drivers/sbus/char/display7seg.c - maze/linux - Git at Google

 /* 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 <asm/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 __devinit d7s_probe(struct platform_device *op,
 			       const struct of_device_id *match)
 {
 	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 __devexit 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 of_platform_driver d7s_driver = {
 	.driver = {
 		.name = DRIVER_NAME,
 		.owner = THIS_MODULE,
 		.of_match_table = d7s_match,
 	},
 	.probe		= d7s_probe,
 	.remove		= __devexit_p(d7s_remove),
 };

 static int __init d7s_init(void)
 {
 	return of_register_platform_driver(&d7s_driver);
 }

 static void __exit d7s_exit(void)
 {
 	of_unregister_platform_driver(&d7s_driver);
 }

 module_init(d7s_init);
 module_exit(d7s_exit);
	/* 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 <asm/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 __devinit d7s_probe(struct platform_device *op,
	const struct of_device_id *match)
	{
	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 __devexit 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 of_platform_driver d7s_driver = {
	.driver = {
	.name = DRIVER_NAME,
	.owner = THIS_MODULE,
	.of_match_table = d7s_match,
	},
	.probe = d7s_probe,
	.remove = __devexit_p(d7s_remove),
	};

	static int __init d7s_init(void)
	{
	return of_register_platform_driver(&d7s_driver);
	}

	static void __exit d7s_exit(void)
	{
	of_unregister_platform_driver(&d7s_driver);
	}

	module_init(d7s_init);
	module_exit(d7s_exit);