// 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/jiffies.h>#include <linux/mtd/mtd.h>#include <linux/spi/spi.h>#include <linux/interrupt.h>#include <linux/of.h>#include <linux/mailbox_client.h>#include <linux/platform_device.h>#include <soc/microchip/mpfs.h> /* * This timeout must be long, as some services (example: image authentication) * take significant time to complete */#define MPFS_SYS_CTRL_TIMEOUT_MS 30000 static DEFINE_MUTEX(transaction_lock); struct mpfs_sys_controller {	struct mbox_client client;	struct mbox_chan *chan;	struct completion c;	struct mtd_info *flash;	struct kref consumers;}; int mpfs_blocking_transaction(struct mpfs_sys_controller *sys_controller, struct mpfs_mss_msg *msg){	unsigned long timeout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS);	int ret; 	ret = mutex_lock_interruptible(&transaction_lock);	if (ret)		return ret; 	reinit_completion(&sys_controller->c); 	ret = mbox_send_message(sys_controller->chan, msg);	if (ret < 0) {		dev_warn(sys_controller->client.dev, "MPFS sys controller service timeout\n");		goto out;	} 	/*	 * Unfortunately, the system controller will only deliver an interrupt	 * if a service succeeds. mbox_send_message() will block until the busy	 * flag is gone. If the busy flag is gone but no interrupt has arrived	 * to trigger the rx callback then the service can be deemed to have	 * failed.	 * The caller can then interrogate msg::response::resp_status to	 * determine the cause of the failure.	 * mbox_send_message() returns positive integers in the success path, so	 * ret needs to be cleared if we do get an interrupt.	 */	if (!wait_for_completion_timeout(&sys_controller->c, timeout)) {		ret = -EBADMSG;		dev_warn(sys_controller->client.dev,			 "MPFS sys controller service failed with status: %d\n",			 msg->response->resp_status);	} else {		ret = 0;	} out:	mutex_unlock(&transaction_lock); 	return ret;}EXPORT_SYMBOL(mpfs_blocking_transaction); static void mpfs_sys_controller_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);} struct mtd_info *mpfs_sys_controller_get_flash(struct mpfs_sys_controller *mpfs_client){	return mpfs_client->flash;}EXPORT_SYMBOL(mpfs_sys_controller_get_flash); static struct platform_device subdevs[] = {	{		.name		= "mpfs-rng",		.id		= -1,	},	{		.name		= "mpfs-generic-service",		.id		= -1,	},	{		.name		= "mpfs-auto-update",		.id		= -1,	},}; static int mpfs_sys_controller_probe(struct platform_device *pdev){	struct device *dev = &pdev->dev;	struct mpfs_sys_controller *sys_controller;	struct device_node *np;	int i, ret; 	sys_controller = kzalloc(sizeof(*sys_controller), GFP_KERNEL);	if (!sys_controller)		return -ENOMEM; 	np = of_parse_phandle(dev->of_node, "microchip,bitstream-flash", 0);	if (!np)		goto no_flash; 	sys_controller->flash = of_get_mtd_device_by_node(np);	of_node_put(np);	if (IS_ERR(sys_controller->flash))		return dev_err_probe(dev, PTR_ERR(sys_controller->flash), "Failed to get flash\n"); no_flash:	sys_controller->client.dev = dev;	sys_controller->client.rx_callback = mpfs_sys_controller_rx_callback;	sys_controller->client.tx_block = 1U;	sys_controller->client.tx_tout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS); 	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);  	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);	} 	dev_info(&pdev->dev, "Registered MPFS system controller\n"); 	return 0;} static void mpfs_sys_controller_remove(struct platform_device *pdev){	struct mpfs_sys_controller *sys_controller = platform_get_drvdata(pdev); 	mpfs_sys_controller_put(sys_controller);} 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");