From 0a222d53d81cbd4f7a440a6f83e243a7b4e80544 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Tue, 17 May 2016 07:43:24 +0100 Subject: [PATCH] fdt: Support for ISA busses Support ISA busses in much the same way as Linux does. This allows for ISA bus addresses to be translated, and only if CONFIG_OF_ISA_BUS is selected in order to avoid including the code in builds which won't need it. Signed-off-by: Paul Burton Reviewed-by: Simon Glass --- common/fdt_support.c | 101 +++++++++++++++++++++++++++++++++++++++++-- drivers/core/Kconfig | 23 ++++++++++ 2 files changed, 121 insertions(+), 3 deletions(-) diff --git a/common/fdt_support.c b/common/fdt_support.c index 42e5d8a1d2..96b5d0aa4e 100644 --- a/common/fdt_support.c +++ b/common/fdt_support.c @@ -964,10 +964,21 @@ static void of_dump_addr(const char *s, const fdt32_t *addr, int na) static void of_dump_addr(const char *s, const fdt32_t *addr, int na) { } #endif -/* Callbacks for bus specific translators */ +/** + * struct of_bus - Callbacks for bus specific translators + * @match: Return non-zero if the node whose parent is at + * parentoffset in the FDT blob corresponds to a bus + * of this type, otherwise return zero. If NULL a match + * is assumed. + * + * Each bus type will include a struct of_bus in the of_busses array, + * providing implementations of some or all of the functions used to + * match the bus & handle address translation for its children. + */ struct of_bus { const char *name; const char *addresses; + int (*match)(void *blob, int parentoffset); void (*count_cells)(void *blob, int parentoffset, int *addrc, int *sizec); u64 (*map)(fdt32_t *addr, const fdt32_t *range, @@ -1022,8 +1033,70 @@ static int of_bus_default_translate(fdt32_t *addr, u64 offset, int na) return 0; } +#ifdef CONFIG_OF_ISA_BUS + +/* ISA bus translator */ +static int of_bus_isa_match(void *blob, int parentoffset) +{ + const char *name; + + name = fdt_get_name(blob, parentoffset, NULL); + if (!name) + return 0; + + return !strcmp(name, "isa"); +} + +static void of_bus_isa_count_cells(void *blob, int parentoffset, + int *addrc, int *sizec) +{ + if (addrc) + *addrc = 2; + if (sizec) + *sizec = 1; +} + +static u64 of_bus_isa_map(fdt32_t *addr, const fdt32_t *range, + int na, int ns, int pna) +{ + u64 cp, s, da; + + /* Check address type match */ + if ((addr[0] ^ range[0]) & cpu_to_be32(1)) + return OF_BAD_ADDR; + + cp = of_read_number(range + 1, na - 1); + s = of_read_number(range + na + pna, ns); + da = of_read_number(addr + 1, na - 1); + + debug("OF: ISA map, cp=%" PRIu64 ", s=%" PRIu64 + ", da=%" PRIu64 "\n", cp, s, da); + + if (da < cp || da >= (cp + s)) + return OF_BAD_ADDR; + return da - cp; +} + +static int of_bus_isa_translate(fdt32_t *addr, u64 offset, int na) +{ + return of_bus_default_translate(addr + 1, offset, na - 1); +} + +#endif /* CONFIG_OF_ISA_BUS */ + /* Array of bus specific translators */ static struct of_bus of_busses[] = { +#ifdef CONFIG_OF_ISA_BUS + /* ISA */ + { + .name = "isa", + .addresses = "reg", + .match = of_bus_isa_match, + .count_cells = of_bus_isa_count_cells, + .map = of_bus_isa_map, + .translate = of_bus_isa_translate, + }, +#endif /* CONFIG_OF_ISA_BUS */ /* Default */ { .name = "default", @@ -1034,6 +1107,28 @@ static struct of_bus of_busses[] = { }, }; +static struct of_bus *of_match_bus(void *blob, int parentoffset) +{ + struct of_bus *bus; + + if (ARRAY_SIZE(of_busses) == 1) + return of_busses; + + for (bus = of_busses; bus; bus++) { + if (!bus->match || bus->match(blob, parentoffset)) + return bus; + } + + /* + * We should always have matched the default bus at least, since + * it has a NULL match field. If we didn't then it somehow isn't + * in the of_busses array or something equally catastrophic has + * gone wrong. + */ + assert(0); + return NULL; +} + static int of_translate_one(void * blob, int parent, struct of_bus *bus, struct of_bus *pbus, fdt32_t *addr, int na, int ns, int pna, const char *rprop) @@ -1113,7 +1208,7 @@ static u64 __of_translate_address(void *blob, int node_offset, const fdt32_t *in parent = fdt_parent_offset(blob, node_offset); if (parent < 0) goto bail; - bus = &of_busses[0]; + bus = of_match_bus(blob, parent); /* Cound address cells & copy address locally */ bus->count_cells(blob, parent, &na, &ns); @@ -1142,7 +1237,7 @@ static u64 __of_translate_address(void *blob, int node_offset, const fdt32_t *in } /* Get new parent bus and counts */ - pbus = &of_busses[0]; + pbus = of_match_bus(blob, parent); pbus->count_cells(blob, parent, &pna, &pns); if (!OF_CHECK_COUNTS(pna, pns)) { printf("%s: Bad cell count for %s\n", __FUNCTION__, diff --git a/drivers/core/Kconfig b/drivers/core/Kconfig index c5c9d2a42e..87495614c2 100644 --- a/drivers/core/Kconfig +++ b/drivers/core/Kconfig @@ -178,4 +178,27 @@ config SPL_OF_TRANSLATE used for the address translation. This function is faster and smaller in size than fdt_translate_address(). +config OF_ISA_BUS + bool + depends on OF_TRANSLATE + help + Is this option is enabled then support for the ISA bus will + be included for addresses read from DT. This is something that + should be known to be required or not based upon the board + being targetted, and whether or not it makes use of an ISA bus. + + The bus is matched based upon its node name equalling "isa". The + busses #address-cells should equal 2, with the first cell being + used to hold flags & flag 0x1 indicating that the address range + should be accessed using I/O port in/out accessors. The second + cell holds the offset into ISA bus address space. The #size-cells + property should equal 1, and of course holds the size of the + address range used by a device. + + If this option is not enabled then support for the ISA bus is + not included and any such busses used in DT will be treated as + typical simple-bus compatible busses. This will lead to + mistranslation of device addresses, so ensure that this is + enabled if your board does include an ISA bus. + endmenu -- 2.39.5