drivers/staging/comedi/comedi_pcmcia.c

   1 /*
   2  * comedi_pcmcia.c
   3  * Comedi PCMCIA driver specific functions.
   4  *
   5  * COMEDI - Linux Control and Measurement Device Interface
   6  * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21
  22 #include "comedi_pcmcia.h"
  23
  24 /**
  25  * comedi_to_pcmcia_dev() - Return PCMCIA device attached to COMEDI device
  26  * @dev: COMEDI device.
  27  *
  28  * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
  29  * a &struct device embedded in a &struct pcmcia_device.
  30  *
  31  * Return: Attached PCMCIA device if @dev->hw_dev is non-%NULL.
  32  * Return %NULL if @dev->hw_dev is %NULL.
  33  */
  34 struct pcmcia_device *comedi_to_pcmcia_dev(struct comedi_device *dev)
  35 {
  36         return dev->hw_dev ? to_pcmcia_dev(dev->hw_dev) : NULL;
  37 }
  38 EXPORT_SYMBOL_GPL(comedi_to_pcmcia_dev);
  39
  40 static int comedi_pcmcia_conf_check(struct pcmcia_device *link,
  41                                     void *priv_data)
  42 {
  43         if (link->config_index == 0)
  44                 return -EINVAL;
  45
  46         return pcmcia_request_io(link);
  47 }
  48
  49 /**
  50  * comedi_pcmcia_enable() - Request the regions and enable the PCMCIA device
  51  * @dev: COMEDI device.
  52  * @conf_check: Optional callback to check each configuration option of the
  53  *      PCMCIA device and request I/O regions.
  54  *
  55  * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a a
  56  * &struct device embedded in a &struct pcmcia_device.  The comedi PCMCIA
  57  * driver needs to set the 'config_flags' member in the &struct pcmcia_device,
  58  * as appropriate for that driver, before calling this function in order to
  59  * allow pcmcia_loop_config() to do its internal autoconfiguration.
  60  *
  61  * If @conf_check is %NULL it is set to a default function.  If is
  62  * passed to pcmcia_loop_config() and should return %0 if the configuration
  63  * is valid and I/O regions requested successfully, otherwise it should return
  64  * a negative error value.  The default function returns -%EINVAL if the
  65  * 'config_index' member is %0, otherwise it calls pcmcia_request_io() and
  66  * returns the result.
  67  *
  68  * If the above configuration check passes, pcmcia_enable_device() is called
  69  * to set up and activate the PCMCIA device.
  70  *
  71  * If this function returns an error, comedi_pcmcia_disable() should be called
  72  * to release requested resources.
  73  *
  74  * Return:
  75  *      0 on success,
  76  *      -%ENODEV id @dev->hw_dev is %NULL,
  77  *      a negative error number from pcmcia_loop_config() if it fails,
  78  *      or a negative error number from pcmcia_enable_device() if it fails.
  79  */
  80 int comedi_pcmcia_enable(struct comedi_device *dev,
  81                          int (*conf_check)(struct pcmcia_device *, void *))
  82 {
  83         struct pcmcia_device *link = comedi_to_pcmcia_dev(dev);
  84         int ret;
  85
  86         if (!link)
  87                 return -ENODEV;
  88
  89         if (!conf_check)
  90                 conf_check = comedi_pcmcia_conf_check;
  91
  92         ret = pcmcia_loop_config(link, conf_check, NULL);
  93         if (ret)
  94                 return ret;
  95
  96         return pcmcia_enable_device(link);
  97 }
  98 EXPORT_SYMBOL_GPL(comedi_pcmcia_enable);
  99
 100 /**
 101  * comedi_pcmcia_disable() - Disable the PCMCIA device and release the regions
 102  * @dev: COMEDI device.
 103  *
 104  * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
 105  * a &struct device embedded in a &struct pcmcia_device.  Call
 106  * pcmcia_disable_device() to disable and clean up the PCMCIA device.
 107  */
 108 void comedi_pcmcia_disable(struct comedi_device *dev)
 109 {
 110         struct pcmcia_device *link = comedi_to_pcmcia_dev(dev);
 111
 112         if (link)
 113                 pcmcia_disable_device(link);
 114 }
 115 EXPORT_SYMBOL_GPL(comedi_pcmcia_disable);
 116
 117 /**
 118  * comedi_pcmcia_auto_config() - Configure/probe a PCMCIA COMEDI device
 119  * @link: PCMCIA device.
 120  * @driver: Registered COMEDI driver.
