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
17static DEFINE_IDA(ctrl_ida);
18
19static 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
33static int slim_device_match(struct device *dev, struct device_driver *drv)
34{
35 struct slim_device *sbdev = to_slim_device(dev);
36 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
45static 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
62static 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
84static int 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 return 0;
96}
97
98static int slim_device_uevent(struct device *dev, struct kobj_uevent_env *env)
99{
100 struct slim_device *sbdev = to_slim_device(dev);
101 int ret;
102
103 ret = of_device_uevent_modalias(dev, env);
104 if (ret != -ENODEV)
105 return ret;
106
107 return add_uevent_var(env, "MODALIAS=slim:%s", dev_name(&sbdev->dev));
108}
109
110struct bus_type slimbus_bus = {
111 .name = "slimbus",
112 .match = slim_device_match,
113 .probe = slim_device_probe,
114 .remove = slim_device_remove,
115 .uevent = slim_device_uevent,
116};
117EXPORT_SYMBOL_GPL(slimbus_bus);
118
119/*
120 * __slim_driver_register() - Client driver registration with SLIMbus
121 *
122 * @drv:Client driver to be associated with client-device.
123 * @owner: owning module/driver
124 *
125 * This API will register the client driver with the SLIMbus
126 * It is called from the driver's module-init function.
127 */
128int __slim_driver_register(struct slim_driver *drv, struct module *owner)
129{
130 /* ID table and probe are mandatory */
131 if (!(drv->driver.of_match_table || drv->id_table) || !drv->probe)
132 return -EINVAL;
133
134 drv->driver.bus = &slimbus_bus;
135 drv->driver.owner = owner;
136
137 return driver_register(&drv->driver);
138}
139EXPORT_SYMBOL_GPL(__slim_driver_register);
140
141/*
142 * slim_driver_unregister() - Undo effect of slim_driver_register
143 *
144 * @drv: Client driver to be unregistered
145 */
146void slim_driver_unregister(struct slim_driver *drv)
147{
148 driver_unregister(&drv->driver);
149}
150EXPORT_SYMBOL_GPL(slim_driver_unregister);
151
152static void slim_dev_release(struct device *dev)
153{
154 struct slim_device *sbdev = to_slim_device(dev);
155
156 kfree(sbdev);
157}
158
159static int slim_add_device(struct slim_controller *ctrl,
160 struct slim_device *sbdev,
161 struct device_node *node)
162{
163 sbdev->dev.bus = &slimbus_bus;
164 sbdev->dev.parent = ctrl->dev;
165 sbdev->dev.release = slim_dev_release;
166 sbdev->dev.driver = NULL;
167 sbdev->ctrl = ctrl;
168 INIT_LIST_HEAD(&sbdev->stream_list);
169 spin_lock_init(&sbdev->stream_list_lock);
170
171 if (node)
172 sbdev->dev.of_node = of_node_get(node);
173
174 dev_set_name(&sbdev->dev, "%x:%x:%x:%x",
175 sbdev->e_addr.manf_id,
176 sbdev->e_addr.prod_code,
177 sbdev->e_addr.dev_index,
178 sbdev->e_addr.instance);
179
180 return device_register(&sbdev->dev);
181}
182
183static struct slim_device *slim_alloc_device(struct slim_controller *ctrl,
184 struct slim_eaddr *eaddr,
185 struct device_node *node)
186{
187 struct slim_device *sbdev;
188 int ret;
189
190 sbdev = kzalloc(sizeof(*sbdev), GFP_KERNEL);
191 if (!sbdev)
192 return NULL;
193
194 sbdev->e_addr = *eaddr;
195 ret = slim_add_device(ctrl, sbdev, node);
196 if (ret) {
197 put_device(&sbdev->dev);
198 return NULL;
199 }
200
201 return sbdev;
202}
203
204static void of_register_slim_devices(struct slim_controller *ctrl)
205{
206 struct device *dev = ctrl->dev;
207 struct device_node *node;
208
209 if (!ctrl->dev->of_node)
210 return;
211
212 for_each_child_of_node(ctrl->dev->of_node, node) {
213 struct slim_device *sbdev;
214 struct slim_eaddr e_addr;
215 const char *compat = NULL;
216 int reg[2], ret;
217 int manf_id, prod_code;
218
219 compat = of_get_property(node, "compatible", NULL);
220 if (!compat)
221 continue;
222
223 ret = sscanf(compat, "slim%x,%x", &manf_id, &prod_code);
224 if (ret != 2) {
225 dev_err(dev, "Manf ID & Product code not found %s\n",
226 compat);
227 continue;
228 }
229
230 ret = of_property_read_u32_array(node, "reg", reg, 2);
231 if (ret) {
232 dev_err(dev, "Device and Instance id not found:%d\n",
233 ret);
234 continue;
235 }
236
237 e_addr.dev_index = reg[0];
238 e_addr.instance = reg[1];
239 e_addr.manf_id = manf_id;
240 e_addr.prod_code = prod_code;
241
242 sbdev = slim_alloc_device(ctrl, &e_addr, node);
243 if (!sbdev)
244 continue;
245 }
246}
247
248/*
249 * slim_register_controller() - Controller bring-up and registration.
