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path: root/drivers/sbus/char/display7seg.c
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Diffstat (limited to 'drivers/sbus/char/display7seg.c')
-rw-r--r--drivers/sbus/char/display7seg.c234
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 00000000000..dbad7f35eb0
--- /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);