On Fri, 16 Feb 2024 at 02:22, Caleb Connolly caleb.connolly@linaro.org wrote:
With just a few basic rules, we can generate the $fdtfile environment variable to match the format used in Linux. This uses the root compatible property inside u-boot, with specific handling for the Dragonboard845c which is a special case, and for the qrb robotics boards.
This is known to work on supported platforms, and lets us avoid having a big lookup table.
Reviewed-by: Neil Armstrong neil.armstrong@linaro.org Signed-off-by: Caleb Connolly caleb.connolly@linaro.org
arch/arm/mach-snapdragon/board.c | 101 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+)
Reviewed-by: Sumit Garg sumit.garg@linaro.org
-Sumit
diff --git a/arch/arm/mach-snapdragon/board.c b/arch/arm/mach-snapdragon/board.c index f445bed3af00..5a859aabd5c4 100644 --- a/arch/arm/mach-snapdragon/board.c +++ b/arch/arm/mach-snapdragon/board.c @@ -160,6 +160,106 @@ int board_init(void) return 0; }
+/* Sets up the "board", and "soc" environment variables as well as constructing the devicetree
- path, with a few quirks to handle non-standard dtb filenames. This is not meant to be a
- comprehensive solution to automatically picking the DTB, but aims to be correct for the
- majority case. For most devices it should be possible to make this algorithm work by
- adjusting the root compatible property in the U-Boot DTS. Handling devices with multiple
- variants that are all supported by a single U-Boot image will require implementing device-
- specific detection.
- */
+static void configure_env(void) +{
const char *first_compat, *last_compat;char *tmp;char buf[32] = { 0 };/** Most DTB filenames follow the scheme: qcom/<soc>-[vendor]-<board>.dtb* The vendor is skipped when it's a Qualcomm reference board, or the* db845c.*/char dt_path[64] = { 0 };int compat_count, ret;ofnode root;root = ofnode_root();/* This is almost always 2, but be explicit that we want the first and last compatibles* not the first and second.*/compat_count = ofnode_read_string_count(root, "compatible");if (compat_count < 2) {log_warning("%s: only one root compatible bailing!\n", __func__);return;}/* The most specific device compatible (e.g. "thundercomm,db845c") */ret = ofnode_read_string_index(root, "compatible", 0, &first_compat);if (ret < 0) {log_warning("Can't read first compatible\n");return;}/* The last compatible is always the SoC compatible */ret = ofnode_read_string_index(root, "compatible", compat_count - 1, &last_compat);if (ret < 0) {log_warning("Can't read second compatible\n");return;}/* Copy the second compat (e.g. "qcom,sdm845") into buf */strlcpy(buf, last_compat, sizeof(buf) - 1);tmp = buf;/* strsep() is destructive, it replaces the comma with a \0 */if (!strsep(&tmp, ",")) {log_warning("second compatible '%s' has no ','\n", buf);return;}/* tmp now points to just the "sdm845" part of the string */env_set("soc", tmp);/* Now figure out the "board" part from the first compatible */memset(buf, 0, sizeof(buf));strlcpy(buf, first_compat, sizeof(buf) - 1);tmp = buf;/* The Qualcomm reference boards (RBx, HDK, etc) */if (!strncmp("qcom", buf, strlen("qcom"))) {/** They all have the first compatible as "qcom,<soc>-<board>"* (e.g. "qcom,qrb5165-rb5"). We extract just the part after* the dash.*/if (!strsep(&tmp, "-")) {log_warning("compatible '%s' has no '-'\n", buf);return;}/* tmp is now "rb5" */env_set("board", tmp);} else {if (!strsep(&tmp, ",")) {log_warning("compatible '%s' has no ','\n", buf);return;}/* for thundercomm we just want the bit after the comma (e.g. "db845c"),* for all other boards we replace the comma with a '-' and take both* (e.g. "oneplus-enchilada")*/if (!strncmp("thundercomm", buf, strlen("thundercomm"))) {env_set("board", tmp);} else {*(tmp - 1) = '-';env_set("board", buf);}}/* Now build the full path name */snprintf(dt_path, sizeof(dt_path), "qcom/%s-%s.dtb",env_get("soc"), env_get("board"));env_set("fdtfile", dt_path);+}
void __weak qcom_late_init(void) { } @@ -188,6 +288,7 @@ int board_late_init(void) if (status) log_warning("%s: Failed to set run time variables\n", __func__);
configure_env(); qcom_late_init(); return 0;-- 2.43.1