1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
5 * Based on drivers/spmi/spmi.c:
6 * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
9 #include <linux/acpi.h>
10 #include <linux/errno.h>
11 #include <linux/idr.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
15 #include <linux/of_device.h>
16 #include <linux/pm_domain.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/sched.h>
19 #include <linux/serdev.h>
20 #include <linux/slab.h>
22 static bool is_registered;
23 static DEFINE_IDA(ctrl_ida);
25 static ssize_t modalias_show(struct device *dev,
26 struct device_attribute *attr, char *buf)
30 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
34 return of_device_modalias(dev, buf, PAGE_SIZE);
36 static DEVICE_ATTR_RO(modalias);
38 static struct attribute *serdev_device_attrs[] = {
39 &dev_attr_modalias.attr,
42 ATTRIBUTE_GROUPS(serdev_device);
44 static int serdev_device_uevent(struct device *dev, struct kobj_uevent_env *env)
48 /* TODO: platform modalias */
50 rc = acpi_device_uevent_modalias(dev, env);
54 return of_device_uevent_modalias(dev, env);
57 static void serdev_device_release(struct device *dev)
59 struct serdev_device *serdev = to_serdev_device(dev);
63 static const struct device_type serdev_device_type = {
64 .groups = serdev_device_groups,
65 .uevent = serdev_device_uevent,
66 .release = serdev_device_release,
69 static bool is_serdev_device(const struct device *dev)
71 return dev->type == &serdev_device_type;
74 static void serdev_ctrl_release(struct device *dev)
76 struct serdev_controller *ctrl = to_serdev_controller(dev);
77 ida_simple_remove(&ctrl_ida, ctrl->nr);
81 static const struct device_type serdev_ctrl_type = {
82 .release = serdev_ctrl_release,
85 static int serdev_device_match(struct device *dev, struct device_driver *drv)
87 if (!is_serdev_device(dev))
90 /* TODO: platform matching */
91 if (acpi_driver_match_device(dev, drv))
94 return of_driver_match_device(dev, drv);
98 * serdev_device_add() - add a device previously constructed via serdev_device_alloc()
99 * @serdev: serdev_device to be added
101 int serdev_device_add(struct serdev_device *serdev)
103 struct serdev_controller *ctrl = serdev->ctrl;
104 struct device *parent = serdev->dev.parent;
107 dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);
109 /* Only a single slave device is currently supported. */
111 dev_err(&serdev->dev, "controller busy\n");
114 ctrl->serdev = serdev;
116 err = device_add(&serdev->dev);
118 dev_err(&serdev->dev, "Can't add %s, status %d\n",
119 dev_name(&serdev->dev), err);
120 goto err_clear_serdev;
123 dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
131 EXPORT_SYMBOL_GPL(serdev_device_add);
134 * serdev_device_remove(): remove an serdev device
135 * @serdev: serdev_device to be removed
137 void serdev_device_remove(struct serdev_device *serdev)
139 struct serdev_controller *ctrl = serdev->ctrl;
141 device_unregister(&serdev->dev);
144 EXPORT_SYMBOL_GPL(serdev_device_remove);
146 int serdev_device_open(struct serdev_device *serdev)
148 struct serdev_controller *ctrl = serdev->ctrl;
151 if (!ctrl || !ctrl->ops->open)
154 ret = ctrl->ops->open(ctrl);
158 ret = pm_runtime_get_sync(&ctrl->dev);
160 pm_runtime_put_noidle(&ctrl->dev);
167 if (ctrl->ops->close)
168 ctrl->ops->close(ctrl);
172 EXPORT_SYMBOL_GPL(serdev_device_open);
174 void serdev_device_close(struct serdev_device *serdev)
176 struct serdev_controller *ctrl = serdev->ctrl;
178 if (!ctrl || !ctrl->ops->close)
181 pm_runtime_put(&ctrl->dev);
183 ctrl->ops->close(ctrl);
185 EXPORT_SYMBOL_GPL(serdev_device_close);
187 static void devm_serdev_device_release(struct device *dev, void *dr)
189 serdev_device_close(*(struct serdev_device **)dr);
192 int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev)
194 struct serdev_device **dr;
197 dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL);
201 ret = serdev_device_open(serdev);
212 EXPORT_SYMBOL_GPL(devm_serdev_device_open);
214 void serdev_device_write_wakeup(struct serdev_device *serdev)
216 complete(&serdev->write_comp);
218 EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
221 * serdev_device_write_buf() - write data asynchronously
222 * @serdev: serdev device
223 * @buf: data to be written
224 * @count: number of bytes to write
226 * Write data to the device asynchronously.
