005fa2ef100f526df5603d212b6334c06a366c94
[linux-2.6-block.git] / drivers / slimbus / core.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2011-2017, The Linux Foundation
4  */
5
6 #include <linux/kernel.h>
7 #include <linux/errno.h>
8 #include <linux/slab.h>
9 #include <linux/init.h>
10 #include <linux/idr.h>
11 #include <linux/of.h>
12 #include <linux/of_device.h>
13 #include <linux/pm_runtime.h>
14 #include <linux/slimbus.h>
15 #include "slimbus.h"
16
17 static DEFINE_IDA(ctrl_ida);
18
19 static const struct slim_device_id *slim_match(const struct slim_device_id *id,
20                                                const struct slim_device *sbdev)
21 {
22         while (id->manf_id != 0 || id->prod_code != 0) {
23                 if (id->manf_id == sbdev->e_addr.manf_id &&
24                     id->prod_code == sbdev->e_addr.prod_code &&
25                     id->dev_index == sbdev->e_addr.dev_index &&
26                     id->instance == sbdev->e_addr.instance)
27                         return id;
28                 id++;
29         }
30         return NULL;
31 }
32
33 static int slim_device_match(struct device *dev, const struct device_driver *drv)
34 {
35         struct slim_device *sbdev = to_slim_device(dev);
36         const struct slim_driver *sbdrv = to_slim_driver(drv);
37
38         /* Attempt an OF style match first */
39         if (of_driver_match_device(dev, drv))
40                 return 1;
41
42         return !!slim_match(sbdrv->id_table, sbdev);
43 }
44
45 static void slim_device_update_status(struct slim_device *sbdev,
46                                       enum slim_device_status status)
47 {
48         struct slim_driver *sbdrv;
49
50         if (sbdev->status == status)
51                 return;
52
53         sbdev->status = status;
54         if (!sbdev->dev.driver)
55                 return;
56
57         sbdrv = to_slim_driver(sbdev->dev.driver);
58         if (sbdrv->device_status)
59                 sbdrv->device_status(sbdev, sbdev->status);
60 }
61
62 static int slim_device_probe(struct device *dev)
63 {
64         struct slim_device      *sbdev = to_slim_device(dev);
65         struct slim_driver      *sbdrv = to_slim_driver(dev->driver);
66         int ret;
67
68         ret = sbdrv->probe(sbdev);
69         if (ret)
70                 return ret;
71
72         /* try getting the logical address after probe */
73         ret = slim_get_logical_addr(sbdev);
74         if (!ret) {
75                 slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
76         } else {
77                 dev_err(&sbdev->dev, "Failed to get logical address\n");
78                 ret = -EPROBE_DEFER;
79         }
80
81         return ret;
82 }
83
84 static void slim_device_remove(struct device *dev)
85 {
86         struct slim_device *sbdev = to_slim_device(dev);
87         struct slim_driver *sbdrv;
88
89         if (dev->driver) {
90                 sbdrv = to_slim_driver(dev->driver);
91                 if (sbdrv->remove)
92                         sbdrv->remove(sbdev);
93         }
94 }
95
96 static int slim_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
97 {
98         const struct slim_device *sbdev = to_slim_device(dev);
99
100         return add_uevent_var(env, "MODALIAS=slim:%s", dev_name(&sbdev->dev));
101 }
102
103 const struct bus_type slimbus_bus = {
104         .name           = "slimbus",
105         .match          = slim_device_match,
106         .probe          = slim_device_probe,
107         .remove         = slim_device_remove,
108         .uevent         = slim_device_uevent,
109 };
110 EXPORT_SYMBOL_GPL(slimbus_bus);
111
112 /*
113  * __slim_driver_register() - Client driver registration with SLIMbus
114  *
115  * @drv:Client driver to be associated with client-device.
116  * @owner: owning module/driver
117  *
118  * This API will register the client driver with the SLIMbus
119  * It is called from the driver's module-init function.
