[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / sbus / char / display7seg.c

/* display7seg.c - Driver implementation for the 7-segment display
 *                 present on Sun Microsystems CP1400 and CP1500
 *
 * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/major.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>		/* request_region */
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/atomic.h>
#include <asm/uaccess.h>		/* put_/get_user			*/
#include <asm/io.h>

#include <asm/display7seg.h>

#define D7S_MINOR	193
#define DRIVER_NAME	"d7s"
#define PFX		DRIVER_NAME ": "

static DEFINE_MUTEX(d7s_mutex);
static int sol_compat = 0;		/* Solaris compatibility mode	*/

/* Solaris compatibility flag -
 * The Solaris implementation omits support for several
 * documented driver features (ref Sun doc 806-0180-03).  
 * By default, this module supports the documented driver 
 * abilities, rather than the Solaris implementation:
 *
 * 	1) Device ALWAYS reverts to OBP-specified FLIPPED mode
 * 	   upon closure of device or module unload.
 * 	2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of
 * 	   FLIP bit
 *
 * If you wish the device to operate as under Solaris,
 * omitting above features, set this parameter to non-zero.
 */
module_param(sol_compat, int, 0);
MODULE_PARM_DESC(sol_compat, 
		 "Disables documented functionality omitted from Solaris driver");

MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("d7s");

struct d7s {
	void __iomem	*regs;
	bool		flipped;
};
struct d7s *d7s_device;

/*
 * Register block address- see header for details
 * -----------------------------------------
 * | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 |
 * -----------------------------------------
 *
 * DP 		- Toggles decimal point on/off 
 * ALARM	- Toggles "Alarm" LED green/red
 * FLIP		- Inverts display for upside-down mounted board
 * bits 0-4	- 7-segment display contents
 */
static atomic_t d7s_users = ATOMIC_INIT(0);

static int d7s_open(struct inode *inode, struct file *f)
{
	if (D7S_MINOR != iminor(inode))
		return -ENODEV;
	atomic_inc(&d7s_users);
	return 0;
}

static int d7s_release(struct inode *inode, struct file *f)
{
	/* Reset flipped state to OBP default only if
	 * no other users have the device open and we
	 * are not operating in solaris-compat mode
	 */
	if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
		struct d7s *p = d7s_device;
		u8 regval = 0;

		regval = readb(p->regs);
		if (p->flipped)
			regval |= D7S_FLIP;
		else
			regval &= ~D7S_FLIP;
		writeb(regval, p->regs);
	}

	return 0;
}

static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct d7s *p = d7s_device;
	u8 regs = readb(p->regs);
	int error = 0;
	u8 ireg = 0;

	if (D7S_MINOR != iminor(file->f_path.dentry->d_inode))
		return -ENODEV;

	mutex_lock(&d7s_mutex);
	switch (cmd) {
	case D7SIOCWR:
		/* assign device register values we mask-out D7S_FLIP
		 * if in sol_compat mode
		 */
		if (get_user(ireg, (int __user *) arg)) {
			error = -EFAULT;
			break;
		}
		if (sol_compat) {
			if (regs & D7S_FLIP)
				ireg |= D7S_FLIP;
			else
				ireg &= ~D7S_FLIP;
		}
		writeb(ireg, p->regs);
		break;

	case D7SIOCRD:
		/* retrieve device register values
		 * NOTE: Solaris implementation returns D7S_FLIP bit
		 * as toggled by user, even though it does not honor it.
		 * This driver will not misinform you about the state
		 * of your hardware while in sol_compat mode
		 */
		if (put_user(regs, (int __user *) arg)) {
			error = -EFAULT;
			break;
		}
		break;

	case D7SIOCTM:
		/* toggle device mode-- flip display orientation */
		if (regs & D7S_FLIP)
			regs &= ~D7S_FLIP;
		else
			regs |= D7S_FLIP;
		writeb(regs, p->regs);
		break;
	}
	mutex_unlock(&d7s_mutex);

	return error;
}

static const struct file_operations d7s_fops = {
	.owner =		THIS_MODULE,
	.unlocked_ioctl =	d7s_ioctl,
	.compat_ioctl =		d7s_ioctl,
	.open =			d7s_open,
	.release =		d7s_release,
	.llseek = noop_llseek,
};

static struct miscdevice d7s_miscdev = {
	.minor		= D7S_MINOR,
	.name		= DRIVER_NAME,
	.fops		= &d7s_fops
};

static int d7s_probe(struct platform_device *op)
{
	struct device_node *opts;
	int err = -EINVAL;
	struct d7s *p;
	u8 regs;

	if (d7s_device)
		goto out;

