1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/string.h> 3 #include <linux/err.h> 4 #include <linux/slab.h> 5 #include <linux/of.h> 6 #include <asm/prom.h> 7 8 #include "of_helpers.h" 9 10 /** 11 * pseries_of_derive_parent - basically like dirname(1) 12 * @path: the full_name of a node to be added to the tree 13 * 14 * Returns the node which should be the parent of the node 15 * described by path. E.g., for path = "/foo/bar", returns 16 * the node with full_name = "/foo". 17 */ 18 struct device_node *pseries_of_derive_parent(const char *path) 19 { 20 struct device_node *parent; 21 char *parent_path = "/"; 22 const char *tail; 23 24 /* We do not want the trailing '/' character */ 25 tail = kbasename(path) - 1; 26 27 /* reject if path is "/" */ 28 if (!strcmp(path, "/")) 29 return ERR_PTR(-EINVAL); 30 31 if (tail > path) { 32 parent_path = kstrndup(path, tail - path, GFP_KERNEL); 33 if (!parent_path) 34 return ERR_PTR(-ENOMEM); 35 } 36 parent = of_find_node_by_path(parent_path); 37 if (strcmp(parent_path, "/")) 38 kfree(parent_path); 39 return parent ? parent : ERR_PTR(-EINVAL); 40 } 41 42 43 /* Helper Routines to convert between drc_index to cpu numbers */ 44 45 int of_read_drc_info_cell(struct property **prop, const __be32 **curval, 46 struct of_drc_info *data) 47 { 48 const char *p = (char *)(*curval); 49 const __be32 *p2; 50 51 if (!data) 52 return -EINVAL; 53 54 /* Get drc-type:encode-string */ 55 data->drc_type = (char *)p; 56 p = of_prop_next_string(*prop, p); 57 if (!p) 58 return -EINVAL; 59 60 /* Get drc-name-prefix:encode-string */ 61 data->drc_name_prefix = (char *)p; 62 p = of_prop_next_string(*prop, p); 63 if (!p) 64 return -EINVAL; 65 66 /* Get drc-index-start:encode-int */ 67 p2 = (const __be32 *)p; 68 data->drc_index_start = be32_to_cpu(*p2); 69 70 /* Get drc-name-suffix-start:encode-int */ 71 p2 = of_prop_next_u32(*prop, p2, &data->drc_name_suffix_start); 72 if (!p2) 73 return -EINVAL; 74 75 /* Get number-sequential-elements:encode-int */ 76 p2 = of_prop_next_u32(*prop, p2, &data->num_sequential_elems); 77 if (!p2) 78 return -EINVAL; 79 80 /* Get sequential-increment:encode-int */ 81 p2 = of_prop_next_u32(*prop, p2, &data->sequential_inc); 82 if (!p2) 83 return -EINVAL; 84 85 /* Get drc-power-domain:encode-int */ 86 p2 = of_prop_next_u32(*prop, p2, &data->drc_power_domain); 87 if (!p2) 88 return -EINVAL; 89 90 /* Should now know end of current entry */ 91 (*curval) = (void *)(++p2); 92 data->last_drc_index = data->drc_index_start + 93 ((data->num_sequential_elems - 1) * data->sequential_inc); 94 95 return 0; 96 } 97 EXPORT_SYMBOL(of_read_drc_info_cell); 98