Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6
[linux-2.6] / 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/completion.h>
29 #include <linux/device.h>
30 #include <linux/platform_device.h>
31 #include <asm/prom.h>
32 #include <asm/pmac_low_i2c.h>
33
34 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
35 MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
36 MODULE_LICENSE("GPL");
37
38 /*
39  * SMBUS-type transfer entrypoint
40  */
41 static s32 i2c_powermac_smbus_xfer(     struct i2c_adapter*     adap,
42                                         u16                     addr,
43                                         unsigned short          flags,
44                                         char                    read_write,
45                                         u8                      command,
46                                         int                     size,
47                                         union i2c_smbus_data*   data)
48 {
49         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
50         int                     rc = 0;
51         int                     read = (read_write == I2C_SMBUS_READ);
52         int                     addrdir = (addr << 1) | read;
53         u8                      local[2];
54
55         rc = pmac_i2c_open(bus, 0);
56         if (rc)
57                 return rc;
58
59         switch (size) {
60         case I2C_SMBUS_QUICK:
61                 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
62                 if (rc)
63                         goto bail;
64                 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, NULL, 0);
65                 break;
66         case I2C_SMBUS_BYTE:
67                 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
68                 if (rc)
69                         goto bail;
70                 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, &data->byte, 1);
71                 break;
72         case I2C_SMBUS_BYTE_DATA:
73                 rc = pmac_i2c_setmode(bus, read ?
74                                       pmac_i2c_mode_combined :
75                                       pmac_i2c_mode_stdsub);
76                 if (rc)
77                         goto bail;
78                 rc = pmac_i2c_xfer(bus, addrdir, 1, command, &data->byte, 1);
79                 break;
80         case I2C_SMBUS_WORD_DATA:
81                 rc = pmac_i2c_setmode(bus, read ?
82                                       pmac_i2c_mode_combined :
83                                       pmac_i2c_mode_stdsub);
84                 if (rc)
85                         goto bail;
86                 if (!read) {
87                         local[0] = data->word & 0xff;
88                         local[1] = (data->word >> 8) & 0xff;
89                 }
90                 rc = pmac_i2c_xfer(bus, addrdir, 1, command, local, 2);
91                 if (rc == 0 && read) {
92                         data->word = ((u16)local[1]) << 8;
93                         data->word |= local[0];
94                 }
95                 break;
96
97         /* Note that these are broken vs. the expected smbus API where
98          * on reads, the lenght is actually returned from the function,
99          * but I think the current API makes no sense and I don't want
100          * any driver that I haven't verified for correctness to go
101          * anywhere near a pmac i2c bus anyway ...
102          *
103          * I'm also not completely sure what kind of phases to do between
104          * the actual command and the data (what I am _supposed_ to do that
105          * is). For now, I assume writes are a single stream and reads have
106          * a repeat start/addr phase (but not stop in between)
107          */
108         case I2C_SMBUS_BLOCK_DATA:
109                 rc = pmac_i2c_setmode(bus, read ?
110                                       pmac_i2c_mode_combined :
111                                       pmac_i2c_mode_stdsub);
112                 if (rc)
113                         goto bail;
114                 rc = pmac_i2c_xfer(bus, addrdir, 1, command, data->block,
115                                    data->block[0] + 1);
116
117                 break;
118         case I2C_SMBUS_I2C_BLOCK_DATA:
119                 rc = pmac_i2c_setmode(bus, read ?
