drivers/mca/mca-legacy.c

   1 /* -*- mode: c; c-basic-offset: 8 -*- */
   2
   3 /*
   4  * MCA bus support functions for legacy (2.4) API.
   5  *
   6  * Legacy API means the API that operates in terms of MCA slot number
   7  *
   8  * (C) 2002 James Bottomley <James.Bottomley@HansenPartnership.com>
   9  *
  10 **-----------------------------------------------------------------------------
  11 **
  12 **  This program is free software; you can redistribute it and/or modify
  13 **  it under the terms of the GNU General Public License as published by
  14 **  the Free Software Foundation; either version 2 of the License, or
  15 **  (at your option) any later version.
  16 **
  17 **  This program is distributed in the hope that it will be useful,
  18 **  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 **  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 **  GNU General Public License for more details.
  21 **
  22 **  You should have received a copy of the GNU General Public License
  23 **  along with this program; if not, write to the Free Software
  24 **  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25 **
  26 **-----------------------------------------------------------------------------
  27  */
  28
  29 #include <linux/module.h>
  30 #include <linux/device.h>
  31 #include <linux/mca-legacy.h>
  32 #include <asm/io.h>
  33
  34 /* NOTE: This structure is stack allocated */
  35 struct mca_find_adapter_info {
  36         int                     id;
  37         int                     slot;
  38         struct mca_device       *mca_dev;
  39 };
  40
  41 /* The purpose of this iterator is to loop over all the devices and
  42  * find the one with the smallest slot number that's just greater than
  43  * or equal to the required slot with a matching id */
  44 static int mca_find_adapter_callback(struct device *dev, void *data)
  45 {
  46         struct mca_find_adapter_info *info = data;
  47         struct mca_device *mca_dev = to_mca_device(dev);
  48
  49         if(mca_dev->pos_id != info->id)
  50                 return 0;
  51
  52         if(mca_dev->slot < info->slot)
  53                 return 0;
  54
  55         if(!info->mca_dev || info->mca_dev->slot >= mca_dev->slot)
  56                 info->mca_dev = mca_dev;
  57
  58         return 0;
  59 }
  60
  61 /**
  62  *      mca_find_adapter - scan for adapters
  63  *      @id:    MCA identification to search for
  64  *      @start: starting slot
  65  *
  66  *      Search the MCA configuration for adapters matching the 16bit
  67  *      ID given. The first time it should be called with start as zero
  68  *      and then further calls made passing the return value of the
  69  *      previous call until %MCA_NOTFOUND is returned.
  70  *
  71  *      Disabled adapters are not reported.
  72  */
  73
  74 int mca_find_adapter(int id, int start)
  75 {
  76         struct mca_find_adapter_info info;
  77
  78         if(id == 0xffff)
  79                 return MCA_NOTFOUND;
  80
  81         info.slot = start;
  82         info.id = id;
  83         info.mca_dev = NULL;
  84
  85         for(;;) {
  86                 bus_for_each_dev(&mca_bus_type, NULL, &info, mca_find_adapter_callback);
  87
  88                 if(info.mca_dev == NULL)
  89                         return MCA_NOTFOUND;
  90
  91                 if(info.mca_dev->status != MCA_ADAPTER_DISABLED)
  92                         break;
  93
  94                 /* OK, found adapter but it was disabled.  Go around
  95                  * again, excluding the slot we just found */
  96
  97                 info.slot = info.mca_dev->slot + 1;
  98                 info.mca_dev = NULL;
  99         }
 100
 101         return info.mca_dev->slot;
 102 }
 103 EXPORT_SYMBOL(mca_find_adapter);
 104
 105 /*--------------------------------------------------------------------*/
 106
 107 /**
 108  *      mca_find_unused_adapter - scan for unused adapters
 109  *      @id:    MCA identification to search for
 110  *      @start: starting slot
 111  *
 112  *      Search the MCA configuration for adapters matching the 16bit
 113  *      ID given. The first time it should be called with start as zero
 114  *      and then further calls made passing the return value of the
 115  *      previous call until %MCA_NOTFOUND is returned.
 116  *
 117  *      Adapters that have been claimed by drivers and those that
 118  *      are disabled are not reported. This function thus allows a driver
 119  *      to scan for further cards when some may already be driven.
 120  */
 121
 122 int mca_find_unused_adapter(int id, int start)
 123 {
 124         struct mca_find_adapter_info info = { 0 };
 125
 126         if (!MCA_bus || id == 0xffff)
 127                 return MCA_NOTFOUND;
 128
 129         info.slot = start;
 130         info.id = id;
 131         info.mca_dev = NULL;
 132
 133         for(;;) {
 134                 bus_for_each_dev(&mca_bus_type, NULL, &info, mca_find_adapter_callback);
 135
 136                 if(info.mca_dev == NULL)
 137                         return MCA_NOTFOUND;
 138
 139                 if(info.mca_dev->status != MCA_ADAPTER_DISABLED
 140                    && !info.mca_dev->driver_loaded)
 141                         break;
 142
 143                 /* OK, found adapter but it was disabled or already in
 144                  * use.  Go around again, excluding the slot we just
 145                  * found */
 146
 147                 info.slot = info.mca_dev->slot + 1;
 148                 info.mca_dev = NULL;
 149         }
 150
 151         return info.mca_dev->slot;
 152 }
 153 EXPORT_SYMBOL(mca_find_unused_adapter);
 154
 155 /* NOTE: stack allocated structure */
 156 struct mca_find_device_by_slot_info {
 157         int                     slot;
 158         struct mca_device       *mca_dev;
 159 };
 160
 161 static int mca_find_device_by_slot_callback(struct device *dev, void *data)
 162 {
 163         struct mca_find_device_by_slot_info *info = data;
 164         struct mca_device *mca_dev = to_mca_device(dev);
 165
 166         if(mca_dev->slot == info->slot)
 167                 info->mca_dev = mca_dev;
 168
 169         return 0;
 170 }
 171
 172 struct mca_device *mca_find_device_by_slot(int slot)
 173 {
 174         struct mca_find_device_by_slot_info info;
 175
 176         info.slot = slot;
 177         info.mca_dev = NULL;
 178
 179         bus_for_each_dev(&mca_bus_type, NULL, &info, mca_find_device_by_slot_callback);
 180
 181         return info.mca_dev;
 182 }
 183
 184 /**
 185  *      mca_read_stored_pos - read POS register from boot data
 186  *      @slot: slot number to read from
 187  *      @reg:  register to read from
 188  *
 189  *      Fetch a POS value that was stored at boot time by the kernel
 190  *      when it scanned the MCA space. The register value is returned.
