[mirror_ubuntu-bionic-kernel.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/config.h>
#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 NAME "scx200_gpio"
#define DEVNAME NAME

static struct platform_device *pdev;

MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
MODULE_DESCRIPTION("NatSemi 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");

extern void scx200_gpio_dump(unsigned index);

struct nsc_gpio_ops scx200_access = {
	.owner		= THIS_MODULE,
	.gpio_config	= scx200_gpio_configure,
	.gpio_dump	= scx200_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
};

static ssize_t scx200_gpio_write(struct file *file, const char __user *data,
				 size_t len, loff_t *ppos)
{
	unsigned m = iminor(file->f_dentry->d_inode);
	size_t i;
	int err = 0;

	for (i = 0; i < len; ++i) {
		char c;
		if (get_user(c, data + i))
			return -EFAULT;
		switch (c) {
		case '0':
			scx200_gpio_set(m, 0);
			break;
		case '1':
			scx200_gpio_set(m, 1);
			break;
		case 'O':
			printk(KERN_INFO NAME ": GPIO%d output enabled\n", m);
			scx200_gpio_configure(m, ~1, 1);
			break;
		case 'o':
			printk(KERN_INFO NAME ": GPIO%d output disabled\n", m);
			scx200_gpio_configure(m, ~1, 0);
			break;
		case 'T':
			printk(KERN_INFO NAME ": GPIO%d output is push pull\n", m);
			scx200_gpio_configure(m, ~2, 2);
			break;
		case 't':
			printk(KERN_INFO NAME ": GPIO%d output is open drain\n", m);
			scx200_gpio_configure(m, ~2, 0);
			break;
		case 'P':
			printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m);
			scx200_gpio_configure(m, ~4, 4);
			break;
		case 'p':
			printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m);
			scx200_gpio_configure(m, ~4, 0);
			break;

		case 'v':
			/* View Current pin settings */
			scx200_gpio_dump(m);
			break;
		case '\n':
			/* end of settings string, do nothing */
			break;
		default:
			printk(KERN_ERR NAME
			       ": GPIO-%2d bad setting: chr<0x%2x>\n", m,
			       (int)c);
			err++;
		}
	}
	if (err)
		return -EINVAL;	/* full string handled, report error */

	return len;
}

static ssize_t scx200_gpio_read(struct file *file, char __user *buf,
				size_t len, loff_t *ppos)
{
	unsigned m = iminor(file->f_dentry->d_inode);
	int value;

	value = scx200_gpio_get(m);
	if (put_user(value ? '1' : '0', buf))
		return -EFAULT;

	return 1;
}

static int scx200_gpio_open(struct inode *inode, struct file *file)
{
	unsigned m = iminor(inode);
	if (m > 63)
		return -EINVAL;
	return nonseekable_open(inode, file);
}

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


static struct file_operations scx200_gpio_fops = {
	.owner   = THIS_MODULE,
	.write   = scx200_gpio_write,
	.read    = scx200_gpio_read,
	.open    = scx200_gpio_open,
	.release = scx200_gpio_release,
};

struct cdev *scx200_devices;
static int num_pins = 32;

static int __init scx200_gpio_init(void)
{
	int rc, i;
	dev_t dev = MKDEV(major, 0);

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

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

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

	if (major)
		rc = register_chrdev_region(dev, num_pins, "scx200_gpio");
	else {
		rc = alloc_chrdev_region(&dev, 0, num_pins, "scx200_gpio");
		major = MAJOR(dev);
	}
	if (rc < 0) {
		dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
		goto undo_platform_device_add;
	}
	scx200_devices = kzalloc(num_pins * sizeof(struct cdev), GFP_KERNEL);
	if (!scx200_devices) {
		rc = -ENOMEM;
		goto undo_chrdev_region;
	}
	for (i = 0; i < num_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(dev, num_pins);
undo_platform_device_add:
	platform_device_put(pdev);
undo_malloc:
	kfree(pdev);
	return rc;
}

