include: drm_fourcc: Add Bayer FourCC and modifiers

Add Bayer format and modifiers for patch submitted for upstream
inclusion. The formats have not been accepted upstream yet but is needed
to progress with RAW capture support in libcamera.

Intention is to merge this in libcamera and update the header file the
upstream patch is picked up upstream.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 94 insertions, 0 deletions

diff --git a/include/linux/drm_fourcc.h b/include/linux/drm_fourcc.h
index 4bb1bfe9..69240dfe 100644
--- a/include/linux/drm_fourcc.h
+++ b/include/linux/drm_fourcc.h
@@ -289,6 +289,62 @@ extern "C" {
 #define DRM_FORMAT_MJPEG	fourcc_code('M', 'J', 'P', 'G') /* Motion-JPEG */
 
 /*
+ * Bayer formats
+ *
+ * Bayer formats contain green, red and blue components, with alternating lines
+ * of red and green, and blue and green pixels in different orders. For each
+ * block of 2x2 pixels there is one pixel with a red filter, two with a green
+ * filter, and one with a blue filter. The filters can be arranged in different
+ * patterns.
+ *
+ * For example, RGGB:
+ *	row0: RGRGRGRG...
+ *	row1: GBGBGBGB...
+ *	row3: RGRGRGRG...
+ *	row4: GBGBGBGB...
+ *	...
+ *
+ * Vendors have different methods to pack the sampling formats to increase data
+ * density. For this reason the fourcc only describes pixel sample size and the
+ * filter pattern for each block of 2x2 pixels. A modifier is needed to
+ * describe the memory layout.
+ *
+ * In addition to vendor modifiers for memory layout DRM_FORMAT_MOD_LINEAR may
+ * be used to describe a layout where all samples are placed consecutively in
+ * memory. If the sample does not fit inside a single byte, the sample storage
+ * is extended to the minimum number of (little endian) bytes that can hold the
+ * sample and any unused most-significant bits are defined as padding.
+ *
+ * For example, SRGGB10:
+ * Each 10-bit sample is contained in 2 consecutive little endian bytes, where
+ * the 6 most-significant bits are unused.
+ */
+
+/* 8-bit Bayer formats */
+#define DRM_FORMAT_SRGGB8	fourcc_code('R', 'G', 'G', 'B')
+#define DRM_FORMAT_SGRBG8	fourcc_code('G', 'R', 'B', 'G')
+#define DRM_FORMAT_SGBRG8	fourcc_code('G', 'B', 'R', 'G')
+#define DRM_FORMAT_SBGGR8	fourcc_code('B', 'A', '8', '1')
+
+/* 10-bit Bayer formats */
+#define DRM_FORMAT_SRGGB10	fourcc_code('R', 'G', '1', '0')
+#define DRM_FORMAT_SGRBG10	fourcc_code('B', 'A', '1', '0')
+#define DRM_FORMAT_SGBRG10	fourcc_code('G', 'B', '1', '0')
+#define DRM_FORMAT_SBGGR10	fourcc_code('B', 'G', '1', '0')
+
+/* 12-bit Bayer formats */
+#define DRM_FORMAT_SRGGB12	fourcc_code('R', 'G', '1', '2')
+#define DRM_FORMAT_SGRBG12	fourcc_code('B', 'A', '1', '2')
+#define DRM_FORMAT_SGBRG12	fourcc_code('G', 'B', '1', '2')
+#define DRM_FORMAT_SBGGR12	fourcc_code('B', 'G', '1', '2')
+
+/* 14-bit Bayer formats */
+#define DRM_FORMAT_SRGGB14	fourcc_code('R', 'G', '1', '4')
+#define DRM_FORMAT_SGRBG14	fourcc_code('B', 'A', '1', '4')
+#define DRM_FORMAT_SGBRG14	fourcc_code('G', 'B', '1', '4')
+#define DRM_FORMAT_SBGGR14	fourcc_code('B', 'G', '1', '4')
+
+/*
  * Format Modifiers:
  *
  * Format modifiers describe, typically, a re-ordering or modification
@@ -311,6 +367,7 @@ extern "C" {
 #define DRM_FORMAT_MOD_VENDOR_BROADCOM 0x07
 #define DRM_FORMAT_MOD_VENDOR_ARM     0x08
 #define DRM_FORMAT_MOD_VENDOR_ALLWINNER 0x09
+#define DRM_FORMAT_MOD_VENDOR_MIPI 0x0a
 
 /* add more to the end as needed */
 
@@ -413,6 +470,16 @@ extern "C" {
 #define I915_FORMAT_MOD_Yf_TILED_CCS	fourcc_mod_code(INTEL, 5)
 
 /*
+ * IPU3 Bayer packing layout
+ *
+ * The IPU3 raw Bayer formats use a custom packing layout where there are no
+ * gaps between each 10-bit sample. It packs 25 pixels into 32 bytes leaving
+ * the 6 most significant bits in the last byte unused. The format is little
+ * endian.
+ */
+#define IPU3_FORMAT_MOD_PACKED fourcc_mod_code(INTEL, 8)
+
+/*
  * Tiled, NV12MT, grouped in 64 (pixels) x 32 (lines) -sized macroblocks
  *
  * Macroblocks are laid in a Z-shape, and each pixel data is following the
@@ -758,6 +825,33 @@ extern "C" {
  */
 #define DRM_FORMAT_MOD_ALLWINNER_TILED fourcc_mod_code(ALLWINNER, 1)
 
+/* Mobile Industry Processor Interface (MIPI) modifiers */
+
+/*
+ * MIPI CSI-2 packing layout
+ *
+ * The CSI-2 RAW formats (for example Bayer) use a different packing layout
+ * depenindg on the sample size.
+ *
+ * - 10-bits per sample
+ *   Every four consecutive samples are packed into 5 bytes. Each of the first 4
+ *   bytes contain the 8 high order bits of the pixels, and the 5th byte
+ *   contains the 2 least-significant bits of each pixel, in the same order.
+ *
+ * - 12-bits per sample
+ *   Every two consecutive samples are packed into three bytes. Each of the
+ *   first two bytes contain the 8 high order bits of the pixels, and the third
+ *   byte contains the four least-significant bits of each pixel, in the same
+ *   order.
+ *
+ * - 14-bits per sample
+ *   Every four consecutive samples are packed into seven bytes. Each of the
+ *   first four bytes contain the eight high order bits of the pixels, and the
+ *   three following bytes contains the six least-significant bits of each
+ *   pixel, in the same order.
+ */
+#define MIPI_FORMAT_MOD_CSI2_PACKED fourcc_mod_code(MIPI, 1)
+
 #if defined(__cplusplus)
 }
 #endif