linux/drivers/gpu/drm/omapdrm/dss/omapdss-boot-init.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/
   4 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
   5 */
   6
   7/*
   8 * As omapdss panel drivers are omapdss specific, but we want to define the
   9 * DT-data in generic manner, we convert the compatible strings of the panel and
  10 * encoder nodes from "panel-foo" to "omapdss,panel-foo". This way we can have
  11 * both correct DT data and omapdss specific drivers.
  12 *
  13 * When we get generic panel drivers to the kernel, this file will be removed.
  14 */
  15
  16#include <linux/kernel.h>
  17#include <linux/of.h>
  18#include <linux/of_graph.h>
  19#include <linux/slab.h>
  20#include <linux/list.h>
  21
  22static struct list_head dss_conv_list __initdata;
  23
  24static const char prefix[] __initconst = "omapdss,";
  25
  26struct dss_conv_node {
  27        struct list_head list;
  28        struct device_node *node;
  29        bool root;
  30};
  31
  32static int __init omapdss_count_strings(const struct property *prop)
  33{
  34        const char *p = prop->value;
  35        int l = 0, total = 0;
  36        int i;
  37
  38        for (i = 0; total < prop->length; total += l, p += l, i++)
  39                l = strlen(p) + 1;
  40
  41        return i;
  42}
  43
  44static void __init omapdss_update_prop(struct device_node *node, char *compat,
  45        int len)
  46{
  47        struct property *prop;
  48
  49        prop = kzalloc(sizeof(*prop), GFP_KERNEL);
  50        if (!prop)
  51                return;
  52
  53        prop->name = "compatible";
  54        prop->value = compat;
  55        prop->length = len;
  56
  57        of_update_property(node, prop);
  58}
  59
  60static void __init omapdss_prefix_strcpy(char *dst, int dst_len,
  61        const char *src, int src_len)
  62{
  63        size_t total = 0;
  64
  65        while (total < src_len) {
  66                size_t l = strlen(src) + 1;
  67
  68                strcpy(dst, prefix);
  69                dst += strlen(prefix);
  70
  71                strcpy(dst, src);
  72                dst += l;
  73
  74                src += l;
  75                total += l;
  76        }
  77}
  78
  79/* prepend compatible property strings with "omapdss," */
  80static void __init omapdss_omapify_node(struct device_node *node)
  81{
  82        struct property *prop;
  83        char *new_compat;
  84        int num_strs;
  85        int new_len;
  86
  87        prop = of_find_property(node, "compatible", NULL);
  88
  89        if (!prop || !prop->value)
  90                return;
  91
  92        if (strnlen(prop->value, prop->length) >= prop->length)
  93                return;
  94
  95        /* is it already prefixed? */
  96        if (strncmp(prefix, prop->value, strlen(prefix)) == 0)
  97                return;
  98
  99        num_strs = omapdss_count_strings(prop);
 100
 101        new_len = prop->length + strlen(prefix) * num_strs;
 102        new_compat = kmalloc(new_len, GFP_KERNEL);
 103
 104        omapdss_prefix_strcpy(new_compat, new_len, prop->value, prop->length);
 105
 106        omapdss_update_prop(node, new_compat, new_len);
 107}
 108
 109static void __init omapdss_add_to_list(struct device_node *node, bool root)
 110{
 111        struct dss_conv_node *n = kmalloc(sizeof(*n), GFP_KERNEL);
 112        if (n) {
 113                n->node = node;
 114                n->root = root;
 115                list_add(&n->list, &dss_conv_list);
 116        }
 117}
 118
 119static bool __init omapdss_list_contains(const struct device_node *node)
 120{
 121        struct dss_conv_node *n;
 122
 123        list_for_each_entry(n, &dss_conv_list, list) {
 124                if (n->node == node)
 125                        return true;
 126        }
 127
 128        return false;
 129}
 130
 131static void __init omapdss_walk_device(struct device_node *node, bool root)
 132{
 133        struct device_node *n;
 134
 135        omapdss_add_to_list(node, root);
 136
 137        /*
 138         * of_graph_get_remote_port_parent() prints an error if there is no
 139         * port/ports node. To avoid that, check first that there's the node.
 140         */
 141        n = of_get_child_by_name(node, "ports");
 142        if (!n)
 143                n = of_get_child_by_name(node, "port");
 144        if (!n)
 145                return;
 146
 147        of_node_put(n);
 148
 149        n = NULL;
 150        while ((n = of_graph_get_next_endpoint(node, n)) != NULL) {
 151                struct device_node *pn;
 152
 153                pn = of_graph_get_remote_port_parent(n);
 154
 155                if (!pn)
 156                        continue;
 157
 158                if (!of_device_is_available(pn) || omapdss_list_contains(pn)) {
 159                        of_node_put(pn);
 160                        continue;
 161                }
 162
 163                omapdss_walk_device(pn, false);
 164        }
 165}
 166
 167static const struct of_device_id omapdss_of_match[] __initconst = {
 168        { .compatible = "ti,omap2-dss", },
 169        { .compatible = "ti,omap3-dss", },
 170        { .compatible = "ti,omap4-dss", },
 171        { .compatible = "ti,omap5-dss", },
 172        { .compatible = "ti,dra7-dss", },
 173        {},
 174};
 175
 176static const struct of_device_id omapdss_of_fixups_whitelist[] __initconst = {
 177        { .compatible = "composite-video-connector" },
 178        { .compatible = "hdmi-connector" },
 179        { .compatible = "panel-dsi-cm" },
 180        { .compatible = "svideo-connector" },
 181        { .compatible = "ti,opa362" },
 182        { .compatible = "ti,tpd12s015" },
 183        {},
 184};
 185
 186static int __init omapdss_boot_init(void)
 187{
 188        struct device_node *dss, *child;
 189
 190        INIT_LIST_HEAD(&dss_conv_list);
 191
 192        dss = of_find_matching_node(NULL, omapdss_of_match);
 193
 194        if (dss == NULL || !of_device_is_available(dss))
 195                return 0;
 196
 197        omapdss_walk_device(dss, true);
 198
 199        for_each_available_child_of_node(dss, child) {
 200                if (!of_find_property(child, "compatible", NULL))
 201                        continue;
 202
 203                omapdss_walk_device(child, true);
 204        }
 205
 206        while (!list_empty(&dss_conv_list)) {
 207                struct dss_conv_node *n;
 208
 209                n = list_first_entry(&dss_conv_list, struct dss_conv_node,
 210                        list);
 211
 212                if (of_match_node(omapdss_of_fixups_whitelist, n->node))
 213                        omapdss_omapify_node(n->node);
 214
 215                list_del(&n->list);
 216                of_node_put(n->node);
 217                kfree(n);
 218        }
 219
 220        return 0;
 221}
 222
 223subsys_initcall(omapdss_boot_init);
 224