[U-Boot] [PATCH v3 1/5] fdt: Support for ISA busses
Paul Burton
paul.burton at imgtec.com
Tue May 17 08:43:24 CEST 2016
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 v3: None
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(-)
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
+ 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
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