[linux-2.6-block.git] / drivers / tty / serdev / core.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
 *
 * Based on drivers/spmi/spmi.c:
 * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
 */

#include <linux/acpi.h>
#include <linux/errno.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/serdev.h>
#include <linux/slab.h>

static bool is_registered;
static DEFINE_IDA(ctrl_ida);

static void serdev_device_release(struct device *dev)
{
	struct serdev_device *serdev = to_serdev_device(dev);
	kfree(serdev);
}

static const struct device_type serdev_device_type = {
	.release	= serdev_device_release,
};

static void serdev_ctrl_release(struct device *dev)
{
	struct serdev_controller *ctrl = to_serdev_controller(dev);
	ida_simple_remove(&ctrl_ida, ctrl->nr);
	kfree(ctrl);
}

static const struct device_type serdev_ctrl_type = {
	.release	= serdev_ctrl_release,
};

static int serdev_device_match(struct device *dev, struct device_driver *drv)
{
	/* TODO: platform matching */
	if (acpi_driver_match_device(dev, drv))
		return 1;

	return of_driver_match_device(dev, drv);
}

static int serdev_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	int rc;

	/* TODO: platform modalias */
	rc = acpi_device_uevent_modalias(dev, env);
	if (rc != -ENODEV)
		return rc;

	return of_device_uevent_modalias(dev, env);
}

/**
 * serdev_device_add() - add a device previously constructed via serdev_device_alloc()
 * @serdev:	serdev_device to be added
 */
int serdev_device_add(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;
	struct device *parent = serdev->dev.parent;
	int err;

	dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);

	/* Only a single slave device is currently supported. */
	if (ctrl->serdev) {
		dev_err(&serdev->dev, "controller busy\n");
		return -EBUSY;
	}
	ctrl->serdev = serdev;

	err = device_add(&serdev->dev);
	if (err < 0) {
		dev_err(&serdev->dev, "Can't add %s, status %d\n",
			dev_name(&serdev->dev), err);
		goto err_clear_serdev;
	}

	dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));

	return 0;

err_clear_serdev:
	ctrl->serdev = NULL;
	return err;
}
EXPORT_SYMBOL_GPL(serdev_device_add);

/**
 * serdev_device_remove(): remove an serdev device
 * @serdev:	serdev_device to be removed
 */
void serdev_device_remove(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	device_unregister(&serdev->dev);
	ctrl->serdev = NULL;
}
EXPORT_SYMBOL_GPL(serdev_device_remove);

int serdev_device_open(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->open)
		return -EINVAL;

	return ctrl->ops->open(ctrl);
}
EXPORT_SYMBOL_GPL(serdev_device_open);

void serdev_device_close(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->close)
		return;

	ctrl->ops->close(ctrl);
}
EXPORT_SYMBOL_GPL(serdev_device_close);

void serdev_device_write_wakeup(struct serdev_device *serdev)
{
	complete(&serdev->write_comp);
}
EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);

int serdev_device_write_buf(struct serdev_device *serdev,
			    const unsigned char *buf, size_t count)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->write_buf)
		return -EINVAL;

	return ctrl->ops->write_buf(ctrl, buf, count);
}
EXPORT_SYMBOL_GPL(serdev_device_write_buf);

int serdev_device_write(struct serdev_device *serdev,
			const unsigned char *buf, size_t count,
			unsigned long timeout)
{
	struct serdev_controller *ctrl = serdev->ctrl;
	int ret;

	if (!ctrl || !ctrl->ops->write_buf ||
	    (timeout && !serdev->ops->write_wakeup))
		return -EINVAL;

	mutex_lock(&serdev->write_lock);
	do {
		reinit_completion(&serdev->write_comp);

		ret = ctrl->ops->write_buf(ctrl, buf, count);
		if (ret < 0)
			break;

		buf += ret;
		count -= ret;

	} while (count &&
		 (timeout = wait_for_completion_timeout(&serdev->write_comp,
							timeout)));
	mutex_unlock(&serdev->write_lock);
	return ret < 0 ? ret : (count ? -ETIMEDOUT : 0);
}
EXPORT_SYMBOL_GPL(serdev_device_write);

void serdev_device_write_flush(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->write_flush)
		return;

	ctrl->ops->write_flush(ctrl);
}
EXPORT_SYMBOL_GPL(serdev_device_write_flush);

int serdev_device_write_room(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->write_room)
		return 0;

	return serdev->ctrl->ops->write_room(ctrl);
}
EXPORT_SYMBOL_GPL(serdev_device_write_room);

unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->set_baudrate)
		return 0;

	return ctrl->ops->set_baudrate(ctrl, speed);

