1 | /* |
2 | * MEN Chameleon Bus. |
3 | * |
4 | * Copyright (C) 2013 MEN Mikroelektronik GmbH (www.men.de) |
5 | * Author: Johannes Thumshirn <johannes.thumshirn@men.de> |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify it |
8 | * under the terms of the GNU General Public License as published by the Free |
9 | * Software Foundation; version 2 of the License. |
10 | */ |
11 | #include <linux/kernel.h> |
12 | #include <linux/module.h> |
13 | #include <linux/slab.h> |
14 | #include <linux/types.h> |
15 | #include <linux/idr.h> |
16 | #include <linux/mcb.h> |
17 | |
18 | static DEFINE_IDA(mcb_ida); |
19 | |
20 | static const struct mcb_device_id *mcb_match_id(const struct mcb_device_id *ids, |
21 | struct mcb_device *dev) |
22 | { |
23 | if (ids) { |
24 | while (ids->device) { |
25 | if (ids->device == dev->id) |
26 | return ids; |
27 | ids++; |
28 | } |
29 | } |
30 | |
31 | return NULL; |
32 | } |
33 | |
34 | static int mcb_match(struct device *dev, struct device_driver *drv) |
35 | { |
36 | struct mcb_driver *mdrv = to_mcb_driver(drv); |
37 | struct mcb_device *mdev = to_mcb_device(dev); |
38 | const struct mcb_device_id *found_id; |
39 | |
40 | found_id = mcb_match_id(mdrv->id_table, mdev); |
41 | if (found_id) |
42 | return 1; |
43 | |
44 | return 0; |
45 | } |
46 | |
47 | static int mcb_uevent(struct device *dev, struct kobj_uevent_env *env) |
48 | { |
49 | struct mcb_device *mdev = to_mcb_device(dev); |
50 | int ret; |
51 | |
52 | ret = add_uevent_var(env, "MODALIAS=mcb:16z%03d" , mdev->id); |
53 | if (ret) |
54 | return -ENOMEM; |
55 | |
56 | return 0; |
57 | } |
58 | |
59 | static int mcb_probe(struct device *dev) |
60 | { |
61 | struct mcb_driver *mdrv = to_mcb_driver(dev->driver); |
62 | struct mcb_device *mdev = to_mcb_device(dev); |
63 | const struct mcb_device_id *found_id; |
64 | struct module *carrier_mod; |
65 | int ret; |
66 | |
67 | found_id = mcb_match_id(mdrv->id_table, mdev); |
68 | if (!found_id) |
69 | return -ENODEV; |
70 | |
71 | carrier_mod = mdev->dev.parent->driver->owner; |
72 | if (!try_module_get(carrier_mod)) |
73 | return -EINVAL; |
74 | |
75 | get_device(dev); |
76 | ret = mdrv->probe(mdev, found_id); |
77 | if (ret) |
78 | module_put(carrier_mod); |
79 | |
80 | return ret; |
81 | } |
82 | |
83 | static int mcb_remove(struct device *dev) |
84 | { |
85 | struct mcb_driver *mdrv = to_mcb_driver(dev->driver); |
86 | struct mcb_device *mdev = to_mcb_device(dev); |
87 | struct module *carrier_mod; |
88 | |
89 | mdrv->remove(mdev); |
90 | |
91 | carrier_mod = mdev->dev.parent->driver->owner; |
92 | module_put(carrier_mod); |
93 | |
94 | put_device(&mdev->dev); |
95 | |
96 | return 0; |
97 | } |
98 | |
99 | static void mcb_shutdown(struct device *dev) |
100 | { |
101 | struct mcb_driver *mdrv = to_mcb_driver(dev->driver); |
102 | struct mcb_device *mdev = to_mcb_device(dev); |
103 | |
104 | if (mdrv && mdrv->shutdown) |
105 | mdrv->shutdown(mdev); |
106 | } |
107 | |
108 | static ssize_t revision_show(struct device *dev, struct device_attribute *attr, |
109 | char *buf) |
110 | { |
111 | struct mcb_bus *bus = to_mcb_bus(dev); |
112 | |
113 | return scnprintf(buf, PAGE_SIZE, "%d\n" , bus->revision); |
114 | } |
115 | static DEVICE_ATTR_RO(revision); |
116 | |
117 | static ssize_t model_show(struct device *dev, struct device_attribute *attr, |
118 | char *buf) |
119 | { |
120 | struct mcb_bus *bus = to_mcb_bus(dev); |
121 | |
122 | return scnprintf(buf, PAGE_SIZE, "%c\n" , bus->model); |
123 | } |
124 | static DEVICE_ATTR_RO(model); |
125 | |
126 | static ssize_t minor_show(struct device *dev, struct device_attribute *attr, |
127 | char *buf) |
128 | { |
129 | struct mcb_bus *bus = to_mcb_bus(dev); |
