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 */
  23 static 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  */
  50 static 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 }
  75 static DEVICE_ATTR(companion, 0644, show_companion, store_companion);
  76
  77
  78 /*
  79  * Display / Set uframe_periodic_max
  80  */
  81 static 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
  94 static 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
 158 out_unlock:
 159         spin_unlock_irqrestore (&ehci->lock, flags);
 160         return ret;
 161 }
 162 static DEVICE_ATTR(uframe_periodic_max, 0644, show_uframe_periodic_max, store_uframe_periodic_max);
 163
 164
 165 static 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);
 177 out:
 178         return i;
 179 }
 180
 181 static 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 }