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path: root/drivers/video/fbdev/core/fb_info.c
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Diffstat (limited to 'drivers/video/fbdev/core/fb_info.c')
-rw-r--r--drivers/video/fbdev/core/fb_info.c79
1 files changed, 79 insertions, 0 deletions
diff --git a/drivers/video/fbdev/core/fb_info.c b/drivers/video/fbdev/core/fb_info.c
new file mode 100644
index 000000000000..4847ebe50d7d
--- /dev/null
+++ b/drivers/video/fbdev/core/fb_info.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/export.h>
+#include <linux/fb.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+
+/**
+ * framebuffer_alloc - creates a new frame buffer info structure
+ *
+ * @size: size of driver private data, can be zero
+ * @dev: pointer to the device for this fb, this can be NULL
+ *
+ * Creates a new frame buffer info structure. Also reserves @size bytes
+ * for driver private data (info->par). info->par (if any) will be
+ * aligned to sizeof(long). The new instances of struct fb_info and
+ * the driver private data are both cleared to zero.
+ *
+ * Returns the new structure, or NULL if an error occurred.
+ *
+ */
+struct fb_info *framebuffer_alloc(size_t size, struct device *dev)
+{
+#define BYTES_PER_LONG (BITS_PER_LONG/8)
+#define PADDING (BYTES_PER_LONG - (sizeof(struct fb_info) % BYTES_PER_LONG))
+ int fb_info_size = sizeof(struct fb_info);
+ struct fb_info *info;
+ char *p;
+
+ if (size)
+ fb_info_size += PADDING;
+
+ p = kzalloc(fb_info_size + size, GFP_KERNEL);
+
+ if (!p)
+ return NULL;
+
+ info = (struct fb_info *) p;
+
+ if (size)
+ info->par = p + fb_info_size;
+
+ info->device = dev;
+ info->fbcon_rotate_hint = -1;
+
+#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
+ mutex_init(&info->bl_curve_mutex);
+#endif
+
+ return info;
+#undef PADDING
+#undef BYTES_PER_LONG
+}
+EXPORT_SYMBOL(framebuffer_alloc);
+
+/**
+ * framebuffer_release - marks the structure available for freeing
+ *
+ * @info: frame buffer info structure
+ *
+ * Drop the reference count of the device embedded in the
+ * framebuffer info structure.
+ *
+ */
+void framebuffer_release(struct fb_info *info)
+{
+ if (!info)
+ return;
+
+ if (WARN_ON(refcount_read(&info->count)))
+ return;
+
+#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
+ mutex_destroy(&info->bl_curve_mutex);
+#endif
+
+ kfree(info);
+}
+EXPORT_SYMBOL(framebuffer_release);