[mirror_ubuntu-artful-kernel.git] / drivers / sbus / char / display7seg.c

/* $Id: display7seg.c,v 1.6 2002/01/08 16:00:16 davem Exp $
 *
 * display7seg - 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/smp_lock.h>
#include <asm/atomic.h>
#include <asm/ebus.h>			/* EBus device					*/
#include <asm/oplib.h>			/* OpenProm Library 			*/
#include <asm/uaccess.h>		/* put_/get_user			*/

#include <asm/display7seg.h>

#define D7S_MINOR	193
#define D7S_OBPNAME	"display7seg"
#define D7S_DEVNAME "d7s"

static int sol_compat = 0;		/* Solaris compatibility mode	*/

#ifdef MODULE

/* 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");
#endif /* ifdef MODULE */

/*
 * 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 void __iomem* d7s_regs;

static inline void d7s_free(void)
{
	iounmap(d7s_regs);
}

static inline int d7s_obpflipped(void)
{
	int opt_node;

	opt_node = prom_getchild(prom_root_node);
	opt_node = prom_searchsiblings(opt_node, "options");
	return ((-1 != prom_getintdefault(opt_node, "d7s-flipped?", -1)) ? 0 : 1);
}

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) {
		int regval = 0;

		regval = readb(d7s_regs);
		(0 == d7s_obpflipped())	? 
			writeb(regval |= D7S_FLIP,  d7s_regs): 
			writeb(regval &= ~D7S_FLIP, d7s_regs);
	}

	return 0;
}

static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	__u8 regs = readb(d7s_regs);
	__u8 ireg = 0;
	int error = 0

	if (D7S_MINOR != iminor(file->f_dentry->d_inode))
		return -ENODEV;

	lock_kernel();
	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 (0 != sol_compat) {
			(regs & D7S_FLIP) ? 
				(ireg |= D7S_FLIP) : (ireg &= ~D7S_FLIP);
		}
		writeb(ireg, d7s_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 */
		(regs & D7S_FLIP) ? 
			(regs &= ~D7S_FLIP) : (regs |= D7S_FLIP);
		writeb(regs, d7s_regs);
		break;
	};
	unlock_kernel();

	return error;
}

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

static struct miscdevice d7s_miscdev = { D7S_MINOR, D7S_DEVNAME, &d7s_fops };

static int __init d7s_init(void)
{
	struct linux_ebus *ebus = NULL;
	struct linux_ebus_device *edev = NULL;
	int iTmp = 0, regs = 0;

	for_each_ebus(ebus) {
		for_each_ebusdev(edev, ebus) {
			if (!strcmp(edev->prom_name, D7S_OBPNAME))
				goto ebus_done;
		}
	}

ebus_done:
	if(!edev) {
		printk("%s: unable to locate device\n", D7S_DEVNAME);
		return -ENODEV;
	}

	d7s_regs = ioremap(edev->resource[0].start, sizeof(__u8));

	iTmp = misc_register(&d7s_miscdev);
	if (0 != iTmp) {
		printk("%s: unable to acquire miscdevice minor %i\n",
		       D7S_DEVNAME, D7S_MINOR);
		iounmap(d7s_regs);
		return iTmp;
	}

	/* OBP option "d7s-flipped?" is honored as default
	 * for the device, and reset default when detached
	 */
	regs = readb(d7s_regs);
	iTmp = d7s_obpflipped();
	(0 == iTmp) ? 
		writeb(regs |= D7S_FLIP,  d7s_regs): 
		writeb(regs &= ~D7S_FLIP, d7s_regs);

	printk("%s: 7-Segment Display%s at 0x%lx %s\n", 
	       D7S_DEVNAME,
	       (0 == iTmp) ? (" (FLIPPED)") : (""),
	       edev->resource[0].start,
	       (0 != sol_compat) ? ("in sol_compat mode") : (""));

	return 0;
}

static void __exit d7s_cleanup(void)
{
	int regs = readb(d7s_regs);