120  */
121 int __slim_driver_register(struct slim_driver *drv, struct module *owner)
122 {
123         /* ID table and probe are mandatory */
124         if (!(drv->driver.of_match_table || drv->id_table) || !drv->probe)
125                 return -EINVAL;
126
127         drv->driver.bus = &slimbus_bus;
128         drv->driver.owner = owner;
129
130         return driver_register(&drv->driver);
131 }
132 EXPORT_SYMBOL_GPL(__slim_driver_register);
133
134 /*
135  * slim_driver_unregister() - Undo effect of slim_driver_register
136  *
137  * @drv: Client driver to be unregistered
138  */
139 void slim_driver_unregister(struct slim_driver *drv)
140 {
141         driver_unregister(&drv->driver);
142 }
143 EXPORT_SYMBOL_GPL(slim_driver_unregister);
144
145 static void slim_dev_release(struct device *dev)
146 {
147         struct slim_device *sbdev = to_slim_device(dev);
148
149         kfree(sbdev);
150 }
151
152 static int slim_add_device(struct slim_controller *ctrl,
153                            struct slim_device *sbdev,
154                            struct device_node *node)
155 {
156         sbdev->dev.bus = &slimbus_bus;
157         sbdev->dev.parent = ctrl->dev;
158         sbdev->dev.release = slim_dev_release;
159         sbdev->dev.driver = NULL;
160         sbdev->ctrl = ctrl;
161         INIT_LIST_HEAD(&sbdev->stream_list);
162         spin_lock_init(&sbdev->stream_list_lock);
163         sbdev->dev.of_node = of_node_get(node);
164         sbdev->dev.fwnode = of_fwnode_handle(node);
165
166         dev_set_name(&sbdev->dev, "%x:%x:%x:%x",
167                                   sbdev->e_addr.manf_id,
168                                   sbdev->e_addr.prod_code,
169                                   sbdev->e_addr.dev_index,
170                                   sbdev->e_addr.instance);
171
172         return device_register(&sbdev->dev);
173 }
174
175 static struct slim_device *slim_alloc_device(struct slim_controller *ctrl,
176                                              struct slim_eaddr *eaddr,
177                                              struct device_node *node)
178 {
179         struct slim_device *sbdev;
180         int ret;
181
182         sbdev = kzalloc(sizeof(*sbdev), GFP_KERNEL);
183         if (!sbdev)
184                 return NULL;
185
186         sbdev->e_addr = *eaddr;
187         ret = slim_add_device(ctrl, sbdev, node);
188         if (ret) {
189                 put_device(&sbdev->dev);
190                 return NULL;
191         }
192
193         return sbdev;
194 }
195
196 static void of_register_slim_devices(struct slim_controller *ctrl)
197 {
198         struct device *dev = ctrl->dev;
199         struct device_node *node;
200
201         if (!ctrl->dev->of_node)
202                 return;
203
204         for_each_child_of_node(ctrl->dev->of_node, node) {
205                 struct slim_device *sbdev;
206                 struct slim_eaddr e_addr;
207                 const char *compat = NULL;
208                 int reg[2], ret;
209                 int manf_id, prod_code;
210
211                 compat = of_get_property(node, "compatible", NULL);
212                 if (!compat)
213                         continue;
214
215                 ret = sscanf(compat, "slim%x,%x", &manf_id, &prod_code);
216                 if (ret != 2) {
217                         dev_err(dev, "Manf ID & Product code not found %s\n",
218                                 compat);
219                         continue;
220                 }
221
222                 ret = of_property_read_u32_array(node, "reg", reg, 2);
223                 if (ret) {
224                         dev_err(dev, "Device and Instance id not found:%d\n",
225                                 ret);
226                         continue;
227                 }
228
229                 e_addr.dev_index = reg[0];
230                 e_addr.instance = reg[1];
231                 e_addr.manf_id = manf_id;
232                 e_addr.prod_code = prod_code;
233
234                 sbdev = slim_alloc_device(ctrl, &e_addr, node);
235                 if (!sbdev)
236                         continue;
237         }
238 }
239
240 /*
241  * slim_register_controller() - Controller bring-up and registration.
242  *
243  * @ctrl: Controller to be registered.
244  *
245  * A controller is registered with the framework using this API.
