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 u8 local[2]; 53 54 rc = pmac_i2c_open(bus, 0); 55 if (rc) 56 return rc; 57 58 switch (size) { 59 case I2C_SMBUS_QUICK: 60 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 61 if (rc) 62 goto bail; 63 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, NULL, 0); 64 break; 65 case I2C_SMBUS_BYTE: 66 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 67 if (rc) 68 goto bail; 69 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, &data->byte, 1); 70 break; 71 case I2C_SMBUS_BYTE_DATA: 72 rc = pmac_i2c_setmode(bus, read ? 73 pmac_i2c_mode_combined : 74 pmac_i2c_mode_stdsub); 75 if (rc) 76 goto bail; 77 rc = pmac_i2c_xfer(bus, addrdir, 1, command, &data->byte, 1); 78 break; 79 case I2C_SMBUS_WORD_DATA: 80 rc = pmac_i2c_setmode(bus, read ? 81 pmac_i2c_mode_combined : 82 pmac_i2c_mode_stdsub); 83 if (rc) 84 goto bail; 85 if (!read) { 86 local[0] = data->word & 0xff; 87 local[1] = (data->word >> 8) & 0xff; 88 } 89 rc = pmac_i2c_xfer(bus, addrdir, 1, command, local, 2); 90 if (rc == 0 && read) { 91 data->word = ((u16)local[1]) << 8; 92 data->word |= local[0]; 93 } 94 break; 95 96 /* Note that these are broken vs. the expected smbus API where 97 * on reads, the length is actually returned from the function, 98 * but I think the current API makes no sense and I don't want 99 * any driver that I haven't verified for correctness to go 100 * anywhere near a pmac i2c bus anyway ... 101 * 102 * I'm also not completely sure what kind of phases to do between 103 * the actual command and the data (what I am _supposed_ to do that 104 * is). For now, I assume writes are a single stream and reads have 105 * a repeat start/addr phase (but not stop in between) 106 */ 107 case I2C_SMBUS_BLOCK_DATA: 108 rc = pmac_i2c_setmode(bus, read ? 109 pmac_i2c_mode_combined : 110 pmac_i2c_mode_stdsub); 111 if (rc) 112 goto bail; 113 rc = pmac_i2c_xfer(bus, addrdir, 1, command, data->block, 114 data->block[0] + 1); 115 116 break; 117 case I2C_SMBUS_I2C_BLOCK_DATA: 118 rc = pmac_i2c_setmode(bus, read ? 119 pmac_i2c_mode_combined : 120 pmac_i2c_mode_stdsub); 121 if (rc) 122 goto bail; 123 rc = pmac_i2c_xfer(bus, addrdir, 1, command, 124 &data->block[1], data->block[0]); 125 break; 126 127 default: 128 rc = -EINVAL; 129 } 130 bail: 131 pmac_i2c_close(bus); 132 return rc; 133 } 134 135 /* 136 * Generic i2c master transfer entrypoint. This driver only support single 137 * messages (for "lame i2c" transfers). Anything else should use the smbus 138 * entry point 139 */ 140 static int i2c_powermac_master_xfer( struct i2c_adapter *adap, 141 struct i2c_msg *msgs, 142 int num) 143 { 144 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 145 int rc = 0; 146 int read; 147 int addrdir; 148 149 if (msgs->flags & I2C_M_TEN) 150 return -EINVAL; 151 read = (msgs->flags & I2C_M_RD) != 0; 152 addrdir = (msgs->addr << 1) | read; 153 if (msgs->flags & I2C_M_REV_DIR_ADDR) 154 addrdir ^= 1; 155 156 rc = pmac_i2c_open(bus, 0); 157 if (rc) 158 return rc; 159 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 160 if (rc) 161 goto bail; 162 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len); 163 bail: 164 pmac_i2c_close(bus); 165 return rc < 0 ? rc : 1; 166 } 167 168 static u32 i2c_powermac_func(struct i2c_adapter * adapter) 169 { 170 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 171 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | 172 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C; 173 } 174 175 /* For now, we only handle smbus */ 176 static const struct i2c_algorithm i2c_powermac_algorithm = { 177 .smbus_xfer = i2c_powermac_smbus_xfer, 178 .master_xfer = i2c_powermac_master_xfer, 179 .functionality = i2c_powermac_func, 180 }; 181 182 183 static int __devexit i2c_powermac_remove(struct platform_device *dev) 184 { 185 struct i2c_adapter *adapter = platform_get_drvdata(dev); 186 struct pmac_i2c_bus *bus = i2c_get_adapdata(adapter); 187 int rc; 188 189 rc = i2c_del_adapter(adapter); 190 pmac_i2c_detach_adapter(bus, adapter); 191 i2c_set_adapdata(adapter, NULL); 192 /* We aren't that prepared to deal with this... */ 193 if (rc) 194 printk("i2c-powermac.c: Failed to remove bus %s !