}
EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);

void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->set_flow_control)
		return;

	ctrl->ops->set_flow_control(ctrl, enable);
}
EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);

void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->wait_until_sent)
		return;

	ctrl->ops->wait_until_sent(ctrl, timeout);
}
EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);

int serdev_device_get_tiocm(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->get_tiocm)
		return -ENOTSUPP;

	return ctrl->ops->get_tiocm(ctrl);
}
EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);

int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->set_tiocm)
		return -ENOTSUPP;

	return ctrl->ops->set_tiocm(ctrl, set, clear);
}
EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);

static int serdev_drv_probe(struct device *dev)
{
	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);

	return sdrv->probe(to_serdev_device(dev));
}

static int serdev_drv_remove(struct device *dev)
{
	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);

	sdrv->remove(to_serdev_device(dev));
	return 0;
}

static ssize_t modalias_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	int len;

	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
	if (len != -ENODEV)
		return len;

	return of_device_modalias(dev, buf, PAGE_SIZE);
}
DEVICE_ATTR_RO(modalias);

static struct attribute *serdev_device_attrs[] = {
	&dev_attr_modalias.attr,
	NULL,
};
ATTRIBUTE_GROUPS(serdev_device);

static struct bus_type serdev_bus_type = {
	.name		= "serial",
	.match		= serdev_device_match,
	.probe		= serdev_drv_probe,
	.remove		= serdev_drv_remove,
	.uevent		= serdev_uevent,
	.dev_groups	= serdev_device_groups,
};

/**
 * serdev_controller_alloc() - Allocate a new serdev device
 * @ctrl:	associated controller
 *
 * Caller is responsible for either calling serdev_device_add() to add the
 * newly allocated controller, or calling serdev_device_put() to discard it.
 */
struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl)
{
	struct serdev_device *serdev;

	serdev = kzalloc(sizeof(*serdev), GFP_KERNEL);
	if (!serdev)
		return NULL;

	serdev->ctrl = ctrl;
	device_initialize(&serdev->dev);
	serdev->dev.parent = &ctrl->dev;
	serdev->dev.bus = &serdev_bus_type;
	serdev->dev.type = &serdev_device_type;
	init_completion(&serdev->write_comp);
	mutex_init(&serdev->write_lock);
	return serdev;
}
EXPORT_SYMBOL_GPL(serdev_device_alloc);

/**
 * serdev_controller_alloc() - Allocate a new serdev controller
 * @parent:	parent device
 * @size:	size of private data
 *
 * Caller is responsible for either calling serdev_controller_add() to add the
 * newly allocated controller, or calling serdev_controller_put() to discard it.
 * The allocated private data region may be accessed via
 * serdev_controller_get_drvdata()
 */
struct serdev_controller *serdev_controller_alloc(struct device *parent,
					      size_t size)
{
	struct serdev_controller *ctrl;
	int id;

	if (WARN_ON(!parent))
		return NULL;

	ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
	if (!ctrl)
		return NULL;

	id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
	if (id < 0) {
		dev_err(parent,
			"unable to allocate serdev controller identifier.\n");
		goto err_free;
	}

	ctrl->nr = id;

	device_initialize(&ctrl->dev);
	ctrl->dev.type = &serdev_ctrl_type;
	ctrl->dev.bus = &serdev_bus_type;
	ctrl->dev.parent = parent;
	ctrl->dev.of_node = parent->of_node;
	serdev_controller_set_drvdata(ctrl, &ctrl[1]);

	dev_set_name(&ctrl->dev, "serial%d", id);

	dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
	return ctrl;

err_free:
	kfree(ctrl);

	return NULL;
}
EXPORT_SYMBOL_GPL(serdev_controller_alloc);

static int of_serdev_register_devices(struct serdev_controller *ctrl)
{
	struct device_node *node;
	struct serdev_device *serdev = NULL;
	int err;
	bool found = false;

	for_each_available_child_of_node(ctrl->dev.of_node, node) {
		if (!of_get_property(node, "compatible", NULL))
			continue;

