ehci-sysfs.c

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/*
 * Copyright (C) 2007 by Alan Stern
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* this file is part of ehci-hcd.c */


/* Display the ports dedicated to the companion controller */
static ssize_t show_companion(struct device *dev,
                  struct device_attribute *attr,
                  char *buf)
{
    struct ehci_hcd     *ehci;
    int         nports, index, n;
    int         count = PAGE_SIZE;
    char            *ptr = buf;

    ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
    nports = HCS_N_PORTS(ehci->hcs_params);

    for (index = 0; index < nports; ++index) {
        if (test_bit(index, &ehci->companion_ports)) {
            n = scnprintf(ptr, count, "%d\n", index + 1);
            ptr += n;
            count -= n;
        }
    }
    return ptr - buf;
}

/*
 * Dedicate or undedicate a port to the companion controller.
 * Syntax is "[-]portnum", where a leading '-' sign means
 * return control of the port to the EHCI controller.
 */
static ssize_t store_companion(struct device *dev,
                   struct device_attribute *attr,
                   const char *buf, size_t count)
{
    struct ehci_hcd     *ehci;
    int         portnum, new_owner;

    ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
    new_owner = PORT_OWNER;     /* Owned by companion */
    if (sscanf(buf, "%d", &portnum) != 1)
        return -EINVAL;
    if (portnum < 0) {
        portnum = - portnum;
        new_owner = 0;      /* Owned by EHCI */
    }
    if (portnum <= 0 || portnum > HCS_N_PORTS(ehci->hcs_params))
        return -ENOENT;
    portnum--;
    if (new_owner)
        set_bit(portnum, &ehci->companion_ports);
    else
        clear_bit(portnum, &ehci->companion_ports);
    set_owner(ehci, portnum, new_owner);
    return count;
}
static DEVICE_ATTR(companion, 0644, show_companion, store_companion);


/*
 * Display / Set uframe_periodic_max
 */
static ssize_t show_uframe_periodic_max(struct device *dev,
                    struct device_attribute *attr,
                    char *buf)
{
    struct ehci_hcd     *ehci;
    int         n;

    ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
    n = scnprintf(buf, PAGE_SIZE, "%d\n", ehci->uframe_periodic_max);
    return n;
}


static ssize_t store_uframe_periodic_max(struct device *dev,
                    struct device_attribute *attr,
                    const char *buf, size_t count)
{
    struct ehci_hcd     *ehci;
    unsigned        uframe_periodic_max;
    unsigned        frame, uframe;
    unsigned short      allocated_max;
    unsigned long       flags;
    ssize_t         ret;

    ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
    if (kstrtouint(buf, 0, &uframe_periodic_max) < 0)
        return -EINVAL;

    if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) {
        ehci_info(ehci, "rejecting invalid request for "
                "uframe_periodic_max=%u\n", uframe_periodic_max);
        return -EINVAL;
    }

    ret = -EINVAL;

    /*
     * lock, so that our checking does not race with possible periodic
     * bandwidth allocation through submitting new urbs.
     */
    spin_lock_irqsave (&ehci->lock, flags);

    /*
     * for request to decrease max periodic bandwidth, we have to check
     * every microframe in the schedule to see whether the decrease is
     * possible.
     */
    if (uframe_periodic_max < ehci->uframe_periodic_max) {
        allocated_max = 0;

        for (frame = 0; frame < ehci->periodic_size; ++frame)
            for (uframe = 0; uframe < 7; ++uframe)
                allocated_max = max(allocated_max,
                            periodic_usecs (ehci, frame, uframe));

        if (allocated_max > uframe_periodic_max) {
            ehci_info(ehci,
                "cannot decrease uframe_periodic_max becase "
                "periodic bandwidth is already allocated "
                "(%u > %u)\n",
                allocated_max, uframe_periodic_max);
            goto out_unlock;
        }
    }

    /* increasing is always ok */

    ehci_info(ehci, "setting max periodic bandwidth to %u%% "
            "(== %u usec/uframe)\n",
            100*uframe_periodic_max/125, uframe_periodic_max);

    if (uframe_periodic_max != 100)
        ehci_warn(ehci, "max periodic bandwidth set is non-standard\n");

    ehci->uframe_periodic_max = uframe_periodic_max;
    ret = count;

out_unlock:
    spin_unlock_irqrestore (&ehci->lock, flags);
    return ret;
}
static DEVICE_ATTR(uframe_periodic_max, 0644, show_uframe_periodic_max, store_uframe_periodic_max);


static inline int create_sysfs_files(struct ehci_hcd *ehci)
{
    struct device   *controller = ehci_to_hcd(ehci)->self.controller;
    int i = 0;

    /* with integrated TT there is no companion! */
    if (!ehci_is_TDI(ehci))
        i = device_create_file(controller, &dev_attr_companion);
    if (i)
        goto out;

    i = device_create_file(controller, &dev_attr_uframe_periodic_max);
out:
    return i;
}

static inline void remove_sysfs_files(struct ehci_hcd *ehci)
{
    struct device   *controller = ehci_to_hcd(ehci)->self.controller;

    /* with integrated TT there is no companion! */
    if (!ehci_is_TDI(ehci))
        device_remove_file(controller, &dev_attr_companion);

    device_remove_file(controller, &dev_attr_uframe_periodic_max);
}