drivers/video/of_display_timing.c

   1 /*
   2  * OF helpers for parsing display timings
   3  *
   4  * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
   5  *
   6  * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de>
   7  *
   8  * This file is released under the GPLv2
   9  */
  10 #include <linux/export.h>
  11 #include <linux/of.h>
  12 #include <linux/slab.h>
  13 #include <video/display_timing.h>
  14 #include <video/of_display_timing.h>
  15
  16 /**
  17  * parse_timing_property - parse timing_entry from device_node
  18  * @np: device_node with the property
  19  * @name: name of the property
  20  * @result: will be set to the return value
  21  *
  22  * DESCRIPTION:
  23  * Every display_timing can be specified with either just the typical value or
  24  * a range consisting of min/typ/max. This function helps handling this
  25  **/
  26 static int parse_timing_property(const struct device_node *np, const char *name,
  27                           struct timing_entry *result)
  28 {
  29         struct property *prop;
  30         int length, cells, ret;
  31
  32         prop = of_find_property(np, name, &length);
  33         if (!prop) {
  34                 pr_err("%s: could not find property %s\n",
  35                         of_node_full_name(np), name);
  36                 return -EINVAL;
  37         }
  38
  39         cells = length / sizeof(u32);
  40         if (cells == 1) {
  41                 ret = of_property_read_u32(np, name, &result->typ);
  42                 result->min = result->typ;
  43                 result->max = result->typ;
  44         } else if (cells == 3) {
  45                 ret = of_property_read_u32_array(np, name, &result->min, cells);
  46         } else {
  47                 pr_err("%s: illegal timing specification in %s\n",
  48                         of_node_full_name(np), name);
  49                 return -EINVAL;
  50         }
  51
  52         return ret;
  53 }
  54
  55 /**
  56  * of_parse_display_timing - parse display_timing entry from device_node
  57  * @np: device_node with the properties
  58  **/
  59 static int of_parse_display_timing(const struct device_node *np,
  60                 struct display_timing *dt)
  61 {
  62         u32 val = 0;
  63         int ret = 0;
  64 #if defined(CONFIG_FB_ROCKCHIP)
  65         struct property *prop;
  66         int length;
  67 #endif
  68
  69         memset(dt, 0, sizeof(*dt));
  70
  71         ret |= parse_timing_property(np, "hback-porch", &dt->hback_porch);
  72         ret |= parse_timing_property(np, "hfront-porch", &dt->hfront_porch);
  73         ret |= parse_timing_property(np, "hactive", &dt->hactive);
  74         ret |= parse_timing_property(np, "hsync-len", &dt->hsync_len);
  75         ret |= parse_timing_property(np, "vback-porch", &dt->vback_porch);
  76         ret |= parse_timing_property(np, "vfront-porch", &dt->vfront_porch);
  77         ret |= parse_timing_property(np, "vactive", &dt->vactive);
  78         ret |= parse_timing_property(np, "vsync-len", &dt->vsync_len);
  79         ret |= parse_timing_property(np, "clock-frequency", &dt->pixelclock);
  80
  81         dt->flags = 0;
  82         if (!of_property_read_u32(np, "vsync-active", &val))
  83                 dt->flags |= val ? DISPLAY_FLAGS_VSYNC_HIGH :
  84                                 DISPLAY_FLAGS_VSYNC_LOW;
  85         if (!of_property_read_u32(np, "hsync-active", &val))
  86                 dt->flags |= val ? DISPLAY_FLAGS_HSYNC_HIGH :
  87                                 DISPLAY_FLAGS_HSYNC_LOW;
  88         if (!of_property_read_u32(np, "de-active", &val))
  89                 dt->flags |= val ? DISPLAY_FLAGS_DE_HIGH :
  90                                 DISPLAY_FLAGS_DE_LOW;
  91         if (!of_property_read_u32(np, "pixelclk-active", &val))
  92                 dt->flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE :
  93                                 DISPLAY_FLAGS_PIXDATA_NEGEDGE;
  94
  95         if (of_property_read_bool(np, "interlaced"))
  96                 dt->flags |= DISPLAY_FLAGS_INTERLACED;
  97         if (of_property_read_bool(np, "doublescan"))
  98                 dt->flags |= DISPLAY_FLAGS_DOUBLESCAN;
