drivers/pci/hotplug/cpcihp_generic.c

   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 */
  46 static bool debug;
  47 static char *bridge;
  48 static u8 bridge_busnr;
  49 static u8 bridge_slot;
  50 static struct pci_bus *bus;
  51 static u8 first_slot;
  52 static u8 last_slot;
  53 static u16 port;
  54 static unsigned int enum_bit;
  55 static u8 enum_mask;
  56
  57 static struct cpci_hp_controller_ops generic_hpc_ops;
  58 static struct cpci_hp_controller generic_hpc;
  59
  60 static 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
 115 static int query_enum(void)
 116 {
 117         u8 value;
 118
 119         value = inb_p(port);
 120         return ((value & enum_mask) == enum_mask);
 121 }
 122
 123 static 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;
 173 init_start_error:
 174         cpci_hp_unregister_bus(bus);
 175 init_bus_register_error:
 176         cpci_hp_unregister_controller(&generic_hpc);
 177         err("status = %d", status);
 178         return status;
 179
 180 }
 181
 182 static 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
 190 module_init(cpcihp_generic_init);
 191 module_exit(cpcihp_generic_exit);
 192
 193 MODULE_AUTHOR(DRIVER_AUTHOR);
 194 MODULE_DESCRIPTION(DRIVER_DESC);
 195 MODULE_LICENSE("GPL");
 196 module_param(debug, bool, S_IRUGO | S_IWUSR);
 197 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
 198 module_param(bridge, charp, 0);
 199 MODULE_PARM_DESC(bridge, "Hotswap bus bridge device, <bus>:<slot> (bus and slot are in hexadecimal)");
 200 module_param(first_slot, byte, 0);
 201 MODULE_PARM_DESC(first_slot, "Hotswap bus first slot number");
 202 module_param(last_slot, byte, 0);
 203 MODULE_PARM_DESC(last_slot, "Hotswap bus last slot number");
 204 module_param_hw(port, ushort, ioport, 0);
 205 MODULE_PARM_DESC(port, "#ENUM signal I/O port");
 206 module_param(enum_bit, uint, 0);
 207 MODULE_PARM_DESC(enum_bit, "#ENUM signal bit (0-7)");