linux/drivers/tty/serdev/core.c

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/*
* 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.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#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: ACPI and platform matching */
return of_driver_match_device(dev, drv);
}
static int serdev_uevent(struct device *dev, struct kobj_uevent_env *env)
{
/* TODO: ACPI and platform modalias */
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 device *parent = serdev->dev.parent;
int err;
dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);
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_device_add;
}
dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
err_device_add:
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)
{
device_unregister(&serdev->dev);
}
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(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)
{
return of_device_modalias(dev, buf, PAGE_SIZE);
}
static struct device_attribute serdev_device_attrs[] = {
__ATTR_RO(modalias),
__ATTR_NULL
};
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_attrs = serdev_device_attrs,
};
/**
* 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;
ctrl->serdev = serdev;
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;
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]);
id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
if (id < 0) {
dev_err(parent,
"unable to allocate serdev controller identifier.\n");
serdev_controller_put(ctrl);
return NULL;
}
ctrl->nr = id;
dev_set_name(&ctrl->dev, "serial%d", id);
dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
return ctrl;
}
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 %s\n", node->full_name);
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;
}
/**
* 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;
/* 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_serdev_register_devices(ctrl);
if (ret)
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");