xref: /openbmc/linux/arch/x86/kernel/early_printk.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 #include <linux/console.h>
2 #include <linux/kernel.h>
3 #include <linux/init.h>
4 #include <linux/string.h>
5 #include <linux/screen_info.h>
6 #include <linux/usb/ch9.h>
7 #include <linux/pci_regs.h>
8 #include <linux/pci_ids.h>
9 #include <linux/errno.h>
10 #include <asm/io.h>
11 #include <asm/processor.h>
12 #include <asm/fcntl.h>
13 #include <asm/setup.h>
14 #include <xen/hvc-console.h>
15 #include <asm/pci-direct.h>
16 #include <asm/fixmap.h>
17 #include <asm/pgtable.h>
18 #include <linux/usb/ehci_def.h>
19 
20 /* Simple VGA output */
21 #define VGABASE		(__ISA_IO_base + 0xb8000)
22 
23 static int max_ypos = 25, max_xpos = 80;
24 static int current_ypos = 25, current_xpos;
25 
26 static void early_vga_write(struct console *con, const char *str, unsigned n)
27 {
28 	char c;
29 	int  i, k, j;
30 
31 	while ((c = *str++) != '\0' && n-- > 0) {
32 		if (current_ypos >= max_ypos) {
33 			/* scroll 1 line up */
34 			for (k = 1, j = 0; k < max_ypos; k++, j++) {
35 				for (i = 0; i < max_xpos; i++) {
36 					writew(readw(VGABASE+2*(max_xpos*k+i)),
37 					       VGABASE + 2*(max_xpos*j + i));
38 				}
39 			}
40 			for (i = 0; i < max_xpos; i++)
41 				writew(0x720, VGABASE + 2*(max_xpos*j + i));
42 			current_ypos = max_ypos-1;
43 		}
44 		if (c == '\n') {
45 			current_xpos = 0;
46 			current_ypos++;
47 		} else if (c != '\r')  {
48 			writew(((0x7 << 8) | (unsigned short) c),
49 			       VGABASE + 2*(max_xpos*current_ypos +
50 						current_xpos++));
51 			if (current_xpos >= max_xpos) {
52 				current_xpos = 0;
53 				current_ypos++;
54 			}
55 		}
56 	}
57 }
58 
59 static struct console early_vga_console = {
60 	.name =		"earlyvga",
61 	.write =	early_vga_write,
62 	.flags =	CON_PRINTBUFFER,
63 	.index =	-1,
64 };
65 
66 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
67 
68 static int early_serial_base = 0x3f8;  /* ttyS0 */
69 
70 #define XMTRDY          0x20
71 
72 #define DLAB		0x80
73 
74 #define TXR             0       /*  Transmit register (WRITE) */
75 #define RXR             0       /*  Receive register  (READ)  */
76 #define IER             1       /*  Interrupt Enable          */
77 #define IIR             2       /*  Interrupt ID              */
78 #define FCR             2       /*  FIFO control              */
79 #define LCR             3       /*  Line control              */
80 #define MCR             4       /*  Modem control             */
81 #define LSR             5       /*  Line Status               */
82 #define MSR             6       /*  Modem Status              */
83 #define DLL             0       /*  Divisor Latch Low         */
84 #define DLH             1       /*  Divisor latch High        */
85 
86 static int early_serial_putc(unsigned char ch)
87 {
88 	unsigned timeout = 0xffff;
89 
90 	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
91 		cpu_relax();
92 	outb(ch, early_serial_base + TXR);
93 	return timeout ? 0 : -1;
94 }
95 
96 static void early_serial_write(struct console *con, const char *s, unsigned n)
97 {
98 	while (*s && n-- > 0) {
99 		if (*s == '\n')
100 			early_serial_putc('\r');
101 		early_serial_putc(*s);
102 		s++;
103 	}
104 }
105 
106 #define DEFAULT_BAUD 9600
107 
108 static __init void early_serial_init(char *s)
109 {
110 	unsigned char c;
111 	unsigned divisor;
112 	unsigned baud = DEFAULT_BAUD;
