Version:  2.0.40 2.2.26 2.4.37 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 3.16 3.17 3.18

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

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