[mirror_ubuntu-zesty-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/io.h>

#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;
	cycle_kernel_lock();
	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_path.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 const 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_node->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 */
3049f89d	23	#include <asm/io.h>
1da177e4 LT	24
	25	#include <asm/display7seg.h>
	26
	27	#define D7S_MINOR 193
	28	#define D7S_OBPNAME "display7seg"
	29	#define D7S_DEVNAME "d7s"
	30
	31	static int sol_compat = 0; /* Solaris compatibility mode */
	32
	33	#ifdef MODULE
	34
	35	/* Solaris compatibility flag -
	36	* The Solaris implementation omits support for several
	37	* documented driver features (ref Sun doc 806-0180-03).
	38	* By default, this module supports the documented driver
	39	* abilities, rather than the Solaris implementation:
	40	*
	41	* 1) Device ALWAYS reverts to OBP-specified FLIPPED mode
	42	* upon closure of device or module unload.
	43	* 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of
	44	* FLIP bit
	45	*
	46	* If you wish the device to operate as under Solaris,
	47	* omitting above features, set this parameter to non-zero.
	48	*/
	49	module_param
	50	(sol_compat, int, 0);
	51	MODULE_PARM_DESC
	52	(sol_compat,
	53	"Disables documented functionality omitted from Solaris driver");
	54
	55	MODULE_AUTHOR
	56	("Eric Brower <ebrower@usa.net>");
	57	MODULE_DESCRIPTION
	58	("7-Segment Display driver for Sun Microsystems CP1400/1500");
	59	MODULE_LICENSE("GPL");
	60	MODULE_SUPPORTED_DEVICE
	61	("d7s");
	62	#endif /* ifdef MODULE */
	63
	64	/*
	65	* Register block address- see header for details
	66	* -----------------------------------------
	67	* \| DP \| ALARM \| FLIP \| 4 \| 3 \| 2 \| 1 \| 0 \|
	68	* -----------------------------------------
	69	*
	70	* DP - Toggles decimal point on/off
	71	* ALARM - Toggles "Alarm" LED green/red
	72	* FLIP - Inverts display for upside-down mounted board
	73	* bits 0-4 - 7-segment display contents
	74	*/
	75	static void __iomem* d7s_regs;
	76
	77	static inline void d7s_free(void)
	78	{
	79	iounmap(d7s_regs);
	80	}
	81
	82	static inline int d7s_obpflipped(void)
	83	{
	84	int opt_node;
	85
	86	opt_node = prom_getchild(prom_root_node);
	87	opt_node = prom_searchsiblings(opt_node, "options");
88	return ((-1 != prom_getintdefault(opt_node, "d7s-flipped?", -1)) ? 0 : 1);
89	}
90
91	static atomic_t d7s_users = ATOMIC_INIT(0);
92
93	static int d7s_open(struct inode inode, struct file f)
94	{
95	if (D7S_MINOR != iminor(inode))
96	return -ENODEV;
009228df	97	cycle_kernel_lock();
1da177e4 LT	98	atomic_inc(&d7s_users);
	99	return 0;
	100	}
	101
	102	static int d7s_release(struct inode inode, struct file f)
	103	{
	104	/* Reset flipped state to OBP default only if
	105	* no other users have the device open and we
	106	* are not operating in solaris-compat mode
	107	*/
	108	if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
	109	int regval = 0;
	110
	111	regval = readb(d7s_regs);
	112	(0 == d7s_obpflipped()) ?
	113	writeb(regval \|= D7S_FLIP, d7s_regs):
	114	writeb(regval &= ~D7S_FLIP, d7s_regs);
	115	}
	116
	117	return 0;
	118	}
	119
1d5d00bd	120	static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	121	{
	122	__u8 regs = readb(d7s_regs);
	123	__u8 ireg = 0;
a5aac37f	124	int error = 0;
1da177e4	125
7fa95f72	126	if (D7S_MINOR != iminor(file->f_path.dentry->d_inode))
1da177e4 LT	127	return -ENODEV;
1da177e4 LT	128
1d5d00bd	129	lock_kernel();
1da177e4 LT	130	switch (cmd) {
	131	case D7SIOCWR:
	132	/* assign device register values
	133	* we mask-out D7S_FLIP if in sol_compat mode
	134	*/
1d5d00bd CH	135	if (get_user(ireg, (int __user *) arg)) {
	136	error = -EFAULT;
	137	break;
	138	}
1da177e4 LT	139	if (0 != sol_compat) {
	140	(regs & D7S_FLIP) ?
