drivers/ssb/sprom.c

   1 /*
   2  * Sonics Silicon Backplane
   3  * Common SPROM support routines
   4  *
   5  * Copyright (C) 2005-2008 Michael Buesch <m@bues.ch>
   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 #include <linux/slab.h>
  18
  19
  20 static int(*get_fallback_sprom)(struct ssb_bus *dev, struct ssb_sprom *out);
  21
  22
  23 static int sprom2hex(const u16 *sprom, char *buf, size_t buf_len,
  24                      size_t sprom_size_words)
  25 {
  26         int i, pos = 0;
  27
  28         for (i = 0; i < sprom_size_words; i++)
  29                 pos += scnprintf(buf + pos, buf_len - pos - 1,
  30                                 "%04X", swab16(sprom[i]) & 0xFFFF);
  31         pos += scnprintf(buf + pos, buf_len - pos - 1, "\n");
  32
  33         return pos + 1;
  34 }
  35
  36 static int hex2sprom(u16 *sprom, const char *dump, size_t len,
  37                      size_t sprom_size_words)
  38 {
  39         char c, tmp[5] = { 0 };
  40         int err, cnt = 0;
  41         unsigned long parsed;
  42
  43         /* Strip whitespace at the end. */
  44         while (len) {
  45                 c = dump[len - 1];
  46                 if (!isspace(c) && c != '\0')
  47                         break;
  48                 len--;
  49         }
  50         /* Length must match exactly. */
  51         if (len != sprom_size_words * 4)
  52                 return -EINVAL;
  53
  54         while (cnt < sprom_size_words) {
  55                 memcpy(tmp, dump, 4);
  56                 dump += 4;
  57                 err = kstrtoul(tmp, 16, &parsed);
  58                 if (err)
  59                         return err;
  60                 sprom[cnt++] = swab16((u16)parsed);
  61         }
  62
  63         return 0;
  64 }
  65
  66 /* Common sprom device-attribute show-handler */
  67 ssize_t ssb_attr_sprom_show(struct ssb_bus *bus, char *buf,
  68                             int (*sprom_read)(struct ssb_bus *bus, u16 *sprom))
  69 {
  70         u16 *sprom;
  71         int err = -ENOMEM;
  72         ssize_t count = 0;
  73         size_t sprom_size_words = bus->sprom_size;
  74
  75         sprom = kcalloc(sprom_size_words, sizeof(u16), GFP_KERNEL);
  76         if (!sprom)
  77                 goto out;
  78
  79         /* Use interruptible locking, as the SPROM write might
  80          * be holding the lock for several seconds. So allow userspace
  81          * to cancel operation.
  82          */
  83         err = -ERESTARTSYS;
  84         if (mutex_lock_interruptible(&bus->sprom_mutex))
  85                 goto out_kfree;
  86         err = sprom_read(bus, sprom);
  87         mutex_unlock(&bus->sprom_mutex);
  88
  89         if (!err)
  90                 count = sprom2hex(sprom, buf, PAGE_SIZE, sprom_size_words);
  91
  92 out_kfree:
  93         kfree(sprom);
  94 out:
  95         return err ? err : count;
  96 }
  97
  98 /* Common sprom device-attribute store-handler */
  99 ssize_t ssb_attr_sprom_store(struct ssb_bus *bus,
 100                              const char *buf, size_t count,
 101                              int (*sprom_check_crc)(const u16 *sprom, size_t size),
 102                              int (*sprom_write)(struct ssb_bus *bus, const u16 *sprom))
 103 {
 104         u16 *sprom;
 105         int res = 0, err = -ENOMEM;
 106         size_t sprom_size_words = bus->sprom_size;
 107         struct ssb_freeze_context freeze;
 108
 109         sprom = kcalloc(bus->sprom_size, sizeof(u16), GFP_KERNEL);
 110         if (!sprom)
 111                 goto out;
 112         err = hex2sprom(sprom, buf, count, sprom_size_words);
 113         if (err) {
 114                 err = -EINVAL;
 115                 goto out_kfree;
 116         }
 117         err = sprom_check_crc(sprom, sprom_size_words);
 118         if (err) {
 119                 err = -EINVAL;
 120                 goto out_kfree;
 121         }
 122
 123         /* Use interruptible locking, as the SPROM write might
 124          * be holding the lock for several seconds. So allow userspace
 125          * to cancel operation.
 126          */
 127         err = -ERESTARTSYS;
 128         if (mutex_lock_interruptible(&bus->sprom_mutex))
 129                 goto out_kfree;
 130         err = ssb_devices_freeze(bus, &freeze);
 131         if (err) {
 132                 pr_err("SPROM write: Could not freeze all devices\n");
 133                 goto out_unlock;
 134         }
 135         res = sprom_write(bus, sprom);
 136         err = ssb_devices_thaw(&freeze);
 137         if (err)
 138                 pr_err("SPROM write: Could not thaw all devices\n");
 139 out_unlock:
 140         mutex_unlock(&bus->sprom_mutex);
 141 out_kfree:
 142         kfree(sprom);
 143 out:
 144         if (res)
 145                 return res;
 146         return err ? err : count;
 147 }
 148
 149 /**
 150  * ssb_arch_register_fallback_sprom - Registers a method providing a
 151  * fallback SPROM if no SPROM is found.
 152  *
 153  * @sprom_callback: The callback function.
 154  *
 155  * With this function the architecture implementation may register a
 156  * callback handler which fills the SPROM data structure. The fallback is
 157  * only used for PCI based SSB devices, where no valid SPROM can be found
 158  * in the shadow registers.
 159  *
 160  * This function is useful for weird architectures that have a half-assed
 161  * SSB device hardwired to their PCI bus.
 162  *
 163  * Note that it does only work with PCI attached SSB devices. PCMCIA
 164  * devices currently don't use this fallback.
 165  * Architectures must provide the SPROM for native SSB devices anyway, so
 166  * the fallback also isn't used for native devices.
 167  *
 168  * This function is available for architecture code, only. So it is not
 169  * exported.
 170  */
 171 int ssb_arch_register_fallback_sprom(int (*sprom_callback)(struct ssb_bus *bus,
 172                                      struct ssb_sprom *out))
 173 {
 174         if (get_fallback_sprom)
 175                 return -EEXIST;
 176         get_fallback_sprom = sprom_callback;
 177
 178         return 0;
 179 }
 180
 181 int ssb_fill_sprom_with_fallback(struct ssb_bus *bus, struct ssb_sprom *out)
 182 {
 183         if (!get_fallback_sprom)
 184                 return -ENOENT;
 185
 186         return get_fallback_sprom(bus, out);
 187 }
 188
 189 /* https://bcm-v4.sipsolutions.net/802.11/IsSpromAvailable */
 190 bool ssb_is_sprom_available(struct ssb_bus *bus)
 191 {
 192         /* status register only exists on chipcomon rev >= 11 and we need check
 193          * for >= 31 only
 194          */
 195         /* this routine differs from specs as we do not access SPROM directly
 196          * on PCMCIA
 197          */
 198         if (bus->bustype == SSB_BUSTYPE_PCI &&
 199             bus->chipco.dev &&  /* can be unavailable! */
 200             bus->chipco.dev->id.revision >= 31)
 201                 return bus->chipco.capabilities & SSB_CHIPCO_CAP_SPROM;
 202
 203         return true;
 204 }