		dev_dbg(&ctrl->dev, "adding child %pOF\n", node);

		serdev = serdev_device_alloc(ctrl);
		if (!serdev)
			continue;

		serdev->dev.of_node = node;

		err = serdev_device_add(serdev);
		if (err) {
			dev_err(&serdev->dev,
				"failure adding device. status %d\n", err);
			serdev_device_put(serdev);
		} else
			found = true;
	}
	if (!found)
		return -ENODEV;

	return 0;
}

#ifdef CONFIG_ACPI
static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
					    struct acpi_device *adev)
{
	struct serdev_device *serdev = NULL;
	int err;

	if (acpi_bus_get_status(adev) || !adev->status.present ||
	    acpi_device_enumerated(adev))
		return AE_OK;

	serdev = serdev_device_alloc(ctrl);
	if (!serdev) {
		dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
			dev_name(&adev->dev));
		return AE_NO_MEMORY;
	}

	ACPI_COMPANION_SET(&serdev->dev, adev);
	acpi_device_set_enumerated(adev);

	err = serdev_device_add(serdev);
	if (err) {
		dev_err(&serdev->dev,
			"failure adding ACPI serdev device. status %d\n", err);
		serdev_device_put(serdev);
	}

	return AE_OK;
}

static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
				       void *data, void **return_value)
{
	struct serdev_controller *ctrl = data;
	struct acpi_device *adev;

	if (acpi_bus_get_device(handle, &adev))
		return AE_OK;

	return acpi_serdev_register_device(ctrl, adev);
}

static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
{
	acpi_status status;
	acpi_handle handle;

	handle = ACPI_HANDLE(ctrl->dev.parent);
	if (!handle)
		return -ENODEV;

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
				     acpi_serdev_add_device, NULL, ctrl, NULL);
	if (ACPI_FAILURE(status))
		dev_dbg(&ctrl->dev, "failed to enumerate serdev slaves\n");

	if (!ctrl->serdev)
		return -ENODEV;

	return 0;
}
#else
static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
{
	return -ENODEV;
}
#endif /* CONFIG_ACPI */

/**
 * serdev_controller_add() - Add an serdev controller
 * @ctrl:	controller to be registered.
 *
 * Register a controller previously allocated via serdev_controller_alloc() with
 * the serdev core.
 */
int serdev_controller_add(struct serdev_controller *ctrl)
{
	int ret_of, ret_acpi, ret;

	/* Can't register until after driver model init */
	if (WARN_ON(!is_registered))
		return -EAGAIN;

	ret = device_add(&ctrl->dev);
	if (ret)
		return ret;

	ret_of = of_serdev_register_devices(ctrl);
	ret_acpi = acpi_serdev_register_devices(ctrl);
	if (ret_of && ret_acpi) {
		dev_dbg(&ctrl->dev, "no devices registered: of:%d acpi:%d\n",
			ret_of, ret_acpi);
		ret = -ENODEV;
		goto out_dev_del;
	}

	dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
		ctrl->nr, &ctrl->dev);
	return 0;

out_dev_del:
	device_del(&ctrl->dev);
	return ret;
};
EXPORT_SYMBOL_GPL(serdev_controller_add);

/* Remove a device associated with a controller */
static int serdev_remove_device(struct device *dev, void *data)
{
	struct serdev_device *serdev = to_serdev_device(dev);
	if (dev->type == &serdev_device_type)
		serdev_device_remove(serdev);
	return 0;
}

/**
 * serdev_controller_remove(): remove an serdev controller
 * @ctrl:	controller to remove
 *
 * Remove a serdev controller.  Caller is responsible for calling
 * serdev_controller_put() to discard the allocated controller.
 */
void serdev_controller_remove(struct serdev_controller *ctrl)
{
	int dummy;

	if (!ctrl)
		return;

	dummy = device_for_each_child(&ctrl->dev, NULL,
				      serdev_remove_device);
	device_del(&ctrl->dev);
}
EXPORT_SYMBOL_GPL(serdev_controller_remove);

/**
 * serdev_driver_register() - Register client driver with serdev core
 * @sdrv:	client driver to be associated with client-device.
 *
 * This API will register the client driver with the serdev framework.
 * It is typically called from the driver's module-init function.
 */
int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner)
{
	sdrv->driver.bus = &serdev_bus_type;
	sdrv->driver.owner = owner;