\n", 195 adapter->name); 196 platform_set_drvdata(dev, NULL); 197 kfree(adapter); 198 199 return 0; 200 } 201 202 203 static int __devinit i2c_powermac_probe(struct platform_device *dev) 204 { 205 struct pmac_i2c_bus *bus = dev->dev.platform_data; 206 struct device_node *parent = NULL; 207 struct i2c_adapter *adapter; 208 char name[32]; 209 const char *basename; 210 int rc; 211 212 if (bus == NULL) 213 return -EINVAL; 214 215 /* Ok, now we need to make up a name for the interface that will 216 * match what we used to do in the past, that is basically the 217 * controller's parent device node for keywest. PMU didn't have a 218 * naming convention and SMU has a different one 219 */ 220 switch(pmac_i2c_get_type(bus)) { 221 case pmac_i2c_bus_keywest: 222 parent = of_get_parent(pmac_i2c_get_controller(bus)); 223 if (parent == NULL) 224 return -EINVAL; 225 basename = parent->name; 226 break; 227 case pmac_i2c_bus_pmu: 228 basename = "pmu"; 229 break; 230 case pmac_i2c_bus_smu: 231 /* This is not what we used to do but I'm fixing drivers at 232 * the same time as this change 233 */ 234 basename = "smu"; 235 break; 236 default: 237 return -EINVAL; 238 } 239 snprintf(name, 32, "%s %d", basename, pmac_i2c_get_channel(bus)); 240 of_node_put(parent); 241 242 adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); 243 if (adapter == NULL) { 244 printk(KERN_ERR "i2c-powermac: can't allocate inteface !\n"); 245 return -ENOMEM; 246 } 247 platform_set_drvdata(dev, adapter); 248 strcpy(adapter->name, name); 249 adapter->algo = &i2c_powermac_algorithm; 250 i2c_set_adapdata(adapter, bus); 251 adapter->dev.parent = &dev->dev; 252 pmac_i2c_attach_adapter(bus, adapter); 253 rc = i2c_add_adapter(adapter); 254 if (rc) { 255 printk(KERN_ERR "i2c-powermac: Adapter %s registration " 256 "failed\n", name); 257 i2c_set_adapdata(adapter, NULL); 258 pmac_i2c_detach_adapter(bus, adapter); 259 } 260 261 printk(KERN_INFO "PowerMac i2c bus %s registered\n", name); 262 263 if (!strncmp(basename, "uni-n", 5)) { 264 struct device_node *np; 265 const u32 *prop; 266 struct i2c_board_info info; 267 268 /* Instantiate I2C motion sensor if present */ 269 np = of_find_node_by_name(NULL, "accelerometer"); 270 if (np && of_device_is_compatible(np, "AAPL,accelerometer_1") && 271 (prop = of_get_property(np, "reg", NULL))) { 272 int i2c_bus; 273 const char *tmp_bus; 274 275 /* look for bus either using "reg" or by path */ 276 tmp_bus = strstr(np->full_name, "/i2c-bus@"); 277 if (tmp_bus) 278 i2c_bus = *(tmp_bus + 9) - '0'; 279 else 280 i2c_bus = ((*prop) >> 8) & 0x0f; 281 282 if (pmac_i2c_get_channel(bus) == i2c_bus) { 283 memset(&info, 0, sizeof(struct i2c_board_info)); 284 info.addr = ((*prop) & 0xff) >> 1; 285 strlcpy(info.type, "ams", I2C_NAME_SIZE); 286 i2c_new_device(adapter, &info); 287 } 288 } 289 } 290 291 return rc; 292 } 293 294 295 /* work with hotplug and coldplug */ 296 MODULE_ALIAS("platform:i2c-powermac"); 297 298 static struct platform_driver i2c_powermac_driver = { 299 .probe = i2c_powermac_probe, 300 .remove = __devexit_p(i2c_powermac_remove), 301 .driver = { 302 .name = "i2c-powermac", 303 .bus = &platform_bus_type, 304 }, 305 }; 306 307 static int __init i2c_powermac_init(void) 308 { 309 platform_driver_register(&i2c_powermac_driver); 310 return 0; 311 } 312 313 314 static void __exit i2c_powermac_cleanup(void) 315 { 316 platform_driver_unregister(&i2c_powermac_driver); 317 } 318 319 module_init(i2c_powermac_init); 320 module_exit(i2c_powermac_cleanup); 321