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 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 dev_err(&adap->dev, 126 "I2C transfer at 0x%02x failed, size %d, err %d\n", 127 addrdir >> 1, size, rc); 128 goto bail; 129 } 130 131 if (size == I2C_SMBUS_WORD_DATA && read) { 132 data->word = ((u16)local[1]) << 8; 133 data->word |= local[0]; 134 } 135 136 bail: 137 pmac_i2c_close(bus); 138 return rc; 139 } 140 141 /* 142 * Generic i2c master transfer entrypoint. This driver only support single 143 * messages (for "lame i2c" transfers). Anything else should use the smbus 144 * entry point 145 */ 146 static int i2c_powermac_master_xfer( struct i2c_adapter *adap, 147 struct i2c_msg *msgs, 148 int num) 149 { 150 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 151 int rc = 0; 152 int read; 153 int addrdir; 154 155 if (num != 1) { 156 dev_err(&adap->dev, 157 "Multi-message I2C transactions not supported\n"); 158 return -EOPNOTSUPP; 159 } 160 161 if (msgs->flags & I2C_M_TEN) 162 return -EINVAL; 163 read = (msgs->flags & I2C_M_RD) != 0; 164 addrdir = (msgs->addr << 1) | read; 165 166 rc = pmac_i2c_open(bus, 0); 167 if (rc) { 168 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); 169 return rc; 170 } 171 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 172 if (rc) { 173 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", 174 pmac_i2c_mode_std, rc); 175 goto bail; 176 } 177 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len); 178 if (rc < 0) 179 dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n", 180 addrdir & 1 ? "read from" : "write to", addrdir >> 1, 181 rc); 182 bail: 183 pmac_i2c_close(bus); 184 return rc < 0 ? rc : 1; 185 } 186 187 static u32 i2c_powermac_func(struct i2c_adapter * adapter) 188 { 189 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 190 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | 191 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C; 192 } 193 194 /* For now, we only handle smbus */ 195 static const struct i2c_algorithm i2c_powermac_algorithm = { 196 .smbus_xfer = i2c_powermac_smbus_xfer, 197 .master_xfer = i2c_powermac_master_xfer, 198 .functionality = i2c_powermac_func, 199 }; 200 201 202 static int __devexit i2c_powermac_remove(struct platform_device *dev) 203 { 204 struct i2c_adapter *adapter = platform_get_drvdata(dev); 205 int rc; 206 207 rc = i2c_del_adapter(adapter); 208 /* We aren't that prepared to deal with this... */ 209 if (rc) 210 printk(KERN_WARNING 211 "i2c-powermac.c: Failed to remove bus %s !\n", 212 adapter->name); 213 platform_set_drvdata(dev, NULL); 214 memset(adapter, 0, sizeof(*adapter)); 215 216 return 0; 217 } 218 219 220 static int __devinit i2c_powermac_probe(struct platform_device *dev) 221 { 222 struct pmac_i2c_bus *bus = dev->dev.platform_data; 223 struct device_node *parent = NULL; 224 struct i2c_adapter *adapter; 225 const char *basename; 226 int rc; 227 228 if (bus == NULL) 229 return -EINVAL; 230 adapter = pmac_i2c_get_adapter(bus); 231 232 /* Ok, now we need to make up a name for the interface that will 233 * match what we used to do in the past, that is basically the 234 * controller's parent device node for keywest. PMU didn't have a 235 * naming convention and SMU has a different one 236 */ 237 switch(pmac_i2c_get_type(bus)) { 238 case pmac_i2c_bus_keywest: 239 parent = of_get_parent(pmac_i2c_get_controller(bus)); 240 if (parent == NULL) 241 return -EINVAL; 242 basename = parent->name; 243 break; 244 case pmac_i2c_bus_pmu: 245 basename = "pmu"; 246 break; 247 case pmac_i2c_bus_smu: 248 /* This is not what we used to do but I'm fixing drivers at 249 * the same time as this change 250 */ 251 basename = "smu"; 252 break; 253 default: 254 return -EINVAL; 255 } 256 snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename, 257 pmac_i2c_get_channel(bus)); 258 of_node_put(parent); 259 260 platform_set_drvdata(dev, adapter); 261 adapter->algo = &i2c_powermac_algorithm; 262 i2c_set_adapdata(adapter, bus); 263 adapter->dev.parent = &dev->dev; 264 rc = i2c_add_adapter(adapter); 265 if (rc) { 266 printk(KERN_ERR "i2c-powermac: Adapter %s registration " 267 "failed\n", adapter->name); 268 memset(adapter, 0, sizeof(*adapter)); 269 } 270 271 printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name); 272 273 if (!strncmp(basename, "uni-n", 5)) { 274 struct device_node *np; 275 const u32 *prop; 276 struct i2c_board_info info; 277 278 /* Instantiate I2C motion sensor if present */ 279 np = of_find_node_by_name(NULL, "accelerometer"); 280 if (np && of_device_is_compatible(np, "AAPL,accelerometer_1") && 281 (prop = of_get_property(np, "reg", NULL))) { 282 int i2c_bus; 283 const char *tmp_bus; 284 285 /* look for bus either using "reg" or by path */ 286 tmp_bus = strstr(np->full_name, "/i2c-bus@"); 287 if (tmp_bus) 288 i2c_bus = *(tmp_bus + 9) - '0'; 289 else 290 i2c_bus = ((*prop) >> 8) & 0x0f; 291 292 if (pmac_i2c_get_channel(bus) == i2c_bus) { 293 memset(&info, 0, sizeof(struct i2c_board_info)); 294 info.addr = ((*prop) & 0xff) >> 1; 295 strlcpy(info.type, "ams", I2C_NAME_SIZE); 296 i2c_new_device(adapter, &info); 297 } 298 } 299 } 300 301 return rc; 302 } 303 304 305 /* work with hotplug and coldplug */ 306 MODULE_ALIAS("platform:i2c-powermac"); 307 308 static struct platform_driver i2c_powermac_driver = { 309 .probe = i2c_powermac_probe, 310 .remove = __devexit_p(i2c_powermac_remove), 311 .driver = { 312 .name = "i2c-powermac", 313 .bus = &platform_bus_type, 314 }, 315 }; 316 317 static int __init i2c_powermac_init(void) 318 { 319 platform_driver_register(&i2c_powermac_driver); 320 return 0; 321 } 322 323 324 static void __exit i2c_powermac_cleanup(void) 325 { 326 platform_driver_unregister(&i2c_powermac_driver); 327 } 328 329 module_init(i2c_powermac_init); 330 module_exit(i2c_powermac_cleanup); 331