113 	char *e;
114 
115 	if (*s == ',')
116 		++s;
117 
118 	if (*s) {
119 		unsigned port;
120 		if (!strncmp(s, "0x", 2)) {
121 			early_serial_base = simple_strtoul(s, &e, 16);
122 		} else {
123 			static const int __initconst bases[] = { 0x3f8, 0x2f8 };
124 
125 			if (!strncmp(s, "ttyS", 4))
126 				s += 4;
127 			port = simple_strtoul(s, &e, 10);
128 			if (port > 1 || s == e)
129 				port = 0;
130 			early_serial_base = bases[port];
131 		}
132 		s += strcspn(s, ",");
133 		if (*s == ',')
134 			s++;
135 	}
136 
137 	outb(0x3, early_serial_base + LCR);	/* 8n1 */
138 	outb(0, early_serial_base + IER);	/* no interrupt */
139 	outb(0, early_serial_base + FCR);	/* no fifo */
140 	outb(0x3, early_serial_base + MCR);	/* DTR + RTS */
141 
142 	if (*s) {
143 		baud = simple_strtoul(s, &e, 0);
144 		if (baud == 0 || s == e)
145 			baud = DEFAULT_BAUD;
146 	}
147 
148 	divisor = 115200 / baud;
149 	c = inb(early_serial_base + LCR);
150 	outb(c | DLAB, early_serial_base + LCR);
151 	outb(divisor & 0xff, early_serial_base + DLL);
152 	outb((divisor >> 8) & 0xff, early_serial_base + DLH);
153 	outb(c & ~DLAB, early_serial_base + LCR);
154 }
155 
156 static struct console early_serial_console = {
157 	.name =		"earlyser",
158 	.write =	early_serial_write,
159 	.flags =	CON_PRINTBUFFER,
160 	.index =	-1,
161 };
162 
163 #ifdef CONFIG_EARLY_PRINTK_DBGP
164 
165 static struct ehci_caps __iomem *ehci_caps;
166 static struct ehci_regs __iomem *ehci_regs;
167 static struct ehci_dbg_port __iomem *ehci_debug;
168 static unsigned int dbgp_endpoint_out;
169 
170 struct ehci_dev {
171 	u32 bus;
172 	u32 slot;
173 	u32 func;
174 };
175 
176 static struct ehci_dev ehci_dev;
177 
178 #define USB_DEBUG_DEVNUM 127
179 
180 #define DBGP_DATA_TOGGLE	0x8800
181 
182 static inline u32 dbgp_pid_update(u32 x, u32 tok)
183 {
184 	return ((x ^ DBGP_DATA_TOGGLE) & 0xffff00) | (tok & 0xff);
185 }
186 
187 static inline u32 dbgp_len_update(u32 x, u32 len)
188 {
189 	return (x & ~0x0f) | (len & 0x0f);
190 }
191 
192 /*
193  * USB Packet IDs (PIDs)
194  */
195 
196 /* token */
197 #define USB_PID_OUT		0xe1
198 #define USB_PID_IN		0x69
199 #define USB_PID_SOF		0xa5
200 #define USB_PID_SETUP		0x2d
201 /* handshake */
202 #define USB_PID_ACK		0xd2
203 #define USB_PID_NAK		0x5a
204 #define USB_PID_STALL		0x1e
205 #define USB_PID_NYET		0x96
206 /* data */
207 #define USB_PID_DATA0		0xc3
208 #define USB_PID_DATA1		0x4b
209 #define USB_PID_DATA2		0x87
210 #define USB_PID_MDATA		0x0f
211 /* Special */
212 #define USB_PID_PREAMBLE	0x3c
213 #define USB_PID_ERR		0x3c
214 #define USB_PID_SPLIT		0x78
215 #define USB_PID_PING		0xb4
216 #define USB_PID_UNDEF_0		0xf0
217 
218 #define USB_PID_DATA_TOGGLE	0x88
219 #define DBGP_CLAIM (DBGP_OWNER | DBGP_ENABLED | DBGP_INUSE)
220 
221 #define PCI_CAP_ID_EHCI_DEBUG	0xa
222 
223 #define HUB_ROOT_RESET_TIME	50	/* times are in msec */
224 #define HUB_SHORT_RESET_TIME	10
225 #define HUB_LONG_RESET_TIME	200
226 #define HUB_RESET_TIMEOUT	500
227 
228 #define DBGP_MAX_PACKET		8
229 
230 static int dbgp_wait_until_complete(void)
231 {
232 	u32 ctrl;
233 	int loop = 0x100000;
234 
235 	do {
236 		ctrl = readl(&ehci_debug->control);
237 		/* Stop when the transaction is finished */
238 		if (ctrl & DBGP_DONE)
239 			break;
240 	} while (--loop > 0);
241 
242 	if (!loop)
243 		return -1;
244 
245 	/*
246 	 * Now that we have observed the completed transaction,
247 	 * clear the done bit.