250 *
251 * @ctrl: Controller to be registered.
252 *
253 * A controller is registered with the framework using this API.
254 * If devices on a controller were registered before controller,
255 * this will make sure that they get probed when controller is up
256 */
257int slim_register_controller(struct slim_controller *ctrl)
258{
259 int id;
260
261 id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
262 if (id < 0)
263 return id;
264
265 ctrl->id = id;
266
267 if (!ctrl->min_cg)
268 ctrl->min_cg = SLIM_MIN_CLK_GEAR;
269 if (!ctrl->max_cg)
270 ctrl->max_cg = SLIM_MAX_CLK_GEAR;
271
272 ida_init(&ctrl->laddr_ida);
273 idr_init(&ctrl->tid_idr);
274 mutex_init(&ctrl->lock);
275 mutex_init(&ctrl->sched.m_reconf);
276 init_completion(&ctrl->sched.pause_comp);
277 spin_lock_init(&ctrl->txn_lock);
278
279 dev_dbg(ctrl->dev, "Bus [%s] registered:dev:%p\n",
280 ctrl->name, ctrl->dev);
281
282 of_register_slim_devices(ctrl);
283
284 return 0;
285}
286EXPORT_SYMBOL_GPL(slim_register_controller);
287
288/* slim_remove_device: Remove the effect of slim_add_device() */
289static void slim_remove_device(struct slim_device *sbdev)
290{
291 device_unregister(&sbdev->dev);
292}
293
294static int slim_ctrl_remove_device(struct device *dev, void *null)
295{
296 slim_remove_device(to_slim_device(dev));
297 return 0;
298}
299
300/**
301 * slim_unregister_controller() - Controller tear-down.
302 *
303 * @ctrl: Controller to tear-down.
304 */
305int slim_unregister_controller(struct slim_controller *ctrl)
306{
307 /* Remove all clients */
308 device_for_each_child(ctrl->dev, NULL, slim_ctrl_remove_device);
309 /* Enter Clock Pause */
310 slim_ctrl_clk_pause(ctrl, false, 0);
311 ida_simple_remove(&ctrl_ida, ctrl->id);
312
313 return 0;
314}
315EXPORT_SYMBOL_GPL(slim_unregister_controller);
316
317/**
318 * slim_report_absent() - Controller calls this function when a device
319 * reports absent, OR when the device cannot be communicated with
320 *
321 * @sbdev: Device that cannot be reached, or sent report absent
322 */
323void slim_report_absent(struct slim_device *sbdev)
324{
325 struct slim_controller *ctrl = sbdev->ctrl;
326
327 if (!ctrl)
328 return;
329
330 /* invalidate logical addresses */
331 mutex_lock(&ctrl->lock);
332 sbdev->is_laddr_valid = false;
333 mutex_unlock(&ctrl->lock);
334
335 ida_simple_remove(&ctrl->laddr_ida, sbdev->laddr);
336 slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN);
337}
338EXPORT_SYMBOL_GPL(slim_report_absent);
339
340static bool slim_eaddr_equal(struct slim_eaddr *a, struct slim_eaddr *b)
341{
342 return (a->manf_id == b->manf_id &&
343 a->prod_code == b->prod_code &&
344 a->dev_index == b->dev_index &&
345 a->instance == b->instance);
346}
347
348static int slim_match_dev(struct device *dev, void *data)
349{
350 struct slim_eaddr *e_addr = data;
351 struct slim_device *sbdev = to_slim_device(dev);
352
353 return slim_eaddr_equal(&sbdev->e_addr, e_addr);
354}
355
356static struct slim_device *find_slim_device(struct slim_controller *ctrl,
357 struct slim_eaddr *eaddr)
358{
359 struct slim_device *sbdev;
360 struct device *dev;
361
362 dev = device_find_child(ctrl->dev, eaddr, slim_match_dev);
363 if (dev) {
364 sbdev = to_slim_device(dev);
365 return sbdev;
366 }
367
368 return NULL;
369}
370
371/**
372 * slim_get_device() - get handle to a device.
373 *
374 * @ctrl: Controller on which this device will be added/queried
375 * @e_addr: Enumeration address of the device to be queried
376 *
377 * Return: pointer to a device if it has already reported. Creates a new
378 * device and returns pointer to it if the device has not yet enumerated.
