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