130 | |
131 | return scnprintf(buf, PAGE_SIZE, "%d\n" , bus->minor); |
132 | } |
133 | static DEVICE_ATTR_RO(minor); |
134 | |
135 | static ssize_t name_show(struct device *dev, struct device_attribute *attr, |
136 | char *buf) |
137 | { |
138 | struct mcb_bus *bus = to_mcb_bus(dev); |
139 | |
140 | return scnprintf(buf, PAGE_SIZE, "%s\n" , bus->name); |
141 | } |
142 | static DEVICE_ATTR_RO(name); |
143 | |
144 | static struct attribute *mcb_bus_attrs[] = { |
145 | &dev_attr_revision.attr, |
146 | &dev_attr_model.attr, |
147 | &dev_attr_minor.attr, |
148 | &dev_attr_name.attr, |
149 | NULL, |
150 | }; |
151 | |
152 | static const struct attribute_group mcb_carrier_group = { |
153 | .attrs = mcb_bus_attrs, |
154 | }; |
155 | |
156 | static const struct attribute_group *mcb_carrier_groups[] = { |
157 | &mcb_carrier_group, |
158 | NULL, |
159 | }; |
160 | |
161 | |
162 | static struct bus_type mcb_bus_type = { |
163 | .name = "mcb" , |
164 | .match = mcb_match, |
165 | .uevent = mcb_uevent, |
166 | .probe = mcb_probe, |
167 | .remove = mcb_remove, |
168 | .shutdown = mcb_shutdown, |
169 | }; |
170 | |
171 | static struct device_type mcb_carrier_device_type = { |
172 | .name = "mcb-carrier" , |
173 | .groups = mcb_carrier_groups, |
174 | }; |
175 | |
176 | /** |
177 | * __mcb_register_driver() - Register a @mcb_driver at the system |
178 | * @drv: The @mcb_driver |
179 | * @owner: The @mcb_driver's module |
180 | * @mod_name: The name of the @mcb_driver's module |
181 | * |
182 | * Register a @mcb_driver at the system. Perform some sanity checks, if |
183 | * the .probe and .remove methods are provided by the driver. |
184 | */ |
185 | int __mcb_register_driver(struct mcb_driver *drv, struct module *owner, |
186 | const char *mod_name) |
187 | { |
188 | if (!drv->probe || !drv->remove) |
189 | return -EINVAL; |
190 | |
191 | drv->driver.owner = owner; |
192 | drv->driver.bus = &mcb_bus_type; |
193 | drv->driver.mod_name = mod_name; |
194 | |
195 | return driver_register(&drv->driver); |
196 | } |
197 | EXPORT_SYMBOL_GPL(__mcb_register_driver); |
198 | |
199 | /** |
200 | * mcb_unregister_driver() - Unregister a @mcb_driver from the system |
201 | * @drv: The @mcb_driver |
202 | * |
203 | * Unregister a @mcb_driver from the system. |
204 | */ |
205 | void mcb_unregister_driver(struct mcb_driver *drv) |
206 | { |
207 | driver_unregister(&drv->driver); |
208 | } |
209 | EXPORT_SYMBOL_GPL(mcb_unregister_driver); |
210 | |
211 | static void mcb_release_dev(struct device *dev) |
212 | { |
213 | struct mcb_device *mdev = to_mcb_device(dev); |
214 | |
215 | mcb_bus_put(mdev->bus); |
216 | kfree(mdev); |
217 | } |
218 | |
219 | /** |
220 | * mcb_device_register() - Register a mcb_device |
221 | * @bus: The @mcb_bus of the device |
222 | * @dev: The @mcb_device |
223 | * |
224 | * Register a specific @mcb_device at a @mcb_bus and the system itself. |
225 | */ |
226 | int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev) |
227 | { |
228 | int ret; |
229 | int device_id; |
230 | |
231 | device_initialize(&dev->dev); |
232 | mcb_bus_get(bus); |
233 | dev->dev.bus = &mcb_bus_type; |
234 | dev->dev.parent = bus->dev.parent; |
235 | dev->dev.release = mcb_release_dev; |
236 | dev->dma_dev = bus->carrier; |
237 | |
238 | device_id = dev->id; |
239 | dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d" , |
240 | bus->bus_nr, device_id, dev->inst, dev->group, dev->var); |
241 | |
242 | ret = device_add(&dev->dev); |
243 | if (ret < 0) { |
244 | pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n" , |
245 | device_id, bus->bus_nr, ret); |
246 | goto out; |
247 | } |
248 | |
249 | return 0; |
250 | |
251 | out: |
252 | |
253 | return ret; |
254 | } |
