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1 | /* |
2 | * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org> | |
3 | * | |
4 | * Based on drivers/spmi/spmi.c: | |
5 | * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 and | |
9 | * only version 2 as published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <linux/errno.h> | |
18 | #include <linux/idr.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/of.h> | |
22 | #include <linux/of_device.h> | |
23 | #include <linux/serdev.h> | |
24 | #include <linux/slab.h> | |
25 | ||
26 | static bool is_registered; | |
27 | static DEFINE_IDA(ctrl_ida); | |
28 | ||
29 | static void serdev_device_release(struct device *dev) | |
30 | { | |
31 | struct serdev_device *serdev = to_serdev_device(dev); | |
32 | kfree(serdev); | |
33 | } | |
34 | ||
35 | static const struct device_type serdev_device_type = { | |
36 | .release = serdev_device_release, | |
37 | }; | |
38 | ||
39 | static void serdev_ctrl_release(struct device *dev) | |
40 | { | |
41 | struct serdev_controller *ctrl = to_serdev_controller(dev); | |
42 | ida_simple_remove(&ctrl_ida, ctrl->nr); | |
43 | kfree(ctrl); | |
44 | } | |
45 | ||
46 | static const struct device_type serdev_ctrl_type = { | |
47 | .release = serdev_ctrl_release, | |
48 | }; | |
49 | ||
50 | static int serdev_device_match(struct device *dev, struct device_driver *drv) | |
51 | { | |
52 | /* TODO: ACPI and platform matching */ | |
53 | return of_driver_match_device(dev, drv); | |
54 | } | |
55 | ||
56 | static int serdev_uevent(struct device *dev, struct kobj_uevent_env *env) | |
57 | { | |
58 | /* TODO: ACPI and platform modalias */ | |
59 | return of_device_uevent_modalias(dev, env); | |
60 | } | |
61 | ||
62 | /** | |
63 | * serdev_device_add() - add a device previously constructed via serdev_device_alloc() | |
64 | * @serdev: serdev_device to be added | |
65 | */ | |
66 | int serdev_device_add(struct serdev_device *serdev) | |
67 | { | |
68 | struct device *parent = serdev->dev.parent; | |
69 | int err; | |
70 | ||
71 | dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr); | |
72 | ||
73 | err = device_add(&serdev->dev); | |
74 | if (err < 0) { | |
75 | dev_err(&serdev->dev, "Can't add %s, status %d\n", | |
76 | dev_name(&serdev->dev), err); | |
77 | goto err_device_add; | |
78 | } | |
79 | ||
80 | dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev)); | |
81 | ||
82 | err_device_add: | |
83 | return err; | |
84 | } | |
85 | EXPORT_SYMBOL_GPL(serdev_device_add); | |
86 | ||
87 | /** | |
88 | * serdev_device_remove(): remove an serdev device | |
89 | * @serdev: serdev_device to be removed | |
90 | */ | |
91 | void serdev_device_remove(struct serdev_device *serdev) | |
92 | { | |
93 | device_unregister(&serdev->dev); | |
94 | } | |
95 | EXPORT_SYMBOL_GPL(serdev_device_remove); | |
96 | ||
97 | int serdev_device_open(struct serdev_device *serdev) | |
98 | { | |
99 | struct serdev_controller *ctrl = serdev->ctrl; | |
100 | ||
101 | if (!ctrl || !ctrl->ops->open) | |
102 | return -EINVAL; | |
103 | ||
104 | return ctrl->ops->open(ctrl); | |
105 | } | |
106 | EXPORT_SYMBOL_GPL(serdev_device_open); | |
107 | ||
108 | void serdev_device_close(struct serdev_device *serdev) | |
109 | { | |
110 | struct serdev_controller *ctrl = serdev->ctrl; | |
111 | ||
112 | if (!ctrl || !ctrl->ops->close) | |
113 | return; | |
