[GitHub/mt8127/android_kernel_alcatel_ttab.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>

#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);

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 LT	22	#include <linux/scx200_gpio.h>
	23
	24	#define NAME "scx200_gpio"
979b5ec3 JC	25	#define DEVNAME NAME
	26
	27	static struct platform_device *pdev;
1da177e4 LT	28
	29	MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
	30	MODULE_DESCRIPTION("NatSemi SCx200 GPIO Pin Driver");
	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
7d7f2126 JC	37	extern void scx200_gpio_dump(unsigned index);
7d7f2126 JC	38
62c83cde	39	static ssize_t scx200_gpio_write(struct file file, const char __user data,
1da177e4 LT	40	size_t len, loff_t *ppos)
	41	{
	42	unsigned m = iminor(file->f_dentry->d_inode);
	43	size_t i;
9550a339	44	int err = 0;
1da177e4 LT	45
	46	for (i = 0; i < len; ++i) {
	47	char c;
62c83cde	48	if (get_user(c, data + i))
1da177e4	49	return -EFAULT;
62c83cde JC	50	switch (c) {
	51	case '0':
	52	scx200_gpio_set(m, 0);
1da177e4	53	break;
62c83cde JC	54	case '1':
62c83cde JC	55	scx200_gpio_set(m, 1);
1da177e4 LT	56	break;
	57	case 'O':
	58	printk(KERN_INFO NAME ": GPIO%d output enabled\n", m);
	59	scx200_gpio_configure(m, ~1, 1);
	60	break;
	61	case 'o':
	62	printk(KERN_INFO NAME ": GPIO%d output disabled\n", m);
	63	scx200_gpio_configure(m, ~1, 0);
	64	break;
	65	case 'T':
	66	printk(KERN_INFO NAME ": GPIO%d output is push pull\n", m);
	67	scx200_gpio_configure(m, ~2, 2);
	68	break;
	69	case 't':
	70	printk(KERN_INFO NAME ": GPIO%d output is open drain\n", m);
	71	scx200_gpio_configure(m, ~2, 0);
	72	break;
	73	case 'P':
	74	printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m);
	75	scx200_gpio_configure(m, ~4, 4);
	76	break;
	77	case 'p':
	78	printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m);
	79	scx200_gpio_configure(m, ~4, 0);
	80	break;
9550a339 JC	81
	82	case 'v':
	83	/* View Current pin settings */
	84	scx200_gpio_dump(m);
	85	break;
	86	case '\n':
	87	/* end of settings string, do nothing */
	88	break;
	89	default:
	90	printk(KERN_ERR NAME
	91	": GPIO-%2d bad setting: chr<0x%2x>\n", m,
	92	(int)c);
	93	err++;
1da177e4 LT	94	}
1da177e4 LT	95	}
9550a339 JC	96	if (err)
9550a339 JC	97	return -EINVAL; /* full string handled, report error */
1da177e4 LT	98
	99	return len;
	100	}
	101
	102	static ssize_t scx200_gpio_read(struct file file, char __user buf,
	103	size_t len, loff_t *ppos)
	104	{
	105	unsigned m = iminor(file->f_dentry->d_inode);
	106	int value;
	107
	108	value = scx200_gpio_get(m);
	109	if (put_user(value ? '1' : '0', buf))
	110	return -EFAULT;
62c83cde	111
1da177e4 LT	112	return 1;
	113	}
	114
	115	static int scx200_gpio_open(struct inode inode, struct file file)
	116	{
	117	unsigned m = iminor(inode);
	118	if (m > 63)
	119	return -EINVAL;
	120	return nonseekable_open(inode, file);
	121	}
	122
	123	static int scx200_gpio_release(struct inode inode, struct file file)
	124	{
	125	return 0;
	126	}
	127
	128
	129	static struct file_operations scx200_gpio_fops = {
	130	.owner = THIS_MODULE,
	131	.write = scx200_gpio_write,
	132	.read = scx200_gpio_read,
	133	.open = scx200_gpio_open,
	134	.release = scx200_gpio_release,
	135	};
	136
7d7f2126	137	struct cdev *scx200_devices;
979b5ec3	138	static int num_pins = 32;
7d7f2126	139
1da177e4 LT	140	static int __init scx200_gpio_init(void)
1da177e4 LT	141	{
7d7f2126 JC	142	int rc, i;
7d7f2126 JC	143	dev_t dev = MKDEV(major, 0);
1da177e4	144
1da177e4	145	if (!scx200_gpio_present()) {
7d7f2126	146	printk(KERN_ERR NAME ": no SCx200 gpio present\n");
1da177e4 LT	147	return -ENODEV;
1da177e4 LT	148	}
979b5ec3 JC	149
	150	/* support dev_dbg() with pdev->dev */
	151	pdev = platform_device_alloc(DEVNAME, 0);
	152	if (!pdev)
	153	return -ENOMEM;
	154
	155	rc = platform_device_add(pdev);
	156	if (rc)
	157	goto undo_malloc;
	158
7d7f2126	159	if (major)
979b5ec3	160	rc = register_chrdev_region(dev, num_pins, "scx200_gpio");
7d7f2126	161	else {
979b5ec3	162	rc = alloc_chrdev_region(&dev, 0, num_pins, "scx200_gpio");
7d7f2126	163	major = MAJOR(dev);
1da177e4	164	}
7d7f2126	165	if (rc < 0) {
979b5ec3 JC	166	dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
979b5ec3 JC	167	goto undo_platform_device_add;
7d7f2126	168	}
979b5ec3	169	scx200_devices = kzalloc(num_pins * sizeof(struct cdev), GFP_KERNEL);
7d7f2126 JC	170	if (!scx200_devices) {
7d7f2126 JC	171	rc = -ENOMEM;
979b5ec3	172	goto undo_chrdev_region;
7d7f2126	173	}
979b5ec3	174	for (i = 0; i < num_pins; i++) {
7d7f2126 JC	175	struct cdev *cdev = &scx200_devices[i];
	176	cdev_init(cdev, &scx200_gpio_fops);
	177	cdev->owner = THIS_MODULE;
7d7f2126	178	rc = cdev_add(cdev, MKDEV(major, i), 1);
979b5ec3	179	/* tolerate 'minor' errors */
7d7f2126	180	if (rc)
979b5ec3	181	dev_err(&pdev->dev, "Error %d on minor %d", rc, i);
1da177e4 LT	182	}
1da177e4 LT	183
979b5ec3	184	return 0; /* succeed */
7d7f2126	185
979b5ec3 JC	186	undo_chrdev_region:
	187	unregister_chrdev_region(dev, num_pins);
	188	undo_platform_device_add:
	189	platform_device_put(pdev);
	190	undo_malloc:
	191	kfree(pdev);
7d7f2126	192	return rc;
1da177e4 LT	193	}
	194
	195	static void __exit scx200_gpio_cleanup(void)
	196	{
7d7f2126	197	kfree(scx200_devices);
979b5ec3 JC	198	unregister_chrdev_region(MKDEV(major, 0), num_pins);
	199	platform_device_put(pdev);
	200	platform_device_unregister(pdev);
	201	/* kfree(pdev); */
1da177e4 LT	202	}
	203
	204	module_init(scx200_gpio_init);
	205	module_exit(scx200_gpio_cleanup);