Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

Linux/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/device.h>
 28 #include <linux/platform_device.h>
 29 #include <linux/of_irq.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         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  */
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 
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 
213 static int i2c_powermac_remove(struct platform_device *dev)
214 {
215         struct i2c_adapter      *adapter = platform_get_drvdata(dev);
216 
217         i2c_del_adapter(adapter);
218         memset(adapter, 0, sizeof(*adapter));
219 
220         return 0;
221 }
222 
223 static u32 i2c_powermac_get_addr(struct i2c_adapter *adap,
224                                            struct pmac_i2c_bus *bus,
225                                            struct device_node *node)
226 {
227         const __be32 *prop;
228         int len;
229 
230         /* First check for valid "reg" */
231         prop = of_get_property(node, "reg", &len);
232         if (prop && (len >= sizeof(int)))
233                 return (be32_to_cpup(prop) & 0xff) >> 1;
234 
235         /* Then check old-style "i2c-address" */
236         prop = of_get_property(node, "i2c-address", &len);
237         if (prop && (len >= sizeof(int)))
238                 return (be32_to_cpup(prop) & 0xff) >> 1;
239 
240         /* Now handle some devices with missing "reg" properties */
241         if (!strcmp(node->name, "cereal"))
242                 return 0x60;
243         else if (!strcmp(node->name, "deq"))
244                 return 0x34;
245 
246         dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name);
247 
248         return 0xffffffff;
249 }
250 
251 static void i2c_powermac_create_one(struct i2c_adapter *adap,
252                                               const char *type,
253                                               u32 addr)
254 {
255         struct i2c_board_info info = {};
256         struct i2c_client *newdev;
257 
258         strncpy(info.type, type, sizeof(info.type));
259         info.addr = addr;
260         newdev = i2c_new_device(adap, &info);
261         if (!newdev)
262                 dev_err(&adap->dev,
263                         "i2c-powermac: Failure to register missing %s\n",
264                         type);
265 }
266 
267 static void i2c_powermac_add_missing(struct i2c_adapter *adap,
268                                                struct pmac_i2c_bus *bus,
269                                                bool found_onyx)
270 {
271         struct device_node *busnode = pmac_i2c_get_bus_node(bus);
272         int rc;
273 
274         /* Check for the onyx audio codec */
275 #define ONYX_REG_CONTROL                67
276         if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
277                 union i2c_smbus_data data;
278 
279                 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
280                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
281                                     &data);
282                 if (rc >= 0)
283                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
284 
285                 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
286                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
287                                     &data);
288                 if (rc >= 0)
289                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
290         }
291 }
292 
293 static bool i2c_powermac_get_type(struct i2c_adapter *adap,
294                                             struct device_node *node,
295                                             u32 addr, char *type, int type_size)
296 {
297         char tmp[16];
298 
299         /* Note: we to _NOT_ want the standard
300          * i2c drivers to match with any of our powermac stuff
301          * unless they have been specifically modified to handle
302          * it on a case by case basis. For example, for thermal
303          * control, things like lm75 etc... shall match with their
304          * corresponding windfarm drivers, _NOT_ the generic ones,
305          * so we force a prefix of AAPL, onto the modalias to
306          * make that happen
307          */
308 
309         /* First try proper modalias */
310         if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
311                 snprintf(type, type_size, "MAC,%s", tmp);
312                 return true;
313         }
314 
315         /* Now look for known workarounds */
316         if (!strcmp(node->name, "deq")) {
317                 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
318                 if (addr == 0x34) {
319                         snprintf(type, type_size, "MAC,tas3001");
320                         return true;
321                 } else if (addr == 0x35) {
322                         snprintf(type, type_size, "MAC,tas3004");
323                         return true;
324                 }
325         }
326 
327         dev_err(&adap->dev, "i2c-powermac: modalias failure"
328                 " on %s\n", node->full_name);
329         return false;
330 }
331 
332 static void i2c_powermac_register_devices(struct i2c_adapter *adap,
333                                                     struct pmac_i2c_bus *bus)
334 {
335         struct i2c_client *newdev;
336         struct device_node *node;
337         bool found_onyx = 0;
338 
339         /*
340          * In some cases we end up with the via-pmu node itself, in this
341          * case we skip this function completely as the device-tree will
342          * not contain anything useful.
