1 // SPDX-License-Identifier: GPL-2.0
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 <linux/of.h>
9 #include <linux/of_address.h>
10 #include <linux/of_irq.h>
11 #include <linux/serial_reg.h>
12 #include <asm/io.h>
13 #include <asm/mmu.h>
14 #include <asm/serial.h>
15 #include <asm/udbg.h>
16 #include <asm/pci-bridge.h>
17 #include <asm/ppc-pci.h>
18 #include <asm/early_ioremap.h>
19
20 #undef DEBUG
21
22 #ifdef DEBUG
23 #define DBG(fmt...) do { printk(fmt); } while(0)
24 #else
25 #define DBG(fmt...) do { } while(0)
26 #endif
27
28 #define MAX_LEGACY_SERIAL_PORTS 8
29
30 static struct plat_serial8250_port
31 legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1];
32 static struct legacy_serial_info {
33 struct device_node *np;
34 unsigned int speed;
35 unsigned int clock;
36 int irq_check_parent;
37 phys_addr_t taddr;
38 void __iomem *early_addr;
39 } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
40
41 static const struct of_device_id legacy_serial_parents[] __initconst = {
42 {.type = "soc",},
43 {.type = "tsi-bridge",},
44 {.type = "opb", },
45 {.compatible = "ibm,opb",},
46 {.compatible = "simple-bus",},
47 {.compatible = "wrs,epld-localbus",},
48 {},
49 };
50
51 static unsigned int legacy_serial_count;
52 static int legacy_serial_console = -1;
53
54 static const upf_t legacy_port_flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST |
55 UPF_SHARE_IRQ | UPF_FIXED_PORT;
56
57 static unsigned int tsi_serial_in(struct uart_port *p, int offset)
58 {
59 unsigned int tmp;
60 offset = offset << p->regshift;
61 if (offset == UART_IIR) {
62 tmp = readl(p->membase + (UART_IIR & ~3));
63 return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
64 } else
65 return readb(p->membase + offset);
66 }
67
68 static void tsi_serial_out(struct uart_port *p, int offset, int value)
69 {
70 offset = offset << p->regshift;
71 if (!((offset == UART_IER) && (value & UART_IER_UUE)))
72 writeb(value, p->membase + offset);
73 }
74
75 static int __init add_legacy_port(struct device_node *np, int want_index,
76 int iotype, phys_addr_t base,
77 phys_addr_t taddr, unsigned long irq,
78 upf_t flags, int irq_check_parent)
79 {
80 const __be32 *clk, *spd, *rs;
81 u32 clock = BASE_BAUD * 16;
82 u32 shift = 0;
83 int index;
84
85 /* get clock freq. if present */
86 clk = of_get_property(np, "clock-frequency", NULL);
87 if (clk && *clk)
88 clock = be32_to_cpup(clk);
89
90 /* get default speed if present */
91 spd = of_get_property(np, "current-speed", NULL);
92
93 /* get register shift if present */
94 rs = of_get_property(np, "reg-shift", NULL);
95 if (rs && *rs)
96 shift = be32_to_cpup(rs);
97
98 /* If we have a location index, then try to use it */
99 if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS)
100 index = want_index;
101 else
102 index = legacy_serial_count;
103
104 /* if our index is still out of range, that mean that
105 * array is full, we could scan for a free slot but that
106 * make little sense to bother, just skip the port
107 */
108 if (index >= MAX_LEGACY_SERIAL_PORTS)
109 return -1;
110 if (index >= legacy_serial_count)
111 legacy_serial_count = index + 1;
112
113 /* Check if there is a port who already claimed our slot */
114 if (legacy_serial_infos[index].np != NULL) {
115 /* if we still have some room, move it, else override */
116 if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
117 printk(KERN_DEBUG "Moved legacy port %d -> %d\n",