	/* force drivers to async probe so I/O is possible in probe */
        sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;

	return driver_register(&sdrv->driver);
}
EXPORT_SYMBOL_GPL(__serdev_device_driver_register);

static void __exit serdev_exit(void)
{
	bus_unregister(&serdev_bus_type);
}
module_exit(serdev_exit);

static int __init serdev_init(void)
{
	int ret;

	ret = bus_register(&serdev_bus_type);
	if (ret)
		return ret;

	is_registered = true;
	return 0;
}
/* Must be before serial drivers register */
postcore_initcall(serdev_init);

MODULE_AUTHOR("Rob Herring <robh@kernel.org>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Serial attached device bus");
Commit	Line	Data
e3b3d0f5	1	// SPDX-License-Identifier: GPL-2.0
cd6484e1 RH	2	/*
	3	* Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
	4	*
	5	* Based on drivers/spmi/spmi.c:
	6	* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
cd6484e1 RH	7	*/
cd6484e1 RH	8
53c76263	9	#include <linux/acpi.h>
cd6484e1 RH	10	#include <linux/errno.h>
	11	#include <linux/idr.h>
	12	#include <linux/kernel.h>
	13	#include <linux/module.h>
	14	#include <linux/of.h>
	15	#include <linux/of_device.h>
	16	#include <linux/serdev.h>
	17	#include <linux/slab.h>
	18
	19	static bool is_registered;
	20	static DEFINE_IDA(ctrl_ida);
	21
	22	static void serdev_device_release(struct device *dev)
	23	{
	24	struct serdev_device *serdev = to_serdev_device(dev);
	25	kfree(serdev);
	26	}
	27
	28	static const struct device_type serdev_device_type = {
	29	.release = serdev_device_release,
	30	};
	31
	32	static void serdev_ctrl_release(struct device *dev)
	33	{
	34	struct serdev_controller *ctrl = to_serdev_controller(dev);
	35	ida_simple_remove(&ctrl_ida, ctrl->nr);
	36	kfree(ctrl);
	37	}
	38
	39	static const struct device_type serdev_ctrl_type = {
	40	.release = serdev_ctrl_release,
	41	};
	42
	43	static int serdev_device_match(struct device dev, struct device_driver drv)
	44	{
53c76263 FD	45	/* TODO: platform matching */
	46	if (acpi_driver_match_device(dev, drv))
	47	return 1;
	48
cd6484e1 RH	49	return of_driver_match_device(dev, drv);
	50	}
	51
	52	static int serdev_uevent(struct device dev, struct kobj_uevent_env env)
	53	{
53c76263 FD	54	int rc;
	55
	56	/* TODO: platform modalias */
	57	rc = acpi_device_uevent_modalias(dev, env);
	58	if (rc != -ENODEV)
	59	return rc;
	60
cd6484e1 RH	61	return of_device_uevent_modalias(dev, env);
	62	}
	63
	64	/**
	65	* serdev_device_add() - add a device previously constructed via serdev_device_alloc()
	66	* @serdev: serdev_device to be added
	67	*/
	68	int serdev_device_add(struct serdev_device *serdev)
	69	{
08fcee28	70	struct serdev_controller *ctrl = serdev->ctrl;
cd6484e1 RH	71	struct device *parent = serdev->dev.parent;
	72	int err;
	73
	74	dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);
	75
08fcee28 JH	76	/* Only a single slave device is currently supported. */
	77	if (ctrl->serdev) {
	78	dev_err(&serdev->dev, "controller busy\n");
	79	return -EBUSY;
	80	}
	81	ctrl->serdev = serdev;
	82
cd6484e1 RH	83	err = device_add(&serdev->dev);
	84	if (err < 0) {
	85	dev_err(&serdev->dev, "Can't add %s, status %d\n",
	86	dev_name(&serdev->dev), err);
08fcee28	87	goto err_clear_serdev;
cd6484e1 RH	88	}
	89
	90	dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
	91
08fcee28 JH	92	return 0;
	93
	94	err_clear_serdev:
	95	ctrl->serdev = NULL;
cd6484e1 RH	96	return err;
	97	}
	98	EXPORT_SYMBOL_GPL(serdev_device_add);
	99
	100	/**
	101	* serdev_device_remove(): remove an serdev device
