linux/drivers/pci/hotplug/cpcihp_generic.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * cpcihp_generic.c
   4 *
   5 * Generic port I/O CompactPCI driver
   6 *
   7 * Copyright 2002 SOMA Networks, Inc.
   8 * Copyright 2001 Intel San Luis Obispo
   9 * Copyright 2000,2001 MontaVista Software Inc.
  10 *
  11 * This generic CompactPCI hotplug driver should allow using the PCI hotplug
  12 * mechanism on any CompactPCI board that exposes the #ENUM signal as a bit
  13 * in a system register that can be read through standard port I/O.
  14 *
  15 * Send feedback to <scottm@somanetworks.com>
  16 */
  17
  18#include <linux/module.h>
  19#include <linux/init.h>
  20#include <linux/errno.h>
  21#include <linux/pci.h>
  22#include <linux/string.h>
  23#include "cpci_hotplug.h"
  24
  25#define DRIVER_VERSION  "0.1"
  26#define DRIVER_AUTHOR   "Scott Murray <scottm@somanetworks.com>"
  27#define DRIVER_DESC     "Generic port I/O CompactPCI Hot Plug Driver"
  28
  29#if !defined(MODULE)
  30#define MY_NAME "cpcihp_generic"
  31#else
  32#define MY_NAME THIS_MODULE->name
  33#endif
  34
  35#define dbg(format, arg...)                                     \
  36        do {                                                    \
  37                if (debug)                                      \
  38                        printk(KERN_DEBUG "%s: " format "\n",   \
  39                                MY_NAME, ## arg);               \
  40        } while (0)
  41#define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)
  42#define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)
  43#define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)
  44
  45/* local variables */
  46static bool debug;
  47static char *bridge;
  48static u8 bridge_busnr;
  49static u8 bridge_slot;
  50static struct pci_bus *bus;
  51static u8 first_slot;
  52static u8 last_slot;
  53static u16 port;
  54static unsigned int enum_bit;
  55static u8 enum_mask;
  56
  57static struct cpci_hp_controller_ops generic_hpc_ops;
  58static struct cpci_hp_controller generic_hpc;
  59
  60static int __init validate_parameters(void)
  61{
  62        char *str;
  63        char *p;
  64        unsigned long tmp;
  65
  66        if (!bridge) {
  67                info("not configured, disabling.");
  68                return -EINVAL;
  69        }
  70        str = bridge;
  71        if (!*str)
  72                return -EINVAL;
  73
  74        tmp = simple_strtoul(str, &p, 16);
  75        if (p == str || tmp > 0xff) {
  76                err("Invalid hotplug bus bridge device bus number");
  77                return -EINVAL;
  78        }
  79        bridge_busnr = (u8) tmp;
  80        dbg("bridge_busnr = 0x%02x", bridge_busnr);
  81        if (*p != ':') {
  82                err("Invalid hotplug bus bridge device");
  83                return -EINVAL;
  84        }
  85        str = p + 1;
  86        tmp = simple_strtoul(str, &p, 16);
  87        if (p == str || tmp > 0x1f) {
  88                err("Invalid hotplug bus bridge device slot number");
  89                return -EINVAL;
  90        }
  91        bridge_slot = (u8) tmp;
  92        dbg("bridge_slot = 0x%02x", bridge_slot);
  93
  94        dbg("first_slot = 0x%02x", first_slot);
  95        dbg("last_slot = 0x%02x", last_slot);
  96        if (!(first_slot && last_slot)) {
  97                err("Need to specify first_slot and last_slot");
  98                return -EINVAL;
  99        }
 100        if (last_slot < first_slot) {
 101                err("first_slot must be less than last_slot");
 102                return -EINVAL;
 103        }
 104
 105        dbg("port = 0x%04x", port);
 106        dbg("enum_bit = 0x%02x", enum_bit);
 107        if (enum_bit > 7) {
 108                err("Invalid #ENUM bit");
 109                return -EINVAL;
 110        }
 111        enum_mask = 1 << enum_bit;
 112        return 0;
 113}
 114
 115static int query_enum(void)
 116{
 117        u8 value;
 118
 119        value = inb_p(port);
 120        return ((value & enum_mask) == enum_mask);
 121}
 122
 123static int __init cpcihp_generic_init(void)
 124{
 125        int status;
 126        struct resource *r;
 127        struct pci_dev *dev;
 128
 129        info(DRIVER_DESC " version: " DRIVER_VERSION);
 130        status = validate_parameters();
 131        if (status)
 132                return status;
 133
 134        r = request_region(port, 1, "#ENUM hotswap signal register");
 135        if (!r)
 136                return -EBUSY;
 137
 138        dev = pci_get_domain_bus_and_slot(0, bridge_busnr,
 139                                          PCI_DEVFN(bridge_slot, 0));
 140        if (!dev || dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
 141                err("Invalid bridge device %s", bridge);
 142                pci_dev_put(dev);
 143                return -EINVAL;
 144        }
 145        bus = dev->subordinate;
 146        pci_dev_put(dev);
 147
 148        memset(&generic_hpc, 0, sizeof(struct cpci_hp_controller));
 149        generic_hpc_ops.query_enum = query_enum;
 150        generic_hpc.ops = &generic_hpc_ops;
 151
 152        status = cpci_hp_register_controller(&generic_hpc);
 153        if (status != 0) {
 154                err("Could not register cPCI hotplug controller");
 155                return -ENODEV;
 156        }
 157        dbg("registered controller");
 158
 159        status = cpci_hp_register_bus(bus, first_slot, last_slot);
 160        if (status != 0) {
 161                err("Could not register cPCI hotplug bus");
 162                goto init_bus_register_error;
 163        }
 164        dbg("registered bus");
 165
 166        status = cpci_hp_start();
 167        if (status != 0) {
 168                err("Could not started cPCI hotplug system");
 169                goto init_start_error;
 170        }
 171        dbg("started cpci hp system");
 172        return 0;
 173init_start_error:
 174        cpci_hp_unregister_bus(bus);
 175init_bus_register_error:
 176        cpci_hp_unregister_controller(&generic_hpc);
 177        err("status = %d", status);
 178        return status;
 179
 180}
 181
 182static void __exit cpcihp_generic_exit(void)
 183{
 184        cpci_hp_stop();
 185        cpci_hp_unregister_bus(bus);
 186        cpci_hp_unregister_controller(&generic_hpc);
 187        release_region(port, 1);
 188}
 189
 190module_init(cpcihp_generic_init);
 191module_exit(cpcihp_generic_exit);
 192
 193MODULE_AUTHOR(DRIVER_AUTHOR);
 194MODULE_DESCRIPTION(DRIVER_DESC);
 195MODULE_LICENSE("GPL");
 196module_param(debug, bool, S_IRUGO | S_IWUSR);
 197MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
 198module_param(bridge, charp, 0);
 199MODULE_PARM_DESC(bridge, "Hotswap bus bridge device, <bus>:<slot> (bus and slot are in hexadecimal)");
 200module_param(first_slot, byte, 0);
 201MODULE_PARM_DESC(first_slot, "Hotswap bus first slot number");
 202module_param(last_slot, byte, 0);
 203MODULE_PARM_DESC(last_slot, "Hotswap bus last slot number");
 204module_param_hw(port, ushort, ioport, 0);
 205MODULE_PARM_DESC(port, "#ENUM signal I/O port");
 206module_param(enum_bit, uint, 0);
 207MODULE_PARM_DESC(enum_bit, "#ENUM signal bit (0-7)");
 208