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(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_get_display_timing - parse display_timing entry from device_node
  57  * @np: device_node with the properties
  58  **/
  59 static struct display_timing *of_get_display_timing(struct device_node *np)
  60 {
  61         struct display_timing *dt;
  62         u32 val = 0;
  63         int ret = 0;
  64 #if defined(CONFIG_FB_ROCKCHIP) || defined(CONFIG_DRM_ROCKCHIP)
  65         struct property *prop;
  66         int length;
  67 #endif
  68         dt = kzalloc(sizeof(*dt), GFP_KERNEL);
  69         if (!dt) {
  70                 pr_err("%s: could not allocate display_timing struct\n",
  71                         of_node_full_name(np));
  72                 return NULL;
  73         }
  74
  75         ret |= parse_timing_property(np, "hback-porch", &dt->hback_porch);
  76         ret |= parse_timing_property(np, "hfront-porch", &dt->hfront_porch);
  77         ret |= parse_timing_property(np, "hactive", &dt->hactive);
  78         ret |= parse_timing_property(np, "hsync-len", &dt->hsync_len);
  79         ret |= parse_timing_property(np, "vback-porch", &dt->vback_porch);
  80         ret |= parse_timing_property(np, "vfront-porch", &dt->vfront_porch);
  81         ret |= parse_timing_property(np, "vactive", &dt->vactive);
  82         ret |= parse_timing_property(np, "vsync-len", &dt->vsync_len);
  83         ret |= parse_timing_property(np, "clock-frequency", &dt->pixelclock);
  84
  85         dt->flags = 0;
  86         if (!of_property_read_u32(np, "vsync-active", &val))
  87                 dt->flags |= val ? DISPLAY_FLAGS_VSYNC_HIGH :
  88                                 DISPLAY_FLAGS_VSYNC_LOW;
  89         if (!of_property_read_u32(np, "hsync-active", &val))
  90                 dt->flags |= val ? DISPLAY_FLAGS_HSYNC_HIGH :
  91                                 DISPLAY_FLAGS_HSYNC_LOW;
  92         if (!of_property_read_u32(np, "de-active", &val))
  93                 dt->flags |= val ? DISPLAY_FLAGS_DE_HIGH :
  94                                 DISPLAY_FLAGS_DE_LOW;
  95         if (!of_property_read_u32(np, "pixelclk-active", &val))
  96                 dt->flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE :
  97                                 DISPLAY_FLAGS_PIXDATA_NEGEDGE;
  98
  99         if (of_property_read_bool(np, "interlaced"))
 100                 dt->flags |= DISPLAY_FLAGS_INTERLACED;
 101         if (of_property_read_bool(np, "doublescan"))
 102                 dt->flags |= DISPLAY_FLAGS_DOUBLESCAN;
 103
 104 #if defined(CONFIG_FB_ROCKCHIP) || defined(CONFIG_DRM_ROCKCHIP)
 105         if (!of_property_read_u32(np, "swap-rg", &val))
 106                 dt->flags |= val ? DISPLAY_FLAGS_SWAP_RG : 0;
 107         if (!of_property_read_u32(np, "swap-gb", &val))
 108                 dt->flags |= val ? DISPLAY_FLAGS_SWAP_GB : 0;
 109         if (!of_property_read_u32(np, "swap-rb", &val))
 110                 dt->flags |= val ? DISPLAY_FLAGS_SWAP_RB : 0;
 111         if (!of_property_read_u32(np, "screen-type", &val))
 112                 dt->screen_type = val;
 113         if (!of_property_read_u32(np, "lvds-format", &val))
 114                 dt->lvds_format = val;
 115         if (!of_property_read_u32(np, "out-face", &val))
 116                 dt->face = val;
 117         if (!of_property_read_u32(np, "color-mode", &val))
 118                 dt->color_mode = val;
 119         prop = of_find_property(np, "dsp-lut", &length);
 120         if (prop) {
 121                 dt->dsp_lut = kzalloc(length, GFP_KERNEL);
 122                 if (dt->dsp_lut)
 123                         ret = of_property_read_u32_array(np,
 124                                 "dsp-lut",dt->dsp_lut, length >> 2);
 125         }
 126         prop = of_find_property(np, "cabc-lut", &length);
 127         if (prop) {
 128                 dt->cabc_lut = kzalloc(length, GFP_KERNEL);
 129                 if (dt->cabc_lut)
 130                         ret = of_property_read_u32_array(np,
 131                                                          "cabc-lut",
 132                                                          dt->cabc_lut,
 133                                                          length >> 2);
 134         }
 135
 136         prop = of_find_property(np, "cabc-gamma-base", &length);
 137         if (prop) {
 138                 dt->cabc_gamma_base = kzalloc(length, GFP_KERNEL);
 139                 if (dt->cabc_gamma_base)
 140                         ret = of_property_read_u32_array(np,
 141                                                          "cabc-gamma-base",
 142                                                          dt->cabc_gamma_base,
 143                                                          length >> 2);
 144         }
 145 #endif
 146
 147         if (ret) {
 148                 pr_err("%s: error reading timing properties\n",
