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"); 475