drivers/i2c/busses/i2c-powermac.c

   1 /*
   2     i2c Support for Apple SMU Controller
   3
   4     Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp.
   5                        <benh@kernel.crashing.org>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 */
  22
  23 #include <linux/module.h>
  24 #include <linux/kernel.h>
  25 #include <linux/types.h>
  26 #include <linux/i2c.h>
  27 #include <linux/init.h>
  28 #include <linux/device.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/of_irq.h>
  31 #include <asm/prom.h>
  32 #include <asm/pmac_low_i2c.h>
  33
  34 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
  35 MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
  36 MODULE_LICENSE("GPL");
  37
  38 /*
  39  * SMBUS-type transfer entrypoint
  40  */
  41 static s32 i2c_powermac_smbus_xfer(     struct i2c_adapter*     adap,
  42                                         u16                     addr,
  43                                         unsigned short          flags,
  44                                         char                    read_write,
  45                                         u8                      command,
  46                                         int                     size,
  47                                         union i2c_smbus_data*   data)
  48 {
  49         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
  50         int                     rc = 0;
  51         int                     read = (read_write == I2C_SMBUS_READ);
  52         int                     addrdir = (addr << 1) | read;
  53         int                     mode, subsize, len;
  54         u32                     subaddr;
  55         u8                      *buf;
  56         u8                      local[2];
  57
  58         if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) {
  59                 mode = pmac_i2c_mode_std;
  60                 subsize = 0;
  61                 subaddr = 0;
  62         } else {
  63                 mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub;
  64                 subsize = 1;
  65                 subaddr = command;
  66         }
  67
  68         switch (size) {
  69         case I2C_SMBUS_QUICK:
  70                 buf = NULL;
  71                 len = 0;
  72                 break;
  73         case I2C_SMBUS_BYTE:
  74         case I2C_SMBUS_BYTE_DATA:
  75                 buf = &data->byte;
  76                 len = 1;
  77                 break;
  78         case I2C_SMBUS_WORD_DATA:
  79                 if (!read) {
  80                         local[0] = data->word & 0xff;
  81                         local[1] = (data->word >> 8) & 0xff;
  82                 }
  83                 buf = local;
  84                 len = 2;
  85                 break;
  86
  87         /* Note that these are broken vs. the expected smbus API where
  88          * on reads, the length is actually returned from the function,
  89          * but I think the current API makes no sense and I don't want
  90          * any driver that I haven't verified for correctness to go
  91          * anywhere near a pmac i2c bus anyway ...
  92          *
  93          * I'm also not completely sure what kind of phases to do between
  94          * the actual command and the data (what I am _supposed_ to do that
  95          * is). For now, I assume writes are a single stream and reads have
  96          * a repeat start/addr phase (but not stop in between)
  97          */
  98         case I2C_SMBUS_BLOCK_DATA:
  99                 buf = data->block;
 100                 len = data->block[0] + 1;
 101                 break;
 102         case I2C_SMBUS_I2C_BLOCK_DATA:
 103                 buf = &data->block[1];
 104                 len = data->block[0];
 105                 break;
 106
 107         default:
 108                 return -EINVAL;
 109         }
 110
 111         rc = pmac_i2c_open(bus, 0);
 112         if (rc) {
 113                 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
 114                 return rc;
 115         }
 116
 117         rc = pmac_i2c_setmode(bus, mode);
 118         if (rc) {
 119                 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
 120                         mode, rc);
 121                 goto bail;
 122         }
 123
 124         rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len);
 125         if (rc) {
 126                 if (rc == -ENXIO)
 127                         dev_dbg(&adap->dev,
 128                                 "I2C transfer at 0x%02x failed, size %d, "
 129                                 "err %d\n", addrdir >> 1, size, rc);
 130                 else
 131                         dev_err(&adap->dev,
 132                                 "I2C transfer at 0x%02x failed, size %d, "
 133                                 "err %d\n", addrdir >> 1, size, rc);
 134                 goto bail;
 135         }
 136
 137         if (size == I2C_SMBUS_WORD_DATA && read) {
 138                 data->word = ((u16)local[1]) << 8;
 139                 data->word |= local[0];
 140         }
 141
 142  bail:
 143         pmac_i2c_close(bus);
 144         return rc;
 145 }
 146
 147 /*
 148  * Generic i2c master transfer entrypoint. This driver only support single
 149  * messages (for "lame i2c" transfers). Anything else should use the smbus
 150  * entry point
 151  */
 152 static int i2c_powermac_master_xfer(    struct i2c_adapter *adap,
 153                                         struct i2c_msg *msgs,
 154                                         int num)
 155 {
 156         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
 157         int                     rc = 0;
 158         int                     read;
 159         int                     addrdir;
 160
 161         if (num != 1) {
 162                 dev_err(&adap->dev,
 163                         "Multi-message I2C transactions not supported\n");
 164                 return -EOPNOTSUPP;
 165         }
 166
 167         if (msgs->flags & I2C_M_TEN)
 168                 return -EINVAL;
 169         read = (msgs->flags & I2C_M_RD) != 0;
 170         addrdir = (msgs->addr << 1) | read;
 171
 172         rc = pmac_i2c_open(bus, 0);
 173         if (rc) {
 174                 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
 175                 return rc;
 176         }
 177         rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
 178         if (rc) {
 179                 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
 180                         pmac_i2c_mode_std, rc);
 181                 goto bail;
 182         }