248 	 */
249 	writel(ctrl | DBGP_DONE, &ehci_debug->control);
250 	return (ctrl & DBGP_ERROR) ? -DBGP_ERRCODE(ctrl) : DBGP_LEN(ctrl);
251 }
252 
253 static void __init dbgp_mdelay(int ms)
254 {
255 	int i;
256 
257 	while (ms--) {
258 		for (i = 0; i < 1000; i++)
259 			outb(0x1, 0x80);
260 	}
261 }
262 
263 static void dbgp_breath(void)
264 {
265 	/* Sleep to give the debug port a chance to breathe */
266 }
267 
268 static int dbgp_wait_until_done(unsigned ctrl)
269 {
270 	u32 pids, lpid;
271 	int ret;
272 	int loop = 3;
273 
274 retry:
275 	writel(ctrl | DBGP_GO, &ehci_debug->control);
276 	ret = dbgp_wait_until_complete();
277 	pids = readl(&ehci_debug->pids);
278 	lpid = DBGP_PID_GET(pids);
279 
280 	if (ret < 0)
281 		return ret;
282 
283 	/*
284 	 * If the port is getting full or it has dropped data
285 	 * start pacing ourselves, not necessary but it's friendly.
286 	 */
287 	if ((lpid == USB_PID_NAK) || (lpid == USB_PID_NYET))
288 		dbgp_breath();
289 
290 	/* If I get a NACK reissue the transmission */
291 	if (lpid == USB_PID_NAK) {
292 		if (--loop > 0)
293 			goto retry;
294 	}
295 
296 	return ret;
297 }
298 
299 static void dbgp_set_data(const void *buf, int size)
300 {
301 	const unsigned char *bytes = buf;
302 	u32 lo, hi;
303 	int i;
304 
305 	lo = hi = 0;
306 	for (i = 0; i < 4 && i < size; i++)
307 		lo |= bytes[i] << (8*i);
308 	for (; i < 8 && i < size; i++)
309 		hi |= bytes[i] << (8*(i - 4));
310 	writel(lo, &ehci_debug->data03);
311 	writel(hi, &ehci_debug->data47);
312 }
313 
314 static void __init dbgp_get_data(void *buf, int size)
315 {
316 	unsigned char *bytes = buf;
317 	u32 lo, hi;
318 	int i;
319 
320 	lo = readl(&ehci_debug->data03);
321 	hi = readl(&ehci_debug->data47);
322 	for (i = 0; i < 4 && i < size; i++)
323 		bytes[i] = (lo >> (8*i)) & 0xff;
324 	for (; i < 8 && i < size; i++)
325 		bytes[i] = (hi >> (8*(i - 4))) & 0xff;
326 }
327 
328 static int dbgp_bulk_write(unsigned devnum, unsigned endpoint,
329 			 const char *bytes, int size)
330 {
331 	u32 pids, addr, ctrl;
332 	int ret;
333 
334 	if (size > DBGP_MAX_PACKET)
335 		return -1;
336 
337 	addr = DBGP_EPADDR(devnum, endpoint);
338 
339 	pids = readl(&ehci_debug->pids);
340 	pids = dbgp_pid_update(pids, USB_PID_OUT);
341 
342 	ctrl = readl(&ehci_debug->control);
343 	ctrl = dbgp_len_update(ctrl, size);
344 	ctrl |= DBGP_OUT;
345 	ctrl |= DBGP_GO;
346 
347 	dbgp_set_data(bytes, size);
348 	writel(addr, &ehci_debug->address);
349 	writel(pids, &ehci_debug->pids);
350 
351 	ret = dbgp_wait_until_done(ctrl);
352 	if (ret < 0)
353 		return ret;
354 
355 	return ret;
356 }
357 
358 static int __init dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data,
359 				 int size)
360 {
361 	u32 pids, addr, ctrl;
362 	int ret;
363 
364 	if (size > DBGP_MAX_PACKET)
365 		return -1;
366 
367 	addr = DBGP_EPADDR(devnum, endpoint);
368 
369 	pids = readl(&ehci_debug->pids);
370 	pids = dbgp_pid_update(pids, USB_PID_IN);
371 
372 	ctrl = readl(&ehci_debug->control);
373 	ctrl = dbgp_len_update(ctrl, size);
374 	ctrl &= ~DBGP_OUT;
375 	ctrl |= DBGP_GO;
376 
377 	writel(addr, &ehci_debug->address);
378 	writel(pids, &ehci_debug->pids);