static void __exit scx200_gpio_cleanup(void)
{
	kfree(scx200_devices);
	unregister_chrdev_region(MKDEV(major, 0), num_pins);
	platform_device_put(pdev);
	platform_device_unregister(pdev);
	/* kfree(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
	8	#include <linux/config.h>
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>
1da177e4 LT	16	#include <asm/uaccess.h>
	17	#include <asm/io.h>
	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 LT	24
1da177e4 LT	25	#define NAME "scx200_gpio"
979b5ec3 JC	26	#define DEVNAME NAME
	27
	28	static struct platform_device *pdev;
1da177e4 LT	29
	30	MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
	31	MODULE_DESCRIPTION("NatSemi SCx200 GPIO Pin Driver");
	32	MODULE_LICENSE("GPL");
	33
	34	static int major = 0; /* default to dynamic major */
	35	module_param(major, int, 0);
	36	MODULE_PARM_DESC(major, "Major device number");
	37
7d7f2126 JC	38	extern void scx200_gpio_dump(unsigned index);
7d7f2126 JC	39
fe3a168a JC	40	struct nsc_gpio_ops scx200_access = {
	41	.owner = THIS_MODULE,
	42	.gpio_config = scx200_gpio_configure,
	43	.gpio_dump = scx200_gpio_dump,
	44	.gpio_get = scx200_gpio_get,
	45	.gpio_set = scx200_gpio_set,
	46	.gpio_set_high = scx200_gpio_set_high,
	47	.gpio_set_low = scx200_gpio_set_low,
	48	.gpio_change = scx200_gpio_change,
	49	.gpio_current = scx200_gpio_current
	50	};
	51
62c83cde	52	static ssize_t scx200_gpio_write(struct file file, const char __user data,
1da177e4 LT	53	size_t len, loff_t *ppos)
	54	{
	55	unsigned m = iminor(file->f_dentry->d_inode);
	56	size_t i;
9550a339	57	int err = 0;
1da177e4 LT	58
	59	for (i = 0; i < len; ++i) {
	60	char c;
62c83cde	61	if (get_user(c, data + i))
1da177e4	62	return -EFAULT;
62c83cde JC	63	switch (c) {
	64	case '0':
	65	scx200_gpio_set(m, 0);
1da177e4	66	break;
62c83cde JC	67	case '1':
62c83cde JC	68	scx200_gpio_set(m, 1);
1da177e4 LT	69	break;
	70	case 'O':
	71	printk(KERN_INFO NAME ": GPIO%d output enabled\n", m);
	72	scx200_gpio_configure(m, ~1, 1);
	73	break;
	74	case 'o':
	75	printk(KERN_INFO NAME ": GPIO%d output disabled\n", m);
	76	scx200_gpio_configure(m, ~1, 0);
	77	break;
	78	case 'T':
	79	printk(KERN_INFO NAME ": GPIO%d output is push pull\n", m);
	80	scx200_gpio_configure(m, ~2, 2);
	81	break;
	82	case 't':
	83	printk(KERN_INFO NAME ": GPIO%d output is open drain\n", m);
	84	scx200_gpio_configure(m, ~2, 0);
	85	break;
	86	case 'P':
	87	printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m);
	88	scx200_gpio_configure(m, ~4, 4);
	89	break;
	90	case 'p':
	91	printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m);
	92	scx200_gpio_configure(m, ~4, 0);
	93	break;
9550a339 JC	94
	95	case 'v':
	96	/* View Current pin settings */
	97	scx200_gpio_dump(m);
	98	break;
	99	case '\n':
	100	/* end of settings string, do nothing */
	101	break;
	102	default:
	103	printk(KERN_ERR NAME
	104	": GPIO-%2d bad setting: chr<0x%2x>\n", m,
	105	(int)c);
	106	err++;
1da177e4 LT	107	}
1da177e4 LT	108	}
9550a339 JC	109	if (err)
9550a339 JC	110	return -EINVAL; /* full string handled, report error */
1da177e4 LT	111
	112	return len;
	113	}
	114
