root/drivers/usb/storage/initializers.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Special Initializers for certain USB Mass Storage devices
 *
 * Current development and maintenance by:
 *   (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
 *
 * This driver is based on the 'USB Mass Storage Class' document. This
 * describes in detail the protocol used to communicate with such
 * devices.  Clearly, the designers had SCSI and ATAPI commands in
 * mind when they created this document.  The commands are all very
 * similar to commands in the SCSI-II and ATAPI specifications.
 *
 * It is important to note that in a number of cases this class
 * exhibits class-specific exemptions from the USB specification.
 * Notably the usage of NAK, STALL and ACK differs from the norm, in
 * that they are used to communicate wait, failed and OK on commands.
 *
 * Also, for certain devices, the interrupt endpoint is used to convey
 * status of a command.
 */

#include <linux/errno.h>

#include "usb.h"
#include "initializers.h"
#include "debug.h"
#include "transport.h"

/*
 * This places the Shuttle/SCM USB<->SCSI bridge devices in multi-target
 * mode
 */
int usb_stor_euscsi_init(struct us_data *us)
{
        int result;

        usb_stor_dbg(us, "Attempting to init eUSCSI bridge...\n");
        result = usb_stor_control_msg(us, us->send_ctrl_pipe,
                        0x0C, USB_RECIP_INTERFACE | USB_TYPE_VENDOR,
                        0x01, 0x0, NULL, 0x0, 5 * HZ);
        usb_stor_dbg(us, "-- result is %d\n", result);

        return 0;
}

/*
 * This function is required to activate all four slots on the UCR-61S2B
 * flash reader
 */
int usb_stor_ucr61s2b_init(struct us_data *us)
{
        struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap*) us->iobuf;
        struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap*) us->iobuf;
        int res;
        unsigned int partial;
        static const char init_string[] = "\xec\x0a\x06\x00$PCCHIPS";

        usb_stor_dbg(us, "Sending UCR-61S2B initialization packet...\n");

        bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
        bcb->Tag = 0;
        bcb->DataTransferLength = cpu_to_le32(0);
        bcb->Flags = bcb->Lun = 0;
        bcb->Length = sizeof(init_string) - 1;
        memset(bcb->CDB, 0, sizeof(bcb->CDB));
        memcpy(bcb->CDB, init_string, sizeof(init_string) - 1);

        res = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe, bcb,
                        US_BULK_CB_WRAP_LEN, &partial);
        if (res)
                return -EIO;

        usb_stor_dbg(us, "Getting status packet...\n");
        res = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe, bcs,
                        US_BULK_CS_WRAP_LEN, &partial);
        if (res)
                return -EIO;

        return 0;
}

/* This places the HUAWEI E220 devices in multi-port mode */
int usb_stor_huawei_e220_init(struct us_data *us)
{
        int result;

        result = usb_stor_control_msg(us, us->send_ctrl_pipe,
                                      USB_REQ_SET_FEATURE,
                                      USB_TYPE_STANDARD | USB_RECIP_DEVICE,
                                      0x01, 0x0, NULL, 0x0, 1 * HZ);
        usb_stor_dbg(us, "Huawei mode set result is %d\n", result);
        return 0;
}