Merge branch 'drm'

1 files changed, 446 insertions, 0 deletions

diff --git a/src/blueshift_drm_c.c b/src/blueshift_drm_c.c
new file mode 100644
index 0000000..4e8c750
--- /dev/null
+++ b/src/blueshift_drm_c.c
@@ -0,0 +1,446 @@
+/**
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <alloca.h>
+
+#ifndef O_CLOEXEC
+  #define O_CLOEXEC  02000000
+#endif
+
+/* Requires video group */
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+
+
+/**
+ * File descriptor for the DRM connection
+ */
+static int drm_fd;
+
+/**
+ * DRM mode resources
+ */
+static drmModeRes* drm_res = NULL;
+
+/**
+ * Connector information
+ */
+static drmModeConnector* connector = NULL;
+
+
+
+/**
+ * Get the number of cards present on the system
+ * 
+ * @return  The number of cards present on the system
+ */
+int blueshift_drm_card_count()
+{
+  long maxlen = strlen(DRM_DIR_NAME) + strlen(DRM_DEV_NAME) + 10;
+  char* pathname = alloca(maxlen * sizeof(char));
+  int count = 0;
+  struct stat attr;
+  
+  for (;;)
+    {
+      sprintf(pathname, DRM_DEV_NAME, DRM_DIR_NAME, count);
+      if (stat(pathname, &attr))
+	break;
+      count++;
+    }
+  
+  return count;
+}
+
+
+/**
+ * Open connection to a graphics card
+ * 
+ * @param   card  The index of the graphics card
+ * @return        Zero on success
+ */
+int blueshift_drm_open(int card)
+{
+  long maxlen = strlen(DRM_DIR_NAME) + strlen(DRM_DEV_NAME) + 10;
+  char* pathname = alloca(maxlen * sizeof(char));
+  
+  sprintf(pathname, DRM_DEV_NAME, DRM_DIR_NAME, card);
+  
+  drm_fd = open(pathname, O_RDWR | O_CLOEXEC);
+  if (drm_fd < 0)
+    {
+      perror("open");
+      return 1;
+    }
+  
+  return 0;
+}
+
+
+/**
+ * Close connection to the graphics card
+ */
+void blueshift_drm_close()
+{
+  drmModeFreeResources(drm_res);
+  close(drm_fd);
+}
+
+
+/**
+ * Update the resource, required after `blueshift_drm_open`
+ */
+void blueshift_drm_update()
+{
+  if (drm_res)
+    drmModeFreeResources(drm_res);
+  
+  drm_res = drmModeGetResources(drm_fd);
+}
+
+
+/**
+ * Return the number of CRTC:s on the opened card
+ * 
+ * @return  The number of CRTC:s on the opened card
+ */
+int blueshift_drm_crtc_count()
+{
+  return drm_res->count_crtcs;
+}
+
+
+/**
+ * Return the number of connectors on the opened card
+ * 
+ * @return  The number of connectors on the opened card
+ */
+int blueshift_drm_connector_count()
+{
+  return drm_res->count_connectors;
+}
+
+
+/**
+ * Return the size of the gamma ramps on a CRTC
+ * 
+ * @param   crtc_index  The index of the CRTC
+ * @return              The size of the gamma ramps on a CRTC
+ */
+int blueshift_drm_gamma_size(int crtc_index)
+{
+  drmModeCrtc* crtc = drmModeGetCrtc(drm_fd, *(drm_res->crtcs + crtc_index));
+  int gamma_size;
+  
+  gamma_size = crtc->gamma_size;
+  drmModeFreeCrtc(crtc);
+  
+  return gamma_size;
+}
+
+
+/**
+ * Acquire information about a connector
+ * 
+ * @param  connector_index  The index of the connector
+ */
+void blueshift_drm_open_connector(int connector_index)
+{
+  connector = drmModeGetConnector(drm_fd, *(drm_res->connectors + connector_index));
+}
+
+
+/**
+ * Release information about the connector
+ */
+void blueshift_drm_close_connector()
+{
+  drmModeFreeConnector(connector);
+}
+
+
+/* Accurate dimension on area not covered by the edges */
+
+/**
+ * Get the physical width the monitor connected to the connector
+ * 
+ * @return  The physical width of the monitor in millimetres, 0 if unknown or not connected
+ */
+int blueshift_drm_get_width()
+{
+  return connector->mmWidth;
+}
+
+
+/**
