1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 i2c Support for Apple SMU Controller 4 5 Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp. 6 <benh@kernel.crashing.org> 7 8 9 */ 10 11 #include <linux/module.h> 12 #include <linux/kernel.h> 13 #include <linux/types.h> 14 #include <linux/i2c.h> 15 #include <linux/device.h> 16 #include <linux/platform_device.h> 17 #include <linux/of_irq.h> 18 19 #include <asm/pmac_low_i2c.h> 20 21 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 22 MODULE_DESCRIPTION("I2C driver for Apple PowerMac"); 23 MODULE_LICENSE("GPL"); 24 25 /* 26 * SMBUS-type transfer entrypoint 27 */ 28 static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap, 29 u16 addr, 30 unsigned short flags, 31 char read_write, 32 u8 command, 33 int size, 34 union i2c_smbus_data* data) 35 { 36 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 37 int rc = 0; 38 int read = (read_write == I2C_SMBUS_READ); 39 int addrdir = (addr << 1) | read; 40 int mode, subsize, len; 41 u32 subaddr; 42 u8 *buf; 43 u8 local[2]; 44 45 if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) { 46 mode = pmac_i2c_mode_std; 47 subsize = 0; 48 subaddr = 0; 49 } else { 50 mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub; 51 subsize = 1; 52 subaddr = command; 53 } 54 55 switch (size) { 56 case I2C_SMBUS_QUICK: 57 buf = NULL; 58 len = 0; 59 break; 60 case I2C_SMBUS_BYTE: 61 case I2C_SMBUS_BYTE_DATA: 62 buf = &data->byte; 63 len = 1; 64 break; 65 case I2C_SMBUS_WORD_DATA: 66 if (!read) { 67 local[0] = data->word & 0xff; 68 local[1] = (data->word >> 8) & 0xff; 69 } 70 buf = local; 71 len = 2; 72 break; 73 74 /* Note that these are broken vs. the expected smbus API where 75 * on reads, the length is actually returned from the function, 76 * but I think the current API makes no sense and I don't want 77 * any driver that I haven't verified for correctness to go 78 * anywhere near a pmac i2c bus anyway ... 79 */ 80 case I2C_SMBUS_BLOCK_DATA: 81 buf = data->block; 82 len = data->block[0] + 1; 83 break; 84 case I2C_SMBUS_I2C_BLOCK_DATA: 85 buf = &data->block[1]; 86 len = data->block[0]; 87 break; 88 89 default: 90 return -EINVAL; 91 } 92 93 rc = pmac_i2c_open(bus, 0); 94 if (rc) { 95 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); 96 return rc; 97 } 98 99 rc = pmac_i2c_setmode(bus, mode); 100 if (rc) { 101 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", 102 mode, rc); 103 goto bail; 104 } 105 106 rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len); 107 if (rc) { 108 if (rc == -ENXIO) 109 dev_dbg(&adap->dev, 110 "I2C transfer at 0x%02x failed, size %d, " 111 "err %d\n", addrdir >> 1, size, rc); 112 else 113 dev_err(&adap->dev, 114 "I2C transfer at 0x%02x failed, size %d, " 115 "err %d\n", addrdir >> 1, size, rc); 116 goto bail; 117 } 118 119 if (size == I2C_SMBUS_WORD_DATA && read) { 120 data->word = ((u16)local[1]) << 8; 121 data->word |= local[0]; 122 } 123 124 bail: 125 pmac_i2c_close(bus); 126 return rc; 127 } 128 129 /* 130 * Generic i2c transfer entrypoint. This driver only supports single 131 * messages (for "lame i2c" transfers). Anything else should use the smbus 132 * entry point 133 */ 134 static int i2c_powermac_xfer(struct i2c_adapter *adap, 135 struct i2c_msg *msgs, 136 int num) 137 { 138 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 139 int rc = 0; 140 int addrdir; 141 142 if (msgs->flags & I2C_M_TEN) 143 return -EINVAL; 144 addrdir = i2c_8bit_addr_from_msg(msgs); 145 146 rc = pmac_i2c_open(bus, 0); 147 if (rc) { 148 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); 149 return rc; 150 } 151 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 152 if (rc) { 153 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", 154 pmac_i2c_mode_std, rc); 155 goto bail; 156 } 157 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len); 158 if (rc < 0) { 159 if (rc == -ENXIO) 160 dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n", 161 addrdir & 1 ? "read from" : "write to", 162 addrdir >> 1, rc); 163 else 164 dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n", 165 addrdir & 1 ? "read from" : "write to", 166 addrdir >> 1, rc); 167 } 168 bail: 