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	err = -ENOMEM;
	if (!p)
		goto out;

	p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s");
	if (!p->regs) {
		printk(KERN_ERR PFX "Cannot map chip registers\n");
		goto out_free;
	}

	err = misc_register(&d7s_miscdev);
	if (err) {
		printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n",
		       D7S_MINOR);
		goto out_iounmap;
	}

	/* OBP option "d7s-flipped?" is honored as default for the
	 * device, and reset default when detached
	 */
	regs = readb(p->regs);
	opts = of_find_node_by_path("/options");
	if (opts &&
	    of_get_property(opts, "d7s-flipped?", NULL))
		p->flipped = true;

	if (p->flipped)
		regs |= D7S_FLIP;
	else
		regs &= ~D7S_FLIP;

	writeb(regs,  p->regs);

	printk(KERN_INFO PFX "7-Segment Display%s at [%s:0x%llx] %s\n",
	       op->dev.of_node->full_name,
	       (regs & D7S_FLIP) ? " (FLIPPED)" : "",
	       op->resource[0].start,
	       sol_compat ? "in sol_compat mode" : "");

	dev_set_drvdata(&op->dev, p);
	d7s_device = p;
	err = 0;

out:
	return err;

out_iounmap:
	of_iounmap(&op->resource[0], p->regs, sizeof(u8));

out_free:
	kfree(p);
	goto out;
}

static int d7s_remove(struct platform_device *op)
{
	struct d7s *p = dev_get_drvdata(&op->dev);
	u8 regs = readb(p->regs);

	/* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
	if (sol_compat) {
		if (p->flipped)
			regs |= D7S_FLIP;
		else
			regs &= ~D7S_FLIP;
		writeb(regs, p->regs);
	}

	misc_deregister(&d7s_miscdev);
	of_iounmap(&op->resource[0], p->regs, sizeof(u8));
	kfree(p);

	return 0;
}

static const struct of_device_id d7s_match[] = {
	{
		.name = "display7seg",
	},
	{},
};
MODULE_DEVICE_TABLE(of, d7s_match);

static struct platform_driver d7s_driver = {
	.driver = {
		.name = DRIVER_NAME,
		.owner = THIS_MODULE,
		.of_match_table = d7s_match,
	},
	.probe		= d7s_probe,
	.remove		= d7s_remove,
};