+ * Get the physical height the monitor connected to the connector
+ * 
+ * @return  The physical height of the monitor in millimetres, 0 if unknown or not connected
+ */
+int blueshift_drm_get_height()
+{
+  return connector->mmHeight;
+}
+
+
+/**
+ * Get whether a monitor is connected to a connector
+ * 
+ * @return  1 if there is a connection, 0 otherwise, -1 if unknown
+ */
+int blueshift_drm_is_connected()
+{
+  switch (connector->connection)
+    {
+    case DRM_MODE_CONNECTED:
+      return 1;
+    case DRM_MODE_DISCONNECTED:
+      return 0;
+    case DRM_MODE_UNKNOWNCONNECTION:
+    default:
+      return -1;
+    }
+}
+
+
+/**
+ * Get the index of the CRTC of the monitor connected to the connector
+ * 
+ * @return  The index of the CRTC
+ */
+int blueshift_drm_get_crtc()
+{
+  drmModeEncoder* encoder = drmModeGetEncoder(drm_fd, connector->encoder_id);
+  uint32_t crtc_id = encoder->crtc_id;
+  int crtc;
+  
+  drmModeFreeEncoder(encoder);
+  
+  for (crtc = 0; crtc < drm_res->count_crtcs; crtc++)
+    if (*(drm_res->crtcs + crtc) == crtc_id)
+      return crtc;
+  
+  return -1;
+}
+
+
+/**
+ * Get the index of the type of the connector
+ * 
+ * @return  The connector type by index, 0 for unknown
+ */
+int blueshift_drm_get_connector_type_index()
+{
+  return connector->connector_type;
+}
+
+
+/**
+ * Get the name of the type of the connector
+ * 
+ * @return  The connector type by name, "Unknown" if not identifiable,
+ *          "Unrecognised" if Blueshift does not recognise it.
+ */
+const char* blueshift_drm_get_connector_type_name()
+{
+  static const char* TYPE_NAMES[] = {
+    "Unknown", "VGA", "DVII", "DVID", "DVIA", "Composite", "SVIDEO", "LVDS", "Component",
+    "9PinDIN", "DisplayPort", "HDMIA", "HDMIB", "TV", "eDP", "VIRTUAL", "DSI"};
+  
+  int type = connector->connector_type;
+  return (size_t)type < sizeof(TYPE_NAMES) / sizeof(char*) ? TYPE_NAMES[type] : "Unrecognised";
+}
+
+
+/**
+ * Get the current gamma ramps of the 
+ * 
+ * @param   crtc_index  The index of the CRTC to read from
+ * @param   gamma_size  The size a gamma ramp
+ * @param   red         Storage location for the red gamma ramp
+ * @param   green       Storage location for the green gamma ramp
+ * @param   blue        Storage location for the blue gamma ramp
+ * @return              Zero on success
+ */
+int blueshift_drm_get_gamma_ramps(int crtc_index, int gamma_size, uint16_t* red, uint16_t* green, uint16_t* blue)
+{
+  int i;
+  
+  /* We need to initialise it to avoid valgrind warnings */
+  for (i = 0; i < gamma_size; i++)
+    *(red + i) = *(green + i) = *(blue + i) = 0;
+  
+  return drmModeCrtcGetGamma(drm_fd, *(drm_res->crtcs + crtc_index), gamma_size, red, green, blue);
+}
+
+
+/**
+ * Get the extended display identification data for the monitor connected to the connector
+ * 
+ * @param   edid  Storage location for the EDID, it should be 128 bytes, 256 bytes + zero termination if hex
+ * @param   size  The size allocated to `edid` excluding your zero termination
+ * @param   hex   Whether to convert to hexadecimal representation, this is preferable
+ * @return        The length of the found value, 0 if none, as if hex is false
+ */
+long blueshift_drm_get_edid(char* edid, long size, int hex)
+{
+  long rc = 0;
+  int prop_i;
+  for (prop_i = 0; prop_i < connector->count_props; prop_i++)
+    {
+      drmModePropertyRes* prop = drmModeGetProperty(drm_fd, connector->props[prop_i]);
+      if (!strcmp("EDID", prop->name))
+	{
+	  drmModePropertyBlobRes* blob = drmModeGetPropertyBlob(drm_fd, connector->prop_values[prop_i]);