120                                       pmac_i2c_mode_combined :
121                                       pmac_i2c_mode_stdsub);
122                 if (rc)
123                         goto bail;
124                 rc = pmac_i2c_xfer(bus, addrdir, 1, command,
125                                    read ? data->block : &data->block[1],
126                                    data->block[0]);
127                 break;
128
129         default:
130                 rc = -EINVAL;
131         }
132  bail:
133         pmac_i2c_close(bus);
134         return rc;
135 }
136
137 /*
138  * Generic i2c master transfer entrypoint. This driver only support single
139  * messages (for "lame i2c" transfers). Anything else should use the smbus
140  * entry point
141  */
142 static int i2c_powermac_master_xfer(    struct i2c_adapter *adap,
143                                         struct i2c_msg *msgs,
144                                         int num)
145 {
146         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
147         int                     rc = 0;
148         int                     read;
149         int                     addrdir;
150
151         if (msgs->flags & I2C_M_TEN)
152                 return -EINVAL;
153         read = (msgs->flags & I2C_M_RD) != 0;
154         addrdir = (msgs->addr << 1) | read;
155         if (msgs->flags & I2C_M_REV_DIR_ADDR)
156                 addrdir ^= 1;
157
158         rc = pmac_i2c_open(bus, 0);
159         if (rc)
160                 return rc;
161         rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
162         if (rc)
163                 goto bail;
164         rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
165  bail:
166         pmac_i2c_close(bus);
167         return rc < 0 ? rc : 1;
168 }
169
170 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
171 {
172         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
173                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
174                 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
175 }
176
177 /* For now, we only handle smbus */
178 static struct i2c_algorithm i2c_powermac_algorithm = {
179         .smbus_xfer     = i2c_powermac_smbus_xfer,
180         .master_xfer    = i2c_powermac_master_xfer,
181         .functionality  = i2c_powermac_func,
182 };
183
184
185 static int i2c_powermac_remove(struct device *dev)
186 {
187         struct i2c_adapter      *adapter = dev_get_drvdata(dev);
188         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adapter);
189         int                     rc;
190
191         rc = i2c_del_adapter(adapter);
192         pmac_i2c_detach_adapter(bus, adapter);
193         i2c_set_adapdata(adapter, NULL);
194         /* We aren't that prepared to deal with this... */
195         if (rc)
196                 printk("i2c-powermac.c: Failed to remove bus %s !\n",
197                        adapter->name);
198         dev_set_drvdata(dev, NULL);
199         kfree(adapter);
200
201         return 0;
202 }
203
204
205 static int i2c_powermac_probe(struct device *dev)
206 {
207         struct pmac_i2c_bus *bus = dev->platform_data;
208         struct device_node *parent = NULL;
209         struct i2c_adapter *adapter;
210         char name[32];
211         const char *basename;
212         int rc;
213
214         if (bus == NULL)
215                 return -EINVAL;
216
217         /* Ok, now we need to make up a name for the interface that will
218          * match what we used to do in the past, that is basically the
219          * controller's parent device node for keywest. PMU didn't have a
220          * naming convention and SMU has a different one
221          */
222         switch(pmac_i2c_get_type(bus)) {
223         case pmac_i2c_bus_keywest:
224                 parent = of_get_parent(pmac_i2c_get_controller(bus));
225                 if (parent == NULL)
226                         return -EINVAL;
227                 basename = parent->name;
228                 break;
229         case pmac_i2c_bus_pmu:
230                 basename = "pmu";
231                 break;
232         case pmac_i2c_bus_smu:
233                 /* This is not what we used to do but I'm fixing drivers at
234                  * the same time as this change
235                  */
236                 basename = "smu";
237                 break;
238         default:
239                 return -EINVAL;
240         }
241         snprintf(name, 32, "%s %d", basename, pmac_i2c_get_channel(bus));
242         of_node_put(parent);
243
244         adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
245         if (adapter == NULL) {
246                 printk(KERN_ERR "i2c-powermac: can't allocate inteface !\n");
247                 return -ENOMEM;
248         }
249         dev_set_drvdata(dev, adapter);
250         strcpy(adapter->name, name);
251         adapter->algo = &i2c_powermac_algorithm;
252         i2c_set_adapdata(adapter, bus);
253         adapter->dev.parent = dev;
254         pmac_i2c_attach_adapter(bus, adapter);
255         rc = i2c_add_adapter(adapter);
256         if (rc) {
257                 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
258                        "failed\n", name);
259                 i2c_set_adapdata(adapter, NULL);
260                 pmac_i2c_detach_adapter(bus, adapter);
261         }
262
263         printk(KERN_INFO "PowerMac i2c bus %s registered\n", name);
264         return rc;
265 }
266
267
268 static struct device_driver i2c_powermac_driver = {
269         .name = "i2c-powermac",
270         .bus = &platform_bus_type,
271         .probe = i2c_powermac_probe,
272         .remove = i2c_powermac_remove,
273 };
274
275 static int __init i2c_powermac_init(void)
276 {
277         driver_register(&i2c_powermac_driver);
278         return 0;
279 }
280
281
282 static void __exit i2c_powermac_cleanup(void)
283 {
284         driver_unregister(&i2c_powermac_driver);
285 }
286
287 module_init(i2c_powermac_init);
288 module_exit(i2c_powermac_cleanup);