	102	* @serdev: serdev_device to be removed
	103	*/
	104	void serdev_device_remove(struct serdev_device *serdev)
	105	{
08fcee28 JH	106	struct serdev_controller *ctrl = serdev->ctrl;
08fcee28 JH	107
cd6484e1	108	device_unregister(&serdev->dev);
08fcee28	109	ctrl->serdev = NULL;
cd6484e1 RH	110	}
	111	EXPORT_SYMBOL_GPL(serdev_device_remove);
	112
	113	int serdev_device_open(struct serdev_device *serdev)
	114	{
	115	struct serdev_controller *ctrl = serdev->ctrl;
	116
	117	if (!ctrl \|\| !ctrl->ops->open)
	118	return -EINVAL;
	119
	120	return ctrl->ops->open(ctrl);
	121	}
	122	EXPORT_SYMBOL_GPL(serdev_device_open);
	123
	124	void serdev_device_close(struct serdev_device *serdev)
	125	{
	126	struct serdev_controller *ctrl = serdev->ctrl;
	127
	128	if (!ctrl \|\| !ctrl->ops->close)
	129	return;
	130
	131	ctrl->ops->close(ctrl);
	132	}
	133	EXPORT_SYMBOL_GPL(serdev_device_close);
	134
6fe729c4 AS	135	void serdev_device_write_wakeup(struct serdev_device *serdev)
	136	{
	137	complete(&serdev->write_comp);
	138	}
	139	EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
	140
6bdc00d0 SW	141	int serdev_device_write_buf(struct serdev_device *serdev,
	142	const unsigned char *buf, size_t count)
	143	{
	144	struct serdev_controller *ctrl = serdev->ctrl;
	145
	146	if (!ctrl \|\| !ctrl->ops->write_buf)
	147	return -EINVAL;
	148
	149	return ctrl->ops->write_buf(ctrl, buf, count);
	150	}
	151	EXPORT_SYMBOL_GPL(serdev_device_write_buf);
	152
6fe729c4 AS	153	int serdev_device_write(struct serdev_device *serdev,
	154	const unsigned char *buf, size_t count,
	155	unsigned long timeout)
cd6484e1 RH	156	{
cd6484e1 RH	157	struct serdev_controller *ctrl = serdev->ctrl;
6fe729c4	158	int ret;
cd6484e1	159
6fe729c4 AS	160	if (!ctrl \|\| !ctrl->ops->write_buf \|\|
6fe729c4 AS	161	(timeout && !serdev->ops->write_wakeup))
cd6484e1 RH	162	return -EINVAL;
cd6484e1 RH	163
6fe729c4 AS	164	mutex_lock(&serdev->write_lock);
	165	do {
	166	reinit_completion(&serdev->write_comp);
	167
	168	ret = ctrl->ops->write_buf(ctrl, buf, count);
	169	if (ret < 0)
	170	break;
	171
	172	buf += ret;
	173	count -= ret;
	174
	175	} while (count &&
	176	(timeout = wait_for_completion_timeout(&serdev->write_comp,
	177	timeout)));
	178	mutex_unlock(&serdev->write_lock);
	179	return ret < 0 ? ret : (count ? -ETIMEDOUT : 0);
cd6484e1	180	}
6fe729c4	181	EXPORT_SYMBOL_GPL(serdev_device_write);
cd6484e1 RH	182
	183	void serdev_device_write_flush(struct serdev_device *serdev)
	184	{
	185	struct serdev_controller *ctrl = serdev->ctrl;
	186
	187	if (!ctrl \|\| !ctrl->ops->write_flush)
	188	return;
	189
	190	ctrl->ops->write_flush(ctrl);
	191	}
	192	EXPORT_SYMBOL_GPL(serdev_device_write_flush);
	193
	194	int serdev_device_write_room(struct serdev_device *serdev)
	195	{
	196	struct serdev_controller *ctrl = serdev->ctrl;
	197
	198	if (!ctrl \|\| !ctrl->ops->write_room)
	199	return 0;
	200
	201	return serdev->ctrl->ops->write_room(ctrl);
	202	}
	203	EXPORT_SYMBOL_GPL(serdev_device_write_room);
	204
	205	unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
	206	{
	207	struct serdev_controller *ctrl = serdev->ctrl;
	208
	209	if (!ctrl \|\| !ctrl->ops->set_baudrate)
	210	return 0;
	211
	212	return ctrl->ops->set_baudrate(ctrl, speed);
	213
	214	}
	215	EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);
	216
	217	void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
	218	{
	219	struct serdev_controller *ctrl = serdev->ctrl;
	220
	221	if (!ctrl \|\| !ctrl->ops->set_flow_control)
	222	return;
	223
