/* * 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); 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); 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); 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){	ssize_t len = of_device_get_modalias(dev, buf, PAGE_SIZE - 2);	buf[len] = '\n';	buf[len+1] = 0;	return len+1;} 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;	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");