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");
210