	224	ctrl->ops->set_flow_control(ctrl, enable);
	225	}
	226	EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);
	227
b3f80c8f SR	228	void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
	229	{
	230	struct serdev_controller *ctrl = serdev->ctrl;
	231
	232	if (!ctrl \|\| !ctrl->ops->wait_until_sent)
	233	return;
	234
	235	ctrl->ops->wait_until_sent(ctrl, timeout);
	236	}
	237	EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);
	238
5659dab2 SR	239	int serdev_device_get_tiocm(struct serdev_device *serdev)
	240	{
	241	struct serdev_controller *ctrl = serdev->ctrl;
	242
	243	if (!ctrl \|\| !ctrl->ops->get_tiocm)
	244	return -ENOTSUPP;
	245
	246	return ctrl->ops->get_tiocm(ctrl);
	247	}
	248	EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);
	249
	250	int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
	251	{
	252	struct serdev_controller *ctrl = serdev->ctrl;
	253
	254	if (!ctrl \|\| !ctrl->ops->set_tiocm)
	255	return -ENOTSUPP;
	256
	257	return ctrl->ops->set_tiocm(ctrl, set, clear);
	258	}
	259	EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);
	260
cd6484e1 RH	261	static int serdev_drv_probe(struct device *dev)
	262	{
	263	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
	264
	265	return sdrv->probe(to_serdev_device(dev));
	266	}
	267
	268	static int serdev_drv_remove(struct device *dev)
	269	{
	270	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
	271
	272	sdrv->remove(to_serdev_device(dev));
	273	return 0;
	274	}
	275
	276	static ssize_t modalias_show(struct device *dev,
	277	struct device_attribute attr, char buf)
	278	{
53c76263 FD	279	int len;
	280
	281	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
	282	if (len != -ENODEV)
	283	return len;
	284
0634c295	285	return of_device_modalias(dev, buf, PAGE_SIZE);
cd6484e1	286	}
4fe99816	287	DEVICE_ATTR_RO(modalias);
cd6484e1	288
4fe99816 GKH	289	static struct attribute *serdev_device_attrs[] = {
	290	&dev_attr_modalias.attr,
	291	NULL,
cd6484e1	292	};
4fe99816	293	ATTRIBUTE_GROUPS(serdev_device);
cd6484e1 RH	294
	295	static struct bus_type serdev_bus_type = {
	296	.name = "serial",
	297	.match = serdev_device_match,
	298	.probe = serdev_drv_probe,
	299	.remove = serdev_drv_remove,
	300	.uevent = serdev_uevent,
4fe99816	301	.dev_groups = serdev_device_groups,
cd6484e1 RH	302	};
	303
	304	/**
	305	* serdev_controller_alloc() - Allocate a new serdev device
	306	* @ctrl: associated controller
	307	*
	308	* Caller is responsible for either calling serdev_device_add() to add the
	309	* newly allocated controller, or calling serdev_device_put() to discard it.
	310	*/
	311	struct serdev_device serdev_device_alloc(struct serdev_controller ctrl)
	312	{
	313	struct serdev_device *serdev;
	314
	315	serdev = kzalloc(sizeof(*serdev), GFP_KERNEL);
	316	if (!serdev)
	317	return NULL;
	318
	319	serdev->ctrl = ctrl;
cd6484e1 RH	320	device_initialize(&serdev->dev);
	321	serdev->dev.parent = &ctrl->dev;
	322	serdev->dev.bus = &serdev_bus_type;
	323	serdev->dev.type = &serdev_device_type;
6fe729c4 AS	324	init_completion(&serdev->write_comp);
6fe729c4 AS	325	mutex_init(&serdev->write_lock);
cd6484e1 RH	326	return serdev;
	327	}
	328	EXPORT_SYMBOL_GPL(serdev_device_alloc);
	329
	330	/**
	331	* serdev_controller_alloc() - Allocate a new serdev controller
	332	* @parent: parent device
	333	* @size: size of private data
	334	*
	335	* Caller is responsible for either calling serdev_controller_add() to add the
	336	* newly allocated controller, or calling serdev_controller_put() to discard it.