118 index, legacy_serial_count);
119 legacy_serial_ports[legacy_serial_count] =
120 legacy_serial_ports[index];
121 legacy_serial_infos[legacy_serial_count] =
122 legacy_serial_infos[index];
123 legacy_serial_count++;
124 } else {
125 printk(KERN_DEBUG "Replacing legacy port %d\n", index);
126 }
127 }
128
129 /* Now fill the entry */
130 memset(&legacy_serial_ports[index], 0,
131 sizeof(struct plat_serial8250_port));
132 if (iotype == UPIO_PORT)
133 legacy_serial_ports[index].iobase = base;
134 else
135 legacy_serial_ports[index].mapbase = base;
136
137 legacy_serial_ports[index].iotype = iotype;
138 legacy_serial_ports[index].uartclk = clock;
139 legacy_serial_ports[index].irq = irq;
140 legacy_serial_ports[index].flags = flags;
141 legacy_serial_ports[index].regshift = shift;
142 legacy_serial_infos[index].taddr = taddr;
143 legacy_serial_infos[index].np = of_node_get(np);
144 legacy_serial_infos[index].clock = clock;
145 legacy_serial_infos[index].speed = spd ? be32_to_cpup(spd) : 0;
146 legacy_serial_infos[index].irq_check_parent = irq_check_parent;
147
148 if (iotype == UPIO_TSI) {
149 legacy_serial_ports[index].serial_in = tsi_serial_in;
150 legacy_serial_ports[index].serial_out = tsi_serial_out;
151 }
152
153 printk(KERN_DEBUG "Found legacy serial port %d for %pOF\n",
154 index, np);
155 printk(KERN_DEBUG " %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
156 (iotype == UPIO_PORT) ? "port" : "mem",
157 (unsigned long long)base, (unsigned long long)taddr, irq,
158 legacy_serial_ports[index].uartclk,
159 legacy_serial_infos[index].speed);
160
161 return index;
162 }
163
164 static int __init add_legacy_soc_port(struct device_node *np,
165 struct device_node *soc_dev)
166 {
167 u64 addr;
168 const __be32 *addrp;
169 struct device_node *tsi = of_get_parent(np);
170
171 /* We only support ports that have a clock frequency properly
172 * encoded in the device-tree.
173 */
174 if (!of_property_present(np, "clock-frequency"))
175 return -1;
176
177 /* if reg-offset don't try to use it */
178 if (of_property_present(np, "reg-offset"))
179 return -1;
180
181 /* if rtas uses this device, don't try to use it as well */
182 if (of_property_read_bool(np, "used-by-rtas"))
183 return -1;
184
185 /* Get the address */
186 addrp = of_get_address(soc_dev, 0, NULL, NULL);
187 if (addrp == NULL)
188 return -1;
189
190 addr = of_translate_address(soc_dev, addrp);
191 if (addr == OF_BAD_ADDR)
192 return -1;
193
194 /* Add port, irq will be dealt with later. We passed a translated
195 * IO port value. It will be fixed up later along with the irq
196 */
197 if (of_node_is_type(tsi, "tsi-bridge"))
198 return add_legacy_port(np, -1, UPIO_TSI, addr, addr,
199 0, legacy_port_flags, 0);
200 else
201 return add_legacy_port(np, -1, UPIO_MEM, addr, addr,
202 0, legacy_port_flags, 0);
203 }
204
205 static int __init add_legacy_isa_port(struct device_node *np,
206 struct device_node *isa_brg)
207 {
208 const __be32 *reg;
209 const char *typep;
210 int index = -1;
211 u64 taddr;
212
213 DBG(" -> add_legacy_isa_port(%pOF)\n", np);
214
215 /* Get the ISA port number */
216 reg = of_get_property(np, "reg", NULL);
217 if (reg == NULL)
218 return -1;
219
220 /* Verify it's an IO port, we don't support anything else */
221 if (!(be32_to_cpu(reg[0]) & 0x00000001))
222 return -1;
223
224 /* Now look for an "ibm,aix-loc" property that gives us ordering
225 * if any...