255 | EXPORT_SYMBOL_GPL(mcb_device_register); |
256 | |
257 | static void mcb_free_bus(struct device *dev) |
258 | { |
259 | struct mcb_bus *bus = to_mcb_bus(dev); |
260 | |
261 | put_device(bus->carrier); |
262 | ida_simple_remove(&mcb_ida, bus->bus_nr); |
263 | kfree(bus); |
264 | } |
265 | |
266 | /** |
267 | * mcb_alloc_bus() - Allocate a new @mcb_bus |
268 | * |
269 | * Allocate a new @mcb_bus. |
270 | */ |
271 | struct mcb_bus *mcb_alloc_bus(struct device *carrier) |
272 | { |
273 | struct mcb_bus *bus; |
274 | int bus_nr; |
275 | int rc; |
276 | |
277 | bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL); |
278 | if (!bus) |
279 | return ERR_PTR(-ENOMEM); |
280 | |
281 | bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL); |
282 | if (bus_nr < 0) { |
283 | rc = bus_nr; |
284 | goto err_free; |
285 | } |
286 | |
287 | bus->bus_nr = bus_nr; |
288 | bus->carrier = get_device(carrier); |
289 | |
290 | device_initialize(&bus->dev); |
291 | bus->dev.parent = carrier; |
292 | bus->dev.bus = &mcb_bus_type; |
293 | bus->dev.type = &mcb_carrier_device_type; |
294 | bus->dev.release = &mcb_free_bus; |
295 | |
296 | dev_set_name(&bus->dev, "mcb:%d" , bus_nr); |
297 | rc = device_add(&bus->dev); |
298 | if (rc) |
299 | goto err_free; |
300 | |
301 | return bus; |
302 | err_free: |
303 | put_device(carrier); |
304 | kfree(bus); |
305 | return ERR_PTR(rc); |
306 | } |
307 | EXPORT_SYMBOL_GPL(mcb_alloc_bus); |
308 | |
309 | static int __mcb_devices_unregister(struct device *dev, void *data) |
310 | { |
311 | device_unregister(dev); |
312 | return 0; |
313 | } |
314 | |
315 | static void mcb_devices_unregister(struct mcb_bus *bus) |
316 | { |
317 | bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister); |
318 | } |
319 | /** |
320 | * mcb_release_bus() - Free a @mcb_bus |
321 | * @bus: The @mcb_bus to release |
322 | * |
323 | * Release an allocated @mcb_bus from the system. |
324 | */ |
325 | void mcb_release_bus(struct mcb_bus *bus) |
326 | { |
327 | mcb_devices_unregister(bus); |
328 | } |
329 | EXPORT_SYMBOL_GPL(mcb_release_bus); |
330 | |
331 | /** |
332 | * mcb_bus_put() - Increment refcnt |
333 | * @bus: The @mcb_bus |
334 | * |
335 | * Get a @mcb_bus' ref |
336 | */ |
337 | struct mcb_bus *mcb_bus_get(struct mcb_bus *bus) |
338 | { |
339 | if (bus) |
340 | get_device(&bus->dev); |
341 | |
342 | return bus; |
343 | } |
344 | EXPORT_SYMBOL_GPL(mcb_bus_get); |
345 | |
346 | /** |
347 | * mcb_bus_put() - Decrement refcnt |
348 | * @bus: The @mcb_bus |
349 | * |
350 | * Release a @mcb_bus' ref |
351 | */ |
352 | void mcb_bus_put(struct mcb_bus *bus) |
353 | { |
354 | if (bus) |
355 | put_device(&bus->dev); |
356 | } |
357 | EXPORT_SYMBOL_GPL(mcb_bus_put); |
358 | |
359 | /** |
360 | * mcb_alloc_dev() - Allocate a device |
361 | * @bus: The @mcb_bus the device is part of |
362 | * |
363 | * Allocate a @mcb_device and add bus. |
364 | */ |
365 | struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus) |
366 | { |
367 | struct mcb_device *dev; |
368 | |
369 | dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL); |
370 | if (!dev) |
371 | return NULL; |
372 | |
373 | dev->bus = bus; |
374 | |
375 | return dev; |
376 | } |
377 | EXPORT_SYMBOL_GPL(mcb_alloc_dev); |
378 | |
379 | /** |
380 | * mcb_free_dev() - Free @mcb_device |
381 | * @dev: The device to free |
382 | * |
383 | * Free a @mcb_device |
384 | */ |
385 | void mcb_free_dev(struct mcb_device *dev) |
386 | { |
387 | kfree(dev); |
388 | } |
389 | EXPORT_SYMBOL_GPL(mcb_free_dev); |
390 | |
391 | static int __mcb_bus_add_devices(struct device *dev, void *data) |
392 | { |
393 | struct mcb_device *mdev = to_mcb_device(dev); |
394 | int retval; |
395 | |