379 	ret = dbgp_wait_until_done(ctrl);
380 	if (ret < 0)
381 		return ret;
382 
383 	if (size > ret)
384 		size = ret;
385 	dbgp_get_data(data, size);
386 	return ret;
387 }
388 
389 static int __init dbgp_control_msg(unsigned devnum, int requesttype,
390 	int request, int value, int index, void *data, int size)
391 {
392 	u32 pids, addr, ctrl;
393 	struct usb_ctrlrequest req;
394 	int read;
395 	int ret;
396 
397 	read = (requesttype & USB_DIR_IN) != 0;
398 	if (size > (read ? DBGP_MAX_PACKET:0))
399 		return -1;
400 
401 	/* Compute the control message */
402 	req.bRequestType = requesttype;
403 	req.bRequest = request;
404 	req.wValue = cpu_to_le16(value);
405 	req.wIndex = cpu_to_le16(index);
406 	req.wLength = cpu_to_le16(size);
407 
408 	pids = DBGP_PID_SET(USB_PID_DATA0, USB_PID_SETUP);
409 	addr = DBGP_EPADDR(devnum, 0);
410 
411 	ctrl = readl(&ehci_debug->control);
412 	ctrl = dbgp_len_update(ctrl, sizeof(req));
413 	ctrl |= DBGP_OUT;
414 	ctrl |= DBGP_GO;
415 
416 	/* Send the setup message */
417 	dbgp_set_data(&req, sizeof(req));
418 	writel(addr, &ehci_debug->address);
419 	writel(pids, &ehci_debug->pids);
420 	ret = dbgp_wait_until_done(ctrl);
421 	if (ret < 0)
422 		return ret;
423 
424 	/* Read the result */
425 	return dbgp_bulk_read(devnum, 0, data, size);
426 }
427 
428 
429 /* Find a PCI capability */
430 static u32 __init find_cap(u32 num, u32 slot, u32 func, int cap)
431 {
432 	u8 pos;
433 	int bytes;
434 
435 	if (!(read_pci_config_16(num, slot, func, PCI_STATUS) &
436 		PCI_STATUS_CAP_LIST))
437 		return 0;
438 
439 	pos = read_pci_config_byte(num, slot, func, PCI_CAPABILITY_LIST);
440 	for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
441 		u8 id;
442 
443 		pos &= ~3;
444 		id = read_pci_config_byte(num, slot, func, pos+PCI_CAP_LIST_ID);
445 		if (id == 0xff)
446 			break;
447 		if (id == cap)
448 			return pos;
449 
450 		pos = read_pci_config_byte(num, slot, func,
451 						 pos+PCI_CAP_LIST_NEXT);
452 	}
453 	return 0;
454 }
455 
456 static u32 __init __find_dbgp(u32 bus, u32 slot, u32 func)
457 {
458 	u32 class;
459 
460 	class = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
461 	if ((class >> 8) != PCI_CLASS_SERIAL_USB_EHCI)
462 		return 0;
463 
464 	return find_cap(bus, slot, func, PCI_CAP_ID_EHCI_DEBUG);
465 }
466 
467 static u32 __init find_dbgp(int ehci_num, u32 *rbus, u32 *rslot, u32 *rfunc)
468 {
469 	u32 bus, slot, func;
470 
471 	for (bus = 0; bus < 256; bus++) {
472 		for (slot = 0; slot < 32; slot++) {
473 			for (func = 0; func < 8; func++) {
474 				unsigned cap;
475 
476 				cap = __find_dbgp(bus, slot, func);
477 
478 				if (!cap)
479 					continue;
480 				if (ehci_num-- != 0)
481 					continue;
482 				*rbus = bus;
483 				*rslot = slot;
484 				*rfunc = func;
485 				return cap;
486 			}
487 		}
488 	}
489 	return 0;
490 }
491 
492 static int __init ehci_reset_port(int port)
493 {
494 	u32 portsc;
495 	u32 delay_time, delay;
496 	int loop;
497 
498 	/* Reset the usb debug port */
499 	portsc = readl(&ehci_regs->port_status[port - 1]);
500 	portsc &= ~PORT_PE;
501 	portsc |= PORT_RESET;
502 	writel(portsc, &ehci_regs->port_status[port - 1]);