	115	static ssize_t scx200_gpio_read(struct file file, char __user buf,
	116	size_t len, loff_t *ppos)
	117	{
	118	unsigned m = iminor(file->f_dentry->d_inode);
	119	int value;
	120
	121	value = scx200_gpio_get(m);
	122	if (put_user(value ? '1' : '0', buf))
	123	return -EFAULT;
62c83cde	124
1da177e4 LT	125	return 1;
	126	}
	127
	128	static int scx200_gpio_open(struct inode inode, struct file file)
	129	{
	130	unsigned m = iminor(inode);
	131	if (m > 63)
	132	return -EINVAL;
	133	return nonseekable_open(inode, file);
	134	}
	135
	136	static int scx200_gpio_release(struct inode inode, struct file file)
	137	{
	138	return 0;
	139	}
	140
	141
	142	static struct file_operations scx200_gpio_fops = {
	143	.owner = THIS_MODULE,
	144	.write = scx200_gpio_write,
	145	.read = scx200_gpio_read,
	146	.open = scx200_gpio_open,
	147	.release = scx200_gpio_release,
	148	};
	149
7d7f2126	150	struct cdev *scx200_devices;
979b5ec3	151	static int num_pins = 32;
7d7f2126	152
1da177e4 LT	153	static int __init scx200_gpio_init(void)
1da177e4 LT	154	{
7d7f2126 JC	155	int rc, i;
7d7f2126 JC	156	dev_t dev = MKDEV(major, 0);
1da177e4	157
1da177e4	158	if (!scx200_gpio_present()) {
7d7f2126	159	printk(KERN_ERR NAME ": no SCx200 gpio present\n");
1da177e4 LT	160	return -ENODEV;
1da177e4 LT	161	}
979b5ec3 JC	162
	163	/* support dev_dbg() with pdev->dev */
	164	pdev = platform_device_alloc(DEVNAME, 0);
	165	if (!pdev)
	166	return -ENOMEM;
	167
	168	rc = platform_device_add(pdev);
	169	if (rc)
	170	goto undo_malloc;
	171
7d7f2126	172	if (major)
979b5ec3	173	rc = register_chrdev_region(dev, num_pins, "scx200_gpio");
7d7f2126	174	else {
979b5ec3	175	rc = alloc_chrdev_region(&dev, 0, num_pins, "scx200_gpio");
7d7f2126	176	major = MAJOR(dev);
1da177e4	177	}
7d7f2126	178	if (rc < 0) {
979b5ec3 JC	179	dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
979b5ec3 JC	180	goto undo_platform_device_add;
7d7f2126	181	}
979b5ec3	182	scx200_devices = kzalloc(num_pins * sizeof(struct cdev), GFP_KERNEL);
7d7f2126 JC	183	if (!scx200_devices) {
7d7f2126 JC	184	rc = -ENOMEM;
979b5ec3	185	goto undo_chrdev_region;
7d7f2126	186	}
979b5ec3	187	for (i = 0; i < num_pins; i++) {
7d7f2126 JC	188	struct cdev *cdev = &scx200_devices[i];
	189	cdev_init(cdev, &scx200_gpio_fops);
	190	cdev->owner = THIS_MODULE;
7d7f2126	191	rc = cdev_add(cdev, MKDEV(major, i), 1);
979b5ec3	192	/* tolerate 'minor' errors */
7d7f2126	193	if (rc)
979b5ec3	194	dev_err(&pdev->dev, "Error %d on minor %d", rc, i);
1da177e4 LT	195	}
1da177e4 LT	196
979b5ec3	197	return 0; /* succeed */
7d7f2126	198
979b5ec3 JC	199	undo_chrdev_region:
	200	unregister_chrdev_region(dev, num_pins);
	201	undo_platform_device_add:
	202	platform_device_put(pdev);
	203	undo_malloc:
	204	kfree(pdev);
7d7f2126	205	return rc;
1da177e4 LT	206	}
	207
	208	static void __exit scx200_gpio_cleanup(void)
	209	{
7d7f2126	210	kfree(scx200_devices);
979b5ec3 JC	211	unregister_chrdev_region(MKDEV(major, 0), num_pins);
	212	platform_device_put(pdev);
	213	platform_device_unregister(pdev);
	214	/* kfree(pdev); */
1da177e4 LT	215	}
	216
	217	module_init(scx200_gpio_init);
	218	module_exit(scx200_gpio_cleanup);