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_address.h>
8 #include <linux/of_device.h>
9 #include <linux/serial_reg.h>
10 #include <asm/io.h>
11 #include <asm/mmu.h>
12 #include <asm/prom.h>
13 #include <asm/serial.h>
14 #include <asm/udbg.h>
15 #include <asm/pci-bridge.h>
16 #include <asm/ppc-pci.h>
17 
18 #undef DEBUG
19 
20 #ifdef DEBUG
21 #define DBG(fmt...) do { printk(fmt); } while(0)
22 #else
23 #define DBG(fmt...) do { } while(0)
24 #endif
25 
26 #define MAX_LEGACY_SERIAL_PORTS	8
27 
28 static struct plat_serial8250_port
29 legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1];
30 static struct legacy_serial_info {
31 	struct device_node		*np;
32 	unsigned int			speed;
33 	unsigned int			clock;
34 	int				irq_check_parent;
35 	phys_addr_t			taddr;
36 } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
37 
38 static struct of_device_id legacy_serial_parents[] __initdata = {
39 	{.type = "soc",},
40 	{.type = "tsi-bridge",},
41 	{.type = "opb", },
42 	{.compatible = "ibm,opb",},
43 	{.compatible = "simple-bus",},
44 	{.compatible = "wrs,epld-localbus",},
45 	{},
46 };
47 
48 static unsigned int legacy_serial_count;
49 static int legacy_serial_console = -1;
50 
51 static unsigned int tsi_serial_in(struct uart_port *p, int offset)
52 {
53 	unsigned int tmp;
54 	offset = offset << p->regshift;
55 	if (offset == UART_IIR) {
56 		tmp = readl(p->membase + (UART_IIR & ~3));
57 		return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
58 	} else
59 		return readb(p->membase + offset);
60 }
61 
62 static void tsi_serial_out(struct uart_port *p, int offset, int value)
63 {
64 	offset = offset << p->regshift;
65 	if (!((offset == UART_IER) && (value & UART_IER_UUE)))
66 		writeb(value, p->membase + offset);
67 }
68 
69 static int __init add_legacy_port(struct device_node *np, int want_index,
70 				  int iotype, phys_addr_t base,
71 				  phys_addr_t taddr, unsigned long irq,
72 				  upf_t flags, int irq_check_parent)
73 {
74 	const __be32 *clk, *spd;
75 	u32 clock = BASE_BAUD * 16;
76 	int index;
77 
78 	/* get clock freq. if present */
79 	clk = of_get_property(np, "clock-frequency", NULL);
80 	if (clk && *clk)
81 		clock = be32_to_cpup(clk);
82 
83 	/* get default speed if present */
84 	spd = of_get_property(np, "current-speed", NULL);
85 
86 	/* If we have a location index, then try to use it */
87 	if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS)
88 		index = want_index;
89 	else
90 		index = legacy_serial_count;
91 
92 	/* if our index is still out of range, that mean that
93 	 * array is full, we could scan for a free slot but that
94 	 * make little sense to bother, just skip the port
95 	 */
96 	if (index >= MAX_LEGACY_SERIAL_PORTS)
97 		return -1;
98 	if (index >= legacy_serial_count)
99 		legacy_serial_count = index + 1;
100 
101 	/* Check if there is a port who already claimed our slot */
102 	if (legacy_serial_infos[index].np != NULL) {
103 		/* if we still have some room, move it, else override */
104 		if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
105 			printk(KERN_DEBUG "Moved legacy port %d -> %d\n",
106 			       index, legacy_serial_count);
107 			legacy_serial_ports[legacy_serial_count] =
108 				legacy_serial_ports[index];
109 			legacy_serial_infos[legacy_serial_count] =
110 				legacy_serial_infos[index];
111 			legacy_serial_count++;
112 		} else {
113 			printk(KERN_DEBUG "Replacing legacy port %d\n", index);