 149                         of_node_full_name(np));
 150                 kfree(dt);
 151                 return NULL;
 152         }
 153
 154         return dt;
 155 }
 156
 157 /**
 158  * of_get_display_timings - parse all display_timing entries from a device_node
 159  * @np: device_node with the subnodes
 160  **/
 161 struct display_timings *of_get_display_timings(struct device_node *np)
 162 {
 163         struct device_node *timings_np;
 164         struct device_node *entry;
 165         struct device_node *native_mode;
 166         struct display_timings *disp;
 167
 168         if (!np) {
 169                 pr_err("%s: no devicenode given\n", of_node_full_name(np));
 170                 return NULL;
 171         }
 172
 173         timings_np = of_find_node_by_name(np, "display-timings");
 174         if (!timings_np) {
 175                 pr_err("%s: could not find display-timings node\n",
 176                         of_node_full_name(np));
 177                 return NULL;
 178         }
 179
 180         disp = kzalloc(sizeof(*disp), GFP_KERNEL);
 181         if (!disp) {
 182                 pr_err("%s: could not allocate struct disp'\n",
 183                         of_node_full_name(np));
 184                 goto dispfail;
 185         }
 186
 187         entry = of_parse_phandle(timings_np, "native-mode", 0);
 188         /* assume first child as native mode if none provided */
 189         if (!entry)
 190                 entry = of_get_next_child(np, NULL);
 191         /* if there is no child, it is useless to go on */
 192         if (!entry) {
 193                 pr_err("%s: no timing specifications given\n",
 194                         of_node_full_name(np));
 195                 goto entryfail;
 196         }
 197
 198         pr_debug("%s: using %s as default timing\n",
 199                 of_node_full_name(np), entry->name);
 200
 201         native_mode = entry;
 202
 203         disp->num_timings = of_get_child_count(timings_np);
 204         if (disp->num_timings == 0) {
 205                 /* should never happen, as entry was already found above */
 206                 pr_err("%s: no timings specified\n", of_node_full_name(np));
 207                 goto entryfail;
 208         }
 209
 210         disp->timings = kzalloc(sizeof(struct display_timing *) *
 211                                 disp->num_timings, GFP_KERNEL);
 212         if (!disp->timings) {
 213                 pr_err("%s: could not allocate timings array\n",
 214                         of_node_full_name(np));
 215                 goto entryfail;
 216         }
 217
 218         disp->num_timings = 0;
 219         disp->native_mode = 0;
 220
 221         for_each_child_of_node(timings_np, entry) {
 222                 struct display_timing *dt;
 223
 224                 dt = of_get_display_timing(entry);
 225                 if (!dt) {
 226                         /*
 227                          * to not encourage wrong devicetrees, fail in case of
 228                          * an error
 229                          */
 230                         pr_err("%s: error in timing %d\n",
 231                                 of_node_full_name(np), disp->num_timings + 1);
 232                         goto timingfail;
 233                 }
 234
 235                 if (native_mode == entry)
 236                         disp->native_mode = disp->num_timings;
 237
 238                 disp->timings[disp->num_timings] = dt;
 239                 disp->num_timings++;
 240         }
 241         of_node_put(timings_np);
 242         /*
 243          * native_mode points to the device_node returned by of_parse_phandle
 244          * therefore call of_node_put on it
 245          */
 246         of_node_put(native_mode);
 247
 248         pr_debug("%s: got %d timings. Using timing #%d as default\n",
 249                 of_node_full_name(np), disp->num_timings,
 250                 disp->native_mode + 1);
 251
 252         return disp;
 253
 254 timingfail:
 255         if (native_mode)
 256                 of_node_put(native_mode);
 257         display_timings_release(disp);
 258 entryfail:
 259         kfree(disp);
 260 dispfail:
 261         of_node_put(timings_np);
 262         return NULL;
 263 }
 264 EXPORT_SYMBOL_GPL(of_get_display_timings);
 265
 266 /**
 267  * of_display_timings_exist - check if a display-timings node is provided
 268  * @np: device_node with the timing
 269  **/
 270 int of_display_timings_exist(struct device_node *np)
 271 {
 272         struct device_node *timings_np;
 273
 274         if (!np)
 275                 return -EINVAL;
 276
 277         timings_np = of_parse_phandle(np, "display-timings", 0);
 278         if (!timings_np)
 279                 return -EINVAL;
 280
 281         of_node_put(timings_np);
 282         return 1;
 283 }
 284 EXPORT_SYMBOL_GPL(of_display_timings_exist);