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

   1 /*
   2  * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/
   3  * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * As omapdss panel drivers are omapdss specific, but we want to define the
  20  * DT-data in generic manner, we convert the compatible strings of the panel and
  21  * encoder nodes from "panel-foo" to "omapdss,panel-foo". This way we can have
  22  * both correct DT data and omapdss specific drivers.
  23  *
  24  * When we get generic panel drivers to the kernel, this file will be removed.
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/of.h>
  29 #include <linux/of_graph.h>
  30 #include <linux/slab.h>
  31 #include <linux/list.h>
  32
  33 static struct list_head dss_conv_list __initdata;
  34
  35 static const char prefix[] __initconst = "omapdss,";
  36
  37 struct dss_conv_node {
  38         struct list_head list;
  39         struct device_node *node;
  40         bool root;
  41 };
  42
  43 static int __init omapdss_count_strings(const struct property *prop)
  44 {
  45         const char *p = prop->value;
  46         int l = 0, total = 0;
  47         int i;
  48
  49         for (i = 0; total < prop->length; total += l, p += l, i++)
  50                 l = strlen(p) + 1;
  51
  52         return i;
  53 }
  54
  55 static void __init omapdss_update_prop(struct device_node *node, char *compat,
  56         int len)
  57 {
  58         struct property *prop;
  59
  60         prop = kzalloc(sizeof(*prop), GFP_KERNEL);
  61         if (!prop)
  62                 return;
  63
  64         prop->name = "compatible";
  65         prop->value = compat;
  66         prop->length = len;
  67
  68         of_update_property(node, prop);
  69 }
  70
  71 static void __init omapdss_prefix_strcpy(char *dst, int dst_len,
  72         const char *src, int src_len)
  73 {
  74         size_t total = 0;
  75
  76         while (total < src_len) {
  77                 size_t l = strlen(src) + 1;
  78
  79                 strcpy(dst, prefix);
  80                 dst += strlen(prefix);
  81
  82                 strcpy(dst, src);
  83                 dst += l;
  84
  85                 src += l;
  86                 total += l;
  87         }
  88 }
  89
  90 /* prepend compatible property strings with "omapdss," */
  91 static void __init omapdss_omapify_node(struct device_node *node)
  92 {
  93         struct property *prop;
  94         char *new_compat;
  95         int num_strs;
  96         int new_len;
  97
  98         prop = of_find_property(node, "compatible", NULL);
  99
 100         if (!prop || !prop->value)
 101                 return;
 102
 103         if (strnlen(prop->value, prop->length) >= prop->length)
 104                 return;
 105
 106         /* is it already prefixed? */
 107         if (strncmp(prefix, prop->value, strlen(prefix)) == 0)
 108                 return;
 109
 110         num_strs = omapdss_count_strings(prop);
 111
 112         new_len = prop->length + strlen(prefix) * num_strs;
 113         new_compat = kmalloc(new_len, GFP_KERNEL);
 114
 115         omapdss_prefix_strcpy(new_compat, new_len, prop->value, prop->length);
 116
 117         omapdss_update_prop(node, new_compat, new_len);
 118 }
 119
 120 static void __init omapdss_add_to_list(struct device_node *node, bool root)
 121 {
 122         struct dss_conv_node *n = kmalloc(sizeof(*n), GFP_KERNEL);
 123         if (n) {
 124                 n->node = node;
 125                 n->root = root;
 126                 list_add(&n->list, &dss_conv_list);
 127         }
 128 }
 129
 130 static bool __init omapdss_list_contains(const struct device_node *node)
 131 {
 132         struct dss_conv_node *n;
 133
 134         list_for_each_entry(n, &dss_conv_list, list) {
 135                 if (n->node == node)
 136                         return true;
 137         }
 138
 139         return false;
 140 }
 141
 142 static void __init omapdss_walk_device(struct device_node *node, bool root)
 143 {
 144         struct device_node *n;
 145
 146         omapdss_add_to_list(node, root);
 147
 148         /*
 149          * of_graph_get_remote_port_parent() prints an error if there is no
 150          * port/ports node. To avoid that, check first that there's the node.
 151          */
 152         n = of_get_child_by_name(node, "ports");
 153         if (!n)
 154                 n = of_get_child_by_name(node, "port");
 155         if (!n)
 156                 return;
 157
 158         of_node_put(n);
 159
 160         n = NULL;
 161         while ((n = of_graph_get_next_endpoint(node, n)) != NULL) {
 162                 struct device_node *pn;
 163
 164                 pn = of_graph_get_remote_port_parent(n);
 165
 166                 if (!pn)
 167                         continue;
 168
 169                 if (!of_device_is_available(pn) || omapdss_list_contains(pn)) {
 170                         of_node_put(pn);
 171                         continue;
 172                 }
 173
 174                 omapdss_walk_device(pn, false);
 175         }
 176 }
 177
 178 static const struct of_device_id omapdss_of_match[] __initconst = {
 179         { .compatible = "ti,omap2-dss", },
 180         { .compatible = "ti,omap3-dss", },
 181         { .compatible = "ti,omap4-dss", },
 182         { .compatible = "ti,omap5-dss", },
 183         { .compatible = "ti,dra7-dss", },
 184         {},
 185 };
 186
 187 static int __init omapdss_boot_init(void)
 188 {
 189         struct device_node *dss, *child;
 190
 191         INIT_LIST_HEAD(&dss_conv_list);
 192
 193         dss = of_find_matching_node(NULL, omapdss_of_match);
 194
 195         if (dss == NULL || !of_device_is_available(dss))
 196                 return 0;
 197
 198         omapdss_walk_device(dss, true);
 199
 200         for_each_available_child_of_node(dss, child) {
 201                 if (!of_find_property(child, "compatible", NULL))
 202                         continue;
 203
 204                 omapdss_walk_device(child, true);
 205         }
 206
 207         while (!list_empty(&dss_conv_list)) {
 208                 struct dss_conv_node *n;
 209
 210                 n = list_first_entry(&dss_conv_list, struct dss_conv_node,
 211                         list);
 212
 213                 if (!n->root)
 214                         omapdss_omapify_node(n->node);
 215
 216                 list_del(&n->list);
 217                 of_node_put(n->node);
 218                 kfree(n);
 219         }
 220
 221         return 0;
 222 }
 223
 224 subsys_initcall(omapdss_boot_init);