Samuel Iglesias Gonsalvez | d346587 | 2012-05-09 15:27:19 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * Industry-pack bus support functions. |
| 3 | * |
| 4 | * (C) 2011 Samuel Iglesias Gonsalvez <siglesia@cern.ch>, CERN |
| 5 | * (C) 2012 Samuel Iglesias Gonsalvez <siglesias@igalia.com>, Igalia |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify it |
| 8 | * under the terms of the GNU General Public License as published by the Free |
| 9 | * Software Foundation; either version 2 of the License, or (at your option) |
| 10 | * any later version. |
| 11 | */ |
| 12 | |
| 13 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 14 | |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/mutex.h> |
| 17 | #include "ipack.h" |
| 18 | |
| 19 | #define to_ipack_dev(device) container_of(device, struct ipack_device, dev) |
| 20 | #define to_ipack_driver(drv) container_of(drv, struct ipack_driver, driver) |
| 21 | |
| 22 | /* used when allocating bus numbers */ |
| 23 | #define IPACK_MAXBUS 64 |
| 24 | |
| 25 | static DEFINE_MUTEX(ipack_mutex); |
| 26 | |
| 27 | struct ipack_busmap { |
| 28 | unsigned long busmap[IPACK_MAXBUS / (8*sizeof(unsigned long))]; |
| 29 | }; |
| 30 | static struct ipack_busmap busmap; |
| 31 | |
| 32 | static int ipack_bus_match(struct device *device, struct device_driver *driver) |
| 33 | { |
| 34 | int ret; |
| 35 | struct ipack_device *dev = to_ipack_dev(device); |
| 36 | struct ipack_driver *drv = to_ipack_driver(driver); |
| 37 | |
| 38 | if (!drv->ops->match) |
| 39 | return -EINVAL; |
| 40 | |
| 41 | ret = drv->ops->match(dev); |
| 42 | if (ret) |
| 43 | dev->driver = drv; |
| 44 | |
| 45 | return 0; |
| 46 | } |
| 47 | |
| 48 | static int ipack_bus_probe(struct device *device) |
| 49 | { |
| 50 | struct ipack_device *dev = to_ipack_dev(device); |
| 51 | |
| 52 | if (!dev->driver->ops->probe) |
| 53 | return -EINVAL; |
| 54 | |
| 55 | return dev->driver->ops->probe(dev); |
| 56 | } |
| 57 | |
| 58 | static int ipack_bus_remove(struct device *device) |
| 59 | { |
| 60 | struct ipack_device *dev = to_ipack_dev(device); |
| 61 | |
| 62 | if (!dev->driver->ops->remove) |
| 63 | return -EINVAL; |
| 64 | |
| 65 | dev->driver->ops->remove(dev); |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | static struct bus_type ipack_bus_type = { |
| 70 | .name = "ipack", |
| 71 | .probe = ipack_bus_probe, |
| 72 | .match = ipack_bus_match, |
| 73 | .remove = ipack_bus_remove, |
| 74 | }; |
| 75 | |
| 76 | static int ipack_assign_bus_number(void) |
| 77 | { |
| 78 | int busnum; |
| 79 | |
| 80 | mutex_lock(&ipack_mutex); |
| 81 | busnum = find_next_zero_bit(busmap.busmap, IPACK_MAXBUS, 1); |
| 82 | |
| 83 | if (busnum >= IPACK_MAXBUS) { |
| 84 | pr_err("too many buses\n"); |
| 85 | busnum = -1; |
| 86 | goto error_find_busnum; |
| 87 | } |
| 88 | |
| 89 | set_bit(busnum, busmap.busmap); |
| 90 | |
| 91 | error_find_busnum: |
| 92 | mutex_unlock(&ipack_mutex); |
| 93 | return busnum; |
| 94 | } |
| 95 | |
| 96 | int ipack_bus_register(struct ipack_bus_device *bus) |
| 97 | { |
| 98 | int bus_nr; |
| 99 | |
| 100 | bus_nr = ipack_assign_bus_number(); |
| 101 | if (bus_nr < 0) |
| 102 | return -1; |
| 103 | |
| 104 | bus->bus_nr = bus_nr; |
| 105 | return 0; |
| 106 | } |
| 107 | EXPORT_SYMBOL_GPL(ipack_bus_register); |
| 108 | |
| 109 | int ipack_bus_unregister(struct ipack_bus_device *bus) |
| 110 | { |
| 111 | mutex_lock(&ipack_mutex); |
| 112 | clear_bit(bus->bus_nr, busmap.busmap); |
| 113 | mutex_unlock(&ipack_mutex); |
| 114 | return 0; |
| 115 | } |
| 116 | EXPORT_SYMBOL_GPL(ipack_bus_unregister); |
| 117 | |
| 118 | int ipack_driver_register(struct ipack_driver *edrv) |
| 119 | { |
| 120 | edrv->driver.bus = &ipack_bus_type; |
| 121 | return driver_register(&edrv->driver); |
| 122 | } |
| 123 | EXPORT_SYMBOL_GPL(ipack_driver_register); |
| 124 | |
| 125 | void ipack_driver_unregister(struct ipack_driver *edrv) |
| 126 | { |
| 127 | driver_unregister(&edrv->driver); |
| 128 | } |
| 129 | EXPORT_SYMBOL_GPL(ipack_driver_unregister); |
| 130 | |
| 131 | static void ipack_device_release(struct device *dev) |
| 132 | { |
| 133 | } |
| 134 | |
| 135 | int ipack_device_register(struct ipack_device *dev) |
| 136 | { |
| 137 | int ret; |
| 138 | |
| 139 | dev->dev.bus = &ipack_bus_type; |
| 140 | dev->dev.release = ipack_device_release; |
| 141 | dev_set_name(&dev->dev, |
| 142 | "%s.%u.%u", dev->board_name, dev->bus_nr, dev->slot); |
| 143 | |
| 144 | ret = device_register(&dev->dev); |
| 145 | if (ret < 0) { |
| 146 | pr_err("error registering the device.\n"); |
| 147 | dev->driver->ops->remove(dev); |
| 148 | } |
| 149 | |
| 150 | return ret; |
| 151 | } |
| 152 | EXPORT_SYMBOL_GPL(ipack_device_register); |
| 153 | |
| 154 | void ipack_device_unregister(struct ipack_device *dev) |
| 155 | { |
| 156 | device_unregister(&dev->dev); |
| 157 | } |
| 158 | EXPORT_SYMBOL_GPL(ipack_device_unregister); |
| 159 | |
| 160 | static int __init ipack_init(void) |
| 161 | { |
| 162 | return bus_register(&ipack_bus_type); |
| 163 | } |
| 164 | |
| 165 | static void __exit ipack_exit(void) |
| 166 | { |
| 167 | bus_unregister(&ipack_bus_type); |
| 168 | } |
| 169 | |
| 170 | module_init(ipack_init); |
| 171 | module_exit(ipack_exit); |
| 172 | |
| 173 | MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>"); |
| 174 | MODULE_LICENSE("GPL"); |
| 175 | MODULE_DESCRIPTION("Industry-pack bus core"); |