Currently nodes with phandles just print out as plain integer values, e.g.
$ fdtget firefly-rk3288/u-boot.dtb /gpio-keys/button@0 gpios
112 5 1
A common use of phandles is:
<phandle> <n cells of stuff> <phandle> <m cells of stuff>
It is useful to be able to decode these phandles and print them out in a
properly formatted way, e.g.
$ fdtget firefly-rk3288/u-boot.dtb -P -c gpio /gpio-keys/button@0 gpios
/pinctrl/gpio0@ff750000 5 1
Add a -P option to decode these sorts of phandles. For those which require
arguments, add a -c option to specify the name of the '#xxx-cells' property
in the target node. This allows the tool to look up the number of cells
that follow each phandle.
This feature covers a common use of phandles. Of course it is not possible
to detect phandles automatically and other uses of phandles will not be
correctly displayed by this feature.
Signed-off-by: Simon Glass <sjg@xxxxxxxxxxxx>
---
Changes in v3:
- Change flag from -f to -P
- Change long flag from --phandle to --decode-phandles
- Update tests so that we use the --decode-phandles option as well as -P
- Add a new test for properties that don't contain phandles
Changes in v2:
- Use 'decode' rather than 'follow'
- Be more specific in the commit message about what is and isn't supported
- Drop the unnecessary phandle_start variable
fdtget.c | 120 ++++++++++++++++++++++++++++++++++++++++++---
tests/label01.dts | 31 ++++++++++++
tests/run_tests.sh | 19 +++++++
3 files changed, 163 insertions(+), 7 deletions(-)
diff --git a/fdtget.c b/fdtget.c
index 34d8194..e5f3783 100644
--- a/fdtget.c
+++ b/fdtget.c
@@ -46,6 +46,10 @@ struct display_info {
int size; /* data size (1/2/4) */
enum display_mode mode; /* display mode that we are using */
const char *default_val; /* default value if node/property not found */
+
+ int decode_phandles; /* detect, decode and show phandle values */
+ /* property which defines the number of argument cells for a phandle */
+ char *phandle_cells;
};
static void report_error(const char *where, int err)
@@ -53,6 +57,63 @@ static void report_error(const char *where, int err)
fprintf(stderr, "Error at '%s': %s\n", where, fdt_strerror(err));
}
+/**
+ * Decodes and shows the target path of a phandle
+ *
+ * This looks up a phandle and displays the full path of the target node. If
+ * the property value does not correctly decode as a phandle according to the
+ * supported format, it returns an error.
+ *
+ * @param disp Display information / options
+ * @param value Phandle value to look up
+ * @param blob Device tree blob (for looking up phandles)
+ * @return number of arguments expected, or -1 on error
+ */
+static int decode_phandle_target(struct display_info *disp, int value,
+ const char *blob)
+{
+ const void *cells_prop;
+ int phandle_args = 0;
+ int cells_size;
+ char buf[256];
+ int target;
+ int ret;
+
+ target = fdt_node_offset_by_phandle(blob, value);
+ if (target < 0) {
+ printf("invalid_%d", value);
+ return -1;
+ }
+
+ if (disp->phandle_cells) {
+ cells_prop = fdt_getprop(blob, target, disp->phandle_cells,
+ &cells_size);
+ if (!cells_prop) {
+ fprintf(stderr, "Expected node '%s' to have property "
+ "'%s' but it is missing\n",
+ fdt_get_name(blob, target, NULL),
+ disp->phandle_cells);
+ return -1;
+ }
+ if (cells_size != 4) {
+ fprintf(stderr, "Expected node '%s' property '%s' size "
