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