1 #include <linux/kernel.h>
2 #include <linux/serial.h>
3 #include <linux/serial_8250.h>
4 #include <linux/serial_core.h>
5 #include <linux/console.h>
6 #include <linux/pci.h>
7 #include <linux/of_device.h>
8 #include <asm/io.h>
9 #include <asm/mmu.h>
10 #include <asm/prom.h>
11 #include <asm/serial.h>
12 #include <asm/udbg.h>
13 #include <asm/pci-bridge.h>
14 #include <asm/ppc-pci.h>
15 
16 #undef DEBUG
17 
18 #ifdef DEBUG
19 #define DBG(fmt...) do { printk(fmt); } while(0)
20 #else
21 #define DBG(fmt...) do { } while(0)
22 #endif
23 
24 #define MAX_LEGACY_SERIAL_PORTS	8
25 
26 static struct plat_serial8250_port
27 legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1];
28 static struct legacy_serial_info {
29 	struct device_node		*np;
30 	unsigned int			speed;
31 	unsigned int			clock;
32 	int				irq_check_parent;
33 	phys_addr_t			taddr;
34 } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
35 
36 static struct __initdata of_device_id parents[] = {
37 	{.type = "soc",},
38 	{.type = "tsi-bridge",},
39 	{.type = "opb", },
40 	{.compatible = "ibm,opb",},
41 	{.compatible = "simple-bus",},
42 	{.compatible = "wrs,epld-localbus",},
43 };
44 
45 static unsigned int legacy_serial_count;
46 static int legacy_serial_console = -1;
47 
48 static int __init add_legacy_port(struct device_node *np, int want_index,
49 				  int iotype, phys_addr_t base,
50 				  phys_addr_t taddr, unsigned long irq,
51 				  upf_t flags, int irq_check_parent)
52 {
53 	const u32 *clk, *spd;
54 	u32 clock = BASE_BAUD * 16;
55 	int index;
56 
57 	/* get clock freq. if present */
58 	clk = of_get_property(np, "clock-frequency", NULL);
59 	if (clk && *clk)
60 		clock = *clk;
61 
62 	/* get default speed if present */
63 	spd = of_get_property(np, "current-speed", NULL);
64 
65 	/* If we have a location index, then try to use it */
66 	if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS)
67 		index = want_index;
68 	else
69 		index = legacy_serial_count;
70 
71 	/* if our index is still out of range, that mean that
72 	 * array is full, we could scan for a free slot but that
73 	 * make little sense to bother, just skip the port
74 	 */
75 	if (index >= MAX_LEGACY_SERIAL_PORTS)
76 		return -1;
77 	if (index >= legacy_serial_count)
78 		legacy_serial_count = index + 1;
79 
80 	/* Check if there is a port who already claimed our slot */
81 	if (legacy_serial_infos[index].np != 0) {
82 		/* if we still have some room, move it, else override */
83 		if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
84 			printk(KERN_DEBUG "Moved legacy port %d -> %d\n",
85 			       index, legacy_serial_count);
86 			legacy_serial_ports[legacy_serial_count] =
87 				legacy_serial_ports[index];
88 			legacy_serial_infos[legacy_serial_count] =
89 				legacy_serial_infos[index];
90 			legacy_serial_count++;
91 		} else {
92 			printk(KERN_DEBUG "Replacing legacy port %d\n", index);
93 		}
94 	}
95 
96 	/* Now fill the entry */
97 	memset(&legacy_serial_ports[index], 0,
98 	       sizeof(struct plat_serial8250_port));
99 	if (iotype == UPIO_PORT)
100 		legacy_serial_ports[index].iobase = base;
101 	else
102 		legacy_serial_ports[index].mapbase = base;
103 	legacy_serial_ports[index].iotype = iotype;
104 	legacy_serial_ports[index].uartclk = clock;
105 	legacy_serial_ports[index].irq = irq;
106 	legacy_serial_ports[index].flags = flags;
107 	legacy_serial_infos[index].taddr = taddr;
108 	legacy_serial_infos[index].np = of_node_get(np);
109 	legacy_serial_infos[index].clock = clock;
110 	legacy_serial_infos[index].speed = spd ? *spd : 0;
111 	legacy_serial_infos[index].irq_check_parent = irq_check_parent;
112 
113 	printk(KERN_DEBUG "Found legacy serial port %d for %s\n",
114 	       index, np->full_name);
115 	printk(KERN_DEBUG "  %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
116 	       (iotype == UPIO_PORT) ? "port" : "mem",
117 	       (unsigned long long)base, (unsigned long long)taddr, irq,
118 	       legacy_serial_ports[index].uartclk,
119 	       legacy_serial_infos[index].speed);
120 
121 	return index;
122 }
123 
124 static int __init add_legacy_soc_port(struct device_node *np,
125 				      struct device_node *soc_dev)
126 {
127 	u64 addr;
128 	const u32 *addrp;
129 	upf_t flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ
130 		| UPF_FIXED_PORT;
131 	struct device_node *tsi = of_get_parent(np);
132 
133 	/* We only support ports that have a clock frequency properly
134 	 * encoded in the device-tree.