396 | if (mdev->is_added) |
397 | return 0; |
398 | |
399 | retval = device_attach(dev); |
400 | if (retval < 0) |
401 | dev_err(dev, "Error adding device (%d)\n" , retval); |
402 | |
403 | mdev->is_added = true; |
404 | |
405 | return 0; |
406 | } |
407 | |
408 | /** |
409 | * mcb_bus_add_devices() - Add devices in the bus' internal device list |
410 | * @bus: The @mcb_bus we add the devices |
411 | * |
412 | * Add devices in the bus' internal device list to the system. |
413 | */ |
414 | void mcb_bus_add_devices(const struct mcb_bus *bus) |
415 | { |
416 | bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_devices); |
417 | } |
418 | EXPORT_SYMBOL_GPL(mcb_bus_add_devices); |
419 | |
420 | /** |
421 | * mcb_get_resource() - get a resource for a mcb device |
422 | * @dev: the mcb device |
423 | * @type: the type of resource |
424 | */ |
425 | struct resource *mcb_get_resource(struct mcb_device *dev, unsigned int type) |
426 | { |
427 | if (type == IORESOURCE_MEM) |
428 | return &dev->mem; |
429 | else if (type == IORESOURCE_IRQ) |
430 | return &dev->irq; |
431 | else |
432 | return NULL; |
433 | } |
434 | EXPORT_SYMBOL_GPL(mcb_get_resource); |
435 | |
436 | /** |
437 | * mcb_request_mem() - Request memory |
438 | * @dev: The @mcb_device the memory is for |
439 | * @name: The name for the memory reference. |
440 | * |
441 | * Request memory for a @mcb_device. If @name is NULL the driver name will |
442 | * be used. |
443 | */ |
444 | struct resource *mcb_request_mem(struct mcb_device *dev, const char *name) |
445 | { |
446 | struct resource *mem; |
447 | u32 size; |
448 | |
449 | if (!name) |
450 | name = dev->dev.driver->name; |
451 | |
452 | size = resource_size(&dev->mem); |
453 | |
454 | mem = request_mem_region(dev->mem.start, size, name); |
455 | if (!mem) |
456 | return ERR_PTR(-EBUSY); |
457 | |
458 | return mem; |
459 | } |
460 | EXPORT_SYMBOL_GPL(mcb_request_mem); |
461 | |
462 | /** |
463 | * mcb_release_mem() - Release memory requested by device |
464 | * @dev: The @mcb_device that requested the memory |
465 | * |
466 | * Release memory that was prior requested via @mcb_request_mem(). |
467 | */ |
468 | void mcb_release_mem(struct resource *mem) |
469 | { |
470 | u32 size; |
471 | |
472 | size = resource_size(mem); |
473 | release_mem_region(mem->start, size); |
474 | } |
475 | EXPORT_SYMBOL_GPL(mcb_release_mem); |
476 | |
477 | static int __mcb_get_irq(struct mcb_device *dev) |
478 | { |
479 | struct resource *irq; |
480 | |
481 | irq = mcb_get_resource(dev, IORESOURCE_IRQ); |
482 | |
483 | return irq->start; |
484 | } |
485 | |
486 | /** |
487 | * mcb_get_irq() - Get device's IRQ number |
488 | * @dev: The @mcb_device the IRQ is for |
489 | * |
490 | * Get the IRQ number of a given @mcb_device. |
491 | */ |
492 | int mcb_get_irq(struct mcb_device *dev) |
493 | { |
494 | struct mcb_bus *bus = dev->bus; |
495 | |
496 | if (bus->get_irq) |
497 | return bus->get_irq(dev); |
498 | |
499 | return __mcb_get_irq(dev); |
500 | } |
501 | EXPORT_SYMBOL_GPL(mcb_get_irq); |
502 | |
503 | static int mcb_init(void) |
504 | { |
505 | return bus_register(&mcb_bus_type); |
506 | } |
507 | |
508 | static void mcb_exit(void) |
509 | { |
510 | ida_destroy(&mcb_ida); |
511 | bus_unregister(&mcb_bus_type); |
512 | } |
513 | |
514 | /* mcb must be initialized after PCI but before the chameleon drivers. |
515 | * That means we must use some initcall between subsys_initcall and |
516 | * device_initcall. |
517 | */ |
518 | fs_initcall(mcb_init); |
519 | module_exit(mcb_exit); |
520 | |
521 | MODULE_DESCRIPTION("MEN Chameleon Bus Driver" ); |
522 | MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>" ); |
523 | MODULE_LICENSE("GPL v2" ); |
524 | |