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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
33MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
34MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
35MODULE_LICENSE("GPL");
36
37/*
38 * SMBUS-type transfer entrypoint
39 */
40static 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 */
151static 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
198static 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 */
206static 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
213static 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
230static u32 __devinit i2c_powermac_get_addr(struct i2c_adapter *adap,
231 struct pmac_i2c_bus *bus,
232 struct device_node *node)
233{
234 const __be32 *prop;
235 int len;
236
237 /* First check for valid "reg" */
238 prop = of_get_property(node, "reg", &len);
239 if (prop && (len >= sizeof(int)))
240 return (be32_to_cpup(prop) & 0xff) >> 1;
241
242 /* Then check old-style "i2c-address" */
243 prop = of_get_property(node, "i2c-address", &len);
244 if (prop && (len >= sizeof(int)))
245 return (be32_to_cpup(prop) & 0xff) >> 1;
246
247 /* Now handle some devices with missing "reg" properties */
248 if (!strcmp(node->name, "cereal"))
249 return 0x60;
250 else if (!strcmp(node->name, "deq"))
251 return 0x34;
252
253 dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name);
254
255 return 0xffffffff;
256}
257
258static void __devinit i2c_powermac_create_one(struct i2c_adapter *adap,
259 const char *type,
260 u32 addr)
261{
262 struct i2c_board_info info = {};
263 struct i2c_client *newdev;
264
265 strncpy(info.type, type, sizeof(info.type));
266 info.addr = addr;
267 newdev = i2c_new_device(adap, &info);
268 if (!newdev)
269 dev_err(&adap->dev,
270 "i2c-powermac: Failure to register missing %s\n",
271 type);
272}
273
274static void __devinit i2c_powermac_add_missing(struct i2c_adapter *adap,
275 struct pmac_i2c_bus *bus,
276 bool found_onyx)
277{
278 struct device_node *busnode = pmac_i2c_get_bus_node(bus);
279 int rc;
280
281 /* Check for the onyx audio codec */
282#define ONYX_REG_CONTROL 67
283 if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
284 union i2c_smbus_data data;
285
286 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
287 ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
288 &data);
289 if (rc >= 0)
290 i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
291
292 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
293 ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
294 &data);
295 if (rc >= 0)
296 i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
297 }
298}
299
300static bool __devinit i2c_powermac_get_type(struct i2c_adapter *adap,
301 struct device_node *node,
302 u32 addr, char *type, int type_size)
303{
304 char tmp[16];
305
306 /* Note: we to _NOT_ want the standard
307 * i2c drivers to match with any of our powermac stuff
308 * unless they have been specifically modified to handle
309 * it on a case by case basis. For example, for thermal
310 * control, things like lm75 etc... shall match with their
311 * corresponding windfarm drivers, _NOT_ the generic ones,
312 * so we force a prefix of AAPL, onto the modalias to
313 * make that happen
314 */
315
316 /* First try proper modalias */
317 if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
318 snprintf(type, type_size, "MAC,%s", tmp);
319 return true;
320 }
321
322 /* Now look for known workarounds */
323 if (!strcmp(node->name, "deq")) {
324 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
325 if (addr == 0x34) {
326 snprintf(type, type_size, "MAC,tas3001");
327 return true;
328 } else if (addr == 0x35) {
329 snprintf(type, type_size, "MAC,tas3004");
330 return true;
331 }
332 }
333
334 dev_err(&adap->dev, "i2c-powermac: modalias failure"
335 " on %s\n", node->full_name);
336 return false;
337}
338
339static void __devinit i2c_powermac_register_devices(struct i2c_adapter *adap,
340 struct pmac_i2c_bus *bus)
341{
342 struct i2c_client *newdev;
343 struct device_node *node;
344 bool found_onyx = 0;
345
346 /*
347 * In some cases we end up with the via-pmu node itself, in this
348 * case we skip this function completely as the device-tree will
349 * not contain anything useful.