  99         if (of_property_read_bool(np, "doubleclk"))
 100                 dt->flags |= DISPLAY_FLAGS_DOUBLECLK;
 101 #if defined(CONFIG_FB_ROCKCHIP)
 102         if (!of_property_read_u32(np, "swap-rg", &val))
 103                 dt->flags |= val ? DISPLAY_FLAGS_SWAP_RG : 0;
 104         if (!of_property_read_u32(np, "swap-gb", &val))
 105                 dt->flags |= val ? DISPLAY_FLAGS_SWAP_GB : 0;
 106         if (!of_property_read_u32(np, "swap-rb", &val))
 107                 dt->flags |= val ? DISPLAY_FLAGS_SWAP_RB : 0;
 108         if (!of_property_read_u32(np, "screen-type", &val))
 109                 dt->screen_type = val;
 110         if (!of_property_read_u32(np, "lvds-format", &val))
 111                 dt->lvds_format = val;
 112         if (!of_property_read_u32(np, "out-face", &val))
 113                 dt->face = val;
 114         if (!of_property_read_u32(np, "color-mode", &val))
 115                 dt->color_mode = val;
 116         prop = of_find_property(np, "dsp-lut", &length);
 117         if (prop) {
 118                 dt->dsp_lut = kzalloc(length, GFP_KERNEL);
 119                 if (dt->dsp_lut)
 120                         ret = of_property_read_u32_array(np,
 121                                 "dsp-lut", dt->dsp_lut, length >> 2);
 122         }
 123         prop = of_find_property(np, "cabc-lut", &length);
 124         if (prop) {
 125                 dt->cabc_lut = kzalloc(length, GFP_KERNEL);
 126                 if (dt->cabc_lut)
 127                         ret = of_property_read_u32_array(np,
 128                                                          "cabc-lut",
 129                                                          dt->cabc_lut,
 130                                                          length >> 2);
 131         }
 132
 133         prop = of_find_property(np, "cabc-gamma-base", &length);
 134         if (prop) {
 135                 dt->cabc_gamma_base = kzalloc(length, GFP_KERNEL);
 136                 if (dt->cabc_gamma_base)
 137                         ret = of_property_read_u32_array(np,
 138                                                          "cabc-gamma-base",
 139                                                          dt->cabc_gamma_base,
 140                                                          length >> 2);
 141         }
 142 #endif
 143
 144         if (ret) {
 145                 pr_err("%s: error reading timing properties\n",
 146                         of_node_full_name(np));
 147                 return -EINVAL;
 148         }
 149
 150         return 0;
 151 }
 152
 153 /**
 154  * of_get_display_timing - parse a display_timing entry
 155  * @np: device_node with the timing subnode
 156  * @name: name of the timing node
 157  * @dt: display_timing struct to fill
 158  **/
 159 int of_get_display_timing(struct device_node *np, const char *name,
 160                 struct display_timing *dt)
 161 {
 162         struct device_node *timing_np;
 163
 164         if (!np)
 165                 return -EINVAL;
 166
 167         timing_np = of_get_child_by_name(np, name);
 168         if (!timing_np) {
 169                 pr_err("%s: could not find node '%s'\n",
 170                         of_node_full_name(np), name);
 171                 return -ENOENT;
 172         }
 173
 174         return of_parse_display_timing(timing_np, dt);
 175 }
 176 EXPORT_SYMBOL_GPL(of_get_display_timing);
 177
 178 /**
 179  * of_get_display_timings - parse all display_timing entries from a device_node
 180  * @np: device_node with the subnodes
 181  **/
 182 struct display_timings *of_get_display_timings(struct device_node *np)
 183 {
 184         struct device_node *timings_np;
 185         struct device_node *entry;
 186         struct device_node *native_mode;
 187         struct display_timings *disp;
 188
 189         if (!np)
 190                 return NULL;
 191
 192         timings_np = of_get_child_by_name(np, "display-timings");
 193         if (!timings_np) {
 194                 pr_err("%s: could not find display-timings node\n",
 195                         of_node_full_name(np));
 196                 return NULL;
 197         }
 198
 199         disp = kzalloc(sizeof(*disp), GFP_KERNEL);
