kernel/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 (msgs->flags & I2C_M_TEN)
 157                 return -EINVAL;
 158         read = (msgs->flags & I2C_M_RD) != 0;
 159         addrdir = (msgs->addr << 1) | read;
 160
 161         rc = pmac_i2c_open(bus, 0);
 162         if (rc) {
 163                 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
 164                 return rc;
 165         }
 166         rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
 167         if (rc) {
 168                 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
 169                         pmac_i2c_mode_std, rc);
 170                 goto bail;
 171         }
 172         rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
 173         if (rc < 0) {
 174                 if (rc == -ENXIO)
 175                         dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
 176                                 addrdir & 1 ? "read from" : "write to",
 177                                 addrdir >> 1, rc);
 178                 else
 179                         dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
 180                                 addrdir & 1 ? "read from" : "write to",
 181                                 addrdir >> 1, rc);
 182         }
 183  bail:
 184         pmac_i2c_close(bus);
 185         return rc < 0 ? rc : 1;
 186 }
 187
 188 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
 189 {
 190         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 191                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 192                 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
 193 }
 194
 195 /* For now, we only handle smbus */
 196 static const struct i2c_algorithm i2c_powermac_algorithm = {
 197         .smbus_xfer     = i2c_powermac_smbus_xfer,
 198         .master_xfer    = i2c_powermac_master_xfer,
 199         .functionality  = i2c_powermac_func,
 200 };
 201
 202 static struct i2c_adapter_quirks i2c_powermac_quirks = {
 203         .max_num_msgs = 1,
 204 };
 205
 206 static int i2c_powermac_remove(struct platform_device *dev)
 207 {
 208         struct i2c_adapter      *adapter = platform_get_drvdata(dev);
 209
 210         i2c_del_adapter(adapter);
 211         memset(adapter, 0, sizeof(*adapter));
 212
 213         return 0;
 214 }
 215
 216 static u32 i2c_powermac_get_addr(struct i2c_adapter *adap,
 217                                            struct pmac_i2c_bus *bus,
 218                                            struct device_node *node)
 219 {
 220         const __be32 *prop;
 221         int len;
 222
 223         /* First check for valid "reg" */
 224         prop = of_get_property(node, "reg", &len);
 225         if (prop && (len >= sizeof(int)))
 226                 return (be32_to_cpup(prop) & 0xff) >> 1;
 227
 228         /* Then check old-style "i2c-address" */
 229         prop = of_get_property(node, "i2c-address", &len);
 230         if (prop && (len >= sizeof(int)))
 231                 return (be32_to_cpup(prop) & 0xff) >> 1;
 232
 233         /* Now handle some devices with missing "reg" properties */
 234         if (!strcmp(node->name, "cereal"))
 235                 return 0x60;
 236         else if (!strcmp(node->name, "deq"))
 237                 return 0x34;
 238
 239         dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name);
 240
 241         return 0xffffffff;
 242 }
 243
 244 static void i2c_powermac_create_one(struct i2c_adapter *adap,
 245                                               const char *type,
 246                                               u32 addr)
 247 {
 248         struct i2c_board_info info = {};
 249         struct i2c_client *newdev;
 250
 251         strncpy(info.type, type, sizeof(info.type));
 252         info.addr = addr;
 253         newdev = i2c_new_device(adap, &info);
 254         if (!newdev)
 255                 dev_err(&adap->dev,
 256                         "i2c-powermac: Failure to register missing %s\n",
 257                         type);
 258 }
 259
 260 static void i2c_powermac_add_missing(struct i2c_adapter *adap,
 261                                                struct pmac_i2c_bus *bus,
 262                                                bool found_onyx)
 263 {
 264         struct device_node *busnode = pmac_i2c_get_bus_node(bus);
 265         int rc;
 266
 267         /* Check for the onyx audio codec */
 268 #define ONYX_REG_CONTROL                67
 269         if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
 270                 union i2c_smbus_data data;
 271
 272                 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
 273                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
 274                                     &data);
 275                 if (rc >= 0)
 276                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
 277
 278                 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
 279                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
 280                                     &data);
 281                 if (rc >= 0)
 282                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
 283         }
 284 }
 285
 286 static bool i2c_powermac_get_type(struct i2c_adapter *adap,
 287                                             struct device_node *node,
 288                                             u32 addr, char *type, int type_size)
 289 {
 290         char tmp[16];
 291
 292         /* Note: we to _NOT_ want the standard
 293          * i2c drivers to match with any of our powermac stuff
 294          * unless they have been specifically modified to handle
 295          * it on a case by case basis. For example, for thermal
 296          * control, things like lm75 etc... shall match with their
 297          * corresponding windfarm drivers, _NOT_ the generic ones,
 298          * so we force a prefix of AAPL, onto the modalias to
 299          * make that happen
 300          */
 301
 302         /* First try proper modalias */
 303         if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
 304                 snprintf(type, type_size, "MAC,%s", tmp);
 305                 return true;
 306         }
 307
 308         /* Now look for known workarounds */
 309         if (!strcmp(node->name, "deq")) {
 310                 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
 311                 if (addr == 0x34) {
 312                         snprintf(type, type_size, "MAC,tas3001");
 313                         return true;
 314                 } else if (addr == 0x35) {
 315                         snprintf(type, type_size, "MAC,tas3004");
 316                         return true;
 317                 }
 318         }
 319
 320         dev_err(&adap->dev, "i2c-powermac: modalias failure"
 321                 " on %s\n", node->full_name);
 322         return false;
 323 }
 324
 325 static void i2c_powermac_register_devices(struct i2c_adapter *adap,
 326                                                     struct pmac_i2c_bus *bus)
 327 {
 328         struct i2c_client *newdev;
 329         struct device_node *node;
 330         bool found_onyx = 0;
 331
 332         /*
 333          * In some cases we end up with the via-pmu node itself, in this
 334          * case we skip this function completely as the device-tree will
 335          * not contain anything useful.
