LXR linux/drivers/usb/host/ehci-sysfs.c

   1/*
   2 * Copyright (C) 2007 by Alan Stern
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms of the GNU General Public License as published by the
   6 * Free Software Foundation; either version 2 of the License, or (at your
   7 * option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful, but
  10 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 * for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software Foundation,
  16 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17 */
  18
  19/* this file is part of ehci-hcd.c */
  20
  21
  22/* Display the ports dedicated to the companion controller */
  23static ssize_t show_companion(struct device *dev,
  24                              struct device_attribute *attr,
  25                              char *buf)
  26{
  27        struct ehci_hcd         *ehci;
  28        int                     nports, index, n;
  29        int                     count = PAGE_SIZE;
  30        char                    *ptr = buf;
  31
  32        ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
  33        nports = HCS_N_PORTS(ehci->hcs_params);
  34
  35        for (index = 0; index < nports; ++index) {
  36                if (test_bit(index, &ehci->companion_ports)) {
  37                        n = scnprintf(ptr, count, "%d\n", index + 1);
  38                        ptr += n;
  39                        count -= n;
  40                }
  41        }
  42        return ptr - buf;
  43}
  44
  45/*
  46 * Dedicate or undedicate a port to the companion controller.
  47 * Syntax is "[-]portnum", where a leading '-' sign means
  48 * return control of the port to the EHCI controller.
  49 */
  50static ssize_t store_companion(struct device *dev,
  51                               struct device_attribute *attr,
  52                               const char *buf, size_t count)
  53{
  54        struct ehci_hcd         *ehci;
  55        int                     portnum, new_owner;
  56
  57        ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
  58        new_owner = PORT_OWNER;         /* Owned by companion */
  59        if (sscanf(buf, "%d", &portnum) != 1)
  60                return -EINVAL;
  61        if (portnum < 0) {
  62                portnum = - portnum;
  63                new_owner = 0;          /* Owned by EHCI */
  64        }
  65        if (portnum <= 0 || portnum > HCS_N_PORTS(ehci->hcs_params))
  66                return -ENOENT;
  67        portnum--;
  68        if (new_owner)
  69                set_bit(portnum, &ehci->companion_ports);
  70        else
  71                clear_bit(portnum, &ehci->companion_ports);
  72        set_owner(ehci, portnum, new_owner);
  73        return count;
  74}
  75static DEVICE_ATTR(companion, 0644, show_companion, store_companion);
  76
  77
  78/*
  79 * Display / Set uframe_periodic_max
  80 */
  81static ssize_t show_uframe_periodic_max(struct device *dev,
  82                                        struct device_attribute *attr,
  83                                        char *buf)
  84{
  85        struct ehci_hcd         *ehci;
  86        int                     n;
  87
  88        ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
  89        n = scnprintf(buf, PAGE_SIZE, "%d\n", ehci->uframe_periodic_max);
  90        return n;
  91}
  92
  93
  94static ssize_t store_uframe_periodic_max(struct device *dev,
  95                                        struct device_attribute *attr,
  96                                        const char *buf, size_t count)
  97{
  98        struct ehci_hcd         *ehci;
  99        unsigned                uframe_periodic_max;
 100        unsigned                frame, uframe;
 101        unsigned short          allocated_max;
 102        unsigned long           flags;
 103        ssize_t                 ret;
 104
 105        ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
 106        if (kstrtouint(buf, 0, &uframe_periodic_max) < 0)
 107                return -EINVAL;
 108
 109        if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) {
 110                ehci_info(ehci, "rejecting invalid request for "
 111                                "uframe_periodic_max=%u\n", uframe_periodic_max);
 112                return -EINVAL;
 113        }
 114
 115        ret = -EINVAL;
 116
 117        /*
 118         * lock, so that our checking does not race with possible periodic
 119         * bandwidth allocation through submitting new urbs.
 120         */
 121        spin_lock_irqsave (&ehci->lock, flags);
 122
 123        /*
 124         * for request to decrease max periodic bandwidth, we have to check
 125         * every microframe in the schedule to see whether the decrease is
 126         * possible.
 127         */
 128        if (uframe_periodic_max < ehci->uframe_periodic_max) {
 129                allocated_max = 0;
 130
 131                for (frame = 0; frame < ehci->periodic_size; ++frame)
 132                        for (uframe = 0; uframe < 7; ++uframe)
 133                                allocated_max = max(allocated_max,
 134                                                    periodic_usecs (ehci, frame, uframe));
 135
 136                if (allocated_max > uframe_periodic_max) {
 137                        ehci_info(ehci,
 138                                "cannot decrease uframe_periodic_max becase "
 139                                "periodic bandwidth is already allocated "
 140                                "(%u > %u)\n",
 141                                allocated_max, uframe_periodic_max);
 142                        goto out_unlock;
 143                }
 144        }
 145
 146        /* increasing is always ok */
 147
 148        ehci_info(ehci, "setting max periodic bandwidth to %u%% "
 149                        "(== %u usec/uframe)\n",
 150                        100*uframe_periodic_max/125, uframe_periodic_max);
 151
 152        if (uframe_periodic_max != 100)
 153                ehci_warn(ehci, "max periodic bandwidth set is non-standard\n");
 154
 155        ehci->uframe_periodic_max = uframe_periodic_max;
 156        ret = count;
 157
 158out_unlock:
 159        spin_unlock_irqrestore (&ehci->lock, flags);
 160        return ret;
 161}
 162static DEVICE_ATTR(uframe_periodic_max, 0644, show_uframe_periodic_max, store_uframe_periodic_max);
 163
 164
 165static inline int create_sysfs_files(struct ehci_hcd *ehci)
 166{
 167        struct device   *controller = ehci_to_hcd(ehci)->self.controller;
 168        int     i = 0;
 169
 170        /* with integrated TT there is no companion! */
 171        if (!ehci_is_TDI(ehci))
 172                i = device_create_file(controller, &dev_attr_companion);
 173        if (i)
 174                goto out;
 175
 176        i = device_create_file(controller, &dev_attr_uframe_periodic_max);
 177out:
 178        return i;
 179}
 180
 181static inline void remove_sysfs_files(struct ehci_hcd *ehci)
 182{
 183        struct device   *controller = ehci_to_hcd(ehci)->self.controller;
 184
 185        /* with integrated TT there is no companion! */
 186        if (!ehci_is_TDI(ehci))
 187                device_remove_file(controller, &dev_attr_companion);
 188
 189        device_remove_file(controller, &dev_attr_uframe_periodic_max);
 190}
 191