379 */
380struct slim_device *slim_get_device(struct slim_controller *ctrl,
381 struct slim_eaddr *e_addr)
382{
383 struct slim_device *sbdev;
384
385 sbdev = find_slim_device(ctrl, e_addr);
386 if (!sbdev) {
387 sbdev = slim_alloc_device(ctrl, e_addr, NULL);
388 if (!sbdev)
389 return ERR_PTR(-ENOMEM);
390 }
391
392 return sbdev;
393}
394EXPORT_SYMBOL_GPL(slim_get_device);
395
396static int of_slim_match_dev(struct device *dev, void *data)
397{
398 struct device_node *np = data;
399 struct slim_device *sbdev = to_slim_device(dev);
400
401 return (sbdev->dev.of_node == np);
402}
403
404static struct slim_device *of_find_slim_device(struct slim_controller *ctrl,
405 struct device_node *np)
406{
407 struct slim_device *sbdev;
408 struct device *dev;
409
410 dev = device_find_child(ctrl->dev, np, of_slim_match_dev);
411 if (dev) {
412 sbdev = to_slim_device(dev);
413 return sbdev;
414 }
415
416 return NULL;
417}
418
419/**
420 * of_slim_get_device() - get handle to a device using dt node.
421 *
422 * @ctrl: Controller on which this device will be added/queried
423 * @np: node pointer to device
424 *
425 * Return: pointer to a device if it has already reported. Creates a new
426 * device and returns pointer to it if the device has not yet enumerated.
427 */
428struct slim_device *of_slim_get_device(struct slim_controller *ctrl,
429 struct device_node *np)
430{
431 return of_find_slim_device(ctrl, np);
432}
433EXPORT_SYMBOL_GPL(of_slim_get_device);
434
435static int slim_device_alloc_laddr(struct slim_device *sbdev,
436 bool report_present)
437{
438 struct slim_controller *ctrl = sbdev->ctrl;
439 u8 laddr;
440 int ret;
441
442 mutex_lock(&ctrl->lock);
443 if (ctrl->get_laddr) {
444 ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
445 if (ret < 0)
446 goto err;
447 } else if (report_present) {
448 ret = ida_simple_get(&ctrl->laddr_ida,
449 0, SLIM_LA_MANAGER - 1, GFP_KERNEL);
450 if (ret < 0)
451 goto err;
452
453 laddr = ret;
454 } else {
455 ret = -EINVAL;
456 goto err;
457 }
458
459 if (ctrl->set_laddr) {
460 ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
461 if (ret) {
462 ret = -EINVAL;
463 goto err;
464 }
465 }
466
467 sbdev->laddr = laddr;
468 sbdev->is_laddr_valid = true;
469 mutex_unlock(&ctrl->lock);
470
471 slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
472
473 dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
474 laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
475 sbdev->e_addr.dev_index, sbdev->e_addr.instance);
476
477 return 0;
478
479err:
480 mutex_unlock(&ctrl->lock);
481 return ret;
482
483}
484
485/**
486 * slim_device_report_present() - Report enumerated device.
487 *
488 * @ctrl: Controller with which device is enumerated.
489 * @e_addr: Enumeration address of the device.
490 * @laddr: Return logical address (if valid flag is false)
491 *
492 * Called by controller in response to REPORT_PRESENT. Framework will assign
493 * a logical address to this enumeration address.
494 * Function returns -EXFULL to indicate that all logical addresses are already
495 * taken.
496 */
497int slim_device_report_present(struct slim_controller *ctrl,
498 struct slim_eaddr *e_addr, u8 *laddr)
499{
500 struct slim_device *sbdev;
501 int ret;
502
503 ret = pm_runtime_get_sync(ctrl->dev);
504
505 if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
506 dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n",
507 ctrl->sched.clk_state, ret);
508 goto slimbus_not_active;
509 }
510
511 sbdev = slim_get_device(ctrl, e_addr);
512 if (IS_ERR(sbdev))
513 return -ENODEV;
514
515 if (sbdev->is_laddr_valid) {
516 *laddr = sbdev->laddr;
517 return 0;
518 }
519
520 ret = slim_device_alloc_laddr(sbdev, true);
521
522slimbus_not_active:
523 pm_runtime_mark_last_busy(ctrl->dev);
524 pm_runtime_put_autosuspend(ctrl->dev);
525 return ret;
526}
527EXPORT_SYMBOL_GPL(slim_device_report_present);
528
529/**
530 * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
531 *
532 * @sbdev: client handle requesting the address.
533 *
534 * Return: zero if a logical address is valid or a new logical address
535 * has been assigned. error code in case of error.
536 */
537int slim_get_logical_addr(struct slim_device *sbdev)
538{
539 if (!sbdev->is_laddr_valid)
540 return slim_device_alloc_laddr(sbdev, false);
541
542 return 0;
543}
544EXPORT_SYMBOL_GPL(slim_get_logical_addr);
545
546static void __exit slimbus_exit(void)
547{
548 bus_unregister(&slimbus_bus);
549}
550module_exit(slimbus_exit);
551
552static int __init slimbus_init(void)
553{
554 return bus_register(&slimbus_bus);
555}
556postcore_initcall(slimbus_init);
557
558MODULE_LICENSE("GPL v2");
559MODULE_DESCRIPTION("SLIMbus core");
560