503 
504 	delay = HUB_ROOT_RESET_TIME;
505 	for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT;
506 	     delay_time += delay) {
507 		dbgp_mdelay(delay);
508 
509 		portsc = readl(&ehci_regs->port_status[port - 1]);
510 		if (portsc & PORT_RESET) {
511 			/* force reset to complete */
512 			loop = 2;
513 			writel(portsc & ~(PORT_RWC_BITS | PORT_RESET),
514 				&ehci_regs->port_status[port - 1]);
515 			do {
516 				portsc = readl(&ehci_regs->port_status[port-1]);
517 			} while ((portsc & PORT_RESET) && (--loop > 0));
518 		}
519 
520 		/* Device went away? */
521 		if (!(portsc & PORT_CONNECT))
522 			return -ENOTCONN;
523 
524 		/* bomb out completely if something weird happend */
525 		if ((portsc & PORT_CSC))
526 			return -EINVAL;
527 
528 		/* If we've finished resetting, then break out of the loop */
529 		if (!(portsc & PORT_RESET) && (portsc & PORT_PE))
530 			return 0;
531 	}
532 	return -EBUSY;
533 }
534 
535 static int __init ehci_wait_for_port(int port)
536 {
537 	u32 status;
538 	int ret, reps;
539 
540 	for (reps = 0; reps < 3; reps++) {
541 		dbgp_mdelay(100);
542 		status = readl(&ehci_regs->status);
543 		if (status & STS_PCD) {
544 			ret = ehci_reset_port(port);
545 			if (ret == 0)
546 				return 0;
547 		}
548 	}
549 	return -ENOTCONN;
550 }
551 
552 #ifdef DBGP_DEBUG
553 # define dbgp_printk early_printk
554 #else
555 static inline void dbgp_printk(const char *fmt, ...) { }
556 #endif
557 
558 typedef void (*set_debug_port_t)(int port);
559 
560 static void __init default_set_debug_port(int port)
561 {
562 }
563 
564 static set_debug_port_t __initdata set_debug_port = default_set_debug_port;
565 
566 static void __init nvidia_set_debug_port(int port)
567 {
568 	u32 dword;
569 	dword = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
570 				 0x74);
571 	dword &= ~(0x0f<<12);
572 	dword |= ((port & 0x0f)<<12);
573 	write_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, 0x74,
574 				 dword);
575 	dbgp_printk("set debug port to %d\n", port);
576 }
577 
578 static void __init detect_set_debug_port(void)
579 {
580 	u32 vendorid;
581 
582 	vendorid = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
583 		 0x00);
584 
585 	if ((vendorid & 0xffff) == 0x10de) {
586 		dbgp_printk("using nvidia set_debug_port\n");
587 		set_debug_port = nvidia_set_debug_port;
588 	}
589 }
590 
591 static int __init ehci_setup(void)
592 {
593 	struct usb_debug_descriptor dbgp_desc;
594 	u32 cmd, ctrl, status, portsc, hcs_params;
595 	u32 debug_port, new_debug_port = 0, n_ports;
596 	u32  devnum;
597 	int ret, i;
598 	int loop;
599 	int port_map_tried;
600 	int playtimes = 3;
601 
602 try_next_time:
603 	port_map_tried = 0;
604 
605 try_next_port:
606 
607 	hcs_params = readl(&ehci_caps->hcs_params);
608 	debug_port = HCS_DEBUG_PORT(hcs_params);
609 	n_ports    = HCS_N_PORTS(hcs_params);
610 
611 	dbgp_printk("debug_port: %d\n", debug_port);
612 	dbgp_printk("n_ports:    %d\n", n_ports);
613 
614 	for (i = 1; i <= n_ports; i++) {
615 		portsc = readl(&ehci_regs->port_status[i-1]);
616 		dbgp_printk("portstatus%d: %08x\n", i, portsc);
617 	}
618 