246  * If devices on a controller were registered before controller,
247  * this will make sure that they get probed when controller is up
248  */
249 int slim_register_controller(struct slim_controller *ctrl)
250 {
251         int id;
252
253         id = ida_alloc(&ctrl_ida, GFP_KERNEL);
254         if (id < 0)
255                 return id;
256
257         ctrl->id = id;
258
259         if (!ctrl->min_cg)
260                 ctrl->min_cg = SLIM_MIN_CLK_GEAR;
261         if (!ctrl->max_cg)
262                 ctrl->max_cg = SLIM_MAX_CLK_GEAR;
263
264         ida_init(&ctrl->laddr_ida);
265         idr_init(&ctrl->tid_idr);
266         mutex_init(&ctrl->lock);
267         mutex_init(&ctrl->sched.m_reconf);
268         init_completion(&ctrl->sched.pause_comp);
269         spin_lock_init(&ctrl->txn_lock);
270
271         dev_dbg(ctrl->dev, "Bus [%s] registered:dev:%p\n",
272                 ctrl->name, ctrl->dev);
273
274         of_register_slim_devices(ctrl);
275
276         return 0;
277 }
278 EXPORT_SYMBOL_GPL(slim_register_controller);
279
280 /* slim_remove_device: Remove the effect of slim_add_device() */
281 static void slim_remove_device(struct slim_device *sbdev)
282 {
283         of_node_put(sbdev->dev.of_node);
284         device_unregister(&sbdev->dev);
285 }
286
287 static int slim_ctrl_remove_device(struct device *dev, void *null)
288 {
289         slim_remove_device(to_slim_device(dev));
290         return 0;
291 }
292
293 /**
294  * slim_unregister_controller() - Controller tear-down.
295  *
296  * @ctrl: Controller to tear-down.
297  */
298 int slim_unregister_controller(struct slim_controller *ctrl)
299 {
300         /* Remove all clients */
301         device_for_each_child(ctrl->dev, NULL, slim_ctrl_remove_device);
302         ida_free(&ctrl_ida, ctrl->id);
303
304         return 0;
305 }
306 EXPORT_SYMBOL_GPL(slim_unregister_controller);
307
308 /**
309  * slim_report_absent() - Controller calls this function when a device
310  *      reports absent, OR when the device cannot be communicated with
311  *
312  * @sbdev: Device that cannot be reached, or sent report absent
313  */
314 void slim_report_absent(struct slim_device *sbdev)
315 {
316         struct slim_controller *ctrl = sbdev->ctrl;
317
318         if (!ctrl)
319                 return;
320
321         /* invalidate logical addresses */
322         mutex_lock(&ctrl->lock);
323         sbdev->is_laddr_valid = false;
324         mutex_unlock(&ctrl->lock);
325         if (!ctrl->get_laddr)
326                 ida_free(&ctrl->laddr_ida, sbdev->laddr);
327         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN);
328 }
329 EXPORT_SYMBOL_GPL(slim_report_absent);
330
331 static bool slim_eaddr_equal(const struct slim_eaddr *a,
332                              const struct slim_eaddr *b)
333 {
334         return (a->manf_id == b->manf_id &&
335                 a->prod_code == b->prod_code &&
336                 a->dev_index == b->dev_index &&
337                 a->instance == b->instance);
338 }
339
340 static int slim_match_dev(struct device *dev, const void *data)
341 {
342         const struct slim_eaddr *e_addr = data;
343         struct slim_device *sbdev = to_slim_device(dev);
344
345         return slim_eaddr_equal(&sbdev->e_addr, e_addr);
346 }
347
348 static struct slim_device *find_slim_device(struct slim_controller *ctrl,
349                                             struct slim_eaddr *eaddr)
350 {
351         struct slim_device *sbdev;
352         struct device *dev;
353
354         dev = device_find_child(ctrl->dev, eaddr, slim_match_dev);
355         if (dev) {
356                 sbdev = to_slim_device(dev);
357                 return sbdev;
358         }
359
360         return NULL;
361 }
362
363 /**
364  * slim_get_device() - get handle to a device.
365  *
366  * @ctrl: Controller on which this device will be added/queried
367  * @e_addr: Enumeration address of the device to be queried
368  *
369  * Return: pointer to a device if it has already reported. Creates a new
370  * device and returns pointer to it if the device has not yet enumerated.
371  */
372 struct slim_device *slim_get_device(struct slim_controller *ctrl,
373                                     struct slim_eaddr *e_addr)
374 {
375         struct slim_device *sbdev;
376
377         sbdev = find_slim_device(ctrl, e_addr);
378         if (!sbdev) {
379                 sbdev = slim_alloc_device(ctrl, e_addr, NULL);
380                 if (!sbdev)
381                         return ERR_PTR(-ENOMEM);
382         }
383
384         return sbdev;
385 }
386 EXPORT_SYMBOL_GPL(slim_get_device);
387
388 static struct slim_device *of_find_slim_device(struct slim_controller *ctrl,
389                                                struct device_node *np)
390 {
391         struct slim_device *sbdev;
392         struct device *dev;
393
394         dev = device_find_child(ctrl->dev, np, device_match_of_node);
395         if (dev) {
396                 sbdev = to_slim_device(dev);
397                 return sbdev;
398         }
399
400         return NULL;
401 }
402
403 /**
404  * of_slim_get_device() - get handle to a device using dt node.
