// SPDX-License-Identifier: GPL-2.0-or-later

/*
 * IBM ASM Service Processor Device Driver
 *
 * Copyright (C) IBM Corporation, 2004
 *
 * Author: Max Asböck <amax@us.ibm.com>
 *
 * This driver is based on code originally written by Pete Reynolds
 * and others.
 */

/*
 * The ASM device driver does the following things:
 *
 * 1) When loaded it sends a message to the service processor,
 * indicating that an OS is * running. This causes the service processor
 * to send periodic heartbeats to the OS.
 *
 * 2) Answers the periodic heartbeats sent by the service processor.
 * Failure to do so would result in system reboot.
 *
 * 3) Acts as a pass through for dot commands sent from user applications.
 * The interface for this is the ibmasmfs file system.
 *
 * 4) Allows user applications to register for event notification. Events
 * are sent to the driver through interrupts. They can be read from user
 * space through the ibmasmfs file system.
 *
 * 5) Allows user space applications to send heartbeats to the service
 * processor (aka reverse heartbeats). Again this happens through ibmasmfs.
 *
 * 6) Handles remote mouse and keyboard event interrupts and makes them
 * available to user applications through ibmasmfs.
 *
 */

#include <linux/pci.h>
#include <linux/init.h>
#include <linux/slab.h>
#include "ibmasm.h"
#include "lowlevel.h"
#include "remote.h"

int ibmasm_debug = 0;
module_param(ibmasm_debug, int , S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(ibmasm_debug, " Set debug mode on or off");


static int ibmasm_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
        int result;
        struct service_processor *sp;

        if ((result = pci_enable_device(pdev))) {
                dev_err(&pdev->dev, "Failed to enable PCI device\n");
                return result;
        }
        if ((result = pci_request_regions(pdev, DRIVER_NAME))) {
                dev_err(&pdev->dev, "Failed to allocate PCI resources\n");
                goto error_resources;
        }
        /* vnc client won't work without bus-mastering */
        pci_set_master(pdev);

        sp = kzalloc(sizeof(struct service_processor), GFP_KERNEL);
        if (sp == NULL) {
                dev_err(&pdev->dev, "Failed to allocate memory\n");
                result = -ENOMEM;
                goto error_kmalloc;
        }

        spin_lock_init(&sp->lock);
        INIT_LIST_HEAD(&sp->command_queue);

        pci_set_drvdata(pdev, (void *)sp);
        sp->dev = &pdev->dev;
        sp->number = pdev->bus->number;
        snprintf(sp->dirname, IBMASM_NAME_SIZE, "%d", sp->number);
        snprintf(sp->devname, IBMASM_NAME_SIZE, "%s%d", DRIVER_NAME, sp->number);

        result = ibmasm_event_buffer_init(sp);
        if (result) {
                dev_err(sp->dev, "Failed to allocate event buffer\n");
                goto error_eventbuffer;
        }

        result = ibmasm_heartbeat_init(sp);
        if (result) {
                dev_err(sp->dev, "Failed to allocate heartbeat command\n");
                goto error_heartbeat;
        }

        sp->irq = pdev->irq;
        sp->base_address = pci_ioremap_bar(pdev, 0);
        if (!sp->base_address) {
                dev_err(sp->dev, "Failed to ioremap pci memory\n");
                result =  -ENODEV;
                goto error_ioremap;
        }

        result = request_irq(sp->irq, ibmasm_interrupt_handler, IRQF_SHARED, sp->devname, (void*)sp);
        if (result) {
                dev_err(sp->dev, "Failed to register interrupt handler\n");
                goto error_request_irq;
        }

        enable_sp_interrupts(sp->base_address);

        result = ibmasm_init_remote_input_dev(sp);
        if (result) {
                dev_err(sp->dev, "Failed to initialize remote queue\n");
                goto error_init_remote;
        }

        result = ibmasm_send_driver_vpd(sp);
        if (result) {
                dev_err(sp->dev, "Failed to send driver VPD to service processor\n");
                goto error_send_message;
        }
        result = ibmasm_send_os_state(sp, SYSTEM_STATE_OS_UP);
        if (result) {
                dev_err(sp->dev, "Failed to send OS state to service processor\n");
                goto error_send_message;
        }
        ibmasmfs_add_sp(sp);

        ibmasm_register_uart(sp);

        return 0;

error_send_message:
        ibmasm_free_remote_input_dev(sp);
error_init_remote:
        disable_sp_interrupts(sp->base_address);
        free_irq(sp->irq, (void *)sp);
error_request_irq:
        iounmap(sp->base_address);
error_ioremap:
        ibmasm_heartbeat_exit(sp);
error_heartbeat:
        ibmasm_event_buffer_exit(sp);
error_eventbuffer:
        kfree(sp);
error_kmalloc:
        pci_release_regions(pdev);
error_resources:
        pci_disable_device(pdev);

        return result;
}

static void ibmasm_remove_one(struct pci_dev *pdev)
{
        struct service_processor *sp = pci_get_drvdata(pdev);

        dbg("Unregistering UART\n");
        ibmasm_unregister_uart(sp);
        dbg("Sending OS down message\n");
        if (ibmasm_send_os_state(sp, SYSTEM_STATE_OS_DOWN))
                err("failed to get response to 'Send OS State' command\n");
        dbg("Disabling heartbeats\n");
        ibmasm_heartbeat_exit(sp);
        dbg("Disabling interrupts\n");
        disable_sp_interrupts(sp->base_address);
        dbg("Freeing SP irq\n");
        free_irq(sp->irq, (void *)sp);
        dbg("Cleaning up\n");
        ibmasm_free_remote_input_dev(sp);
        iounmap(sp->base_address);
        ibmasm_event_buffer_exit(sp);
        kfree(sp);
        pci_release_regions(pdev);
        pci_disable_device(pdev);
}

static struct pci_device_id ibmasm_pci_table[] =
{
        { PCI_DEVICE(VENDORID_IBM, DEVICEID_RSA) },
        {},
};

static struct pci_driver ibmasm_driver = {
        .name           = DRIVER_NAME,
        .id_table       = ibmasm_pci_table,
        .probe          = ibmasm_init_one,
        .remove         = ibmasm_remove_one,
};

static void __exit ibmasm_exit (void)
{
        ibmasm_unregister_panic_notifier();
        ibmasmfs_unregister();
        pci_unregister_driver(&ibmasm_driver);
        info(DRIVER_DESC " version " DRIVER_VERSION " unloaded");
}

static int __init ibmasm_init(void)
{
        int result = pci_register_driver(&ibmasm_driver);
        if (result)
                return result;

        result = ibmasmfs_register();
        if (result) {
                pci_unregister_driver(&ibmasm_driver);
                err("Failed to register ibmasmfs file system");
                return result;
        }

        ibmasm_register_panic_notifier();
        info(DRIVER_DESC " version " DRIVER_VERSION " loaded");
        return 0;
}

module_init(ibmasm_init);
module_exit(ibmasm_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, ibmasm_pci_table);