	141	(ireg \|= D7S_FLIP) : (ireg &= ~D7S_FLIP);
	142	}
	143	writeb(ireg, d7s_regs);
	144	break;
	145
	146	case D7SIOCRD:
	147	/* retrieve device register values
	148	* NOTE: Solaris implementation returns D7S_FLIP bit
	149	* as toggled by user, even though it does not honor it.
	150	* This driver will not misinform you about the state
	151	* of your hardware while in sol_compat mode
	152	*/
1d5d00bd CH	153	if (put_user(regs, (int __user *) arg)) {
	154	error = -EFAULT;
	155	break;
	156	}
1da177e4 LT	157	break;
	158
	159	case D7SIOCTM:
	160	/* toggle device mode-- flip display orientation */
	161	(regs & D7S_FLIP) ?
	162	(regs &= ~D7S_FLIP) : (regs \|= D7S_FLIP);
	163	writeb(regs, d7s_regs);
	164	break;
	165	};
feee207e	166	unlock_kernel();
1da177e4	167
1d5d00bd	168	return error;
1da177e4 LT	169	}
1da177e4 LT	170
00977a59	171	static const struct file_operations d7s_fops = {
1d5d00bd CH	172	.owner = THIS_MODULE,
	173	.unlocked_ioctl = d7s_ioctl,
	174	.compat_ioctl = d7s_ioctl,
	175	.open = d7s_open,
	176	.release = d7s_release,
1da177e4 LT	177	};
	178
	179	static struct miscdevice d7s_miscdev = { D7S_MINOR, D7S_DEVNAME, &d7s_fops };
	180
	181	static int __init d7s_init(void)
	182	{
	183	struct linux_ebus *ebus = NULL;
	184	struct linux_ebus_device *edev = NULL;
	185	int iTmp = 0, regs = 0;
	186
	187	for_each_ebus(ebus) {
	188	for_each_ebusdev(edev, ebus) {
690c8fd3	189	if (!strcmp(edev->prom_node->name, D7S_OBPNAME))
1da177e4 LT	190	goto ebus_done;
	191	}
	192	}
	193
	194	ebus_done:
	195	if(!edev) {
	196	printk("%s: unable to locate device\n", D7S_DEVNAME);
	197	return -ENODEV;
	198	}
	199
	200	d7s_regs = ioremap(edev->resource[0].start, sizeof(__u8));
	201
	202	iTmp = misc_register(&d7s_miscdev);
	203	if (0 != iTmp) {
	204	printk("%s: unable to acquire miscdevice minor %i\n",
	205	D7S_DEVNAME, D7S_MINOR);
	206	iounmap(d7s_regs);
	207	return iTmp;
	208	}
	209
	210	/* OBP option "d7s-flipped?" is honored as default
	211	* for the device, and reset default when detached
	212	*/
	213	regs = readb(d7s_regs);
	214	iTmp = d7s_obpflipped();
	215	(0 == iTmp) ?
	216	writeb(regs \|= D7S_FLIP, d7s_regs):
	217	writeb(regs &= ~D7S_FLIP, d7s_regs);
	218
	219	printk("%s: 7-Segment Display%s at 0x%lx %s\n",
	220	D7S_DEVNAME,
	221	(0 == iTmp) ? (" (FLIPPED)") : (""),
	222	edev->resource[0].start,
	223	(0 != sol_compat) ? ("in sol_compat mode") : (""));
	224
	225	return 0;
	226	}
	227
	228	static void __exit d7s_cleanup(void)
	229	{
	230	int regs = readb(d7s_regs);
	231
	232	/* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
	233	if (0 == sol_compat) {
	234	(0 == d7s_obpflipped()) ?
	235	writeb(regs \|= D7S_FLIP, d7s_regs):
	236	writeb(regs &= ~D7S_FLIP, d7s_regs);
	237	}
	238
	239	misc_deregister(&d7s_miscdev);
	240	d7s_free();
	241	}
	242
	243	module_init(d7s_init);
	244	module_exit(d7s_cleanup);