[linux-2.6-block.git] / drivers / char / scx200_gpio.c

/* linux/drivers/char/scx200_gpio.c

   National Semiconductor SCx200 GPIO driver.  Allows a user space
   process to play with the GPIO pins.

   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */

#include <linux/device.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#include <linux/types.h>
#include <linux/cdev.h>

#include <linux/scx200_gpio.h>
#include <linux/nsc_gpio.h>

#define DRVNAME "scx200_gpio"

static struct platform_device *pdev;

MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
MODULE_DESCRIPTION("NatSemi/AMD SCx200 GPIO Pin Driver");
MODULE_LICENSE("GPL");

static int major = 0;		/* default to dynamic major */
module_param(major, int, 0);
MODULE_PARM_DESC(major, "Major device number");

#define MAX_PINS 32		/* 64 later, when known ok */

struct nsc_gpio_ops scx200_gpio_ops = {
	.owner		= THIS_MODULE,
	.gpio_config	= scx200_gpio_configure,
	.gpio_dump	= nsc_gpio_dump,
	.gpio_get	= scx200_gpio_get,
	.gpio_set	= scx200_gpio_set,
	.gpio_change	= scx200_gpio_change,
	.gpio_current	= scx200_gpio_current
};
EXPORT_SYMBOL_GPL(scx200_gpio_ops);

static int scx200_gpio_open(struct inode *inode, struct file *file)
{
	unsigned m = iminor(inode);
	file->private_data = &scx200_gpio_ops;

	if (m >= MAX_PINS)
		return -EINVAL;
	return nonseekable_open(inode, file);
}

static int scx200_gpio_release(struct inode *inode, struct file *file)
{
	return 0;
}

static const struct file_operations scx200_gpio_fileops = {
	.owner   = THIS_MODULE,
	.write   = nsc_gpio_write,
	.read    = nsc_gpio_read,
	.open    = scx200_gpio_open,
	.release = scx200_gpio_release,
};

static struct cdev scx200_gpio_cdev;  /* use 1 cdev for all pins */

static int __init scx200_gpio_init(void)
{
	int rc;
	dev_t devid;

	if (!scx200_gpio_present()) {
		printk(KERN_ERR DRVNAME ": no SCx200 gpio present\n");
		return -ENODEV;
	}

	/* support dev_dbg() with pdev->dev */
	pdev = platform_device_alloc(DRVNAME, 0);
	if (!pdev)
		return -ENOMEM;

	rc = platform_device_add(pdev);
	if (rc)
		goto undo_malloc;

	/* nsc_gpio uses dev_dbg(), so needs this */
	scx200_gpio_ops.dev = &pdev->dev;

	if (major) {
		devid = MKDEV(major, 0);
		rc = register_chrdev_region(devid, MAX_PINS, "scx200_gpio");
	} else {
		rc = alloc_chrdev_region(&devid, 0, MAX_PINS, "scx200_gpio");
		major = MAJOR(devid);
	}
	if (rc < 0) {
		dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
		goto undo_platform_device_add;
	}

	cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
	cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);

	return 0; /* succeed */

undo_platform_device_add:
	platform_device_del(pdev);
undo_malloc:
	platform_device_put(pdev);

	return rc;
}

static void __exit scx200_gpio_cleanup(void)
{
	cdev_del(&scx200_gpio_cdev);
	/* cdev_put(&scx200_gpio_cdev); */

	unregister_chrdev_region(MKDEV(major, 0), MAX_PINS);
	platform_device_unregister(pdev);
}