114 		}
115 	}
116 
117 	/* Now fill the entry */
118 	memset(&legacy_serial_ports[index], 0,
119 	       sizeof(struct plat_serial8250_port));
120 	if (iotype == UPIO_PORT)
121 		legacy_serial_ports[index].iobase = base;
122 	else
123 		legacy_serial_ports[index].mapbase = base;
124 
125 	legacy_serial_ports[index].iotype = iotype;
126 	legacy_serial_ports[index].uartclk = clock;
127 	legacy_serial_ports[index].irq = irq;
128 	legacy_serial_ports[index].flags = flags;
129 	legacy_serial_infos[index].taddr = taddr;
130 	legacy_serial_infos[index].np = of_node_get(np);
131 	legacy_serial_infos[index].clock = clock;
132 	legacy_serial_infos[index].speed = spd ? be32_to_cpup(spd) : 0;
133 	legacy_serial_infos[index].irq_check_parent = irq_check_parent;
134 
135 	if (iotype == UPIO_TSI) {
136 		legacy_serial_ports[index].serial_in = tsi_serial_in;
137 		legacy_serial_ports[index].serial_out = tsi_serial_out;
138 	}
139 
140 	printk(KERN_DEBUG "Found legacy serial port %d for %s\n",
141 	       index, np->full_name);
142 	printk(KERN_DEBUG "  %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
143 	       (iotype == UPIO_PORT) ? "port" : "mem",
144 	       (unsigned long long)base, (unsigned long long)taddr, irq,
145 	       legacy_serial_ports[index].uartclk,
146 	       legacy_serial_infos[index].speed);
147 
148 	return index;
149 }
150 
151 static int __init add_legacy_soc_port(struct device_node *np,
152 				      struct device_node *soc_dev)
153 {
154 	u64 addr;
155 	const __be32 *addrp;
156 	upf_t flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ
157 		| UPF_FIXED_PORT;
158 	struct device_node *tsi = of_get_parent(np);
159 
160 	/* We only support ports that have a clock frequency properly
161 	 * encoded in the device-tree.
162 	 */
163 	if (of_get_property(np, "clock-frequency", NULL) == NULL)
164 		return -1;
165 
166 	/* if reg-shift or offset, don't try to use it */
167 	if ((of_get_property(np, "reg-shift", NULL) != NULL) ||
168 		(of_get_property(np, "reg-offset", NULL) != NULL))
169 		return -1;
170 
171 	/* if rtas uses this device, don't try to use it as well */
172 	if (of_get_property(np, "used-by-rtas", NULL) != NULL)
173 		return -1;
174 
175 	/* Get the address */
176 	addrp = of_get_address(soc_dev, 0, NULL, NULL);
177 	if (addrp == NULL)
178 		return -1;
179 
180 	addr = of_translate_address(soc_dev, addrp);
181 	if (addr == OF_BAD_ADDR)
182 		return -1;
183 
184 	/* Add port, irq will be dealt with later. We passed a translated
185 	 * IO port value. It will be fixed up later along with the irq
186 	 */
187 	if (tsi && !strcmp(tsi->type, "tsi-bridge"))
188 		return add_legacy_port(np, -1, UPIO_TSI, addr, addr, NO_IRQ, flags, 0);
189 	else
190 		return add_legacy_port(np, -1, UPIO_MEM, addr, addr, NO_IRQ, flags, 0);
191 }
192 
193 static int __init add_legacy_isa_port(struct device_node *np,
194 				      struct device_node *isa_brg)
195 {
196 	const __be32 *reg;
197 	const char *typep;
198 	int index = -1;
199 	u64 taddr;
200 
201 	DBG(" -> add_legacy_isa_port(%s)\n", np->full_name);
202 
203 	/* Get the ISA port number */
204 	reg = of_get_property(np, "reg", NULL);
205 	if (reg == NULL)
206 		return -1;
207 
208 	/* Verify it's an IO port, we don't support anything else */
209 	if (!(be32_to_cpu(reg[0]) & 0x00000001))
210 		return -1;
211 
212 	/* Now look for an "ibm,aix-loc" property that gives us ordering
213 	 * if any...
