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/init.h> 28#include <linux/device.h> 29#include <linux/platform_device.h> 30#include <asm/prom.h> 31#include <asm/pmac_low_i2c.h> 32 33MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 34MODULE_DESCRIPTION("I2C driver for Apple PowerMac"); 35MODULE_LICENSE("GPL"); 36 37/* 38 * SMBUS-type transfer entrypoint 39 */ 40static 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 */ 151static 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 198static 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 */ 206static 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 213static int __devexit i2c_powermac_remove(struct platform_device *dev) 214{ 215 struct i2c_adapter *adapter = platform_get_drvdata(dev); 216 int rc; 217 218 rc = i2c_del_adapter(adapter); 219 /* We aren't that prepared to deal with this... */ 220 if (rc) 221 printk(KERN_WARNING 222 "i2c-powermac.c: Failed to remove bus %s !\n", 223 adapter->name); 224 platform_set_drvdata(dev, NULL); 225 memset(adapter, 0, sizeof(*adapter)); 226 227 return 0; 228} 229 230 231static int __devinit i2c_powermac_probe(struct platform_device *dev) 232{ 233 struct pmac_i2c_bus *bus = dev->dev.platform_data; 234 struct device_node *parent = NULL; 235 struct i2c_adapter *adapter; 236 const char *basename; 237 int rc; 238 239 if (bus == NULL) 240 return -EINVAL; 241 adapter = pmac_i2c_get_adapter(bus); 242 243 /* Ok, now we need to make up a name for the interface that will 244 * match what we used to do in the past, that is basically the 245 * controller's parent device node for keywest. PMU didn't have a 246 * naming convention and SMU has a different one 247 */ 248 switch(pmac_i2c_get_type(bus)) { 249 case pmac_i2c_bus_keywest: 250 parent = of_get_parent(pmac_i2c_get_controller(bus)); 251 if (parent == NULL) 252 return -EINVAL; 253 basename = parent->name; 254 break; 255 case pmac_i2c_bus_pmu: 256 basename = "pmu"; 257 break; 258 case pmac_i2c_bus_smu: 259 /* This is not what we used to do but I'm fixing drivers at 260 * the same time as this change 261 */ 262 basename = "smu"; 263 break; 264 default: 265 return -EINVAL; 266 } 267 snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename, 268 pmac_i2c_get_channel(bus)); 269 of_node_put(parent); 270 271 platform_set_drvdata(dev, adapter); 272 adapter->algo = &i2c_powermac_algorithm; 273 i2c_set_adapdata(adapter, bus); 274 adapter->dev.parent = &dev->dev; 275 rc = i2c_add_adapter(adapter); 276 if (rc) { 277 printk(KERN_ERR "i2c-powermac: Adapter %s registration " 278 "failed\n", adapter->name); 279 memset(adapter, 0, sizeof(*adapter)); 280 } 281 282 printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name); 283 284 if (!strncmp(basename, "uni-n", 5)) { 285 struct device_node *np; 286 const u32 *prop; 287 struct i2c_board_info info; 288 289 /* Instantiate I2C motion sensor if present */ 290 np = of_find_node_by_name(NULL, "accelerometer"); 291 if (np && of_device_is_compatible(np, "AAPL,accelerometer_1") && 292 (prop = of_get_property(np, "reg", NULL))) { 293 int i2c_bus; 294 const char *tmp_bus; 295 296 /* look for bus either using "reg" or by path */ 297 tmp_bus = strstr(np->full_name, "/i2c-bus@"); 298 if (tmp_bus) 299 i2c_bus = *(tmp_bus + 9) - '0'; 300 else 301 i2c_bus = ((*prop) >> 8) & 0x0f; 302 303 if (pmac_i2c_get_channel(bus) == i2c_bus) { 304 memset(&info, 0, sizeof(struct i2c_board_info)); 305 info.addr = ((*prop) & 0xff) >> 1; 306 strlcpy(info.type, "ams", I2C_NAME_SIZE); 307 i2c_new_device(adapter, &info); 308 } 309 } 310 } 311 312 return rc; 313} 314 315 316/* work with hotplug and coldplug */ 317MODULE_ALIAS("platform:i2c-powermac"); 318 319static struct platform_driver i2c_powermac_driver = { 320 .probe = i2c_powermac_probe, 321 .remove = __devexit_p(i2c_powermac_remove), 322 .driver = { 323 .name = "i2c-powermac", 324 .bus = &platform_bus_type, 325 }, 326}; 327 328static int __init i2c_powermac_init(void) 329{ 330 platform_driver_register(&i2c_powermac_driver); 331 return 0; 332} 333 334 335static void __exit i2c_powermac_cleanup(void) 336{ 337 platform_driver_unregister(&i2c_powermac_driver); 338} 339 340module_init(i2c_powermac_init); 341module_exit(i2c_powermac_cleanup); 342