drivers/staging/comedi/comedi_pcmcia.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * comedi_pcmcia.c
   4  * Comedi PCMCIA driver specific functions.
   5  *
   6  * COMEDI - Linux Control and Measurement Device Interface
   7  * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12
  13 #include "comedi_pcmcia.h"
  14
  15 /**
  16  * comedi_to_pcmcia_dev() - Return PCMCIA device attached to COMEDI device
  17  * @dev: COMEDI device.
  18  *
  19  * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
  20  * a &struct device embedded in a &struct pcmcia_device.
  21  *
  22  * Return: Attached PCMCIA device if @dev->hw_dev is non-%NULL.
  23  * Return %NULL if @dev->hw_dev is %NULL.
  24  */
  25 struct pcmcia_device *comedi_to_pcmcia_dev(struct comedi_device *dev)
  26 {
  27         return dev->hw_dev ? to_pcmcia_dev(dev->hw_dev) : NULL;
  28 }
  29 EXPORT_SYMBOL_GPL(comedi_to_pcmcia_dev);
  30
  31 static int comedi_pcmcia_conf_check(struct pcmcia_device *link,
  32                                     void *priv_data)
  33 {
  34         if (link->config_index == 0)
  35                 return -EINVAL;
  36
  37         return pcmcia_request_io(link);
  38 }
  39
  40 /**
  41  * comedi_pcmcia_enable() - Request the regions and enable the PCMCIA device
  42  * @dev: COMEDI device.
  43  * @conf_check: Optional callback to check each configuration option of the
  44  *      PCMCIA device and request I/O regions.
  45  *
  46  * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a a
  47  * &struct device embedded in a &struct pcmcia_device.  The comedi PCMCIA
  48  * driver needs to set the 'config_flags' member in the &struct pcmcia_device,
  49  * as appropriate for that driver, before calling this function in order to
  50  * allow pcmcia_loop_config() to do its internal autoconfiguration.
  51  *
  52  * If @conf_check is %NULL it is set to a default function.  If is
  53  * passed to pcmcia_loop_config() and should return %0 if the configuration
  54  * is valid and I/O regions requested successfully, otherwise it should return
  55  * a negative error value.  The default function returns -%EINVAL if the
  56  * 'config_index' member is %0, otherwise it calls pcmcia_request_io() and
  57  * returns the result.
  58  *
  59  * If the above configuration check passes, pcmcia_enable_device() is called
  60  * to set up and activate the PCMCIA device.
  61  *
  62  * If this function returns an error, comedi_pcmcia_disable() should be called
  63  * to release requested resources.
  64  *
  65  * Return:
  66  *      0 on success,
  67  *      -%ENODEV id @dev->hw_dev is %NULL,
  68  *      a negative error number from pcmcia_loop_config() if it fails,
  69  *      or a negative error number from pcmcia_enable_device() if it fails.
  70  */
  71 int comedi_pcmcia_enable(struct comedi_device *dev,
  72                          int (*conf_check)(struct pcmcia_device *p_dev,
  73                                            void *priv_data))
  74 {
  75         struct pcmcia_device *link = comedi_to_pcmcia_dev(dev);
  76         int ret;
  77
  78         if (!link)
  79                 return -ENODEV;
  80
  81         if (!conf_check)
  82                 conf_check = comedi_pcmcia_conf_check;
  83
  84         ret = pcmcia_loop_config(link, conf_check, NULL);
  85         if (ret)
  86                 return ret;
  87
  88         return pcmcia_enable_device(link);
  89 }
  90 EXPORT_SYMBOL_GPL(comedi_pcmcia_enable);
  91
  92 /**
  93  * comedi_pcmcia_disable() - Disable the PCMCIA device and release the regions
  94  * @dev: COMEDI device.
  95  *
  96  * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
  97  * a &struct device embedded in a &struct pcmcia_device.  Call
  98  * pcmcia_disable_device() to disable and clean up the PCMCIA device.
  99  */
 100 void comedi_pcmcia_disable(struct comedi_device *dev)
 101 {
 102         struct pcmcia_device *link = comedi_to_pcmcia_dev(dev);
 103
 104         if (link)
 105                 pcmcia_disable_device(link);
 106 }
 107 EXPORT_SYMBOL_GPL(comedi_pcmcia_disable);
 108
 109 /**
 110  * comedi_pcmcia_auto_config() - Configure/probe a PCMCIA COMEDI device
 111  * @link: PCMCIA device.
 112  * @driver: Registered COMEDI driver.
