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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 */
 18 
 19 #include <linux/module.h>
 20 #include <linux/kernel.h>
 21 #include <linux/types.h>
 22 #include <linux/i2c.h>
 23 #include <linux/device.h>
 24 #include <linux/platform_device.h>
 25 #include <linux/of_irq.h>
 26 #include <asm/prom.h>
 27 #include <asm/pmac_low_i2c.h>
 28 
 29 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 30 MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
 31 MODULE_LICENSE("GPL");
 32 
 33 /*
 34  * SMBUS-type transfer entrypoint
 35  */
 36 static s32 i2c_powermac_smbus_xfer(     struct i2c_adapter*     adap,
 37                                         u16                     addr,
 38                                         unsigned short          flags,
 39                                         char                    read_write,
 40                                         u8                      command,
 41                                         int                     size,
 42                                         union i2c_smbus_data*   data)
 43 {
 44         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
 45         int                     rc = 0;
 46         int                     read = (read_write == I2C_SMBUS_READ);
 47         int                     addrdir = (addr << 1) | read;
 48         int                     mode, subsize, len;
 49         u32                     subaddr;
 50         u8                      *buf;
 51         u8                      local[2];
 52 
 53         if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) {
 54                 mode = pmac_i2c_mode_std;
 55                 subsize = 0;
 56                 subaddr = 0;
 57         } else {
 58                 mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub;
 59                 subsize = 1;
 60                 subaddr = command;
 61         }
 62 
 63         switch (size) {
 64         case I2C_SMBUS_QUICK:
 65                 buf = NULL;
 66                 len = 0;
 67                 break;
 68         case I2C_SMBUS_BYTE:
 69         case I2C_SMBUS_BYTE_DATA:
 70                 buf = &data->byte;
 71                 len = 1;
 72                 break;
 73         case I2C_SMBUS_WORD_DATA:
 74                 if (!read) {
 75                         local[0] = data->word & 0xff;
 76                         local[1] = (data->word >> 8) & 0xff;
 77                 }
 78                 buf = local;
 79                 len = 2;
 80                 break;
 81 
 82         /* Note that these are broken vs. the expected smbus API where
 83          * on reads, the length is actually returned from the function,
 84          * but I think the current API makes no sense and I don't want
 85          * any driver that I haven't verified for correctness to go
 86          * anywhere near a pmac i2c bus anyway ...
 87          *
 88          * I'm also not completely sure what kind of phases to do between
 89          * the actual command and the data (what I am _supposed_ to do that
 90          * is). For now, I assume writes are a single stream and reads have
 91          * a repeat start/addr phase (but not stop in between)
 92          */
 93         case I2C_SMBUS_BLOCK_DATA:
 94                 buf = data->block;
 95                 len = data->block[0] + 1;
 96                 break;
 97         case I2C_SMBUS_I2C_BLOCK_DATA:
 98                 buf = &data->block[1];
 99                 len = data->block[0];
100                 break;
101 
102         default:
103                 return -EINVAL;
104         }
105 
106         rc = pmac_i2c_open(bus, 0);
107         if (rc) {
108                 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
109                 return rc;
110         }
111 
112         rc = pmac_i2c_setmode(bus, mode);
113         if (rc) {
114                 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
115                         mode, rc);
116                 goto bail;
117         }
118 
119         rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len);
120         if (rc) {
121                 if (rc == -ENXIO)
122                         dev_dbg(&adap->dev,
123                                 "I2C transfer at 0x%02x failed, size %d, "
124                                 "err %d\n", addrdir >> 1, size, rc);
125                 else
126                         dev_err(&adap->dev,
127                                 "I2C transfer at 0x%02x failed, size %d, "
128                                 "err %d\n", addrdir >> 1, size, rc);
129                 goto bail;
130         }
131 
132         if (size == I2C_SMBUS_WORD_DATA && read) {
133                 data->word = ((u16)local[1]) << 8;
134                 data->word |= local[0];
135         }
136 
137  bail:
138         pmac_i2c_close(bus);
139         return rc;
140 }
141 
142 /*
143  * Generic i2c master transfer entrypoint. This driver only support single
144  * messages (for "lame i2c" transfers). Anything else should use the smbus
145  * entry point
146  */
147 static int i2c_powermac_master_xfer(    struct i2c_adapter *adap,
148                                         struct i2c_msg *msgs,
149                                         int num)
150 {
151         struct pmac_i2c_bus     *bus = i2c_get_adapdata(adap);
152         int                     rc = 0;
153         int                     addrdir;
154 
155         if (msgs->flags & I2C_M_TEN)
156                 return -EINVAL;
157         addrdir = i2c_8bit_addr_from_msg(msgs);
158 
159         rc = pmac_i2c_open(bus, 0);
160         if (rc) {
161                 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
162                 return rc;
163         }
164         rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
165         if (rc) {
166                 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
167                         pmac_i2c_mode_std, rc);
168                 goto bail;
169         }
170         rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
171         if (rc < 0) {
172                 if (rc == -ENXIO)
173                         dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
174                                 addrdir & 1 ? "read from" : "write to",
