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 */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/types.h>
  22 #include <linux/i2c.h>
  23 #include <linux/device.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/of_irq.h>
  26 #include <asm/prom.h>
  27 #include <asm/pmac_low_i2c.h>
  28
  29 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
  30 MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
  31 MODULE_LICENSE("GPL");
  32
  33 /*
  34  * SMBUS-type transfer entrypoint
  35  */
  36 static s32 i2c_powermac_smbus_xfer(     struct i2c_adapter*     adap,
  37                                         u16                     addr,
  38                                         unsigned short          flags,
  39                                         char                    read_write,
  40                                         u8                      command,
  41                                         int                     size,
  42                                         union i2c_smbus_data*   data)
  43 {
  44         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
  45         int                     rc = 0;
  46         int                     read = (read_write == I2C_SMBUS_READ);
  47         int                     addrdir = (addr << 1) | read;
  48         int                     mode, subsize, len;
  49         u32                     subaddr;
  50         u8                      *buf;
  51         u8                      local[2];
  52
  53         if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) {
  54                 mode = pmac_i2c_mode_std;
  55                 subsize = 0;
  56                 subaddr = 0;
  57         } else {
  58                 mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub;
  59                 subsize = 1;
  60                 subaddr = command;
  61         }
  62
  63         switch (size) {
  64         case I2C_SMBUS_QUICK:
  65                 buf = NULL;
  66                 len = 0;
  67                 break;
  68         case I2C_SMBUS_BYTE:
  69         case I2C_SMBUS_BYTE_DATA:
  70                 buf = &data->byte;
  71                 len = 1;
  72                 break;
  73         case I2C_SMBUS_WORD_DATA:
  74                 if (!read) {
  75                         local[0] = data->word & 0xff;
  76                         local[1] = (data->word >> 8) & 0xff;
  77                 }
  78                 buf = local;
  79                 len = 2;
  80                 break;
  81
  82         /* Note that these are broken vs. the expected smbus API where
  83          * on reads, the length is actually returned from the function,
  84          * but I think the current API makes no sense and I don't want
  85          * any driver that I haven't verified for correctness to go
  86          * anywhere near a pmac i2c bus anyway ...
  87          *
  88          * I'm also not completely sure what kind of phases to do between
  89          * the actual command and the data (what I am _supposed_ to do that
  90          * is). For now, I assume writes are a single stream and reads have
  91          * a repeat start/addr phase (but not stop in between)
  92          */
  93         case I2C_SMBUS_BLOCK_DATA:
  94                 buf = data->block;
  95                 len = data->block[0] + 1;
  96                 break;
  97         case I2C_SMBUS_I2C_BLOCK_DATA:
  98                 buf = &data->block[1];
  99                 len = data->block[0];
 100                 break;
 101
 102         default:
 103                 return -EINVAL;
 104         }
 105
 106         rc = pmac_i2c_open(bus, 0);
 107         if (rc) {
 108                 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
 109                 return rc;
 110         }
 111
 112         rc = pmac_i2c_setmode(bus, mode);
 113         if (rc) {
 114                 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
 115                         mode, rc);
 116                 goto bail;
 117         }
 118
 119         rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len);
 120         if (rc) {
 121                 if (rc == -ENXIO)
 122                         dev_dbg(&adap->dev,
 123                                 "I2C transfer at 0x%02x failed, size %d, "
 124                                 "err %d\n", addrdir >> 1, size, rc);
 125                 else
 126                         dev_err(&adap->dev,
 127                                 "I2C transfer at 0x%02x failed, size %d, "
 128                                 "err %d\n", addrdir >> 1, size, rc);
 129                 goto bail;
 130         }
 131
 132         if (size == I2C_SMBUS_WORD_DATA && read) {
 133                 data->word = ((u16)local[1]) << 8;
 134                 data->word |= local[0];
 135         }
 136
 137  bail:
 138         pmac_i2c_close(bus);
 139         return rc;
 140 }
 141
 142 /*
 143  * Generic i2c master transfer entrypoint. This driver only support single
 144  * messages (for "lame i2c" transfers). Anything else should use the smbus
 145  * entry point
 146  */
 147 static int i2c_powermac_master_xfer(    struct i2c_adapter *adap,
 148                                         struct i2c_msg *msgs,
 149                                         int num)
 150 {
 151         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
 152         int                     rc = 0;
 153         int                     addrdir;
 154
 155         if (msgs->flags & I2C_M_TEN)
 156                 return -EINVAL;
 157         addrdir = i2c_8bit_addr_from_msg(msgs);
 158
 159         rc = pmac_i2c_open(bus, 0);
 160         if (rc) {
 161                 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
 162                 return rc;
 163         }
 164         rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
 165         if (rc) {
 166                 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
 167                         pmac_i2c_mode_std, rc);
 168                 goto bail;
 169         }
 170         rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
 171         if (rc < 0) {
 172                 if (rc == -ENXIO)
 173                         dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
 174                                 addrdir & 1 ? "read from" : "write to",
 175                                 addrdir >> 1, rc);
