2  * IEEE 1284.3 Parallel port daisy chain and multiplexor code
9  * 2 of the License, or (at your option) any later version.
11  * ??-12-1998: Initial implementation.
12  * 31-01-1999: Make port-cloning transparent.
13  * 13-02-1999: Move DeviceID technique from parport_probe.
14  * 13-03-1999: Get DeviceID from non-IEEE 1284.3 devices too.
15  * 22-02-2000: Count devices that are actually detected.
41 	struct parport *port;  member
49 /* Forward-declaration of lower-level functions. */
50 static int mux_present(struct parport *port);
51 static int num_mux_ports(struct parport *port);
52 static int select_port(struct parport *port);
53 static int assign_addrs(struct parport *port);
56 static void add_dev(int devnum, struct parport *port, int daisy)  in add_dev()  argument
61 		newdev->port = port;  in add_dev()
62 		newdev->daisy = daisy;  in add_dev()
63 		newdev->devnum = devnum;  in add_dev()
65 		for (p = &topology; *p && (*p)->devnum<devnum; p = &(*p)->next)  in add_dev()
67 		newdev->next = *p;  in add_dev()
76 	struct parport *extra = parport_register_port(real->base,  in clone_parport()
77 						       real->irq,  in clone_parport()
78 						       real->dma,  in clone_parport()
79 						       real->ops);  in clone_parport()
81 		extra->portnum = real->portnum;  in clone_parport()
82 		extra->physport = real;  in clone_parport()
83 		extra->muxport = muxport;  in clone_parport()
84 		real->slaves[muxport-1] = extra;  in clone_parport()
90 /* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
92 int parport_daisy_init(struct parport *port)  in parport_daisy_init()  argument
105 	/* If mux present on normal port, need to create new  in parport_daisy_init()
106 	 * parports for each extra port. */  in parport_daisy_init()
107 	if (port->muxport < 0 && mux_present(port) &&  in parport_daisy_init()
108 	    /* don't be fooled: a mux must have 2 or 4 ports. */  in parport_daisy_init()
109 	    ((num_ports = num_mux_ports(port)) == 2 || num_ports == 4)) {  in parport_daisy_init()
110 		/* Leave original as port zero. */  in parport_daisy_init()
111 		port->muxport = 0;  in parport_daisy_init()
113 			"%s: 1st (default) port of %d-way multiplexor\n",  in parport_daisy_init()
114 			port->name, num_ports);  in parport_daisy_init()
116 			/* Clone the port. */  in parport_daisy_init()
117 			struct parport *extra = clone_parport(port, i);  in parport_daisy_init()
127 				"%s: %d%s port of %d-way multiplexor on %s\n",  in parport_daisy_init()
128 				extra->name, i + 1, th[i + 1], num_ports,  in parport_daisy_init()
129 				port->name);  in parport_daisy_init()
131 			/* Analyse that port too.  We won't recurse  in parport_daisy_init()
132 			   forever because of the 'port->muxport < 0'  in parport_daisy_init()
138 	if (port->muxport >= 0)  in parport_daisy_init()
139 		select_port(port);  in parport_daisy_init()
141 	parport_daisy_deselect_all(port);  in parport_daisy_init()
142 	detected += assign_addrs(port);  in parport_daisy_init()
145 	add_dev(numdevs++, port, -1);  in parport_daisy_init()
150 		if (parport_device_id(numdevs - 1, deviceid, 1024) > 2)  in parport_daisy_init()
160 		parport_daisy_fini(port);  in parport_daisy_init()
161 		parport_write_control(port, PARPORT_CONTROL_SELECT);  in parport_daisy_init()
163 		parport_write_control(port,  in parport_daisy_init()
174 /* Forget about devices on a physical port. */
175 void parport_daisy_fini(struct parport *port)  in parport_daisy_fini()  argument
183 		if (dev->port != port) {  in parport_daisy_fini()
184 			p = &dev->next;  in parport_daisy_fini()
187 		*p = dev->next;  in parport_daisy_fini()
200  *	parport_open - find a device by canonical device number
205  *	that it locates a device by its number rather than by the port
216 	struct parport *port;  in parport_open()  local
221 	while (p && p->devnum != devnum)  in parport_open()
222 		p = p->next;  in parport_open()
229 	daisy = p->daisy;  in parport_open()
230 	port = parport_get_port(p->port);  in parport_open()
233 	dev = parport_register_device(port, name, NULL, NULL, NULL, 0, NULL);  in parport_open()
234 	parport_put_port(port);  in parport_open()
238 	dev->daisy = daisy;  in parport_open()
244 		selected = port->daisy;  in parport_open()
258  *	parport_close - close a device opened with parport_open()
270 /* Send a daisy-chain-style CPP command packet. */
