drivers/ssb/sprom.c

   1 /*
   2  * Sonics Silicon Backplane
   3  * Common SPROM support routines
   4  *
   5  * Copyright (C) 2005-2008 Michael Buesch <mb@bu3sch.de>
   6  * Copyright (C) 2005 Martin Langer <martin-langer@gmx.de>
   7  * Copyright (C) 2005 Stefano Brivio <st3@riseup.net>
   8  * Copyright (C) 2005 Danny van Dyk <kugelfang@gentoo.org>
   9  * Copyright (C) 2005 Andreas Jaggi <andreas.jaggi@waterwave.ch>
  10  *
  11  * Licensed under the GNU/GPL. See COPYING for details.
  12  */
  13
  14 #include "ssb_private.h"
  15
  16 #include <linux/ctype.h>
  17
  18
  19 static const struct ssb_sprom *fallback_sprom;
  20
  21
  22 static int sprom2hex(const u16 *sprom, char *buf, size_t buf_len,
  23                      size_t sprom_size_words)
  24 {
  25         int i, pos = 0;
  26
  27         for (i = 0; i < sprom_size_words; i++)
  28                 pos += snprintf(buf + pos, buf_len - pos - 1,
  29                                 "%04X", swab16(sprom[i]) & 0xFFFF);
  30         pos += snprintf(buf + pos, buf_len - pos - 1, "\n");
  31
  32         return pos + 1;
  33 }
  34
  35 static int hex2sprom(u16 *sprom, const char *dump, size_t len,
  36                      size_t sprom_size_words)
  37 {
  38         char c, tmp[5] = { 0 };
  39         int err, cnt = 0;
  40         unsigned long parsed;
  41
  42         /* Strip whitespace at the end. */
  43         while (len) {
  44                 c = dump[len - 1];
  45                 if (!isspace(c) && c != '\0')
  46                         break;
  47                 len--;
  48         }
  49         /* Length must match exactly. */
  50         if (len != sprom_size_words * 4)
  51                 return -EINVAL;
  52
  53         while (cnt < sprom_size_words) {
  54                 memcpy(tmp, dump, 4);
  55                 dump += 4;
  56                 err = strict_strtoul(tmp, 16, &parsed);
  57                 if (err)
  58                         return err;
  59                 sprom[cnt++] = swab16((u16)parsed);
  60         }
  61
  62         return 0;
  63 }
  64
  65 /* Common sprom device-attribute show-handler */
  66 ssize_t ssb_attr_sprom_show(struct ssb_bus *bus, char *buf,
  67                             int (*sprom_read)(struct ssb_bus *bus, u16 *sprom))
  68 {
  69         u16 *sprom;
  70         int err = -ENOMEM;
  71         ssize_t count = 0;
  72         size_t sprom_size_words = bus->sprom_size;
  73
  74         sprom = kcalloc(sprom_size_words, sizeof(u16), GFP_KERNEL);
  75         if (!sprom)
  76                 goto out;
  77
  78         /* Use interruptible locking, as the SPROM write might
  79          * be holding the lock for several seconds. So allow userspace
  80          * to cancel operation. */
  81         err = -ERESTARTSYS;
  82         if (mutex_lock_interruptible(&bus->sprom_mutex))
  83                 goto out_kfree;
  84         err = sprom_read(bus, sprom);
  85         mutex_unlock(&bus->sprom_mutex);
  86
  87         if (!err)
  88                 count = sprom2hex(sprom, buf, PAGE_SIZE, sprom_size_words);
  89
  90 out_kfree:
  91         kfree(sprom);
  92 out:
  93         return err ? err : count;
  94 }
  95
  96 /* Common sprom device-attribute store-handler */
  97 ssize_t ssb_attr_sprom_store(struct ssb_bus *bus,
  98                              const char *buf, size_t count,
  99                              int (*sprom_check_crc)(const u16 *sprom, size_t size),
 100                              int (*sprom_write)(struct ssb_bus *bus, const u16 *sprom))
 101 {
 102         u16 *sprom;
 103         int res = 0, err = -ENOMEM;
 104         size_t sprom_size_words = bus->sprom_size;
 105         struct ssb_freeze_context freeze;
 106
 107         sprom = kcalloc(bus->sprom_size, sizeof(u16), GFP_KERNEL);
 108         if (!sprom)
 109                 goto out;
 110         err = hex2sprom(sprom, buf, count, sprom_size_words);
 111         if (err) {
 112                 err = -EINVAL;
 113                 goto out_kfree;
 114         }
 115         err = sprom_check_crc(sprom, sprom_size_words);
 116         if (err) {
 117                 err = -EINVAL;
 118                 goto out_kfree;
 119         }
 120
 121         /* Use interruptible locking, as the SPROM write might
 122          * be holding the lock for several seconds. So allow userspace
 123          * to cancel operation. */
 124         err = -ERESTARTSYS;
 125         if (mutex_lock_interruptible(&bus->sprom_mutex))
 126                 goto out_kfree;
 127         err = ssb_devices_freeze(bus, &freeze);
 128         if (err) {
 129                 ssb_printk(KERN_ERR PFX "SPROM write: Could not freeze all devices\n");
 130                 goto out_unlock;
 131         }
 132         res = sprom_write(bus, sprom);
 133         err = ssb_devices_thaw(&freeze);
 134         if (err)
 135                 ssb_printk(KERN_ERR PFX "SPROM write: Could not thaw all devices\n");
 136 out_unlock:
 137         mutex_unlock(&bus->sprom_mutex);
 138 out_kfree:
 139         kfree(sprom);
 140 out:
 141         if (res)
 142                 return res;
 143         return err ? err : count;
 144 }
 145
 146 /**
 147  * ssb_arch_set_fallback_sprom - Set a fallback SPROM for use if no SPROM is found.
 148  *
 149  * @sprom: The SPROM data structure to register.
 150  *
 151  * With this function the architecture implementation may register a fallback
 152  * SPROM data structure. The fallback is only used for PCI based SSB devices,
 153  * where no valid SPROM can be found in the shadow registers.
 154  *
 155  * This function is useful for weird architectures that have a half-assed SSB device
 156  * hardwired to their PCI bus.
 157  *
 158  * Note that it does only work with PCI attached SSB devices. PCMCIA devices currently
 159  * don't use this fallback.
 160  * Architectures must provide the SPROM for native SSB devices anyway,
 161  * so the fallback also isn't used for native devices.
 162  *
 163  * This function is available for architecture code, only. So it is not exported.
 164  */
 165 int ssb_arch_set_fallback_sprom(const struct ssb_sprom *sprom)
 166 {
 167         if (fallback_sprom)
 168                 return -EEXIST;
 169         fallback_sprom = sprom;
 170
 171         return 0;
 172 }
 173
 174 const struct ssb_sprom *ssb_get_fallback_sprom(void)
 175 {
 176         return fallback_sprom;
 177 }