 176                 else
 177                         dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
 178                                 addrdir & 1 ? "read from" : "write to",
 179                                 addrdir >> 1, rc);
 180         }
 181  bail:
 182         pmac_i2c_close(bus);
 183         return rc < 0 ? rc : 1;
 184 }
 185
 186 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
 187 {
 188         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 189                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 190                 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
 191 }
 192
 193 /* For now, we only handle smbus */
 194 static const struct i2c_algorithm i2c_powermac_algorithm = {
 195         .smbus_xfer     = i2c_powermac_smbus_xfer,
 196         .master_xfer    = i2c_powermac_master_xfer,
 197         .functionality  = i2c_powermac_func,
 198 };
 199
 200 static const struct i2c_adapter_quirks i2c_powermac_quirks = {
 201         .max_num_msgs = 1,
 202 };
 203
 204 static int i2c_powermac_remove(struct platform_device *dev)
 205 {
 206         struct i2c_adapter      *adapter = platform_get_drvdata(dev);
 207
 208         i2c_del_adapter(adapter);
 209         memset(adapter, 0, sizeof(*adapter));
 210
 211         return 0;
 212 }
 213
 214 static u32 i2c_powermac_get_addr(struct i2c_adapter *adap,
 215                                            struct pmac_i2c_bus *bus,
 216                                            struct device_node *node)
 217 {
 218         const __be32 *prop;
 219         int len;
 220
 221         /* First check for valid "reg" */
 222         prop = of_get_property(node, "reg", &len);
 223         if (prop && (len >= sizeof(int)))
 224                 return (be32_to_cpup(prop) & 0xff) >> 1;
 225
 226         /* Then check old-style "i2c-address" */
 227         prop = of_get_property(node, "i2c-address", &len);
 228         if (prop && (len >= sizeof(int)))
 229                 return (be32_to_cpup(prop) & 0xff) >> 1;
 230
 231         /* Now handle some devices with missing "reg" properties */
 232         if (!strcmp(node->name, "cereal"))
 233                 return 0x60;
 234         else if (!strcmp(node->name, "deq"))
 235                 return 0x34;
 236
 237         dev_warn(&adap->dev, "No i2c address for %pOF\n", node);
 238
 239         return 0xffffffff;
 240 }
 241
 242 static void i2c_powermac_create_one(struct i2c_adapter *adap,
 243                                               const char *type,
 244                                               u32 addr)
 245 {
 246         struct i2c_board_info info = {};
 247         struct i2c_client *newdev;
 248
 249         strncpy(info.type, type, sizeof(info.type));
 250         info.addr = addr;
 251         newdev = i2c_new_device(adap, &info);
 252         if (!newdev)
 253                 dev_err(&adap->dev,
 254                         "i2c-powermac: Failure to register missing %s\n",
 255                         type);
 256 }
 257
 258 static void i2c_powermac_add_missing(struct i2c_adapter *adap,
 259                                                struct pmac_i2c_bus *bus,
 260                                                bool found_onyx)
 261 {
 262         struct device_node *busnode = pmac_i2c_get_bus_node(bus);
 263         int rc;
 264
 265         /* Check for the onyx audio codec */
 266 #define ONYX_REG_CONTROL                67
 267         if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
 268                 union i2c_smbus_data data;
 269
 270                 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
 271                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
 272                                     &data);
 273                 if (rc >= 0)
 274                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
 275
 276                 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
 277                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
 278                                     &data);
 279                 if (rc >= 0)
 280                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
 281         }
 282 }
 283
 284 static bool i2c_powermac_get_type(struct i2c_adapter *adap,
 285                                             struct device_node *node,
 286                                             u32 addr, char *type, int type_size)
 287 {
 288         char tmp[16];
 289
 290         /* Note: we to _NOT_ want the standard
 291          * i2c drivers to match with any of our powermac stuff
 292          * unless they have been specifically modified to handle
 293          * it on a case by case basis. For example, for thermal
 294          * control, things like lm75 etc... shall match with their
 295          * corresponding windfarm drivers, _NOT_ the generic ones,
 296          * so we force a prefix of AAPL, onto the modalias to
 297          * make that happen
 298          */
 299
 300         /* First try proper modalias */
 301         if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
 302                 snprintf(type, type_size, "MAC,%s", tmp);
 303                 return true;
 304         }
 305
 306         /* Now look for known workarounds */
 307         if (!strcmp(node->name, "deq")) {
 308                 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
 309                 if (addr == 0x34) {
 310                         snprintf(type, type_size, "MAC,tas3001");
 311                         return true;
 312                 } else if (addr == 0x35) {
 313                         snprintf(type, type_size, "MAC,tas3004");
 314                         return true;
 315                 }
 316         }
 317
 318         dev_err(&adap->dev, "i2c-powermac: modalias failure on %pOF\n", node);
 319         return false;
 320 }
 321
 322 static void i2c_powermac_register_devices(struct i2c_adapter *adap,
 323                                                     struct pmac_i2c_bus *bus)
 324 {
 325         struct i2c_client *newdev;
 326         struct device_node *node;
 327         bool found_onyx = 0;
 328
 329         /*
 330          * In some cases we end up with the via-pmu node itself, in this
 331          * case we skip this function completely as the device-tree will
 332          * not contain anything useful.