619 	if (port_map_tried && (new_debug_port != debug_port)) {
620 		if (--playtimes) {
621 			set_debug_port(new_debug_port);
622 			goto try_next_time;
623 		}
624 		return -1;
625 	}
626 
627 	loop = 10;
628 	/* Reset the EHCI controller */
629 	cmd = readl(&ehci_regs->command);
630 	cmd |= CMD_RESET;
631 	writel(cmd, &ehci_regs->command);
632 	do {
633 		cmd = readl(&ehci_regs->command);
634 	} while ((cmd & CMD_RESET) && (--loop > 0));
635 
636 	if (!loop) {
637 		dbgp_printk("can not reset ehci\n");
638 		return -1;
639 	}
640 	dbgp_printk("ehci reset done\n");
641 
642 	/* Claim ownership, but do not enable yet */
643 	ctrl = readl(&ehci_debug->control);
644 	ctrl |= DBGP_OWNER;
645 	ctrl &= ~(DBGP_ENABLED | DBGP_INUSE);
646 	writel(ctrl, &ehci_debug->control);
647 
648 	/* Start the ehci running */
649 	cmd = readl(&ehci_regs->command);
650 	cmd &= ~(CMD_LRESET | CMD_IAAD | CMD_PSE | CMD_ASE | CMD_RESET);
651 	cmd |= CMD_RUN;
652 	writel(cmd, &ehci_regs->command);
653 
654 	/* Ensure everything is routed to the EHCI */
655 	writel(FLAG_CF, &ehci_regs->configured_flag);
656 
657 	/* Wait until the controller is no longer halted */
658 	loop = 10;
659 	do {
660 		status = readl(&ehci_regs->status);
661 	} while ((status & STS_HALT) && (--loop > 0));
662 
663 	if (!loop) {
664 		dbgp_printk("ehci can be started\n");
665 		return -1;
666 	}
667 	dbgp_printk("ehci started\n");
668 
669 	/* Wait for a device to show up in the debug port */
670 	ret = ehci_wait_for_port(debug_port);
671 	if (ret < 0) {
672 		dbgp_printk("No device found in debug port\n");
673 		goto next_debug_port;
674 	}
675 	dbgp_printk("ehci wait for port done\n");
676 
677 	/* Enable the debug port */
678 	ctrl = readl(&ehci_debug->control);
679 	ctrl |= DBGP_CLAIM;
680 	writel(ctrl, &ehci_debug->control);
681 	ctrl = readl(&ehci_debug->control);
682 	if ((ctrl & DBGP_CLAIM) != DBGP_CLAIM) {
683 		dbgp_printk("No device in debug port\n");
684 		writel(ctrl & ~DBGP_CLAIM, &ehci_debug->control);
685 		goto err;
686 	}
687 	dbgp_printk("debug ported enabled\n");
688 
689 	/* Completely transfer the debug device to the debug controller */
690 	portsc = readl(&ehci_regs->port_status[debug_port - 1]);
691 	portsc &= ~PORT_PE;
692 	writel(portsc, &ehci_regs->port_status[debug_port - 1]);
693 
694 	dbgp_mdelay(100);
695 
696 	/* Find the debug device and make it device number 127 */
697 	for (devnum = 0; devnum <= 127; devnum++) {
698 		ret = dbgp_control_msg(devnum,
699 			USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
700 			USB_REQ_GET_DESCRIPTOR, (USB_DT_DEBUG << 8), 0,
701 			&dbgp_desc, sizeof(dbgp_desc));
702 		if (ret > 0)
703 			break;
704 	}
705 	if (devnum > 127) {
706 		dbgp_printk("Could not find attached debug device\n");
707 		goto err;
708 	}
709 	if (ret < 0) {
710 		dbgp_printk("Attached device is not a debug device\n");
711 		goto err;
712 	}
713 	dbgp_endpoint_out = dbgp_desc.bDebugOutEndpoint;
714 
715 	/* Move the device to 127 if it isn't already there */
716 	if (devnum != USB_DEBUG_DEVNUM) {
717 		ret = dbgp_control_msg(devnum,
718 			USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
