patch-2.2.17 linux/drivers/sbus/char/display7seg.c

• Lines: 265
• Date: Mon Sep 4 18:39:20 2000
• Orig file: v2.2.16/drivers/sbus/char/display7seg.c
• Orig date: Thu Jan 1 01:00:00 1970

diff -u --recursive --new-file v2.2.16/drivers/sbus/char/display7seg.c linux/drivers/sbus/char/display7seg.c
@@ -0,0 +1,264 @@
+/* $Id: display7seg.c,v 1.1.2.1 2000/07/27 01:50:59 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/version.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, check_region */
+#include <asm/ebus.h>			/* EBus device			*/
+#include <asm/oplib.h>			/* OpenProm Library 		*/
+#include <asm/uaccess.h>		/* put_/get_user_ret		*/
+
+#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
+EXPORT_NO_SYMBOLS;
+
+/* 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_PARM
+	(sol_compat, "1i");
+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_SUPPORTED_DEVICE
+	("d7s");
+#endif /* ifdef MODULE */
+
+/*
+ * Register block- 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
+ */
+
+struct d7s_regs {
+	volatile __u8 regblk;
+};
+
+volatile struct d7s_regs *regs;
+
+static inline void d7s_free(void)
+{
+	release_region((unsigned long)regs, sizeof(*regs));
+}
+
+static inline int d7s_obpflipped(void)
+{
+	int opt_node, ret;
+
+	opt_node = prom_getchild(prom_root_node);
+	opt_node = prom_searchsiblings(opt_node, "options");
+
+	ret = prom_getintdefault(opt_node, "d7s-flipped?", -1);
+	if (ret != -1)
+		ret = 0;
+	else
+		ret = 1;
+
+	return ret;
+}
+
+static int d7s_open(struct inode *inode, struct file *f)
+{
+	if (D7S_MINOR != MINOR(inode->i_rdev))
+		return -ENODEV;
+
+	MOD_INC_USE_COUNT;
+	return 0;
+}
+
+static int d7s_release(struct inode *inode, struct file *f)
+{
+	if (D7S_MINOR != MINOR(inode->i_rdev))
+		return -ENODEV;
+	
+	MOD_DEC_USE_COUNT;
+
+	/* 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 (MOD_IN_USE == 0 && sol_compat == 0) {
+		if (d7s_obpflipped() == 0)
+			regs->regblk |= D7S_FLIP;
+		else
+			regs->regblk &= ~D7S_FLIP;
+	}
+
+	return 0;
+}
+
+static int d7s_ioctl(struct inode *inode, struct file *f, 
+		     unsigned int cmd, unsigned long arg)
+{
+	__u8 ireg = 0;
+
+	if (D7S_MINOR != MINOR(inode->i_rdev))
+		return -ENODEV;
+
+	switch (cmd) {
+	case D7SIOCWR:
+		/* Assign device register values,
+		 * we mask-out D7S_FLIP if in sol_compat mode.
+		 */
+		get_user_ret(ireg, (int *) arg, -EFAULT);
+		if (sol_compat != 0) {
+			if (regs->regblk & D7S_FLIP)
+				ireg |= D7S_FLIP;
+			else
+				ireg &= ~D7S_FLIP;
+		}
+		regs->regblk = ireg;
+		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.
+		 */
+		put_user_ret(regs->regblk, (int *) arg, -EFAULT);
+		break;
+	case D7SIOCTM:
+		/* Toggle device mode-- flip display orientation. */
+		if (regs->regblk & D7S_FLIP)
+			regs->regblk &= ~D7S_FLIP;
+		else
+			regs->regblk |= D7S_FLIP;
+		break;
+	};
+
+	return 0;
+}
+
+static struct file_operations d7s_fops = {
+	NULL,			/* lseek 		*/
+	NULL,			/* read			*/
+	NULL,			/* write		*/
+	NULL,			/* readdir		*/
+	NULL,			/* select 		*/
+	d7s_ioctl,
+	NULL,			/* mmap 		*/
+	d7s_open,
+	NULL,			/* flush 		*/
+	d7s_release,
+ 	NULL,			/* fsync 		*/
+	NULL,			/* fasync 		*/
+	NULL,			/* chk media chg*/
+	NULL,			/* revalidate 	*/
+ 	NULL,			/* lock 		*/
+};
+
+static struct miscdevice d7s_miscdev = { D7S_MINOR, D7S_DEVNAME, &d7s_fops };
+
+#ifdef MODULE
+int init_module(void)
+#else
+__initfunc(int d7s_init(void))
+#endif
+{
+	struct linux_ebus *ebus = NULL;
+	struct linux_ebus_device *edev = NULL;
+	int iTmp = 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;
+	}
+
+	if (check_region(edev->base_address[0], sizeof(*regs))) {
+		printk("%s: Can't get region %lx, %d\n",
+		       __FUNCTION__, edev->base_address[0], (int)sizeof(*regs));
+		return -ENODEV;
+	}
+
+	regs = (struct d7s_regs *) edev->base_address[0];
+	request_region((unsigned long) regs, sizeof(*regs), D7S_OBPNAME);
+	iTmp = misc_register(&d7s_miscdev);
+	if (iTmp != 0) {
+		printk("%s: unable to acquire miscdevice minor %i\n",
+		       D7S_DEVNAME, D7S_MINOR);
+		return iTmp;
+	}
+
+	/* OBP option "d7s-flipped?" is honored as default
+	 * for the device, and reset default when detached
+	 */
+	iTmp = d7s_obpflipped();
+	if (iTmp == 0)
+		regs->regblk |= D7S_FLIP;
+	else
+		regs->regblk &= ~D7S_FLIP;
+
+	printk("%s: 7-Segment Display%s at 0x%lx %s\n", 
+		D7S_DEVNAME,
+		(iTmp == 0) ? (" (FLIPPED)") : (""),
+		edev->base_address[0],
+		(sol_compat != 0) ? ("in sol_compat mode") : (""));
+	return 0;
+}
+
+#ifdef MODULE
+void cleanup_module(void)
+{
+	/* Honor OBP d7s-flipped? unless operating in solaris-compat mode. */
+	if (sol_compat == 0) {
+		if (d7s_obpflipped() == 0)
+			regs->regblk |= D7S_FLIP;
+		else
+			regs->regblk &= ~D7S_FLIP;
+	}
+
+	misc_deregister(&d7s_miscdev);
+	d7s_free();
+}
+#endif