+	  if (hex)
+	    {
+	      rc += blob->length;
+	      uint32_t n = size / 2;
+	      uint32_t i;
+	      if (n < blob->length)
+		n = blob->length;
+	      for (i = 0; i < n ; i++)
+		{
+		  *(edid + i * 2 + 0) = "0123456789abcdef"[(*((char*)(blob->data) + i) >> 4) & 15];
+		  *(edid + i * 2 + 1) = "0123456789abcdef"[(*((char*)(blob->data) + i) >> 0) & 15];
+		}
+	    }
+	  else
+	    memcpy(edid, blob->data, (blob->length < size ? blob->length : size) * sizeof(char));
+	  drmModeFreePropertyBlob(blob);
+	  prop_i = connector->count_props; /* stop to for loop */
+	}
+      drmModeFreeProperty(prop);
+    }
+  return rc;
+}
+
+
+
+int main(int argc, char** argv)
+{
+  int card_n = blueshift_drm_card_count();
+  int card_i;
+  
+  (void) argc;
+  (void) argv;
+  
+  printf("Card count: %i\n", card_n);
+  for (card_i = 0; card_i < card_n; card_i++)
+    {
+      int connector_n;
+      int connector_i;
+      
+      printf("Card: %i\n", card_i);
+      
+      blueshift_drm_open(0);
+      blueshift_drm_update();
+      
+      connector_n = blueshift_drm_connector_count();
+      
+      printf("  CRTC count: %i\n", blueshift_drm_crtc_count());
+      printf("  Connector count: %i\n", connector_n);
+      
+      for (connector_i = 0; connector_i < connector_n; connector_i++)
+	{
+	  int crtc;
+	  
+	  blueshift_drm_open_connector(connector_i);
+	  
+	  printf("  Connector: %i\n",
+		 connector_i);
+	  printf("    Connected: %i\n",
+		 blueshift_drm_is_connected());
+	  printf("    Connector type: %s (%i)\n",
+		 blueshift_drm_get_connector_type_name(),
+		 blueshift_drm_get_connector_type_index());
+	  
+	  if (blueshift_drm_is_connected() == 1)
+	    {
+	      long size = 128;
+	      char* edid = malloc((size * 2 + 1) * sizeof(char));
+	      long n;
+	      
+	      printf("    Physical size: %i mm by %i mm\n",
+		     blueshift_drm_get_width(),
+		     blueshift_drm_get_height());
+	      
+	      if ((n = blueshift_drm_get_edid(edid, size, 1)))
+		{
+		  if (n > size)
+		    {
+		      size = n;
+		      edid = realloc(edid, (size * 2 + 1) * sizeof(char));
+		      blueshift_drm_get_edid(edid, size, 1);
+		    }
+		  *(edid + n * 2) = 0;
+		  printf("    EDID: %s\n", edid);
+		}
+	      free(edid);
+	      
+	      if ((crtc = blueshift_drm_get_crtc()) >= 0)
+		{
+		  int gamma_size = blueshift_drm_gamma_size(crtc);
+		  uint16_t* red = alloca(3 * gamma_size * sizeof(uint16_t));
+		  uint16_t* green = red + gamma_size;
+		  uint16_t* blue = green + gamma_size;
+		  
+		  printf("    CRTC: %i\n", crtc);
+		  printf("    Gamma size: %i\n", gamma_size);
+		  
+		  if (!blueshift_drm_get_gamma_ramps(crtc, gamma_size, red, green, blue))
+		    {
+		      int j;
+		      printf("    Red:");
+		      for (j = 0; j < gamma_size; j++)
+			printf(" %u", *(red + j));
+		      printf("\n    Green:");
+		      for (j = 0; j < gamma_size; j++)
+			printf(" %u", *(green + j));
+		      printf("\n    Blue:");
+		      for (j = 0; j < gamma_size; j++)
+			printf(" %u", *(blue + j));
+		      printf("\n");
+		      
+		      for (j = 0; j < gamma_size; j++)
+			*(red + j) /= 2;
+		      for (j = 0; j < gamma_size; j++)
+			*(green + j) /= 2;
+		      for (j = 0; j < gamma_size; j++)
+			*(blue + j) /= 2;
+		      
+		      drmModeCrtcSetGamma(drm_fd, *(drm_res->crtcs + crtc), gamma_size, red, green, blue);
+		      /* Fails if inside a graphical environment */
+		    }
+		}
+	    }
+	  
+	  blueshift_drm_close_connector();
+	}
+    }
+  blueshift_drm_close();
+  
+  return 0;
+}
+