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 lenght 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 read ? data->block : &data->block[1], 125 data->block[0]); 126 break; 127 128 default: 129 rc = -EINVAL; 130 } 131 bail: 132 pmac_i2c_close(bus); 133 return rc; 134 } 135 136 /* 137 * Generic i2c master transfer entrypoint. This driver only support single 138 * messages (for "lame i2c" transfers). Anything else should use the smbus 139 * entry point 140 */ 141 static int i2c_powermac_master_xfer( struct i2c_adapter *adap, 142 struct i2c_msg *msgs, 143 int num) 144 { 145 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 146 int rc = 0; 147 int read; 148 int addrdir; 149 150 if (msgs->flags & I2C_M_TEN) 151 return -EINVAL; 152 read = (msgs->flags & I2C_M_RD) != 0; 153 addrdir = (msgs->addr << 1) | read; 154 if (msgs->flags & I2C_M_REV_DIR_ADDR) 155 addrdir ^= 1; 156 157 rc = pmac_i2c_open(bus, 0); 158 if (rc) 159 return rc; 160 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 161 if (rc) 162 goto bail; 163 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len); 164 bail: 165 pmac_i2c_close(bus); 166 return rc < 0 ? rc : 1; 167 } 168 169 static u32 i2c_powermac_func(struct i2c_adapter * adapter) 170 { 171 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 172 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | 173 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C; 174 } 175 176 /* For now, we only handle smbus */ 177 static const struct i2c_algorithm i2c_powermac_algorithm = { 178 .smbus_xfer = i2c_powermac_smbus_xfer, 179 .master_xfer = i2c_powermac_master_xfer, 180 .functionality = i2c_powermac_func, 181 }; 182 183 184 static int i2c_powermac_remove(struct platform_device *dev) 185 { 186 struct i2c_adapter *adapter = platform_get_drvdata(dev); 187 struct pmac_i2c_bus *bus = i2c_get_adapdata(adapter); 188 int rc; 189 190 rc = i2c_del_adapter(adapter); 191 pmac_i2c_detach_adapter(bus, adapter); 192 i2c_set_adapdata(adapter, NULL); 193 /* We aren't that prepared to deal with this... */ 194 if (rc) 195 printk("i2c-powermac.c: Failed to remove bus %s !\n", 196 adapter->name); 197 platform_set_drvdata(dev, NULL); 198 kfree(adapter); 199 200 return 0; 201 } 202 203 204 static int __devexit i2c_powermac_probe(struct platform_device *dev) 205 { 206 struct pmac_i2c_bus *bus = dev->dev.platform_data; 207 struct device_node *parent = NULL; 208 struct i2c_adapter *adapter; 209 char name[32]; 210 const char *basename; 211 int rc; 212 213 if (bus == NULL) 214 return -EINVAL; 215 216 /* Ok, now we need to make up a name for the interface that will 217 * match what we used to do in the past, that is basically the 218 * controller's parent device node for keywest. PMU didn't have a 219 * naming convention and SMU has a different one 220 */ 221 switch(pmac_i2c_get_type(bus)) { 222 case pmac_i2c_bus_keywest: 223 parent = of_get_parent(pmac_i2c_get_controller(bus)); 224 if (parent == NULL) 225 return -EINVAL; 226 basename = parent->name; 227 break; 228 case pmac_i2c_bus_pmu: 229 basename = "pmu"; 230 break; 231 case pmac_i2c_bus_smu: 232 /* This is not what we used to do but I'm fixing drivers at 233 * the same time as this change 234 */ 235 basename = "smu"; 236 break; 237 default: 238 return -EINVAL; 239 } 240 snprintf(name, 32, "%s %d", basename, pmac_i2c_get_channel(bus)); 241 of_node_put(parent); 242 243 adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); 244 if (adapter == NULL) { 245 printk(KERN_ERR "i2c-powermac: can't allocate inteface !\n"); 246 return -ENOMEM; 247 } 248 platform_set_drvdata(dev, adapter); 249 strcpy(adapter->name, name); 250 adapter->algo = &i2c_powermac_algorithm; 251 i2c_set_adapdata(adapter, bus); 252 adapter->dev.parent = &dev->dev; 253 pmac_i2c_attach_adapter(bus, adapter); 254 rc = i2c_add_adapter(adapter); 255 if (rc) { 256 printk(KERN_ERR "i2c-powermac: Adapter %s registration " 257 "failed\n", name); 258 i2c_set_adapdata(adapter, NULL); 259 pmac_i2c_detach_adapter(bus, adapter); 260 } 261 262 printk(KERN_INFO "PowerMac i2c bus %s registered\n", name); 263 return rc; 264 } 265 266 267 static struct platform_driver i2c_powermac_driver = { 268 .probe = i2c_powermac_probe, 269 .remove = __devexit_p(i2c_powermac_remove), 270 .driver = { 271 .name = "i2c-powermac", 272 .bus = &platform_bus_type, 273 }, 274 }; 275 276 static int __init i2c_powermac_init(void) 277 { 278 platform_driver_register(&i2c_powermac_driver); 279 return 0; 280 } 281 282 283 static void __exit i2c_powermac_cleanup(void) 284 { 285 platform_driver_unregister(&i2c_powermac_driver); 286 } 287 288 module_init(i2c_powermac_init); 289 module_exit(i2c_powermac_cleanup); 290