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