1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * comedi_pci.c
4  * Comedi PCI 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/interrupt.h>
12 #include <linux/comedi/comedi_pci.h>
13 
14 /**
15  * comedi_to_pci_dev() - Return PCI 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 pci_dev.
20  *
21  * Return: Attached PCI device if @dev->hw_dev is non-%NULL.
22  * Return %NULL if @dev->hw_dev is %NULL.
23  */
comedi_to_pci_dev(struct comedi_device * dev)24 struct pci_dev *comedi_to_pci_dev(struct comedi_device *dev)
25 {
26 	return dev->hw_dev ? to_pci_dev(dev->hw_dev) : NULL;
27 }
28 EXPORT_SYMBOL_GPL(comedi_to_pci_dev);
29 
30 /**
31  * comedi_pci_enable() - Enable the PCI device and request the regions
32  * @dev: COMEDI device.
33  *
34  * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
35  * a &struct device embedded in a &struct pci_dev.  Enable the PCI device
36  * and request its regions.  Set @dev->ioenabled to %true if successful,
37  * otherwise undo what was done.
38  *
39  * Calls to comedi_pci_enable() and comedi_pci_disable() cannot be nested.
40  *
41  * Return:
42  *	0 on success,
43  *	-%ENODEV if @dev->hw_dev is %NULL,
44  *	-%EBUSY if regions busy,
45  *	or some negative error number if failed to enable PCI device.
46  *
47  */
comedi_pci_enable(struct comedi_device * dev)48 int comedi_pci_enable(struct comedi_device *dev)
49 {
50 	struct pci_dev *pcidev = comedi_to_pci_dev(dev);
51 	int rc;
52 
53 	if (!pcidev)
54 		return -ENODEV;
55 
56 	rc = pci_enable_device(pcidev);
57 	if (rc < 0)
58 		return rc;
59 
60 	rc = pci_request_regions(pcidev, dev->board_name);
61 	if (rc < 0)
62 		pci_disable_device(pcidev);
63 	else
64 		dev->ioenabled = true;
65 
66 	return rc;
67 }
68 EXPORT_SYMBOL_GPL(comedi_pci_enable);
69 
70 /**
71  * comedi_pci_disable() - Release the regions and disable the PCI device
72  * @dev: COMEDI device.
73  *
74  * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
75  * a &struct device embedded in a &struct pci_dev.  If the earlier call
76  * to comedi_pci_enable() was successful, release the PCI device's regions
77  * and disable it.  Reset @dev->ioenabled back to %false.
78  */
comedi_pci_disable(struct comedi_device * dev)79 void comedi_pci_disable(struct comedi_device *dev)
80 {
81 	struct pci_dev *pcidev = comedi_to_pci_dev(dev);
82 
83 	if (pcidev && dev->ioenabled) {
84 		pci_release_regions(pcidev);
85 		pci_disable_device(pcidev);
86 	}
87 	dev->ioenabled = false;
88 }
89 EXPORT_SYMBOL_GPL(comedi_pci_disable);
90 
91 /**
92  * comedi_pci_detach() - A generic "detach" handler for PCI COMEDI drivers
93  * @dev: COMEDI device.
94  *
95  * COMEDI drivers for PCI devices that need no special clean-up of private data
96  * and have no ioremapped regions other than that pointed to by @dev->mmio may
97  * use this function as its "detach" handler called by the COMEDI core when a
98  * COMEDI device is being detached from the low-level driver.  It may be also
99  * called from a more specific "detach" handler that does additional clean-up.
100  *
101  * Free the IRQ if @dev->irq is non-zero, iounmap @dev->mmio if it is
102  * non-%NULL, and call comedi_pci_disable() to release the PCI device's regions
103  * and disable it.
104  */
comedi_pci_detach(struct comedi_device * dev)105 void comedi_pci_detach(struct comedi_device *dev)
106 {
107 	struct pci_dev *pcidev = comedi_to_pci_dev(dev);
108 
109 	if (!pcidev || !dev->ioenabled)
110 		return;
111 
112 	if (dev->irq) {
113 		free_irq(dev->irq, dev);
114 		dev->irq = 0;
115 	}
116 	if (dev->mmio) {
117 		iounmap(dev->mmio);
118 		dev->mmio = NULL;
119 	}
120 	comedi_pci_disable(dev);
121 }
122 EXPORT_SYMBOL_GPL(comedi_pci_detach);
123 
124 /**
125  * comedi_pci_auto_config() - Configure/probe a PCI COMEDI device
126  * @pcidev: PCI device.
127  * @driver: Registered COMEDI driver.
