// SPDX-License-Identifier: GPL-2.0+
/*
 * CompactPCI Hot Plug Driver PCI functions
 *
 * Copyright (C) 2002,2005 by SOMA Networks, Inc.
 *
 * All rights reserved.
 *
 * Send feedback to <scottm@somanetworks.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/proc_fs.h>
#include "../pci.h"
#include "cpci_hotplug.h"

#define MY_NAME "cpci_hotplug"

#define dbg(format, arg...)                                     \
        do {                                                    \
                if (cpci_debug)                                 \
                        printk(KERN_DEBUG "%s: " format "\n",   \
                                MY_NAME, ## arg);               \
        } while (0)
#define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)
#define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)
#define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)


u8 cpci_get_attention_status(struct slot *slot)
{
        int hs_cap;
        u16 hs_csr;

        hs_cap = pci_bus_find_capability(slot->bus,
                                         slot->devfn,
                                         PCI_CAP_ID_CHSWP);
        if (!hs_cap)
                return 0;

        if (pci_bus_read_config_word(slot->bus,
                                     slot->devfn,
                                     hs_cap + 2,
                                     &hs_csr))
                return 0;

        return hs_csr & 0x0008 ? 1 : 0;
}

int cpci_set_attention_status(struct slot *slot, int status)
{
        int hs_cap;
        u16 hs_csr;

        hs_cap = pci_bus_find_capability(slot->bus,
                                         slot->devfn,
                                         PCI_CAP_ID_CHSWP);
        if (!hs_cap)
                return 0;
        if (pci_bus_read_config_word(slot->bus,
                                     slot->devfn,
                                     hs_cap + 2,
                                     &hs_csr))
                return 0;
        if (status)
                hs_csr |= HS_CSR_LOO;
        else
                hs_csr &= ~HS_CSR_LOO;
        if (pci_bus_write_config_word(slot->bus,
                                      slot->devfn,
                                      hs_cap + 2,
                                      hs_csr))
                return 0;
        return 1;
}

u16 cpci_get_hs_csr(struct slot *slot)
{
        int hs_cap;
        u16 hs_csr;

        hs_cap = pci_bus_find_capability(slot->bus,
                                         slot->devfn,
                                         PCI_CAP_ID_CHSWP);
        if (!hs_cap)
                return 0xFFFF;
        if (pci_bus_read_config_word(slot->bus,
                                     slot->devfn,
                                     hs_cap + 2,
                                     &hs_csr))
                return 0xFFFF;
        return hs_csr;
}

int cpci_check_and_clear_ins(struct slot *slot)
{
        int hs_cap;
        u16 hs_csr;
        int ins = 0;

        hs_cap = pci_bus_find_capability(slot->bus,
                                         slot->devfn,
                                         PCI_CAP_ID_CHSWP);
        if (!hs_cap)
                return 0;
        if (pci_bus_read_config_word(slot->bus,
                                     slot->devfn,
                                     hs_cap + 2,
                                     &hs_csr))
                return 0;
        if (hs_csr & HS_CSR_INS) {
                /* Clear INS (by setting it) */
                if (pci_bus_write_config_word(slot->bus,
                                              slot->devfn,
                                              hs_cap + 2,
                                              hs_csr))
                        ins = 0;
                else
                        ins = 1;
        }
        return ins;
}

int cpci_check_ext(struct slot *slot)
{
        int hs_cap;
        u16 hs_csr;
        int ext = 0;

        hs_cap = pci_bus_find_capability(slot->bus,
                                         slot->devfn,
                                         PCI_CAP_ID_CHSWP);
        if (!hs_cap)
                return 0;
        if (pci_bus_read_config_word(slot->bus,
                                     slot->devfn,
                                     hs_cap + 2,
                                     &hs_csr))
                return 0;
        if (hs_csr & HS_CSR_EXT)
                ext = 1;
        return ext;
}

int cpci_clear_ext(struct slot *slot)
{
        int hs_cap;
        u16 hs_csr;

        hs_cap = pci_bus_find_capability(slot->bus,
                                         slot->devfn,
                                         PCI_CAP_ID_CHSWP);
        if (!hs_cap)
                return -ENODEV;
        if (pci_bus_read_config_word(slot->bus,
                                     slot->devfn,
                                     hs_cap + 2,
                                     &hs_csr))
                return -ENODEV;
        if (hs_csr & HS_CSR_EXT) {
                /* Clear EXT (by setting it) */
                if (pci_bus_write_config_word(slot->bus,
                                              slot->devfn,
                                              hs_cap + 2,
                                              hs_csr))
                        return -ENODEV;
        }
        return 0;
}

