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

// SPDX-License-Identifier: GPL-2.0-only
/* linux/drivers/char/nsc_gpio.c

   National Semiconductor common GPIO device-file/VFS methods.
   Allows a user space process to control the GPIO pins.

   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
   Copyright (c) 2005      Jim Cromie <jim.cromie@gmail.com>
*/

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

#define NAME "nsc_gpio"

void nsc_gpio_dump(struct nsc_gpio_ops *amp, unsigned index)
{
	/* retrieve current config w/o changing it */
	u32 config = amp->gpio_config(index, ~0, 0);

	/* user requested via 'v' command, so its INFO */
	dev_info(amp->dev, "io%02u: 0x%04x %s %s %s %s %s %s %s\tio:%d/%d\n",
		 index, config,
		 (config & 1) ? "OE" : "TS",      /* output-enabled/tristate */
		 (config & 2) ? "PP" : "OD",      /* push pull / open drain */
		 (config & 4) ? "PUE" : "PUD",    /* pull up enabled/disabled */
		 (config & 8) ? "LOCKED" : "",    /* locked / unlocked */
		 (config & 16) ? "LEVEL" : "EDGE",/* level/edge input */
		 (config & 32) ? "HI" : "LO",     /* trigger on rise/fall edge */
		 (config & 64) ? "DEBOUNCE" : "", /* debounce */

		 amp->gpio_get(index), amp->gpio_current(index));
}

ssize_t nsc_gpio_write(struct file *file, const char __user *data,
		       size_t len, loff_t *ppos)
{
	unsigned m = iminor(file_inode(file));
	struct nsc_gpio_ops *amp = file->private_data;
	struct device *dev = amp->dev;
	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':
			amp->gpio_set(m, 0);
			break;
		case '1':
			amp->gpio_set(m, 1);
			break;
		case 'O':
			dev_dbg(dev, "GPIO%d output enabled\n", m);
			amp->gpio_config(m, ~1, 1);
			break;
		case 'o':
			dev_dbg(dev, "GPIO%d output disabled\n", m);
			amp->gpio_config(m, ~1, 0);
			break;
		case 'T':
			dev_dbg(dev, "GPIO%d output is push pull\n", m);
			amp->gpio_config(m, ~2, 2);
			break;
		case 't':
			dev_dbg(dev, "GPIO%d output is open drain\n", m);
			amp->gpio_config(m, ~2, 0);
			break;
		case 'P':
			dev_dbg(dev, "GPIO%d pull up enabled\n", m);
			amp->gpio_config(m, ~4, 4);
			break;
		case 'p':
			dev_dbg(dev, "GPIO%d pull up disabled\n", m);
			amp->gpio_config(m, ~4, 0);
			break;
		case 'v':
			/* View Current pin settings */
			amp->gpio_dump(amp, m);
			break;
		case '\n':
			/* end of settings string, do nothing */
			break;
		default:
			dev_err(dev, "io%2d bad setting: chr<0x%2x>\n",
				m, (int)c);
			err++;
		}
	}
	if (err)
		return -EINVAL;	/* full string handled, report error */

	return len;
}

ssize_t nsc_gpio_read(struct file *file, char __user * buf,
		      size_t len, loff_t * ppos)
{
	unsigned m = iminor(file_inode(file));
	int value;
	struct nsc_gpio_ops *amp = file->private_data;

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

	return 1;
}

/* common file-ops routines for both scx200_gpio and pc87360_gpio */
EXPORT_SYMBOL(nsc_gpio_write);
EXPORT_SYMBOL(nsc_gpio_read);
EXPORT_SYMBOL(nsc_gpio_dump);

static int __init nsc_gpio_init(void)
{
	printk(KERN_DEBUG NAME " initializing\n");
	return 0;
}

static void __exit nsc_gpio_cleanup(void)
{
	printk(KERN_DEBUG NAME " cleanup\n");
}

module_init(nsc_gpio_init);
module_exit(nsc_gpio_cleanup);

MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");
MODULE_DESCRIPTION("NatSemi GPIO Common Methods");
MODULE_LICENSE("GPL");
Commit	Line	Data
09c434b8	1	// SPDX-License-Identifier: GPL-2.0-only
1ca5df0a JC	2	/* linux/drivers/char/nsc_gpio.c
	3
	4	National Semiconductor common GPIO device-file/VFS methods.
	5	Allows a user space process to control the GPIO pins.
	6
	7	Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
	8	Copyright (c) 2005 Jim Cromie <jim.cromie@gmail.com>
	9	*/
	10
1ca5df0a JC	11	#include <linux/fs.h>
	12	#include <linux/module.h>
	13	#include <linux/errno.h>
	14	#include <linux/kernel.h>
	15	#include <linux/init.h>
	16	#include <linux/nsc_gpio.h>
f31000e5	17	#include <linux/platform_device.h>
7c0f6ba6	18	#include <linux/uaccess.h>
1ca5df0a JC	19	#include <asm/io.h>
	20
	21	#define NAME "nsc_gpio"
	22
f31000e5	23	void nsc_gpio_dump(struct nsc_gpio_ops *amp, unsigned index)
0e41ef3c	24	{
f31000e5 JC	25	/* retrieve current config w/o changing it */
	26	u32 config = amp->gpio_config(index, ~0, 0);
	27
	28	/* user requested via 'v' command, so its INFO */
23916a8e	29	dev_info(amp->dev, "io%02u: 0x%04x %s %s %s %s %s %s %s\tio:%d/%d\n",
f31000e5 JC	30	index, config,
	31	(config & 1) ? "OE" : "TS", /* output-enabled/tristate */
	32	(config & 2) ? "PP" : "OD", /* push pull / open drain */
	33	(config & 4) ? "PUE" : "PUD", /* pull up enabled/disabled */
	34	(config & 8) ? "LOCKED" : "", /* locked / unlocked */
	35	(config & 16) ? "LEVEL" : "EDGE",/* level/edge input */
	36	(config & 32) ? "HI" : "LO", /* trigger on rise/fall edge */
23916a8e JC	37	(config & 64) ? "DEBOUNCE" : "", /* debounce */
	38
	39	amp->gpio_get(index), amp->gpio_current(index));
0e41ef3c JC	40	}
0e41ef3c JC	41
1a66fdf0 JC	42	ssize_t nsc_gpio_write(struct file file, const char __user data,
	43	size_t len, loff_t *ppos)
	44	{
496ad9aa	45	unsigned m = iminor(file_inode(file));
1a66fdf0	46	struct nsc_gpio_ops *amp = file->private_data;
f31000e5	47	struct device *dev = amp->dev;
1a66fdf0 JC	48	size_t i;
	49	int err = 0;
	50
	51	for (i = 0; i < len; ++i) {
	52	char c;
	53	if (get_user(c, data + i))
	54	return -EFAULT;
	55	switch (c) {
	56	case '0':
	57	amp->gpio_set(m, 0);
	58	break;
	59	case '1':
	60	amp->gpio_set(m, 1);
	61	break;
	62	case 'O':
f31000e5	63	dev_dbg(dev, "GPIO%d output enabled\n", m);
1a66fdf0 JC	64	amp->gpio_config(m, ~1, 1);
	65	break;
	66	case 'o':
f31000e5	67	dev_dbg(dev, "GPIO%d output disabled\n", m);
1a66fdf0 JC	68	amp->gpio_config(m, ~1, 0);
	69	break;
	70	case 'T':
abecb6da	71	dev_dbg(dev, "GPIO%d output is push pull\n", m);
1a66fdf0 JC	72	amp->gpio_config(m, ~2, 2);
	73	break;
	74	case 't':
abecb6da	75	dev_dbg(dev, "GPIO%d output is open drain\n", m);
1a66fdf0 JC	76	amp->gpio_config(m, ~2, 0);
	77	break;
	78	case 'P':
f31000e5	79	dev_dbg(dev, "GPIO%d pull up enabled\n", m);
1a66fdf0 JC	80	amp->gpio_config(m, ~4, 4);
	81	break;
	82	case 'p':
f31000e5	83	dev_dbg(dev, "GPIO%d pull up disabled\n", m);
1a66fdf0 JC	84	amp->gpio_config(m, ~4, 0);
1a66fdf0 JC	85	break;
1a66fdf0 JC	86	case 'v':
1a66fdf0 JC	87	/* View Current pin settings */
f31000e5	88	amp->gpio_dump(amp, m);
1a66fdf0 JC	89	break;
	90	case '\n':
	91	/* end of settings string, do nothing */
	92	break;
	93	default:
f31000e5 JC	94	dev_err(dev, "io%2d bad setting: chr<0x%2x>\n",
f31000e5 JC	95	m, (int)c);
1a66fdf0 JC	96	err++;
	97	}
	98	}
	99	if (err)
	100	return -EINVAL; /* full string handled, report error */
	101
	102	return len;
	103	}
	104
	105	ssize_t nsc_gpio_read(struct file file, char __user buf,
	106	size_t len, loff_t * ppos)
	107	{
496ad9aa	108	unsigned m = iminor(file_inode(file));
1a66fdf0 JC	109	int value;
	110	struct nsc_gpio_ops *amp = file->private_data;
	111
	112	value = amp->gpio_get(m);
	113	if (put_user(value ? '1' : '0', buf))
	114	return -EFAULT;
	115
	116	return 1;
	117	}
	118
0e41ef3c	119	/* common file-ops routines for both scx200_gpio and pc87360_gpio */
1a66fdf0 JC	120	EXPORT_SYMBOL(nsc_gpio_write);
1a66fdf0 JC	121	EXPORT_SYMBOL(nsc_gpio_read);
0e41ef3c	122	EXPORT_SYMBOL(nsc_gpio_dump);
1ca5df0a JC	123
	124	static int __init nsc_gpio_init(void)
	125	{
	126	printk(KERN_DEBUG NAME " initializing\n");
	127	return 0;
	128	}
	129
	130	static void __exit nsc_gpio_cleanup(void)
	131	{
	132	printk(KERN_DEBUG NAME " cleanup\n");
	133	}
	134
1ca5df0a JC	135	module_init(nsc_gpio_init);
1ca5df0a JC	136	module_exit(nsc_gpio_cleanup);
1a66fdf0 JC	137
	138	MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");
	139	MODULE_DESCRIPTION("NatSemi GPIO Common Methods");
	140	MODULE_LICENSE("GPL");