 200         if (!disp) {
 201                 pr_err("%s: could not allocate struct disp'\n",
 202                         of_node_full_name(np));
 203                 goto dispfail;
 204         }
 205
 206         entry = of_parse_phandle(timings_np, "native-mode", 0);
 207         /* assume first child as native mode if none provided */
 208         if (!entry)
 209                 entry = of_get_next_child(timings_np, NULL);
 210         /* if there is no child, it is useless to go on */
 211         if (!entry) {
 212                 pr_err("%s: no timing specifications given\n",
 213                         of_node_full_name(np));
 214                 goto entryfail;
 215         }
 216
 217         pr_debug("%s: using %s as default timing\n",
 218                 of_node_full_name(np), entry->name);
 219
 220         native_mode = entry;
 221
 222         disp->num_timings = of_get_child_count(timings_np);
 223         if (disp->num_timings == 0) {
 224                 /* should never happen, as entry was already found above */
 225                 pr_err("%s: no timings specified\n", of_node_full_name(np));
 226                 goto entryfail;
 227         }
 228
 229         disp->timings = kzalloc(sizeof(struct display_timing *) *
 230                                 disp->num_timings, GFP_KERNEL);
 231         if (!disp->timings) {
 232                 pr_err("%s: could not allocate timings array\n",
 233                         of_node_full_name(np));
 234                 goto entryfail;
 235         }
 236
 237         disp->num_timings = 0;
 238         disp->native_mode = 0;
 239
 240         for_each_child_of_node(timings_np, entry) {
 241                 struct display_timing *dt;
 242                 int r;
 243
 244                 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
 245                 if (!dt) {
 246                         pr_err("%s: could not allocate display_timing struct\n",
 247                                         of_node_full_name(np));
 248                         goto timingfail;
 249                 }
 250
 251                 r = of_parse_display_timing(entry, dt);
 252                 if (r) {
 253                         /*
 254                          * to not encourage wrong devicetrees, fail in case of
 255                          * an error
 256                          */
 257                         pr_err("%s: error in timing %d\n",
 258                                 of_node_full_name(np), disp->num_timings + 1);
 259                         kfree(dt);
 260                         goto timingfail;
 261                 }
 262
 263                 if (native_mode == entry)
 264                         disp->native_mode = disp->num_timings;
 265
 266                 disp->timings[disp->num_timings] = dt;
 267                 disp->num_timings++;
 268         }
 269         of_node_put(timings_np);
 270         /*
 271          * native_mode points to the device_node returned by of_parse_phandle
 272          * therefore call of_node_put on it
 273          */
 274         of_node_put(native_mode);
 275
 276         pr_debug("%s: got %d timings. Using timing #%d as default\n",
 277                 of_node_full_name(np), disp->num_timings,
 278                 disp->native_mode + 1);
 279
 280         return disp;
 281
 282 timingfail:
 283         of_node_put(native_mode);
 284         display_timings_release(disp);
 285         disp = NULL;
 286 entryfail:
 287         kfree(disp);
 288 dispfail:
 289         of_node_put(timings_np);
 290         return NULL;
 291 }
 292 EXPORT_SYMBOL_GPL(of_get_display_timings);
 293
 294 /**
 295  * of_display_timings_exist - check if a display-timings node is provided
 296  * @np: device_node with the timing
 297  **/
 298 int of_display_timings_exist(struct device_node *np)
 299 {
 300         struct device_node *timings_np;
 301
 302         if (!np)
 303                 return -EINVAL;
 304
 305         timings_np = of_parse_phandle(np, "display-timings", 0);
 306         if (!timings_np)
 307                 return -EINVAL;
 308
 309         of_node_put(timings_np);
 310         return 1;
 311 }
 312 EXPORT_SYMBOL_GPL(of_display_timings_exist);