gio.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * arch/sh/boards/landisk/gio.c - driver for landisk
  4 *
  5 * This driver will also support the I-O DATA Device, Inc. LANDISK Board.
  6 * LANDISK and USL-5P Button, LED and GIO driver drive function.
  7 *
  8 *   Copylight (C) 2006 kogiidena
  9 *   Copylight (C) 2002 Atom Create Engineering Co., Ltd. *
 10 */
 11#include <linux/module.h>
 12#include <linux/init.h>
 13#include <linux/kdev_t.h>
 14#include <linux/cdev.h>
 15#include <linux/fs.h>
 16#include <asm/io.h>
 17#include <linux/uaccess.h>
 18#include <mach-landisk/mach/gio.h>
 19#include <mach-landisk/mach/iodata_landisk.h>
 20
 21#define DEVCOUNT                4
 22#define GIO_MINOR	        2	/* GIO minor no. */
 23
 24static dev_t dev;
 25static struct cdev *cdev_p;
 26static int openCnt;
 27
 28static int gio_open(struct inode *inode, struct file *filp)
 29{
 30	int minor = iminor(inode);
 31	int ret = -ENOENT;
 32
 33	preempt_disable();
 34	if (minor < DEVCOUNT) {
 35		if (openCnt > 0) {
 36			ret = -EALREADY;
 37		} else {
 38			openCnt++;
 39			ret = 0;
 40		}
 41	}
 42	preempt_enable();
 43	return ret;
 44}
 45
 46static int gio_close(struct inode *inode, struct file *filp)
 47{
 48	int minor = iminor(inode);
 49
 50	if (minor < DEVCOUNT) {
 51		openCnt--;
 52	}
 53	return 0;
 54}
 55
 56static long gio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 57{
 58	unsigned int data;
 59	static unsigned int addr = 0;
 60
 61	if (cmd & 0x01) {	/* write */
 62		if (copy_from_user(&data, (int *)arg, sizeof(int))) {
 63			return -EFAULT;
 64		}
 65	}
 66
 67	switch (cmd) {
 68	case GIODRV_IOCSGIOSETADDR:	/* address set */
 69		addr = data;
 70		break;
 71
 72	case GIODRV_IOCSGIODATA1:	/* write byte */
 73		__raw_writeb((unsigned char)(0x0ff & data), addr);
 74		break;
 75
 76	case GIODRV_IOCSGIODATA2:	/* write word */
 77		if (addr & 0x01) {
 78			return -EFAULT;
 79		}
 80		__raw_writew((unsigned short int)(0x0ffff & data), addr);
 81		break;
 82
 83	case GIODRV_IOCSGIODATA4:	/* write long */
 84		if (addr & 0x03) {
 85			return -EFAULT;
 86		}
 87		__raw_writel(data, addr);
 88		break;
 89
 90	case GIODRV_IOCGGIODATA1:	/* read byte */
 91		data = __raw_readb(addr);
 92		break;
 93
 94	case GIODRV_IOCGGIODATA2:	/* read word */
 95		if (addr & 0x01) {
 96			return -EFAULT;
 97		}
 98		data = __raw_readw(addr);
 99		break;
100
101	case GIODRV_IOCGGIODATA4:	/* read long */
102		if (addr & 0x03) {
103			return -EFAULT;
104		}
105		data = __raw_readl(addr);
106		break;
107	default:
108		return -EFAULT;
109		break;
110	}
111
112	if ((cmd & 0x01) == 0) {	/* read */
113		if (copy_to_user((int *)arg, &data, sizeof(int))) {
114			return -EFAULT;
115		}
116	}
117	return 0;
118}
119
120static const struct file_operations gio_fops = {
121	.owner = THIS_MODULE,
122	.open = gio_open,	/* open */
123	.release = gio_close,	/* release */
124	.unlocked_ioctl = gio_ioctl,
125	.llseek = noop_llseek,
126};
127
128static int __init gio_init(void)
129{
130	int error;
131
132	printk(KERN_INFO "gio: driver initialized\n");
133
134	openCnt = 0;
135
136	if ((error = alloc_chrdev_region(&dev, 0, DEVCOUNT, "gio")) < 0) {
137		printk(KERN_ERR
138		       "gio: Couldn't alloc_chrdev_region, error=%d\n",
139		       error);
140		return 1;
141	}
142
143	cdev_p = cdev_alloc();
144	cdev_p->ops = &gio_fops;
145	error = cdev_add(cdev_p, dev, DEVCOUNT);
146	if (error) {
147		printk(KERN_ERR
148		       "gio: Couldn't cdev_add, error=%d\n", error);
149		return 1;
150	}
151
152	return 0;
153}
154
155static void __exit gio_exit(void)
156{
157	cdev_del(cdev_p);
158	unregister_chrdev_region(dev, DEVCOUNT);
159}
160
161module_init(gio_init);
162module_exit(gio_exit);
163
164MODULE_LICENSE("GPL");