mirror of https://gitee.com/openkylin/linux.git
98 lines
2.4 KiB
C
98 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/string.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include <asm/prom.h>
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#include "of_helpers.h"
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/**
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* pseries_of_derive_parent - basically like dirname(1)
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* @path: the full_name of a node to be added to the tree
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*
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* Returns the node which should be the parent of the node
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* described by path. E.g., for path = "/foo/bar", returns
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* the node with full_name = "/foo".
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*/
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struct device_node *pseries_of_derive_parent(const char *path)
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{
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struct device_node *parent;
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char *parent_path = "/";
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const char *tail;
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/* We do not want the trailing '/' character */
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tail = kbasename(path) - 1;
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/* reject if path is "/" */
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if (!strcmp(path, "/"))
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return ERR_PTR(-EINVAL);
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if (tail > path) {
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parent_path = kstrndup(path, tail - path, GFP_KERNEL);
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if (!parent_path)
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return ERR_PTR(-ENOMEM);
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}
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parent = of_find_node_by_path(parent_path);
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if (strcmp(parent_path, "/"))
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kfree(parent_path);
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return parent ? parent : ERR_PTR(-EINVAL);
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}
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/* Helper Routines to convert between drc_index to cpu numbers */
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int of_read_drc_info_cell(struct property **prop, const __be32 **curval,
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struct of_drc_info *data)
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{
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const char *p = (char *)(*curval);
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const __be32 *p2;
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if (!data)
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return -EINVAL;
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/* Get drc-type:encode-string */
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data->drc_type = (char *)p;
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p = of_prop_next_string(*prop, p);
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if (!p)
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return -EINVAL;
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/* Get drc-name-prefix:encode-string */
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data->drc_name_prefix = (char *)p;
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p = of_prop_next_string(*prop, p);
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if (!p)
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return -EINVAL;
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/* Get drc-index-start:encode-int */
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p2 = (const __be32 *)p;
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data->drc_index_start = be32_to_cpu(*p2);
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/* Get drc-name-suffix-start:encode-int */
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p2 = of_prop_next_u32(*prop, p2, &data->drc_name_suffix_start);
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if (!p2)
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return -EINVAL;
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/* Get number-sequential-elements:encode-int */
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p2 = of_prop_next_u32(*prop, p2, &data->num_sequential_elems);
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if (!p2)
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return -EINVAL;
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/* Get sequential-increment:encode-int */
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p2 = of_prop_next_u32(*prop, p2, &data->sequential_inc);
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if (!p2)
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return -EINVAL;
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/* Get drc-power-domain:encode-int */
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p2 = of_prop_next_u32(*prop, p2, &data->drc_power_domain);
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if (!p2)
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return -EINVAL;
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/* Should now know end of current entry */
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(*curval) = (void *)(++p2);
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data->last_drc_index = data->drc_index_start +
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((data->num_sequential_elems - 1) * data->sequential_inc);
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return 0;
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}
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EXPORT_SYMBOL(of_read_drc_info_cell);
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