diff options
Diffstat (limited to 'drivers/of/irq.c')
-rw-r--r-- | drivers/of/irq.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/drivers/of/irq.c b/drivers/of/irq.c index 1752988..526cde6 100644 --- a/drivers/of/irq.c +++ b/drivers/of/irq.c @@ -79,6 +79,211 @@ struct device_node *of_irq_find_parent(struct device_node *child) } /** + * of_irq_parse_raw - Low level interrupt tree parsing + * @parent: the device interrupt parent + * @addr: address specifier (start of "reg" property of the device) + * in be32 format + * @out_irq: structure of_irq updated by this function + * + * Returns 0 on success and a negative number on error + * + * This function is a low-level interrupt tree walking function. It + * can be used to do a partial walk with synthetized reg and interrupts + * properties, for example when resolving PCI interrupts when no device + * node exist for the parent. It takes an interrupt specifier structure as + * input, walks the tree looking for any interrupt-map properties, translates + * the specifier for each map, and then returns the translated map. + */ +int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq) +{ + struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL; + __be32 initial_match_array[MAX_PHANDLE_ARGS]; + const __be32 *match_array = initial_match_array; + const __be32 *tmp, *imap, *imask; + const __be32 dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 }; + u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0; + int imaplen, match, i; + +#ifdef DEBUG + of_print_phandle_args("of_irq_parse_raw: ", out_irq); +#endif + + ipar = of_node_get(out_irq->np); + + /* First get the #interrupt-cells property of the current cursor + * that tells us how to interpret the passed-in intspec. If there + * is none, we are nice and just walk up the tree + */ + do { + tmp = of_get_property(ipar, "#interrupt-cells", NULL); + if (tmp != NULL) { + intsize = be32_to_cpu(*tmp); + break; + } + tnode = ipar; + ipar = of_irq_find_parent(ipar); + of_node_put(tnode); + } while (ipar); + if (ipar == NULL) { + pr_debug(" -> no parent found !\n"); + goto fail; + } + + pr_debug("of_irq_parse_raw: ipar=%s, size=%d\n", + of_node_full_name(ipar), intsize); + + if (out_irq->args_count != intsize) + return -EINVAL; + + /* Look for this #address-cells. We have to implement the old linux + * trick of looking for the parent here as some device-trees rely on it + */ + old = of_node_get(ipar); + do { + tmp = of_get_property(old, "#address-cells", NULL); + tnode = of_get_parent(old); + of_node_put(old); + old = tnode; + } while (old && tmp == NULL); + of_node_put(old); + old = NULL; + addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp); + + pr_debug(" -> addrsize=%d\n", addrsize); + + /* Range check so that the temporary buffer doesn't overflow */ + if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)) + goto fail; + + /* Precalculate the match array - this simplifies match loop */ + for (i = 0; i < addrsize; i++) + initial_match_array[i] = addr ? addr[i] : 0; + for (i = 0; i < intsize; i++) + initial_match_array[addrsize + i] = + cpu_to_be32(out_irq->args[i]); + + /* Now start the actual "proper" walk of the interrupt tree */ + while (ipar != NULL) { + /* Now check if cursor is an interrupt-controller and if it is + * then we are done + */ + if (of_get_property(ipar, "interrupt-controller", NULL) != + NULL) { + pr_debug(" -> got it !\n"); + return 0; + } + + /* + * interrupt-map parsing does not work without a reg + * property when #address-cells != 0 + */ + if (addrsize && !addr) { + pr_debug(" -> no reg passed in when needed !\n"); + goto fail; + } + + /* Now look for an interrupt-map */ + imap = of_get_property(ipar, "interrupt-map", &imaplen); + /* No interrupt map, check for an interrupt parent */ + if (imap == NULL) { + pr_debug(" -> no map, getting parent\n"); + newpar = of_irq_find_parent(ipar); + goto skiplevel; + } + imaplen /= sizeof(u32); + + /* Look for a mask */ + imask = of_get_property(ipar, "interrupt-map-mask", NULL); + if (!imask) + imask = dummy_imask; + + /* Parse interrupt-map */ + match = 0; + while (imaplen > (addrsize + intsize + 1) && !match) { + /* Compare specifiers */ + match = 1; + for (i = 0; i < (addrsize + intsize); i++, imaplen--) + match &= !