[v9,4/8] drm/msm: Add MSM-specific DSC helper methods

Commit Message

Jessica Zhang May 10, 2023, 10:54 p.m. UTC

Introduce MSM-specific DSC helper methods, as some calculations are
common between DP and DSC.

Signed-off-by: Jessica Zhang <[e-mail]>
---
 drivers/gpu/drm/msm/Makefile         |  1 +
 drivers/gpu/drm/msm/msm_dsc_helper.c | 26 ++++++++++++++
 drivers/gpu/drm/msm/msm_dsc_helper.h | 69 ++++++++++++++++++++++++++++++++++++
 3 files changed, 96 insertions(+)

Patch

diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile
index 7274c41228ed..b814fc80e2d5 100644
--- a/drivers/gpu/drm/msm/Makefile
+++ b/drivers/gpu/drm/msm/Makefile
@@ -94,6 +94,7 @@  msm-y += \
 	msm_atomic_tracepoints.o \
 	msm_debugfs.o \
 	msm_drv.o \
+	msm_dsc_helper.o \
 	msm_fb.o \
 	msm_fence.o \
 	msm_gem.o \
diff --git a/drivers/gpu/drm/msm/msm_dsc_helper.c b/drivers/gpu/drm/msm/msm_dsc_helper.c
new file mode 100644
index 000000000000..094decad9aea
--- /dev/null
+++ b/drivers/gpu/drm/msm/msm_dsc_helper.c
@@ -0,0 +1,26 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved
+ */
+
+#include <linux/kernel.h>
+#include <drm/drm_fixed.h>
+
+#include "msm_dsc_helper.h"
+
+s64 msm_dsc_get_bytes_per_slice(struct drm_dsc_config *dsc)
+{
+	return drm_fixp_from_fraction(dsc->slice_width * msm_dsc_get_bpp_int(dsc), 8);
+}
+
+u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int intf_width)
+{
+	u32 bytes_per_slice;
+	s64 bytes_per_slice_fp;
+	int slice_per_intf = msm_dsc_get_slice_per_intf(dsc, intf_width);
+
+	bytes_per_slice_fp = msm_dsc_get_bytes_per_slice(dsc);
+	bytes_per_slice = drm_fixp2int_ceil(bytes_per_slice_fp);
+
+	return bytes_per_slice * slice_per_intf;
+}
diff --git a/drivers/gpu/drm/msm/msm_dsc_helper.h b/drivers/gpu/drm/msm/msm_dsc_helper.h
new file mode 100644
index 000000000000..ba4c57df9f66
--- /dev/null
+++ b/drivers/gpu/drm/msm/msm_dsc_helper.h
@@ -0,0 +1,69 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved
+ */
+
+#ifndef MSM_DSC_HELPER_H_
+#define MSM_DSC_HELPER_H_
+
+#include <linux/bug.h>
+#include <linux/math.h>
+#include <drm/display/drm_dsc_helper.h>
+
+/*
+ * Helper methods for MSM specific DSC calculations that are common between timing engine,
+ * DSI, and DP.
+ */
+
+/**
+ * msm_dsc_get_bpp_int() - get bits per pixel integer value
+ * @dsc: Pointer to drm dsc config struct
+ * Returns: BPP integer value
+ */
+static inline int msm_dsc_get_bpp_int(struct drm_dsc_config *dsc)
+{
+	WARN_ON_ONCE(dsc->bits_per_pixel & 0xf);
+	return dsc->bits_per_pixel >> 4;
+}
+
+/**
+ * msm_dsc_get_slice_per_intf() - get number of slices per interface
+ * @dsc: Pointer to drm dsc config struct
+ * @intf_width: interface width
+ * Returns: Integer representing the slice per interface
+ */
+static inline int msm_dsc_get_slice_per_intf(struct drm_dsc_config *dsc, int intf_width)
+{
+	return DIV_ROUND_UP(intf_width, dsc->slice_width);
+}
+
+/**
+ * msm_dsc_get_bytes_per_line() - Calculate bytes per line
+ * @dsc: Pointer to drm dsc config struct
+ * Returns: Integer value representing pclk per interface
+ *
+ * Note: This value will then be passed along to DSI and DP for some more
+ * calculations. This is because DSI and DP divide the pclk_per_intf value
+ * by different values depending on if widebus is enabled.
+ */
+static inline int msm_dsc_get_bytes_per_line(struct drm_dsc_config *dsc)
+{
+	return dsc->slice_count * dsc->slice_chunk_size;
+}
+
+/**
+ * msm_dsc_get_bytes_per_slice() - get size of each slice for dsc
+ * @dsc: Pointer to drm dsc config struct
+ * Returns: s31.32 fixed point value representing bytes per slice
+ */
+s64 msm_dsc_get_bytes_per_slice(struct drm_dsc_config *dsc);
+
+/**
+ * msm_dsc_get_bytes_per_intf() - get total bytes per interface
+ * @dsc: Pointer to drm dsc config struct
+ * @intf_width: interface width
+ * Returns: u32 value representing bytes per interface
+ */
+u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int intf_width);
+
+#endif /* MSM_DSC_HELPER_H_ */