patch-2.3.31 linux/drivers/char/joystick/joy-magellan.c

• Lines: 398
• Date: Tue Dec 7 10:13:11 1999
• Orig file: v2.3.30/linux/drivers/char/joystick/joy-magellan.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.30/linux/drivers/char/joystick/joy-magellan.c linux/drivers/char/joystick/joy-magellan.c
@@ -0,0 +1,397 @@
+/*
+ *  joy-magellan.c  Version 0.1
+ *
+ *  Copyright (c) 1999 Vojtech Pavlik
+ *
+ *  Sponsored by SuSE
+ */
+
+/*
+ * This is a module for the Linux joystick driver, supporting
+ * the Magellan and Space Mouse 6dof controllers.
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or 
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * 
+ *  Should you need to contact me, the author, you can do so either by
+ * e-mail - mail your message to <vojtech@suse.cz>, or by paper mail:
+ * Vojtech Pavlik, Ucitelska 1576, Prague 8, 182 00 Czech Republic
+ */
+
+#include <asm/io.h>
+#include <asm/system.h>
+#include <linux/errno.h>
+#include <linux/joystick.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/tty.h>
+#include <linux/init.h>
+
+/*
+ * Constants.
+ */
+
+#define	N_JOYSTICK_MAG		14
+#define JS_MAG_MAX_LENGTH	64
+
+/*
+ * List of Magellans.
+ */
+
+static struct js_port* js_mag_port = NULL;
+
+/*
+ * Per-Magellan data.
+ */
+
+struct js_mag_info {
+	struct tty_struct* tty;
+	struct js_port* port;
+	int idx;
+	unsigned char data[JS_MAG_MAX_LENGTH];
+	unsigned char name[JS_MAG_MAX_LENGTH];
+	char ack;
+	char used;
+};
+
+/*
+ * js_mag_crunch_nibbles() verifies that the bytes sent from the Magellan
+ * have correct upper nibbles for the lower ones, if not, the packet will
+ * be thrown away. It also strips these upper halves to simplify further
+ * processing.
+ */
+
+static int js_mag_crunch_nibbles(unsigned char *data, int count)
+{
+	static unsigned char nibbles[16] = "0AB3D56GH9:K<MN?";
+
+	do {
+		if (data[count] == nibbles[data[count] & 0xf])
+			data[count] = data[count] & 0xf;
+		else
+			return -1;
+	} while (--count);
+
+	return 0;
+}
+
+/*
+ * js_mag_process_packet() decodes packets the driver receives from the
+ * Magellan. It updates the data accordingly, and sets an ACK flag
+ * to the type of last packet received, if received OK.
+ */
+
+static void js_mag_process_packet(struct js_mag_info* info)
+{
+	int i;
+
+	if (!info->idx) return;
+
+	switch (info->data[0]) {
+
+		case 'd':				/* Axis data */
+			if (info->idx != 25) return;
+			if (js_mag_crunch_nibbles(info->data, 24)) return;
+			if (!info->port->devs[0]) return;
+			for (i = 0; i < 6; i++) {
+				info->port->axes[0][i] = 
+					( info->data[(i << 2) + 1] << 12 | info->data[(i << 2) + 2] << 8 |
+					  info->data[(i << 2) + 3] <<  4 | info->data[(i << 2) + 4] )
+					 - 32768;
+			}
+			break;
+
+		case 'e':				/* Error packet */
+			if (info->idx != 4) return;
+			if (js_mag_crunch_nibbles(info->data, 3)) return;
+			switch (info->data[1]) {
+				case 1:
+					printk(KERN_ERR "joy-magellan: Received command error packet. Failing command byte: %c\n",
+						info->data[2] | (info->data[3] << 4));
+					break;
+				case 2:
+					printk(KERN_ERR "joy-magellan: Received framing error packet.\n");
+					break;
+				default:
+					printk(KERN_ERR "joy-magellan: Received unknown error packet.\n");
+			}
