rts51x_transport.c

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/* Driver for Realtek RTS51xx USB card reader
 *
 * Copyright(c) 2009 Realtek Semiconductor Corp. All rights reserved.
 *
 * 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, 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, see <http://www.gnu.org/licenses/>.
 *
 * Author:
 *   wwang ([email protected])
 *   No. 450, Shenhu Road, Suzhou Industry Park, Suzhou, China
 * Maintainer:
 *   Edwin Rong ([email protected])
 *   No. 450, Shenhu Road, Suzhou Industry Park, Suzhou, China
 */

#include <linux/blkdev.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/slab.h>

#include <scsi/scsi.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_device.h>

#include "debug.h"
#include "rts51x.h"
#include "rts51x_chip.h"
#include "rts51x_card.h"
#include "rts51x_scsi.h"
#include "rts51x_transport.h"
#include "trace.h"

/***********************************************************************
 * Scatter-gather transfer buffer access routines
 ***********************************************************************/

/* Copy a buffer of length buflen to/from the srb's transfer buffer.
 * Update the **sgptr and *offset variables so that the next copy will
 * pick up from where this one left off.
 */

unsigned int rts51x_access_sglist(unsigned char *buffer,
                  unsigned int buflen, void *sglist,
                  void **sgptr, unsigned int *offset,
                  enum xfer_buf_dir dir)
{
    unsigned int cnt;
    struct scatterlist *sg = (struct scatterlist *)*sgptr;

    /* We have to go through the list one entry
     * at a time.  Each s-g entry contains some number of pages, and
     * each page has to be kmap()'ed separately.  If the page is already
     * in kernel-addressable memory then kmap() will return its address.
     * If the page is not directly accessible -- such as a user buffer
     * located in high memory -- then kmap() will map it to a temporary
     * position in the kernel's virtual address space.
     */

    if (!sg)
        sg = (struct scatterlist *)sglist;

    /* This loop handles a single s-g list entry, which may
     * include multiple pages.  Find the initial page structure
     * and the starting offset within the page, and update
     * the *offset and **sgptr values for the next loop.
     */
    cnt = 0;
    while (cnt < buflen && sg) {
        struct page *page = sg_page(sg) +
            ((sg->offset + *offset) >> PAGE_SHIFT);
        unsigned int poff = (sg->offset + *offset) & (PAGE_SIZE - 1);
        unsigned int sglen = sg->length - *offset;

        if (sglen > buflen - cnt) {

            /* Transfer ends within this s-g entry */
            sglen = buflen - cnt;
            *offset += sglen;
        } else {

            /* Transfer continues to next s-g entry */
            *offset = 0;
            sg = sg_next(sg);
        }

        /* Transfer the data for all the pages in this
         * s-g entry.  For each page: call kmap(), do the
         * transfer, and call kunmap() immediately after. */
        while (sglen > 0) {
            unsigned int plen = min(sglen, (unsigned int)
                        PAGE_SIZE - poff);
            unsigned char *ptr = kmap(page);

            if (dir == TO_XFER_BUF)
                memcpy(ptr + poff, buffer + cnt, plen);
            else
                memcpy(buffer + cnt, ptr + poff, plen);
            kunmap(page);

            /* Start at the beginning of the next page */
            poff = 0;
            ++page;
            cnt += plen;
            sglen -= plen;
        }
    }
    *sgptr = sg;

    /* Return the amount actually transferred */
    return cnt;
}

static unsigned int rts51x_access_xfer_buf(unsigned char *buffer,
                    unsigned int buflen, struct scsi_cmnd *srb,
                    struct scatterlist **sgptr,
                    unsigned int *offset, enum xfer_buf_dir dir)
{
    return rts51x_access_sglist(buffer, buflen, (void *)scsi_sglist(srb),
                    (void **)sgptr, offset, dir);
}