+ "to be 4, but it is %d\n",
+ fdt_get_name(blob, target, NULL),
+ disp->phandle_cells, cells_size);
+ return -1;
+ }
+ phandle_args = fdt32_to_cpu(*(const fdt32_t *)cells_prop);
+ }
+ ret = fdt_get_path(blob, target, buf, sizeof(buf));
+ if (ret < 0) {
+ report_error("Could not get full path", ret);
+ return -1;
+ }
+ printf("%s", buf);
+
+ return phandle_args;
+}
+
/**
* Shows a list of cells in the requested format
*
@@ -60,12 +121,15 @@ static void report_error(const char *where, int err)
* @param data Data to display
* @param len Maximum length of buffer
* @param size Data size to use for display (e.g. 4 for 32-bit)
+ * @param blob Device tree blob (for looking up phandles)
* @return 0 if ok, -1 on error
*/
static int show_cell_list(struct display_info *disp, const char *data, int len,
- int size)
+ int size, const void *blob)
{
const uint8_t *p = (const uint8_t *)data;
+ int phandle_start = 0; /* expecting a phandle pointer next */
+ int phandle_args = 0; /* numnber of phandle args left to process */
char fmt[3];
int value;
int i;
@@ -73,12 +137,33 @@ static int show_cell_list(struct display_info *disp, const char *data, int len,
fmt[0] = '%';
fmt[1] = disp->type ? disp->type : 'd';
fmt[2] = '\0';
+ if (disp->decode_phandles) {
+ if (size != 4) {
+ fprintf(stderr, "Decoding phandles requires an output "
+ "size of 4 bytes\n");
+ return -1;
+ }
+ phandle_start = 1;
+ }
for (i = 0; i < len; i += size, p += size) {
if (i)
printf(" ");
value = size == 4 ? fdt32_to_cpu(*(const fdt32_t *)p) :
size == 2 ? (*p << 8) | p[1] : *p;
- printf(fmt, value);
+ if (phandle_start && phandle_args <= 0) {
+ phandle_args = decode_phandle_target(disp, value, blob);
+ if (phandle_args < 0)
+ return phandle_args;
+ } else {
+ printf(fmt, value);
+ if (phandle_args > 0)
+ phandle_args--;
+ }
+ }
+ if (phandle_args > 0) {
+ fprintf(stderr, "Not enough data: %d more arg(s) expected",
+ phandle_args);
+ return -1;
}
return 0;
@@ -93,9 +178,11 @@ static int show_cell_list(struct display_info *disp, const char *data, int len,
* @param disp Display information / options
* @param data Data to display
* @param len Maximum length of buffer
- * @return 0 if ok, -1 if data does not match format
+ * @param blob Device tree blob (for looking up phandles)
+ * @return 0 if ok, -1 on error
*/
-static int show_data(struct display_info *disp, const char *data, int len)
+static int show_data(struct display_info *disp, const char *data, int len,
+ const void *blob)
{
int size;
const char *s;
@@ -128,7 +215,7 @@ static int show_data(struct display_info *disp, const char *data, int len)
return -1;
}
- return show_cell_list(disp, data, len, size);
+ return show_cell_list(disp, data, len, size, blob);
}
/**
@@ -239,7 +326,7 @@ static int show_data_for_item(const void *blob, struct display_info *disp,
assert(property);
value = fdt_getprop(blob, node, property, &len);
if (value) {
- if (show_data(disp, value, len))
+ if (show_data(disp, value, len, blob))
err = -1;
else
printf("\n");
@@ -308,12 +395,14 @@ static const char usage_synopsis[] =
"\n"
"Each value is printed on a new line.\n"
USAGE_TYPE_MSG;
-static const char usage_short_opts[] = "t:pld:" USAGE_COMMON_SHORT_OPTS;
+static const char usage_short_opts[] = "t:pld:Pc:" USAGE_COMMON_SHORT_OPTS;
static struct option const usage_long_opts[] = {
{"type", a_argument, NULL, 't'},