175                                 addrdir >> 1, rc);
176                 else
177                         dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
178                                 addrdir & 1 ? "read from" : "write to",
179                                 addrdir >> 1, rc);
180         }
181  bail:
182         pmac_i2c_close(bus);
183         return rc < 0 ? rc : 1;
184 }
185 
186 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
187 {
188         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
189                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
190                 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
191 }
192 
193 /* For now, we only handle smbus */
194 static const struct i2c_algorithm i2c_powermac_algorithm = {
195         .smbus_xfer     = i2c_powermac_smbus_xfer,
196         .master_xfer    = i2c_powermac_master_xfer,
197         .functionality  = i2c_powermac_func,
198 };
199 
200 static struct i2c_adapter_quirks i2c_powermac_quirks = {
201         .max_num_msgs = 1,
202 };
203 
204 static int i2c_powermac_remove(struct platform_device *dev)
205 {
206         struct i2c_adapter      *adapter = platform_get_drvdata(dev);
207 
208         i2c_del_adapter(adapter);
209         memset(adapter, 0, sizeof(*adapter));
210 
211         return 0;
212 }
213 
214 static u32 i2c_powermac_get_addr(struct i2c_adapter *adap,
215                                            struct pmac_i2c_bus *bus,
216                                            struct device_node *node)
217 {
218         const __be32 *prop;
219         int len;
220 
221         /* First check for valid "reg" */
222         prop = of_get_property(node, "reg", &len);
223         if (prop && (len >= sizeof(int)))
224                 return (be32_to_cpup(prop) & 0xff) >> 1;
225 
226         /* Then check old-style "i2c-address" */
227         prop = of_get_property(node, "i2c-address", &len);
228         if (prop && (len >= sizeof(int)))
229                 return (be32_to_cpup(prop) & 0xff) >> 1;
230 
231         /* Now handle some devices with missing "reg" properties */
232         if (!strcmp(node->name, "cereal"))
233                 return 0x60;
234         else if (!strcmp(node->name, "deq"))
235                 return 0x34;
236 
237         dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name);
238 
239         return 0xffffffff;
240 }
241 
242 static void i2c_powermac_create_one(struct i2c_adapter *adap,
243                                               const char *type,
244                                               u32 addr)
245 {
246         struct i2c_board_info info = {};
247         struct i2c_client *newdev;
248 
249         strncpy(info.type, type, sizeof(info.type));
250         info.addr = addr;
251         newdev = i2c_new_device(adap, &info);
252         if (!newdev)
253                 dev_err(&adap->dev,
254                         "i2c-powermac: Failure to register missing %s\n",
255                         type);
256 }
257 
258 static void i2c_powermac_add_missing(struct i2c_adapter *adap,
259                                                struct pmac_i2c_bus *bus,
260                                                bool found_onyx)
261 {
262         struct device_node *busnode = pmac_i2c_get_bus_node(bus);
263         int rc;
264 
265         /* Check for the onyx audio codec */
266 #define ONYX_REG_CONTROL                67
267         if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
268                 union i2c_smbus_data data;
269 
270                 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
271                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
272                                     &data);
273                 if (rc >= 0)
274                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
275 
276                 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
277                                     ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
278                                     &data);
279                 if (rc >= 0)
280                         i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
281         }
282 }
283 
284 static bool i2c_powermac_get_type(struct i2c_adapter *adap,
285                                             struct device_node *node,
286                                             u32 addr, char *type, int type_size)
287 {
288         char tmp[16];
289 
290         /* Note: we to _NOT_ want the standard
291          * i2c drivers to match with any of our powermac stuff
292          * unless they have been specifically modified to handle
293          * it on a case by case basis. For example, for thermal
294          * control, things like lm75 etc... shall match with their
295          * corresponding windfarm drivers, _NOT_ the generic ones,
296          * so we force a prefix of AAPL, onto the modalias to
297          * make that happen
298          */
299 
300         /* First try proper modalias */
301         if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
302                 snprintf(type, type_size, "MAC,%s", tmp);
303                 return true;
304         }
305 
306         /* Now look for known workarounds */
307         if (!strcmp(node->name, "deq")) {
308                 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
309                 if (addr == 0x34) {
310                         snprintf(type, type_size, "MAC,tas3001");
311                         return true;
312                 } else if (addr == 0x35) {
313                         snprintf(type, type_size, "MAC,tas3004");
314                         return true;
315                 }
316         }
317 
318         dev_err(&adap->dev, "i2c-powermac: modalias failure"
319                 " on %s\n", node->full_name);
320         return false;
321 }
322 
323 static void i2c_powermac_register_devices(struct i2c_adapter *adap,
324                                                     struct pmac_i2c_bus *bus)
325 {
326         struct i2c_client *newdev;
327         struct device_node *node;
328         bool found_onyx = 0;
329 
330         /*
331          * In some cases we end up with the via-pmu node itself, in this
332          * case we skip this function completely as the device-tree will
333          * not contain anything useful.
