m + beginning of gamma

Signed-off-by: Mattias Andrée <maandree@operamail.com>

4 files changed, 191 insertions, 8 deletions

diff --git a/src/drmgamma.c b/src/drmgamma.c
new file mode 100644
index 0000000..0a8f72f
--- /dev/null
+++ b/src/drmgamma.c
@@ -0,0 +1,108 @@
+/**
+ * crt-calibrator – Calibration utility for CRT monitors
+ * 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 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 "drmgamma.h"
+
+#include <unistd.h>
+#include <errno.h>
+#include <stdio.h>
+#include <fcntl.h>
+
+
+
+/**
+ * Close on exec flag for `open`
+ */
+#ifndef O_CLOEXEC
+# define O_CLOEXEC  02000000
+#endif
+
+
+/**
+ * The number of elements to allocates to a buffer for a DRM device pathname
+ */
+#define DRM_DEV_NAME_MAX_LEN  \
+  ((sizeof(DRM_DEV_NAME) + sizeof(DRM_DIR_NAME)) / sizeof(char) + 3 * sizeof(int))
+
+
+
+/**
+ * Figure out how many graphics cards there are on the system
+ * 
+ * @return  The number of graphics cards on the system
+ */
+size_t drm_card_count(void)
+{
+  char buf[DRM_DEV_NAME_MAX_LEN];
+  size_t count = 0;
+  
+  for (;; count++)
+    {
+      sprintf(buf, DRM_DEV_NAME, DRM_DIR_NAME, (int)count);
+      if (access(buf, F_OK) < 0)
+	return count;
+    }
+
+}
+
+/**
+ * Acquire access to a graphics card
+ * 
+ * @param   index  The index of the graphics card
+ * @param   card   Graphics card information to fill in
+ * @return         Zero on success, -1 on error
+ */
+int drm_card_open(size_t index, drm_card_t* restrict card)
+{
+  char buf[DRM_DEV_NAME_MAX_LEN];
+  int old_errno;
+  
+  card->fd = -1;
+  card->res = NULL;
+  
+  sprintf(buf, DRM_DEV_NAME, DRM_DIR_NAME, (int)index);
+  card->fd = open(buf, O_RDWR | O_CLOEXEC);
+  if (card->fd == -1)
+    goto fail;
+  
+  card->res = drmModeGetResources(card->fd);
+  if (card->res == NULL)
+    goto fail;
+  
+  card->crtc_count = (size_t)(card->res->count_crtcs);
+  
+  return 0;
+ fail:
+  old_errno = errno;
+  drm_card_close(card);
+  errno = old_errno;
+  return -1;
+}
+
+
+/**
+ * Release access to a graphics card
+ * 
+ * @param  card  The graphics card information
+ */
+void drm_card_close(drm_card_t* restrict card)
+{
+  if (card->res != NULL)
+    drmModeFreeResources(card->res), card->res = NULL;
+  if (card->fd != -1)
+    close(card->fd), card->fd = -1;
+}
diff --git a/src/drmgamma.h b/src/drmgamma.h
new file mode 100644
index 0000000..7044fd7
--- /dev/null
+++ b/src/drmgamma.h
@@ -0,0 +1,75 @@
+/**
+ * crt-calibrator – Calibration utility for CRT monitors
+ * 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 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/>.
+ */
+#ifndef CRT_CALIBRATOR_DRMGAMMA_H
+#define CRT_CALIBRATOR_DRMGAMMA_H
+
+
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+
+/**
+ * Graphics card information
+ */
+typedef struct drm_card
+{
+  /**
+   * File descriptor for the connection to the graphics card,
+   * -1 if not opened
+   */
+  int fd;
+  
+  /**
+   * The graphics card's mode resources, `NULL` if not acquired
+   */
+  drmModeRes* restrict res;
+  
+  /**
+   * The number of CRTC:s available on the graphics card
+   */
+  size_t crtc_count;
+  
+} drm_card_t;
+
+
+/**
+ * Figure out how many graphics cards there are on the system
+ * 
+ * @return  The number of graphics cards on the system
+ */
+size_t drm_card_count(void);
+
+/**
+ * Acquire access to a graphics card
+ * 
+ * @param   index  The index of the graphics card
+ * @param   card   Graphics card information to fill in
+ * @return         Zero on success, -1 on error
+ */
+int drm_card_open(size_t index, drm_card_t* restrict card);
+
+/**
+ * Release access to a graphics card
+ * 
+ * @param  card  The graphics card information
+ */
+void drm_card_close(drm_card_t* restrict card);
+
+
+#endif
+
diff --git a/src/framebuffer.c b/src/framebuffer.c
index b830d6e..f783671 100644
--- a/src/framebuffer.c
+++ b/src/framebuffer.c
@@ -76,12 +76,12 @@ int fb_open(size_t index, framebuffer_t* restrict fb)
   struct fb_var_screeninfo var_info;
   int old_errno;
   
-  fb->fd = 0;
+  fb->fd = -1;
   fb->mem = MAP_FAILED;
   
   sprintf(buf, FB_DEVICE_PATTERN, index);
   fb->fd = open(buf, O_RDWR);
-  if (fb->fd == 0)
+  if (fb->fd == -1)
     goto fail;
   
   if (ioctl(fb->fd, FBIOGET_FSCREENINFO, &fix_info) ||
@@ -116,8 +116,8 @@ int fb_open(size_t index, framebuffer_t* restrict fb)
  */
 void fb_close(framebuffer_t* restrict fb)
 {
-  if (fb->fd)
-    close(fb->fd);
+  if (fb->fd != -1)
+    close(fb->fd), fb->fd = -1;
 }
 
 
diff --git a/src/framebuffer.h b/src/framebuffer.h
index 7ef1fed..f6b99ea 100644
--- a/src/framebuffer.h
+++ b/src/framebuffer.h
@@ -15,8 +15,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef CRT_CALIBRATOR_H
-#define CRT_CALIBRATOR_H
+#ifndef CRT_CALIBRATOR_FRAMEBUFFER_H
+#define CRT_CALIBRATOR_FRAMEBUFFER_H
 
 
 #include <stddef.h>
@@ -29,7 +29,7 @@
 typedef struct framebuffer
 {
   /**
-   * The file descriptor used to access the framebuffer, 0 if not opened
+   * The file descriptor used to access the framebuffer, -1 if not opened
    */
   int fd;
   
@@ -72,7 +72,7 @@ size_t fb_count(void);
  * Open a framebuffer
  * 
  * @param   index  The index of the framebuffer to open
- * @param   fb     Framevuffer information to fill in
+ * @param   fb     Framebuffer information to fill in
  * @return         Zero on success, -1 on error
  */
 int fb_open(size_t index, framebuffer_t* restrict fb);