1 /* 2 * Copyright (C) 2014 Texas Instruments 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 if (!new_compat) 115 return; 116 117 omapdss_prefix_strcpy(new_compat, new_len, prop->value, prop->length); 118 119 omapdss_update_prop(node, new_compat, new_len); 120 } 121 122 static void __init omapdss_add_to_list(struct device_node *node, bool root) 123 { 124 struct dss_conv_node *n = kmalloc(sizeof(struct dss_conv_node), 125 GFP_KERNEL); 126 if (n) { 127 n->node = node; 128 n->root = root; 129 list_add(&n->list, &dss_conv_list); 130 } 131 } 132 133 static bool __init omapdss_list_contains(const struct device_node *node) 134 { 135 struct dss_conv_node *n; 136 137 list_for_each_entry(n, &dss_conv_list, list) { 138 if (n->node == node) 139 return true; 140 } 141 142 return false; 143 } 144 145 static void __init omapdss_walk_device(struct device_node *node, bool root) 146 { 147 struct device_node *n; 148 149 omapdss_add_to_list(node, root); 150 151 /* 152 * of_graph_get_remote_port_parent() prints an error if there is no 153 * port/ports node. To avoid that, check first that there's the node. 154 */ 155 n = of_get_child_by_name(node, "ports"); 156 if (!n) 157 n = of_get_child_by_name(node, "port"); 158 if (!n) 159 return; 160 161 of_node_put(n); 162 163 n = NULL; 164 while ((n = of_graph_get_next_endpoint(node, n)) != NULL) { 165 struct device_node *pn; 166 167 pn = of_graph_get_remote_port_parent(n); 168 169 if (!pn) 170 continue; 171 172 if (!of_device_is_available(pn) || omapdss_list_contains(pn)) { 173 of_node_put(pn); 174 continue; 175 } 176 177 omapdss_walk_device(pn, false); 178 } 179 } 180 181 static const struct of_device_id omapdss_of_match[] __initconst = { 182 { .compatible = "ti,omap2-dss", }, 183 { .compatible = "ti,omap3-dss", }, 184 { .compatible = "ti,omap4-dss", }, 185 { .compatible = "ti,omap5-dss", }, 186 { .compatible = "ti,dra7-dss", }, 187 {}, 188 }; 189 190 static int __init omapdss_boot_init(void) 191 { 192 struct device_node *dss, *child; 193 194 INIT_LIST_HEAD(&dss_conv_list); 195 196 dss = of_find_matching_node(NULL, omapdss_of_match); 197 198 if (dss == NULL || !of_device_is_available(dss)) { 199 of_node_put(dss); 200 return 0; 201 } 202 203 omapdss_walk_device(dss, true); 204 205 for_each_available_child_of_node(dss, child) { 206 if (!of_find_property(child, "compatible", NULL)) 207 continue; 208 209 omapdss_walk_device(child, true); 210 } 211 212 while (!list_empty(&dss_conv_list)) { 213 struct dss_conv_node *n; 214 215 n = list_first_entry(&dss_conv_list, struct dss_conv_node, 216 list); 217 218 if (!n->root) 219 omapdss_omapify_node(n->node); 220 221 list_del(&n->list); 222 of_node_put(n->node); 223 kfree(n); 224 } 225 226 return 0; 227 } 228 229 subsys_initcall(omapdss_boot_init); 230