114 | ||
115 | ctrl->ops->close(ctrl); | |
116 | } | |
117 | EXPORT_SYMBOL_GPL(serdev_device_close); | |
118 | ||
119 | int serdev_device_write_buf(struct serdev_device *serdev, | |
120 | const unsigned char *buf, size_t count) | |
121 | { | |
122 | struct serdev_controller *ctrl = serdev->ctrl; | |
123 | ||
124 | if (!ctrl || !ctrl->ops->write_buf) | |
125 | return -EINVAL; | |
126 | ||
127 | return ctrl->ops->write_buf(ctrl, buf, count); | |
128 | } | |
129 | EXPORT_SYMBOL_GPL(serdev_device_write_buf); | |
130 | ||
131 | void serdev_device_write_flush(struct serdev_device *serdev) | |
132 | { | |
133 | struct serdev_controller *ctrl = serdev->ctrl; | |
134 | ||
135 | if (!ctrl || !ctrl->ops->write_flush) | |
136 | return; | |
137 | ||
138 | ctrl->ops->write_flush(ctrl); | |
139 | } | |
140 | EXPORT_SYMBOL_GPL(serdev_device_write_flush); | |
141 | ||
142 | int serdev_device_write_room(struct serdev_device *serdev) | |
143 | { | |
144 | struct serdev_controller *ctrl = serdev->ctrl; | |
145 | ||
146 | if (!ctrl || !ctrl->ops->write_room) | |
147 | return 0; | |
148 | ||
149 | return serdev->ctrl->ops->write_room(ctrl); | |
150 | } | |
151 | EXPORT_SYMBOL_GPL(serdev_device_write_room); | |
152 | ||
153 | unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed) | |
154 | { | |
155 | struct serdev_controller *ctrl = serdev->ctrl; | |
156 | ||
157 | if (!ctrl || !ctrl->ops->set_baudrate) | |
158 | return 0; | |
159 | ||
160 | return ctrl->ops->set_baudrate(ctrl, speed); | |
161 | ||
162 | } | |
163 | EXPORT_SYMBOL_GPL(serdev_device_set_baudrate); | |
164 | ||
165 | void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable) | |
166 | { | |
167 | struct serdev_controller *ctrl = serdev->ctrl; | |
168 | ||
169 | if (!ctrl || !ctrl->ops->set_flow_control) | |
170 | return; | |
171 | ||
172 | ctrl->ops->set_flow_control(ctrl, enable); | |
173 | } | |
174 | EXPORT_SYMBOL_GPL(serdev_device_set_flow_control); | |
175 | ||
176 | static int serdev_drv_probe(struct device *dev) | |
177 | { | |
178 | const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); | |
179 | ||
180 | return sdrv->probe(to_serdev_device(dev)); | |
181 | } | |
182 | ||
183 | static int serdev_drv_remove(struct device *dev) | |
184 | { | |
185 | const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); | |
186 | ||
187 | sdrv->remove(to_serdev_device(dev)); | |
188 | return 0; | |
189 | } | |
190 | ||
191 | static ssize_t modalias_show(struct device *dev, | |
192 | struct device_attribute *attr, char *buf) | |
193 | { | |
194 | ssize_t len = of_device_get_modalias(dev, buf, PAGE_SIZE - 2); | |
195 | buf[len] = '\n'; | |
196 | buf[len+1] = 0; | |
197 | return len+1; | |
198 | } | |
199 | ||
200 | static struct device_attribute serdev_device_attrs[] = { | |
201 | __ATTR_RO(modalias), | |
202 | __ATTR_NULL | |
203 | }; | |
204 | ||
205 | static struct bus_type serdev_bus_type = { | |
206 | .name = "serial", | |
207 | .match = serdev_device_match, | |
208 | .probe = serdev_drv_probe, | |
209 | .remove = serdev_drv_remove, | |
210 | .uevent = serdev_uevent, | |
211 | .dev_attrs = serdev_device_attrs, | |
212 | }; | |
213 | ||
214 | /** | |
215 | * serdev_controller_alloc() - Allocate a new serdev device | |
216 | * @ctrl: associated controller | |
217 | * | |
218 | * Caller is responsible for either calling serdev_device_add() to add the | |
