// SPDX-License-Identifier: GPL-2.0/* * Microchip PolarFire SoC (MPFS) system controller driver * * Copyright (c) 2020-2021 Microchip Corporation. All rights reserved. * * Author: Conor Dooley <conor.dooley@microchip.com> * */ #include <linux/slab.h>#include <linux/kref.h>#include <linux/module.h>#include <linux/interrupt.h>#include <linux/of_platform.h>#include <linux/mailbox_client.h>#include <linux/platform_device.h>#include <soc/microchip/mpfs.h> static DEFINE_MUTEX(transaction_lock); struct mpfs_sys_controller {	struct mbox_client client;	struct mbox_chan *chan;	struct completion c;	struct kref consumers;}; int mpfs_blocking_transaction(struct mpfs_sys_controller *sys_controller, struct mpfs_mss_msg *msg){	int ret, err; 	err = mutex_lock_interruptible(&transaction_lock);	if (err)		return err; 	reinit_completion(&sys_controller->c); 	ret = mbox_send_message(sys_controller->chan, msg);	if (ret >= 0) {		if (wait_for_completion_timeout(&sys_controller->c, HZ)) {			ret = 0;		} else {			ret = -ETIMEDOUT;			dev_warn(sys_controller->client.dev,				 "MPFS sys controller transaction timeout\n");		}	} else {		dev_err(sys_controller->client.dev,			"mpfs sys controller transaction returned %d\n", ret);	} 	mutex_unlock(&transaction_lock); 	return ret;}EXPORT_SYMBOL(mpfs_blocking_transaction); static void rx_callback(struct mbox_client *client, void *msg){	struct mpfs_sys_controller *sys_controller =		container_of(client, struct mpfs_sys_controller, client); 	complete(&sys_controller->c);} static void mpfs_sys_controller_delete(struct kref *kref){	struct mpfs_sys_controller *sys_controller = container_of(kref, struct mpfs_sys_controller,					       consumers); 	mbox_free_channel(sys_controller->chan);	kfree(sys_controller);} static void mpfs_sys_controller_put(void *data){	struct mpfs_sys_controller *sys_controller = data; 	kref_put(&sys_controller->consumers, mpfs_sys_controller_delete);} static struct platform_device subdevs[] = {	{		.name		= "mpfs-rng",		.id		= -1,	},	{		.name		= "mpfs-generic-service",		.id		= -1,	}}; static int mpfs_sys_controller_probe(struct platform_device *pdev){	struct device *dev = &pdev->dev;	struct mpfs_sys_controller *sys_controller;	int i, ret; 	sys_controller = kzalloc(sizeof(*sys_controller), GFP_KERNEL);	if (!sys_controller)		return -ENOMEM; 	sys_controller->client.dev = dev;	sys_controller->client.rx_callback = rx_callback;	sys_controller->client.tx_block = 1U; 	sys_controller->chan = mbox_request_channel(&sys_controller->client, 0);	if (IS_ERR(sys_controller->chan)) {		ret = dev_err_probe(dev, PTR_ERR(sys_controller->chan),				    "Failed to get mbox channel\n");		kfree(sys_controller);		return ret;	} 	init_completion(&sys_controller->c);	kref_init(&sys_controller->consumers); 	platform_set_drvdata(pdev, sys_controller); 	dev_info(&pdev->dev, "Registered MPFS system controller\n"); 	for (i = 0; i < ARRAY_SIZE(subdevs); i++) {		subdevs[i].dev.parent = dev;		if (platform_device_register(&subdevs[i]))			dev_warn(dev, "Error registering sub device %s\n", subdevs[i].name);	} 	return 0;} static int mpfs_sys_controller_remove(struct platform_device *pdev){	struct mpfs_sys_controller *sys_controller = platform_get_drvdata(pdev); 	mpfs_sys_controller_put(sys_controller); 	return 0;} static const struct of_device_id mpfs_sys_controller_of_match[] = {	{.compatible = "microchip,mpfs-sys-controller", },	{},};MODULE_DEVICE_TABLE(of, mpfs_sys_controller_of_match); struct mpfs_sys_controller *mpfs_sys_controller_get(struct device *dev){	const struct of_device_id *match;	struct mpfs_sys_controller *sys_controller;	int ret; 	if (!dev->parent)		goto err_no_device; 	match = of_match_node(mpfs_sys_controller_of_match,  dev->parent->of_node);	of_node_put(dev->parent->of_node);	if (!match)		goto err_no_device; 	sys_controller = dev_get_drvdata(dev->parent);	if (!sys_controller)		goto err_bad_device; 	if (!kref_get_unless_zero(&sys_controller->consumers))		goto err_bad_device; 	ret = devm_add_action_or_reset(dev, mpfs_sys_controller_put, sys_controller);	if (ret)		return ERR_PTR(ret); 	return sys_controller; err_no_device:	dev_dbg(dev, "Parent device was not an MPFS system controller\n");	return ERR_PTR(-ENODEV); err_bad_device:	dev_dbg(dev, "MPFS system controller found but could not register as a sub device\n");	return ERR_PTR(-EPROBE_DEFER);}EXPORT_SYMBOL(mpfs_sys_controller_get); static struct platform_driver mpfs_sys_controller_driver = {	.driver = {		.name = "mpfs-sys-controller",		.of_match_table = mpfs_sys_controller_of_match,	},	.probe = mpfs_sys_controller_probe,	.remove = mpfs_sys_controller_remove,};module_platform_driver(mpfs_sys_controller_driver); MODULE_LICENSE("GPL v2");MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");MODULE_DESCRIPTION("MPFS system controller driver");