handle, tr->int_number) < 0) {
pr_error(__FILE__": can't claim interface");
usb_close(tr->handle);
return -1;
}
return 0;
}
static int configure_port(struct cdc_acm_transport *tr, int baud_rate)
{
uint8_t line_coding[7];
line_coding[0] = baud_rate & 0xff;
line_coding[1] = (baud_rate >> 8) & 0xff;
line_coding[2] = (baud_rate >> 16) & 0xff;
line_coding[3] = (baud_rate >> 24) & 0xff;
line_coding[4] = 0; /* 1 stop bit */
line_coding[5] = 0; /* no parity */
line_coding[6] = 8; /* 8 data bits */
if (usb_control_msg(tr->handle, CDC_REQTYPE_HOST_TO_DEVICE,
CDC_SET_LINE_CODING, 0, 0,
(char *)line_coding, 7, 300) < 0) {
pr_error("cdc_acm: failed to set line coding\n");
return -1;
}
if (usb_control_msg(tr->handle, CDC_REQTYPE_HOST_TO_DEVICE,
CDC_SET_CONTROL, 0, 0, NULL, 0, 300) < 0) {
pr_error("cdc_acm: failed to set modem control lines\n");
return -1;
}
return 0;
}
transport_t cdc_acm_open(const char *devpath, const char *requested_serial,
int baud_rate, uint16_t vendor, uint16_t product)
{
struct cdc_acm_transport *tr = malloc(sizeof(*tr));
struct usb_device *dev;
if (!tr) {
pr_error(__FILE__": can't allocate memory");
return NULL;
}
tr->base.ops = &cdc_acm_class;
usb_init();
usb_find_busses();
usb_find_devices();
if (devpath)
dev = usbutil_find_by_loc(devpath);
else
dev = usbutil_find_by_id(vendor, product, requested_serial);
if (!dev) {
free(tr);
return NULL;
}
if (find_interface(tr, dev) < 0) {
printc_err(__FILE__ ": failed to locate CDC-ACM interface\n");
free(tr);
return NULL;
}
if (open_interface(tr, dev) < 0) {
printc_err(__FILE__": failed to open interface\n");
free(tr);
return NULL;
}
if (configure_port(tr, baud_rate) < 0) {
usb_release_interface(tr->handle, tr->int_number);
usb_close(tr->handle);
free(tr);
return NULL;
}
usbtr_flush(&tr->base);
return (transport_t)tr;
}