169 pmac_i2c_close(bus); 170 return rc < 0 ? rc : 1; 171 } 172 173 static u32 i2c_powermac_func(struct i2c_adapter * adapter) 174 { 175 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 176 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | 177 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C; 178 } 179 180 /* For now, we only handle smbus */ 181 static const struct i2c_algorithm i2c_powermac_algorithm = { 182 .smbus_xfer = i2c_powermac_smbus_xfer, 183 .xfer = i2c_powermac_xfer, 184 .functionality = i2c_powermac_func, 185 }; 186 187 static const struct i2c_adapter_quirks i2c_powermac_quirks = { 188 .max_num_msgs = 1, 189 }; 190 191 static void i2c_powermac_remove(struct platform_device *dev) 192 { 193 struct i2c_adapter *adapter = platform_get_drvdata(dev); 194 195 i2c_del_adapter(adapter); 196 memset(adapter, 0, sizeof(*adapter)); 197 } 198 199 static u32 i2c_powermac_get_addr(struct i2c_adapter *adap, 200 struct pmac_i2c_bus *bus, 201 struct device_node *node) 202 { 203 u32 prop; 204 int ret; 205 206 /* First check for valid "reg" */ 207 ret = of_property_read_u32(node, "reg", &prop); 208 if (ret == 0) 209 return (prop & 0xff) >> 1; 210 211 /* Then check old-style "i2c-address" */ 212 ret = of_property_read_u32(node, "i2c-address", &prop); 213 if (ret == 0) 214 return (prop & 0xff) >> 1; 215 216 /* Now handle some devices with missing "reg" properties */ 217 if (of_node_name_eq(node, "cereal")) 218 return 0x60; 219 else if (of_node_name_eq(node, "deq")) 220 return 0x34; 221 222 dev_warn(&adap->dev, "No i2c address for %pOF\n", node); 223 224 return 0xffffffff; 225 } 226 227 static void i2c_powermac_create_one(struct i2c_adapter *adap, 228 const char *type, 229 u32 addr) 230 { 231 struct i2c_board_info info = {}; 232 struct i2c_client *newdev; 233 234 strscpy(info.type, type, sizeof(info.type)); 235 info.addr = addr; 236 newdev = i2c_new_client_device(adap, &info); 237 if (IS_ERR(newdev)) 238 dev_err(&adap->dev, 239 "i2c-powermac: Failure to register missing %s\n", 240 type); 241 } 242 243 static void i2c_powermac_add_missing(struct i2c_adapter *adap, 244 struct pmac_i2c_bus *bus, 245 bool found_onyx) 246 { 247 struct device_node *busnode = pmac_i2c_get_bus_node(bus); 248 int rc; 249 250 /* Check for the onyx audio codec */ 251 #define ONYX_REG_CONTROL 67 252 if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) { 253 union i2c_smbus_data data; 254 255 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ, 256 ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA, 257 &data); 258 if (rc >= 0) 259 i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46); 260 261 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ, 262 ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA, 263 &data); 264 if (rc >= 0) 265 i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47); 266 } 267 } 268 269 static bool i2c_powermac_get_type(struct i2c_adapter *adap, 270 struct device_node *node, 271 u32 addr, char *type, int type_size) 272 { 273 char tmp[16]; 274 275 /* 276 * Note: we do _NOT_ want the standard i2c drivers to match with any of 277 * our powermac stuff unless they have been specifically modified to 278 * handle it on a case by case basis. For example, for thermal control, 279 * things like lm75 etc... shall match with their corresponding 280 * windfarm drivers, _NOT_ the generic ones, so we force a prefix of 281 * 'MAC', onto the modalias to make that happen 282 */ 283 284 /* First try proper modalias */ 285 if (of_alias_from_compatible(node, tmp, sizeof(tmp)) >= 0) { 286 snprintf(type, type_size, "MAC,%s", tmp); 287 return true; 288 } 289 290 /* Now look for known workarounds */ 291 if (of_node_name_eq(node, "deq")) { 292 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */ 293 if (addr == 0x34) { 294 snprintf(type, type_size, "MAC,tas3001"); 295 return true; 296 } else if (addr == 0x35) { 297 snprintf(type, type_size, "MAC,tas3004"); 298 return true; 299 } 300 } 301 302 dev_err(&adap->dev, "i2c-powermac: modalias failure on %pOF\n", node); 303 return false; 304 } 305 306 static void i2c_powermac_register_devices(struct i2c_adapter *adap, 307 struct pmac_i2c_bus *bus) 308 { 309 struct i2c_client *newdev; 310 struct device_node *node; 311 bool found_onyx = false; 312 313 /* 314 * In some cases we end up with the via-pmu node itself, in this 315 * case we skip this function completely as the device-tree will 316 * not contain anything useful. 