((match_array[i] ^ *imap++) & + imask[i]); + + pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen); + + /* Get the interrupt parent */ + if (of_irq_workarounds & OF_IMAP_NO_PHANDLE) + newpar = of_node_get(of_irq_dflt_pic); + else + newpar = of_find_node_by_phandle( + be32_to_cpup(imap)); + imap++; + --imaplen; + + /* Check if not found */ + if (newpar == NULL) { + pr_debug(" -> imap parent not found !\n"); + goto fail; + } + + if (!of_device_is_available(newpar)) + match = 0; + + /* Get #interrupt-cells and #address-cells of new + * parent + */ + tmp = of_get_property(newpar, "#interrupt-cells", NULL); + if (tmp == NULL) { + pr_debug(" -> parent lacks #interrupt-cells!\n"); + goto fail; + } + newintsize = be32_to_cpu(*tmp); + tmp = of_get_property(newpar, "#address-cells", NULL); + newaddrsize = (tmp == NULL) ? 0 : be32_to_cpu(*tmp); + + pr_debug(" -> newintsize=%d, newaddrsize=%d\n", + newintsize, newaddrsize); + + /* Check for malformed properties */ + if (WARN_ON(newaddrsize + newintsize > + MAX_PHANDLE_ARGS)) + goto fail; + if (imaplen < (newaddrsize + newintsize)) + goto fail; + + imap += newaddrsize + newintsize; + imaplen -= newaddrsize + newintsize; + + pr_debug(" -> imaplen=%d\n", imaplen); + } + if (!match) + goto fail; + + /* + * Successfully parsed an interrrupt-map translation; copy new + * interrupt specifier into the out_irq structure + */ + out_irq->np = newpar; + + match_array = imap - newaddrsize - newintsize; + for (i = 0; i < newintsize; i++) + out_irq->args[i] = be32_to_cpup(imap - newintsize + i); + out_irq->args_count = intsize = newintsize; + addrsize = newaddrsize; + +skiplevel: + /* Iterate again with new parent */ + pr_debug(" -> new parent: %s\n", of_node_full_name(newpar)); + of_node_put(ipar); + ipar = newpar; + newpar = NULL; + } + fail: + of_node_put(ipar); + of_node_put(newpar); + + return -EINVAL; +} +EXPORT_SYMBOL_GPL(of_irq_parse_raw); + +/** * of_irq_map_raw - Low level interrupt tree parsing * @parent: the device interrupt parent * @intspec: interrupt specifier ("interrupts" property of the device) @@ -272,6 +477,77 @@ int of_irq_map_raw(struct device_node *parent, const __be32 *intspec, EXPORT_SYMBOL_GPL(of_irq_map_raw); /** + * of_irq_parse_one - Resolve an interrupt for a device + * @device: the device whose interrupt is to be resolved + * @index: index of the interrupt to resolve + * @out_irq: structure of_irq filled by this function + * + * This function resolves an interrupt for a node by walking the interrupt tree, + * finding which interrupt controller node it is attached to, and returning the + * interrupt specifier that can be used to retrieve a Linux IRQ number. + */ +int of_irq_parse_one(struct device_node *device, int index, + struct of_phandle_args *out_irq) +{ + struct device_node *p; + const __be32 *intspec, *tmp, *addr; + u32 intsize, intlen; + int i, res = -EINVAL; + + pr_debug("of_irq_parse_one: dev=%s, index=%d\n", + of_node_full_name(device), index); + + /* Get the reg property (if any) */ + addr = of_get_property(device, "reg", NULL); + + /* Try the new-style interrupts-extended first */ + res = of_parse_phandle_with_args(device, "interrupts-extended", + "#interrupt-cells", index, out_irq); + if (!res) + return of_irq_parse_raw(addr, out_irq); + + /* Get the interrupts property */ + intspec = of_get_property(device, "interrupts", &intlen); + if (intspec == NULL) + return -EINVAL; + + intlen /= sizeof(*intspec); + + pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen); + + /* Look for the interrupt parent. */ + p = of_irq_find_parent(device); + if (p == NULL) + return -EINVAL; + + /* Get size of interrupt specifier */ + tmp = of_get_property(p, "#interrupt-cells", NULL); + if (tmp == NULL) + goto out; + intsize = be32_to_cpu(*tmp); + + pr_debug(" intsize=%d intlen=%d\n", intsize, intlen); + + /* Check index */ + if ((index + 1) * intsize > intlen) + goto out; + + /* Copy intspec into irq structure */ + intspec += index * intsize; + out_irq->np = p; + out_irq->args_count = intsize; + for (i = 0; i < intsize; i++) + out_irq->args[i] = be32_to_cpup(intspec++); + + /* Check if there are any interrupt-map translations to process */ + res = of_irq_parse_raw(addr, out_irq); + out: + of_node_put(p); + return res; +} +EXPORT_SYMBOL_GPL(of_irq_parse_one); + +/** * of_irq_map_one - Resolve an interrupt for a device * @device: the device whose interrupt is to be resolved * @index: index of the interrupt to resolve |