module_platform_driver(d7s_driver);
Commit	Line	Data
95d43905 DM	1	/* display7seg.c - Driver implementation for the 7-segment display
95d43905 DM	2	* present on Sun Microsystems CP1400 and CP1500
1da177e4 LT	3	*
1da177e4 LT	4	* Copyright (c) 2000 Eric Brower (ebrower@usa.net)
1da177e4 LT	5	*/
	6
	7	#include <linux/kernel.h>
	8	#include <linux/module.h>
	9	#include <linux/fs.h>
	10	#include <linux/errno.h>
	11	#include <linux/major.h>
	12	#include <linux/init.h>
	13	#include <linux/miscdevice.h>
fb911ee8	14	#include <linux/ioport.h> /* request_region */
5a0e3ad6	15	#include <linux/slab.h>
a3108ca2	16	#include <linux/mutex.h>
95d43905 DM	17	#include <linux/of.h>
95d43905 DM	18	#include <linux/of_device.h>
60063497	19	#include <linux/atomic.h>
1da177e4	20	#include <asm/uaccess.h> /* put_/get_user */
3049f89d	21	#include <asm/io.h>
1da177e4 LT	22
	23	#include <asm/display7seg.h>
	24
	25	#define D7S_MINOR 193
95d43905 DM	26	#define DRIVER_NAME "d7s"
95d43905 DM	27	#define PFX DRIVER_NAME ": "
1da177e4	28
a3108ca2	29	static DEFINE_MUTEX(d7s_mutex);
1da177e4 LT	30	static int sol_compat = 0; /* Solaris compatibility mode */
1da177e4 LT	31
1da177e4 LT	32	/* Solaris compatibility flag -
	33	* The Solaris implementation omits support for several
	34	* documented driver features (ref Sun doc 806-0180-03).
	35	* By default, this module supports the documented driver
	36	* abilities, rather than the Solaris implementation:
	37	*
	38	* 1) Device ALWAYS reverts to OBP-specified FLIPPED mode
	39	* upon closure of device or module unload.
	40	* 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of
	41	* FLIP bit
	42	*
	43	* If you wish the device to operate as under Solaris,
	44	* omitting above features, set this parameter to non-zero.
	45	*/
95d43905 DM	46	module_param(sol_compat, int, 0);
	47	MODULE_PARM_DESC(sol_compat,
	48	"Disables documented functionality omitted from Solaris driver");
	49
	50	MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
	51	MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500");
1da177e4	52	MODULE_LICENSE("GPL");
95d43905 DM	53	MODULE_SUPPORTED_DEVICE("d7s");
	54
	55	struct d7s {
	56	void __iomem *regs;
	57	bool flipped;
	58	};
	59	struct d7s *d7s_device;
1da177e4 LT	60
	61	/*
	62	* Register block address- see header for details
	63	* -----------------------------------------
	64	* \| DP \| ALARM \| FLIP \| 4 \| 3 \| 2 \| 1 \| 0 \|
	65	* -----------------------------------------
	66	*
	67	* DP - Toggles decimal point on/off
	68	* ALARM - Toggles "Alarm" LED green/red
	69	* FLIP - Inverts display for upside-down mounted board
	70	* bits 0-4 - 7-segment display contents
	71	*/
1da177e4 LT	72	static atomic_t d7s_users = ATOMIC_INIT(0);
	73
	74	static int d7s_open(struct inode inode, struct file f)
	75	{
	76	if (D7S_MINOR != iminor(inode))
	77	return -ENODEV;
	78	atomic_inc(&d7s_users);
	79	return 0;
	80	}
	81
	82	static int d7s_release(struct inode inode, struct file f)
	83	{
	84	/* Reset flipped state to OBP default only if
	85	* no other users have the device open and we
	86	* are not operating in solaris-compat mode
	87	*/
	88	if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
95d43905 DM	89	struct d7s *p = d7s_device;
	90	u8 regval = 0;
	91
	92	regval = readb(p->regs);
	93	if (p->flipped)
	94	regval \|= D7S_FLIP;
	95	else
	96	regval &= ~D7S_FLIP;
	97	writeb(regval, p->regs);
1da177e4 LT	98	}
	99
	100	return 0;
	101	}
	102
1d5d00bd	103	static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4	104	{
95d43905 DM	105	struct d7s *p = d7s_device;
95d43905 DM	106	u8 regs = readb(p->regs);
a5aac37f	107	int error = 0;
95d43905	108	u8 ireg = 0;
1da177e4	109
7fa95f72	110	if (D7S_MINOR != iminor(file->f_path.dentry->d_inode))
1da177e4 LT	111	return -ENODEV;
1da177e4 LT	112
a3108ca2	113	mutex_lock(&d7s_mutex);
1da177e4 LT	114	switch (cmd) {
1da177e4 LT	115	case D7SIOCWR:
95d43905 DM	116	/* assign device register values we mask-out D7S_FLIP
95d43905 DM	117	* if in sol_compat mode
1da177e4	118	*/
1d5d00bd CH	119	if (get_user(ireg, (int __user *) arg)) {
	120	error = -EFAULT;
	121	break;
	122	}
95d43905 DM	123	if (sol_compat) {
	124	if (regs & D7S_FLIP)
