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                     read;
 154         int                     addrdir;
 155
 156         if (num != 1) {
 157                 dev_err(&adap->dev,
 158                         "Multi-message I2C transactions not supported\n");
 159                 return -EOPNOTSUPP;
 160         }
 161
 162         if (msgs->flags & I2C_M_TEN)
 163                 return -EINVAL;
 164         read = (msgs->flags & I2C_M_RD) != 0;
 165         addrdir = (msgs->addr << 1) | read;
 166
 167         rc = pmac_i2c_open(bus, 0);
 168         if (rc) {
 169                 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
 170                 return rc;
 171         }
 172         rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
 173         if (rc) {
 174                 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
 175                         pmac_i2c_mode_std, rc);
 176                 goto bail;
 177         }
 178         rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
 179         if (rc < 0) {
 180                 if (rc == -ENXIO)
 181                         dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
 182                                 addrdir & 1 ? "read from" : "write to",
 183                                 addrdir >> 1, rc);
 184                 else
 185                         dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
 186                                 addrdir & 1 ? "read from" : "write to",
 187                                 addrdir >> 1, rc);
 188         }
 189  bail:
 190         pmac_i2c_close(bus);
 191         return rc < 0 ? rc : 1;
 192 }
 193
 194 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
 195 {
 196         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 197                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 198                 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
 199 }
 200
 201 /* For now, we only handle smbus */
 202 static const struct i2c_algorithm i2c_powermac_algorithm = {
 203         .smbus_xfer     = i2c_powermac_smbus_xfer,
 204         .master_xfer    = i2c_powermac_master_xfer,
 205         .functionality  = i2c_powermac_func,
 206 };
 207
 208
 209 static int i2c_powermac_remove(struct platform_device *dev)
 210 {
 211         struct i2c_adapter      *adapter = platform_get_drvdata(dev);
 212
 213         i2c_del_adapter(adapter);
 214         memset(adapter, 0, sizeof(*adapter));
 215
 216         return 0;
 217 }
 218
 219 static u32 i2c_powermac_get_addr(struct i2c_adapter *adap,
 220                                            struct pmac_i2c_bus *bus,
 221                                            struct device_node *node)
 222 {
 223         const __be32 *prop;
 224         int len;
 225
 226         /* First check for valid "reg" */
 227         prop = of_get_property(node, "reg", &len);
 228         if (prop && (len >= sizeof(int)))
 229                 return (be32_to_cpup(prop) & 0xff) >> 1;
 230
 231         /* Then check old-style "i2c-address" */
 232         prop = of_get_property(node, "i2c-address", &len);
 233         if (prop && (len >= sizeof(int)))
 234                 return (be32_to_cpup(prop) & 0xff) >> 1;
 235
 236         /* Now handle some devices with missing "reg" properties */
 237         if (!strcmp(node->name, "cereal"))
 238                 return 0x60;
 239         else if (!strcmp(node->name, "deq"))
 240                 return 0x34;
 241
 242         dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name);
 243
 244         return 0xffffffff;
 245 }
 246
 247 static void i2c_powermac_create_one(struct i2c_adapter *adap,
 248                                               const char *type,
 249                                               u32 addr)
 250 {
 251         struct i2c_board_info info = {};
 252         struct i2c_client *newdev;
 253
 254         strncpy(info.type, type, sizeof(info.type));
 255         info.addr = addr;
 256         newdev = i2c_new_device(adap, &info);
 257         if (!newdev)
 258                 dev_err(&adap->dev,
 259                         "i2c-powermac: Failure to register missing %s\n",
 260                         type);
 261 }
 262
 263 static void i2c_powermac_add_missing(struct i2c_adapter *adap,
 264                                                struct pmac_i2c_bus *bus,
 265                                                bool found_onyx)
 266 {
 267         struct device_node *busnode = pmac_i2c_get_bus_node(bus);
 268         int rc;
 269
 270         /* Check for the onyx audio codec */
 271 #define ONYX_REG_CONTROL                67
 272         if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
 273                 union i2c_smbus_data data;
 274
 275                 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
 276                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
 277                                     &data);
 278                 if (rc >= 0)
 279                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
 280
 281                 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
 282                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
 283                                     &data);
 284                 if (rc >= 0)
 285                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
 286         }
 287 }
 288
 289 static bool i2c_powermac_get_type(struct i2c_adapter *adap,
 290                                             struct device_node *node,
 291                                             u32 addr, char *type, int type_size)
 292 {
 293         char tmp[16];
 294
 295         /* Note: we to _NOT_ want the standard
 296          * i2c drivers to match with any of our powermac stuff
 297          * unless they have been specifically modified to handle
 298          * it on a case by case basis. For example, for thermal
 299          * control, things like lm75 etc... shall match with their
 300          * corresponding windfarm drivers, _NOT_ the generic ones,
 301          * so we force a prefix of AAPL, onto the modalias to
 302          * make that happen
 303          */
 304
 305         /* First try proper modalias */
 306         if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
 307                 snprintf(type, type_size, "MAC,%s", tmp);
 308                 return true;
 309         }
 310
 311         /* Now look for known workarounds */
 312         if (!strcmp(node->name, "deq")) {
 313                 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
 314                 if (addr == 0x34) {
 315                         snprintf(type, type_size, "MAC,tas3001");
 316                         return true;
 317                 } else if (addr == 0x35) {
 318                         snprintf(type, type_size, "MAC,tas3004");
 319                         return true;
 320                 }
 321         }
 322
 323         dev_err(&adap->dev, "i2c-powermac: modalias failure"
 324                 " on %s\n", node->full_name);
 325         return false;
 326 }
 327
 328 static void i2c_powermac_register_devices(struct i2c_adapter *adap,
 329                                                     struct pmac_i2c_bus *bus)
 330 {
 331         struct i2c_client *newdev;
 332         struct device_node *node;
 333         bool found_onyx = 0;
 334
 335         /*
 336          * In some cases we end up with the via-pmu node itself, in this
 337          * case we skip this function completely as the device-tree will
 338          * not contain anything useful.