228 * Note that any accepted data has only been buffered by the controller; use
229 * serdev_device_wait_until_sent() to make sure the controller write buffer
230 * has actually been emptied.
232 * Return: The number of bytes written (less than count if not enough room in
233 * the write buffer), or a negative errno on errors.
235 int serdev_device_write_buf(struct serdev_device *serdev,
236 const unsigned char *buf, size_t count)
238 struct serdev_controller *ctrl = serdev->ctrl;
240 if (!ctrl || !ctrl->ops->write_buf)
243 return ctrl->ops->write_buf(ctrl, buf, count);
245 EXPORT_SYMBOL_GPL(serdev_device_write_buf);
248 * serdev_device_write() - write data synchronously
249 * @serdev: serdev device
250 * @buf: data to be written
251 * @count: number of bytes to write
252 * @timeout: timeout in jiffies, or 0 to wait indefinitely
254 * Write data to the device synchronously by repeatedly calling
255 * serdev_device_write() until the controller has accepted all data (unless
256 * interrupted by a timeout or a signal).
258 * Note that any accepted data has only been buffered by the controller; use
259 * serdev_device_wait_until_sent() to make sure the controller write buffer
260 * has actually been emptied.
262 * Note that this function depends on serdev_device_write_wakeup() being
263 * called in the serdev driver write_wakeup() callback.
265 * Return: The number of bytes written (less than count if interrupted),
266 * -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or
267 * a negative errno on errors.
269 int serdev_device_write(struct serdev_device *serdev,
270 const unsigned char *buf, size_t count,
273 struct serdev_controller *ctrl = serdev->ctrl;
277 if (!ctrl || !ctrl->ops->write_buf || !serdev->ops->write_wakeup)
281 timeout = MAX_SCHEDULE_TIMEOUT;
283 mutex_lock(&serdev->write_lock);
285 reinit_completion(&serdev->write_comp);
287 ret = ctrl->ops->write_buf(ctrl, buf, count);
298 timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp,
300 } while (timeout > 0);
301 mutex_unlock(&serdev->write_lock);
306 if (timeout <= 0 && written == 0) {
307 if (timeout == -ERESTARTSYS)
315 EXPORT_SYMBOL_GPL(serdev_device_write);
317 void serdev_device_write_flush(struct serdev_device *serdev)
319 struct serdev_controller *ctrl = serdev->ctrl;
321 if (!ctrl || !ctrl->ops->write_flush)
324 ctrl->ops->write_flush(ctrl);
326 EXPORT_SYMBOL_GPL(serdev_device_write_flush);
328 int serdev_device_write_room(struct serdev_device *serdev)
330 struct serdev_controller *ctrl = serdev->ctrl;
332 if (!ctrl || !ctrl->ops->write_room)
335 return serdev->ctrl->ops->write_room(ctrl);
337 EXPORT_SYMBOL_GPL(serdev_device_write_room);
339 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
341 struct serdev_controller *ctrl = serdev->ctrl;
343 if (!ctrl || !ctrl->ops->set_baudrate)
346 return ctrl->ops->set_baudrate(ctrl, speed);
349 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);
351 void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
353 struct serdev_controller *ctrl = serdev->ctrl;
355 if (!ctrl || !ctrl->ops->set_flow_control)
358 ctrl->ops->set_flow_control(ctrl, enable);
360 EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);
362 int serdev_device_set_parity(struct serdev_device *serdev,
363 enum serdev_parity parity)
365 struct serdev_controller *ctrl = serdev->ctrl;
367 if (!ctrl || !ctrl->ops->set_parity)
370 return ctrl->ops->set_parity(ctrl, parity);
372 EXPORT_SYMBOL_GPL(serdev_device_set_parity);
374 void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
376 struct serdev_controller *ctrl = serdev->ctrl;
378 if (!ctrl || !ctrl->ops->wait_until_sent)
381 ctrl->ops->wait_until_sent(ctrl, timeout);
383 EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);