 183         rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
 184         if (rc < 0) {
 185                 if (rc == -ENXIO)
 186                         dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
 187                                 addrdir & 1 ? "read from" : "write to",
 188                                 addrdir >> 1, rc);
 189                 else
 190                         dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
 191                                 addrdir & 1 ? "read from" : "write to",
 192                                 addrdir >> 1, rc);
 193         }
 194  bail:
 195         pmac_i2c_close(bus);
 196         return rc < 0 ? rc : 1;
 197 }
 198
 199 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
 200 {
 201         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 202                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 203                 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
 204 }
 205
 206 /* For now, we only handle smbus */
 207 static const struct i2c_algorithm i2c_powermac_algorithm = {
 208         .smbus_xfer     = i2c_powermac_smbus_xfer,
 209         .master_xfer    = i2c_powermac_master_xfer,
 210         .functionality  = i2c_powermac_func,
 211 };
 212
 213
 214 static int i2c_powermac_remove(struct platform_device *dev)
 215 {
 216         struct i2c_adapter      *adapter = platform_get_drvdata(dev);
 217
 218         i2c_del_adapter(adapter);
 219         memset(adapter, 0, sizeof(*adapter));
 220
 221         return 0;
 222 }
 223
 224 static u32 i2c_powermac_get_addr(struct i2c_adapter *adap,
 225                                            struct pmac_i2c_bus *bus,
 226                                            struct device_node *node)
 227 {
 228         const __be32 *prop;
 229         int len;
 230
 231         /* First check for valid "reg" */
 232         prop = of_get_property(node, "reg", &len);
 233         if (prop && (len >= sizeof(int)))
 234                 return (be32_to_cpup(prop) & 0xff) >> 1;
 235
 236         /* Then check old-style "i2c-address" */
 237         prop = of_get_property(node, "i2c-address", &len);
 238         if (prop && (len >= sizeof(int)))
 239                 return (be32_to_cpup(prop) & 0xff) >> 1;
 240
 241         /* Now handle some devices with missing "reg" properties */
 242         if (!strcmp(node->name, "cereal"))
 243                 return 0x60;
 244         else if (!strcmp(node->name, "deq"))
 245                 return 0x34;
 246
 247         dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name);
 248
 249         return 0xffffffff;
 250 }
 251
 252 static void i2c_powermac_create_one(struct i2c_adapter *adap,
 253                                               const char *type,
 254                                               u32 addr)
 255 {
 256         struct i2c_board_info info = {};
 257         struct i2c_client *newdev;
 258
 259         strncpy(info.type, type, sizeof(info.type));
 260         info.addr = addr;
 261         newdev = i2c_new_device(adap, &info);
 262         if (!newdev)
 263                 dev_err(&adap->dev,
 264                         "i2c-powermac: Failure to register missing %s\n",
 265                         type);
 266 }
 267
 268 static void i2c_powermac_add_missing(struct i2c_adapter *adap,
 269                                                struct pmac_i2c_bus *bus,
 270                                                bool found_onyx)
 271 {
 272         struct device_node *busnode = pmac_i2c_get_bus_node(bus);
 273         int rc;
 274
 275         /* Check for the onyx audio codec */
 276 #define ONYX_REG_CONTROL                67
 277         if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
 278                 union i2c_smbus_data data;
 279
 280                 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
 281                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
 282                                     &data);
 283                 if (rc >= 0)
 284                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
 285
 286                 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
 287                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
 288                                     &data);
 289                 if (rc >= 0)
 290                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
 291         }
 292 }
 293
 294 static bool i2c_powermac_get_type(struct i2c_adapter *adap,
 295                                             struct device_node *node,
 296                                             u32 addr, char *type, int type_size)
 297 {
 298         char tmp[16];
 299
 300         /* Note: we to _NOT_ want the standard
 301          * i2c drivers to match with any of our powermac stuff
 302          * unless they have been specifically modified to handle
 303          * it on a case by case basis. For example, for thermal
 304          * control, things like lm75 etc... shall match with their
 305          * corresponding windfarm drivers, _NOT_ the generic ones,
 306          * so we force a prefix of AAPL, onto the modalias to
 307          * make that happen
 308          */
 309
 310         /* First try proper modalias */
 311         if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
 312                 snprintf(type, type_size, "MAC,%s", tmp);
 313                 return true;
 314         }
 315
 316         /* Now look for known workarounds */
 317         if (!strcmp(node->name, "deq")) {
 318                 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
 319                 if (addr == 0x34) {
 320                         snprintf(type, type_size, "MAC,tas3001");
 321                         return true;
 322                 } else if (addr == 0x35) {
 323                         snprintf(type, type_size, "MAC,tas3004");
 324                         return true;
 325                 }
 326         }
 327
 328         dev_err(&adap->dev, "i2c-powermac: modalias failure"
 329                 " on %s\n", node->full_name);
 330         return false;
 331 }
 332
 333 static void i2c_powermac_register_devices(struct i2c_adapter *adap,
 334                                                     struct pmac_i2c_bus *bus)
 335 {
 336         struct i2c_client *newdev;
 337         struct device_node *node;
 338         bool found_onyx = 0;
 339
 340         /*
 341          * In some cases we end up with the via-pmu node itself, in this
 342          * case we skip this function completely as the device-tree will
 343          * not contain anything useful.