226 */
227 typep = of_get_property(np, "ibm,aix-loc", NULL);
228
229 /* If we have a location index, then use it */
230 if (typep && *typep == 'S')
231 index = simple_strtol(typep+1, NULL, 0) - 1;
232
233 /* Translate ISA address. If it fails, we still register the port
234 * with no translated address so that it can be picked up as an IO
235 * port later by the serial driver
236 *
237 * Note: Don't even try on P8 lpc, we know it's not directly mapped
238 */
239 if (!of_device_is_compatible(isa_brg, "ibm,power8-lpc") ||
240 of_property_present(isa_brg, "ranges")) {
241 taddr = of_translate_address(np, reg);
242 if (taddr == OF_BAD_ADDR)
243 taddr = 0;
244 } else
245 taddr = 0;
246
247 /* Add port, irq will be dealt with later */
248 return add_legacy_port(np, index, UPIO_PORT, be32_to_cpu(reg[1]),
249 taddr, 0, legacy_port_flags, 0);
250
251 }
252
253 #ifdef CONFIG_PCI
254 static int __init add_legacy_pci_port(struct device_node *np,
255 struct device_node *pci_dev)
256 {
257 u64 addr, base;
258 const __be32 *addrp;
259 unsigned int flags;
260 int iotype, index = -1, lindex = 0;
261
262 DBG(" -> add_legacy_pci_port(%pOF)\n", np);
263
264 /* We only support ports that have a clock frequency properly
265 * encoded in the device-tree (that is have an fcode). Anything
266 * else can't be used that early and will be normally probed by
267 * the generic 8250_pci driver later on. The reason is that 8250
268 * compatible UARTs on PCI need all sort of quirks (port offsets
269 * etc...) that this code doesn't know about
270 */
271 if (!of_property_present(np, "clock-frequency"))
272 return -1;
273
274 /* Get the PCI address. Assume BAR 0 */
275 addrp = of_get_pci_address(pci_dev, 0, NULL, &flags);
276 if (addrp == NULL)
277 return -1;
278
279 /* We only support BAR 0 for now */
280 iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT;
281 addr = of_translate_address(pci_dev, addrp);
282 if (addr == OF_BAD_ADDR)
283 return -1;
284
285 /* Set the IO base to the same as the translated address for MMIO,
286 * or to the domain local IO base for PIO (it will be fixed up later)
287 */
288 if (iotype == UPIO_MEM)
289 base = addr;
290 else
291 base = of_read_number(&addrp[2], 1);
292
293 /* Try to guess an index... If we have subdevices of the pci dev,
294 * we get to their "reg" property
295 */
296 if (np != pci_dev) {
297 const __be32 *reg = of_get_property(np, "reg", NULL);
298 if (reg && (be32_to_cpup(reg) < 4))
299 index = lindex = be32_to_cpup(reg);
300 }
301
302 /* Local index means it's the Nth port in the PCI chip. Unfortunately
303 * the offset to add here is device specific. We know about those
304 * EXAR ports and we default to the most common case. If your UART
305 * doesn't work for these settings, you'll have to add your own special
306 * cases here
307 */
308 if (of_device_is_compatible(pci_dev, "pci13a8,152") ||
309 of_device_is_compatible(pci_dev, "pci13a8,154") ||
310 of_device_is_compatible(pci_dev, "pci13a8,158")) {
311 addr += 0x200 * lindex;
312 base += 0x200 * lindex;
313 } else {
314 addr += 8 * lindex;
315 base += 8 * lindex;
316 }
317
318 /* Add port, irq will be dealt with later. We passed a translated
319 * IO port value. It will be fixed up later along with the irq
320 */
321 return add_legacy_port(np, index, iotype, base, addr, 0,
322 legacy_port_flags, np != pci_dev);
323 }
324 #endif
325
326 static void __init setup_legacy_serial_console(int console)
327 {
328 struct legacy_serial_info *info = &legacy_serial_infos[console];
329 struct plat_serial8250_port *port = &legacy_serial_ports[console];
330 unsigned int stride;