/* Store the contents of buffer into srb's transfer buffer and set the
 * SCSI residue.
 */
void rts51x_set_xfer_buf(unsigned char *buffer,
             unsigned int buflen, struct scsi_cmnd *srb)
{
    unsigned int offset = 0;
    struct scatterlist *sg = NULL;

    buflen = min(buflen, scsi_bufflen(srb));
    buflen = rts51x_access_xfer_buf(buffer, buflen, srb, &sg, &offset,
                    TO_XFER_BUF);
    if (buflen < scsi_bufflen(srb))
        scsi_set_resid(srb, scsi_bufflen(srb) - buflen);
}

void rts51x_get_xfer_buf(unsigned char *buffer,
             unsigned int buflen, struct scsi_cmnd *srb)
{
    unsigned int offset = 0;
    struct scatterlist *sg = NULL;

    buflen = min(buflen, scsi_bufflen(srb));
    buflen = rts51x_access_xfer_buf(buffer, buflen, srb, &sg, &offset,
                    FROM_XFER_BUF);
    if (buflen < scsi_bufflen(srb))
        scsi_set_resid(srb, scsi_bufflen(srb) - buflen);
}

/* This is the completion handler which will wake us up when an URB
 * completes.
 */
static void urb_done_completion(struct urb *urb)
{
    struct completion *urb_done_ptr = urb->context;

    if (urb_done_ptr)
        complete(urb_done_ptr);
}

/* This is the common part of the URB message submission code
 *
 * All URBs from the driver involved in handling a queued scsi
 * command _must_ pass through this function (or something like it) for the
 * abort mechanisms to work properly.
 */
static int rts51x_msg_common(struct rts51x_chip *chip, struct urb *urb,
                 int timeout)
{
    struct rts51x_usb *rts51x = chip->usb;
    struct completion urb_done;
    long timeleft;
    int status;

    /* don't submit URBs during abort processing */
    if (test_bit(FLIDX_ABORTING, &rts51x->dflags))
        TRACE_RET(chip, -EIO);

    /* set up data structures for the wakeup system */
    init_completion(&urb_done);

    /* fill the common fields in the URB */
    urb->context = &urb_done;
    urb->actual_length = 0;
    urb->error_count = 0;
    urb->status = 0;

    /* we assume that if transfer_buffer isn't us->iobuf then it
     * hasn't been mapped for DMA.  Yes, this is clunky, but it's
     * easier than always having the caller tell us whether the
     * transfer buffer has already been mapped. */
    urb->transfer_flags = URB_NO_SETUP_DMA_MAP;
    if (urb->transfer_buffer == rts51x->iobuf) {
        urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
        urb->transfer_dma = rts51x->iobuf_dma;
    }
    urb->setup_dma = rts51x->cr_dma;

    /* submit the URB */
    status = usb_submit_urb(urb, GFP_NOIO);
    if (status) {
        /* something went wrong */
        TRACE_RET(chip, status);
    }

    /* since the URB has been submitted successfully, it's now okay
     * to cancel it */
    set_bit(FLIDX_URB_ACTIVE, &rts51x->dflags);

    /* did an abort occur during the submission? */
    if (test_bit(FLIDX_ABORTING, &rts51x->dflags)) {

        /* cancel the URB, if it hasn't been cancelled already */
        if (test_and_clear_bit(FLIDX_URB_ACTIVE, &rts51x->dflags)) {
            RTS51X_DEBUGP("-- cancelling URB\n");
            usb_unlink_urb(urb);
        }
    }

    /* wait for the completion of the URB */
    timeleft =
        wait_for_completion_interruptible_timeout(&urb_done,
                              (timeout * HZ /
                               1000) ? :
                              MAX_SCHEDULE_TIMEOUT);

    clear_bit(FLIDX_URB_ACTIVE, &rts51x->dflags);

    if (timeleft <= 0) {
        RTS51X_DEBUGP("%s -- cancelling URB\n",
                   timeleft == 0 ? "Timeout" : "Signal");
        usb_kill_urb(urb);
        if (timeleft == 0)
            status = -ETIMEDOUT;
        else
            status = -EINTR;
    } else {
        status = urb->status;
    }

    return status;
}

static int rts51x_clear_halt(struct rts51x_chip *chip, unsigned int pipe);