317 */ 318 if (of_node_name_eq(adap->dev.of_node, "via-pmu")) 319 return; 320 321 for_each_child_of_node(adap->dev.of_node, node) { 322 struct i2c_board_info info = {}; 323 u32 addr; 324 325 /* Get address & channel */ 326 addr = i2c_powermac_get_addr(adap, bus, node); 327 if (addr == 0xffffffff) 328 continue; 329 330 /* Multibus setup, check channel */ 331 if (!pmac_i2c_match_adapter(node, adap)) 332 continue; 333 334 dev_dbg(&adap->dev, "i2c-powermac: register %pOF\n", node); 335 336 /* 337 * Keep track of some device existence to handle 338 * workarounds later. 339 */ 340 if (of_device_is_compatible(node, "pcm3052")) 341 found_onyx = true; 342 343 /* Make up a modalias */ 344 if (!i2c_powermac_get_type(adap, node, addr, 345 info.type, sizeof(info.type))) { 346 continue; 347 } 348 349 /* Fill out the rest of the info structure */ 350 info.addr = addr; 351 info.irq = irq_of_parse_and_map(node, 0); 352 info.of_node = of_node_get(node); 353 354 newdev = i2c_new_client_device(adap, &info); 355 if (IS_ERR(newdev)) { 356 dev_err(&adap->dev, "i2c-powermac: Failure to register" 357 " %pOF\n", node); 358 of_node_put(node); 359 /* We do not dispose of the interrupt mapping on 360 * purpose. It's not necessary (interrupt cannot be 361 * re-used) and somebody else might have grabbed it 362 * via direct DT lookup so let's not bother 363 */ 364 continue; 365 } 366 } 367 368 /* Additional workarounds */ 369 i2c_powermac_add_missing(adap, bus, found_onyx); 370 } 371 372 static int i2c_powermac_probe(struct platform_device *dev) 373 { 374 struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev); 375 struct device_node *parent; 376 struct i2c_adapter *adapter; 377 int rc; 378 379 if (bus == NULL) 380 return -EINVAL; 381 adapter = pmac_i2c_get_adapter(bus); 382 383 /* Ok, now we need to make up a name for the interface that will 384 * match what we used to do in the past, that is basically the 385 * controller's parent device node for keywest. PMU didn't have a 386 * naming convention and SMU has a different one 387 */ 388 switch(pmac_i2c_get_type(bus)) { 389 case pmac_i2c_bus_keywest: 390 parent = of_get_parent(pmac_i2c_get_controller(bus)); 391 if (parent == NULL) 392 return -EINVAL; 393 snprintf(adapter->name, sizeof(adapter->name), "%pOFn %d", 394 parent, 395 pmac_i2c_get_channel(bus)); 396 of_node_put(parent); 397 break; 398 case pmac_i2c_bus_pmu: 399 snprintf(adapter->name, sizeof(adapter->name), "pmu %d", 400 pmac_i2c_get_channel(bus)); 401 break; 402 case pmac_i2c_bus_smu: 403 /* This is not what we used to do but I'm fixing drivers at 404 * the same time as this change 405 */ 406 snprintf(adapter->name, sizeof(adapter->name), "smu %d", 407 pmac_i2c_get_channel(bus)); 408 break; 409 default: 410 return -EINVAL; 411 } 412 413 platform_set_drvdata(dev, adapter); 414 adapter->algo = &i2c_powermac_algorithm; 415 adapter->quirks = &i2c_powermac_quirks; 416 i2c_set_adapdata(adapter, bus); 417 adapter->dev.parent = &dev->dev; 418 419 /* Clear of_node to skip automatic registration of i2c child nodes */ 420 adapter->dev.of_node = NULL; 421 rc = i2c_add_adapter(adapter); 422 if (rc) { 423 printk(KERN_ERR "i2c-powermac: Adapter %s registration " 424 "failed\n", adapter->name); 425 memset(adapter, 0, sizeof(*adapter)); 426 return rc; 427 } 428 429 printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name); 430 431 /* Use custom child registration due to Apple device-tree funkyness */ 432 adapter->dev.of_node = dev->dev.of_node; 433 i2c_powermac_register_devices(adapter, bus); 434 435 return 0; 436 } 437 438 static struct platform_driver i2c_powermac_driver = { 439 .probe = i2c_powermac_probe, 440 .remove_new = i2c_powermac_remove, 441 .driver = { 442 .name = "i2c-powermac", 443 .bus = &platform_bus_type, 444 }, 445 }; 446 447 module_platform_driver(i2c_powermac_driver); 448 449 MODULE_ALIAS("platform:i2c-powermac"); 450