214 	 */
215 	typep = of_get_property(np, "ibm,aix-loc", NULL);
216 
217 	/* If we have a location index, then use it */
218 	if (typep && *typep == 'S')
219 		index = simple_strtol(typep+1, NULL, 0) - 1;
220 
221 	/* Translate ISA address. If it fails, we still register the port
222 	 * with no translated address so that it can be picked up as an IO
223 	 * port later by the serial driver
224 	 *
225 	 * Note: Don't even try on P8 lpc, we know it's not directly mapped
226 	 */
227 	if (!of_device_is_compatible(isa_brg, "ibm,power8-lpc")) {
228 		taddr = of_translate_address(np, reg);
229 		if (taddr == OF_BAD_ADDR)
230 			taddr = 0;
231 	} else
232 		taddr = 0;
233 
234 	/* Add port, irq will be dealt with later */
235 	return add_legacy_port(np, index, UPIO_PORT, be32_to_cpu(reg[1]),
236 			       taddr, NO_IRQ, UPF_BOOT_AUTOCONF, 0);
237 
238 }
239 
240 #ifdef CONFIG_PCI
241 static int __init add_legacy_pci_port(struct device_node *np,
242 				      struct device_node *pci_dev)
243 {
244 	u64 addr, base;
245 	const __be32 *addrp;
246 	unsigned int flags;
247 	int iotype, index = -1, lindex = 0;
248 
249 	DBG(" -> add_legacy_pci_port(%s)\n", np->full_name);
250 
251 	/* We only support ports that have a clock frequency properly
252 	 * encoded in the device-tree (that is have an fcode). Anything
253 	 * else can't be used that early and will be normally probed by
254 	 * the generic 8250_pci driver later on. The reason is that 8250
255 	 * compatible UARTs on PCI need all sort of quirks (port offsets
256 	 * etc...) that this code doesn't know about
257 	 */
258 	if (of_get_property(np, "clock-frequency", NULL) == NULL)
259 		return -1;
260 
261 	/* Get the PCI address. Assume BAR 0 */
262 	addrp = of_get_pci_address(pci_dev, 0, NULL, &flags);
263 	if (addrp == NULL)
264 		return -1;
265 
266 	/* We only support BAR 0 for now */
267 	iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT;
268 	addr = of_translate_address(pci_dev, addrp);
269 	if (addr == OF_BAD_ADDR)
270 		return -1;
271 
272 	/* Set the IO base to the same as the translated address for MMIO,
273 	 * or to the domain local IO base for PIO (it will be fixed up later)
274 	 */
275 	if (iotype == UPIO_MEM)
276 		base = addr;
277 	else
278 		base = of_read_number(&addrp[2], 1);
279 
280 	/* Try to guess an index... If we have subdevices of the pci dev,
281 	 * we get to their "reg" property
282 	 */
283 	if (np != pci_dev) {
284 		const __be32 *reg = of_get_property(np, "reg", NULL);
285 		if (reg && (be32_to_cpup(reg) < 4))
286 			index = lindex = be32_to_cpup(reg);
287 	}
288 
289 	/* Local index means it's the Nth port in the PCI chip. Unfortunately
290 	 * the offset to add here is device specific. We know about those
291 	 * EXAR ports and we default to the most common case. If your UART
292 	 * doesn't work for these settings, you'll have to add your own special
293 	 * cases here
294 	 */
295 	if (of_device_is_compatible(pci_dev, "pci13a8,152") ||
296 	    of_device_is_compatible(pci_dev, "pci13a8,154") ||
297 	    of_device_is_compatible(pci_dev, "pci13a8,158")) {
298 		addr += 0x200 * lindex;
299 		base += 0x200 * lindex;
300 	} else {
301 		addr += 8 * lindex;
302 		base += 8 * lindex;
303 	}
304 
305 	/* Add port, irq will be dealt with later. We passed a translated
306 	 * IO port value. It will be fixed up later along with the irq
307 	 */
308 	return add_legacy_port(np, index, iotype, base, addr, NO_IRQ,
309 			       UPF_BOOT_AUTOCONF, np != pci_dev);