int cpci_led_on(struct slot *slot)
{
        int hs_cap;
        u16 hs_csr;

        hs_cap = pci_bus_find_capability(slot->bus,
                                         slot->devfn,
                                         PCI_CAP_ID_CHSWP);
        if (!hs_cap)
                return -ENODEV;
        if (pci_bus_read_config_word(slot->bus,
                                     slot->devfn,
                                     hs_cap + 2,
                                     &hs_csr))
                return -ENODEV;
        if ((hs_csr & HS_CSR_LOO) != HS_CSR_LOO) {
                hs_csr |= HS_CSR_LOO;
                if (pci_bus_write_config_word(slot->bus,
                                              slot->devfn,
                                              hs_cap + 2,
                                              hs_csr)) {
                        err("Could not set LOO for slot %s", slot_name(slot));
                        return -ENODEV;
                }
        }
        return 0;
}

int cpci_led_off(struct slot *slot)
{
        int hs_cap;
        u16 hs_csr;

        hs_cap = pci_bus_find_capability(slot->bus,
                                         slot->devfn,
                                         PCI_CAP_ID_CHSWP);
        if (!hs_cap)
                return -ENODEV;
        if (pci_bus_read_config_word(slot->bus,
                                     slot->devfn,
                                     hs_cap + 2,
                                     &hs_csr))
                return -ENODEV;
        if (hs_csr & HS_CSR_LOO) {
                hs_csr &= ~HS_CSR_LOO;
                if (pci_bus_write_config_word(slot->bus,
                                              slot->devfn,
                                              hs_cap + 2,
                                              hs_csr)) {
                        err("Could not clear LOO for slot %s", slot_name(slot));
                        return -ENODEV;
                }
        }
        return 0;
}


/*
 * Device configuration functions
 */

int cpci_configure_slot(struct slot *slot)
{
        struct pci_dev *dev;
        struct pci_bus *parent;
        int ret = 0;

        dbg("%s - enter", __func__);

        pci_lock_rescan_remove();

        if (slot->dev == NULL) {
                dbg("pci_dev null, finding %02x:%02x:%x",
                    slot->bus->number, PCI_SLOT(slot->devfn), PCI_FUNC(slot->devfn));
                slot->dev = pci_get_slot(slot->bus, slot->devfn);
        }

        /* Still NULL? Well then scan for it! */
        if (slot->dev == NULL) {
                int n;
                dbg("pci_dev still null");

                /*
                 * This will generate pci_dev structures for all functions, but
                 * we will only call this case when lookup fails.
                 */
                n = pci_scan_slot(slot->bus, slot->devfn);
                dbg("%s: pci_scan_slot returned %d", __func__, n);
                slot->dev = pci_get_slot(slot->bus, slot->devfn);
                if (slot->dev == NULL) {
                        err("Could not find PCI device for slot %02x", slot->number);
                        ret = -ENODEV;
                        goto out;
                }
        }
        parent = slot->dev->bus;

        for_each_pci_bridge(dev, parent) {
                if (PCI_SLOT(dev->devfn) == PCI_SLOT(slot->devfn))
                        pci_hp_add_bridge(dev);
        }

        pci_assign_unassigned_bridge_resources(parent->self);

        pci_bus_add_devices(parent);

 out:
        pci_unlock_rescan_remove();
        dbg("%s - exit", __func__);
        return ret;
}

int cpci_unconfigure_slot(struct slot *slot)
{
        struct pci_dev *dev, *temp;

        dbg("%s - enter", __func__);
        if (!slot->dev) {
                err("No device for slot %02x\n", slot->number);
                return -ENODEV;
        }

        pci_lock_rescan_remove();

        list_for_each_entry_safe(dev, temp, &slot->bus->devices, bus_list) {
                if (PCI_SLOT(dev->devfn) != PCI_SLOT(slot->devfn))
                        continue;
                pci_dev_get(dev);
                pci_stop_and_remove_bus_device(dev);
                pci_dev_put(dev);
        }
        pci_dev_put(slot->dev);
        slot->dev = NULL;

        pci_unlock_rescan_remove();

        dbg("%s - exit", __func__);
        return 0;
}