{"properties", no_argument, NULL, 'p'},
{"list", no_argument, NULL, 'l'},
{"default", a_argument, NULL, 'd'},
+ {"decode-phandles", no_argument, NULL, 'P'},
+ {"cells", a_argument, NULL, 'c'},
USAGE_COMMON_LONG_OPTS,
};
static const char * const usage_opts_help[] = {
@@ -321,6 +410,9 @@ static const char * const usage_opts_help[] = {
"List properties for each node",
"List subnodes for each node",
"Default value to display when the property is missing",
+ "Decode phandles to show the target node and (with -c) args (this only "
+ "supports some common cases)",
+ "Cells property in phandle target (e.g. 'gpio' for '#gpio-cells') ",
USAGE_COMMON_OPTS_HELP
};
@@ -358,6 +450,20 @@ int main(int argc, char *argv[])
case 'd':
disp.default_val = optarg;
break;
+
+ case 'P':
+ disp.decode_phandles = 1;
+ break;
+
+ case 'c':
+ disp.phandle_cells = malloc(strlen(optarg) +
+ strlen("#-cells"));
+ if (!disp.phandle_cells) {
+ fprintf(stderr, "Out of memory\n");
+ return 1;
+ }
+ sprintf(disp.phandle_cells, "#%s-cells", optarg);
+ break;
}
}
diff --git a/tests/label01.dts b/tests/label01.dts
index a895803..e7f3044 100644
--- a/tests/label01.dts
+++ b/tests/label01.dts
@@ -59,5 +59,36 @@ memrsv2: /memreserve/ 0x2000000000000000 0x0100000000000000;
linux,platform = <0x600>;
};
+ phandle-test {
+ first = <&target_a 10 20>;
+ both = <&target_a 30 40 &target_b 50 &target_a 60 70>;
+ third = <&target_c &target_c>;
+ all = <&target_a 30 40 &target_b 50 &target_c &target_a 60 70>;
+ too-few-args = <&target_a 80>;
+ invalid-size = [01];
+ invalid-target = <&target_d>;
+ invalid-phandle = <1000 1 2 3 4>;
+ };
+
+ target_a: target@0 {
+ reg = <0 0 0 0>;
+ #gpio-cells = <2>;
+ };
+
+ target_b: target@1 {
+ reg = <1 0 0 0>;
+ #gpio-cells = <1>;
+ };
+
+ target_c: target@2 {
+ reg = <2 0 0 0>;
+ #gpio-cells = <0>;
+ };
+
+ target_d: target@3 {
+ reg = <3 0 0 0>;
+ #gpio-cells = [01]; /* invalid cell value */
+ };
+
};
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index 670eeca..83401cc 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -757,6 +757,25 @@ fdtget_tests () {
run_fdtget_test "<the dead silence>" -tx \
-d "<the dead silence>" $dtb /randomnode doctor-who
run_fdtget_test "<blink>" -tx -d "<blink>" $dtb /memory doctor-who
+
+ # Test decoding of phandles
+ run_fdtget_test "/target@0 10 20" -P -c "gpio" $dtb /phandle-test first
+ run_fdtget_test "/target@0 30 40 /target@1 50 /target@0 60 70" \
+ -P -c "gpio" $dtb /phandle-test both
+ run_fdtget_test "/target@2 /target@2" -P -c "gpio" $dtb /phandle-test third
+ run_fdtget_test "/target@0 30 40 /target@1 50 /target@2 /target@0 60 70" \
+ -P -c "gpio" $dtb /phandle-test all
+
+ # Without the -c parameter we cannot decode some phandles.
+ run_wrap_error_test $DTGET --decode-phandles $dtb /phandle-test first
+ run_wrap_error_test $DTGET -P $dtb /phandle-test both
+ run_wrap_error_test $DTGET -P $dtb /phandle-test all
+ run_wrap_error_test $DTGET -P -c wrong $dtb /phandle-test all
+
+ run_wrap_error_test $DTGET -P -c gpio $dtb /phandle-test too-few-args
+ run_wrap_error_test $DTGET -P -c gpio $dtb /phandle-test invalid-size
+ run_wrap_error_test $DTGET -P -c gpio $dtb /phandle-test invalid-target
+ run_wrap_error_test $DTGET -P $dtb /phandle-test invalid-phandle
}
fdtput_tests () {
--
2.17.0.441.gb46fe60e1d-goog
--
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