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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, 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
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 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
96static 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
103const 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};
110EXPORT_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 */
121int __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}
132EXPORT_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 */
139void slim_driver_unregister(struct slim_driver *drv)
140{
141 driver_unregister(&drv->driver);
142}
143EXPORT_SYMBOL_GPL(slim_driver_unregister);
144
145static void slim_dev_release(struct device *dev)
146{
147 struct slim_device *sbdev = to_slim_device(dev);
148
149 of_node_put(sbdev->dev.of_node);
150 kfree(sbdev);
151}
152
153static int slim_add_device(struct slim_controller *ctrl,
154 struct slim_device *sbdev,
155 struct device_node *node)
156{
157 sbdev->dev.bus = &slimbus_bus;
158 sbdev->dev.parent = ctrl->dev;
159 sbdev->dev.release = slim_dev_release;
160 sbdev->dev.driver = NULL;
161 sbdev->ctrl = ctrl;
162 INIT_LIST_HEAD(&sbdev->stream_list);
163 spin_lock_init(&sbdev->stream_list_lock);
164 sbdev->dev.of_node = of_node_get(node);
165 sbdev->dev.fwnode = of_fwnode_handle(node);
166
167 dev_set_name(&sbdev->dev, "%x:%x:%x:%x",
168 sbdev->e_addr.manf_id,
169 sbdev->e_addr.prod_code,
170 sbdev->e_addr.dev_index,
171 sbdev->e_addr.instance);
172
173 return device_register(&sbdev->dev);
174}
175
176static struct slim_device *slim_alloc_device(struct slim_controller *ctrl,
177 struct slim_eaddr *eaddr,
178 struct device_node *node)
179{
180 struct slim_device *sbdev;
181 int ret;
182
183 sbdev = kzalloc_obj(*sbdev);
184 if (!sbdev)
185 return NULL;
186
187 sbdev->e_addr = *eaddr;
188 ret = slim_add_device(ctrl, sbdev, node);
189 if (ret) {
190 put_device(&sbdev->dev);
191 return NULL;
192 }
193
194 return sbdev;
195}
196
197static void of_register_slim_devices(struct slim_controller *ctrl)
198{
199 struct device *dev = ctrl->dev;
200 struct device_node *node;
201
202 if (!ctrl->dev->of_node)
203 return;
204
205 for_each_child_of_node(ctrl->dev->of_node, node) {
206 struct slim_device *sbdev;
207 struct slim_eaddr e_addr;
208 const char *compat = NULL;
209 int reg[2], ret;
210 int manf_id, prod_code;
211
212 compat = of_get_property(node, "compatible", NULL);
213 if (!compat)
214 continue;
215
216 ret = sscanf(compat, "slim%x,%x", &manf_id, &prod_code);
217 if (ret != 2) {
218 dev_err(dev, "Manf ID & Product code not found %s\n",
219 compat);
220 continue;
221 }
222
223 ret = of_property_read_u32_array(node, "reg", reg, 2);
224 if (ret) {
225 dev_err(dev, "Device and Instance id not found:%d\n",
226 ret);
227 continue;
228 }
229
230 e_addr.dev_index = reg[0];
231 e_addr.instance = reg[1];
232 e_addr.manf_id = manf_id;
233 e_addr.prod_code = prod_code;
234
235 sbdev = slim_alloc_device(ctrl, &e_addr, node);
236 if (!sbdev)
237 continue;
238 }
239}
240
241/*
242 * slim_register_controller() - Controller bring-up and registration.
243 *
244 * @ctrl: Controller to be registered.
245 *
246 * A controller is registered with the framework using this API.
247 * If devices on a controller were registered before controller,
248 * this will make sure that they get probed when controller is up
249 */
250int slim_register_controller(struct slim_controller *ctrl)
251{
252 int id;
253
254 id = ida_alloc(&ctrl_ida, GFP_KERNEL);
255 if (id < 0)
256 return id;
257
258 ctrl->id = id;
259
260 if (!ctrl->min_cg)
261 ctrl->min_cg = SLIM_MIN_CLK_GEAR;
262 if (!ctrl->max_cg)
263 ctrl->max_cg = SLIM_MAX_CLK_GEAR;
264
265 ida_init(&ctrl->laddr_ida);
266 idr_init(&ctrl->tid_idr);
267 mutex_init(&ctrl->lock);
268 mutex_init(&ctrl->sched.m_reconf);
269 init_completion(&ctrl->sched.pause_comp);
270 spin_lock_init(&ctrl->txn_lock);
271
272 dev_dbg(ctrl->dev, "Bus [%s] registered:dev:%p\n",
273 ctrl->name, ctrl->dev);
274
275 of_register_slim_devices(ctrl);
276
277 return 0;
278}
279EXPORT_SYMBOL_GPL(slim_register_controller);
280
281/* slim_remove_device: Remove the effect of slim_add_device() */
282static void slim_remove_device(struct slim_device *sbdev)
283{
284 device_unregister(&sbdev->dev);
285}
286
287static 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 */
298int 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}
306EXPORT_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 */
314void 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}
329EXPORT_SYMBOL_GPL(slim_report_absent);
330
331static 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
340static 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
348static 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 * Takes a reference to the embedded struct device which needs to be dropped
370 * after use.
