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