 113  *
 114  * Typically called from the pcmcia_driver (*probe) function.  Auto-configure
 115  * a COMEDI device, using a pointer to the &struct device embedded in *@link
 116  * as the hardware device.  The @driver's "auto_attach" handler may call
 117  * comedi_to_pcmcia_dev() on the passed in COMEDI device to recover @link.
 118  *
 119  * Return: The result of calling comedi_auto_config() (0 on success, or a
 120  * negative error number on failure).
 121  */
 122 int comedi_pcmcia_auto_config(struct pcmcia_device *link,
 123                               struct comedi_driver *driver)
 124 {
 125         return comedi_auto_config(&link->dev, driver, 0);
 126 }
 127 EXPORT_SYMBOL_GPL(comedi_pcmcia_auto_config);
 128
 129 /**
 130  * comedi_pcmcia_auto_unconfig() - Unconfigure/remove a PCMCIA COMEDI device
 131  * @link: PCMCIA device.
 132  *
 133  * Typically called from the pcmcia_driver (*remove) function.
 134  * Auto-unconfigure a COMEDI device attached to this PCMCIA device, using a
 135  * pointer to the &struct device embedded in *@link as the hardware device.
 136  * The COMEDI driver's "detach" handler will be called during unconfiguration
 137  * of the COMEDI device.
 138  *
 139  * Note that the COMEDI device may have already been unconfigured using the
 140  * %COMEDI_DEVCONFIG ioctl, in which case this attempt to unconfigure it
 141  * again should be ignored.
 142  */
 143 void comedi_pcmcia_auto_unconfig(struct pcmcia_device *link)
 144 {
 145         comedi_auto_unconfig(&link->dev);
 146 }
 147 EXPORT_SYMBOL_GPL(comedi_pcmcia_auto_unconfig);
 148
 149 /**
 150  * comedi_pcmcia_driver_register() - Register a PCMCIA COMEDI driver
 151  * @comedi_driver: COMEDI driver to be registered.
 152  * @pcmcia_driver: PCMCIA driver to be registered.
 153  *
 154  * This function is used for the module_init() of PCMCIA COMEDI driver modules
 155  * to register the COMEDI driver and the PCMCIA driver.  Do not call it
 156  * directly, use the module_comedi_pcmcia_driver() helper macro instead.
 157  *
 158  * Return: 0 on success, or a negative error number on failure.
 159  */
 160 int comedi_pcmcia_driver_register(struct comedi_driver *comedi_driver,
 161                                   struct pcmcia_driver *pcmcia_driver)
 162 {
 163         int ret;
 164
 165         ret = comedi_driver_register(comedi_driver);
 166         if (ret < 0)
 167                 return ret;
 168
 169         ret = pcmcia_register_driver(pcmcia_driver);
 170         if (ret < 0) {
 171                 comedi_driver_unregister(comedi_driver);
 172                 return ret;
 173         }
 174
 175         return 0;
 176 }
 177 EXPORT_SYMBOL_GPL(comedi_pcmcia_driver_register);
 178
 179 /**
 180  * comedi_pcmcia_driver_unregister() - Unregister a PCMCIA COMEDI driver
 181  * @comedi_driver: COMEDI driver to be registered.
 182  * @pcmcia_driver: PCMCIA driver to be registered.
 183  *
 184  * This function is called from the module_exit() of PCMCIA COMEDI driver
 185  * modules to unregister the PCMCIA driver and the COMEDI driver.  Do not call
 186  * it directly, use the module_comedi_pcmcia_driver() helper macro instead.
 187  */
 188 void comedi_pcmcia_driver_unregister(struct comedi_driver *comedi_driver,
 189                                      struct pcmcia_driver *pcmcia_driver)
 190 {
 191         pcmcia_unregister_driver(pcmcia_driver);
 192         comedi_driver_unregister(comedi_driver);
 193 }
 194 EXPORT_SYMBOL_GPL(comedi_pcmcia_driver_unregister);
 195
 196 static int __init comedi_pcmcia_init(void)
 197 {
 198         return 0;
 199 }
 200 module_init(comedi_pcmcia_init);
 201
 202 static void __exit comedi_pcmcia_exit(void)
 203 {
 204 }
 205 module_exit(comedi_pcmcia_exit);
 206
 207 MODULE_AUTHOR("https://www.comedi.org");
 208 MODULE_DESCRIPTION("Comedi PCMCIA interface module");
 209 MODULE_LICENSE("GPL");