[PATCH v3 2/5] media: meson: vdec: add helpers for lossless framebuffer compression buffers

[Neil Armstrong <narmstrong@baylibre.com>]

From: Maxime Jourdan <mjourdan@baylibre.com>

Add helpers to support the lossless framebuffer compression format that
will be used in HEVC & VP9 decoders when decoding 10bit content for
downsampling to 8bit NV12 and later proper compressed buffer support.

Signed-off-by: Maxime Jourdan <mjourdan@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 .../staging/media/meson/vdec/vdec_helpers.c   | 27 +++++++++++++++++++
 .../staging/media/meson/vdec/vdec_helpers.h   |  4 +++
 2 files changed, 31 insertions(+)

diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c
index fc59d8801643..818064b6b4d0 100644
--- a/drivers/staging/media/meson/vdec/vdec_helpers.c
+++ b/drivers/staging/media/meson/vdec/vdec_helpers.c
@@ -50,6 +50,33 @@ void amvdec_write_parser(struct amvdec_core *core, u32 reg, u32 val)
 }
 EXPORT_SYMBOL_GPL(amvdec_write_parser);
 
+/* 4 KiB per 64x32 block */
+u32 amvdec_am21c_body_size(u32 width, u32 height)
+{
+	u32 width_64 = ALIGN(width, 64) / 64;
+	u32 height_32 = ALIGN(height, 32) / 32;
+
+	return SZ_4K * width_64 * height_32;
+}
+EXPORT_SYMBOL_GPL(amvdec_am21c_body_size);
+
+/* 32 bytes per 128x64 block */
+u32 amvdec_am21c_head_size(u32 width, u32 height)
+{
+	u32 width_128 = ALIGN(width, 128) / 128;
+	u32 height_64 = ALIGN(height, 64) / 64;
+
+	return 32 * width_128 * height_64;
+}
+EXPORT_SYMBOL_GPL(amvdec_am21c_head_size);
+
+u32 amvdec_am21c_size(u32 width, u32 height)
+{
+	return ALIGN(amvdec_am21c_body_size(width, height) +
+		     amvdec_am21c_head_size(width, height), SZ_64K);
+}
+EXPORT_SYMBOL_GPL(amvdec_am21c_size);
+
 static int canvas_alloc(struct amvdec_session *sess, u8 *canvas_id)
 {
 	int ret;
diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.h b/drivers/staging/media/meson/vdec/vdec_helpers.h
index 165e6293ffba..cfaed52ab526 100644
--- a/drivers/staging/media/meson/vdec/vdec_helpers.h
+++ b/drivers/staging/media/meson/vdec/vdec_helpers.h
@@ -27,6 +27,10 @@ void amvdec_clear_dos_bits(struct amvdec_core *core, u32 reg, u32 val);
 u32 amvdec_read_parser(struct amvdec_core *core, u32 reg);
 void amvdec_write_parser(struct amvdec_core *core, u32 reg, u32 val);
 
+u32 amvdec_am21c_body_size(u32 width, u32 height);
+u32 amvdec_am21c_head_size(u32 width, u32 height);
+u32 amvdec_am21c_size(u32 width, u32 height);
+
 /**
  * amvdec_dst_buf_done_idx() - Signal that a buffer is done decoding
  *
-- 
2.22.0