linuxdebug/drivers/char/ipmi/kcs_bmc_serio.c

160 lines
3.7 KiB
C

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