310 }
311 #endif
312 
313 static void __init setup_legacy_serial_console(int console)
314 {
315 	struct legacy_serial_info *info = &legacy_serial_infos[console];
316 	struct plat_serial8250_port *port = &legacy_serial_ports[console];
317 	void __iomem *addr;
318 
319 	/* Check if a translated MMIO address has been found */
320 	if (info->taddr) {
321 		addr = ioremap(info->taddr, 0x1000);
322 		if (addr == NULL)
323 			return;
324 		udbg_uart_init_mmio(addr, 1);
325 	} else {
326 		/* Check if it's PIO and we support untranslated PIO */
327 		if (port->iotype == UPIO_PORT && isa_io_special)
328 			udbg_uart_init_pio(port->iobase, 1);
329 		else
330 			return;
331 	}
332 
333 	/* Try to query the current speed */
334 	if (info->speed == 0)
335 		info->speed = udbg_probe_uart_speed(info->clock);
336 
337 	/* Set it up */
338 	DBG("default console speed = %d\n", info->speed);
339 	udbg_uart_setup(info->speed, info->clock);
340 }
341 
342 /*
343  * This is called very early, as part of setup_system() or eventually
344  * setup_arch(), basically before anything else in this file. This function
345  * will try to build a list of all the available 8250-compatible serial ports
346  * in the machine using the Open Firmware device-tree. It currently only deals
347  * with ISA and PCI busses but could be extended. It allows a very early boot
348  * console to be initialized, that list is also used later to provide 8250 with
349  * the machine non-PCI ports and to properly pick the default console port
350  */
351 void __init find_legacy_serial_ports(void)
352 {
353 	struct device_node *np, *stdout = NULL;
354 	const char *path;
355 	int index;
356 
357 	DBG(" -> find_legacy_serial_port()\n");
358 
359 	/* Now find out if one of these is out firmware console */
360 	path = of_get_property(of_chosen, "linux,stdout-path", NULL);
361 	if (path != NULL) {
362 		stdout = of_find_node_by_path(path);
363 		if (stdout)
364 			DBG("stdout is %s\n", stdout->full_name);
365 	} else {
366 		DBG(" no linux,stdout-path !\n");
367 	}
368 
369 	/* Iterate over all the 16550 ports, looking for known parents */
370 	for_each_compatible_node(np, "serial", "ns16550") {
371 		struct device_node *parent = of_get_parent(np);
372 		if (!parent)
373 			continue;
374 		if (of_match_node(legacy_serial_parents, parent) != NULL) {
375 			if (of_device_is_available(np)) {
376 				index = add_legacy_soc_port(np, np);
377 				if (index >= 0 && np == stdout)
378 					legacy_serial_console = index;
379 			}
380 		}
381 		of_node_put(parent);
382 	}
383 
384 	/* Next, fill our array with ISA ports */
385 	for_each_node_by_type(np, "serial") {
386 		struct device_node *isa = of_get_parent(np);
387 		if (isa && (!strcmp(isa->name, "isa") ||
388 			    !strcmp(isa->name, "lpc"))) {
389 			if (of_device_is_available(np)) {
390 				index = add_legacy_isa_port(np, isa);
391 				if (index >= 0 && np == stdout)
392 					legacy_serial_console = index;
393 			}
394 		}
395 		of_node_put(isa);
396 	}
397 
398 #ifdef CONFIG_PCI
399 	/* Next, try to locate PCI ports */
400 	for (np = NULL; (np = of_find_all_nodes(np));) {
401 		struct device_node *pci, *parent = of_get_parent(np);
402 		if (parent && !strcmp(parent->name, "isa")) {
403 			of_node_put(parent);
404 			continue;
405 		}
406 		if (strcmp(np->name, "serial") && strcmp(np->type, "serial")) {
407 			of_node_put(parent);
408 			continue;
409 		}
410 		/* Check for known pciclass, and also check whether we have
