xref: /linux/drivers/uio/uio_aec.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  * uio_aec.c -- simple driver for Adrienne Electronics Corp time code PCI device
3  *
4  * Copyright (C) 2008 Brandon Philips <brandon@ifup.org>
5  *
6  *   This program is free software; you can redistribute it and/or modify it
7  *   under the terms of the GNU General Public License version 2 as published
8  *   by the Free Software Foundation.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *   GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License along
16  *   with this program; if not, write to the Free Software Foundation, Inc., 59
17  *   Temple Place, Suite 330, Boston, MA 02111-1307, USA.
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/pci.h>
23 #include <linux/init.h>
24 #include <linux/interrupt.h>
25 #include <linux/cdev.h>
26 #include <linux/fs.h>
27 #include <linux/io.h>
28 #include <linux/uaccess.h>
29 #include <linux/uio_driver.h>
30 
31 #define PCI_VENDOR_ID_AEC 0xaecb
32 #define PCI_DEVICE_ID_AEC_VITCLTC 0x6250
33 
34 #define INT_ENABLE_ADDR		0xFC
35 #define INT_ENABLE		0x10
36 #define INT_DISABLE		0x0
37 
38 #define INT_MASK_ADDR		0x2E
39 #define INT_MASK_ALL		0x3F
40 
41 #define INTA_DRVR_ADDR		0xFE
42 #define INTA_ENABLED_FLAG	0x08
43 #define INTA_FLAG		0x01
44 
45 #define MAILBOX			0x0F
46 
47 static struct pci_device_id ids[] = {
48 	{ PCI_DEVICE(PCI_VENDOR_ID_AEC, PCI_DEVICE_ID_AEC_VITCLTC), },
49 	{ 0, }
50 };
51 MODULE_DEVICE_TABLE(pci, ids);
52 
53 static irqreturn_t aectc_irq(int irq, struct uio_info *dev_info)
54 {
55 	void __iomem *int_flag = dev_info->priv + INTA_DRVR_ADDR;
56 	unsigned char status = ioread8(int_flag);
57 
58 
59 	if ((status & INTA_ENABLED_FLAG) && (status & INTA_FLAG)) {
60 		/* application writes 0x00 to 0x2F to get next interrupt */
61 		status = ioread8(dev_info->priv + MAILBOX);
62 		return IRQ_HANDLED;
63 	}
64 
65 	return IRQ_NONE;
66 }
67 
68 static void print_board_data(struct pci_dev *pdev, struct uio_info *i)
69 {
70 	dev_info(&pdev->dev, "PCI-TC board vendor: %x%x number: %x%x"
71 		" revision: %c%c\n",
72 		ioread8(i->priv + 0x01),
73 		ioread8(i->priv + 0x00),
74 		ioread8(i->priv + 0x03),
75 		ioread8(i->priv + 0x02),
76 		ioread8(i->priv + 0x06),
77 		ioread8(i->priv + 0x07));
78 }
79 
80 static int __devinit probe(struct pci_dev *pdev, const struct pci_device_id *id)
81 {
82 	struct uio_info *info;
83 	int ret;
84 
85 	info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
86 	if (!info)
87 		return -ENOMEM;
88 
89 	if (pci_enable_device(pdev))
90 		goto out_free;
91 
92 	if (pci_request_regions(pdev, "aectc"))
93 		goto out_disable;
94 
95 	info->name = "aectc";
96 	info->port[0].start = pci_resource_start(pdev, 0);
97 	if (!info->port[0].start)
98 		goto out_release;
99 	info->priv = pci_iomap(pdev, 0, 0);
100 	if (!info->priv)
101 		goto out_release;
102 	info->port[0].size = pci_resource_len(pdev, 0);
103 	info->port[0].porttype = UIO_PORT_GPIO;
104 
105 	info->version = "0.0.1";
106 	info->irq = pdev->irq;
107 	info->irq_flags = IRQF_SHARED;
108 	info->handler = aectc_irq;
109 
110 	print_board_data(pdev, info);
111 	ret = uio_register_device(&pdev->dev, info);
112 	if (ret)
113 		goto out_unmap;
114 
115 	iowrite32(INT_ENABLE, info->priv + INT_ENABLE_ADDR);
116 	iowrite8(INT_MASK_ALL, info->priv + INT_MASK_ADDR);
117 	if (!(ioread8(info->priv + INTA_DRVR_ADDR)
118 			& INTA_ENABLED_FLAG))
119 		dev_err(&pdev->dev, "aectc: interrupts not enabled\n");
120 
121 	pci_set_drvdata(pdev, info);
122 
123 	return 0;
124 
125 out_unmap:
126 	pci_iounmap(pdev, info->priv);
127 out_release:
128 	pci_release_regions(pdev);
129 out_disable:
130 	pci_disable_device(pdev);
131 out_free:
132 	kfree(info);
133 	return -ENODEV;
134 }
135 
136 static void remove(struct pci_dev *pdev)
137 {
138 	struct uio_info *info = pci_get_drvdata(pdev);
139 
140 	/* disable interrupts */
141 	iowrite8(INT_DISABLE, info->priv + INT_MASK_ADDR);
142 	iowrite32(INT_DISABLE, info->priv + INT_ENABLE_ADDR);
143 	/* read mailbox to ensure board drops irq */
144 	ioread8(info->priv + MAILBOX);
145 
146 	uio_unregister_device(info);
147 	pci_release_regions(pdev);
148 	pci_disable_device(pdev);
149 	pci_set_drvdata(pdev, NULL);
150 	iounmap(info->priv);
151 
152 	kfree(info);
153 }
154 
155 static struct pci_driver pci_driver = {
156 	.name = "aectc",
157 	.id_table = ids,
158 	.probe = probe,
159 	.remove = remove,
160 };
161 
162 static int __init aectc_init(void)
163 {
164 	return pci_register_driver(&pci_driver);
165 }
166 
167 static void __exit aectc_exit(void)
168 {
169 	pci_unregister_driver(&pci_driver);
170 }
171 
172 MODULE_LICENSE("GPL");
173 
174 module_init(aectc_init);
175 module_exit(aectc_exit);
176