/*
 * Interpret the results of a URB transfer
 */
static int interpret_urb_result(struct rts51x_chip *chip, unsigned int pipe,
                unsigned int length, int result,
                unsigned int partial)
{
    int retval = STATUS_SUCCESS;

    /* RTS51X_DEBUGP("Status code %d; transferred %u/%u\n",
                result, partial, length); */
    switch (result) {
        /* no error code; did we send all the data? */
    case 0:
        if (partial != length) {
            RTS51X_DEBUGP("-- short transfer\n");
            TRACE_RET(chip, STATUS_TRANS_SHORT);
        }
        /* RTS51X_DEBUGP("-- transfer complete\n"); */
        return STATUS_SUCCESS;
        /* stalled */
    case -EPIPE:
        /* for control endpoints, (used by CB[I]) a stall indicates
         * a failed command */
        if (usb_pipecontrol(pipe)) {
            RTS51X_DEBUGP("-- stall on control pipe\n");
            TRACE_RET(chip, STATUS_STALLED);
        }
        /* for other sorts of endpoint, clear the stall */
        RTS51X_DEBUGP("clearing endpoint halt for pipe 0x%x\n", pipe);
        if (rts51x_clear_halt(chip, pipe) < 0)
            TRACE_RET(chip, STATUS_ERROR);
        retval = STATUS_STALLED;
        TRACE_GOTO(chip, Exit);

        /* babble - the device tried to send more than
         * we wanted to read */
    case -EOVERFLOW:
        RTS51X_DEBUGP("-- babble\n");
        retval = STATUS_TRANS_LONG;
        TRACE_GOTO(chip, Exit);

        /* the transfer was cancelled by abort,
         * disconnect, or timeout */
    case -ECONNRESET:
        RTS51X_DEBUGP("-- transfer cancelled\n");
        retval = STATUS_ERROR;
        TRACE_GOTO(chip, Exit);

        /* short scatter-gather read transfer */
    case -EREMOTEIO:
        RTS51X_DEBUGP("-- short read transfer\n");
        retval = STATUS_TRANS_SHORT;
        TRACE_GOTO(chip, Exit);

        /* abort or disconnect in progress */
    case -EIO:
        RTS51X_DEBUGP("-- abort or disconnect in progress\n");
        retval = STATUS_ERROR;
        TRACE_GOTO(chip, Exit);

    case -ETIMEDOUT:
        RTS51X_DEBUGP("-- time out\n");
        retval = STATUS_TIMEDOUT;
        TRACE_GOTO(chip, Exit);

        /* the catch-all error case */
    default:
        RTS51X_DEBUGP("-- unknown error\n");
        retval = STATUS_ERROR;
        TRACE_GOTO(chip, Exit);
    }

Exit:
    if ((retval != STATUS_SUCCESS) && !usb_pipecontrol(pipe))
        rts51x_clear_hw_error(chip);

    return retval;
}

int rts51x_ctrl_transfer(struct rts51x_chip *chip, unsigned int pipe,
             u8 request, u8 requesttype, u16 value, u16 index,
             void *data, u16 size, int timeout)
{
    struct rts51x_usb *rts51x = chip->usb;
    int result;

    RTS51X_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
               __func__, request, requesttype, value, index, size);

    /* fill in the devrequest structure */
    rts51x->cr->bRequestType = requesttype;
    rts51x->cr->bRequest = request;
    rts51x->cr->wValue = cpu_to_le16(value);
    rts51x->cr->wIndex = cpu_to_le16(index);
    rts51x->cr->wLength = cpu_to_le16(size);