405  *
406  * @ctrl: Controller on which this device will be added/queried
407  * @np: node pointer to device
408  *
409  * Return: pointer to a device if it has already reported. Creates a new
410  * device and returns pointer to it if the device has not yet enumerated.
411  */
412 struct slim_device *of_slim_get_device(struct slim_controller *ctrl,
413                                        struct device_node *np)
414 {
415         return of_find_slim_device(ctrl, np);
416 }
417 EXPORT_SYMBOL_GPL(of_slim_get_device);
418
419 static int slim_device_alloc_laddr(struct slim_device *sbdev,
420                                    bool report_present)
421 {
422         struct slim_controller *ctrl = sbdev->ctrl;
423         u8 laddr;
424         int ret;
425
426         mutex_lock(&ctrl->lock);
427         if (ctrl->get_laddr) {
428                 ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
429                 if (ret < 0)
430                         goto err;
431         } else if (report_present) {
432                 ret = ida_alloc_max(&ctrl->laddr_ida,
433                                     SLIM_LA_MANAGER - 1, GFP_KERNEL);
434                 if (ret < 0)
435                         goto err;
436
437                 laddr = ret;
438         } else {
439                 ret = -EINVAL;
440                 goto err;
441         }
442
443         if (ctrl->set_laddr) {
444                 ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
445                 if (ret) {
446                         ret = -EINVAL;
447                         goto err;
448                 }
449         }
450
451         sbdev->laddr = laddr;
452         sbdev->is_laddr_valid = true;
453         mutex_unlock(&ctrl->lock);
454
455         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
456
457         dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
458                 laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
459                 sbdev->e_addr.dev_index, sbdev->e_addr.instance);
460
461         return 0;
462
463 err:
464         mutex_unlock(&ctrl->lock);
465         return ret;
466
467 }
468
469 /**
470  * slim_device_report_present() - Report enumerated device.
471  *
472  * @ctrl: Controller with which device is enumerated.
473  * @e_addr: Enumeration address of the device.
474  * @laddr: Return logical address (if valid flag is false)
475  *
476  * Called by controller in response to REPORT_PRESENT. Framework will assign
477  * a logical address to this enumeration address.
478  * Function returns -EXFULL to indicate that all logical addresses are already
479  * taken.
480  */
481 int slim_device_report_present(struct slim_controller *ctrl,
482                                struct slim_eaddr *e_addr, u8 *laddr)
483 {
484         struct slim_device *sbdev;
485         int ret;
486
487         ret = pm_runtime_get_sync(ctrl->dev);
488
489         if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
490                 dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n",
491                                     ctrl->sched.clk_state, ret);
492                 goto slimbus_not_active;
493         }
494
495         sbdev = slim_get_device(ctrl, e_addr);
496         if (IS_ERR(sbdev))
497                 return -ENODEV;
498
499         if (sbdev->is_laddr_valid) {
500                 *laddr = sbdev->laddr;
501                 return 0;
502         }
503
504         ret = slim_device_alloc_laddr(sbdev, true);
505
506 slimbus_not_active:
507         pm_runtime_mark_last_busy(ctrl->dev);
508         pm_runtime_put_autosuspend(ctrl->dev);
509         return ret;
510 }
511 EXPORT_SYMBOL_GPL(slim_device_report_present);
512
513 /**
514  * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
515  *
516  * @sbdev: client handle requesting the address.
517  *
518  * Return: zero if a logical address is valid or a new logical address
519  * has been assigned. error code in case of error.
520  */
521 int slim_get_logical_addr(struct slim_device *sbdev)
522 {
523         if (!sbdev->is_laddr_valid)
524                 return slim_device_alloc_laddr(sbdev, false);
525
526         return 0;
527 }
528 EXPORT_SYMBOL_GPL(slim_get_logical_addr);
529
530 static void __exit slimbus_exit(void)
531 {
532         bus_unregister(&slimbus_bus);
533 }
534 module_exit(slimbus_exit);
535
536 static int __init slimbus_init(void)
537 {
538         return bus_register(&slimbus_bus);
539 }
540 postcore_initcall(slimbus_init);
541
542 MODULE_LICENSE("GPL v2");
543 MODULE_DESCRIPTION("SLIMbus core");