drivers/parport/daisy.c

2  * IEEE 1284.3 Parallel port daisy chain and multiplexor code
12  * 31-01-1999: Make port-cloning transparent.
35 	struct parport *port;
45 static int mux_present(struct parport *port);
46 static int num_mux_ports(struct parport *port);
47 static int select_port(struct parport *port);
48 static int assign_addrs(struct parport *port);
51 static void add_dev(int devnum, struct parport *port, int daisy)
56 		newdev->port = port;
103 /* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
105 int parport_daisy_init(struct parport *port)
135 	/* If mux present on normal port, need to create new
136 	 * parports for each extra port. */
137 	if (port->muxport < 0 && mux_present(port) &&
139 	    ((num_ports = num_mux_ports(port)) == 2 || num_ports == 4)) {
140 		/* Leave original as port zero. */
141 		port->muxport = 0;
142 		pr_info("%s: 1st (default) port of %d-way multiplexor\n",
143 			port->name, num_ports);
145 			/* Clone the port. */
146 			struct parport *extra = clone_parport(port, i);
155 			pr_info("%s: %d%s port of %d-way multiplexor on %s\n",
157 				port->name);
159 			/* Analyse that port too.  We won't recurse
160 			   forever because of the 'port->muxport < 0'
166 	if (port->muxport >= 0)
167 		select_port(port);
169 	parport_daisy_deselect_all(port);
170 	detected += assign_addrs(port);
173 	add_dev(numdevs++, port, -1);
188 		parport_daisy_fini(port);
189 		parport_write_control(port, PARPORT_CONTROL_SELECT);
191 		parport_write_control(port,
202 /* Forget about devices on a physical port. */
203 void parport_daisy_fini(struct parport *port)
211 		if (dev->port != port) {
233  *	that it locates a device by its number rather than by the port
245 	struct parport *port;
260 	port = parport_get_port(p->port);
263 	dev = parport_register_dev_model(port, name, &par_cb, devnum);
264 	parport_put_port(port);
274 		selected = port->daisy;
301 static int cpp_daisy(struct parport *port, int cmd)
305 	parport_data_forward(port);
306 	parport_write_data(port, 0xaa); udelay(2);
307 	parport_write_data(port, 0x55); udelay(2);
308 	parport_write_data(port, 0x00); udelay(2);
309 	parport_write_data(port, 0xff); udelay(2);
310 	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
318 		pr_debug("%s: cpp_daisy: aa5500ff(%02x)\n", port->name, s);
322 	parport_write_data(port, 0x87); udelay(2);
323 	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
328 		pr_debug("%s: cpp_daisy: aa5500ff87(%02x)\n", port->name, s);
332 	parport_write_data(port, 0x78); udelay(2);
333 	parport_write_data(port, cmd); udelay(2);
334 	parport_frob_control(port,
338 	s = parport_read_status(port);
339 	parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
341 	parport_write_data(port, 0xff); udelay(2);
347 static int cpp_mux(struct parport *port, int cmd)
352 	parport_data_forward(port);
353 	parport_write_data(port, 0xaa); udelay(2);
354 	parport_write_data(port, 0x55); udelay(2);
355 	parport_write_data(port, 0xf0); udelay(2);
356 	parport_write_data(port, 0x0f); udelay(2);
357 	parport_write_data(port, 0x52); udelay(2);
358 	parport_write_data(port, 0xad); udelay(2);
359 	parport_write_data(port, cmd); udelay(2);
361 	s = parport_read_status(port);
364 			 port->name, cmd, s);
376 void parport_daisy_deselect_all(struct parport *port)
378 	cpp_daisy(port, 0x30);
381 int parport_daisy_select(struct parport *port, int daisy, int mode)
389 			return !(cpp_daisy(port, 0x20 + daisy) &
396 			return !(cpp_daisy(port, 0xd0 + daisy) &
407 			return !(cpp_daisy(port, 0xe0 + daisy) &
412 static int mux_present(struct parport *port)
414 	return cpp_mux(port, 0x51) == 3;
417 static int num_mux_ports(struct parport *port)
419 	return cpp_mux(port, 0x58);
422 static int select_port(struct parport *port)
424 	int muxport = port->muxport;
425 	return cpp_mux(port, 0x60 + muxport) == muxport;
428 static int assign_addrs(struct parport *port)
436 	parport_data_forward(port);
437 	parport_write_data(port, 0xaa); udelay(2);
438 	parport_write_data(port, 0x55); udelay(2);
439 	parport_write_data(port, 0x00); udelay(2);
440 	parport_write_data(port, 0xff); udelay(2);
441 	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
449 		pr_debug("%s: assign_addrs: aa5500ff(%02x)\n", port->name, s);
453 	parport_write_data(port, 0x87); udelay(2);
454 	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
459 		pr_debug("%s: assign_addrs: aa5500ff87(%02x)\n", port->name, s);
463 	parport_write_data(port, 0x78); udelay(2);
464 	s = parport_read_status(port);
471 		parport_write_data(port, daisy);
473 		parport_frob_control(port,
477 		parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
480 		add_dev(numdevs++, port, daisy);
491 		s = parport_read_status(port);
494 	parport_write_data(port, 0xff); udelay(2);
496 	pr_debug("%s: Found %d daisy-chained devices\n", port->name, detected);