 191  *      Missing or invalid registers report 0.
 192  */
 193 unsigned char mca_read_stored_pos(int slot, int reg)
 194 {
 195         struct mca_device *mca_dev = mca_find_device_by_slot(slot);
 196
 197         if(!mca_dev)
 198                 return 0;
 199
 200         return mca_device_read_stored_pos(mca_dev, reg);
 201 }
 202 EXPORT_SYMBOL(mca_read_stored_pos);
 203
 204
 205 /**
 206  *      mca_read_pos - read POS register from card
 207  *      @slot: slot number to read from
 208  *      @reg:  register to read from
 209  *
 210  *      Fetch a POS value directly from the hardware to obtain the
 211  *      current value. This is much slower than mca_read_stored_pos and
 212  *      may not be invoked from interrupt context. It handles the
 213  *      deep magic required for onboard devices transparently.
 214  */
 215
 216 unsigned char mca_read_pos(int slot, int reg)
 217 {
 218         struct mca_device *mca_dev = mca_find_device_by_slot(slot);
 219
 220         if(!mca_dev)
 221                 return 0;
 222
 223         return mca_device_read_pos(mca_dev, reg);
 224 }
 225 EXPORT_SYMBOL(mca_read_pos);
 226
 227
 228 /**
 229  *      mca_write_pos - read POS register from card
 230  *      @slot: slot number to read from
 231  *      @reg:  register to read from
 232  *      @byte: byte to write to the POS registers
 233  *
 234  *      Store a POS value directly from the hardware. You should not
 235  *      normally need to use this function and should have a very good
 236  *      knowledge of MCA bus before you do so. Doing this wrongly can
 237  *      damage the hardware.
 238  *
 239  *      This function may not be used from interrupt context.
 240  *
 241  *      Note that this a technically a Bad Thing, as IBM tech stuff says
 242  *      you should only set POS values through their utilities.
 243  *      However, some devices such as the 3c523 recommend that you write
 244  *      back some data to make sure the configuration is consistent.
 245  *      I'd say that IBM is right, but I like my drivers to work.
 246  *
 247  *      This function can't do checks to see if multiple devices end up
 248  *      with the same resources, so you might see magic smoke if someone
 249  *      screws up.
 250  */
 251
 252 void mca_write_pos(int slot, int reg, unsigned char byte)
 253 {
 254         struct mca_device *mca_dev = mca_find_device_by_slot(slot);
 255
 256         if(!mca_dev)
 257                 return;
 258
 259         mca_device_write_pos(mca_dev, reg, byte);
 260 }
 261 EXPORT_SYMBOL(mca_write_pos);
 262
 263 /**
 264  *      mca_set_adapter_name - Set the description of the card
 265  *      @slot: slot to name
 266  *      @name: text string for the namen
 267  *
 268  *      This function sets the name reported via /proc for this
 269  *      adapter slot. This is for user information only. Setting a
 270  *      name deletes any previous name.
 271  */
 272
 273 void mca_set_adapter_name(int slot, char* name)
 274 {
 275         struct mca_device *mca_dev = mca_find_device_by_slot(slot);
 276
 277         if(!mca_dev)
 278                 return;
 279
 280         mca_device_set_name(mca_dev, name);
 281 }
 282 EXPORT_SYMBOL(mca_set_adapter_name);
 283
 284 /**
 285  *      mca_mark_as_used - claim an MCA device
 286  *      @slot:  slot to claim
 287  *      FIXME:  should we make this threadsafe
 288  *
 289  *      Claim an MCA slot for a device driver. If the
 290  *      slot is already taken the function returns 1,
 291  *      if it is not taken it is claimed and 0 is
 292  *      returned.
 293  */
 294
 295 int mca_mark_as_used(int slot)
 296 {
 297         struct mca_device *mca_dev = mca_find_device_by_slot(slot);
 298
 299         if(!mca_dev)
 300                 /* FIXME: this is actually a severe error */
 301                 return 1;
 302
 303         if(mca_device_claimed(mca_dev))
 304                 return 1;
 305
 306         mca_device_set_claim(mca_dev, 1);
 307
 308         return 0;
 309 }
 310 EXPORT_SYMBOL(mca_mark_as_used);
 311
 312 /**
 313  *      mca_mark_as_unused - release an MCA device
 314  *      @slot:  slot to claim
 315  *
 316  *      Release the slot for other drives to use.
 317  */
 318
 319 void mca_mark_as_unused(int slot)
 320 {
 321         struct mca_device *mca_dev = mca_find_device_by_slot(slot);
 322
 323         if(!mca_dev)
 324                 return;
 325
 326         mca_device_set_claim(mca_dev, 0);
 327 }
 328 EXPORT_SYMBOL(mca_mark_as_unused);
 329