    /* fill and submit the URB */
    usb_fill_control_urb(rts51x->current_urb, rts51x->pusb_dev, pipe,
                 (unsigned char *)rts51x->cr, data, size,
                 urb_done_completion, NULL);
    result = rts51x_msg_common(chip, rts51x->current_urb, timeout);

    return interpret_urb_result(chip, pipe, size, result,
                    rts51x->current_urb->actual_length);
}

static int rts51x_clear_halt(struct rts51x_chip *chip, unsigned int pipe)
{
    int result;
    int endp = usb_pipeendpoint(pipe);

    if (usb_pipein(pipe))
        endp |= USB_DIR_IN;

    result = rts51x_ctrl_transfer(chip, SND_CTRL_PIPE(chip),
                      USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
                      USB_ENDPOINT_HALT, endp, NULL, 0, 3000);
    if (result != STATUS_SUCCESS)
        TRACE_RET(chip, STATUS_FAIL);

    usb_reset_endpoint(chip->usb->pusb_dev, endp);

    return STATUS_SUCCESS;
}

static void rts51x_sg_clean(struct usb_sg_request *io)
{
    if (io->urbs) {
        while (io->entries--)
            usb_free_urb(io->urbs[io->entries]);
        kfree(io->urbs);
        io->urbs = NULL;
    }
    io->dev = NULL;
}

static int rts51x_sg_init(struct usb_sg_request *io, struct usb_device *dev,
           unsigned pipe, unsigned period, struct scatterlist *sg,
           int nents, size_t length, gfp_t mem_flags)
{
    return usb_sg_init(io, dev, pipe, period, sg, nents, length, mem_flags);
}

static int rts51x_sg_wait(struct usb_sg_request *io, int timeout)
{
    long timeleft;
    int i;
    int entries = io->entries;

    /* queue the urbs.  */
    spin_lock_irq(&io->lock);
    i = 0;
    while (i < entries && !io->status) {
        int retval;

        io->urbs[i]->dev = io->dev;
        retval = usb_submit_urb(io->urbs[i], GFP_ATOMIC);

        /* after we submit, let completions or cancelations fire;
         * we handshake using io->status.
         */
        spin_unlock_irq(&io->lock);
        switch (retval) {
            /* maybe the retry will recover */
        case -ENXIO:    /* hc didn't queue this one */
        case -EAGAIN:
        case -ENOMEM:
            io->urbs[i]->dev = NULL;
            retval = 0;
            yield();
            break;

            /* no error? continue immediately.
             *
             * NOTE: to work better with UHCI (4K I/O buffer may
             * need 3K of TDs) it may be good to limit how many
             * URBs are queued at once; N milliseconds?
             */
        case 0:
            ++i;
            cpu_relax();
            break;

            /* fail any uncompleted urbs */
        default:
            io->urbs[i]->dev = NULL;
            io->urbs[i]->status = retval;
            dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
                __func__, retval);
            usb_sg_cancel(io);
        }
        spin_lock_irq(&io->lock);
        if (retval && (io->status == 0 || io->status == -ECONNRESET))
            io->status = retval;
    }
    io->count -= entries - i;
    if (io->count == 0)
        complete(&io->complete);
    spin_unlock_irq(&io->lock);

    timeleft =
        wait_for_completion_interruptible_timeout(&io->complete,
                              (timeout * HZ /
                               1000) ? :
                              MAX_SCHEDULE_TIMEOUT);
    if (timeleft <= 0) {
        RTS51X_DEBUGP("%s -- cancelling SG request\n",
                   timeleft == 0 ? "Timeout" : "Signal");
        usb_sg_cancel(io);
        if (timeleft == 0)
            io->status = -ETIMEDOUT;
        else
            io->status = -EINTR;
    }

    rts51x_sg_clean(io);
    return io->status;
}

/*
 * Transfer a scatter-gather list via bulk transfer
 *
 * This function does basically the same thing as usb_stor_bulk_transfer_buf()
 * above, but it uses the usbcore scatter-gather library.
 */
static int rts51x_bulk_transfer_sglist(struct rts51x_chip *chip,
                       unsigned int pipe,
                       struct scatterlist *sg, int num_sg,
                       unsigned int length,
                       unsigned int *act_len, int timeout)
{
    int result;

    /* don't submit s-g requests during abort processing */
    if (test_bit(FLIDX_ABORTING, &chip->usb->dflags))
        TRACE_RET(chip, STATUS_ERROR);

