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
  17 static const struct ssb_sprom *fallback_sprom;
  18
  19
  20 static int sprom2hex(const u16 *sprom, char *buf, size_t buf_len,
  21                      size_t sprom_size_words)
  22 {
  23         int i, pos = 0;
  24
  25         for (i = 0; i < sprom_size_words; i++)
  26                 pos += snprintf(buf + pos, buf_len - pos - 1,
  27                                 "%04X", swab16(sprom[i]) & 0xFFFF);
  28         pos += snprintf(buf + pos, buf_len - pos - 1, "\n");
  29
  30         return pos + 1;
  31 }
  32
  33 static int hex2sprom(u16 *sprom, const char *dump, size_t len,
  34                      size_t sprom_size_words)
  35 {
  36         char tmp[5] = { 0 };
  37         int cnt = 0;
  38         unsigned long parsed;
  39
  40         if (len < sprom_size_words * 2)
  41                 return -EINVAL;
  42
  43         while (cnt < sprom_size_words) {
  44                 memcpy(tmp, dump, 4);
  45                 dump += 4;
  46                 parsed = simple_strtoul(tmp, NULL, 16);
  47                 sprom[cnt++] = swab16((u16)parsed);
  48         }
  49
  50         return 0;
  51 }
  52
  53 /* Common sprom device-attribute show-handler */
  54 ssize_t ssb_attr_sprom_show(struct ssb_bus *bus, char *buf,
  55                             int (*sprom_read)(struct ssb_bus *bus, u16 *sprom))
  56 {
  57         u16 *sprom;
  58         int err = -ENOMEM;
  59         ssize_t count = 0;
  60         size_t sprom_size_words = bus->sprom_size;
  61
  62         sprom = kcalloc(sprom_size_words, sizeof(u16), GFP_KERNEL);
  63         if (!sprom)
  64                 goto out;
  65
  66         /* Use interruptible locking, as the SPROM write might
  67          * be holding the lock for several seconds. So allow userspace
  68          * to cancel operation. */
  69         err = -ERESTARTSYS;
  70         if (mutex_lock_interruptible(&bus->sprom_mutex))
  71                 goto out_kfree;
  72         err = sprom_read(bus, sprom);
  73         mutex_unlock(&bus->sprom_mutex);
  74
  75         if (!err)
  76                 count = sprom2hex(sprom, buf, PAGE_SIZE, sprom_size_words);
  77
  78 out_kfree:
  79         kfree(sprom);
  80 out:
  81         return err ? err : count;
  82 }
  83
  84 /* Common sprom device-attribute store-handler */
  85 ssize_t ssb_attr_sprom_store(struct ssb_bus *bus,
  86                              const char *buf, size_t count,
  87                              int (*sprom_check_crc)(const u16 *sprom, size_t size),
  88                              int (*sprom_write)(struct ssb_bus *bus, const u16 *sprom))
  89 {
  90         u16 *sprom;
  91         int res = 0, err = -ENOMEM;
  92         size_t sprom_size_words = bus->sprom_size;
  93
  94         sprom = kcalloc(bus->sprom_size, sizeof(u16), GFP_KERNEL);
  95         if (!sprom)
  96                 goto out;
  97         err = hex2sprom(sprom, buf, count, sprom_size_words);
  98         if (err) {
  99                 err = -EINVAL;
 100                 goto out_kfree;
 101         }
 102         err = sprom_check_crc(sprom, sprom_size_words);
 103         if (err) {
 104                 err = -EINVAL;
 105                 goto out_kfree;
 106         }
 107
 108         /* Use interruptible locking, as the SPROM write might
 109          * be holding the lock for several seconds. So allow userspace
 110          * to cancel operation. */
 111         err = -ERESTARTSYS;
 112         if (mutex_lock_interruptible(&bus->sprom_mutex))
 113                 goto out_kfree;
 114         err = ssb_devices_freeze(bus);
 115         if (err == -EOPNOTSUPP) {
 116                 ssb_printk(KERN_ERR PFX "SPROM write: Could not freeze devices. "
 117                            "No suspend support. Is CONFIG_PM enabled?\n");
 118                 goto out_unlock;
 119         }
 120         if (err) {
 121                 ssb_printk(KERN_ERR PFX "SPROM write: Could not freeze all devices\n");
 122                 goto out_unlock;
 123         }
 124         res = sprom_write(bus, sprom);
 125         err = ssb_devices_thaw(bus);
 126         if (err)
 127                 ssb_printk(KERN_ERR PFX "SPROM write: Could not thaw all devices\n");
 128 out_unlock:
 129         mutex_unlock(&bus->sprom_mutex);
 130 out_kfree:
 131         kfree(sprom);
 132 out:
 133         if (res)
 134                 return res;
 135         return err ? err : count;
 136 }
 137
 138 /**
 139  * ssb_arch_set_fallback_sprom - Set a fallback SPROM for use if no SPROM is found.
 140  *
 141  * @sprom: The SPROM data structure to register.
 142  *
 143  * With this function the architecture implementation may register a fallback
 144  * SPROM data structure. The fallback is only used for PCI based SSB devices,
 145  * where no valid SPROM can be found in the shadow registers.
 146  *
 147  * This function is useful for weird architectures that have a half-assed SSB device
 148  * hardwired to their PCI bus.
 149  *
 150  * Note that it does only work with PCI attached SSB devices. PCMCIA devices currently
 151  * don't use this fallback.
 152  * Architectures must provide the SPROM for native SSB devices anyway,
 153  * so the fallback also isn't used for native devices.
 154  *
 155  * This function is available for architecture code, only. So it is not exported.
 156  */
 157 int ssb_arch_set_fallback_sprom(const struct ssb_sprom *sprom)
 158 {
 159         if (fallback_sprom)
 160                 return -EEXIST;
 161         fallback_sprom = sprom;
 162
 163         return 0;
 164 }
 165
 166 const struct ssb_sprom *ssb_get_fallback_sprom(void)
 167 {
 168         return fallback_sprom;
 169 }