Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

Linux/arch/powerpc/kernel/legacy_serial.c

  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 

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