	337	* The allocated private data region may be accessed via
	338	* serdev_controller_get_drvdata()
	339	*/
	340	struct serdev_controller serdev_controller_alloc(struct device parent,
	341	size_t size)
	342	{
	343	struct serdev_controller *ctrl;
	344	int id;
	345
	346	if (WARN_ON(!parent))
	347	return NULL;
	348
	349	ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
	350	if (!ctrl)
	351	return NULL;
	352
cd6484e1 RH	353	id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
	354	if (id < 0) {
	355	dev_err(parent,
	356	"unable to allocate serdev controller identifier.\n");
978d6fac	357	goto err_free;
cd6484e1 RH	358	}
	359
	360	ctrl->nr = id;
978d6fac JH	361
	362	device_initialize(&ctrl->dev);
	363	ctrl->dev.type = &serdev_ctrl_type;
	364	ctrl->dev.bus = &serdev_bus_type;
	365	ctrl->dev.parent = parent;
	366	ctrl->dev.of_node = parent->of_node;
	367	serdev_controller_set_drvdata(ctrl, &ctrl[1]);
	368
cd6484e1 RH	369	dev_set_name(&ctrl->dev, "serial%d", id);
	370
	371	dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
	372	return ctrl;
978d6fac JH	373
	374	err_free:
	375	kfree(ctrl);
	376
	377	return NULL;
cd6484e1 RH	378	}
	379	EXPORT_SYMBOL_GPL(serdev_controller_alloc);
	380
	381	static int of_serdev_register_devices(struct serdev_controller *ctrl)
	382	{
	383	struct device_node *node;
	384	struct serdev_device *serdev = NULL;
	385	int err;
	386	bool found = false;
	387
	388	for_each_available_child_of_node(ctrl->dev.of_node, node) {
	389	if (!of_get_property(node, "compatible", NULL))
	390	continue;
	391
a73ee843	392	dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
cd6484e1 RH	393
	394	serdev = serdev_device_alloc(ctrl);
	395	if (!serdev)
	396	continue;
	397
	398	serdev->dev.of_node = node;
	399
	400	err = serdev_device_add(serdev);
	401	if (err) {
	402	dev_err(&serdev->dev,
	403	"failure adding device. status %d\n", err);
	404	serdev_device_put(serdev);
	405	} else
	406	found = true;
	407	}
	408	if (!found)
	409	return -ENODEV;
	410
	411	return 0;
	412	}
	413
53c76263 FD	414	#ifdef CONFIG_ACPI
	415	static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
	416	struct acpi_device *adev)
	417	{
	418	struct serdev_device *serdev = NULL;
	419	int err;
	420
	421	if (acpi_bus_get_status(adev) \|\| !adev->status.present \|\|
	422	acpi_device_enumerated(adev))
	423	return AE_OK;
	424
	425	serdev = serdev_device_alloc(ctrl);
	426	if (!serdev) {
	427	dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
	428	dev_name(&adev->dev));
	429	return AE_NO_MEMORY;
	430	}
	431
	432	ACPI_COMPANION_SET(&serdev->dev, adev);
	433	acpi_device_set_enumerated(adev);
	434
	435	err = serdev_device_add(serdev);
	436	if (err) {
	437	dev_err(&serdev->dev,
	438	"failure adding ACPI serdev device. status %d\n", err);
	439	serdev_device_put(serdev);
	440	}
	441
	442	return AE_OK;
	443	}
	444
	445	static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
	446	void data, void *return_value)
	447	{
	448	struct serdev_controller *ctrl = data;
	449	struct acpi_device *adev;
	450
	451	if (acpi_bus_get_device(handle, &adev))
	452	return AE_OK;
	453
	454	return acpi_serdev_register_device(ctrl, adev);
	455	}
	456
	457	static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
	458	{
	459	acpi_status status;
	460	acpi_handle handle;
	461
	462	handle = ACPI_HANDLE(ctrl->dev.parent);
	463	if (!handle)
	464	return -ENODEV;
	465
	466	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
	467	acpi_serdev_add_device, NULL, ctrl, NULL);
	468	if (ACPI_FAILURE(status))