331
332 stride = 1 << port->regshift;
333
334 /* Check if a translated MMIO address has been found */
335 if (info->taddr) {
336 info->early_addr = early_ioremap(info->taddr, 0x1000);
337 if (info->early_addr == NULL)
338 return;
339 udbg_uart_init_mmio(info->early_addr, stride);
340 } else {
341 /* Check if it's PIO and we support untranslated PIO */
342 if (port->iotype == UPIO_PORT && isa_io_special)
343 udbg_uart_init_pio(port->iobase, stride);
344 else
345 return;
346 }
347
348 /* Try to query the current speed */
349 if (info->speed == 0)
350 info->speed = udbg_probe_uart_speed(info->clock);
351
352 /* Set it up */
353 DBG("default console speed = %d\n", info->speed);
354 udbg_uart_setup(info->speed, info->clock);
355 }
356
357 static int __init ioremap_legacy_serial_console(void)
358 {
359 struct plat_serial8250_port *port;
360 struct legacy_serial_info *info;
361 void __iomem *vaddr;
362
363 if (legacy_serial_console < 0)
364 return 0;
365
366 info = &legacy_serial_infos[legacy_serial_console];
367 port = &legacy_serial_ports[legacy_serial_console];
368
369 if (!info->early_addr)
370 return 0;
371
372 vaddr = ioremap(info->taddr, 0x1000);
373 if (WARN_ON(!vaddr))
374 return -ENOMEM;
375
376 udbg_uart_init_mmio(vaddr, 1 << port->regshift);
377 early_iounmap(info->early_addr, 0x1000);
378 info->early_addr = NULL;
379
380 return 0;
381 }
382 early_initcall(ioremap_legacy_serial_console);
383
384 /*
385 * This is called very early, as part of setup_system() or eventually
386 * setup_arch(), basically before anything else in this file. This function
387 * will try to build a list of all the available 8250-compatible serial ports
388 * in the machine using the Open Firmware device-tree. It currently only deals
389 * with ISA and PCI busses but could be extended. It allows a very early boot
390 * console to be initialized, that list is also used later to provide 8250 with
391 * the machine non-PCI ports and to properly pick the default console port
392 */
393 void __init find_legacy_serial_ports(void)
394 {
395 struct device_node *np, *stdout = NULL;
396 const char *path;
397 int index;
398
399 DBG(" -> find_legacy_serial_port()\n");
400
401 /* Now find out if one of these is out firmware console */
402 path = of_get_property(of_chosen, "linux,stdout-path", NULL);
403 if (path == NULL)
404 path = of_get_property(of_chosen, "stdout-path", NULL);
405 if (path != NULL) {
406 stdout = of_find_node_by_path(path);
407 if (stdout)
408 DBG("stdout is %pOF\n", stdout);
409 } else {
410 DBG(" no linux,stdout-path !\n");
411 }
412
413 /* Iterate over all the 16550 ports, looking for known parents */
414 for_each_compatible_node(np, "serial", "ns16550") {
415 struct device_node *parent = of_get_parent(np);
416 if (!parent)
417 continue;
418 if (of_match_node(legacy_serial_parents, parent) != NULL) {
419 if (of_device_is_available(np)) {
420 index = add_legacy_soc_port(np, np);
421 if (index >= 0 && np == stdout)
422 legacy_serial_console = index;
423 }
424 }
425 of_node_put(parent);
426 }
427
428 /* Next, fill our array with ISA ports */
429 for_each_node_by_type(np, "serial") {
430 struct device_node *isa = of_get_parent(np);
431 if (of_node_name_eq(isa, "isa") || of_node_name_eq(isa, "lpc")) {
432 if (of_device_is_available(np)) {
433 index = add_legacy_isa_port(np, isa);
434 if (index >= 0 && np == stdout)
435 legacy_serial_console = index;
436 }
437 }
438 of_node_put(isa);
439 }
440
441 #ifdef CONFIG_PCI
442 /* Next, try to locate PCI ports */
443 for (np = NULL; (np = of_find_all_nodes(np));) {
