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

// SPDX-License-Identifier: GPL-2.0-only
/* 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 <linux/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,
	.llseek  = no_llseek,
};

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
09c434b8	1	// SPDX-License-Identifier: GPL-2.0-only
62c83cde	2	/* linux/drivers/char/scx200_gpio.c
1da177e4 LT	3
	4	National Semiconductor SCx200 GPIO driver. Allows a user space
	5	process to play with the GPIO pins.
	6
	7	Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */
	8
979b5ec3	9	#include <linux/device.h>
1da177e4 LT	10	#include <linux/fs.h>
	11	#include <linux/module.h>
	12	#include <linux/errno.h>
	13	#include <linux/kernel.h>
	14	#include <linux/init.h>
979b5ec3	15	#include <linux/platform_device.h>
7c0f6ba6	16	#include <linux/uaccess.h>
1da177e4 LT	17	#include <asm/io.h>
1da177e4 LT	18
7d7f2126 JC	19	#include <linux/types.h>
	20	#include <linux/cdev.h>
	21
1da177e4	22	#include <linux/scx200_gpio.h>
fe3a168a	23	#include <linux/nsc_gpio.h>
1da177e4	24
ae2d1f2f	25	#define DRVNAME "scx200_gpio"
979b5ec3 JC	26
979b5ec3 JC	27	static struct platform_device *pdev;
1da177e4 LT	28
1da177e4 LT	29	MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
ae2d1f2f	30	MODULE_DESCRIPTION("NatSemi/AMD SCx200 GPIO Pin Driver");
1da177e4 LT	31	MODULE_LICENSE("GPL");
	32
	33	static int major = 0; /* default to dynamic major */
	34	module_param(major, int, 0);
	35	MODULE_PARM_DESC(major, "Major device number");
	36
ae2d1f2f JC	37	#define MAX_PINS 32 /* 64 later, when known ok */
ae2d1f2f JC	38
2e8f7a31	39	struct nsc_gpio_ops scx200_gpio_ops = {
fe3a168a JC	40	.owner = THIS_MODULE,
fe3a168a JC	41	.gpio_config = scx200_gpio_configure,
0e41ef3c	42	.gpio_dump = nsc_gpio_dump,
fe3a168a JC	43	.gpio_get = scx200_gpio_get,
fe3a168a JC	44	.gpio_set = scx200_gpio_set,
fe3a168a JC	45	.gpio_change = scx200_gpio_change,
	46	.gpio_current = scx200_gpio_current
	47	};
58012cd7	48	EXPORT_SYMBOL_GPL(scx200_gpio_ops);
fe3a168a	49
1da177e4 LT	50	static int scx200_gpio_open(struct inode inode, struct file file)
	51	{
	52	unsigned m = iminor(inode);
2e8f7a31	53	file->private_data = &scx200_gpio_ops;
c3dc8071	54
ae2d1f2f	55	if (m >= MAX_PINS)
1da177e4 LT	56	return -EINVAL;
	57	return nonseekable_open(inode, file);
	58	}
	59
	60	static int scx200_gpio_release(struct inode inode, struct file file)
	61	{
	62	return 0;
	63	}
	64
2e8f7a31	65	static const struct file_operations scx200_gpio_fileops = {
1da177e4	66	.owner = THIS_MODULE,
1a66fdf0 JC	67	.write = nsc_gpio_write,
1a66fdf0 JC	68	.read = nsc_gpio_read,
1da177e4 LT	69	.open = scx200_gpio_open,
1da177e4 LT	70	.release = scx200_gpio_release,
6038f373	71	.llseek = no_llseek,
1da177e4 LT	72	};
1da177e4 LT	73
c8ad9681	74	static struct cdev scx200_gpio_cdev; /* use 1 cdev for all pins */
7d7f2126	75
1da177e4 LT	76	static int __init scx200_gpio_init(void)
1da177e4 LT	77	{
635adb6c	78	int rc;
ae2d1f2f	79	dev_t devid;
1da177e4	80
1da177e4	81	if (!scx200_gpio_present()) {
ae2d1f2f	82	printk(KERN_ERR DRVNAME ": no SCx200 gpio present\n");
1da177e4 LT	83	return -ENODEV;
1da177e4 LT	84	}
979b5ec3 JC	85
979b5ec3 JC	86	/* support dev_dbg() with pdev->dev */
ae2d1f2f	87	pdev = platform_device_alloc(DRVNAME, 0);
979b5ec3 JC	88	if (!pdev)
	89	return -ENOMEM;
	90
	91	rc = platform_device_add(pdev);
	92	if (rc)
	93	goto undo_malloc;
	94
f31000e5	95	/* nsc_gpio uses dev_dbg(), so needs this */
2e8f7a31	96	scx200_gpio_ops.dev = &pdev->dev;
f31000e5	97
ae2d1f2f JC	98	if (major) {
	99	devid = MKDEV(major, 0);
	100	rc = register_chrdev_region(devid, MAX_PINS, "scx200_gpio");
	101	} else {
	102	rc = alloc_chrdev_region(&devid, 0, MAX_PINS, "scx200_gpio");
	103	major = MAJOR(devid);
1da177e4	104	}
7d7f2126	105	if (rc < 0) {
979b5ec3 JC	106	dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
979b5ec3 JC	107	goto undo_platform_device_add;
7d7f2126	108	}
635adb6c	109
2e8f7a31	110	cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
635adb6c	111	cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
1da177e4	112
979b5ec3	113	return 0; /* succeed */
7d7f2126	114
979b5ec3	115	undo_platform_device_add:
1017f6af	116	platform_device_del(pdev);
979b5ec3	117	undo_malloc:
1017f6af IM	118	platform_device_put(pdev);
1017f6af IM	119
7d7f2126	120	return rc;
1da177e4 LT	121	}
	122
	123	static void __exit scx200_gpio_cleanup(void)
	124	{
635adb6c JC	125	cdev_del(&scx200_gpio_cdev);
	126	/* cdev_put(&scx200_gpio_cdev); */
	127
ae2d1f2f	128	unregister_chrdev_region(MKDEV(major, 0), MAX_PINS);
979b5ec3	129	platform_device_unregister(pdev);
1da177e4 LT	130	}
	131
	132	module_init(scx200_gpio_init);
	133	module_exit(scx200_gpio_cleanup);