Merge branch 'kprobes' of git://git.linaro.org/people/nico/linux into fixes
[pandora-kernel.git] / 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                 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                 if (rc == -ENXIO)
126                         dev_dbg(&adap->dev,
127                                 "I2C transfer at 0x%02x failed, size %d, "
128                                 "err %d\n", addrdir >> 1, size, rc);
129                 else
130                         dev_err(&adap->dev,
131                                 "I2C transfer at 0x%02x failed, size %d, "
132                                 "err %d\n", addrdir >> 1, size, rc);
133                 goto bail;
134         }
135
136         if (size == I2C_SMBUS_WORD_DATA && read) {
137                 data->word = ((u16)local[1]) << 8;
138                 data->word |= local[0];
139         }
140
141  bail:
142         pmac_i2c_close(bus);
143         return rc;
144 }
145
146 /*
147  * Generic i2c master transfer entrypoint. This driver only support single
148  * messages (for "lame i2c" transfers). Anything else should use the smbus
149  * entry point
150  */
151 static int i2c_powermac_master_xfer(    struct i2c_adapter *adap,
152                                         struct i2c_msg *msgs,
153                                         int num)
154 {
155         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
156         int                     rc = 0;
157         int                     read;
158         int                     addrdir;
159
160         if (num != 1) {
161                 dev_err(&adap->dev,
162                         "Multi-message I2C transactions not supported\n");
163                 return -EOPNOTSUPP;
164         }
165
166         if (msgs->flags & I2C_M_TEN)
167                 return -EINVAL;
168         read = (msgs->flags & I2C_M_RD) != 0;
169         addrdir = (msgs->addr << 1) | read;
170
171         rc = pmac_i2c_open(bus, 0);
172         if (rc) {
173                 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
174                 return rc;
175         }
176         rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
177         if (rc) {
178                 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
179                         pmac_i2c_mode_std, rc);
180                 goto bail;
181         }
182         rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
183         if (rc < 0) {
184                 if (rc == -ENXIO)
185                         dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
186                                 addrdir & 1 ? "read from" : "write to",
187                                 addrdir >> 1, rc);
188                 else
189                         dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
190                                 addrdir & 1 ? "read from" : "write to",
191                                 addrdir >> 1, rc);
192         }
193  bail:
194         pmac_i2c_close(bus);
195         return rc < 0 ? rc : 1;
196 }
197
198 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
199 {
200         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
201                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
202                 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
203 }
204
205 /* For now, we only handle smbus */
206 static const struct i2c_algorithm i2c_powermac_algorithm = {
207         .smbus_xfer     = i2c_powermac_smbus_xfer,
208         .master_xfer    = i2c_powermac_master_xfer,
209         .functionality  = i2c_powermac_func,
210 };
211
212
213 static int __devexit i2c_powermac_remove(struct platform_device *dev)
214 {
215         struct i2c_adapter      *adapter = platform_get_drvdata(dev);
216         int                     rc;
217
218         rc = i2c_del_adapter(adapter);
219         /* We aren't that prepared to deal with this... */
220         if (rc)
221                 printk(KERN_WARNING
222                        "i2c-powermac.c: Failed to remove bus %s !\n",
223                        adapter->name);
224         platform_set_drvdata(dev, NULL);
225         memset(adapter, 0, sizeof(*adapter));
226
227         return 0;
228 }
229
230
231 static int __devinit i2c_powermac_probe(struct platform_device *dev)
232 {
233         struct pmac_i2c_bus *bus = dev->dev.platform_data;
234         struct device_node *parent = NULL;
235         struct i2c_adapter *adapter;
236         const char *basename;
237         int rc;
238
239         if (bus == NULL)
240                 return -EINVAL;
241         adapter = pmac_i2c_get_adapter(bus);
242
243         /* Ok, now we need to make up a name for the interface that will
244          * match what we used to do in the past, that is basically the
245          * controller's parent device node for keywest. PMU didn't have a
246          * naming convention and SMU has a different one
247          */
248         switch(pmac_i2c_get_type(bus)) {
249         case pmac_i2c_bus_keywest:
250                 parent = of_get_parent(pmac_i2c_get_controller(bus));
251                 if (parent == NULL)
252                         return -EINVAL;
253                 basename = parent->name;
254                 break;
255         case pmac_i2c_bus_pmu:
256                 basename = "pmu";
257                 break;
258         case pmac_i2c_bus_smu:
259                 /* This is not what we used to do but I'm fixing drivers at
260                  * the same time as this change
261                  */
262                 basename = "smu";
263                 break;
264         default:
265                 return -EINVAL;
266         }
267         snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
268                  pmac_i2c_get_channel(bus));
269         of_node_put(parent);
270
271         platform_set_drvdata(dev, adapter);
272         adapter->algo = &i2c_powermac_algorithm;
273         i2c_set_adapdata(adapter, bus);
274         adapter->dev.parent = &dev->dev;
275         rc = i2c_add_adapter(adapter);
276         if (rc) {
277                 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
278                        "failed\n", adapter->name);
279                 memset(adapter, 0, sizeof(*adapter));
280         }
281
282         printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
283
284         if (!strncmp(basename, "uni-n", 5)) {
285                 struct device_node *np;
286                 const u32 *prop;
287                 struct i2c_board_info info;
288
289                 /* Instantiate I2C motion sensor if present */
290                 np = of_find_node_by_name(NULL, "accelerometer");
291                 if (np && of_device_is_compatible(np, "AAPL,accelerometer_1") &&
292                     (prop = of_get_property(np, "reg", NULL))) {
293                         int i2c_bus;
294                         const char *tmp_bus;
295
296                         /* look for bus either using "reg" or by path */
297                         tmp_bus = strstr(np->full_name, "/i2c-bus@");
298                         if (tmp_bus)
299                                 i2c_bus = *(tmp_bus + 9) - '0';
300                         else
301                                 i2c_bus = ((*prop) >> 8) & 0x0f;
302
303                         if (pmac_i2c_get_channel(bus) == i2c_bus) {
304                                 memset(&info, 0, sizeof(struct i2c_board_info));
305                                 info.addr = ((*prop) & 0xff) >> 1;
306                                 strlcpy(info.type, "ams", I2C_NAME_SIZE);
307                                 i2c_new_device(adapter, &info);
308                         }
309                 }
310         }
311
312         return rc;
313 }
314
315
316 /* work with hotplug and coldplug */
317 MODULE_ALIAS("platform:i2c-powermac");
318
319 static struct platform_driver i2c_powermac_driver = {
320         .probe = i2c_powermac_probe,
321         .remove = __devexit_p(i2c_powermac_remove),
322         .driver = {
323                 .name = "i2c-powermac",
324                 .bus = &platform_bus_type,
325         },
326 };
327
328 static int __init i2c_powermac_init(void)
329 {
330         platform_driver_register(&i2c_powermac_driver);
331         return 0;
332 }
333
334
335 static void __exit i2c_powermac_cleanup(void)
336 {
337         platform_driver_unregister(&i2c_powermac_driver);
338 }
339
340 module_init(i2c_powermac_init);
341 module_exit(i2c_powermac_cleanup);