i2c: Fix the i2c_smbus_read_i2c_block_data() prototype
[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                                    &data->block[1], data->block[0]);
125                 break;
126
127         default:
128                 rc = -EINVAL;
129         }
130  bail:
131         pmac_i2c_close(bus);
132         return rc;
133 }
134
135 /*
136  * Generic i2c master transfer entrypoint. This driver only support single
137  * messages (for "lame i2c" transfers). Anything else should use the smbus
138  * entry point
139  */
140 static int i2c_powermac_master_xfer(    struct i2c_adapter *adap,
141                                         struct i2c_msg *msgs,
142                                         int num)
143 {
144         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
145         int                     rc = 0;
146         int                     read;
147         int                     addrdir;
148
149         if (msgs->flags & I2C_M_TEN)
150                 return -EINVAL;
151         read = (msgs->flags & I2C_M_RD) != 0;
152         addrdir = (msgs->addr << 1) | read;
153         if (msgs->flags & I2C_M_REV_DIR_ADDR)
154                 addrdir ^= 1;
155
156         rc = pmac_i2c_open(bus, 0);
157         if (rc)
158                 return rc;
159         rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
160         if (rc)
161                 goto bail;
162         rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
163  bail:
164         pmac_i2c_close(bus);
165         return rc < 0 ? rc : 1;
166 }
167
168 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
169 {
170         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
171                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
172                 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
173 }
174
175 /* For now, we only handle smbus */
176 static const struct i2c_algorithm i2c_powermac_algorithm = {
177         .smbus_xfer     = i2c_powermac_smbus_xfer,
178         .master_xfer    = i2c_powermac_master_xfer,
179         .functionality  = i2c_powermac_func,
180 };
181
182
183 static int i2c_powermac_remove(struct platform_device *dev)
184 {
185         struct i2c_adapter      *adapter = platform_get_drvdata(dev);
186         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adapter);
187         int                     rc;
188
189         rc = i2c_del_adapter(adapter);
190         pmac_i2c_detach_adapter(bus, adapter);
191         i2c_set_adapdata(adapter, NULL);
192         /* We aren't that prepared to deal with this... */
193         if (rc)
194                 printk("i2c-powermac.c: Failed to remove bus %s !\n",
195                        adapter->name);
196         platform_set_drvdata(dev, NULL);
197         kfree(adapter);
198
199         return 0;
200 }
201
202
203 static int __devexit i2c_powermac_probe(struct platform_device *dev)
204 {
205         struct pmac_i2c_bus *bus = dev->dev.platform_data;
206         struct device_node *parent = NULL;
207         struct i2c_adapter *adapter;
208         char name[32];
209         const char *basename;
210         int rc;
211
212         if (bus == NULL)
213                 return -EINVAL;
214
215         /* Ok, now we need to make up a name for the interface that will
216          * match what we used to do in the past, that is basically the
217          * controller's parent device node for keywest. PMU didn't have a
218          * naming convention and SMU has a different one
219          */
220         switch(pmac_i2c_get_type(bus)) {
221         case pmac_i2c_bus_keywest:
222                 parent = of_get_parent(pmac_i2c_get_controller(bus));
223                 if (parent == NULL)
224                         return -EINVAL;
225                 basename = parent->name;
226                 break;
227         case pmac_i2c_bus_pmu:
228                 basename = "pmu";
229                 break;
230         case pmac_i2c_bus_smu:
231                 /* This is not what we used to do but I'm fixing drivers at
232                  * the same time as this change
233                  */
234                 basename = "smu";
235                 break;
236         default:
237                 return -EINVAL;
238         }
239         snprintf(name, 32, "%s %d", basename, pmac_i2c_get_channel(bus));
240         of_node_put(parent);
241
242         adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
243         if (adapter == NULL) {
244                 printk(KERN_ERR "i2c-powermac: can't allocate inteface !\n");
245                 return -ENOMEM;
246         }
247         platform_set_drvdata(dev, adapter);
248         strcpy(adapter->name, name);
249         adapter->algo = &i2c_powermac_algorithm;
250         i2c_set_adapdata(adapter, bus);
251         adapter->dev.parent = &dev->dev;
252         pmac_i2c_attach_adapter(bus, adapter);
253         rc = i2c_add_adapter(adapter);
254         if (rc) {
255                 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
256                        "failed\n", name);
257                 i2c_set_adapdata(adapter, NULL);
258                 pmac_i2c_detach_adapter(bus, adapter);
259         }
260
261         printk(KERN_INFO "PowerMac i2c bus %s registered\n", name);
262         return rc;
263 }
264
265
266 static struct platform_driver i2c_powermac_driver = {
267         .probe = i2c_powermac_probe,
268         .remove = __devexit_p(i2c_powermac_remove),
269         .driver = {
270                 .name = "i2c-powermac",
271                 .bus = &platform_bus_type,
272         },
273 };
274
275 static int __init i2c_powermac_init(void)
276 {
277         platform_driver_register(&i2c_powermac_driver);
278         return 0;
279 }
280
281
282 static void __exit i2c_powermac_cleanup(void)
283 {
284         platform_driver_unregister(&i2c_powermac_driver);
285 }
286
287 module_init(i2c_powermac_init);
288 module_exit(i2c_powermac_cleanup);