 333          */
 334         if (!strcmp(adap->dev.of_node->name, "via-pmu"))
 335                 return;
 336
 337         for_each_child_of_node(adap->dev.of_node, node) {
 338                 struct i2c_board_info info = {};
 339                 u32 addr;
 340
 341                 /* Get address & channel */
 342                 addr = i2c_powermac_get_addr(adap, bus, node);
 343                 if (addr == 0xffffffff)
 344                         continue;
 345
 346                 /* Multibus setup, check channel */
 347                 if (!pmac_i2c_match_adapter(node, adap))
 348                         continue;
 349
 350                 dev_dbg(&adap->dev, "i2c-powermac: register %pOF\n", node);
 351
 352                 /*
 353                  * Keep track of some device existence to handle
 354                  * workarounds later.
 355                  */
 356                 if (of_device_is_compatible(node, "pcm3052"))
 357                         found_onyx = true;
 358
 359                 /* Make up a modalias */
 360                 if (!i2c_powermac_get_type(adap, node, addr,
 361                                            info.type, sizeof(info.type))) {
 362                         continue;
 363                 }
 364
 365                 /* Fill out the rest of the info structure */
 366                 info.addr = addr;
 367                 info.irq = irq_of_parse_and_map(node, 0);
 368                 info.of_node = of_node_get(node);
 369
 370                 newdev = i2c_new_device(adap, &info);
 371                 if (!newdev) {
 372                         dev_err(&adap->dev, "i2c-powermac: Failure to register"
 373                                 " %pOF\n", node);
 374                         of_node_put(node);
 375                         /* We do not dispose of the interrupt mapping on
 376                          * purpose. It's not necessary (interrupt cannot be
 377                          * re-used) and somebody else might have grabbed it
 378                          * via direct DT lookup so let's not bother
 379                          */
 380                         continue;
 381                 }
 382         }
 383
 384         /* Additional workarounds */
 385         i2c_powermac_add_missing(adap, bus, found_onyx);
 386 }
 387
 388 static int i2c_powermac_probe(struct platform_device *dev)
 389 {
 390         struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev);
 391         struct device_node *parent = NULL;
 392         struct i2c_adapter *adapter;
 393         const char *basename;
 394         int rc;
 395
 396         if (bus == NULL)
 397                 return -EINVAL;
 398         adapter = pmac_i2c_get_adapter(bus);
 399
 400         /* Ok, now we need to make up a name for the interface that will
 401          * match what we used to do in the past, that is basically the
 402          * controller's parent device node for keywest. PMU didn't have a
 403          * naming convention and SMU has a different one
 404          */
 405         switch(pmac_i2c_get_type(bus)) {
 406         case pmac_i2c_bus_keywest:
 407                 parent = of_get_parent(pmac_i2c_get_controller(bus));
 408                 if (parent == NULL)
 409                         return -EINVAL;
 410                 basename = parent->name;
 411                 break;
 412         case pmac_i2c_bus_pmu:
 413                 basename = "pmu";
 414                 break;
 415         case pmac_i2c_bus_smu:
 416                 /* This is not what we used to do but I'm fixing drivers at
 417                  * the same time as this change
 418                  */
 419                 basename = "smu";
 420                 break;
 421         default:
 422                 return -EINVAL;
 423         }
 424         snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
 425                  pmac_i2c_get_channel(bus));
 426         of_node_put(parent);
 427
 428         platform_set_drvdata(dev, adapter);
 429         adapter->algo = &i2c_powermac_algorithm;
 430         adapter->quirks = &i2c_powermac_quirks;
 431         i2c_set_adapdata(adapter, bus);
 432         adapter->dev.parent = &dev->dev;
 433
 434         /* Clear of_node to skip automatic registration of i2c child nodes */
 435         adapter->dev.of_node = NULL;
 436         rc = i2c_add_adapter(adapter);
 437         if (rc) {
 438                 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
 439                        "failed\n", adapter->name);
 440                 memset(adapter, 0, sizeof(*adapter));
 441                 return rc;
 442         }
 443
 444         printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
 445
 446         /* Use custom child registration due to Apple device-tree funkyness */
 447         adapter->dev.of_node = dev->dev.of_node;
 448         i2c_powermac_register_devices(adapter, bus);
 449
 450         return 0;
 451 }
 452
 453 static struct platform_driver i2c_powermac_driver = {
 454         .probe = i2c_powermac_probe,
 455         .remove = i2c_powermac_remove,
 456         .driver = {
 457                 .name = "i2c-powermac",
 458                 .bus = &platform_bus_type,
 459         },
 460 };
 461
 462 module_platform_driver(i2c_powermac_driver);
 463
 464 MODULE_ALIAS("platform:i2c-powermac");