[PATCH 22/23] [DO NOT MERGE] drm/format-helper: Support blitting from C1 to XRGB8888

[Thomas Zimmermann]

Implemented for drawing fonts, the C1-to-XRGB8888 blitting code writes
single bits into an XRGB8888-based buffer. The color is read from the
given palette.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 drivers/gpu/drm/drm_format_helper.c | 39 +++++++++++++++++++++++++++++
 include/drm/drm_format_helper.h     |  2 ++
 2 files changed, 41 insertions(+)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index 2588871672b6d..a61f45636a111 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -462,6 +462,45 @@ static void drm_fb_xrgb8888_to_rgb332_line(void *dbuf, const void *sbuf, unsigne
 	}
 }
 
+static void drm_fb_c1_to_xrgb8888_line(void *dbuf, const void *sbuf, unsigned int pixels,
+			       		 const struct drm_color_lut *palette)
+{
+	__le32 *dbuf32 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	unsigned int shift = 0;
+	unsigned int x;
+	u32 pix;
+	u32 bit;
+	u32 val32;
+
+	for (x = 0; x < pixels; x++) {
+		if (!shift) {
+			pix = le32_to_cpu(sbuf32[x / 32]);
+			shift = 32;
+		}
+		--shift;
+		bit = (pix >> shift) & BIT(0);
+
+		val32 = GENMASK(31, 24) |
+			((palette[bit].red   >> 8) << 16) |
+			((palette[bit].green >> 8) << 8) |
+			((palette[bit].blue  >> 8));
+		dbuf32[x] = cpu_to_le32(val32);
+	}
+}
+
+void drm_fb_c1_to_xrgb8888(struct iosys_map *dst, const unsigned int *dst_pitch,
+			   const struct drm_pixmap *src_pix, struct drm_format_conv_state *state)
+{
+	static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+		4,
+	};
+
+	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src_pix, false, state,
+		    drm_fb_c1_to_xrgb8888_line);
+}
+EXPORT_SYMBOL(drm_fb_c1_to_xrgb8888);
+
 /**
  * drm_fb_xrgb8888_to_rgb332 - Convert XRGB8888 to RGB332 clip buffer
  * @dst: Array of RGB332 destination buffers
diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h
index 464812080f3dc..d5ee8bdb0f619 100644
--- a/include/drm/drm_format_helper.h
+++ b/include/drm/drm_format_helper.h
@@ -109,6 +109,8 @@ void drm_fb_swab(struct drm_device *dev,
 		 struct iosys_map *dst, const unsigned int *dst_pitch,
 		 const struct drm_pixmap *src_pix, bool cached,
 		 struct drm_format_conv_state *state);
+void drm_fb_c1_to_xrgb8888(struct iosys_map *dst, const unsigned int *dst_pitch,
+			   const struct drm_pixmap *src_pix, struct drm_format_conv_state *state);
 void drm_fb_xrgb8888_to_rgb332(struct iosys_map *dst, const unsigned int *dst_pitch,
 			       const struct drm_pixmap *src_pix, struct drm_format_conv_state *state);
 void drm_fb_xrgb8888_to_rgb565(struct iosys_map *dst, const unsigned int *dst_pitch,
-- 
2.43.0