drivers/gpu/drm/omapdrm/dss/omapdss-boot-init.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2014 Texas Instruments Incorporated - https://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
  22 static struct list_head dss_conv_list __initdata;
  23
  24 static const char prefix[] __initconst = "omapdss,";
  25
  26 struct dss_conv_node {
  27         struct list_head list;
  28         struct device_node *node;
  29         bool root;
  30 };
  31
  32 static 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
  44 static 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
  60 static 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," */
  80 static 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
 109 static 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
 119 static 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
 131 static 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
 167 static 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
 176 static const struct of_device_id omapdss_of_fixups_whitelist[] __initconst = {
 177         { .compatible = "panel-dsi-cm" },
 178         {},
 179 };
 180
 181 static void __init omapdss_find_children(struct device_node *np)
 182 {
 183         struct device_node *child;
 184
 185         for_each_available_child_of_node(np, child) {
 186                 if (!of_find_property(child, "compatible", NULL))
 187                         continue;
 188
 189                 omapdss_walk_device(child, true);
 190
 191                 if (of_device_is_compatible(child, "ti,sysc"))
 192                         omapdss_find_children(child);
 193         }
 194 }
 195
 196 static int __init omapdss_boot_init(void)
 197 {
 198         struct device_node *dss;
 199
 200         INIT_LIST_HEAD(&dss_conv_list);
 201
 202         dss = of_find_matching_node(NULL, omapdss_of_match);
 203
 204         if (dss == NULL || !of_device_is_available(dss))
 205                 goto put_node;
 206
 207         omapdss_walk_device(dss, true);
 208         omapdss_find_children(dss);
 209
 210         while (!list_empty(&dss_conv_list)) {
 211                 struct dss_conv_node *n;
 212
 213                 n = list_first_entry(&dss_conv_list, struct dss_conv_node,
 214                         list);
 215
 216                 if (of_match_node(omapdss_of_fixups_whitelist, n->node))
 217                         omapdss_omapify_node(n->node);
 218
 219                 list_del(&n->list);
 220                 of_node_put(n->node);
 221                 kfree(n);
 222         }
 223
 224 put_node:
 225         of_node_put(dss);
 226         return 0;
 227 }
 228
 229 subsys_initcall(omapdss_boot_init);