/* * Logitech Bus Mouse Driver for Linux * by James Banks * * Mods by Matthew Dillon *   calls verify_area() *   tracks better when X is busy or paging * * Heavily modified by David Giller *   changed from queue- to counter- driven *   hacked out a (probably incorrect) mouse_select * * Modified again by Nathan Laredo to interface with *   0.96c-pl1 IRQ handling changes (13JUL92) *   didn't bother touching select code. * * Modified the select() code blindly to conform to the VFS *   requirements. 92.07.14 - Linus. Somebody should test it out. * * Modified by Johan Myreen to make room for other mice (9AUG92) *   removed assignment chr_fops[10] = &mouse_fops; see mouse.c *   renamed mouse_fops => bus_mouse_fops, made bus_mouse_fops public. *   renamed this file mouse.c => busmouse.c */#include <linux/kernel.h>#include <linux/sched.h>#include <linux/busmouse.h>#include <linux/signal.h>#include <linux/errno.h>#include <asm/io.h>#include <asm/segment.h>#include <asm/system.h>#include <asm/irq.h>static struct mouse_status mouse;static int mouse_irq = MOUSE_IRQ;void bmouse_setup(char *str, int *ints){	if (ints[0] > 0)		mouse_irq=ints[1];}static void mouse_interrupt(int unused){	char dx, dy;	unsigned char buttons;	MSE_INT_OFF();	outb(MSE_READ_X_LOW, MSE_CONTROL_PORT);	dx = (inb(MSE_DATA_PORT) & 0xf);	outb(MSE_READ_X_HIGH, MSE_CONTROL_PORT);	dx |= (inb(MSE_DATA_PORT) & 0xf) << 4;	outb(MSE_READ_Y_LOW, MSE_CONTROL_PORT );	dy = (inb(MSE_DATA_PORT) & 0xf);	outb(MSE_READ_Y_HIGH, MSE_CONTROL_PORT);	buttons = inb(MSE_DATA_PORT);	dy |= (buttons & 0xf) << 4;	buttons = ((buttons >> 5) & 0x07);	if (dx != 0 || dy != 0 || buttons != mouse.buttons) {	  mouse.buttons = buttons;	  mouse.dx += dx;	  mouse.dy -= dy;	  mouse.ready = 1;	  wake_up_interruptible(&mouse.wait);	  /*	   * keep dx/dy reasonable, but still able to track when X (or	   * whatever) must page or is busy (i.e. long waits between	   * reads)	   */	  if (mouse.dx < -2048)	      mouse.dx = -2048;	  if (mouse.dx >  2048)	      mouse.dx =  2048;	  if (mouse.dy < -2048)	      mouse.dy = -2048;	  if (mouse.dy >  2048)	      mouse.dy =  2048;	}	MSE_INT_ON();}/* * close access to the mouse (can deal with multiple * opens if allowed in the future) */static void close_mouse(struct inode * inode, struct file * file){	if (--mouse.active == 0) {	    MSE_INT_OFF();	    free_irq(mouse_irq);	}}/* * open access to the mouse, currently only one open is * allowed. */static int open_mouse(struct inode * inode, struct file * file){	if (!mouse.present)		return -EINVAL;	if (mouse.active)		return -EBUSY;	mouse.ready = 0;	mouse.dx = 0;	mouse.dy = 0;	mouse.buttons = 0x87;	if (request_irq(mouse_irq, mouse_interrupt))		return -EBUSY;	mouse.active = 1;	MSE_INT_ON();	return 0;}/* * writes are disallowed */static int write_mouse(struct inode * inode, struct file * file, char * buffer, int count){	return -EINVAL;}/* * read mouse data.  Currently never blocks. */static int read_mouse(struct inode * inode, struct file * file, char * buffer, int count){	int r;	int dx;	int dy;	unsigned char buttons; 	if (count < 3)		return -EINVAL;	if ((r = verify_area(VERIFY_WRITE, buffer, count)))		return r;	if (!mouse.ready)		return -EAGAIN;	/*	 * Obtain the current mouse parameters and limit as appropriate for	 * the return data format.  Interrupts are only disabled while 	 * obtaining the parameters, NOT during the puts_fs_byte() calls,	 * so paging in put_fs_byte() does not effect mouse tracking.	 */	MSE_INT_OFF();	dx = mouse.dx;	dy = mouse.dy;	if (dx < -127)	    dx = -127;	if (dx > 127)	    dx = 127;	if (dy < -127)	    dy = -127;	if (dy > 127)	    dy = 127;	buttons = mouse.buttons;	mouse.dx -= dx;	mouse.dy -= dy;	mouse.ready = 0;	MSE_INT_ON();	put_fs_byte(buttons | 0x80, buffer);	put_fs_byte((char)dx, buffer + 1);	put_fs_byte((char)dy, buffer + 2);	for (r = 3; r < count; r++)	    put_fs_byte(0x00, buffer + r);	return r;}/* * select for mouse input, must disable the mouse interrupt while checking * mouse.ready/select_wait() to avoid race condition (though in reality * such a condition is not fatal to the proper operation of the mouse since * multiple interrupts generally occur). */static int mouse_select(struct inode *inode, struct file *file, int sel_type, select_table * wait){    int r = 0;    if (sel_type == SEL_IN) {    	MSE_INT_OFF();    	if (mouse.ready) {    	    r = 1;    	} else {	    select_wait(&mouse.wait, wait);    	}    	MSE_INT_ON();    }    return(r);}struct file_operations bus_mouse_fops = {	NULL,		/* mouse_seek */	read_mouse,	write_mouse,	NULL, 		/* mouse_readdir */	mouse_select, 	/* mouse_select */	NULL, 		/* mouse_ioctl */	NULL,		/* mouse_mmap */	open_mouse,	close_mouse,};unsigned long bus_mouse_init(unsigned long kmem_start){	int i;	outb(MSE_CONFIG_BYTE, MSE_CONFIG_PORT);	outb(MSE_SIGNATURE_BYTE, MSE_SIGNATURE_PORT);	for (i = 0; i < 100000; i++)		/* busy loop */;	if (inb(MSE_SIGNATURE_PORT) != MSE_SIGNATURE_BYTE) {		mouse.present = 0;		return kmem_start;	}	outb(MSE_DEFAULT_MODE, MSE_CONFIG_PORT);	MSE_INT_OFF();	mouse.present = 1;	mouse.active = 0;	mouse.ready = 0;	mouse.buttons = 0x87;	mouse.dx = 0;	mouse.dy = 0;	mouse.wait = NULL;	printk("Logitech Bus mouse detected and installed.\n");	return kmem_start;}