 336          */
 337         if (!strcmp(adap->dev.of_node->name, "via-pmu"))
 338                 return;
 339
 340         for_each_child_of_node(adap->dev.of_node, node) {
 341                 struct i2c_board_info info = {};
 342                 u32 addr;
 343
 344                 /* Get address & channel */
 345                 addr = i2c_powermac_get_addr(adap, bus, node);
 346                 if (addr == 0xffffffff)
 347                         continue;
 348
 349                 /* Multibus setup, check channel */
 350                 if (!pmac_i2c_match_adapter(node, adap))
 351                         continue;
 352
 353                 dev_dbg(&adap->dev, "i2c-powermac: register %s\n",
 354                         node->full_name);
 355
 356                 /*
 357                  * Keep track of some device existence to handle
 358                  * workarounds later.
 359                  */
 360                 if (of_device_is_compatible(node, "pcm3052"))
 361                         found_onyx = true;
 362
 363                 /* Make up a modalias */
 364                 if (!i2c_powermac_get_type(adap, node, addr,
 365                                            info.type, sizeof(info.type))) {
 366                         continue;
 367                 }
 368
 369                 /* Fill out the rest of the info structure */
 370                 info.addr = addr;
 371                 info.irq = irq_of_parse_and_map(node, 0);
 372                 info.of_node = of_node_get(node);
 373
 374                 newdev = i2c_new_device(adap, &info);
 375                 if (!newdev) {
 376                         dev_err(&adap->dev, "i2c-powermac: Failure to register"
 377                                 " %s\n", node->full_name);
 378                         of_node_put(node);
 379                         /* We do not dispose of the interrupt mapping on
 380                          * purpose. It's not necessary (interrupt cannot be
 381                          * re-used) and somebody else might have grabbed it
 382                          * via direct DT lookup so let's not bother
 383                          */
 384                         continue;
 385                 }
 386         }
 387
 388         /* Additional workarounds */
 389         i2c_powermac_add_missing(adap, bus, found_onyx);
 390 }
 391
 392 static int i2c_powermac_probe(struct platform_device *dev)
 393 {
 394         struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev);
 395         struct device_node *parent = NULL;
 396         struct i2c_adapter *adapter;
 397         const char *basename;
 398         int rc;
 399
 400         if (bus == NULL)
 401                 return -EINVAL;
 402         adapter = pmac_i2c_get_adapter(bus);
 403
 404         /* Ok, now we need to make up a name for the interface that will
 405          * match what we used to do in the past, that is basically the
 406          * controller's parent device node for keywest. PMU didn't have a
 407          * naming convention and SMU has a different one
 408          */
 409         switch(pmac_i2c_get_type(bus)) {
 410         case pmac_i2c_bus_keywest:
 411                 parent = of_get_parent(pmac_i2c_get_controller(bus));
 412                 if (parent == NULL)
 413                         return -EINVAL;
 414                 basename = parent->name;
 415                 break;
 416         case pmac_i2c_bus_pmu:
 417                 basename = "pmu";
 418                 break;
 419         case pmac_i2c_bus_smu:
 420                 /* This is not what we used to do but I'm fixing drivers at
 421                  * the same time as this change
 422                  */
 423                 basename = "smu";
 424                 break;
 425         default:
 426                 return -EINVAL;
 427         }
 428         snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
 429                  pmac_i2c_get_channel(bus));
 430         of_node_put(parent);
 431
 432         platform_set_drvdata(dev, adapter);
 433         adapter->algo = &i2c_powermac_algorithm;
 434         adapter->quirks = &i2c_powermac_quirks;
 435         i2c_set_adapdata(adapter, bus);
 436         adapter->dev.parent = &dev->dev;
 437
 438         /* Clear of_node to skip automatic registration of i2c child nodes */
 439         adapter->dev.of_node = NULL;
 440         rc = i2c_add_adapter(adapter);
 441         if (rc) {
 442                 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
 443                        "failed\n", adapter->name);
 444                 memset(adapter, 0, sizeof(*adapter));
 445                 return rc;
 446         }
 447
 448         printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
 449
 450         /* Use custom child registration due to Apple device-tree funkyness */
 451         adapter->dev.of_node = dev->dev.of_node;
 452         i2c_powermac_register_devices(adapter, bus);
 453
 454         return 0;
 455 }
 456
 457 static struct platform_driver i2c_powermac_driver = {
 458         .probe = i2c_powermac_probe,
 459         .remove = i2c_powermac_remove,
 460         .driver = {
 461                 .name = "i2c-powermac",
 462                 .bus = &platform_bus_type,
 463         },
 464 };
 465
 466 module_platform_driver(i2c_powermac_driver);
 467
 468 MODULE_ALIAS("platform:i2c-powermac");