219 | * newly allocated controller, or calling serdev_device_put() to discard it. | |
220 | */ | |
221 | struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) | |
222 | { | |
223 | struct serdev_device *serdev; | |
224 | ||
225 | serdev = kzalloc(sizeof(*serdev), GFP_KERNEL); | |
226 | if (!serdev) | |
227 | return NULL; | |
228 | ||
229 | serdev->ctrl = ctrl; | |
230 | ctrl->serdev = serdev; | |
231 | device_initialize(&serdev->dev); | |
232 | serdev->dev.parent = &ctrl->dev; | |
233 | serdev->dev.bus = &serdev_bus_type; | |
234 | serdev->dev.type = &serdev_device_type; | |
235 | return serdev; | |
236 | } | |
237 | EXPORT_SYMBOL_GPL(serdev_device_alloc); | |
238 | ||
239 | /** | |
240 | * serdev_controller_alloc() - Allocate a new serdev controller | |
241 | * @parent: parent device | |
242 | * @size: size of private data | |
243 | * | |
244 | * Caller is responsible for either calling serdev_controller_add() to add the | |
245 | * newly allocated controller, or calling serdev_controller_put() to discard it. | |
246 | * The allocated private data region may be accessed via | |
247 | * serdev_controller_get_drvdata() | |
248 | */ | |
249 | struct serdev_controller *serdev_controller_alloc(struct device *parent, | |
250 | size_t size) | |
251 | { | |
252 | struct serdev_controller *ctrl; | |
253 | int id; | |
254 | ||
255 | if (WARN_ON(!parent)) | |
256 | return NULL; | |
257 | ||
258 | ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL); | |
259 | if (!ctrl) | |
260 | return NULL; | |
261 | ||
262 | device_initialize(&ctrl->dev); | |
263 | ctrl->dev.type = &serdev_ctrl_type; | |
264 | ctrl->dev.bus = &serdev_bus_type; | |
265 | ctrl->dev.parent = parent; | |
266 | ctrl->dev.of_node = parent->of_node; | |
267 | serdev_controller_set_drvdata(ctrl, &ctrl[1]); | |
268 | ||
269 | id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL); | |
270 | if (id < 0) { | |
271 | dev_err(parent, | |
272 | "unable to allocate serdev controller identifier.\n"); | |
273 | serdev_controller_put(ctrl); | |
274 | return NULL; | |
275 | } | |
276 | ||
277 | ctrl->nr = id; | |
278 | dev_set_name(&ctrl->dev, "serial%d", id); | |
279 | ||
280 | dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id); | |
281 | return ctrl; | |
282 | } | |
283 | EXPORT_SYMBOL_GPL(serdev_controller_alloc); | |
284 | ||
285 | static int of_serdev_register_devices(struct serdev_controller *ctrl) | |
286 | { | |
287 | struct device_node *node; | |
288 | struct serdev_device *serdev = NULL; | |
289 | int err; | |
290 | bool found = false; | |
291 | ||
292 | for_each_available_child_of_node(ctrl->dev.of_node, node) { | |
293 | if (!of_get_property(node, "compatible", NULL)) | |
294 | continue; | |
295 | ||
296 | dev_dbg(&ctrl->dev, "adding child %s\n", node->full_name); | |
297 | ||
298 | serdev = serdev_device_alloc(ctrl); | |
299 | if (!serdev) | |
300 | continue; | |
301 | ||
302 | serdev->dev.of_node = node; | |
303 | ||
304 | err = serdev_device_add(serdev); | |
305 | if (err) { | |
306 | dev_err(&serdev->dev, | |
307 | "failure adding device. status %d\n", err); | |
308 | serdev_device_put(serdev); | |
309 | } else | |
310 | found = true; | |
311 | } | |
312 | if (!found) | |
313 | return -ENODEV; | |
314 | ||
315 | return 0; | |
316 | } | |
317 | ||
318 | /** | |
319 | * serdev_controller_add() - Add an serdev controller | |