444 struct device_node *pci, *parent = of_get_parent(np);
445 if (of_node_name_eq(parent, "isa")) {
446 of_node_put(parent);
447 continue;
448 }
449 if (!of_node_name_eq(np, "serial") &&
450 !of_node_is_type(np, "serial")) {
451 of_node_put(parent);
452 continue;
453 }
454 /* Check for known pciclass, and also check whether we have
455 * a device with child nodes for ports or not
456 */
457 if (of_device_is_compatible(np, "pciclass,0700") ||
458 of_device_is_compatible(np, "pciclass,070002"))
459 pci = np;
460 else if (of_device_is_compatible(parent, "pciclass,0700") ||
461 of_device_is_compatible(parent, "pciclass,070002"))
462 pci = parent;
463 else {
464 of_node_put(parent);
465 continue;
466 }
467 index = add_legacy_pci_port(np, pci);
468 if (index >= 0 && np == stdout)
469 legacy_serial_console = index;
470 of_node_put(parent);
471 }
472 #endif
473
474 of_node_put(stdout);
475
476 DBG("legacy_serial_console = %d\n", legacy_serial_console);
477 if (legacy_serial_console >= 0)
478 setup_legacy_serial_console(legacy_serial_console);
479 DBG(" <- find_legacy_serial_port()\n");
480 }
481
482 static struct platform_device serial_device = {
483 .name = "serial8250",
484 .id = PLAT8250_DEV_PLATFORM,
485 .dev = {
486 .platform_data = legacy_serial_ports,
487 },
488 };
489
490 static void __init fixup_port_irq(int index,
491 struct device_node *np,
492 struct plat_serial8250_port *port)
493 {
494 unsigned int virq;
495
496 DBG("fixup_port_irq(%d)\n", index);
497
498 virq = irq_of_parse_and_map(np, 0);
499 if (!virq && legacy_serial_infos[index].irq_check_parent) {
500 np = of_get_parent(np);
501 if (np == NULL)
502 return;
503 virq = irq_of_parse_and_map(np, 0);
504 of_node_put(np);
505 }
506 if (!virq)
507 return;
508
509 port->irq = virq;
510
511 if (IS_ENABLED(CONFIG_SERIAL_8250) &&
512 of_device_is_compatible(np, "fsl,ns16550")) {
513 if (IS_REACHABLE(CONFIG_SERIAL_8250_FSL)) {
514 port->handle_irq = fsl8250_handle_irq;
515 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
516 } else {
517 pr_warn_once("Not activating Freescale specific workaround for device %pOFP\n",
518 np);
519 }
520 }
521 }
522
523 static void __init fixup_port_pio(int index,
524 struct device_node *np,
525 struct plat_serial8250_port *port)
526 {
527 #ifdef CONFIG_PCI
528 struct pci_controller *hose;
529
530 DBG("fixup_port_pio(%d)\n", index);
531
532 hose = pci_find_hose_for_OF_device(np);
533 if (hose) {
534 unsigned long offset = (unsigned long)hose->io_base_virt -
535 #ifdef CONFIG_PPC64
536 pci_io_base;
537 #else
538 isa_io_base;
539 #endif
540 DBG("port %d, IO %lx -> %lx\n",
541 index, port->iobase, port->iobase + offset);
542 port->iobase += offset;
543 }
544 #endif
545 }
546
547 static void __init fixup_port_mmio(int index,
548 struct device_node *np,
549 struct plat_serial8250_port *port)
550 {
551 DBG("fixup_port_mmio(%d)\n", index);
552
553 port->membase = ioremap(port->mapbase, 0x100);
554 }
555
556 /*
557 * This is called as an arch initcall, hopefully before the PCI bus is
558 * probed and/or the 8250 driver loaded since we need to register our
559 * platform devices before 8250 PCI ones are detected as some of them
560 * must properly "override" the platform ones.
561 *
562 * This function fixes up the interrupt value for platform ports as it
563 * couldn't be done earlier before interrupt maps have been parsed. It
564 * also "corrects" the IO address for PIO ports for the same reason,
565 * since earlier, the PHBs virtual IO space wasn't assigned yet. It then
566 * registers all those platform ports for use by the 8250 driver when it
567 * finally loads.