135 	 */
136 	if (of_get_property(np, "clock-frequency", NULL) == NULL)
137 		return -1;
138 
139 	/* if rtas uses this device, don't try to use it as well */
140 	if (of_get_property(np, "used-by-rtas", NULL) != NULL)
141 		return -1;
142 
143 	/* Get the address */
144 	addrp = of_get_address(soc_dev, 0, NULL, NULL);
145 	if (addrp == NULL)
146 		return -1;
147 
148 	addr = of_translate_address(soc_dev, addrp);
149 	if (addr == OF_BAD_ADDR)
150 		return -1;
151 
152 	/* Add port, irq will be dealt with later. We passed a translated
153 	 * IO port value. It will be fixed up later along with the irq
154 	 */
155 	if (tsi && !strcmp(tsi->type, "tsi-bridge"))
156 		return add_legacy_port(np, -1, UPIO_TSI, addr, addr, NO_IRQ, flags, 0);
157 	else
158 		return add_legacy_port(np, -1, UPIO_MEM, addr, addr, NO_IRQ, flags, 0);
159 }
160 
161 static int __init add_legacy_isa_port(struct device_node *np,
162 				      struct device_node *isa_brg)
163 {
164 	const u32 *reg;
165 	const char *typep;
166 	int index = -1;
167 	u64 taddr;
168 
169 	DBG(" -> add_legacy_isa_port(%s)\n", np->full_name);
170 
171 	/* Get the ISA port number */
172 	reg = of_get_property(np, "reg", NULL);
173 	if (reg == NULL)
174 		return -1;
175 
176 	/* Verify it's an IO port, we don't support anything else */
177 	if (!(reg[0] & 0x00000001))
178 		return -1;
179 
180 	/* Now look for an "ibm,aix-loc" property that gives us ordering
181 	 * if any...
182 	 */
183 	typep = of_get_property(np, "ibm,aix-loc", NULL);
184 
185 	/* If we have a location index, then use it */
186 	if (typep && *typep == 'S')
187 		index = simple_strtol(typep+1, NULL, 0) - 1;
188 
189 	/* Translate ISA address. If it fails, we still register the port
190 	 * with no translated address so that it can be picked up as an IO
191 	 * port later by the serial driver
192 	 */
193 	taddr = of_translate_address(np, reg);
194 	if (taddr == OF_BAD_ADDR)
195 		taddr = 0;
196 
197 	/* Add port, irq will be dealt with later */
198 	return add_legacy_port(np, index, UPIO_PORT, reg[1], taddr,
199 			       NO_IRQ, UPF_BOOT_AUTOCONF, 0);
200 
201 }
202 
203 #ifdef CONFIG_PCI
204 static int __init add_legacy_pci_port(struct device_node *np,
205 				      struct device_node *pci_dev)
206 {
207 	u64 addr, base;
208 	const u32 *addrp;
209 	unsigned int flags;
210 	int iotype, index = -1, lindex = 0;
211 
212 	DBG(" -> add_legacy_pci_port(%s)\n", np->full_name);
213 
214 	/* We only support ports that have a clock frequency properly
215 	 * encoded in the device-tree (that is have an fcode). Anything
216 	 * else can't be used that early and will be normally probed by
217 	 * the generic 8250_pci driver later on. The reason is that 8250
218 	 * compatible UARTs on PCI need all sort of quirks (port offsets
219 	 * etc...) that this code doesn't know about
220 	 */
221 	if (of_get_property(np, "clock-frequency", NULL) == NULL)
222 		return -1;
223 
224 	/* Get the PCI address. Assume BAR 0 */
225 	addrp = of_get_pci_address(pci_dev, 0, NULL, &flags);
226 	if (addrp == NULL)
227 		return -1;
228 
229 	/* We only support BAR 0 for now */
230 	iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT;
231 	addr = of_translate_address(pci_dev, addrp);
232 	if (addr == OF_BAD_ADDR)
233 		return -1;
234 
235 	/* Set the IO base to the same as the translated address for MMIO,
236 	 * or to the domain local IO base for PIO (it will be fixed up later)
237 	 */
238 	if (iotype == UPIO_MEM)
239 		base = addr;
240 	else
241 		base = addrp[2];
242 