    /* initialize the scatter-gather request block */
    RTS51X_DEBUGP("%s: xfer %u bytes, %d entries\n", __func__,
               length, num_sg);
    result =
        rts51x_sg_init(&chip->usb->current_sg, chip->usb->pusb_dev, pipe, 0,
               sg, num_sg, length, GFP_NOIO);
    if (result) {
        RTS51X_DEBUGP("rts51x_sg_init returned %d\n", result);
        TRACE_RET(chip, STATUS_ERROR);
    }

    /* since the block has been initialized successfully, it's now
     * okay to cancel it */
    set_bit(FLIDX_SG_ACTIVE, &chip->usb->dflags);

    /* did an abort occur during the submission? */
    if (test_bit(FLIDX_ABORTING, &chip->usb->dflags)) {

        /* cancel the request, if it hasn't been cancelled already */
        if (test_and_clear_bit(FLIDX_SG_ACTIVE, &chip->usb->dflags)) {
            RTS51X_DEBUGP("-- cancelling sg request\n");
            usb_sg_cancel(&chip->usb->current_sg);
        }
    }

    /* wait for the completion of the transfer */
    result = rts51x_sg_wait(&chip->usb->current_sg, timeout);

    clear_bit(FLIDX_SG_ACTIVE, &chip->usb->dflags);

    /* result = us->current_sg.status; */
    if (act_len)
        *act_len = chip->usb->current_sg.bytes;
    return interpret_urb_result(chip, pipe, length, result,
                    chip->usb->current_sg.bytes);
}

static int rts51x_bulk_transfer_buf(struct rts51x_chip *chip,
                 unsigned int pipe,
                 void *buf, unsigned int length,
                 unsigned int *act_len, int timeout)
{
    int result;

    /* fill and submit the URB */
    usb_fill_bulk_urb(chip->usb->current_urb, chip->usb->pusb_dev, pipe,
              buf, length, urb_done_completion, NULL);
    result = rts51x_msg_common(chip, chip->usb->current_urb, timeout);

    /* store the actual length of the data transferred */
    if (act_len)
        *act_len = chip->usb->current_urb->actual_length;
    return interpret_urb_result(chip, pipe, length, result,
                    chip->usb->current_urb->actual_length);
}

int rts51x_transfer_data(struct rts51x_chip *chip, unsigned int pipe,
             void *buf, unsigned int len, int use_sg,
             unsigned int *act_len, int timeout)
{
    int result;

    if (timeout < 600)
        timeout = 600;

    if (use_sg) {
        result =
            rts51x_bulk_transfer_sglist(chip, pipe,
                        (struct scatterlist *)buf,
                        use_sg, len, act_len, timeout);
    } else {
        result =
            rts51x_bulk_transfer_buf(chip, pipe, buf, len, act_len,
                         timeout);
    }

    return result;
}

int rts51x_transfer_data_partial(struct rts51x_chip *chip, unsigned int pipe,
                 void *buf, void **ptr, unsigned int *offset,
                 unsigned int len, int use_sg,
                 unsigned int *act_len, int timeout)
{
    int result;

    if (timeout < 600)
        timeout = 600;

    if (use_sg) {
        void *tmp_buf = kmalloc(len, GFP_KERNEL);
        if (!tmp_buf)
            TRACE_RET(chip, STATUS_NOMEM);

        if (usb_pipeout(pipe)) {
            rts51x_access_sglist(tmp_buf, len, buf, ptr, offset,
                         FROM_XFER_BUF);
        }
        result =
            rts51x_bulk_transfer_buf(chip, pipe, tmp_buf, len, act_len,
                         timeout);
        if (result == STATUS_SUCCESS) {
            if (usb_pipein(pipe)) {
                rts51x_access_sglist(tmp_buf, len, buf, ptr,
                             offset, TO_XFER_BUF);
            }
        }

        kfree(tmp_buf);
    } else {
        unsigned int step = 0;
        if (offset)
            step = *offset;
        result =
            rts51x_bulk_transfer_buf(chip, pipe, buf + step, len,
                         act_len, timeout);
        if (act_len)
            step += *act_len;
        else
            step += len;
        if (offset)
            *offset = step;
    }

    return result;
}

int rts51x_get_epc_status(struct rts51x_chip *chip, u16 *status)
{
    unsigned int pipe = RCV_INTR_PIPE(chip);
    struct usb_host_endpoint *ep;
    struct completion urb_done;
    int result;

    if (!status)
        TRACE_RET(chip, STATUS_ERROR);