371 *
372 * Return: pointer to a device if it has already reported. Creates a new
373 * device and returns pointer to it if the device has not yet enumerated.
374 */
375struct slim_device *slim_get_device(struct slim_controller *ctrl,
376 struct slim_eaddr *e_addr)
377{
378 struct slim_device *sbdev;
379
380 sbdev = find_slim_device(ctrl, e_addr);
381 if (!sbdev) {
382 sbdev = slim_alloc_device(ctrl, e_addr, NULL);
383 if (!sbdev)
384 return ERR_PTR(-ENOMEM);
385
386 get_device(&sbdev->dev);
387 }
388
389 return sbdev;
390}
391EXPORT_SYMBOL_GPL(slim_get_device);
392
393/**
394 * of_slim_get_device() - get handle to a device using dt node.
395 *
396 * @ctrl: Controller on which this device will be queried
397 * @np: node pointer to device
398 *
399 * Takes a reference to the embedded struct device which needs to be dropped
400 * after use.
401 *
402 * Return: pointer to a device if it has been registered, otherwise NULL.
403 */
404struct slim_device *of_slim_get_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, device_match_of_node);
411 if (dev) {
412 sbdev = to_slim_device(dev);
413 return sbdev;
414 }
415
416 return NULL;
417}
418EXPORT_SYMBOL_GPL(of_slim_get_device);
419
420static int slim_device_alloc_laddr(struct slim_device *sbdev,
421 bool report_present)
422{
423 struct slim_controller *ctrl = sbdev->ctrl;
424 u8 laddr;
425 int ret;
426
427 mutex_lock(&ctrl->lock);
428 if (ctrl->get_laddr) {
429 ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
430 if (ret < 0)
431 goto err;
432 } else if (report_present) {
433 ret = ida_alloc_max(&ctrl->laddr_ida,
434 SLIM_LA_MANAGER - 1, GFP_KERNEL);
435 if (ret < 0)
436 goto err;
437
438 laddr = ret;
439 } else {
440 ret = -EINVAL;
441 goto err;
442 }
443
444 if (ctrl->set_laddr) {
445 ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
446 if (ret) {
447 ret = -EINVAL;
448 goto err;
449 }
450 }
451
452 sbdev->laddr = laddr;
453 sbdev->is_laddr_valid = true;
454 mutex_unlock(&ctrl->lock);
455
456 slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
457
458 dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
459 laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
460 sbdev->e_addr.dev_index, sbdev->e_addr.instance);
461
462 return 0;
463
464err:
465 mutex_unlock(&ctrl->lock);
466 return ret;
467
468}
469
470/**
471 * slim_device_report_present() - Report enumerated device.
472 *
473 * @ctrl: Controller with which device is enumerated.
474 * @e_addr: Enumeration address of the device.
475 * @laddr: Return logical address (if valid flag is false)
476 *
477 * Called by controller in response to REPORT_PRESENT. Framework will assign
478 * a logical address to this enumeration address.
479 * Function returns -EXFULL to indicate that all logical addresses are already
480 * taken.
481 */
482int slim_device_report_present(struct slim_controller *ctrl,
483 struct slim_eaddr *e_addr, u8 *laddr)
484{
485 struct slim_device *sbdev;
486 int ret;
487
488 ret = pm_runtime_get_sync(ctrl->dev);
489
490 if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
491 dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n",
492 ctrl->sched.clk_state, ret);
493 goto out_put_rpm;
494 }
495
496 sbdev = slim_get_device(ctrl, e_addr);
497 if (IS_ERR(sbdev)) {
498 ret = -ENODEV;
499 goto out_put_rpm;
500 }
501
502 if (sbdev->is_laddr_valid) {
503 *laddr = sbdev->laddr;
504 ret = 0;
505 } else {
506 ret = slim_device_alloc_laddr(sbdev, true);
507 }
508
509 put_device(&sbdev->dev);
510out_put_rpm:
511 pm_runtime_mark_last_busy(ctrl->dev);
512 pm_runtime_put_autosuspend(ctrl->dev);
513 return ret;
514}
515EXPORT_SYMBOL_GPL(slim_device_report_present);
516
517/**
518 * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
519 *
520 * @sbdev: client handle requesting the address.
521 *
522 * Return: zero if a logical address is valid or a new logical address
523 * has been assigned. error code in case of error.
524 */
525int slim_get_logical_addr(struct slim_device *sbdev)
526{
527 if (!sbdev->is_laddr_valid)
528 return slim_device_alloc_laddr(sbdev, false);
529
530 return 0;
531}
532EXPORT_SYMBOL_GPL(slim_get_logical_addr);
533
534static void __exit slimbus_exit(void)
535{
536 bus_unregister(&slimbus_bus);
537}
538module_exit(slimbus_exit);
539
540static int __init slimbus_init(void)
541{
542 return bus_register(&slimbus_bus);
543}
544postcore_initcall(slimbus_init);
545
546MODULE_LICENSE("GPL v2");
547MODULE_DESCRIPTION("SLIMbus core");