320 | * @ctrl: controller to be registered. | |
321 | * | |
322 | * Register a controller previously allocated via serdev_controller_alloc() with | |
323 | * the serdev core. | |
324 | */ | |
325 | int serdev_controller_add(struct serdev_controller *ctrl) | |
326 | { | |
327 | int ret; | |
328 | ||
329 | /* Can't register until after driver model init */ | |
330 | if (WARN_ON(!is_registered)) | |
331 | return -EAGAIN; | |
332 | ||
333 | ret = device_add(&ctrl->dev); | |
334 | if (ret) | |
335 | return ret; | |
336 | ||
337 | ret = of_serdev_register_devices(ctrl); | |
338 | if (ret) | |
339 | goto out_dev_del; | |
340 | ||
341 | dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n", | |
342 | ctrl->nr, &ctrl->dev); | |
343 | return 0; | |
344 | ||
345 | out_dev_del: | |
346 | device_del(&ctrl->dev); | |
347 | return ret; | |
348 | }; | |
349 | EXPORT_SYMBOL_GPL(serdev_controller_add); | |
350 | ||
351 | /* Remove a device associated with a controller */ | |
352 | static int serdev_remove_device(struct device *dev, void *data) | |
353 | { | |
354 | struct serdev_device *serdev = to_serdev_device(dev); | |
355 | if (dev->type == &serdev_device_type) | |
356 | serdev_device_remove(serdev); | |
357 | return 0; | |
358 | } | |
359 | ||
360 | /** | |
361 | * serdev_controller_remove(): remove an serdev controller | |
362 | * @ctrl: controller to remove | |
363 | * | |
364 | * Remove a serdev controller. Caller is responsible for calling | |
365 | * serdev_controller_put() to discard the allocated controller. | |
366 | */ | |
367 | void serdev_controller_remove(struct serdev_controller *ctrl) | |
368 | { | |
369 | int dummy; | |
370 | ||
371 | if (!ctrl) | |
372 | return; | |
373 | ||
374 | dummy = device_for_each_child(&ctrl->dev, NULL, | |
375 | serdev_remove_device); | |
376 | device_del(&ctrl->dev); | |
377 | } | |
378 | EXPORT_SYMBOL_GPL(serdev_controller_remove); | |
379 | ||
380 | /** | |
381 | * serdev_driver_register() - Register client driver with serdev core | |
382 | * @sdrv: client driver to be associated with client-device. | |
383 | * | |
384 | * This API will register the client driver with the serdev framework. | |
385 | * It is typically called from the driver's module-init function. | |
386 | */ | |
387 | int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner) | |
388 | { | |
389 | sdrv->driver.bus = &serdev_bus_type; | |
390 | sdrv->driver.owner = owner; | |
391 | ||
392 | /* force drivers to async probe so I/O is possible in probe */ | |
393 | sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS; | |
394 | ||
395 | return driver_register(&sdrv->driver); | |
396 | } | |
397 | EXPORT_SYMBOL_GPL(__serdev_device_driver_register); | |
398 | ||
399 | static void __exit serdev_exit(void) | |
400 | { | |
401 | bus_unregister(&serdev_bus_type); | |
402 | } | |
403 | module_exit(serdev_exit); | |
404 | ||
405 | static int __init serdev_init(void) | |
406 | { | |
407 | int ret; | |
408 | ||
409 | ret = bus_register(&serdev_bus_type); | |
410 | if (ret) | |
411 | return ret; | |
412 | ||
413 | is_registered = true; | |
414 | return 0; | |
415 | } | |
416 | /* Must be before serial drivers register */ | |
417 | postcore_initcall(serdev_init); | |
418 | ||
419 | MODULE_AUTHOR("Rob Herring <robh@kernel.org>"); | |
420 | MODULE_LICENSE("GPL v2"); | |
421 | MODULE_DESCRIPTION("Serial attached device bus"); |