411 		 * a device with child nodes for ports or not
412 		 */
413 		if (of_device_is_compatible(np, "pciclass,0700") ||
414 		    of_device_is_compatible(np, "pciclass,070002"))
415 			pci = np;
416 		else if (of_device_is_compatible(parent, "pciclass,0700") ||
417 			 of_device_is_compatible(parent, "pciclass,070002"))
418 			pci = parent;
419 		else {
420 			of_node_put(parent);
421 			continue;
422 		}
423 		index = add_legacy_pci_port(np, pci);
424 		if (index >= 0 && np == stdout)
425 			legacy_serial_console = index;
426 		of_node_put(parent);
427 	}
428 #endif
429 
430 	DBG("legacy_serial_console = %d\n", legacy_serial_console);
431 	if (legacy_serial_console >= 0)
432 		setup_legacy_serial_console(legacy_serial_console);
433 	DBG(" <- find_legacy_serial_port()\n");
434 }
435 
436 static struct platform_device serial_device = {
437 	.name	= "serial8250",
438 	.id	= PLAT8250_DEV_PLATFORM,
439 	.dev	= {
440 		.platform_data = legacy_serial_ports,
441 	},
442 };
443 
444 static void __init fixup_port_irq(int index,
445 				  struct device_node *np,
446 				  struct plat_serial8250_port *port)
447 {
448 	unsigned int virq;
449 
450 	DBG("fixup_port_irq(%d)\n", index);
451 
452 	virq = irq_of_parse_and_map(np, 0);
453 	if (virq == NO_IRQ && legacy_serial_infos[index].irq_check_parent) {
454 		np = of_get_parent(np);
455 		if (np == NULL)
456 			return;
457 		virq = irq_of_parse_and_map(np, 0);
458 		of_node_put(np);
459 	}
460 	if (virq == NO_IRQ)
461 		return;
462 
463 	port->irq = virq;
464 
465 #ifdef CONFIG_SERIAL_8250_FSL
466 	if (of_device_is_compatible(np, "fsl,ns16550"))
467 		port->handle_irq = fsl8250_handle_irq;
468 #endif
469 }
470 
471 static void __init fixup_port_pio(int index,
472 				  struct device_node *np,
473 				  struct plat_serial8250_port *port)
474 {
475 #ifdef CONFIG_PCI
476 	struct pci_controller *hose;
477 
478 	DBG("fixup_port_pio(%d)\n", index);
479 
480 	hose = pci_find_hose_for_OF_device(np);
481 	if (hose) {
482 		unsigned long offset = (unsigned long)hose->io_base_virt -
483 #ifdef CONFIG_PPC64
484 			pci_io_base;
485 #else
486 			isa_io_base;
487 #endif
488 		DBG("port %d, IO %lx -> %lx\n",
489 		    index, port->iobase, port->iobase + offset);
490 		port->iobase += offset;
491 	}
492 #endif
493 }
494 
495 static void __init fixup_port_mmio(int index,
496 				   struct device_node *np,
497 				   struct plat_serial8250_port *port)
498 {
499 	DBG("fixup_port_mmio(%d)\n", index);
500 
501 	port->membase = ioremap(port->mapbase, 0x100);
502 }
503 
504 /*
505  * This is called as an arch initcall, hopefully before the PCI bus is
506  * probed and/or the 8250 driver loaded since we need to register our
507  * platform devices before 8250 PCI ones are detected as some of them
508  * must properly "override" the platform ones.
509  *
510  * This function fixes up the interrupt value for platform ports as it
511  * couldn't be done earlier before interrupt maps have been parsed. It
512  * also "corrects" the IO address for PIO ports for the same reason,
513  * since earlier, the PHBs virtual IO space wasn't assigned yet. It then
514  * registers all those platform ports for use by the 8250 driver when it
515  * finally loads.
516  */
517 static int __init serial_dev_init(void)
518 {
519 	int i;
520 
521 	if (legacy_serial_count == 0)
522 		return -ENODEV;
523 
524 	/*
525 	 * Before we register the platform serial devices, we need
526 	 * to fixup their interrupts and their IO ports.