385 int serdev_device_get_tiocm(struct serdev_device *serdev)
387 struct serdev_controller *ctrl = serdev->ctrl;
389 if (!ctrl || !ctrl->ops->get_tiocm)
392 return ctrl->ops->get_tiocm(ctrl);
394 EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);
396 int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
398 struct serdev_controller *ctrl = serdev->ctrl;
400 if (!ctrl || !ctrl->ops->set_tiocm)
403 return ctrl->ops->set_tiocm(ctrl, set, clear);
405 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);
407 static int serdev_drv_probe(struct device *dev)
409 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
412 ret = dev_pm_domain_attach(dev, true);
416 ret = sdrv->probe(to_serdev_device(dev));
418 dev_pm_domain_detach(dev, true);
423 static int serdev_drv_remove(struct device *dev)
425 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
427 sdrv->remove(to_serdev_device(dev));
429 dev_pm_domain_detach(dev, true);
434 static struct bus_type serdev_bus_type = {
436 .match = serdev_device_match,
437 .probe = serdev_drv_probe,
438 .remove = serdev_drv_remove,
442 * serdev_device_alloc() - Allocate a new serdev device
443 * @ctrl: associated controller
445 * Caller is responsible for either calling serdev_device_add() to add the
446 * newly allocated controller, or calling serdev_device_put() to discard it.
448 struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl)
450 struct serdev_device *serdev;
452 serdev = kzalloc(sizeof(*serdev), GFP_KERNEL);
457 device_initialize(&serdev->dev);
458 serdev->dev.parent = &ctrl->dev;
459 serdev->dev.bus = &serdev_bus_type;
460 serdev->dev.type = &serdev_device_type;
461 init_completion(&serdev->write_comp);
462 mutex_init(&serdev->write_lock);
465 EXPORT_SYMBOL_GPL(serdev_device_alloc);
468 * serdev_controller_alloc() - Allocate a new serdev controller
469 * @parent: parent device
470 * @size: size of private data
472 * Caller is responsible for either calling serdev_controller_add() to add the
473 * newly allocated controller, or calling serdev_controller_put() to discard it.
474 * The allocated private data region may be accessed via
475 * serdev_controller_get_drvdata()
477 struct serdev_controller *serdev_controller_alloc(struct device *parent,
480 struct serdev_controller *ctrl;
483 if (WARN_ON(!parent))
486 ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
490 id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
493 "unable to allocate serdev controller identifier.\n");
499 device_initialize(&ctrl->dev);
500 ctrl->dev.type = &serdev_ctrl_type;
501 ctrl->dev.bus = &serdev_bus_type;
502 ctrl->dev.parent = parent;
503 ctrl->dev.of_node = parent->of_node;
504 serdev_controller_set_drvdata(ctrl, &ctrl[1]);
506 dev_set_name(&ctrl->dev, "serial%d", id);
508 pm_runtime_no_callbacks(&ctrl->dev);
509 pm_suspend_ignore_children(&ctrl->dev, true);
511 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
519 EXPORT_SYMBOL_GPL(serdev_controller_alloc);
521 static int of_serdev_register_devices(struct serdev_controller *ctrl)
523 struct device_node *node;
524 struct serdev_device *serdev = NULL;
528 for_each_available_child_of_node(ctrl->dev.of_node, node) {
529 if (!of_get_property(node, "compatible", NULL))
532 dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
534 serdev = serdev_device_alloc(ctrl);
538 serdev->dev.of_node = node;
540 err = serdev_device_add(serdev);
542 dev_err(&serdev->dev,
543 "failure adding device. status %d\n", err);
544 serdev_device_put(serdev);
555 static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
556 struct acpi_device *adev)
558 struct serdev_device *serdev = NULL;
561 if (acpi_bus_get_status(adev) || !adev->status.present ||
562 acpi_device_enumerated(adev))
