root/drivers/pci/hotplug/shpchp_core.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Standard Hot Plug Controller Driver
 *
 * Copyright (C) 1995,2001 Compaq Computer Corporation
 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (C) 2001 IBM Corp.
 * Copyright (C) 2003-2004 Intel Corporation
 *
 * All rights reserved.
 *
 * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
 *
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include "shpchp.h"

/* Global variables */
bool shpchp_poll_mode;
int shpchp_poll_time;

#define DRIVER_VERSION  "0.4"
#define DRIVER_AUTHOR   "Dan Zink <dan.zink@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
#define DRIVER_DESC     "Standard Hot Plug PCI Controller Driver"

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);

module_param(shpchp_poll_mode, bool, 0644);
module_param(shpchp_poll_time, int, 0644);
MODULE_PARM_DESC(shpchp_poll_mode, "Using polling mechanism for hot-plug events or not");
MODULE_PARM_DESC(shpchp_poll_time, "Polling mechanism frequency, in seconds");

#define SHPC_MODULE_NAME "shpchp"

static int set_attention_status(struct hotplug_slot *slot, u8 value);
static int enable_slot(struct hotplug_slot *slot);
static int disable_slot(struct hotplug_slot *slot);
static int get_power_status(struct hotplug_slot *slot, u8 *value);
static int get_attention_status(struct hotplug_slot *slot, u8 *value);
static int get_latch_status(struct hotplug_slot *slot, u8 *value);
static int get_adapter_status(struct hotplug_slot *slot, u8 *value);

static const struct hotplug_slot_ops shpchp_hotplug_slot_ops = {
        .set_attention_status = set_attention_status,
        .enable_slot =          enable_slot,
        .disable_slot =         disable_slot,
        .get_power_status =     get_power_status,
        .get_attention_status = get_attention_status,
        .get_latch_status =     get_latch_status,
        .get_adapter_status =   get_adapter_status,
};

static int init_slots(struct controller *ctrl)
{
        struct slot *slot;
        struct hotplug_slot *hotplug_slot;
        char name[SLOT_NAME_SIZE];
        int retval;
        int i;

        for (i = 0; i < ctrl->num_slots; i++) {
                slot = kzalloc_obj(*slot);
                if (!slot) {
                        retval = -ENOMEM;
                        goto error;
                }

                hotplug_slot = &slot->hotplug_slot;

                slot->hp_slot = i;
                slot->ctrl = ctrl;
                slot->bus = ctrl->pci_dev->subordinate->number;
                slot->device = ctrl->slot_device_offset + i;
                slot->number = ctrl->first_slot + (ctrl->slot_num_inc * i);

                slot->wq = alloc_workqueue("shpchp-%d", WQ_PERCPU, 0,
                                           slot->number);
                if (!slot->wq) {
                        retval = -ENOMEM;
                        goto error_slot;
                }

                mutex_init(&slot->lock);
                INIT_DELAYED_WORK(&slot->work, shpchp_queue_pushbutton_work);

                /* register this slot with the hotplug pci core */
                snprintf(name, SLOT_NAME_SIZE, "%d", slot->number);
                hotplug_slot->ops = &shpchp_hotplug_slot_ops;

                ctrl_dbg(ctrl, "Registering domain:bus:dev=%04x:%02x:%02x hp_slot=%x sun=%x slot_device_offset=%x\n",
                         pci_domain_nr(ctrl->pci_dev->subordinate),
                         slot->bus, slot->device, slot->hp_slot, slot->number,
                         ctrl->slot_device_offset);
                retval = pci_hp_register(hotplug_slot,
                                ctrl->pci_dev->subordinate, slot->device, name);
                if (retval) {
                        ctrl_err(ctrl, "pci_hp_register failed with error %d\n",
                                 retval);
                        goto error_slotwq;
                }

                get_power_status(hotplug_slot, &slot->pwr_save);
                get_attention_status(hotplug_slot, &slot->attention_save);
                get_latch_status(hotplug_slot, &slot->latch_save);
                get_adapter_status(hotplug_slot, &slot->presence_save);

                list_add(&slot->slot_list, &ctrl->slot_list);
        }

        return 0;
error_slotwq:
        destroy_workqueue(slot->wq);
error_slot:
        kfree(slot);
error:
        return retval;
}

void cleanup_slots(struct controller *ctrl)
{
        struct slot *slot, *next;

        list_for_each_entry_safe(slot, next, &ctrl->slot_list, slot_list) {
                list_del(&slot->slot_list);
                cancel_delayed_work(&slot->work);
                destroy_workqueue(slot->wq);
                pci_hp_deregister(&slot->hotplug_slot);
                kfree(slot);
        }
}

