1 files changed, 234 insertions, 0 deletions

diff --git a/drivers/sbus/char/display7seg.c b/drivers/sbus/char/display7seg.c
new file mode 100644
index 000000000000..dbad7f35eb0a
--- /dev/null
+++ b/drivers/sbus/char/display7seg.c
@@ -0,0 +1,234 @@
+/* $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, check_region */
+#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 int d7s_ioctl(struct inode *inode, struct file *f, 
+                     unsigned int cmd, unsigned long arg)
+{
+        __u8 regs = readb(d7s_regs);
+        __u8 ireg = 0;
+
+        if (D7S_MINOR != iminor(inode))
+                return -ENODEV;
+
+        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))
+                        return -EFAULT;
+                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))
+                        return -EFAULT;
+                break;
+
+        case D7SIOCTM:
+                /* toggle device mode-- flip display orientation */
+                (regs & D7S_FLIP) ? 
+                        (regs &= ~D7S_FLIP) : (regs |= D7S_FLIP);
+                writeb(regs, d7s_regs);
+                break;
+        };
+
+        return 0;
+}
+
+static struct file_operations d7s_fops = {
+        .owner =        THIS_MODULE,
+        .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);