343          */
344         if (!strcmp(adap->dev.of_node->name, "via-pmu"))
345                 return;
346 
347         for_each_child_of_node(adap->dev.of_node, node) {
348                 struct i2c_board_info info = {};
349                 u32 addr;
350 
351                 /* Get address & channel */
352                 addr = i2c_powermac_get_addr(adap, bus, node);
353                 if (addr == 0xffffffff)
354                         continue;
355 
356                 /* Multibus setup, check channel */
357                 if (!pmac_i2c_match_adapter(node, adap))
358                         continue;
359 
360                 dev_dbg(&adap->dev, "i2c-powermac: register %s\n",
361                         node->full_name);
362 
363                 /*
364                  * Keep track of some device existence to handle
365                  * workarounds later.
366                  */
367                 if (of_device_is_compatible(node, "pcm3052"))
368                         found_onyx = true;
369 
370                 /* Make up a modalias */
371                 if (!i2c_powermac_get_type(adap, node, addr,
372                                            info.type, sizeof(info.type))) {
373                         continue;
374                 }
375 
376                 /* Fill out the rest of the info structure */
377                 info.addr = addr;
378                 info.irq = irq_of_parse_and_map(node, 0);
379                 info.of_node = of_node_get(node);
380 
381                 newdev = i2c_new_device(adap, &info);
382                 if (!newdev) {
383                         dev_err(&adap->dev, "i2c-powermac: Failure to register"
384                                 " %s\n", node->full_name);
385                         of_node_put(node);
386                         /* We do not dispose of the interrupt mapping on
387                          * purpose. It's not necessary (interrupt cannot be
388                          * re-used) and somebody else might have grabbed it
389                          * via direct DT lookup so let's not bother
390                          */
391                         continue;
392                 }
393         }
394 
395         /* Additional workarounds */
396         i2c_powermac_add_missing(adap, bus, found_onyx);
397 }
398 
399 static int i2c_powermac_probe(struct platform_device *dev)
400 {
401         struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev);
402         struct device_node *parent = NULL;
403         struct i2c_adapter *adapter;
404         const char *basename;
405         int rc;
406 
407         if (bus == NULL)
408                 return -EINVAL;
409         adapter = pmac_i2c_get_adapter(bus);
410 
411         /* Ok, now we need to make up a name for the interface that will
412          * match what we used to do in the past, that is basically the
413          * controller's parent device node for keywest. PMU didn't have a
414          * naming convention and SMU has a different one
415          */
416         switch(pmac_i2c_get_type(bus)) {
417         case pmac_i2c_bus_keywest:
418                 parent = of_get_parent(pmac_i2c_get_controller(bus));
419                 if (parent == NULL)
420                         return -EINVAL;
421                 basename = parent->name;
422                 break;
423         case pmac_i2c_bus_pmu:
424                 basename = "pmu";
425                 break;
426         case pmac_i2c_bus_smu:
427                 /* This is not what we used to do but I'm fixing drivers at
428                  * the same time as this change
429                  */
430                 basename = "smu";
431                 break;
432         default:
433                 return -EINVAL;
434         }
435         snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
436                  pmac_i2c_get_channel(bus));
437         of_node_put(parent);
438 
439         platform_set_drvdata(dev, adapter);
440         adapter->algo = &i2c_powermac_algorithm;
441         i2c_set_adapdata(adapter, bus);
442         adapter->dev.parent = &dev->dev;
443 
444         /* Clear of_node to skip automatic registration of i2c child nodes */
445         adapter->dev.of_node = NULL;
446         rc = i2c_add_adapter(adapter);
447         if (rc) {
448                 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
449                        "failed\n", adapter->name);
450                 memset(adapter, 0, sizeof(*adapter));
451                 return rc;
452         }
453 
454         printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
455 
456         /* Use custom child registration due to Apple device-tree funkyness */
457         adapter->dev.of_node = dev->dev.of_node;
458         i2c_powermac_register_devices(adapter, bus);
459 
460         return 0;
461 }
462 
463 static struct platform_driver i2c_powermac_driver = {
464         .probe = i2c_powermac_probe,
465         .remove = i2c_powermac_remove,
466         .driver = {
467                 .name = "i2c-powermac",
468                 .bus = &platform_bus_type,
469         },
470 };
471 
472 module_platform_driver(i2c_powermac_driver);
473 
474 MODULE_ALIAS("platform:i2c-powermac");
475 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us