565 serdev = serdev_device_alloc(ctrl);
567 dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
568 dev_name(&adev->dev));
572 ACPI_COMPANION_SET(&serdev->dev, adev);
573 acpi_device_set_enumerated(adev);
575 err = serdev_device_add(serdev);
577 dev_err(&serdev->dev,
578 "failure adding ACPI serdev device. status %d\n", err);
579 serdev_device_put(serdev);
585 static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
586 void *data, void **return_value)
588 struct serdev_controller *ctrl = data;
589 struct acpi_device *adev;
591 if (acpi_bus_get_device(handle, &adev))
594 return acpi_serdev_register_device(ctrl, adev);
597 static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
602 handle = ACPI_HANDLE(ctrl->dev.parent);
606 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
607 acpi_serdev_add_device, NULL, ctrl, NULL);
608 if (ACPI_FAILURE(status))
609 dev_dbg(&ctrl->dev, "failed to enumerate serdev slaves\n");
617 static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
621 #endif /* CONFIG_ACPI */
624 * serdev_controller_add() - Add an serdev controller
625 * @ctrl: controller to be registered.
627 * Register a controller previously allocated via serdev_controller_alloc() with
630 int serdev_controller_add(struct serdev_controller *ctrl)
632 int ret_of, ret_acpi, ret;
634 /* Can't register until after driver model init */
635 if (WARN_ON(!is_registered))
638 ret = device_add(&ctrl->dev);
642 pm_runtime_enable(&ctrl->dev);
644 ret_of = of_serdev_register_devices(ctrl);
645 ret_acpi = acpi_serdev_register_devices(ctrl);
646 if (ret_of && ret_acpi) {
647 dev_dbg(&ctrl->dev, "no devices registered: of:%d acpi:%d\n",
650 goto err_rpm_disable;
653 dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
654 ctrl->nr, &ctrl->dev);
658 pm_runtime_disable(&ctrl->dev);
659 device_del(&ctrl->dev);
662 EXPORT_SYMBOL_GPL(serdev_controller_add);
664 /* Remove a device associated with a controller */
665 static int serdev_remove_device(struct device *dev, void *data)
667 struct serdev_device *serdev = to_serdev_device(dev);
668 if (dev->type == &serdev_device_type)
669 serdev_device_remove(serdev);
674 * serdev_controller_remove(): remove an serdev controller
675 * @ctrl: controller to remove
677 * Remove a serdev controller. Caller is responsible for calling
678 * serdev_controller_put() to discard the allocated controller.
680 void serdev_controller_remove(struct serdev_controller *ctrl)
687 dummy = device_for_each_child(&ctrl->dev, NULL,
688 serdev_remove_device);
689 pm_runtime_disable(&ctrl->dev);
690 device_del(&ctrl->dev);
692 EXPORT_SYMBOL_GPL(serdev_controller_remove);
695 * serdev_driver_register() - Register client driver with serdev core
696 * @sdrv: client driver to be associated with client-device.
698 * This API will register the client driver with the serdev framework.
699 * It is typically called from the driver's module-init function.
701 int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner)
703 sdrv->driver.bus = &serdev_bus_type;
704 sdrv->driver.owner = owner;
706 /* force drivers to async probe so I/O is possible in probe */
707 sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;
709 return driver_register(&sdrv->driver);
711 EXPORT_SYMBOL_GPL(__serdev_device_driver_register);
713 static void __exit serdev_exit(void)
715 bus_unregister(&serdev_bus_type);
716 ida_destroy(&ctrl_ida);
718 module_exit(serdev_exit);
720 static int __init serdev_init(void)
724 ret = bus_register(&serdev_bus_type);
728 is_registered = true;
731 /* Must be before serial drivers register */
732 postcore_initcall(serdev_init);
734 MODULE_AUTHOR("Rob Herring <robh@kernel.org>");
735 MODULE_LICENSE("GPL v2");
736 MODULE_DESCRIPTION("Serial attached device bus");