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 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	kfree(sbdev);
150}
151
152static 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
175static 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
196static 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 */
249int 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}
278EXPORT_SYMBOL_GPL(slim_register_controller);
279
280/* slim_remove_device: Remove the effect of slim_add_device() */
281static void slim_remove_device(struct slim_device *sbdev)
282{
283	of_node_put(sbdev->dev.of_node);
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(struct slim_eaddr *a, struct slim_eaddr *b)
332{
333	return (a->manf_id == b->manf_id &&
334		a->prod_code == b->prod_code &&
335		a->dev_index == b->dev_index &&
336		a->instance == b->instance);
337}
338
339static int slim_match_dev(struct device *dev, void *data)
340{
341	struct slim_eaddr *e_addr = data;
342	struct slim_device *sbdev = to_slim_device(dev);
343
344	return slim_eaddr_equal(&sbdev->e_addr, e_addr);
345}
346
347static struct slim_device *find_slim_device(struct slim_controller *ctrl,
348					    struct slim_eaddr *eaddr)
349{
350	struct slim_device *sbdev;
351	struct device *dev;
352
353	dev = device_find_child(ctrl->dev, eaddr, slim_match_dev);
354	if (dev) {
355		sbdev = to_slim_device(dev);
356		return sbdev;
357	}
358
359	return NULL;
360}
361
362/**
363 * slim_get_device() - get handle to a device.
364 *
365 * @ctrl: Controller on which this device will be added/queried
366 * @e_addr: Enumeration address of the device to be queried
367 *
368 * Return: pointer to a device if it has already reported. Creates a new
369 * device and returns pointer to it if the device has not yet enumerated.
370 */
371struct slim_device *slim_get_device(struct slim_controller *ctrl,
372				    struct slim_eaddr *e_addr)
373{
374	struct slim_device *sbdev;
375
376	sbdev = find_slim_device(ctrl, e_addr);
377	if (!sbdev) {
378		sbdev = slim_alloc_device(ctrl, e_addr, NULL);
379		if (!sbdev)
380			return ERR_PTR(-ENOMEM);
381	}
382
383	return sbdev;
384}
385EXPORT_SYMBOL_GPL(slim_get_device);
386
387static int of_slim_match_dev(struct device *dev, void *data)
388{
389	struct device_node *np = data;
390	struct slim_device *sbdev = to_slim_device(dev);
391
392	return (sbdev->dev.of_node == np);
393}
394
395static struct slim_device *of_find_slim_device(struct slim_controller *ctrl,
396					       struct device_node *np)
397{
398	struct slim_device *sbdev;
399	struct device *dev;
400
401	dev = device_find_child(ctrl->dev, np, of_slim_match_dev);
402	if (dev) {
403		sbdev = to_slim_device(dev);
404		return sbdev;
405	}
406
407	return NULL;
408}
409
410/**
411 * of_slim_get_device() - get handle to a device using dt node.
412 *
413 * @ctrl: Controller on which this device will be added/queried
414 * @np: node pointer to device
415 *
416 * Return: pointer to a device if it has already reported. Creates a new
417 * device and returns pointer to it if the device has not yet enumerated.
418 */
419struct slim_device *of_slim_get_device(struct slim_controller *ctrl,
420				       struct device_node *np)
421{
422	return of_find_slim_device(ctrl, np);
423}
424EXPORT_SYMBOL_GPL(of_slim_get_device);
425
426static int slim_device_alloc_laddr(struct slim_device *sbdev,
427				   bool report_present)
428{
429	struct slim_controller *ctrl = sbdev->ctrl;
430	u8 laddr;
431	int ret;
432
433	mutex_lock(&ctrl->lock);
434	if (ctrl->get_laddr) {
435		ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
436		if (ret < 0)
437			goto err;
438	} else if (report_present) {
439		ret = ida_alloc_max(&ctrl->laddr_ida,
440				    SLIM_LA_MANAGER - 1, GFP_KERNEL);
441		if (ret < 0)
442			goto err;
443
444		laddr = ret;
445	} else {
446		ret = -EINVAL;
447		goto err;
448	}
449
450	if (ctrl->set_laddr) {
451		ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
452		if (ret) {
453			ret = -EINVAL;
454			goto err;
455		}
456	}
457
458	sbdev->laddr = laddr;
459	sbdev->is_laddr_valid = true;
460	mutex_unlock(&ctrl->lock);
461
462	slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
463
464	dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
465		laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
466		sbdev->e_addr.dev_index, sbdev->e_addr.instance);
467
468	return 0;
469
470err:
471	mutex_unlock(&ctrl->lock);
472	return ret;
473
474}
475
476/**
477 * slim_device_report_present() - Report enumerated device.
478 *
479 * @ctrl: Controller with which device is enumerated.
480 * @e_addr: Enumeration address of the device.
481 * @laddr: Return logical address (if valid flag is false)
482 *
483 * Called by controller in response to REPORT_PRESENT. Framework will assign
484 * a logical address to this enumeration address.
485 * Function returns -EXFULL to indicate that all logical addresses are already
486 * taken.
487 */
488int slim_device_report_present(struct slim_controller *ctrl,
489			       struct slim_eaddr *e_addr, u8 *laddr)
490{
491	struct slim_device *sbdev;
492	int ret;
493
494	ret = pm_runtime_get_sync(ctrl->dev);
495
496	if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
497		dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n",
498				    ctrl->sched.clk_state, ret);
499		goto slimbus_not_active;
500	}
501
502	sbdev = slim_get_device(ctrl, e_addr);
503	if (IS_ERR(sbdev))
504		return -ENODEV;
505
506	if (sbdev->is_laddr_valid) {
507		*laddr = sbdev->laddr;
508		return 0;
509	}
510
511	ret = slim_device_alloc_laddr(sbdev, true);
512
513slimbus_not_active:
514	pm_runtime_mark_last_busy(ctrl->dev);
515	pm_runtime_put_autosuspend(ctrl->dev);
516	return ret;
517}
518EXPORT_SYMBOL_GPL(slim_device_report_present);
519
520/**
521 * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
522 *
523 * @sbdev: client handle requesting the address.
524 *
525 * Return: zero if a logical address is valid or a new logical address
526 * has been assigned. error code in case of error.
527 */
528int slim_get_logical_addr(struct slim_device *sbdev)
529{
530	if (!sbdev->is_laddr_valid)
531		return slim_device_alloc_laddr(sbdev, false);
532
533	return 0;
534}
535EXPORT_SYMBOL_GPL(slim_get_logical_addr);
536
537static void __exit slimbus_exit(void)
538{
539	bus_unregister(&slimbus_bus);
540}
541module_exit(slimbus_exit);
542
543static int __init slimbus_init(void)
544{
545	return bus_register(&slimbus_bus);
546}
547postcore_initcall(slimbus_init);
548
549MODULE_LICENSE("GPL v2");
550MODULE_DESCRIPTION("SLIMbus core");
551