/*
 * set_attention_status - Turns the Amber LED for a slot on, off or blink
 */
static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
{
        struct slot *slot = get_slot(hotplug_slot);

        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
                 __func__, slot_name(slot));

        slot->attention_save = status;
        shpchp_set_attention_status(slot, status);

        return 0;
}

static int enable_slot(struct hotplug_slot *hotplug_slot)
{
        struct slot *slot = get_slot(hotplug_slot);

        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
                 __func__, slot_name(slot));

        return shpchp_sysfs_enable_slot(slot);
}

static int disable_slot(struct hotplug_slot *hotplug_slot)
{
        struct slot *slot = get_slot(hotplug_slot);

        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
                 __func__, slot_name(slot));

        return shpchp_sysfs_disable_slot(slot);
}

static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        struct slot *slot = get_slot(hotplug_slot);
        int retval;

        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
                 __func__, slot_name(slot));

        retval = shpchp_get_power_status(slot, value);
        if (retval < 0)
                *value = slot->pwr_save;

        return 0;
}

static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        struct slot *slot = get_slot(hotplug_slot);
        int retval;

        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
                 __func__, slot_name(slot));

        retval = shpchp_get_attention_status(slot, value);
        if (retval < 0)
                *value = slot->attention_save;

        return 0;
}

static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        struct slot *slot = get_slot(hotplug_slot);
        int retval;

        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
                 __func__, slot_name(slot));

        retval = shpchp_get_latch_status(slot, value);
        if (retval < 0)
                *value = slot->latch_save;

        return 0;
}

static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        struct slot *slot = get_slot(hotplug_slot);
        int retval;

        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
                 __func__, slot_name(slot));

        retval = shpchp_get_adapter_status(slot, value);
        if (retval < 0)
                *value = slot->presence_save;

        return 0;
}

static bool shpc_capable(struct pci_dev *bridge)
{
        /*
         * It is assumed that AMD GOLAM chips support SHPC but they do not
         * have SHPC capability.
         */
        if (bridge->vendor == PCI_VENDOR_ID_AMD &&
            bridge->device == PCI_DEVICE_ID_AMD_GOLAM_7450)
                return true;

        if (pci_find_capability(bridge, PCI_CAP_ID_SHPC))
                return true;

        return false;
}

static int shpc_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        int rc;
        struct controller *ctrl;

        if (!shpc_capable(pdev))
                return -ENODEV;

        if (acpi_get_hp_hw_control_from_firmware(pdev))
                return -ENODEV;

        ctrl = kzalloc_obj(*ctrl);
        if (!ctrl)
                goto err_out_none;

        INIT_LIST_HEAD(&ctrl->slot_list);

        rc = shpc_init(ctrl, pdev);
        if (rc) {
                ctrl_dbg(ctrl, "Controller initialization failed\n");
                goto err_out_free_ctrl;
        }

        pci_set_drvdata(pdev, ctrl);

        /* Setup the slot information structures */
        rc = init_slots(ctrl);
        if (rc) {
                ctrl_err(ctrl, "Slot initialization failed\n");
                goto err_out_release_ctlr;
        }

        rc = shpchp_create_ctrl_files(ctrl);
        if (rc)
                goto err_cleanup_slots;

        pdev->shpc_managed = 1;
        return 0;

err_cleanup_slots:
        cleanup_slots(ctrl);
err_out_release_ctlr:
        shpchp_release_ctlr(ctrl);
err_out_free_ctrl:
        kfree(ctrl);
err_out_none:
        return -ENODEV;
}

static void shpc_remove(struct pci_dev *dev)
{
        struct controller *ctrl = pci_get_drvdata(dev);

        dev->shpc_managed = 0;
        shpchp_remove_ctrl_files(ctrl);
        shpchp_release_ctlr(ctrl);
        kfree(ctrl);
}

static const struct pci_device_id shpcd_pci_tbl[] = {
        {PCI_DEVICE_CLASS(PCI_CLASS_BRIDGE_PCI_NORMAL, ~0)},
        { /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE(pci, shpcd_pci_tbl);

static struct pci_driver shpc_driver = {
        .name =         SHPC_MODULE_NAME,
        .id_table =     shpcd_pci_tbl,
        .probe =        shpc_probe,
        .remove =       shpc_remove,
};

static int __init shpcd_init(void)
{
        return pci_register_driver(&shpc_driver);
}

static void __exit shpcd_cleanup(void)
{
        pci_unregister_driver(&shpc_driver);
}

module_init(shpcd_init);
module_exit(shpcd_cleanup);