module_init(scx200_gpio_init);
module_exit(scx200_gpio_cleanup);
Commit	Line	Data
62c83cde	1	/* linux/drivers/char/scx200_gpio.c
1da177e4 LT	2
	3	National Semiconductor SCx200 GPIO driver. Allows a user space
	4	process to play with the GPIO pins.
	5
	6	Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */
	7
979b5ec3	8	#include <linux/device.h>
1da177e4 LT	9	#include <linux/fs.h>
	10	#include <linux/module.h>
	11	#include <linux/errno.h>
	12	#include <linux/kernel.h>
	13	#include <linux/init.h>
979b5ec3	14	#include <linux/platform_device.h>
1da177e4 LT	15	#include <asm/uaccess.h>
	16	#include <asm/io.h>
	17
7d7f2126 JC	18	#include <linux/types.h>
	19	#include <linux/cdev.h>
	20
1da177e4	21	#include <linux/scx200_gpio.h>
fe3a168a	22	#include <linux/nsc_gpio.h>
1da177e4	23
ae2d1f2f	24	#define DRVNAME "scx200_gpio"
979b5ec3 JC	25
979b5ec3 JC	26	static struct platform_device *pdev;
1da177e4 LT	27
1da177e4 LT	28	MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
ae2d1f2f	29	MODULE_DESCRIPTION("NatSemi/AMD SCx200 GPIO Pin Driver");
1da177e4 LT	30	MODULE_LICENSE("GPL");
	31
	32	static int major = 0; /* default to dynamic major */
	33	module_param(major, int, 0);
	34	MODULE_PARM_DESC(major, "Major device number");
	35
ae2d1f2f JC	36	#define MAX_PINS 32 /* 64 later, when known ok */
ae2d1f2f JC	37
2e8f7a31	38	struct nsc_gpio_ops scx200_gpio_ops = {
fe3a168a JC	39	.owner = THIS_MODULE,
fe3a168a JC	40	.gpio_config = scx200_gpio_configure,
0e41ef3c	41	.gpio_dump = nsc_gpio_dump,
fe3a168a JC	42	.gpio_get = scx200_gpio_get,
fe3a168a JC	43	.gpio_set = scx200_gpio_set,
fe3a168a JC	44	.gpio_change = scx200_gpio_change,
	45	.gpio_current = scx200_gpio_current
	46	};
58012cd7	47	EXPORT_SYMBOL_GPL(scx200_gpio_ops);
fe3a168a	48
1da177e4 LT	49	static int scx200_gpio_open(struct inode inode, struct file file)
	50	{
	51	unsigned m = iminor(inode);
2e8f7a31	52	file->private_data = &scx200_gpio_ops;
c3dc8071	53
ae2d1f2f	54	if (m >= MAX_PINS)
1da177e4 LT	55	return -EINVAL;
	56	return nonseekable_open(inode, file);
	57	}
	58
	59	static int scx200_gpio_release(struct inode inode, struct file file)
	60	{
	61	return 0;
	62	}
	63
2e8f7a31	64	static const struct file_operations scx200_gpio_fileops = {
1da177e4	65	.owner = THIS_MODULE,
1a66fdf0 JC	66	.write = nsc_gpio_write,
1a66fdf0 JC	67	.read = nsc_gpio_read,
1da177e4 LT	68	.open = scx200_gpio_open,
	69	.release = scx200_gpio_release,
	70	};
	71
c8ad9681	72	static struct cdev scx200_gpio_cdev; /* use 1 cdev for all pins */
7d7f2126	73
1da177e4 LT	74	static int __init scx200_gpio_init(void)
1da177e4 LT	75	{
635adb6c	76	int rc;
ae2d1f2f	77	dev_t devid;
1da177e4	78
1da177e4	79	if (!scx200_gpio_present()) {
ae2d1f2f	80	printk(KERN_ERR DRVNAME ": no SCx200 gpio present\n");
1da177e4 LT	81	return -ENODEV;
1da177e4 LT	82	}
979b5ec3 JC	83
979b5ec3 JC	84	/* support dev_dbg() with pdev->dev */
ae2d1f2f	85	pdev = platform_device_alloc(DRVNAME, 0);
979b5ec3 JC	86	if (!pdev)
	87	return -ENOMEM;
	88
	89	rc = platform_device_add(pdev);
	90	if (rc)
	91	goto undo_malloc;
	92
f31000e5	93	/* nsc_gpio uses dev_dbg(), so needs this */
2e8f7a31	94	scx200_gpio_ops.dev = &pdev->dev;
f31000e5	95
ae2d1f2f JC	96	if (major) {
	97	devid = MKDEV(major, 0);
	98	rc = register_chrdev_region(devid, MAX_PINS, "scx200_gpio");
	99	} else {
	100	rc = alloc_chrdev_region(&devid, 0, MAX_PINS, "scx200_gpio");
	101	major = MAJOR(devid);
1da177e4	102	}
7d7f2126	103	if (rc < 0) {
979b5ec3 JC	104	dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
979b5ec3 JC	105	goto undo_platform_device_add;
7d7f2126	106	}
635adb6c	107
2e8f7a31	108	cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
635adb6c	109	cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
1da177e4	110
979b5ec3	111	return 0; /* succeed */
7d7f2126	112
979b5ec3	113	undo_platform_device_add:
1017f6af	114	platform_device_del(pdev);
979b5ec3	115	undo_malloc:
1017f6af IM	116	platform_device_put(pdev);
1017f6af IM	117
7d7f2126	118	return rc;
1da177e4 LT	119	}
	120
	121	static void __exit scx200_gpio_cleanup(void)
	122	{
635adb6c JC	123	cdev_del(&scx200_gpio_cdev);
	124	/* cdev_put(&scx200_gpio_cdev); */
	125
ae2d1f2f	126	unregister_chrdev_region(MKDEV(major, 0), MAX_PINS);
979b5ec3	127	platform_device_unregister(pdev);
1da177e4 LT	128	}
	129
	130	module_init(scx200_gpio_init);
	131	module_exit(scx200_gpio_cleanup);