	/* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
	if (0 == sol_compat) {
		(0 == d7s_obpflipped())	? 
			writeb(regs |= D7S_FLIP,  d7s_regs):
			writeb(regs &= ~D7S_FLIP, d7s_regs);
	}

	misc_deregister(&d7s_miscdev);
	d7s_free();
}

module_init(d7s_init);
module_exit(d7s_cleanup);
Commit	Line	Data
1da177e4 LT	1	/* $Id: display7seg.c,v 1.6 2002/01/08 16:00:16 davem Exp $
	2	*
	3	* display7seg - Driver implementation for the 7-segment display
	4	* present on Sun Microsystems CP1400 and CP1500
	5	*
	6	* Copyright (c) 2000 Eric Brower (ebrower@usa.net)
	7	*
	8	*/
	9
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/fs.h>
	13	#include <linux/errno.h>
	14	#include <linux/major.h>
	15	#include <linux/init.h>
	16	#include <linux/miscdevice.h>
fb911ee8	17	#include <linux/ioport.h> /* request_region */
1d5d00bd	18	#include <linux/smp_lock.h>
1da177e4 LT	19	#include <asm/atomic.h>
	20	#include <asm/ebus.h> /* EBus device */
	21	#include <asm/oplib.h> /* OpenProm Library */
	22	#include <asm/uaccess.h> /* put_/get_user */
	23
	24	#include <asm/display7seg.h>
	25
	26	#define D7S_MINOR 193
	27	#define D7S_OBPNAME "display7seg"
	28	#define D7S_DEVNAME "d7s"
	29
	30	static int sol_compat = 0; /* Solaris compatibility mode */
	31
	32	#ifdef MODULE
	33
	34	/* Solaris compatibility flag -
	35	* The Solaris implementation omits support for several
	36	* documented driver features (ref Sun doc 806-0180-03).
	37	* By default, this module supports the documented driver
	38	* abilities, rather than the Solaris implementation:
	39	*
	40	* 1) Device ALWAYS reverts to OBP-specified FLIPPED mode
	41	* upon closure of device or module unload.
	42	* 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of
	43	* FLIP bit
	44	*
	45	* If you wish the device to operate as under Solaris,
	46	* omitting above features, set this parameter to non-zero.
	47	*/
	48	module_param
	49	(sol_compat, int, 0);
	50	MODULE_PARM_DESC
	51	(sol_compat,
	52	"Disables documented functionality omitted from Solaris driver");
	53
	54	MODULE_AUTHOR
	55	("Eric Brower <ebrower@usa.net>");
	56	MODULE_DESCRIPTION
	57	("7-Segment Display driver for Sun Microsystems CP1400/1500");
	58	MODULE_LICENSE("GPL");
	59	MODULE_SUPPORTED_DEVICE
	60	("d7s");
	61	#endif /* ifdef MODULE */
	62
	63	/*
	64	* Register block address- see header for details
	65	* -----------------------------------------
	66	* \| DP \| ALARM \| FLIP \| 4 \| 3 \| 2 \| 1 \| 0 \|
	67	* -----------------------------------------
	68	*
	69	* DP - Toggles decimal point on/off
	70	* ALARM - Toggles "Alarm" LED green/red
	71	* FLIP - Inverts display for upside-down mounted board
	72	* bits 0-4 - 7-segment display contents
	73	*/
	74	static void __iomem* d7s_regs;
	75
	76	static inline void d7s_free(void)
	77	{
	78	iounmap(d7s_regs);
	79	}
	80
	81	static inline int d7s_obpflipped(void)
	82	{
83	int opt_node;
84
85	opt_node = prom_getchild(prom_root_node);
86	opt_node = prom_searchsiblings(opt_node, "options");
87	return ((-1 != prom_getintdefault(opt_node, "d7s-flipped?", -1)) ? 0 : 1);
88	}
89
90	static atomic_t d7s_users = ATOMIC_INIT(0);
91
92	static int d7s_open(struct inode inode, struct file f)
93	{
94	if (D7S_MINOR != iminor(inode))
95	return -ENODEV;
96	atomic_inc(&d7s_users);
97	return 0;
98	}
99
100	static int d7s_release(struct inode inode, struct file f)
101	{
102	/* Reset flipped state to OBP default only if
103	* no other users have the device open and we
104	* are not operating in solaris-compat mode
105	*/
106	if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
107	int regval = 0;
108