271 static int cpp_daisy(struct parport *port, int cmd)  in cpp_daisy()  argument
275 	parport_data_forward(port);  in cpp_daisy()
276 	parport_write_data(port, 0xaa); udelay(2);  in cpp_daisy()
277 	parport_write_data(port, 0x55); udelay(2);  in cpp_daisy()
278 	parport_write_data(port, 0x00); udelay(2);  in cpp_daisy()
279 	parport_write_data(port, 0xff); udelay(2);  in cpp_daisy()
280 	s = parport_read_status(port) & (PARPORT_STATUS_BUSY  in cpp_daisy()
289 			 port->name, s);  in cpp_daisy()
290 		return -ENXIO;  in cpp_daisy()
293 	parport_write_data(port, 0x87); udelay(2);  in cpp_daisy()
294 	s = parport_read_status(port) & (PARPORT_STATUS_BUSY  in cpp_daisy()
300 			 port->name, s);  in cpp_daisy()
301 		return -ENXIO;  in cpp_daisy()
304 	parport_write_data(port, 0x78); udelay(2);  in cpp_daisy()
305 	parport_write_data(port, cmd); udelay(2);  in cpp_daisy()
306 	parport_frob_control(port,  in cpp_daisy()
310 	s = parport_read_status(port);  in cpp_daisy()
311 	parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);  in cpp_daisy()
313 	parport_write_data(port, 0xff); udelay(2);  in cpp_daisy()
318 /* Send a mux-style CPP command packet. */
319 static int cpp_mux(struct parport *port, int cmd)  in cpp_mux()  argument
324 	parport_data_forward(port);  in cpp_mux()
325 	parport_write_data(port, 0xaa); udelay(2);  in cpp_mux()
326 	parport_write_data(port, 0x55); udelay(2);  in cpp_mux()
327 	parport_write_data(port, 0xf0); udelay(2);  in cpp_mux()
328 	parport_write_data(port, 0x0f); udelay(2);  in cpp_mux()
329 	parport_write_data(port, 0x52); udelay(2);  in cpp_mux()
330 	parport_write_data(port, 0xad); udelay(2);  in cpp_mux()
331 	parport_write_data(port, cmd); udelay(2);  in cpp_mux()
333 	s = parport_read_status(port);  in cpp_mux()
336 			 port->name, cmd, s);  in cpp_mux()
337 		return -EIO;  in cpp_mux()
342 	      ((s & PARPORT_STATUS_BUSY     ? 0 : 1) << 2) |  in cpp_mux()
348 void parport_daisy_deselect_all(struct parport *port)  in parport_daisy_deselect_all()  argument
350 	cpp_daisy(port, 0x30);  in parport_daisy_deselect_all()
353 int parport_daisy_select(struct parport *port, int daisy, int mode)  in parport_daisy_select()  argument
361 			return !(cpp_daisy(port, 0x20 + daisy) &  in parport_daisy_select()
368 			return !(cpp_daisy(port, 0xd0 + daisy) &  in parport_daisy_select()
379 			return !(cpp_daisy(port, 0xe0 + daisy) &  in parport_daisy_select()
384 static int mux_present(struct parport *port)  in mux_present()  argument
386 	return cpp_mux(port, 0x51) == 3;  in mux_present()
389 static int num_mux_ports(struct parport *port)  in num_mux_ports()  argument
391 	return cpp_mux(port, 0x58);  in num_mux_ports()
394 static int select_port(struct parport *port)  in select_port()  argument
396 	int muxport = port->muxport;  in select_port()
397 	return cpp_mux(port, 0x60 + muxport) == muxport;  in select_port()
400 static int assign_addrs(struct parport *port)  in assign_addrs()  argument
408 	parport_data_forward(port);  in assign_addrs()
409 	parport_write_data(port, 0xaa); udelay(2);  in assign_addrs()
410 	parport_write_data(port, 0x55); udelay(2);  in assign_addrs()
411 	parport_write_data(port, 0x00); udelay(2);  in assign_addrs()
412 	parport_write_data(port, 0xff); udelay(2);  in assign_addrs()
413 	s = parport_read_status(port) & (PARPORT_STATUS_BUSY  in assign_addrs()
422 			 port->name, s);  in assign_addrs()
426 	parport_write_data(port, 0x87); udelay(2);  in assign_addrs()
427 	s = parport_read_status(port) & (PARPORT_STATUS_BUSY  in assign_addrs()
433 			 port->name, s);  in assign_addrs()
437 	parport_write_data(port, 0x78); udelay(2);  in assign_addrs()
438 	s = parport_read_status(port);  in assign_addrs()
445 		parport_write_data(port, daisy);  in assign_addrs()
446 		udelay(2);  in assign_addrs()
447 		parport_frob_control(port,  in assign_addrs()
451 		parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);  in assign_addrs()
454 		add_dev(numdevs++, port, daisy);  in assign_addrs()
463 		   work status lines from some non-daisy chain  in assign_addrs()
465 		s = parport_read_status(port);  in assign_addrs()
468 	parport_write_data(port, 0xff); udelay(2);  in assign_addrs()
469 	detected = numdevs - thisdev;  in assign_addrs()
470 	DPRINTK(KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name,  in assign_addrs()