[U-Boot] [PATCH v2 1/5] fdt: Support for ISA busses
Simon Glass
sjg at chromium.org
Tue May 17 14:11:16 CEST 2016
Hi Paul,
On 16 May 2016 at 11:44, Paul Burton <paul.burton at imgtec.com> wrote:
> 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 <paul.burton at imgtec.com>
> ---
>
> Changes in v2:
> - Document the match function pointer in struct of_bus.
> - Make CONFIG_OF_ISA_BUS not user-selectable, and explain it in help text.
> - assert() that of_match_bus didn't fail instead of BUG(), and comment why.
> - s/&of_busses[0]/of_busses/
>
> common/fdt_support.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++--
> drivers/core/Kconfig | 23 ++++++++++++
> 2 files changed, 121 insertions(+), 3 deletions(-)
Reviewed-by: Simon Glass <sjg at chromium.org>
Tiny nit below.
>
> diff --git a/common/fdt_support.c b/common/fdt_support.c
> index 42e5d8a..96b5d0a 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 c5c9d2a..8749561 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
bus'
> + 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
> --
> 2.8.2
>
Regards,
Simon
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