option_ms.c
// SPDX-License-Identifier: GPL-2.0+
/*
* Driver for Option High Speed Mobile Devices.
*
* (c) 2008 Dan Williams <dcbw@redhat.com>
*
* Inspiration taken from sierra_ms.c by Kevin Lloyd <klloyd@sierrawireless.com>
*/
#include <linux/usb.h>
#include <linux/slab.h>
#include <linux/module.h>
#include "usb.h"
#include "transport.h"
#include "option_ms.h"
#include "debug.h"
#define ZCD_FORCE_MODEM 0x01
#define ZCD_ALLOW_MS 0x02
static unsigned int option_zero_cd = ZCD_FORCE_MODEM;
module_param(option_zero_cd, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(option_zero_cd, "ZeroCD mode (1=Force Modem (default),"
" 2=Allow CD-Rom");
#define RESPONSE_LEN 1024
static int option_rezero(struct us_data *us)
{
static const unsigned char rezero_msg[] = {
0x55, 0x53, 0x42, 0x43, 0x78, 0x56, 0x34, 0x12,
0x01, 0x00, 0x00, 0x00, 0x80, 0x00, 0x06, 0x01,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
char *buffer;
int result;
usb_stor_dbg(us, "Option MS: %s\n", "DEVICE MODE SWITCH");
buffer = kzalloc(RESPONSE_LEN, GFP_KERNEL);
if (buffer == NULL)
return USB_STOR_TRANSPORT_ERROR;
memcpy(buffer, rezero_msg, sizeof(rezero_msg));
result = usb_stor_bulk_transfer_buf(us,
us->send_bulk_pipe,
buffer, sizeof(rezero_msg), NULL);
if (result != USB_STOR_XFER_GOOD) {
result = USB_STOR_XFER_ERROR;
goto out;
}
/*
* Some of the devices need to be asked for a response, but we don't
* care what that response is.
*/
usb_stor_bulk_transfer_buf(us,
us->recv_bulk_pipe,
buffer, RESPONSE_LEN, NULL);
/* Read the CSW */
usb_stor_bulk_transfer_buf(us,
us->recv_bulk_pipe,
buffer, 13, NULL);
result = USB_STOR_XFER_GOOD;
out:
kfree(buffer);
return result;
}
static int option_inquiry(struct us_data *us)
{
static const unsigned char inquiry_msg[] = {
0x55, 0x53, 0x42, 0x43, 0x12, 0x34, 0x56, 0x78,
0x24, 0x00, 0x00, 0x00, 0x80, 0x00, 0x06, 0x12,
0x00, 0x00, 0x00, 0x24, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
char *buffer;
int result;
usb_stor_dbg(us, "Option MS: %s\n", "device inquiry for vendor name");
buffer = kzalloc(0x24, GFP_KERNEL);
if (buffer == NULL)
return USB_STOR_TRANSPORT_ERROR;
memcpy(buffer, inquiry_msg, sizeof(inquiry_msg));
result = usb_stor_bulk_transfer_buf(us,
us->send_bulk_pipe,
buffer, sizeof(inquiry_msg), NULL);
if (result != USB_STOR_XFER_GOOD) {
result = USB_STOR_XFER_ERROR;
goto out;
}
result = usb_stor_bulk_transfer_buf(us,
us->recv_bulk_pipe,
buffer, 0x24, NULL);
if (result != USB_STOR_XFER_GOOD) {
result = USB_STOR_XFER_ERROR;
goto out;
}
result = memcmp(buffer+8, "Option", 6);
if (result != 0)
result = memcmp(buffer+8, "ZCOPTION", 8);
/* Read the CSW */
usb_stor_bulk_transfer_buf(us,
us->recv_bulk_pipe,
buffer, 13, NULL);
out:
kfree(buffer);
return result;
}
int option_ms_init(struct us_data *us)
{
int result;
usb_stor_dbg(us, "Option MS: %s\n", "option_ms_init called");
/*
* Additional test for vendor information via INQUIRY,
* because some vendor/product IDs are ambiguous
*/
result = option_inquiry(us);
if (result != 0) {
usb_stor_dbg(us, "Option MS: %s\n",
"vendor is not Option or not determinable, no action taken");
return 0;
} else
usb_stor_dbg(us, "Option MS: %s\n",
"this is a genuine Option device, proceeding");
/* Force Modem mode */
if (option_zero_cd == ZCD_FORCE_MODEM) {
usb_stor_dbg(us, "Option MS: %s\n", "Forcing Modem Mode");
result = option_rezero(us);
if (result != USB_STOR_XFER_GOOD)
usb_stor_dbg(us, "Option MS: %s\n",
"Failed to switch to modem mode");
return -EIO;
} else if (option_zero_cd == ZCD_ALLOW_MS) {
/* Allow Mass Storage mode (keep CD-Rom) */
usb_stor_dbg(us, "Option MS: %s\n",
"Allowing Mass Storage Mode if device requests it");
}
return 0;
}