350 */
351 if (!strcmp(adap->dev.of_node->name, "via-pmu"))
352 return;
353
354 for_each_child_of_node(adap->dev.of_node, node) {
355 struct i2c_board_info info = {};
356 u32 addr;
357
358 /* Get address & channel */
359 addr = i2c_powermac_get_addr(adap, bus, node);
360 if (addr == 0xffffffff)
361 continue;
362
363 /* Multibus setup, check channel */
364 if (!pmac_i2c_match_adapter(node, adap))
365 continue;
366
367 dev_dbg(&adap->dev, "i2c-powermac: register %s\n",
368 node->full_name);
369
370 /*
371 * Keep track of some device existence to handle
372 * workarounds later.
373 */
374 if (of_device_is_compatible(node, "pcm3052"))
375 found_onyx = true;
376
377 /* Make up a modalias */
378 if (!i2c_powermac_get_type(adap, node, addr,
379 info.type, sizeof(info.type))) {
380 continue;
381 }
382
383 /* Fill out the rest of the info structure */
384 info.addr = addr;
385 info.irq = irq_of_parse_and_map(node, 0);
386 info.of_node = of_node_get(node);
387
388 newdev = i2c_new_device(adap, &info);
389 if (!newdev) {
390 dev_err(&adap->dev, "i2c-powermac: Failure to register"
391 " %s\n", node->full_name);
392 of_node_put(node);
393 /* We do not dispose of the interrupt mapping on
394 * purpose. It's not necessary (interrupt cannot be
395 * re-used) and somebody else might have grabbed it
396 * via direct DT lookup so let's not bother
397 */
398 continue;
399 }
400 }
401
402 /* Additional workarounds */
403 i2c_powermac_add_missing(adap, bus, found_onyx);
404}
405
406static int __devinit i2c_powermac_probe(struct platform_device *dev)
407{
408 struct pmac_i2c_bus *bus = dev->dev.platform_data;
409 struct device_node *parent = NULL;
410 struct i2c_adapter *adapter;
411 const char *basename;
412 int rc;
413
414 if (bus == NULL)
415 return -EINVAL;
416 adapter = pmac_i2c_get_adapter(bus);
417
418 /* Ok, now we need to make up a name for the interface that will
419 * match what we used to do in the past, that is basically the
420 * controller's parent device node for keywest. PMU didn't have a
421 * naming convention and SMU has a different one
422 */
423 switch(pmac_i2c_get_type(bus)) {
424 case pmac_i2c_bus_keywest:
425 parent = of_get_parent(pmac_i2c_get_controller(bus));
426 if (parent == NULL)
427 return -EINVAL;
428 basename = parent->name;
429 break;
430 case pmac_i2c_bus_pmu:
431 basename = "pmu";
432 break;
433 case pmac_i2c_bus_smu:
434 /* This is not what we used to do but I'm fixing drivers at
435 * the same time as this change
436 */
437 basename = "smu";
438 break;
439 default:
440 return -EINVAL;
441 }
442 snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
443 pmac_i2c_get_channel(bus));
444 of_node_put(parent);
445
446 platform_set_drvdata(dev, adapter);
447 adapter->algo = &i2c_powermac_algorithm;
448 i2c_set_adapdata(adapter, bus);
449 adapter->dev.parent = &dev->dev;
450 adapter->dev.of_node = dev->dev.of_node;
451 rc = i2c_add_adapter(adapter);
452 if (rc) {
453 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
454 "failed\n", adapter->name);
455 memset(adapter, 0, sizeof(*adapter));
456 }
457
458 printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
459
460 /* Cannot use of_i2c_register_devices() due to Apple device-tree
461 * funkyness
462 */
463 i2c_powermac_register_devices(adapter, bus);
464
465 return rc;
466}
467
468static struct platform_driver i2c_powermac_driver = {
469 .probe = i2c_powermac_probe,
470 .remove = __devexit_p(i2c_powermac_remove),
471 .driver = {
472 .name = "i2c-powermac",
473 .bus = &platform_bus_type,
474 },
475};
476
477module_platform_driver(i2c_powermac_driver);
478
479MODULE_ALIAS("platform:i2c-powermac");