+			break;
+
+		case 'k':				/* Button data */
+			if (info->idx != 4) return;
+			if (js_mag_crunch_nibbles(info->data, 3)) return;
+			if (!info->port->devs[0]) return;
+			info->port->buttons[0][0] = (info->data[1] << 1) | (info->data[2] << 5) | info->data[3];
+			break;
+
+		case 'm':				/* Mode */
+			if (info->idx != 2) return;
+			if (js_mag_crunch_nibbles(info->data, 1)) return; 
+			break;
+
+		case 'n':				/* Null radius */
+			if (info->idx != 2) return;
+			if (js_mag_crunch_nibbles(info->data, 1)) return; 
+			break;
+
+		case 'p':				/* Data rate */
+			if (info->idx != 3) return;
+			if (js_mag_crunch_nibbles(info->data, 2)) return;
+			break;
+
+		case 'q':				/* Sensitivity */
+			if (info->idx != 3) return;
+			if (js_mag_crunch_nibbles(info->data, 2)) return; 
+			break;
+
+		case 'v':				/* Version string */
+			info->data[info->idx] = 0;
+			for (i = 1; i < info->idx && info->data[i] == ' '; i++);
+			memcpy(info->name, info->data + i, info->idx - i);
+			break;
+
+		case 'z':				/* Zero position */
+			break;
+
+		default:
+			printk("joy-magellan: Unknown packet %d length %d:", info->data[0], info->idx);
+			for (i = 0; i < info->idx; i++) printk(" %02x", info->data[i]);
+			printk("\n");
+			return;
+	}
+
+	info->ack = info->data[0];
+}
+
+/*
+ * js_mag_command() sends a command to the Magellan, and waits for
+ * acknowledge.
+ */
+
+static int js_mag_command(struct js_mag_info *info, char *command, int timeout)
+{
+	info->ack = 0;
+	if (info->tty->driver.write(info->tty, 0, command, strlen(command)) != strlen(command)) return -1;
+	while (!info->ack && timeout--) mdelay(1);
+	return -(info->ack != command[0]);
+}
+
+/*
+ * js_mag_setup() initializes the Magellan to sane state. Also works as
+ * a probe for Magellan existence.
+ */
+
+static int js_mag_setup(struct js_mag_info *info)
+{
+
+	if (js_mag_command(info, "vQ\r", 800))	/* Read version */
+		return -1;
+	if (js_mag_command(info, "m3\r", 50))	/* Set full 3d mode */
+		return -1;
+	if (js_mag_command(info, "pBB\r", 50))	/* Set 16 reports/second (max) */
+		return -1;
+	if (js_mag_command(info, "z\r", 50))	/* Set zero position */
+		return -1;
+
+	return 0;
+}
+
+/*
+ * js_mag_read() updates the axis and button data upon startup.
+ */
+
+static int js_mag_read(struct js_mag_info *info)
+{
+	memset(info->port->axes[0],0, sizeof(int) * 6);		/* Axes are 0 after zero postition cmd */ 
+
+	if (js_mag_command(info, "kQ\r", 50))			/* Read buttons */
+		return -1;
+
+	return 0;
+}
+
+/*
+ * js_mag_open() is a callback from the joystick device open routine.
+ */
+
+static int js_mag_open(struct js_dev *jd)
+{
+	struct js_mag_info *info = jd->port->info;
+	info->used++;	
+	MOD_INC_USE_COUNT;
+	return 0;
+}
+
+/*
+ * js_mag_close() is a callback from the joystick device release routine.
+ */
+
+static int js_mag_close(struct js_dev *jd)
+{
+	struct js_mag_info *info = jd->port->info;
+	if (!--info->used) {
+		js_unregister_device(jd->port->devs[0]);
+		js_mag_port = js_unregister_port(jd->port);
+	}
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+/*
+ * js_mag_init_corr() initializes the correction values for the Magellan.
+ * It asumes gain setting of 0, question is, what we should do for higher
+ * gain settings ...
