1 files changed, 218 insertions, 0 deletions

diff --git a/drivers/input/serio/parkbd.c b/drivers/input/serio/parkbd.c
new file mode 100644
index 000000000000..1d15c2819818
--- /dev/null
+++ b/drivers/input/serio/parkbd.c
@@ -0,0 +1,218 @@
+/*
+ *  Parallel port to Keyboard port adapter driver for Linux
+ *
+ *  Copyright (c) 1999-2004 Vojtech Pavlik
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+/*
+ * To connect an AT or XT keyboard to the parallel port, a fairly simple adapter
+ * can be made:
+ * 
+ *  Parallel port            Keyboard port
+ *
+ *     +5V --------------------- +5V (4)
+ *  
+ *                 ______
+ *     +5V -------|______|--.
+ *                          |
+ *     ACK (10) ------------|
+ *                          |--- KBD CLOCK (5)
+ *     STROBE (1) ---|<|----'
+ *     
+ *                 ______
+ *     +5V -------|______|--.
+ *                          |
+ *     BUSY (11) -----------|
+ *                          |--- KBD DATA (1)
+ *     AUTOFD (14) --|<|----'
+ *
+ *     GND (18-25) ------------- GND (3)
+ *     
+ * The diodes can be fairly any type, and the resistors should be somewhere
+ * around 5 kOhm, but the adapter will likely work without the resistors,
+ * too.
+ *
+ * The +5V source can be taken either from USB, from mouse or keyboard ports,
+ * or from a joystick port. Unfortunately, the parallel port of a PC doesn't
+ * have a +5V pin, and feeding the keyboard from signal pins is out of question
+ * with 300 mA power reqirement of a typical AT keyboard.
+ */
+
+#include <linux/module.h>
+#include <linux/parport.h>
+#include <linux/init.h>
+#include <linux/serio.h>
+
+MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
+MODULE_DESCRIPTION("Parallel port to Keyboard port adapter driver");
+MODULE_LICENSE("GPL");
+
+static unsigned int parkbd_pp_no;
+module_param_named(port, parkbd_pp_no, int, 0);
+MODULE_PARM_DESC(port, "Parallel port the adapter is connected to (default is 0)");
+
+static unsigned int parkbd_mode = SERIO_8042;
+module_param_named(mode, parkbd_mode, uint, 0);
+MODULE_PARM_DESC(mode, "Mode of operation: XT = 0/AT = 1 (default)");
+
+#define PARKBD_CLOCK    0x01    /* Strobe & Ack */
+#define PARKBD_DATA     0x02    /* AutoFd & Busy */
+
+static int parkbd_buffer;
+static int parkbd_counter;
+static unsigned long parkbd_last;
+static int parkbd_writing;
+static unsigned long parkbd_start;
+
+static struct pardevice *parkbd_dev;
+static struct serio *parkbd_port;
+
+static int parkbd_readlines(void)
+{
+        return (parport_read_status(parkbd_dev->port) >> 6) ^ 2;
+}
+
+static void parkbd_writelines(int data)
+{
+        parport_write_control(parkbd_dev->port, (~data & 3) | 0x10);
+}
+
+static int parkbd_write(struct serio *port, unsigned char c)
+{
+        unsigned char p;
+
+        if (!parkbd_mode) return -1;
+
+        p = c ^ (c >> 4);
+        p = p ^ (p >> 2);
+        p = p ^ (p >> 1);
+
+        parkbd_counter = 0;
+        parkbd_writing = 1;
+        parkbd_buffer = c | (((int) (~p & 1)) << 8) | 0x600;
+
+        parkbd_writelines(2);
+
+        return 0;
+}
+
+static void parkbd_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+
+        if (parkbd_writing) {
+
+                if (parkbd_counter && ((parkbd_counter == 11) || time_after(jiffies, parkbd_last + HZ/100))) {
+                        parkbd_counter = 0;
+                        parkbd_buffer = 0;
+                        parkbd_writing = 0;
+                        parkbd_writelines(3);
+                        return;
+                }
+
+                parkbd_writelines(((parkbd_buffer >> parkbd_counter++) & 1) | 2);
+
+                if (parkbd_counter == 11) {
+                        parkbd_counter = 0;
+                        parkbd_buffer = 0;
+                        parkbd_writing = 0;
+                        parkbd_writelines(3);
+                }
+
+        } else {
+
+                if ((parkbd_counter == parkbd_mode + 10) || time_after(jiffies, parkbd_last + HZ/100)) {
+                        parkbd_counter = 0;
+                        parkbd_buffer = 0;
+                }
+
+                parkbd_buffer |= (parkbd_readlines() >> 1) << parkbd_counter++;
+
+                if (parkbd_counter == parkbd_mode + 10)
+                        serio_interrupt(parkbd_port, (parkbd_buffer >> (2 - parkbd_mode)) & 0xff, 0, regs);
+        }
+
+        parkbd_last = jiffies;
+}
+
+static int parkbd_getport(void)
+{
+        struct parport *pp;
+
+        pp = parport_find_number(parkbd_pp_no);
+
+        if (pp == NULL) {
+                printk(KERN_ERR "parkbd: no such parport\n");
+                return -ENODEV;
+        }
+
+        parkbd_dev = parport_register_device(pp, "parkbd", NULL, NULL, parkbd_interrupt, PARPORT_DEV_EXCL, NULL);
+        parport_put_port(pp);
+
+        if (!parkbd_dev)
+                return -ENODEV;
+
+        if (parport_claim(parkbd_dev)) {
+                parport_unregister_device(parkbd_dev);
+                return -EBUSY;
+        }
+
+        parkbd_start = jiffies;
+
+        return 0;
+}
+
+static struct serio * __init parkbd_allocate_serio(void)
+{
+        struct serio *serio;
+
+        serio = kmalloc(sizeof(struct serio), GFP_KERNEL);
+        if (serio) {
+                memset(serio, 0, sizeof(struct serio));
+                serio->id.type = parkbd_mode;
+                serio->write = parkbd_write,
+                strlcpy(serio->name, "PARKBD AT/XT keyboard adapter", sizeof(serio->name));
+                snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", parkbd_dev->port->name);
+        }
+
+        return serio;
+}
+
+static int __init parkbd_init(void)
+{
+        int err;
+
+        err = parkbd_getport();
+        if (err)
+                return err;
+
+        parkbd_port = parkbd_allocate_serio();
+        if (!parkbd_port) {
+                parport_release(parkbd_dev);
+                return -ENOMEM;
+        }
+
+        parkbd_writelines(3);
+
+        serio_register_port(parkbd_port);
+
+        printk(KERN_INFO "serio: PARKBD %s adapter on %s\n",
+                        parkbd_mode ? "AT" : "XT", parkbd_dev->port->name);
+
+        return 0;
+}
+
+static void __exit parkbd_exit(void)
+{
+        parport_release(parkbd_dev);
+        serio_unregister_port(parkbd_port);
+        parport_unregister_device(parkbd_dev);
+}
+
+module_init(parkbd_init);
+module_exit(parkbd_exit);