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"); 469