@@ -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 \
new file mode 100644
@@ -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_soft_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_soft_slice;
+ s64 bytes_per_soft_slice_fp;
+ int slice_per_intf = msm_dsc_get_slice_per_intf(dsc, intf_width);
+
+ bytes_per_soft_slice_fp = msm_dsc_get_bytes_per_soft_slice(dsc);
+ bytes_per_soft_slice = drm_fixp2int_ceil(bytes_per_soft_slice_fp);
+
+ return bytes_per_soft_slice * slice_per_intf;
+}
new file mode 100644
@@ -0,0 +1,81 @@
+/* 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_dce_bytes_per_line - get bytes per line to help calculate data width
+ * when configuring the timing engine
+ * @dsc: Pointer to drm dsc config struct
+ * @intf_width: interface width
+ * Returns: u32 value representing the bytes per line
+ */
+static inline u32 msm_dsc_get_dce_bytes_per_line(struct drm_dsc_config *dsc, int intf_width)
+{
+ return DIV_ROUND_UP(msm_dsc_get_bpp_int(dsc) * intf_width, 8);
+}
+
+/**
+ * msm_dsc_get_pclk_per_intf - Calculate pclk per interface.
+ * @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_pclk_per_intf(struct drm_dsc_config *dsc)
+{
+ return DIV_ROUND_UP(dsc->slice_width * dsc->slice_count * msm_dsc_get_bpp_int(dsc), 8);
+}
+
+/**
+ * msm_dsc_get_bytes_per_soft_slice - get size of each soft slice for dsc
+ * @dsc: Pointer to drm dsc config struct
+ * Returns: s31.32 fixed point value representing bytes per soft slice
+ */
+s64 msm_dsc_get_bytes_per_soft_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_ */
Introduce MSM-specific DSC helper methods, as some calculations are common between DP and DSC. Changes in v2: - Moved files up to msm/ directory - Dropped get_comp_ratio() helper - Used drm_int2fixp() to convert to integers to fp - Style changes to improve readability - Dropped unused bpp variable in msm_dsc_get_dce_bytes_per_line() - Changed msm_dsc_get_slice_per_intf() to a static inline method - Dropped last division step of msm_dsc_get_pclk_per_line() and changed method name accordingly - Changed DSC_BPP macro to drm_dsc_get_bpp_int() helper method - Fixed some math issues caused by passing in incorrect types to drm_fixed methods in get_bytes_per_soft_slice() Changes in v3: - Dropped src_bpp parameter from all methods -- src_bpp can be calculated as dsc->bits_per_component * 3 - Dropped intf_width parameter from get_bytes_per_soft_slice() - Moved dsc->bits_per_component to numerator calculation in get_bytes_per_soft_slice() - Renamed msm_dsc_get_uncompressed_pclk_per_line to *_get_uncompressed_pclk_per_intf() - Removed dsc->slice_width check from msm_dsc_get_uncompressed_pclk_per_intf() - Made get_bytes_per_soft_slice() a public method (this will be called later to help calculate DP pclk params) - Added documentation in comments - Moved extra_eol_bytes math out of msm_dsc_get_eol_byte_num() and renamed msm_dsc_get_eol_byte_num to *_get_bytes_per_intf. Changes in v4: - Changed msm_dsc_get_uncompressed_pclk_per_intf to msm_dsc_get_pclk_per_intf Changes in v5: - Added extra line at end of msm_dsc_helper.h - Simplified msm_dsc_get_bytes_per_soft_slice() math - Simplified and inlined msm_dsc_get_pclk_per_intf() math - Removed unused headers Changes in v6: - Documented return value for all helper functions - Fixed dependency issue caused by drm_fixed.h being included before linux/kernel.h Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> --- drivers/gpu/drm/msm/Makefile | 1 + drivers/gpu/drm/msm/msm_dsc_helper.c | 26 ++++++++++++ drivers/gpu/drm/msm/msm_dsc_helper.h | 81 ++++++++++++++++++++++++++++++++++++ 3 files changed, 108 insertions(+)