568 */
569 static int __init serial_dev_init(void)
570 {
571 int i;
572
573 if (legacy_serial_count == 0)
574 return -ENODEV;
575
576 /*
577 * Before we register the platform serial devices, we need
578 * to fixup their interrupts and their IO ports.
579 */
580 DBG("Fixing serial ports interrupts and IO ports ...\n");
581
582 for (i = 0; i < legacy_serial_count; i++) {
583 struct plat_serial8250_port *port = &legacy_serial_ports[i];
584 struct device_node *np = legacy_serial_infos[i].np;
585
586 if (!port->irq)
587 fixup_port_irq(i, np, port);
588 if (port->iotype == UPIO_PORT)
589 fixup_port_pio(i, np, port);
590 if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI))
591 fixup_port_mmio(i, np, port);
592 }
593
594 DBG("Registering platform serial ports\n");
595
596 return platform_device_register(&serial_device);
597 }
598 device_initcall(serial_dev_init);
599
600
601 #ifdef CONFIG_SERIAL_8250_CONSOLE
602 /*
603 * This is called very early, as part of console_init() (typically just after
604 * time_init()). This function is respondible for trying to find a good
605 * default console on serial ports. It tries to match the open firmware
606 * default output with one of the available serial console drivers that have
607 * been probed earlier by find_legacy_serial_ports()
608 */
609 static int __init check_legacy_serial_console(void)
610 {
611 struct device_node *prom_stdout = NULL;
612 int i, speed = 0, offset = 0;
613 const char *name;
614 const __be32 *spd;
615
616 DBG(" -> check_legacy_serial_console()\n");
617
618 /* The user has requested a console so this is already set up. */
619 if (strstr(boot_command_line, "console=")) {
620 DBG(" console was specified !\n");
621 return -EBUSY;
622 }
623
624 if (!of_chosen) {
625 DBG(" of_chosen is NULL !\n");
626 return -ENODEV;
627 }
628
629 if (legacy_serial_console < 0) {
630 DBG(" legacy_serial_console not found !\n");
631 return -ENODEV;
632 }
633 /* We are getting a weird phandle from OF ... */
634 /* ... So use the full path instead */
635 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
636 if (name == NULL)
637 name = of_get_property(of_chosen, "stdout-path", NULL);
638 if (name == NULL) {
639 DBG(" no stdout-path !\n");
640 return -ENODEV;
641 }
642 prom_stdout = of_find_node_by_path(name);
643 if (!prom_stdout) {
644 DBG(" can't find stdout package %s !\n", name);
645 return -ENODEV;
646 }
647 DBG("stdout is %pOF\n", prom_stdout);
648
649 name = of_get_property(prom_stdout, "name", NULL);
650 if (!name) {
651 DBG(" stdout package has no name !\n");
652 goto not_found;
653 }
654 spd = of_get_property(prom_stdout, "current-speed", NULL);
655 if (spd)
656 speed = be32_to_cpup(spd);
657
658 if (strcmp(name, "serial") != 0)
659 goto not_found;
660
661 /* Look for it in probed array */
662 for (i = 0; i < legacy_serial_count; i++) {
663 if (prom_stdout != legacy_serial_infos[i].np)
664 continue;
665 offset = i;
666 speed = legacy_serial_infos[i].speed;
667 break;
668 }
669 if (i >= legacy_serial_count)
670 goto not_found;
671
672 of_node_put(prom_stdout);
673
674 DBG("Found serial console at ttyS%d\n", offset);
675
676 if (speed) {
677 static char __initdata opt[16];
678 sprintf(opt, "%d", speed);
679 return add_preferred_console("ttyS", offset, opt);
680 } else
681 return add_preferred_console("ttyS", offset, NULL);
682
683 not_found:
684 DBG("No preferred console found !\n");
685 of_node_put(prom_stdout);
686 return -ENODEV;
687 }
688 console_initcall(check_legacy_serial_console);
689
690 #endif /* CONFIG_SERIAL_8250_CONSOLE */
691
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