719 			USB_REQ_SET_ADDRESS, USB_DEBUG_DEVNUM, 0, NULL, 0);
720 		if (ret < 0) {
721 			dbgp_printk("Could not move attached device to %d\n",
722 				USB_DEBUG_DEVNUM);
723 			goto err;
724 		}
725 		devnum = USB_DEBUG_DEVNUM;
726 		dbgp_printk("debug device renamed to 127\n");
727 	}
728 
729 	/* Enable the debug interface */
730 	ret = dbgp_control_msg(USB_DEBUG_DEVNUM,
731 		USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
732 		USB_REQ_SET_FEATURE, USB_DEVICE_DEBUG_MODE, 0, NULL, 0);
733 	if (ret < 0) {
734 		dbgp_printk(" Could not enable the debug device\n");
735 		goto err;
736 	}
737 	dbgp_printk("debug interface enabled\n");
738 
739 	/* Perform a small write to get the even/odd data state in sync
740 	 */
741 	ret = dbgp_bulk_write(USB_DEBUG_DEVNUM, dbgp_endpoint_out, " ", 1);
742 	if (ret < 0) {
743 		dbgp_printk("dbgp_bulk_write failed: %d\n", ret);
744 		goto err;
745 	}
746 	dbgp_printk("small write doned\n");
747 
748 	return 0;
749 err:
750 	/* Things didn't work so remove my claim */
751 	ctrl = readl(&ehci_debug->control);
752 	ctrl &= ~(DBGP_CLAIM | DBGP_OUT);
753 	writel(ctrl, &ehci_debug->control);
754 	return -1;
755 
756 next_debug_port:
757 	port_map_tried |= (1<<(debug_port - 1));
758 	new_debug_port = ((debug_port-1+1)%n_ports) + 1;
759 	if (port_map_tried != ((1<<n_ports) - 1)) {
760 		set_debug_port(new_debug_port);
761 		goto try_next_port;
762 	}
763 	if (--playtimes) {
764 		set_debug_port(new_debug_port);
765 		goto try_next_time;
766 	}
767 
768 	return -1;
769 }
770 
771 static int __init early_dbgp_init(char *s)
772 {
773 	u32 debug_port, bar, offset;
774 	u32 bus, slot, func, cap;
775 	void __iomem *ehci_bar;
776 	u32 dbgp_num;
777 	u32 bar_val;
778 	char *e;
779 	int ret;
780 	u8 byte;
781 
782 	if (!early_pci_allowed())
783 		return -1;
784 
785 	dbgp_num = 0;
786 	if (*s)
787 		dbgp_num = simple_strtoul(s, &e, 10);
788 	dbgp_printk("dbgp_num: %d\n", dbgp_num);
789 
790 	cap = find_dbgp(dbgp_num, &bus, &slot, &func);
791 	if (!cap)
792 		return -1;
793 
794 	dbgp_printk("Found EHCI debug port on %02x:%02x.%1x\n", bus, slot,
795 			 func);
796 
797 	debug_port = read_pci_config(bus, slot, func, cap);
798 	bar = (debug_port >> 29) & 0x7;
799 	bar = (bar * 4) + 0xc;
800 	offset = (debug_port >> 16) & 0xfff;
801 	dbgp_printk("bar: %02x offset: %03x\n", bar, offset);
802 	if (bar != PCI_BASE_ADDRESS_0) {
803 		dbgp_printk("only debug ports on bar 1 handled.\n");
804 
805 		return -1;
806 	}
807 
808 	bar_val = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
809 	dbgp_printk("bar_val: %02x offset: %03x\n", bar_val, offset);
810 	if (bar_val & ~PCI_BASE_ADDRESS_MEM_MASK) {
811 		dbgp_printk("only simple 32bit mmio bars supported\n");
812 
813 		return -1;
814 	}
815 
816 	/* double check if the mem space is enabled */
817 	byte = read_pci_config_byte(bus, slot, func, 0x04);
818 	if (!(byte & 0x2)) {
819 		byte  |= 0x02;
820 		write_pci_config_byte(bus, slot, func, 0x04, byte);
821 		dbgp_printk("mmio for ehci enabled\n");
822 	}
823 
824 	/*
825 	 * FIXME I don't have the bar size so just guess PAGE_SIZE is more
826 	 * than enough.  1K is the biggest I have seen.
