Add screen_info_pixel_format(), which converts a screen_info's
information about the color format to struct pixel_format. The encoding
within the screen_info structure is complex and therefore prone to
errors. Later patches will convert callers to use the pixel format.
Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de>
Reviewed-by: Javier Martinez Canillas <javi...@redhat.com>
---
drivers/video/screen_info_generic.c | 55 +++++++++++++++++++++++++++++
include/linux/screen_info.h | 2 ++
2 files changed, 57 insertions(+)
diff --git a/drivers/video/screen_info_generic.c
b/drivers/video/screen_info_generic.c
index 900e9386eceb..763adbba71cb 100644
--- a/drivers/video/screen_info_generic.c
+++ b/drivers/video/screen_info_generic.c
@@ -5,6 +5,8 @@
#include <linux/screen_info.h>
#include <linux/string.h>
+#include <video/pixel_format.h>
+
static void resource_init_named(struct resource *r,
resource_size_t start, resource_size_t size,
const char *name, unsigned int flags)
@@ -180,3 +182,56 @@ u32 __screen_info_lfb_bits_per_pixel(const struct
screen_info *si)
return bits_per_pixel;
}
EXPORT_SYMBOL(__screen_info_lfb_bits_per_pixel);
+
+static int __screen_info_lfb_pixel_format(const struct screen_info *si, struct
pixel_format *f)
+{
+ u32 bits_per_pixel = __screen_info_lfb_bits_per_pixel(si);
+
+ if (bits_per_pixel > U8_MAX)
+ return -EINVAL;
+
+ f->bits_per_pixel = bits_per_pixel;
+
+ if (si->lfb_depth > 8) {
+ f->indexed = false;
+ f->alpha.offset = 0;
+ f->alpha.length = 0;
+ f->red.offset = si->red_pos;
+ f->red.length = si->red_size;
+ f->green.offset = si->green_pos;
+ f->green.length = si->green_size;
+ f->blue.offset = si->blue_pos;
+ f->blue.length = si->blue_size;
+ } else {
+ f->indexed = true;
+ f->index.offset = 0;
+ f->index.length = si->lfb_depth;
+ }
+
+ return 0;
+}
+
+/**
+ * screen_info_pixel_format - Returns the screen-info format as pixel-format
description
+ *
+ * @si: the screen_info
+ * @f: pointer to return pixel-format description
+ *
+ * Returns:
+ * 0 on success, or a negative errno code otherwise.
+ */
+int screen_info_pixel_format(const struct screen_info *si, struct pixel_format
*f)
+{
+ unsigned int type = screen_info_video_type(si);
+
+ /* TODO: Add support for additional types as needed. */
+ switch (type) {
+ case VIDEO_TYPE_VLFB:
+ case VIDEO_TYPE_EFI:
+ return __screen_info_lfb_pixel_format(si, f);
+ }
+
+ /* not supported */
+ return -EINVAL;
+}
+EXPORT_SYMBOL(screen_info_pixel_format);
diff --git a/include/linux/screen_info.h b/include/linux/screen_info.h
index 923d68e07679..1690706206e8 100644
--- a/include/linux/screen_info.h
+++ b/include/linux/screen_info.h
@@ -12,6 +12,7 @@
#define SCREEN_INFO_MAX_RESOURCES 3
struct pci_dev;
+struct pixel_format;
struct resource;
static inline bool __screen_info_has_lfb(unsigned int type)
@@ -136,6 +137,7 @@ static inline u32 __screen_info_vesapm_info_base(const
struct screen_info *si)
ssize_t screen_info_resources(const struct screen_info *si, struct resource
*r, size_t num);
u32 __screen_info_lfb_bits_per_pixel(const struct screen_info *si);
+int screen_info_pixel_format(const struct screen_info *si, struct pixel_format
*f);
#if defined(CONFIG_PCI)
void screen_info_apply_fixups(void);
--
2.50.0
