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/config.h> 24 #include <linux/module.h> 25 #include <linux/kernel.h> 26 #include <linux/types.h> 27 #include <linux/i2c.h> 28 #include <linux/init.h> 29 #include <linux/completion.h> 30 #include <linux/device.h> 31 #include <linux/platform_device.h> 32 #include <asm/prom.h> 33 #include <asm/pmac_low_i2c.h> 34 35 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 36 MODULE_DESCRIPTION("I2C driver for Apple PowerMac"); 37 MODULE_LICENSE("GPL"); 38 39 /* 40 * SMBUS-type transfer entrypoint 41 */ 42 static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap, 43 u16 addr, 44 unsigned short flags, 45 char read_write, 46 u8 command, 47 int size, 48 union i2c_smbus_data* data) 49 { 50 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 51 int rc = 0; 52 int read = (read_write == I2C_SMBUS_READ); 53 int addrdir = (addr << 1) | read; 54 u8 local[2]; 55 56 rc = pmac_i2c_open(bus, 0); 57 if (rc) 58 return rc; 59 60 switch (size) { 61 case I2C_SMBUS_QUICK: 62 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 63 if (rc) 64 goto bail; 65 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, NULL, 0); 66 break; 67 case I2C_SMBUS_BYTE: 68 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 69 if (rc) 70 goto bail; 71 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, &data->byte, 1); 72 break; 73 case I2C_SMBUS_BYTE_DATA: 74 rc = pmac_i2c_setmode(bus, read ? 75 pmac_i2c_mode_combined : 76 pmac_i2c_mode_stdsub); 77 if (rc) 78 goto bail; 79 rc = pmac_i2c_xfer(bus, addrdir, 1, command, &data->byte, 1); 80 break; 81 case I2C_SMBUS_WORD_DATA: 82 rc = pmac_i2c_setmode(bus, read ? 83 pmac_i2c_mode_combined : 84 pmac_i2c_mode_stdsub); 85 if (rc) 86 goto bail; 87 if (!read) { 88 local[0] = data->word & 0xff; 89 local[1] = (data->word >> 8) & 0xff; 90 } 91 rc = pmac_i2c_xfer(bus, addrdir, 1, command, local, 2); 92 if (rc == 0 && read) { 93 data->word = ((u16)local[1]) << 8; 94 data->word |= local[0]; 95 } 96 break; 97 98 /* Note that these are broken vs. the expected smbus API where 99 * on reads, the lenght is actually returned from the function, 100 * but I think the current API makes no sense and I don't want 101 * any driver that I haven't verified for correctness to go 102 * anywhere near a pmac i2c bus anyway ... 103 * 104 * I'm also not completely sure what kind of phases to do between 105 * the actual command and the data (what I am _supposed_ to do that 106 * is). For now, I assume writes are a single stream and reads have 107 * a repeat start/addr phase (but not stop in between) 108 */ 109 case I2C_SMBUS_BLOCK_DATA: 110 rc = pmac_i2c_setmode(bus, read ? 111 pmac_i2c_mode_combined : 112 pmac_i2c_mode_stdsub); 113 if (rc) 114 goto bail; 115 rc = pmac_i2c_xfer(bus, addrdir, 1, command, data->block, 116 data->block[0] + 1); 117 118 break; 119 case I2C_SMBUS_I2C_BLOCK_DATA: 120 rc = pmac_i2c_setmode(bus, read ? 121 pmac_i2c_mode_combined : 122 pmac_i2c_mode_stdsub); 123 if (rc) 124 goto bail; 125 rc = pmac_i2c_xfer(bus, addrdir, 1, command, 126 read ? data->block : &data->block[1], 127 data->block[0]); 128 break; 129 130 default: 131 rc = -EINVAL; 132 } 133 bail: 134 pmac_i2c_close(bus); 135 return rc; 136 } 137 138 /* 139 * Generic i2c master transfer entrypoint. This driver only support single 140 * messages (for "lame i2c" transfers). Anything else should use the smbus 141 * entry point 142 */ 143 static int i2c_powermac_master_xfer( struct i2c_adapter *adap, 144 struct i2c_msg *msgs, 145 int num) 146 { 147 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 148 int rc = 0; 149 int read; 150 int addrdir; 151 