527 	 */
528 	DBG("Fixing serial ports interrupts and IO ports ...\n");
529 
530 	for (i = 0; i < legacy_serial_count; i++) {
531 		struct plat_serial8250_port *port = &legacy_serial_ports[i];
532 		struct device_node *np = legacy_serial_infos[i].np;
533 
534 		if (port->irq == NO_IRQ)
535 			fixup_port_irq(i, np, port);
536 		if (port->iotype == UPIO_PORT)
537 			fixup_port_pio(i, np, port);
538 		if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI))
539 			fixup_port_mmio(i, np, port);
540 	}
541 
542 	DBG("Registering platform serial ports\n");
543 
544 	return platform_device_register(&serial_device);
545 }
546 device_initcall(serial_dev_init);
547 
548 
549 #ifdef CONFIG_SERIAL_8250_CONSOLE
550 /*
551  * This is called very early, as part of console_init() (typically just after
552  * time_init()). This function is respondible for trying to find a good
553  * default console on serial ports. It tries to match the open firmware
554  * default output with one of the available serial console drivers that have
555  * been probed earlier by find_legacy_serial_ports()
556  */
557 static int __init check_legacy_serial_console(void)
558 {
559 	struct device_node *prom_stdout = NULL;
560 	int i, speed = 0, offset = 0;
561 	const char *name;
562 	const __be32 *spd;
563 
564 	DBG(" -> check_legacy_serial_console()\n");
565 
566 	/* The user has requested a console so this is already set up. */
567 	if (strstr(boot_command_line, "console=")) {
568 		DBG(" console was specified !\n");
569 		return -EBUSY;
570 	}
571 
572 	if (!of_chosen) {
573 		DBG(" of_chosen is NULL !\n");
574 		return -ENODEV;
575 	}
576 
577 	if (legacy_serial_console < 0) {
578 		DBG(" legacy_serial_console not found !\n");
579 		return -ENODEV;
580 	}
581 	/* We are getting a weird phandle from OF ... */
582 	/* ... So use the full path instead */
583 	name = of_get_property(of_chosen, "linux,stdout-path", NULL);
584 	if (name == NULL) {
585 		DBG(" no linux,stdout-path !\n");
586 		return -ENODEV;
587 	}
588 	prom_stdout = of_find_node_by_path(name);
589 	if (!prom_stdout) {
590 		DBG(" can't find stdout package %s !\n", name);
591 		return -ENODEV;
592 	}
593 	DBG("stdout is %s\n", prom_stdout->full_name);
594 
595 	name = of_get_property(prom_stdout, "name", NULL);
596 	if (!name) {
597 		DBG(" stdout package has no name !\n");
598 		goto not_found;
599 	}
600 	spd = of_get_property(prom_stdout, "current-speed", NULL);
601 	if (spd)
602 		speed = be32_to_cpup(spd);
603 
604 	if (strcmp(name, "serial") != 0)
605 		goto not_found;
606 
607 	/* Look for it in probed array */
608 	for (i = 0; i < legacy_serial_count; i++) {
609 		if (prom_stdout != legacy_serial_infos[i].np)
610 			continue;
611 		offset = i;
612 		speed = legacy_serial_infos[i].speed;
613 		break;
614 	}
615 	if (i >= legacy_serial_count)
616 		goto not_found;
617 
618 	of_node_put(prom_stdout);
619 
620 	DBG("Found serial console at ttyS%d\n", offset);
621 
622 	if (speed) {
623 		static char __initdata opt[16];
624 		sprintf(opt, "%d", speed);
625 		return add_preferred_console("ttyS", offset, opt);
626 	} else
627 		return add_preferred_console("ttyS", offset, NULL);
628 
629  not_found:
630 	DBG("No preferred console found !\n");
631 	of_node_put(prom_stdout);
632 	return -ENODEV;
633 }
634 console_initcall(check_legacy_serial_console);
635 
636 #endif /* CONFIG_SERIAL_8250_CONSOLE */
637