From: Thierry Reding treding@nvidia.com
The fdtdec_get_carveout() and fdtdec_set_carveout() function can be used to read a carveout from a given node or add a carveout to a given node using the standard device tree bindings (involving reserved-memory nodes and the memory-region property).
Reviewed-by: Simon Glass sjg@chromium.org Signed-off-by: Thierry Reding treding@nvidia.com --- Changes in v2: - use debug() instead of printf() to save code size - fix carveout size computations, was off by one - use fdtdec_get_addr_size_auto_noparent()
include/fdtdec.h | 39 ++++++++++++++++++++++ lib/fdtdec.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 126 insertions(+)
diff --git a/include/fdtdec.h b/include/fdtdec.h index 5c23a9e5f104..14fff6806df2 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -1021,6 +1021,45 @@ int fdtdec_add_reserved_memory(void *blob, const char *basename, const struct fdt_memory *carveout, uint32_t *phandlep);
+/** + * fdtdec_get_carveout() - reads a carveout from an FDT + * + * Reads information about a carveout region from an FDT. The carveout is a + * referenced by its phandle that is read from a given property in a given + * node. + * + * @param blob FDT blob + * @param node name of a node + * @param name name of the property in the given node that contains + * the phandle for the carveout + * @param index index of the phandle for which to read the carveout + * @param carveout return location for the carveout information + * @return 0 on success or a negative error code on failure + */ +int fdtdec_get_carveout(const void *blob, const char *node, const char *name, + unsigned int index, struct fdt_memory *carveout); + +/** + * fdtdec_set_carveout() - sets a carveout region for a given node + * + * Sets a carveout region for a given node. If a reserved-memory node already + * exists for the carveout, the phandle for that node will be reused. If no + * such node exists, a new one will be created and a phandle to it stored in + * a specified property of the given node. + * + * @param blob FDT blob + * @param node name of the node to add the carveout to + * @param prop_name name of the property in which to store the phandle of + * the carveout + * @param index index of the phandle to store + * @param name base name of the reserved-memory node to create + * @param carveout information about the carveout to add + * @return 0 on success or a negative error code on failure + */ +int fdtdec_set_carveout(void *blob, const char *node, const char *prop_name, + unsigned int index, const char *name, + const struct fdt_memory *carveout); + /** * Set up the device tree ready for use */ diff --git a/lib/fdtdec.c b/lib/fdtdec.c index bef331df9a08..8ab41682104e 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -1409,6 +1409,93 @@ int fdtdec_add_reserved_memory(void *blob, const char *basename, return 0; }
+int fdtdec_get_carveout(const void *blob, const char *node, const char *name, + unsigned int index, struct fdt_memory *carveout) +{ + const fdt32_t *prop; + uint32_t phandle; + int offset, len; + fdt_size_t size; + + offset = fdt_path_offset(blob, node); + if (offset < 0) + return offset; + + prop = fdt_getprop(blob, offset, name, &len); + if (!prop) { + debug("failed to get %s for %s\n", name, node); + return -FDT_ERR_NOTFOUND; + } + + if ((len % sizeof(phandle)) != 0) { + debug("invalid phandle property\n"); + return -FDT_ERR_BADPHANDLE; + } + + if (len < (sizeof(phandle) * (index + 1))) { + debug("invalid phandle index\n"); + return -FDT_ERR_BADPHANDLE; + } + + phandle = fdt32_to_cpu(prop[index]); + + offset = fdt_node_offset_by_phandle(blob, phandle); + if (offset < 0) { + debug("failed to find node for phandle %u\n", phandle); + return offset; + } + + carveout->start = fdtdec_get_addr_size_auto_noparent(blob, offset, + "reg", 0, &size, + true); + if (carveout->start == FDT_ADDR_T_NONE) { + debug("failed to read address/size from "reg" property\n"); + return -FDT_ERR_NOTFOUND; + } + + carveout->end = carveout->start + size - 1; + + return 0; +} + +int fdtdec_set_carveout(void *blob, const char *node, const char *prop_name, + unsigned int index, const char *name, + const struct fdt_memory *carveout) +{ + uint32_t phandle; + int err, offset; + fdt32_t value; + + /* XXX implement support for multiple phandles */ + if (index > 0) { + debug("invalid index %u\n", index); + return -FDT_ERR_BADOFFSET; + } + + err = fdtdec_add_reserved_memory(blob, name, carveout, &phandle); + if (err < 0) { + debug("failed to add reserved memory: %d\n", err); + return err; + } + + offset = fdt_path_offset(blob, node); + if (offset < 0) { + debug("failed to find offset for node %s: %d\n", node, offset); + return offset; + } + + value = cpu_to_fdt32(phandle); + + err = fdt_setprop(blob, offset, prop_name, &value, sizeof(value)); + if (err < 0) { + debug("failed to set %s property for node %s: %d\n", prop_name, + node, err); + return err; + } + + return 0; +} + int fdtdec_setup(void) { #if CONFIG_IS_ENABLED(OF_CONTROL)