152 if (num != 1) 153 return -EINVAL; 154 if (msgs->flags & I2C_M_TEN) 155 return -EINVAL; 156 read = (msgs->flags & I2C_M_RD) != 0; 157 addrdir = (msgs->addr << 1) | read; 158 if (msgs->flags & I2C_M_REV_DIR_ADDR) 159 addrdir ^= 1; 160 161 rc = pmac_i2c_open(bus, 0); 162 if (rc) 163 return rc; 164 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 165 if (rc) 166 goto bail; 167 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len); 168 bail: 169 pmac_i2c_close(bus); 170 return rc < 0 ? rc : msgs->len; 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 struct i2c_algorithm i2c_powermac_algorithm = { 182 .smbus_xfer = i2c_powermac_smbus_xfer, 183 .master_xfer = i2c_powermac_master_xfer, 184 .functionality = i2c_powermac_func, 185 }; 186 187 188 static int i2c_powermac_remove(struct device *dev) 189 { 190 struct i2c_adapter *adapter = dev_get_drvdata(dev); 191 struct pmac_i2c_bus *bus = i2c_get_adapdata(adapter); 192 int rc; 193 194 rc = i2c_del_adapter(adapter); 195 pmac_i2c_detach_adapter(bus, adapter); 196 i2c_set_adapdata(adapter, NULL); 197 /* We aren't that prepared to deal with this... */ 198 if (rc) 199 printk("i2c-powermac.c: Failed to remove bus %s !\n", 200 adapter->name); 201 dev_set_drvdata(dev, NULL); 202 kfree(adapter); 203 204 return 0; 205 } 206 207 208 static int i2c_powermac_probe(struct device *dev) 209 { 210 struct pmac_i2c_bus *bus = dev->platform_data; 211 struct device_node *parent = NULL; 212 struct i2c_adapter *adapter; 213 char name[32], *basename; 214 int rc; 215 216 if (bus == NULL) 217 return -EINVAL; 218 219 /* Ok, now we need to make up a name for the interface that will 220 * match what we used to do in the past, that is basically the 221 * controller's parent device node for keywest. PMU didn't have a 222 * naming convention and SMU has a different one 223 */ 224 switch(pmac_i2c_get_type(bus)) { 225 case pmac_i2c_bus_keywest: 226 parent = of_get_parent(pmac_i2c_get_controller(bus)); 227 if (parent == NULL) 228 return -EINVAL; 229 basename = parent->name; 230 break; 231 case pmac_i2c_bus_pmu: 232 basename = "pmu"; 233 break; 234 case pmac_i2c_bus_smu: 235 /* This is not what we used to do but I'm fixing drivers at 236 * the same time as this change 237 */ 238 basename = "smu"; 239 break; 240 default: 241 return -EINVAL; 242 } 243 snprintf(name, 32, "%s %d", basename, pmac_i2c_get_channel(bus)); 244 of_node_put(parent); 245 246 adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); 247 if (adapter == NULL) { 248 printk(KERN_ERR "i2c-powermac: can't allocate inteface !\n"); 249 return -ENOMEM; 250 } 251 dev_set_drvdata(dev, adapter); 252 strcpy(adapter->name, name); 253 adapter->algo = &i2c_powermac_algorithm; 254 i2c_set_adapdata(adapter, bus); 255 adapter->dev.parent = dev; 256 pmac_i2c_attach_adapter(bus, adapter); 257 rc = i2c_add_adapter(adapter); 258 if (rc) { 259 printk(KERN_ERR "i2c-powermac: Adapter %s registration " 260 "failed\n", name); 261 i2c_set_adapdata(adapter, NULL); 262 pmac_i2c_detach_adapter(bus, adapter); 263 } 264 265 printk(KERN_INFO "PowerMac i2c bus %s registered\n", name); 266 return rc; 267 } 268 269 270 static struct device_driver i2c_powermac_driver = { 271 .name = "i2c-powermac", 272 .bus = &platform_bus_type, 273 .probe = i2c_powermac_probe, 274 .remove = i2c_powermac_remove, 275 }; 276 277 static int __init i2c_powermac_init(void) 278 { 279 driver_register(&i2c_powermac_driver); 280 return 0; 281 } 282 283 284 static void __exit i2c_powermac_cleanup(void) 285 { 286 driver_unregister(&i2c_powermac_driver); 287 } 288 289 module_init(i2c_powermac_init); 290 module_exit(i2c_powermac_cleanup); 291