diff options
| -rw-r--r-- | include/fdtdec.h | 81 | ||||
| -rw-r--r-- | lib/fdtdec.c | 87 |
2 files changed, 168 insertions, 0 deletions
diff --git a/include/fdtdec.h b/include/fdtdec.h index 9bd6a70587a..266c58271f0 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -1069,6 +1069,8 @@ int fdtdec_set_phandle(void *blob, int node, uint32_t phandle); * The phandle returned from the function call can be used to reference this * reserved memory region from other nodes. * + * See fdtdec_set_carveout() for a more elaborate example. + * * @param blob FDT blob * @param basename base name of the node to create * @param carveout information about the carveout region @@ -1080,6 +1082,85 @@ int fdtdec_add_reserved_memory(void *blob, const char *basename, 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. + * + * As an example, consider the following code snippet: + * + * const char *node = "/host1x@50000000/dc@54240000"; + * struct fdt_memory fb = { + * .start = 0x92cb3000, + * .end = 0x934b2fff, + * }; + * + * fdtdec_set_carveout(fdt, node, "memory-region", 0, "framebuffer", &fb); + * + * dc@54200000 is a display controller and was set up by the bootloader to + * scan out the framebuffer specified by "fb". This would cause the following + * reserved memory region to be added: + * + * reserved-memory { + * #address-cells = <0x00000002>; + * #size-cells = <0x00000002>; + * ranges; + * + * framebuffer@92cb3000 { + * reg = <0x00000000 0x92cb3000 0x00000000 0x00800000>; + * phandle = <0x0000004d>; + * }; + * }; + * + * A "memory-region" property will also be added to the node referenced by the + * offset parameter. + * + * host1x@50000000 { + * ... + * + * dc@54240000 { + * ... + * memory-region = <0x0000004d>; + * ... + * }; + * + * ... + * }; + * + * @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 */ int fdtdec_setup(void); diff --git a/lib/fdtdec.c b/lib/fdtdec.c index d247141f0b3..efec3c27177 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -1399,6 +1399,93 @@ 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) |