243 	/* Try to guess an index... If we have subdevices of the pci dev,
244 	 * we get to their "reg" property
245 	 */
246 	if (np != pci_dev) {
247 		const u32 *reg = of_get_property(np, "reg", NULL);
248 		if (reg && (*reg < 4))
249 			index = lindex = *reg;
250 	}
251 
252 	/* Local index means it's the Nth port in the PCI chip. Unfortunately
253 	 * the offset to add here is device specific. We know about those
254 	 * EXAR ports and we default to the most common case. If your UART
255 	 * doesn't work for these settings, you'll have to add your own special
256 	 * cases here
257 	 */
258 	if (of_device_is_compatible(pci_dev, "pci13a8,152") ||
259 	    of_device_is_compatible(pci_dev, "pci13a8,154") ||
260 	    of_device_is_compatible(pci_dev, "pci13a8,158")) {
261 		addr += 0x200 * lindex;
262 		base += 0x200 * lindex;
263 	} else {
264 		addr += 8 * lindex;
265 		base += 8 * lindex;
266 	}
267 
268 	/* Add port, irq will be dealt with later. We passed a translated
269 	 * IO port value. It will be fixed up later along with the irq
270 	 */
271 	return add_legacy_port(np, index, iotype, base, addr, NO_IRQ,
272 			       UPF_BOOT_AUTOCONF, np != pci_dev);
273 }
274 #endif
275 
276 static void __init setup_legacy_serial_console(int console)
277 {
278 	struct legacy_serial_info *info =
279 		&legacy_serial_infos[console];
280 	void __iomem *addr;
281 
282 	if (info->taddr == 0)
283 		return;
284 	addr = ioremap(info->taddr, 0x1000);
285 	if (addr == NULL)
286 		return;
287 	if (info->speed == 0)
288 		info->speed = udbg_probe_uart_speed(addr, info->clock);
289 	DBG("default console speed = %d\n", info->speed);
290 	udbg_init_uart(addr, info->speed, info->clock);
291 }
292 
293 /*
294  * This is called very early, as part of setup_system() or eventually
295  * setup_arch(), basically before anything else in this file. This function
296  * will try to build a list of all the available 8250-compatible serial ports
297  * in the machine using the Open Firmware device-tree. It currently only deals
298  * with ISA and PCI busses but could be extended. It allows a very early boot
299  * console to be initialized, that list is also used later to provide 8250 with
300  * the machine non-PCI ports and to properly pick the default console port
301  */
302 void __init find_legacy_serial_ports(void)
303 {
304 	struct device_node *np, *stdout = NULL;
305 	const char *path;
306 	int index;
307 
308 	DBG(" -> find_legacy_serial_port()\n");
309 
310 	/* Now find out if one of these is out firmware console */
311 	path = of_get_property(of_chosen, "linux,stdout-path", NULL);
312 	if (path != NULL) {
313 		stdout = of_find_node_by_path(path);
314 		if (stdout)
315 			DBG("stdout is %s\n", stdout->full_name);
316 	} else {
317 		DBG(" no linux,stdout-path !\n");
318 	}
319 
320 	/* Iterate over all the 16550 ports, looking for known parents */
321 	for_each_compatible_node(np, "serial", "ns16550") {
322 		struct device_node *parent = of_get_parent(np);
323 		if (!parent)
324 			continue;
325 		if (of_match_node(parents, parent) != NULL) {
326 			index = add_legacy_soc_port(np, np);
327 			if (index >= 0 && np == stdout)
328 				legacy_serial_console = index;
329 		}
330 		of_node_put(parent);
331 	}
332 
333 	/* Next, fill our array with ISA ports */
334 	for_each_node_by_type(np, "serial") {
335 		struct device_node *isa = of_get_parent(np);
336 		if (isa && !strcmp(isa->name, "isa")) {
337 			index = add_legacy_isa_port(np, isa);
338 			if (index >= 0 && np == stdout)
339 				legacy_serial_console = index;
340 		}
341 		of_node_put(isa);
