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 <paul.burton@imgtec.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Paul Burton 2016-05-17 07:43:24 +01:00 committed by Daniel Schwierzeck
parent fc15b9beed
commit 0a222d53d8
2 changed files with 121 additions and 3 deletions

View File

@ -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__,

View File

@ -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