    /* set up data structures for the wakeup system */
    init_completion(&urb_done);

    ep = chip->usb->pusb_dev->ep_in[usb_pipeendpoint(pipe)];

    /* fill and submit the URB */
    /* We set interval to 1 here, so the polling interval is controlled
     * by our polling thread */
    usb_fill_int_urb(chip->usb->intr_urb, chip->usb->pusb_dev, pipe,
             status, 2, urb_done_completion, &urb_done, 1);

    result = rts51x_msg_common(chip, chip->usb->intr_urb, 50);

    return interpret_urb_result(chip, pipe, 2, result,
                    chip->usb->intr_urb->actual_length);
}

u8 media_not_present[] = {
    0x70, 0, 0x02, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0x3A, 0, 0, 0, 0, 0 };
u8 invalid_cmd_field[] = {
    0x70, 0, 0x05, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0x24, 0, 0, 0, 0, 0 };

void rts51x_invoke_transport(struct scsi_cmnd *srb, struct rts51x_chip *chip)
{
    int result;

#ifdef CONFIG_PM
    if (chip->option.ss_en) {
        if (srb->cmnd[0] == TEST_UNIT_READY) {
            if (RTS51X_CHK_STAT(chip, STAT_SS)) {
                if (check_fake_card_ready(chip,
                            SCSI_LUN(srb))) {
                    srb->result = SAM_STAT_GOOD;
                } else {
                    srb->result = SAM_STAT_CHECK_CONDITION;
                    memcpy(srb->sense_buffer,
                           media_not_present, SENSE_SIZE);
                }
                return;
            }
        } else if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {
            if (RTS51X_CHK_STAT(chip, STAT_SS)) {
                int prevent = srb->cmnd[4] & 0x1;

                if (prevent) {
                    srb->result = SAM_STAT_CHECK_CONDITION;
                    memcpy(srb->sense_buffer,
                           invalid_cmd_field, SENSE_SIZE);
                } else {
                    srb->result = SAM_STAT_GOOD;
                }
                return;
            }
        } else {
            if (RTS51X_CHK_STAT(chip, STAT_SS)
                || RTS51X_CHK_STAT(chip, STAT_SS_PRE)) {
                /* Wake up device */
                RTS51X_DEBUGP("Try to wake up device\n");
                chip->resume_from_scsi = 1;

                rts51x_try_to_exit_ss(chip);

                if (RTS51X_CHK_STAT(chip, STAT_SS)) {
                    wait_timeout(3000);

                    rts51x_init_chip(chip);
                    rts51x_init_cards(chip);
                }
            }
        }
    }
#endif

    result = rts51x_scsi_handler(srb, chip);

    /* if there is a transport error, reset and don't auto-sense */
    if (result == TRANSPORT_ERROR) {
        RTS51X_DEBUGP("-- transport indicates error, resetting\n");
        srb->result = DID_ERROR << 16;
        goto Handle_Errors;
    }

    srb->result = SAM_STAT_GOOD;

    /*
     * If we have a failure, we're going to do a REQUEST_SENSE
     * automatically.  Note that we differentiate between a command
     * "failure" and an "error" in the transport mechanism.
     */
    if (result == TRANSPORT_FAILED) {
        /* set the result so the higher layers expect this data */
        srb->result = SAM_STAT_CHECK_CONDITION;
        memcpy(srb->sense_buffer,
               (unsigned char *)&(chip->sense_buffer[SCSI_LUN(srb)]),
               sizeof(struct sense_data_t));
    }

    return;

    /* Error and abort processing: try to resynchronize with the device
     * by issuing a port reset.  If that fails, try a class-specific
     * device reset. */
Handle_Errors:
    return;
}