+ */
+
+static void js_mag_init_corr(struct js_corr **corr)
+{
+	int i;
+
+	for (i = 0; i < 6; i++) {
+		corr[0][i].type = JS_CORR_BROKEN;
+		corr[0][i].prec = 0;
+		corr[0][i].coef[0] = 0;
+		corr[0][i].coef[1] = 0;
+		corr[0][i].coef[2] = (1 << 29) / 256;
+		corr[0][i].coef[3] = (1 << 29) / 256;
+	}
+}
+
+/*
+ * js_mag_ldisc_open() is the routine that is called upon setting our line
+ * discipline on a tty. It looks for the Magellan, and if found, registers
+ * it as a joystick device.
+ */
+
+static int js_mag_ldisc_open(struct tty_struct *tty)
+{
+	struct js_mag_info iniinfo;
+	struct js_mag_info *info = &iniinfo;
+
+	info->tty = tty;
+	info->idx = 0;
+	info->used = 1;
+
+	js_mag_port = js_register_port(js_mag_port, info, 1, sizeof(struct js_mag_info), NULL);
+
+	info = js_mag_port->info;
+	info->port = js_mag_port;
+	tty->disc_data = info;
+
+	if (js_mag_setup(info)) {
+		js_mag_port = js_unregister_port(info->port);
+		return -ENODEV;
+	}
+
+	printk(KERN_INFO "js%d: Magellan [%s] on %s%d\n",
+		js_register_device(js_mag_port, 0, 6, 9, "Magellan", js_mag_open, js_mag_close),
+		info->name, tty->driver.name, MINOR(tty->device) - tty->driver.minor_start);
+
+
+	js_mag_read(info);
+	js_mag_init_corr(js_mag_port->corr);
+
+	MOD_INC_USE_COUNT;
+
+	return 0;
+}
+
+/*
+ * js_mag_ldisc_close() is the opposite of js_mag_ldisc_open()
+ */
+
+static void js_mag_ldisc_close(struct tty_struct *tty)
+{
+	struct js_mag_info* info = (struct js_mag_info*) tty->disc_data;
+	if (!--info->used) {
+		js_unregister_device(info->port->devs[0]);
+		js_mag_port = js_unregister_port(info->port);
+	}
+	MOD_DEC_USE_COUNT;
+}
+
+/*
+ * js_mag_ldisc_receive() is called by the low level driver when characters
+ * are ready for us. We then buffer them for further processing, or call the
+ * packet processing routine.
+ */
+
+static void js_mag_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count)
+{
+	struct js_mag_info* info = (struct js_mag_info*) tty->disc_data;
+	int i;
+
+	for (i = 0; i < count; i++)
+		if (cp[i] == '\r') {
+			js_mag_process_packet(info);
+			info->idx = 0;
+		} else {
+			if (info->idx < JS_MAG_MAX_LENGTH)
+				info->data[info->idx++] = cp[i];
+		} 
+}
+
+/*
+ * js_mag_ldisc_room() reports how much room we do have for receiving data.
+ * Although we in fact have infinite room, we need to specify some value
+ * here, so why not the size of our packet buffer. It's big anyway.
+ */
+
+static int js_mag_ldisc_room(struct tty_struct *tty)
+{
+	return JS_MAG_MAX_LENGTH;
+}
+
+/*
+ * The line discipline structure.
+ */
+
+static struct tty_ldisc js_mag_ldisc = {
+        magic:          TTY_LDISC_MAGIC,
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0)
+        name:           "magellan",
+#endif
+	open:		js_mag_ldisc_open,
+	close:		js_mag_ldisc_close,
+	receive_buf:	js_mag_ldisc_receive,
+	receive_room:	js_mag_ldisc_room,
+};
+
+/*
+ * The functions for inserting/removing us as a module.
+ */
+
+#ifdef MODULE
+int init_module(void)
+#else
+int __init js_mag_init(void)
+#endif
+{
+        if (tty_register_ldisc(N_JOYSTICK_MAG, &js_mag_ldisc)) {
+                printk(KERN_ERR "joy-magellan: Error registering line discipline.\n");
+		return -ENODEV;
+	}
+
+	return  0;
+}
+
+#ifdef MODULE
+void cleanup_module(void)
+{
+	tty_register_ldisc(N_JOYSTICK_MAG, NULL);
+}
+#endif