128  * @context: Driver specific data, passed to comedi_auto_config().
129  *
130  * Typically called from the pci_driver (*probe) function.  Auto-configure
131  * a COMEDI device, using the &struct device embedded in *@pcidev as the
132  * hardware device.  The @context value gets passed through to @driver's
133  * "auto_attach" handler.  The "auto_attach" handler may call
134  * comedi_to_pci_dev() on the passed in COMEDI device to recover @pcidev.
135  *
136  * Return: The result of calling comedi_auto_config() (0 on success, or
137  * a negative error number on failure).
138  */
comedi_pci_auto_config(struct pci_dev * pcidev,struct comedi_driver * driver,unsigned long context)139 int comedi_pci_auto_config(struct pci_dev *pcidev,
140 			   struct comedi_driver *driver,
141 			   unsigned long context)
142 {
143 	return comedi_auto_config(&pcidev->dev, driver, context);
144 }
145 EXPORT_SYMBOL_GPL(comedi_pci_auto_config);
146 
147 /**
148  * comedi_pci_auto_unconfig() - Unconfigure/remove a PCI COMEDI device
149  * @pcidev: PCI device.
150  *
151  * Typically called from the pci_driver (*remove) function.  Auto-unconfigure
152  * a COMEDI device attached to this PCI device, using a pointer to the
153  * &struct device embedded in *@pcidev as the hardware device.  The COMEDI
154  * driver's "detach" handler will be called during unconfiguration of the
155  * COMEDI device.
156  *
157  * Note that the COMEDI device may have already been unconfigured using the
158  * %COMEDI_DEVCONFIG ioctl, in which case this attempt to unconfigure it
159  * again should be ignored.
160  */
comedi_pci_auto_unconfig(struct pci_dev * pcidev)161 void comedi_pci_auto_unconfig(struct pci_dev *pcidev)
162 {
163 	comedi_auto_unconfig(&pcidev->dev);
164 }
165 EXPORT_SYMBOL_GPL(comedi_pci_auto_unconfig);
166 
167 /**
168  * comedi_pci_driver_register() - Register a PCI COMEDI driver
169  * @comedi_driver: COMEDI driver to be registered.
170  * @pci_driver: PCI driver to be registered.
171  *
172  * This function is called from the module_init() of PCI COMEDI driver modules
173  * to register the COMEDI driver and the PCI driver.  Do not call it directly,
174  * use the module_comedi_pci_driver() helper macro instead.
175  *
176  * Return: 0 on success, or a negative error number on failure.
177  */
comedi_pci_driver_register(struct comedi_driver * comedi_driver,struct pci_driver * pci_driver)178 int comedi_pci_driver_register(struct comedi_driver *comedi_driver,
179 			       struct pci_driver *pci_driver)
180 {
181 	int ret;
182 
183 	ret = comedi_driver_register(comedi_driver);
184 	if (ret < 0)
185 		return ret;
186 
187 	ret = pci_register_driver(pci_driver);
188 	if (ret < 0) {
189 		comedi_driver_unregister(comedi_driver);
190 		return ret;
191 	}
192 
193 	return 0;
194 }
195 EXPORT_SYMBOL_GPL(comedi_pci_driver_register);
196 
197 /**
198  * comedi_pci_driver_unregister() - Unregister a PCI COMEDI driver
199  * @comedi_driver: COMEDI driver to be unregistered.
200  * @pci_driver: PCI driver to be unregistered.
201  *
202  * This function is called from the module_exit() of PCI COMEDI driver modules
203  * to unregister the PCI driver and the COMEDI driver.  Do not call it
204  * directly, use the module_comedi_pci_driver() helper macro instead.
205  */
comedi_pci_driver_unregister(struct comedi_driver * comedi_driver,struct pci_driver * pci_driver)206 void comedi_pci_driver_unregister(struct comedi_driver *comedi_driver,
207 				  struct pci_driver *pci_driver)
208 {
209 	pci_unregister_driver(pci_driver);
210 	comedi_driver_unregister(comedi_driver);
211 }
212 EXPORT_SYMBOL_GPL(comedi_pci_driver_unregister);
213 
comedi_pci_init(void)214 static int __init comedi_pci_init(void)
215 {
216 	return 0;
217 }
218 module_init(comedi_pci_init);
219 
comedi_pci_exit(void)220 static void __exit comedi_pci_exit(void)
221 {
222 }
223 module_exit(comedi_pci_exit);
224 
225 MODULE_AUTHOR("https://www.comedi.org");
226 MODULE_DESCRIPTION("Comedi PCI interface module");
227 MODULE_LICENSE("GPL");
228