	125	ireg \|= D7S_FLIP;
	126	else
	127	ireg &= ~D7S_FLIP;
1da177e4	128	}
95d43905	129	writeb(ireg, p->regs);
1da177e4 LT	130	break;
	131
	132	case D7SIOCRD:
	133	/* retrieve device register values
	134	* NOTE: Solaris implementation returns D7S_FLIP bit
	135	* as toggled by user, even though it does not honor it.
	136	* This driver will not misinform you about the state
	137	* of your hardware while in sol_compat mode
	138	*/
1d5d00bd CH	139	if (put_user(regs, (int __user *) arg)) {
	140	error = -EFAULT;
	141	break;
	142	}
1da177e4 LT	143	break;
	144
	145	case D7SIOCTM:
	146	/* toggle device mode-- flip display orientation */
95d43905 DM	147	if (regs & D7S_FLIP)
	148	regs &= ~D7S_FLIP;
	149	else
	150	regs \|= D7S_FLIP;
	151	writeb(regs, p->regs);
1da177e4	152	break;
da201161	153	}
a3108ca2	154	mutex_unlock(&d7s_mutex);
1da177e4	155
1d5d00bd	156	return error;
1da177e4 LT	157	}
1da177e4 LT	158
00977a59	159	static const struct file_operations d7s_fops = {
1d5d00bd CH	160	.owner = THIS_MODULE,
	161	.unlocked_ioctl = d7s_ioctl,
	162	.compat_ioctl = d7s_ioctl,
	163	.open = d7s_open,
	164	.release = d7s_release,
6038f373	165	.llseek = noop_llseek,
1da177e4 LT	166	};
1da177e4 LT	167
95d43905 DM	168	static struct miscdevice d7s_miscdev = {
	169	.minor = D7S_MINOR,
	170	.name = DRIVER_NAME,
	171	.fops = &d7s_fops
	172	};
1da177e4	173
082a2004	174	static int d7s_probe(struct platform_device *op)
1da177e4	175	{
95d43905 DM	176	struct device_node *opts;
	177	int err = -EINVAL;
	178	struct d7s *p;
	179	u8 regs;
	180
	181	if (d7s_device)
	182	goto out;
	183
	184	p = kzalloc(sizeof(*p), GFP_KERNEL);
	185	err = -ENOMEM;
	186	if (!p)
	187	goto out;
	188
	189	p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s");
	190	if (!p->regs) {
	191	printk(KERN_ERR PFX "Cannot map chip registers\n");
	192	goto out_free;
1da177e4 LT	193	}
1da177e4 LT	194
95d43905 DM	195	err = misc_register(&d7s_miscdev);
	196	if (err) {
	197	printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n",
	198	D7S_MINOR);
	199	goto out_iounmap;
1da177e4 LT	200	}
1da177e4 LT	201
95d43905 DM	202	/* OBP option "d7s-flipped?" is honored as default for the
95d43905 DM	203	* device, and reset default when detached
1da177e4	204	*/
95d43905 DM	205	regs = readb(p->regs);
	206	opts = of_find_node_by_path("/options");
	207	if (opts &&
	208	of_get_property(opts, "d7s-flipped?", NULL))
	209	p->flipped = true;
	210
	211	if (p->flipped)
	212	regs \|= D7S_FLIP;
	213	else
	214	regs &= ~D7S_FLIP;
	215
	216	writeb(regs, p->regs);
	217
3f4528d6	218	printk(KERN_INFO PFX "7-Segment Display%s at [%s:0x%llx] %s\n",
61c7a080	219	op->dev.of_node->full_name,
95d43905 DM	220	(regs & D7S_FLIP) ? " (FLIPPED)" : "",
	221	op->resource[0].start,
	222	sol_compat ? "in sol_compat mode" : "");
	223
	224	dev_set_drvdata(&op->dev, p);
	225	d7s_device = p;
	226	err = 0;
	227
	228	out:
	229	return err;
	230
	231	out_iounmap:
	232	of_iounmap(&op->resource[0], p->regs, sizeof(u8));
	233
	234	out_free:
	235	kfree(p);
	236	goto out;
1da177e4 LT	237	}
1da177e4 LT	238
082a2004	239	static int d7s_remove(struct platform_device *op)
1da177e4	240	{
95d43905 DM	241	struct d7s *p = dev_get_drvdata(&op->dev);
95d43905 DM	242	u8 regs = readb(p->regs);
1da177e4 LT	243
1da177e4 LT	244	/* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
95d43905 DM	245	if (sol_compat) {
	246	if (p->flipped)
	247	regs \|= D7S_FLIP;
	248	else
	249	regs &= ~D7S_FLIP;
	250	writeb(regs, p->regs);
1da177e4 LT	251	}
	252
	253	misc_deregister(&d7s_miscdev);
95d43905 DM	254	of_iounmap(&op->resource[0], p->regs, sizeof(u8));
	255	kfree(p);
	256
	257	return 0;
	258	}
	259
fd098316	260	static const struct of_device_id d7s_match[] = {
95d43905 DM	261	{
	262	.name = "display7seg",
	263	},
	264	{},
	265	};
	266	MODULE_DEVICE_TABLE(of, d7s_match);
	267
4ebb24f7	268	static struct platform_driver d7s_driver = {
4018294b GL	269	.driver = {
	270	.name = DRIVER_NAME,
	271	.owner = THIS_MODULE,
	272	.of_match_table = d7s_match,
	273	},
95d43905	274	.probe = d7s_probe,
082a2004	275	.remove = d7s_remove,
95d43905 DM	276	};
95d43905 DM	277
dbf2b92d	278	module_platform_driver(d7s_driver);