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(id: 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, status: 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, format: "MODALIAS=slim:%s", dev_name(dev: &sbdev->dev));
101}
102
103struct 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: &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: &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(objp: 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(list: &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(dev: &sbdev->dev, name: "%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(dev: &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(size: 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(dev: &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, name: "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(np: node, propname: "reg", out_values: reg, sz: 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, eaddr: &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(ida: &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(ida: &ctrl->laddr_ida);
265 idr_init(idr: &ctrl->tid_idr);
266 mutex_init(&ctrl->lock);
267 mutex_init(&ctrl->sched.m_reconf);
268 init_completion(x: &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(node: sbdev->dev.of_node);
284 device_unregister(dev: &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(dev: ctrl->dev, NULL, fn: slim_ctrl_remove_device);
302 ida_free(&ctrl_ida, id: 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(lock: &ctrl->lock);
325 if (!ctrl->get_laddr)
326 ida_free(&ctrl->laddr_ida, id: sbdev->laddr);
327 slim_device_update_status(sbdev, status: 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(a: &sbdev->e_addr, b: 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(dev: ctrl->dev, data: eaddr, match: 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, eaddr: e_addr);
377 if (!sbdev) {
378 sbdev = slim_alloc_device(ctrl, eaddr: e_addr, NULL);
379 if (!sbdev)
380 return ERR_PTR(error: -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(dev: ctrl->dev, data: np, match: 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_simple_get(&ctrl->laddr_ida,
440 0, 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(lock: &ctrl->lock);
461
462 slim_device_update_status(sbdev, status: 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(lock: &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(dev: 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(ptr: 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, report_present: true);
512
513slimbus_not_active:
514 pm_runtime_mark_last_busy(dev: ctrl->dev);
515 pm_runtime_put_autosuspend(dev: 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, report_present: false);
532
533 return 0;
534}
535EXPORT_SYMBOL_GPL(slim_get_logical_addr);
536
537static void __exit slimbus_exit(void)
538{
539 bus_unregister(bus: &slimbus_bus);
540}
541module_exit(slimbus_exit);
542
543static int __init slimbus_init(void)
544{
545 return bus_register(bus: &slimbus_bus);
546}
547postcore_initcall(slimbus_init);
548
549MODULE_LICENSE("GPL v2");
550MODULE_DESCRIPTION("SLIMbus core");
551

source code of linux/drivers/slimbus/core.c