160 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			160 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-or-later
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| /* Copyright (c) 2021 IBM Corp. */
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| 
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| #include <linux/delay.h>
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| #include <linux/device.h>
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| #include <linux/errno.h>
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| #include <linux/list.h>
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| #include <linux/module.h>
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| #include <linux/sched/signal.h>
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| #include <linux/serio.h>
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| #include <linux/slab.h>
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| 
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| #include "kcs_bmc_client.h"
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| 
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| struct kcs_bmc_serio {
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| 	struct list_head entry;
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| 
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| 	struct kcs_bmc_client client;
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| 	struct serio *port;
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| 
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| 	spinlock_t lock;
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| };
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| 
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| static inline struct kcs_bmc_serio *client_to_kcs_bmc_serio(struct kcs_bmc_client *client)
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| {
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| 	return container_of(client, struct kcs_bmc_serio, client);
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| }
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| 
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| static irqreturn_t kcs_bmc_serio_event(struct kcs_bmc_client *client)
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| {
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| 	struct kcs_bmc_serio *priv;
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| 	u8 handled = IRQ_NONE;
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| 	u8 status;
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| 
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| 	priv = client_to_kcs_bmc_serio(client);
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| 
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| 	spin_lock(&priv->lock);
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| 
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| 	status = kcs_bmc_read_status(client->dev);
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| 
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| 	if (status & KCS_BMC_STR_IBF)
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| 		handled = serio_interrupt(priv->port, kcs_bmc_read_data(client->dev), 0);
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| 
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| 	spin_unlock(&priv->lock);
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| 
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| 	return handled;
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| }
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| 
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| static const struct kcs_bmc_client_ops kcs_bmc_serio_client_ops = {
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| 	.event = kcs_bmc_serio_event,
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| };
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| 
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| static int kcs_bmc_serio_open(struct serio *port)
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| {
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| 	struct kcs_bmc_serio *priv = port->port_data;
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| 
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| 	return kcs_bmc_enable_device(priv->client.dev, &priv->client);
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| }
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| 
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| static void kcs_bmc_serio_close(struct serio *port)
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| {
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| 	struct kcs_bmc_serio *priv = port->port_data;
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| 
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| 	kcs_bmc_disable_device(priv->client.dev, &priv->client);
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| }
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| 
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| static DEFINE_SPINLOCK(kcs_bmc_serio_instances_lock);
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| static LIST_HEAD(kcs_bmc_serio_instances);
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| 
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| static int kcs_bmc_serio_add_device(struct kcs_bmc_device *kcs_bmc)
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| {
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| 	struct kcs_bmc_serio *priv;
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| 	struct serio *port;
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| 
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| 	priv = devm_kzalloc(kcs_bmc->dev, sizeof(*priv), GFP_KERNEL);
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| 	if (!priv)
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| 		return -ENOMEM;
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| 
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| 	/* Use kzalloc() as the allocation is cleaned up with kfree() via serio_unregister_port() */
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| 	port = kzalloc(sizeof(*port), GFP_KERNEL);
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| 	if (!port)
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| 		return -ENOMEM;
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| 
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| 	port->id.type = SERIO_8042;
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| 	port->open = kcs_bmc_serio_open;
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| 	port->close = kcs_bmc_serio_close;
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| 	port->port_data = priv;
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| 	port->dev.parent = kcs_bmc->dev;
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| 
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| 	spin_lock_init(&priv->lock);
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| 	priv->port = port;
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| 	priv->client.dev = kcs_bmc;
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| 	priv->client.ops = &kcs_bmc_serio_client_ops;
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| 
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| 	spin_lock_irq(&kcs_bmc_serio_instances_lock);
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| 	list_add(&priv->entry, &kcs_bmc_serio_instances);
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| 	spin_unlock_irq(&kcs_bmc_serio_instances_lock);
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| 
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| 	serio_register_port(port);
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| 
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| 	dev_info(kcs_bmc->dev, "Initialised serio client for channel %d", kcs_bmc->channel);
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| 
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| 	return 0;
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| }
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| 
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| static int kcs_bmc_serio_remove_device(struct kcs_bmc_device *kcs_bmc)
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| {
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| 	struct kcs_bmc_serio *priv = NULL, *pos;
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| 
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| 	spin_lock_irq(&kcs_bmc_serio_instances_lock);
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| 	list_for_each_entry(pos, &kcs_bmc_serio_instances, entry) {
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| 		if (pos->client.dev == kcs_bmc) {
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| 			priv = pos;
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| 			list_del(&pos->entry);
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| 			break;
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| 		}
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| 	}
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| 	spin_unlock_irq(&kcs_bmc_serio_instances_lock);
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| 
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| 	if (!priv)
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| 		return -ENODEV;
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| 
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| 	/* kfree()s priv->port via put_device() */
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| 	serio_unregister_port(priv->port);
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| 
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| 	/* Ensure the IBF IRQ is disabled if we were the active client */
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| 	kcs_bmc_disable_device(kcs_bmc, &priv->client);
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| 
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| 	devm_kfree(priv->client.dev->dev, priv);
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| 
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| 	return 0;
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| }
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| 
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| static const struct kcs_bmc_driver_ops kcs_bmc_serio_driver_ops = {
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| 	.add_device = kcs_bmc_serio_add_device,
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| 	.remove_device = kcs_bmc_serio_remove_device,
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| };
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| 
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| static struct kcs_bmc_driver kcs_bmc_serio_driver = {
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| 	.ops = &kcs_bmc_serio_driver_ops,
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| };
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| 
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| static int __init kcs_bmc_serio_init(void)
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| {
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| 	kcs_bmc_register_driver(&kcs_bmc_serio_driver);
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| 
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| 	return 0;
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| }
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| module_init(kcs_bmc_serio_init);
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| 
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| static void __exit kcs_bmc_serio_exit(void)
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| {
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| 	kcs_bmc_unregister_driver(&kcs_bmc_serio_driver);
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| }
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| module_exit(kcs_bmc_serio_exit);
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| 
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| MODULE_LICENSE("GPL v2");
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| MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
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| MODULE_DESCRIPTION("Adapter driver for serio access to BMC KCS devices");
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