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1// SPDX-License-Identifier: GPL-2.0-or-later2/* Copyright (c) 2021 IBM Corp. */3 4#include <linux/delay.h>5#include <linux/device.h>6#include <linux/errno.h>7#include <linux/list.h>8#include <linux/module.h>9#include <linux/sched/signal.h>10#include <linux/serio.h>11#include <linux/slab.h>12 13#include "kcs_bmc_client.h"14 15struct kcs_bmc_serio {16 struct list_head entry;17 18 struct kcs_bmc_client client;19 struct serio *port;20 21 spinlock_t lock;22};23 24static inline struct kcs_bmc_serio *client_to_kcs_bmc_serio(struct kcs_bmc_client *client)25{26 return container_of(client, struct kcs_bmc_serio, client);27}28 29static irqreturn_t kcs_bmc_serio_event(struct kcs_bmc_client *client)30{31 struct kcs_bmc_serio *priv;32 u8 handled = IRQ_NONE;33 u8 status;34 35 priv = client_to_kcs_bmc_serio(client);36 37 spin_lock(&priv->lock);38 39 status = kcs_bmc_read_status(client->dev);40 41 if (status & KCS_BMC_STR_IBF)42 handled = serio_interrupt(priv->port, kcs_bmc_read_data(client->dev), 0);43 44 spin_unlock(&priv->lock);45 46 return handled;47}48 49static const struct kcs_bmc_client_ops kcs_bmc_serio_client_ops = {50 .event = kcs_bmc_serio_event,51};52 53static int kcs_bmc_serio_open(struct serio *port)54{55 struct kcs_bmc_serio *priv = port->port_data;56 57 return kcs_bmc_enable_device(priv->client.dev, &priv->client);58}59 60static void kcs_bmc_serio_close(struct serio *port)61{62 struct kcs_bmc_serio *priv = port->port_data;63 64 kcs_bmc_disable_device(priv->client.dev, &priv->client);65}66 67static DEFINE_SPINLOCK(kcs_bmc_serio_instances_lock);68static LIST_HEAD(kcs_bmc_serio_instances);69 70static int kcs_bmc_serio_add_device(struct kcs_bmc_device *kcs_bmc)71{72 struct kcs_bmc_serio *priv;73 struct serio *port;74 75 priv = devm_kzalloc(kcs_bmc->dev, sizeof(*priv), GFP_KERNEL);76 if (!priv)77 return -ENOMEM;78 79 /* Use kzalloc() as the allocation is cleaned up with kfree() via serio_unregister_port() */80 port = kzalloc(sizeof(*port), GFP_KERNEL);81 if (!port)82 return -ENOMEM;83 84 port->id.type = SERIO_8042;85 port->open = kcs_bmc_serio_open;86 port->close = kcs_bmc_serio_close;87 port->port_data = priv;88 port->dev.parent = kcs_bmc->dev;89 90 spin_lock_init(&priv->lock);91 priv->port = port;92 priv->client.dev = kcs_bmc;93 priv->client.ops = &kcs_bmc_serio_client_ops;94 95 spin_lock_irq(&kcs_bmc_serio_instances_lock);96 list_add(&priv->entry, &kcs_bmc_serio_instances);97 spin_unlock_irq(&kcs_bmc_serio_instances_lock);98 99 serio_register_port(port);100 101 dev_info(kcs_bmc->dev, "Initialised serio client for channel %d", kcs_bmc->channel);102 103 return 0;104}105 106static int kcs_bmc_serio_remove_device(struct kcs_bmc_device *kcs_bmc)107{108 struct kcs_bmc_serio *priv = NULL, *pos;109 110 spin_lock_irq(&kcs_bmc_serio_instances_lock);111 list_for_each_entry(pos, &kcs_bmc_serio_instances, entry) {112 if (pos->client.dev == kcs_bmc) {113 priv = pos;114 list_del(&pos->entry);115 break;116 }117 }118 spin_unlock_irq(&kcs_bmc_serio_instances_lock);119 120 if (!priv)121 return -ENODEV;122 123 /* kfree()s priv->port via put_device() */124 serio_unregister_port(priv->port);125 126 /* Ensure the IBF IRQ is disabled if we were the active client */127 kcs_bmc_disable_device(kcs_bmc, &priv->client);128 129 devm_kfree(priv->client.dev->dev, priv);130 131 return 0;132}133 134static const struct kcs_bmc_driver_ops kcs_bmc_serio_driver_ops = {135 .add_device = kcs_bmc_serio_add_device,136 .remove_device = kcs_bmc_serio_remove_device,137};138 139static struct kcs_bmc_driver kcs_bmc_serio_driver = {140 .ops = &kcs_bmc_serio_driver_ops,141};142 143static int __init kcs_bmc_serio_init(void)144{145 kcs_bmc_register_driver(&kcs_bmc_serio_driver);146 147 return 0;148}149module_init(kcs_bmc_serio_init);150 151static void __exit kcs_bmc_serio_exit(void)152{153 kcs_bmc_unregister_driver(&kcs_bmc_serio_driver);154}155module_exit(kcs_bmc_serio_exit);156 157MODULE_LICENSE("GPL v2");158MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");159MODULE_DESCRIPTION("Adapter driver for serio access to BMC KCS devices");160