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