i2c: completion header cleanups
[linux-2.6.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         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);