334          */
335         if (!strcmp(adap->dev.of_node->name, "via-pmu"))
336                 return;
337 
338         for_each_child_of_node(adap->dev.of_node, node) {
339                 struct i2c_board_info info = {};
340                 u32 addr;
341 
342                 /* Get address & channel */
343                 addr = i2c_powermac_get_addr(adap, bus, node);
344                 if (addr == 0xffffffff)
345                         continue;
346 
347                 /* Multibus setup, check channel */
348                 if (!pmac_i2c_match_adapter(node, adap))
349                         continue;
350 
351                 dev_dbg(&adap->dev, "i2c-powermac: register %s\n",
352                         node->full_name);
353 
354                 /*
355                  * Keep track of some device existence to handle
356                  * workarounds later.
357                  */
358                 if (of_device_is_compatible(node, "pcm3052"))
359                         found_onyx = true;
360 
361                 /* Make up a modalias */
362                 if (!i2c_powermac_get_type(adap, node, addr,
363                                            info.type, sizeof(info.type))) {
364                         continue;
365                 }
366 
367                 /* Fill out the rest of the info structure */
368                 info.addr = addr;
369                 info.irq = irq_of_parse_and_map(node, 0);
370                 info.of_node = of_node_get(node);
371 
372                 newdev = i2c_new_device(adap, &info);
373                 if (!newdev) {
374                         dev_err(&adap->dev, "i2c-powermac: Failure to register"
375                                 " %s\n", node->full_name);
376                         of_node_put(node);
377                         /* We do not dispose of the interrupt mapping on
378                          * purpose. It's not necessary (interrupt cannot be
379                          * re-used) and somebody else might have grabbed it
380                          * via direct DT lookup so let's not bother
381                          */
382                         continue;
383                 }
384         }
385 
386         /* Additional workarounds */
387         i2c_powermac_add_missing(adap, bus, found_onyx);
388 }
389 
390 static int i2c_powermac_probe(struct platform_device *dev)
391 {
392         struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev);
393         struct device_node *parent = NULL;
394         struct i2c_adapter *adapter;
395         const char *basename;
396         int rc;
397 
398         if (bus == NULL)
399                 return -EINVAL;
400         adapter = pmac_i2c_get_adapter(bus);
401 
402         /* Ok, now we need to make up a name for the interface that will
403          * match what we used to do in the past, that is basically the
404          * controller's parent device node for keywest. PMU didn't have a
405          * naming convention and SMU has a different one
406          */
407         switch(pmac_i2c_get_type(bus)) {
408         case pmac_i2c_bus_keywest:
409                 parent = of_get_parent(pmac_i2c_get_controller(bus));
410                 if (parent == NULL)
411                         return -EINVAL;
412                 basename = parent->name;
413                 break;
414         case pmac_i2c_bus_pmu:
415                 basename = "pmu";
416                 break;
417         case pmac_i2c_bus_smu:
418                 /* This is not what we used to do but I'm fixing drivers at
419                  * the same time as this change
420                  */
421                 basename = "smu";
422                 break;
423         default:
424                 return -EINVAL;
425         }
426         snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
427                  pmac_i2c_get_channel(bus));
428         of_node_put(parent);
429 
430         platform_set_drvdata(dev, adapter);
431         adapter->algo = &i2c_powermac_algorithm;
432         adapter->quirks = &i2c_powermac_quirks;
433         i2c_set_adapdata(adapter, bus);
434         adapter->dev.parent = &dev->dev;
435 
436         /* Clear of_node to skip automatic registration of i2c child nodes */
437         adapter->dev.of_node = NULL;
438         rc = i2c_add_adapter(adapter);
439         if (rc) {
440                 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
441                        "failed\n", adapter->name);
442                 memset(adapter, 0, sizeof(*adapter));
443                 return rc;
444         }
445 
446         printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
447 
448         /* Use custom child registration due to Apple device-tree funkyness */
449         adapter->dev.of_node = dev->dev.of_node;
450         i2c_powermac_register_devices(adapter, bus);
451 
452         return 0;
453 }
454 
455 static struct platform_driver i2c_powermac_driver = {
456         .probe = i2c_powermac_probe,
457         .remove = i2c_powermac_remove,
458         .driver = {
459                 .name = "i2c-powermac",
460                 .bus = &platform_bus_type,
461         },
462 };
463 
464 module_platform_driver(i2c_powermac_driver);
465 
466 MODULE_ALIAS("platform:i2c-powermac");
467 

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