pci/hotplug/cpcihp_generic.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * cpcihp_generic.c
0004  *
0005  * Generic port I/O CompactPCI driver
0006  *
0007  * Copyright 2002 SOMA Networks, Inc.
0008  * Copyright 2001 Intel San Luis Obispo
0009  * Copyright 2000,2001 MontaVista Software Inc.
0010  *
0011  * This generic CompactPCI hotplug driver should allow using the PCI hotplug
0012  * mechanism on any CompactPCI board that exposes the #ENUM signal as a bit
0013  * in a system register that can be read through standard port I/O.
0014  *
0015  * Send feedback to <scottm@somanetworks.com>
0016  */
0017
0018 #include <linux/module.h>
0019 #include <linux/init.h>
0020 #include <linux/errno.h>
0021 #include <linux/pci.h>
0022 #include <linux/string.h>
0023 #include "cpci_hotplug.h"
0024
0025 #define DRIVER_VERSION  "0.1"
0026 #define DRIVER_AUTHOR   "Scott Murray <scottm@somanetworks.com>"
0027 #define DRIVER_DESC "Generic port I/O CompactPCI Hot Plug Driver"
0028
0029 #if !defined(MODULE)
0030 #define MY_NAME "cpcihp_generic"
0031 #else
0032 #define MY_NAME THIS_MODULE->name
0033 #endif
0034
0035 #define dbg(format, arg...)                 \
0036     do {                            \
0037         if (debug)                  \
0038             printk(KERN_DEBUG "%s: " format "\n",   \
0039                 MY_NAME, ## arg);       \
0040     } while (0)
0041 #define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)
0042 #define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)
0043 #define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)
0044
0045 /* local variables */
0046 static bool debug;
0047 static char *bridge;
0048 static u8 bridge_busnr;
0049 static u8 bridge_slot;
0050 static struct pci_bus *bus;
0051 static u8 first_slot;
0052 static u8 last_slot;
0053 static u16 port;
0054 static unsigned int enum_bit;
0055 static u8 enum_mask;
0056
0057 static struct cpci_hp_controller_ops generic_hpc_ops;
0058 static struct cpci_hp_controller generic_hpc;
0059
0060 static int __init validate_parameters(void)
0061 {
0062     char *str;
0063     char *p;
0064     unsigned long tmp;
0065
0066     if (!bridge) {
0067         info("not configured, disabling.");
0068         return -EINVAL;
0069     }
0070     str = bridge;
0071     if (!*str)
0072         return -EINVAL;
0073
0074     tmp = simple_strtoul(str, &p, 16);
0075     if (p == str || tmp > 0xff) {
0076         err("Invalid hotplug bus bridge device bus number");
0077         return -EINVAL;
0078     }
0079     bridge_busnr = (u8) tmp;
0080     dbg("bridge_busnr = 0x%02x", bridge_busnr);
0081     if (*p != ':') {
0082         err("Invalid hotplug bus bridge device");
0083         return -EINVAL;
0084     }
0085     str = p + 1;
0086     tmp = simple_strtoul(str, &p, 16);
0087     if (p == str || tmp > 0x1f) {
0088         err("Invalid hotplug bus bridge device slot number");
0089         return -EINVAL;
0090     }
0091     bridge_slot = (u8) tmp;
0092     dbg("bridge_slot = 0x%02x", bridge_slot);
0093
0094     dbg("first_slot = 0x%02x", first_slot);
0095     dbg("last_slot = 0x%02x", last_slot);
0096     if (!(first_slot && last_slot)) {
0097         err("Need to specify first_slot and last_slot");
0098         return -EINVAL;
0099     }
0100     if (last_slot < first_slot) {
0101         err("first_slot must be less than last_slot");
0102         return -EINVAL;
0103     }
0104
0105     dbg("port = 0x%04x", port);
0106     dbg("enum_bit = 0x%02x", enum_bit);
0107     if (enum_bit > 7) {
0108         err("Invalid #ENUM bit");
0109         return -EINVAL;
0110     }
0111     enum_mask = 1 << enum_bit;
0112     return 0;
0113 }
0114
0115 static int query_enum(void)
0116 {
0117     u8 value;
0118
0119     value = inb_p(port);
0120     return ((value & enum_mask) == enum_mask);
0121 }
0122
0123 static int __init cpcihp_generic_init(void)
0124 {
0125     int status;
0126     struct resource *r;
0127     struct pci_dev *dev;
0128
0129     info(DRIVER_DESC " version: " DRIVER_VERSION);
0130     status = validate_parameters();
0131     if (status)
0132         return status;
0133
0134     r = request_region(port, 1, "#ENUM hotswap signal register");
0135     if (!r)
0136         return -EBUSY;
0137
0138     dev = pci_get_domain_bus_and_slot(0, bridge_busnr,
0139                       PCI_DEVFN(bridge_slot, 0));
0140     if (!dev || dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
0141         err("Invalid bridge device %s", bridge);
0142         pci_dev_put(dev);
0143         return -EINVAL;
0144     }
0145     bus = dev->subordinate;
0146     pci_dev_put(dev);
0147
0148     memset(&generic_hpc, 0, sizeof(struct cpci_hp_controller));
0149     generic_hpc_ops.query_enum = query_enum;
0150     generic_hpc.ops = &generic_hpc_ops;
0151
0152     status = cpci_hp_register_controller(&generic_hpc);
0153     if (status != 0) {
0154         err("Could not register cPCI hotplug controller");
0155         return -ENODEV;
0156     }
0157     dbg("registered controller");
0158
0159     status = cpci_hp_register_bus(bus, first_slot, last_slot);
0160     if (status != 0) {
0161         err("Could not register cPCI hotplug bus");
0162         goto init_bus_register_error;
0163     }
0164     dbg("registered bus");
0165
0166     status = cpci_hp_start();
0167     if (status != 0) {
0168         err("Could not started cPCI hotplug system");
0169         goto init_start_error;
0170     }
0171     dbg("started cpci hp system");
0172     return 0;
0173 init_start_error:
0174     cpci_hp_unregister_bus(bus);
0175 init_bus_register_error:
0176     cpci_hp_unregister_controller(&generic_hpc);
0177     err("status = %d", status);
0178     return status;
0179
0180 }
0181
0182 static void __exit cpcihp_generic_exit(void)
0183 {
0184     cpci_hp_stop();
0185     cpci_hp_unregister_bus(bus);
0186     cpci_hp_unregister_controller(&generic_hpc);
0187     release_region(port, 1);
0188 }
0189
0190 module_init(cpcihp_generic_init);
0191 module_exit(cpcihp_generic_exit);
0192
0193 MODULE_AUTHOR(DRIVER_AUTHOR);
0194 MODULE_DESCRIPTION(DRIVER_DESC);
0195 MODULE_LICENSE("GPL");
0196 module_param(debug, bool, S_IRUGO | S_IWUSR);
0197 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
0198 module_param(bridge, charp, 0);
0199 MODULE_PARM_DESC(bridge, "Hotswap bus bridge device, <bus>:<slot> (bus and slot are in hexadecimal)");
0200 module_param(first_slot, byte, 0);
0201 MODULE_PARM_DESC(first_slot, "Hotswap bus first slot number");
0202 module_param(last_slot, byte, 0);
0203 MODULE_PARM_DESC(last_slot, "Hotswap bus last slot number");
0204 module_param_hw(port, ushort, ioport, 0);
0205 MODULE_PARM_DESC(port, "#ENUM signal I/O port");
0206 module_param(enum_bit, uint, 0);
0207 MODULE_PARM_DESC(enum_bit, "#ENUM signal bit (0-7)");