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 */
i2c_powermac_smbus_xfer(struct i2c_adapter * adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)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 */
i2c_powermac_master_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)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
i2c_powermac_func(struct i2c_adapter * adapter)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
i2c_powermac_remove(struct platform_device * dev)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
i2c_powermac_probe(struct platform_device * dev)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 static struct platform_driver i2c_powermac_driver = {
316 .probe = i2c_powermac_probe,
317 .remove = __devexit_p(i2c_powermac_remove),
318 .driver = {
319 .name = "i2c-powermac",
320 .bus = &platform_bus_type,
321 },
322 };
323
324 module_platform_driver(i2c_powermac_driver);
325
326 MODULE_ALIAS("platform:i2c-powermac");
327