109	regval = readb(d7s_regs);
110	(0 == d7s_obpflipped()) ?
111	writeb(regval \|= D7S_FLIP, d7s_regs):
112	writeb(regval &= ~D7S_FLIP, d7s_regs);
113	}
114
115	return 0;
116	}
117
1d5d00bd	118	static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	119	{
	120	__u8 regs = readb(d7s_regs);
	121	__u8 ireg = 0;
1d5d00bd	122	int error = 0
1da177e4	123
1d5d00bd	124	if (D7S_MINOR != iminor(file->f_dentry->d_inode))
1da177e4 LT	125	return -ENODEV;
1da177e4 LT	126
1d5d00bd	127	lock_kernel();
1da177e4 LT	128	switch (cmd) {
	129	case D7SIOCWR:
	130	/* assign device register values
	131	* we mask-out D7S_FLIP if in sol_compat mode
	132	*/
1d5d00bd CH	133	if (get_user(ireg, (int __user *) arg)) {
	134	error = -EFAULT;
	135	break;
	136	}
1da177e4 LT	137	if (0 != sol_compat) {
	138	(regs & D7S_FLIP) ?
	139	(ireg \|= D7S_FLIP) : (ireg &= ~D7S_FLIP);
	140	}
	141	writeb(ireg, d7s_regs);
	142	break;
	143
	144	case D7SIOCRD:
	145	/* retrieve device register values
	146	* NOTE: Solaris implementation returns D7S_FLIP bit
	147	* as toggled by user, even though it does not honor it.
	148	* This driver will not misinform you about the state
	149	* of your hardware while in sol_compat mode
	150	*/
1d5d00bd CH	151	if (put_user(regs, (int __user *) arg)) {
	152	error = -EFAULT;
	153	break;
	154	}
1da177e4 LT	155	break;
	156
	157	case D7SIOCTM:
	158	/* toggle device mode-- flip display orientation */
	159	(regs & D7S_FLIP) ?
	160	(regs &= ~D7S_FLIP) : (regs \|= D7S_FLIP);
	161	writeb(regs, d7s_regs);
	162	break;
	163	};
feee207e	164	unlock_kernel();
1da177e4	165
1d5d00bd	166	return error;
1da177e4 LT	167	}
	168
	169	static struct file_operations d7s_fops = {
1d5d00bd CH	170	.owner = THIS_MODULE,
	171	.unlocked_ioctl = d7s_ioctl,
	172	.compat_ioctl = d7s_ioctl,
	173	.open = d7s_open,
	174	.release = d7s_release,
1da177e4 LT	175	};
	176
	177	static struct miscdevice d7s_miscdev = { D7S_MINOR, D7S_DEVNAME, &d7s_fops };
	178
	179	static int __init d7s_init(void)
	180	{
	181	struct linux_ebus *ebus = NULL;
	182	struct linux_ebus_device *edev = NULL;
	183	int iTmp = 0, regs = 0;
	184
	185	for_each_ebus(ebus) {
	186	for_each_ebusdev(edev, ebus) {
	187	if (!strcmp(edev->prom_name, D7S_OBPNAME))
	188	goto ebus_done;
	189	}
	190	}
	191
	192	ebus_done:
	193	if(!edev) {
	194	printk("%s: unable to locate device\n", D7S_DEVNAME);
	195	return -ENODEV;
	196	}
	197
	198	d7s_regs = ioremap(edev->resource[0].start, sizeof(__u8));
	199
	200	iTmp = misc_register(&d7s_miscdev);
	201	if (0 != iTmp) {
	202	printk("%s: unable to acquire miscdevice minor %i\n",
	203	D7S_DEVNAME, D7S_MINOR);
	204	iounmap(d7s_regs);
	205	return iTmp;
	206	}
	207
	208	/* OBP option "d7s-flipped?" is honored as default
	209	* for the device, and reset default when detached
	210	*/
	211	regs = readb(d7s_regs);
	212	iTmp = d7s_obpflipped();
	213	(0 == iTmp) ?
	214	writeb(regs \|= D7S_FLIP, d7s_regs):
	215	writeb(regs &= ~D7S_FLIP, d7s_regs);
	216
	217	printk("%s: 7-Segment Display%s at 0x%lx %s\n",
	218	D7S_DEVNAME,
	219	(0 == iTmp) ? (" (FLIPPED)") : (""),
	220	edev->resource[0].start,
	221	(0 != sol_compat) ? ("in sol_compat mode") : (""));
	222
	223	return 0;
	224	}
	225
	226	static void __exit d7s_cleanup(void)
	227	{
	228	int regs = readb(d7s_regs);
	229
	230	/* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
	231	if (0 == sol_compat) {
	232	(0 == d7s_obpflipped()) ?
	233	writeb(regs \|= D7S_FLIP, d7s_regs):
	234	writeb(regs &= ~D7S_FLIP, d7s_regs);
	235	}
	236
	237	misc_deregister(&d7s_miscdev);
	238	d7s_free();
239	}
240
241	module_init(d7s_init);
242	module_exit(d7s_cleanup);