827 	 */
828 	set_fixmap_nocache(FIX_DBGP_BASE, bar_val & PAGE_MASK);
829 	ehci_bar = (void __iomem *)__fix_to_virt(FIX_DBGP_BASE);
830 	ehci_bar += bar_val & ~PAGE_MASK;
831 	dbgp_printk("ehci_bar: %p\n", ehci_bar);
832 
833 	ehci_caps  = ehci_bar;
834 	ehci_regs  = ehci_bar + HC_LENGTH(readl(&ehci_caps->hc_capbase));
835 	ehci_debug = ehci_bar + offset;
836 	ehci_dev.bus = bus;
837 	ehci_dev.slot = slot;
838 	ehci_dev.func = func;
839 
840 	detect_set_debug_port();
841 
842 	ret = ehci_setup();
843 	if (ret < 0) {
844 		dbgp_printk("ehci_setup failed\n");
845 		ehci_debug = NULL;
846 
847 		return -1;
848 	}
849 
850 	return 0;
851 }
852 
853 static void early_dbgp_write(struct console *con, const char *str, u32 n)
854 {
855 	int chunk, ret;
856 
857 	if (!ehci_debug)
858 		return;
859 	while (n > 0) {
860 		chunk = n;
861 		if (chunk > DBGP_MAX_PACKET)
862 			chunk = DBGP_MAX_PACKET;
863 		ret = dbgp_bulk_write(USB_DEBUG_DEVNUM,
864 			dbgp_endpoint_out, str, chunk);
865 		str += chunk;
866 		n -= chunk;
867 	}
868 }
869 
870 static struct console early_dbgp_console = {
871 	.name =		"earlydbg",
872 	.write =	early_dbgp_write,
873 	.flags =	CON_PRINTBUFFER,
874 	.index =	-1,
875 };
876 #endif
877 
878 /* Direct interface for emergencies */
879 static struct console *early_console = &early_vga_console;
880 static int __initdata early_console_initialized;
881 
882 asmlinkage void early_printk(const char *fmt, ...)
883 {
884 	char buf[512];
885 	int n;
886 	va_list ap;
887 
888 	va_start(ap, fmt);
889 	n = vscnprintf(buf, sizeof(buf), fmt, ap);
890 	early_console->write(early_console, buf, n);
891 	va_end(ap);
892 }
893 
894 
895 static int __init setup_early_printk(char *buf)
896 {
897 	int keep_early;
898 
899 	if (!buf)
900 		return 0;
901 
902 	if (early_console_initialized)
903 		return 0;
904 	early_console_initialized = 1;
905 
906 	keep_early = (strstr(buf, "keep") != NULL);
907 
908 	if (!strncmp(buf, "serial", 6)) {
909 		early_serial_init(buf + 6);
910 		early_console = &early_serial_console;
911 	} else if (!strncmp(buf, "ttyS", 4)) {
912 		early_serial_init(buf);
913 		early_console = &early_serial_console;
914 	} else if (!strncmp(buf, "vga", 3)
915 		&& boot_params.screen_info.orig_video_isVGA == 1) {
916 		max_xpos = boot_params.screen_info.orig_video_cols;
917 		max_ypos = boot_params.screen_info.orig_video_lines;
918 		current_ypos = boot_params.screen_info.orig_y;
919 		early_console = &early_vga_console;
920 #ifdef CONFIG_EARLY_PRINTK_DBGP
921 	} else if (!strncmp(buf, "dbgp", 4)) {
922 		if (early_dbgp_init(buf+4) < 0)
923 			return 0;
924 		early_console = &early_dbgp_console;
925 		/*
926 		 * usb subsys will reset ehci controller, so don't keep
927 		 * that early console
928 		 */
929 		keep_early = 0;
930 #endif
931 #ifdef CONFIG_HVC_XEN
932 	} else if (!strncmp(buf, "xen", 3)) {
933 		early_console = &xenboot_console;
934 #endif
935 	}
936 
937 	if (keep_early)
938 		early_console->flags &= ~CON_BOOT;
939 	else
940 		early_console->flags |= CON_BOOT;
941 	register_console(early_console);
942 	return 0;
943 }
944 
945 early_param("earlyprintk", setup_early_printk);
946