 121  *
 122  * Typically called from the pcmcia_driver (*probe) function.  Auto-configure
 123  * a COMEDI device, using a pointer to the &struct device embedded in *@link
 124  * as the hardware device.  The @driver's "auto_attach" handler may call
 125  * comedi_to_pcmcia_dev() on the passed in COMEDI device to recover @link.
 126  *
 127  * Return: The result of calling comedi_auto_config() (0 on success, or a
 128  * negative error number on failure).
 129  */
 130 int comedi_pcmcia_auto_config(struct pcmcia_device *link,
 131                               struct comedi_driver *driver)
 132 {
 133         return comedi_auto_config(&link->dev, driver, 0);
 134 }
 135 EXPORT_SYMBOL_GPL(comedi_pcmcia_auto_config);
 136
 137 /**
 138  * comedi_pcmcia_auto_unconfig() - Unconfigure/remove a PCMCIA COMEDI device
 139  * @link: PCMCIA device.
 140  *
 141  * Typically called from the pcmcia_driver (*remove) function.
 142  * Auto-unconfigure a COMEDI device attached to this PCMCIA device, using a
 143  * pointer to the &struct device embedded in *@link as the hardware device.
 144  * The COMEDI driver's "detach" handler will be called during unconfiguration
 145  * of the COMEDI device.
 146  *
 147  * Note that the COMEDI device may have already been unconfigured using the
 148  * %COMEDI_DEVCONFIG ioctl, in which case this attempt to unconfigure it
 149  * again should be ignored.
 150  */
 151 void comedi_pcmcia_auto_unconfig(struct pcmcia_device *link)
 152 {
 153         comedi_auto_unconfig(&link->dev);
 154 }
 155 EXPORT_SYMBOL_GPL(comedi_pcmcia_auto_unconfig);
 156
 157 /**
 158  * comedi_pcmcia_driver_register() - Register a PCMCIA COMEDI driver
 159  * @comedi_driver: COMEDI driver to be registered.
 160  * @pcmcia_driver: PCMCIA driver to be registered.
 161  *
 162  * This function is used for the module_init() of PCMCIA COMEDI driver modules
 163  * to register the COMEDI driver and the PCMCIA driver.  Do not call it
 164  * directly, use the module_comedi_pcmcia_driver() helper macro instead.
 165  *
 166  * Return: 0 on success, or a negative error number on failure.
 167  */
 168 int comedi_pcmcia_driver_register(struct comedi_driver *comedi_driver,
 169                                   struct pcmcia_driver *pcmcia_driver)
 170 {
 171         int ret;
 172
 173         ret = comedi_driver_register(comedi_driver);
 174         if (ret < 0)
 175                 return ret;
 176
 177         ret = pcmcia_register_driver(pcmcia_driver);
 178         if (ret < 0) {
 179                 comedi_driver_unregister(comedi_driver);
 180                 return ret;
 181         }
 182
 183         return 0;
 184 }
 185 EXPORT_SYMBOL_GPL(comedi_pcmcia_driver_register);
 186
 187 /**
 188  * comedi_pcmcia_driver_unregister() - Unregister a PCMCIA COMEDI driver
 189  * @comedi_driver: COMEDI driver to be registered.
 190  * @pcmcia_driver: PCMCIA driver to be registered.
 191  *
 192  * This function is called from the module_exit() of PCMCIA COMEDI driver
 193  * modules to unregister the PCMCIA driver and the COMEDI driver.  Do not call
 194  * it directly, use the module_comedi_pcmcia_driver() helper macro instead.
 195  */
 196 void comedi_pcmcia_driver_unregister(struct comedi_driver *comedi_driver,
 197                                      struct pcmcia_driver *pcmcia_driver)
 198 {
 199         pcmcia_unregister_driver(pcmcia_driver);
 200         comedi_driver_unregister(comedi_driver);
 201 }
 202 EXPORT_SYMBOL_GPL(comedi_pcmcia_driver_unregister);
 203
 204 static int __init comedi_pcmcia_init(void)
 205 {
 206         return 0;
 207 }
 208 module_init(comedi_pcmcia_init);
 209
 210 static void __exit comedi_pcmcia_exit(void)
 211 {
 212 }
 213 module_exit(comedi_pcmcia_exit);
 214
 215 MODULE_AUTHOR("http://www.comedi.org");
 216 MODULE_DESCRIPTION("Comedi PCMCIA interface module");
 217 MODULE_LICENSE("GPL");