342 	}
343 
344 #ifdef CONFIG_PCI
345 	/* Next, try to locate PCI ports */
346 	for (np = NULL; (np = of_find_all_nodes(np));) {
347 		struct device_node *pci, *parent = of_get_parent(np);
348 		if (parent && !strcmp(parent->name, "isa")) {
349 			of_node_put(parent);
350 			continue;
351 		}
352 		if (strcmp(np->name, "serial") && strcmp(np->type, "serial")) {
353 			of_node_put(parent);
354 			continue;
355 		}
356 		/* Check for known pciclass, and also check wether we have
357 		 * a device with child nodes for ports or not
358 		 */
359 		if (of_device_is_compatible(np, "pciclass,0700") ||
360 		    of_device_is_compatible(np, "pciclass,070002"))
361 			pci = np;
362 		else if (of_device_is_compatible(parent, "pciclass,0700") ||
363 			 of_device_is_compatible(parent, "pciclass,070002"))
364 			pci = parent;
365 		else {
366 			of_node_put(parent);
367 			continue;
368 		}
369 		index = add_legacy_pci_port(np, pci);
370 		if (index >= 0 && np == stdout)
371 			legacy_serial_console = index;
372 		of_node_put(parent);
373 	}
374 #endif
375 
376 	DBG("legacy_serial_console = %d\n", legacy_serial_console);
377 	if (legacy_serial_console >= 0)
378 		setup_legacy_serial_console(legacy_serial_console);
379 	DBG(" <- find_legacy_serial_port()\n");
380 }
381 
382 static struct platform_device serial_device = {
383 	.name	= "serial8250",
384 	.id	= PLAT8250_DEV_PLATFORM,
385 	.dev	= {
386 		.platform_data = legacy_serial_ports,
387 	},
388 };
389 
390 static void __init fixup_port_irq(int index,
391 				  struct device_node *np,
392 				  struct plat_serial8250_port *port)
393 {
394 	unsigned int virq;
395 
396 	DBG("fixup_port_irq(%d)\n", index);
397 
398 	virq = irq_of_parse_and_map(np, 0);
399 	if (virq == NO_IRQ && legacy_serial_infos[index].irq_check_parent) {
400 		np = of_get_parent(np);
401 		if (np == NULL)
402 			return;
403 		virq = irq_of_parse_and_map(np, 0);
404 		of_node_put(np);
405 	}
406 	if (virq == NO_IRQ)
407 		return;
408 
409 	port->irq = virq;
410 }
411 
412 static void __init fixup_port_pio(int index,
413 				  struct device_node *np,
414 				  struct plat_serial8250_port *port)
415 {
416 #ifdef CONFIG_PCI
417 	struct pci_controller *hose;
418 
419 	DBG("fixup_port_pio(%d)\n", index);
420 
421 	hose = pci_find_hose_for_OF_device(np);
422 	if (hose) {
423 		unsigned long offset = (unsigned long)hose->io_base_virt -
424 #ifdef CONFIG_PPC64
425 			pci_io_base;
426 #else
427 			isa_io_base;
428 #endif
429 		DBG("port %d, IO %lx -> %lx\n",
430 		    index, port->iobase, port->iobase + offset);
431 		port->iobase += offset;
432 	}
433 #endif
434 }
435 
436 static void __init fixup_port_mmio(int index,
437 				   struct device_node *np,
438 				   struct plat_serial8250_port *port)
439 {
440 	DBG("fixup_port_mmio(%d)\n", index);
441 
442 	port->membase = ioremap(port->mapbase, 0x100);
443 }
444 
445 /*
446  * This is called as an arch initcall, hopefully before the PCI bus is
447  * probed and/or the 8250 driver loaded since we need to register our
448  * platform devices before 8250 PCI ones are detected as some of them
449  * must properly "override" the platform ones.
450  *
451  * This function fixes up the interrupt value for platform ports as it
452  * couldn't be done earlier before interrupt maps have been parsed. It
453  * also "corrects" the IO address for PIO ports for the same reason,
454  * since earlier, the PHBs virtual IO space wasn't assigned yet. It then
455  * registers all those platform ports for use by the 8250 driver when it
456  * finally loads.
