1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * uio_aec.c -- simple driver for Adrienne Electronics Corp time code PCI device
4 *
5 * Copyright (C) 2008 Brandon Philips <brandon@ifup.org>
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/pci.h>
11#include <linux/init.h>
12#include <linux/interrupt.h>
13#include <linux/cdev.h>
14#include <linux/fs.h>
15#include <linux/io.h>
16#include <linux/uaccess.h>
17#include <linux/uio_driver.h>
18#include <linux/slab.h>
19
20#define PCI_VENDOR_ID_AEC 0xaecb
21#define PCI_DEVICE_ID_AEC_VITCLTC 0x6250
22
23#define INT_ENABLE_ADDR		0xFC
24#define INT_ENABLE		0x10
25#define INT_DISABLE		0x0
26
27#define INT_MASK_ADDR		0x2E
28#define INT_MASK_ALL		0x3F
29
30#define INTA_DRVR_ADDR		0xFE
31#define INTA_ENABLED_FLAG	0x08
32#define INTA_FLAG		0x01
33
34#define MAILBOX			0x0F
35
36static struct pci_device_id ids[] = {
37	{ PCI_DEVICE(PCI_VENDOR_ID_AEC, PCI_DEVICE_ID_AEC_VITCLTC), },
38	{ 0, }
39};
40MODULE_DEVICE_TABLE(pci, ids);
41
42static irqreturn_t aectc_irq(int irq, struct uio_info *dev_info)
43{
44	void __iomem *int_flag = dev_info->priv + INTA_DRVR_ADDR;
45	unsigned char status = ioread8(int_flag);
46
47
48	if ((status & INTA_ENABLED_FLAG) && (status & INTA_FLAG)) {
49		/* application writes 0x00 to 0x2F to get next interrupt */
50		status = ioread8(dev_info->priv + MAILBOX);
51		return IRQ_HANDLED;
52	}
53
54	return IRQ_NONE;
55}
56
57static void print_board_data(struct pci_dev *pdev, struct uio_info *i)
58{
59	dev_info(&pdev->dev, "PCI-TC board vendor: %x%x number: %x%x"
60		" revision: %c%c\n",
61		ioread8(i->priv + 0x01),
62		ioread8(i->priv + 0x00),
63		ioread8(i->priv + 0x03),
64		ioread8(i->priv + 0x02),
65		ioread8(i->priv + 0x06),
66		ioread8(i->priv + 0x07));
67}
68
69static int probe(struct pci_dev *pdev, const struct pci_device_id *id)
70{
71	struct uio_info *info;
72	int ret;
73
74	info = devm_kzalloc(&pdev->dev, sizeof(struct uio_info), GFP_KERNEL);
75	if (!info)
76		return -ENOMEM;
77
78	if (pci_enable_device(pdev))
79		return -ENODEV;
80
81	if (pci_request_regions(pdev, "aectc"))
82		goto out_disable;
83
84	info->name = "aectc";
85	info->port[0].start = pci_resource_start(pdev, 0);
86	if (!info->port[0].start)
87		goto out_release;
88	info->priv = pci_iomap(pdev, 0, 0);
89	if (!info->priv)
90		goto out_release;
91	info->port[0].size = pci_resource_len(pdev, 0);
92	info->port[0].porttype = UIO_PORT_GPIO;
93
94	info->version = "0.0.1";
95	info->irq = pdev->irq;
96	info->irq_flags = IRQF_SHARED;
97	info->handler = aectc_irq;
98
99	print_board_data(pdev, info);
100	ret = uio_register_device(&pdev->dev, info);
101	if (ret)
102		goto out_unmap;
103
104	iowrite32(INT_ENABLE, info->priv + INT_ENABLE_ADDR);
105	iowrite8(INT_MASK_ALL, info->priv + INT_MASK_ADDR);
106	if (!(ioread8(info->priv + INTA_DRVR_ADDR)
107			& INTA_ENABLED_FLAG))
108		dev_err(&pdev->dev, "aectc: interrupts not enabled\n");
109
110	pci_set_drvdata(pdev, info);
111
112	return 0;
113
114out_unmap:
115	pci_iounmap(pdev, info->priv);
116out_release:
117	pci_release_regions(pdev);
118out_disable:
119	pci_disable_device(pdev);
120	return -ENODEV;
121}
122
123static void remove(struct pci_dev *pdev)
124{
125	struct uio_info *info = pci_get_drvdata(pdev);
126
127	/* disable interrupts */
128	iowrite8(INT_DISABLE, info->priv + INT_MASK_ADDR);
129	iowrite32(INT_DISABLE, info->priv + INT_ENABLE_ADDR);
130	/* read mailbox to ensure board drops irq */
131	ioread8(info->priv + MAILBOX);
132
133	uio_unregister_device(info);
134	pci_release_regions(pdev);
135	pci_disable_device(pdev);
136	pci_iounmap(pdev, info->priv);
137}
138
139static struct pci_driver pci_driver = {
140	.name = "aectc",
141	.id_table = ids,
142	.probe = probe,
143	.remove = remove,
144};
145
146module_pci_driver(pci_driver);
147MODULE_LICENSE("GPL");
148