[deliverable/linux.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_access = {
	.owner		= THIS_MODULE,
	.gpio_config	= scx200_gpio_configure,
	.gpio_dump	= nsc_gpio_dump,
	.gpio_get	= scx200_gpio_get,
	.gpio_set	= scx200_gpio_set,
	.gpio_set_high	= scx200_gpio_set_high,
	.gpio_set_low	= scx200_gpio_set_low,
	.gpio_change	= scx200_gpio_change,
	.gpio_current	= scx200_gpio_current
};
EXPORT_SYMBOL(scx200_access);

static int scx200_gpio_open(struct inode *inode, struct file *file)
{
	unsigned m = iminor(inode);
	file->private_data = &scx200_access;

	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_fops = {
	.owner   = THIS_MODULE,
	.write   = nsc_gpio_write,
	.read    = nsc_gpio_read,
	.open    = scx200_gpio_open,
	.release = scx200_gpio_release,
};

struct cdev *scx200_devices;

static int __init scx200_gpio_init(void)
{
	int rc, i;
	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_access.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;
	}
	scx200_devices = kzalloc(MAX_PINS * sizeof(struct cdev), GFP_KERNEL);
	if (!scx200_devices) {
		rc = -ENOMEM;
		goto undo_chrdev_region;
	}
	for (i = 0; i < MAX_PINS; i++) {
		struct cdev *cdev = &scx200_devices[i];
		cdev_init(cdev, &scx200_gpio_fops);
		cdev->owner = THIS_MODULE;
		rc = cdev_add(cdev, MKDEV(major, i), 1);
		/* tolerate 'minor' errors */
		if (rc)
			dev_err(&pdev->dev, "Error %d on minor %d", rc, i);
	}

	return 0; /* succeed */

undo_chrdev_region:
	unregister_chrdev_region(devid, MAX_PINS);
undo_platform_device_add:
	platform_device_del(pdev);
undo_malloc:
	platform_device_put(pdev);

	return rc;
}

static void __exit scx200_gpio_cleanup(void)
{
	kfree(scx200_devices);
	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
fe3a168a JC	38	struct nsc_gpio_ops scx200_access = {
	39	.owner = THIS_MODULE,
	40	.gpio_config = scx200_gpio_configure,
0e41ef3c	41	.gpio_dump = nsc_gpio_dump,
fe3a168a JC	42	.gpio_get = scx200_gpio_get,
	43	.gpio_set = scx200_gpio_set,
	44	.gpio_set_high = scx200_gpio_set_high,
	45	.gpio_set_low = scx200_gpio_set_low,
	46	.gpio_change = scx200_gpio_change,
	47	.gpio_current = scx200_gpio_current
	48	};
ae2d1f2f	49	EXPORT_SYMBOL(scx200_access);
fe3a168a	50
1da177e4 LT	51	static int scx200_gpio_open(struct inode inode, struct file file)
	52	{
	53	unsigned m = iminor(inode);
c3dc8071 JC	54	file->private_data = &scx200_access;
c3dc8071 JC	55
ae2d1f2f	56	if (m >= MAX_PINS)
1da177e4 LT	57	return -EINVAL;
	58	return nonseekable_open(inode, file);
	59	}
	60
	61	static int scx200_gpio_release(struct inode inode, struct file file)
	62	{
	63	return 0;
	64	}
	65
	66
62322d25	67	static const struct file_operations scx200_gpio_fops = {
1da177e4	68	.owner = THIS_MODULE,
1a66fdf0 JC	69	.write = nsc_gpio_write,
1a66fdf0 JC	70	.read = nsc_gpio_read,
1da177e4 LT	71	.open = scx200_gpio_open,
	72	.release = scx200_gpio_release,
	73	};
	74
7d7f2126	75	struct cdev *scx200_devices;
7d7f2126	76
1da177e4 LT	77	static int __init scx200_gpio_init(void)
1da177e4 LT	78	{
7d7f2126	79	int rc, i;
ae2d1f2f	80	dev_t devid;
1da177e4	81
1da177e4	82	if (!scx200_gpio_present()) {
ae2d1f2f	83	printk(KERN_ERR DRVNAME ": no SCx200 gpio present\n");
1da177e4 LT	84	return -ENODEV;
1da177e4 LT	85	}
979b5ec3 JC	86
979b5ec3 JC	87	/* support dev_dbg() with pdev->dev */
ae2d1f2f	88	pdev = platform_device_alloc(DRVNAME, 0);
979b5ec3 JC	89	if (!pdev)
	90	return -ENOMEM;
	91
	92	rc = platform_device_add(pdev);
	93	if (rc)
	94	goto undo_malloc;
	95
f31000e5 JC	96	/* nsc_gpio uses dev_dbg(), so needs this */
	97	scx200_access.dev = &pdev->dev;
	98
ae2d1f2f JC	99	if (major) {
	100	devid = MKDEV(major, 0);
	101	rc = register_chrdev_region(devid, MAX_PINS, "scx200_gpio");
	102	} else {
	103	rc = alloc_chrdev_region(&devid, 0, MAX_PINS, "scx200_gpio");
	104	major = MAJOR(devid);
1da177e4	105	}
7d7f2126	106	if (rc < 0) {
979b5ec3 JC	107	dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
979b5ec3 JC	108	goto undo_platform_device_add;
7d7f2126	109	}
ae2d1f2f	110	scx200_devices = kzalloc(MAX_PINS * sizeof(struct cdev), GFP_KERNEL);
7d7f2126 JC	111	if (!scx200_devices) {
7d7f2126 JC	112	rc = -ENOMEM;
979b5ec3	113	goto undo_chrdev_region;
7d7f2126	114	}
ae2d1f2f	115	for (i = 0; i < MAX_PINS; i++) {
7d7f2126 JC	116	struct cdev *cdev = &scx200_devices[i];
	117	cdev_init(cdev, &scx200_gpio_fops);
	118	cdev->owner = THIS_MODULE;
7d7f2126	119	rc = cdev_add(cdev, MKDEV(major, i), 1);
979b5ec3	120	/* tolerate 'minor' errors */
7d7f2126	121	if (rc)
979b5ec3	122	dev_err(&pdev->dev, "Error %d on minor %d", rc, i);
1da177e4 LT	123	}
1da177e4 LT	124
979b5ec3	125	return 0; /* succeed */
7d7f2126	126
979b5ec3	127	undo_chrdev_region:
ae2d1f2f	128	unregister_chrdev_region(devid, MAX_PINS);
979b5ec3	129	undo_platform_device_add:
1017f6af	130	platform_device_del(pdev);
979b5ec3	131	undo_malloc:
1017f6af IM	132	platform_device_put(pdev);
1017f6af IM	133
7d7f2126	134	return rc;
1da177e4 LT	135	}
	136
	137	static void __exit scx200_gpio_cleanup(void)
	138	{
7d7f2126	139	kfree(scx200_devices);
ae2d1f2f	140	unregister_chrdev_region(MKDEV(major, 0), MAX_PINS);
979b5ec3	141	platform_device_unregister(pdev);
1da177e4 LT	142	}
	143
	144	module_init(scx200_gpio_init);
	145	module_exit(scx200_gpio_cleanup);