457  */
458 static int __init serial_dev_init(void)
459 {
460 	int i;
461 
462 	if (legacy_serial_count == 0)
463 		return -ENODEV;
464 
465 	/*
466 	 * Before we register the platfrom serial devices, we need
467 	 * to fixup their interrupts and their IO ports.
468 	 */
469 	DBG("Fixing serial ports interrupts and IO ports ...\n");
470 
471 	for (i = 0; i < legacy_serial_count; i++) {
472 		struct plat_serial8250_port *port = &legacy_serial_ports[i];
473 		struct device_node *np = legacy_serial_infos[i].np;
474 
475 		if (port->irq == NO_IRQ)
476 			fixup_port_irq(i, np, port);
477 		if (port->iotype == UPIO_PORT)
478 			fixup_port_pio(i, np, port);
479 		if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI))
480 			fixup_port_mmio(i, np, port);
481 	}
482 
483 	DBG("Registering platform serial ports\n");
484 
485 	return platform_device_register(&serial_device);
486 }
487 device_initcall(serial_dev_init);
488 
489 
490 /*
491  * This is called very early, as part of console_init() (typically just after
492  * time_init()). This function is respondible for trying to find a good
493  * default console on serial ports. It tries to match the open firmware
494  * default output with one of the available serial console drivers, either
495  * one of the platform serial ports that have been probed earlier by
496  * find_legacy_serial_ports() or some more platform specific ones.
497  */
498 static int __init check_legacy_serial_console(void)
499 {
500 	struct device_node *prom_stdout = NULL;
501 	int speed = 0, offset = 0;
502 	const char *name;
503 	const u32 *spd;
504 
505 	DBG(" -> check_legacy_serial_console()\n");
506 
507 	/* The user has requested a console so this is already set up. */
508 	if (strstr(boot_command_line, "console=")) {
509 		DBG(" console was specified !\n");
510 		return -EBUSY;
511 	}
512 
513 	if (!of_chosen) {
514 		DBG(" of_chosen is NULL !\n");
515 		return -ENODEV;
516 	}
517 
518 	if (legacy_serial_console < 0) {
519 		DBG(" legacy_serial_console not found !\n");
520 		return -ENODEV;
521 	}
522 	/* We are getting a weird phandle from OF ... */
523 	/* ... So use the full path instead */
524 	name = of_get_property(of_chosen, "linux,stdout-path", NULL);
525 	if (name == NULL) {
526 		DBG(" no linux,stdout-path !\n");
527 		return -ENODEV;
528 	}
529 	prom_stdout = of_find_node_by_path(name);
530 	if (!prom_stdout) {
531 		DBG(" can't find stdout package %s !\n", name);
532 		return -ENODEV;
533 	}
534 	DBG("stdout is %s\n", prom_stdout->full_name);
535 
536 	name = of_get_property(prom_stdout, "name", NULL);
537 	if (!name) {
538 		DBG(" stdout package has no name !\n");
539 		goto not_found;
540 	}
541 	spd = of_get_property(prom_stdout, "current-speed", NULL);
542 	if (spd)
543 		speed = *spd;
544 
545 	if (0)
546 		;
547 #ifdef CONFIG_SERIAL_8250_CONSOLE
548 	else if (strcmp(name, "serial") == 0) {
549 		int i;
550 		/* Look for it in probed array */
551 		for (i = 0; i < legacy_serial_count; i++) {
552 			if (prom_stdout != legacy_serial_infos[i].np)
553 				continue;
554 			offset = i;
555 			speed = legacy_serial_infos[i].speed;
556 			break;
557 		}
558 		if (i >= legacy_serial_count)
559 			goto not_found;
560 	}
561 #endif /* CONFIG_SERIAL_8250_CONSOLE */
562 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
563 	else if (strcmp(name, "ch-a") == 0)
564 		offset = 0;
565 	else if (strcmp(name, "ch-b") == 0)
566 		offset = 1;
567 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
568 	else
569 		goto not_found;
570 	of_node_put(prom_stdout);
571 
572 	DBG("Found serial console at ttyS%d\n", offset);
573 
574 	if (speed) {
575 		static char __initdata opt[16];
576 		sprintf(opt, "%d", speed);
577 		return add_preferred_console("ttyS", offset, opt);
578 	} else
579 		return add_preferred_console("ttyS", offset, NULL);
580 
581  not_found:
582 	DBG("No preferred console found !\n");
583 	of_node_put(prom_stdout);
584 	return -ENODEV;
585 }
586 console_initcall(check_legacy_serial_console);
587 
588