	469	dev_dbg(&ctrl->dev, "failed to enumerate serdev slaves\n");
	470
	471	if (!ctrl->serdev)
	472	return -ENODEV;
	473
	474	return 0;
	475	}
	476	#else
	477	static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
478	{
479	return -ENODEV;
480	}
481	#endif /* CONFIG_ACPI */
482
cd6484e1 RH	483	/**
	484	* serdev_controller_add() - Add an serdev controller
	485	* @ctrl: controller to be registered.
	486	*
	487	* Register a controller previously allocated via serdev_controller_alloc() with
	488	* the serdev core.
	489	*/
	490	int serdev_controller_add(struct serdev_controller *ctrl)
	491	{
53c76263	492	int ret_of, ret_acpi, ret;
cd6484e1 RH	493
	494	/* Can't register until after driver model init */
	495	if (WARN_ON(!is_registered))
	496	return -EAGAIN;
	497
	498	ret = device_add(&ctrl->dev);
	499	if (ret)
	500	return ret;
	501
53c76263 FD	502	ret_of = of_serdev_register_devices(ctrl);
	503	ret_acpi = acpi_serdev_register_devices(ctrl);
	504	if (ret_of && ret_acpi) {
	505	dev_dbg(&ctrl->dev, "no devices registered: of:%d acpi:%d\n",
	506	ret_of, ret_acpi);
	507	ret = -ENODEV;
cd6484e1	508	goto out_dev_del;
53c76263	509	}
cd6484e1 RH	510
	511	dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
	512	ctrl->nr, &ctrl->dev);
	513	return 0;
	514
	515	out_dev_del:
	516	device_del(&ctrl->dev);
	517	return ret;
	518	};
	519	EXPORT_SYMBOL_GPL(serdev_controller_add);
	520
	521	/* Remove a device associated with a controller */
	522	static int serdev_remove_device(struct device dev, void data)
	523	{
	524	struct serdev_device *serdev = to_serdev_device(dev);
	525	if (dev->type == &serdev_device_type)
	526	serdev_device_remove(serdev);
	527	return 0;
	528	}
	529
	530	/**
	531	* serdev_controller_remove(): remove an serdev controller
	532	* @ctrl: controller to remove
	533	*
	534	* Remove a serdev controller. Caller is responsible for calling
	535	* serdev_controller_put() to discard the allocated controller.
	536	*/
	537	void serdev_controller_remove(struct serdev_controller *ctrl)
	538	{
	539	int dummy;
	540
	541	if (!ctrl)
	542	return;
	543
	544	dummy = device_for_each_child(&ctrl->dev, NULL,
	545	serdev_remove_device);
	546	device_del(&ctrl->dev);
	547	}
	548	EXPORT_SYMBOL_GPL(serdev_controller_remove);
	549
	550	/**
	551	* serdev_driver_register() - Register client driver with serdev core
	552	* @sdrv: client driver to be associated with client-device.
	553	*
	554	* This API will register the client driver with the serdev framework.
	555	* It is typically called from the driver's module-init function.
	556	*/
	557	int __serdev_device_driver_register(struct serdev_device_driver sdrv, struct module owner)
	558	{
	559	sdrv->driver.bus = &serdev_bus_type;
	560	sdrv->driver.owner = owner;
	561
	562	/* force drivers to async probe so I/O is possible in probe */
	563	sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;
	564
	565	return driver_register(&sdrv->driver);
	566	}
	567	EXPORT_SYMBOL_GPL(__serdev_device_driver_register);
	568
	569	static void __exit serdev_exit(void)
	570	{
	571	bus_unregister(&serdev_bus_type);
	572	}
	573	module_exit(serdev_exit);
574
575	static int __init serdev_init(void)
576	{
577	int ret;
578
579	ret = bus_register(&serdev_bus_type);
580	if (ret)
581	return ret;
582
583	is_registered = true;
584	return 0;
585	}
586	/* Must be before serial drivers register */
587	postcore_initcall(serdev_init);
588
589	MODULE_AUTHOR("Rob Herring <robh@kernel.org>");
590	MODULE_LICENSE("GPL v2");
591	MODULE_DESCRIPTION("Serial attached device bus");