 339          */
 340         if (!strcmp(adap->dev.of_node->name, "via-pmu"))
 341                 return;
 342
 343         for_each_child_of_node(adap->dev.of_node, node) {
 344                 struct i2c_board_info info = {};
 345                 u32 addr;
 346
 347                 /* Get address & channel */
 348                 addr = i2c_powermac_get_addr(adap, bus, node);
 349                 if (addr == 0xffffffff)
 350                         continue;
 351
 352                 /* Multibus setup, check channel */
 353                 if (!pmac_i2c_match_adapter(node, adap))
 354                         continue;
 355
 356                 dev_dbg(&adap->dev, "i2c-powermac: register %s\n",
 357                         node->full_name);
 358
 359                 /*
 360                  * Keep track of some device existence to handle
 361                  * workarounds later.
 362                  */
 363                 if (of_device_is_compatible(node, "pcm3052"))
 364                         found_onyx = true;
 365
 366                 /* Make up a modalias */
 367                 if (!i2c_powermac_get_type(adap, node, addr,
 368                                            info.type, sizeof(info.type))) {
 369                         continue;
 370                 }
 371
 372                 /* Fill out the rest of the info structure */
 373                 info.addr = addr;
 374                 info.irq = irq_of_parse_and_map(node, 0);
 375                 info.of_node = of_node_get(node);
 376
 377                 newdev = i2c_new_device(adap, &info);
 378                 if (!newdev) {
 379                         dev_err(&adap->dev, "i2c-powermac: Failure to register"
 380                                 " %s\n", node->full_name);
 381                         of_node_put(node);
 382                         /* We do not dispose of the interrupt mapping on
 383                          * purpose. It's not necessary (interrupt cannot be
 384                          * re-used) and somebody else might have grabbed it
 385                          * via direct DT lookup so let's not bother
 386                          */
 387                         continue;
 388                 }
 389         }
 390
 391         /* Additional workarounds */
 392         i2c_powermac_add_missing(adap, bus, found_onyx);
 393 }
 394
 395 static int i2c_powermac_probe(struct platform_device *dev)
 396 {
 397         struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev);
 398         struct device_node *parent = NULL;
 399         struct i2c_adapter *adapter;
 400         const char *basename;
 401         int rc;
 402
 403         if (bus == NULL)
 404                 return -EINVAL;
 405         adapter = pmac_i2c_get_adapter(bus);
 406
 407         /* Ok, now we need to make up a name for the interface that will
 408          * match what we used to do in the past, that is basically the
 409          * controller's parent device node for keywest. PMU didn't have a
 410          * naming convention and SMU has a different one
 411          */
 412         switch(pmac_i2c_get_type(bus)) {
 413         case pmac_i2c_bus_keywest:
 414                 parent = of_get_parent(pmac_i2c_get_controller(bus));
 415                 if (parent == NULL)
 416                         return -EINVAL;
 417                 basename = parent->name;
 418                 break;
 419         case pmac_i2c_bus_pmu:
 420                 basename = "pmu";
 421                 break;
 422         case pmac_i2c_bus_smu:
 423                 /* This is not what we used to do but I'm fixing drivers at
 424                  * the same time as this change
 425                  */
 426                 basename = "smu";
 427                 break;
 428         default:
 429                 return -EINVAL;
 430         }
 431         snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
 432                  pmac_i2c_get_channel(bus));
 433         of_node_put(parent);
 434
 435         platform_set_drvdata(dev, adapter);
 436         adapter->algo = &i2c_powermac_algorithm;
 437         i2c_set_adapdata(adapter, bus);
 438         adapter->dev.parent = &dev->dev;
 439
 440         /* Clear of_node to skip automatic registration of i2c child nodes */
 441         adapter->dev.of_node = NULL;
 442         rc = i2c_add_adapter(adapter);
 443         if (rc) {
 444                 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
 445                        "failed\n", adapter->name);
 446                 memset(adapter, 0, sizeof(*adapter));
 447                 return rc;
 448         }
 449
 450         printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
 451
 452         /* Use custom child registration due to Apple device-tree funkyness */
 453         adapter->dev.of_node = dev->dev.of_node;
 454         i2c_powermac_register_devices(adapter, bus);
 455
 456         return 0;
 457 }
 458
 459 static struct platform_driver i2c_powermac_driver = {
 460         .probe = i2c_powermac_probe,
 461         .remove = i2c_powermac_remove,
 462         .driver = {
 463                 .name = "i2c-powermac",
 464                 .bus = &platform_bus_type,
 465         },
 466 };
 467
 468 module_platform_driver(i2c_powermac_driver);
 469
 470 MODULE_ALIAS("platform:i2c-powermac");