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