 344          */
 345         if (!strcmp(adap->dev.of_node->name, "via-pmu"))
 346                 return;
 347
 348         for_each_child_of_node(adap->dev.of_node, node) {
 349                 struct i2c_board_info info = {};
 350                 u32 addr;
 351
 352                 /* Get address & channel */
 353                 addr = i2c_powermac_get_addr(adap, bus, node);
 354                 if (addr == 0xffffffff)
 355                         continue;
 356
 357                 /* Multibus setup, check channel */
 358                 if (!pmac_i2c_match_adapter(node, adap))
 359                         continue;
 360
 361                 dev_dbg(&adap->dev, "i2c-powermac: register %s\n",
 362                         node->full_name);
 363
 364                 /*
 365                  * Keep track of some device existence to handle
 366                  * workarounds later.
 367                  */
 368                 if (of_device_is_compatible(node, "pcm3052"))
 369                         found_onyx = true;
 370
 371                 /* Make up a modalias */
 372                 if (!i2c_powermac_get_type(adap, node, addr,
 373                                            info.type, sizeof(info.type))) {
 374                         continue;
 375                 }
 376
 377                 /* Fill out the rest of the info structure */
 378                 info.addr = addr;
 379                 info.irq = irq_of_parse_and_map(node, 0);
 380                 info.of_node = of_node_get(node);
 381
 382                 newdev = i2c_new_device(adap, &info);
 383                 if (!newdev) {
 384                         dev_err(&adap->dev, "i2c-powermac: Failure to register"
 385                                 " %s\n", node->full_name);
 386                         of_node_put(node);
 387                         /* We do not dispose of the interrupt mapping on
 388                          * purpose. It's not necessary (interrupt cannot be
 389                          * re-used) and somebody else might have grabbed it
 390                          * via direct DT lookup so let's not bother
 391                          */
 392                         continue;
 393                 }
 394         }
 395
 396         /* Additional workarounds */
 397         i2c_powermac_add_missing(adap, bus, found_onyx);
 398 }
 399
 400 static int i2c_powermac_probe(struct platform_device *dev)
 401 {
 402         struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev);
 403         struct device_node *parent = NULL;
 404         struct i2c_adapter *adapter;
 405         const char *basename;
 406         int rc;
 407
 408         if (bus == NULL)
 409                 return -EINVAL;
 410         adapter = pmac_i2c_get_adapter(bus);
 411
 412         /* Ok, now we need to make up a name for the interface that will
 413          * match what we used to do in the past, that is basically the
 414          * controller's parent device node for keywest. PMU didn't have a
 415          * naming convention and SMU has a different one
 416          */
 417         switch(pmac_i2c_get_type(bus)) {
 418         case pmac_i2c_bus_keywest:
 419                 parent = of_get_parent(pmac_i2c_get_controller(bus));
 420                 if (parent == NULL)
 421                         return -EINVAL;
 422                 basename = parent->name;
 423                 break;
 424         case pmac_i2c_bus_pmu:
 425                 basename = "pmu";
 426                 break;
 427         case pmac_i2c_bus_smu:
 428                 /* This is not what we used to do but I'm fixing drivers at
 429                  * the same time as this change
 430                  */
 431                 basename = "smu";
 432                 break;
 433         default:
 434                 return -EINVAL;
 435         }
 436         snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
 437                  pmac_i2c_get_channel(bus));
 438         of_node_put(parent);
 439
 440         platform_set_drvdata(dev, adapter);
 441         adapter->algo = &i2c_powermac_algorithm;
 442         i2c_set_adapdata(adapter, bus);
 443         adapter->dev.parent = &dev->dev;
 444
 445         /* Clear of_node to skip automatic registration of i2c child nodes */
 446         adapter->dev.of_node = NULL;
 447         rc = i2c_add_adapter(adapter);
 448         if (rc) {
 449                 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
 450                        "failed\n", adapter->name);
 451                 memset(adapter, 0, sizeof(*adapter));
 452                 return rc;
 453         }
 454
 455         printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
 456
 457         /* Use custom child registration due to Apple device-tree funkyness */
 458         adapter->dev.of_node = dev->dev.of_node;
 459         i2c_powermac_register_devices(adapter, bus);
 460
 461         return 0;
 462 }
 463
 464 static struct platform_driver i2c_powermac_driver = {
 465         .probe = i2c_powermac_probe,
 466         .remove = i2c_powermac_remove,
 467         .driver = {
 468                 .name = "i2c-powermac",
 469                 .bus = &platform_bus_type,
 470         },
 471 };
 472
 473 module_platform_driver(i2c_powermac_driver);
 474
 475 MODULE_ALIAS("platform:i2c-powermac");