Pileus Git - ~andy/linux/blob - drivers/i2c/busses/i2c-powermac.c

   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                 return rc;
 113
 114         rc = pmac_i2c_setmode(bus, mode);
 115         if (rc)
 116                 goto bail;
 117
 118         rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len);
 119         if (rc)
 120                 goto bail;
 121
 122         if (size == I2C_SMBUS_WORD_DATA && read) {
 123                 data->word = ((u16)local[1]) << 8;
 124                 data->word |= local[0];
 125         }
 126
 127  bail:
 128         pmac_i2c_close(bus);
 129         return rc;
 130 }
 131
 132 /*
 133  * Generic i2c master transfer entrypoint. This driver only support single
 134  * messages (for "lame i2c" transfers). Anything else should use the smbus
 135  * entry point
 136  */
 137 static int i2c_powermac_master_xfer(    struct i2c_adapter *adap,
 138                                         struct i2c_msg *msgs,
 139                                         int num)
 140 {
 141         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
 142         int                     rc = 0;
 143         int                     read;
 144         int                     addrdir;
 145
 146         if (num != 1) {
 147                 dev_err(&adap->dev,
 148                         "Multi-message I2C transactions not supported\n");
 149                 return -EOPNOTSUPP;
 150         }
 151
 152         if (msgs->flags & I2C_M_TEN)
 153                 return -EINVAL;
 154         read = (msgs->flags & I2C_M_RD) != 0;
 155         addrdir = (msgs->addr << 1) | read;
 156         if (msgs->flags & I2C_M_REV_DIR_ADDR)
 157                 addrdir ^= 1;
 158
 159         rc = pmac_i2c_open(bus, 0);
 160         if (rc)
 161                 return rc;
 162         rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
 163         if (rc)
 164                 goto bail;
 165         rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
 166  bail:
 167         pmac_i2c_close(bus);
 168         return rc < 0 ? rc : 1;
 169 }
 170
 171 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
 172 {
 173         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 174                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 175                 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
 176 }
 177
 178 /* For now, we only handle smbus */
 179 static const struct i2c_algorithm i2c_powermac_algorithm = {
 180         .smbus_xfer     = i2c_powermac_smbus_xfer,
 181         .master_xfer    = i2c_powermac_master_xfer,
 182         .functionality  = i2c_powermac_func,
 183 };
 184
 185
 186 static int __devexit i2c_powermac_remove(struct platform_device *dev)
 187 {
 188         struct i2c_adapter      *adapter = platform_get_drvdata(dev);
 189         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adapter);
 190         int                     rc;
 191
 192         rc = i2c_del_adapter(adapter);
 193         pmac_i2c_detach_adapter(bus, adapter);
 194         i2c_set_adapdata(adapter, NULL);
 195         /* We aren't that prepared to deal with this... */
 196         if (rc)
 197                 printk(KERN_WARNING
 198                        "i2c-powermac.c: Failed to remove bus %s !\n",
 199                        adapter->name);
 200         platform_set_drvdata(dev, NULL);
 201         kfree(adapter);
 202
 203         return 0;
 204 }
 205
 206
 207 static int __devinit i2c_powermac_probe(struct platform_device *dev)
 208 {
 209         struct pmac_i2c_bus *bus = dev->dev.platform_data;
 210         struct device_node *parent = NULL;
 211         struct i2c_adapter *adapter;
 212         char name[32];
 213         const char *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         platform_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->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
 267         if (!strncmp(basename, "uni-n", 5)) {
 268                 struct device_node *np;
 269                 const u32 *prop;
 270                 struct i2c_board_info info;
 271
 272                 /* Instantiate I2C motion sensor if present */
 273                 np = of_find_node_by_name(NULL, "accelerometer");
 274                 if (np && of_device_is_compatible(np, "AAPL,accelerometer_1") &&
 275                     (prop = of_get_property(np, "reg", NULL))) {
 276                         int i2c_bus;
 277                         const char *tmp_bus;
 278
 279                         /* look for bus either using "reg" or by path */
 280                         tmp_bus = strstr(np->full_name, "/i2c-bus@");
 281                         if (tmp_bus)
 282                                 i2c_bus = *(tmp_bus + 9) - '0';
 283                         else
 284                                 i2c_bus = ((*prop) >> 8) & 0x0f;
 285
 286                         if (pmac_i2c_get_channel(bus) == i2c_bus) {
 287                                 memset(&info, 0, sizeof(struct i2c_board_info));
 288                                 info.addr = ((*prop) & 0xff) >> 1;
 289                                 strlcpy(info.type, "ams", I2C_NAME_SIZE);
 290                                 i2c_new_device(adapter, &info);
 291                         }
 292                 }
 293         }
 294
 295         return rc;
 296 }
 297
 298
 299 /* work with hotplug and coldplug */
 300 MODULE_ALIAS("platform:i2c-powermac");
 301
 302 static struct platform_driver i2c_powermac_driver = {
 303         .probe = i2c_powermac_probe,
 304         .remove = __devexit_p(i2c_powermac_remove),
 305         .driver = {
 306                 .name = "i2c-powermac",
 307                 .bus = &platform_bus_type,
 308         },
 309 };
 310
 311 static int __init i2c_powermac_init(void)
 312 {
 313         platform_driver_register(&i2c_powermac_driver);
 314         return 0;
 315 }
 316
 317
 318 static void __exit i2c_powermac_cleanup(void)
 319 {
 320         platform_driver_unregister(&i2c_powermac_driver);
 321 }
 322
 323 module_init(i2c_powermac_init);
 324 module_exit(i2c_powermac_cleanup);