| Message ID | 20230329-rfc-msm-dsc-helper-v4-1-1b79c78b30d7@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce MSM-specific DSC helpers | expand |
On 05/04/2023 03:41, Jessica Zhang wrote: > 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 > > Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> > --- > drivers/gpu/drm/msm/Makefile | 1 + > drivers/gpu/drm/msm/msm_dsc_helper.c | 47 ++++++++++++++++++++++++ > drivers/gpu/drm/msm/msm_dsc_helper.h | 70 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 118 insertions(+) > > 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..0539221eb09d > --- /dev/null > +++ b/drivers/gpu/drm/msm/msm_dsc_helper.c > @@ -0,0 +1,47 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved > + */ > + > +#include <linux/kernel.h> > +#include <linux/errno.h> > +#include <drm/drm_fixed.h> > + > +#include "msm_drv.h" > +#include "msm_dsc_helper.h" > + > +s64 get_bytes_per_soft_slice(struct drm_dsc_config *dsc) > +{ > + int bpp = msm_dsc_get_bpp_int(dsc); > + s64 numerator_fp, denominator_fp; > + s64 comp_ratio_fp = drm_fixp_from_fraction(dsc->bits_per_component * 3, bpp); > + > + numerator_fp = drm_int2fixp(dsc->slice_width * 3 * dsc->bits_per_component); > + denominator_fp = drm_fixp_mul(comp_ratio_fp, drm_int2fixp(8)); > + > + return drm_fixp_div(numerator_fp, denominator_fp); If we remove 3 * dsc->bits_per_components from both numerator and denominator, this whole function seems to be as simple as DIV_ROUND_UP(dsc->slice_width * bpp, 8) Or, if you prefer FP math, drm_fixp_from_fraction(dsc->slice_width * bpp, 8). > +} > + > +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int intf_width) > +{ > + u32 bytes_per_soft_slice, bytes_per_intf; > + s64 bytes_per_soft_slice_fp; > + int slice_per_intf = msm_dsc_get_slice_per_intf(dsc, intf_width); > + > + bytes_per_soft_slice_fp = get_bytes_per_soft_slice(dsc); > + bytes_per_soft_slice = drm_fixp2int_ceil(bytes_per_soft_slice_fp); > + > + bytes_per_intf = bytes_per_soft_slice * slice_per_intf; > + > + return bytes_per_intf; > +} > + > +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc) > +{ > + s64 data_width; > + > + data_width = drm_fixp_mul(drm_int2fixp(dsc->slice_count), > + get_bytes_per_soft_slice(dsc)); And this is then DIV_ROUND_UP(dsc->slice_width * dsc->slice_count * bpp, 8) > + > + return drm_fixp2int_ceil(data_width); > +} > 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..31116a31090f > --- /dev/null > +++ b/drivers/gpu/drm/msm/msm_dsc_helper.h > @@ -0,0 +1,70 @@ > +/* 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 <drm/display/drm_dsc_helper.h> > +#include <drm/drm_modes.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 > + */ > +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 > + */ > +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 > + */ > +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); > +} > + > +/** > + * get_bytes_per_soft_slice - get size of each soft slice for dsc > + * @dsc: Pointer to drm dsc config struct > + */ > +s64 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 > + */ > +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int intf_width); > + > +/** > + * msm_dsc_get_pclk_per_intf - Calculate pclk per interface. > + * @dsc: Pointer to drm dsc config struct > + * > + * 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. > + */ > +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc); empty line, please > +#endif /* MSM_DSC_HELPER_H_ */ >
On 4/5/2023 12:26 PM, Dmitry Baryshkov wrote: > On 05/04/2023 03:41, Jessica Zhang wrote: >> 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 >> >> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> >> --- >> drivers/gpu/drm/msm/Makefile | 1 + >> drivers/gpu/drm/msm/msm_dsc_helper.c | 47 ++++++++++++++++++++++++ >> drivers/gpu/drm/msm/msm_dsc_helper.h | 70 >> ++++++++++++++++++++++++++++++++++++ >> 3 files changed, 118 insertions(+) >> >> 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..0539221eb09d >> --- /dev/null >> +++ b/drivers/gpu/drm/msm/msm_dsc_helper.c >> @@ -0,0 +1,47 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights >> reserved >> + */ >> + >> +#include <linux/kernel.h> >> +#include <linux/errno.h> >> +#include <drm/drm_fixed.h> >> + >> +#include "msm_drv.h" >> +#include "msm_dsc_helper.h" >> + >> +s64 get_bytes_per_soft_slice(struct drm_dsc_config *dsc) >> +{ >> + int bpp = msm_dsc_get_bpp_int(dsc); >> + s64 numerator_fp, denominator_fp; >> + s64 comp_ratio_fp = >> drm_fixp_from_fraction(dsc->bits_per_component * 3, bpp); >> + >> + numerator_fp = drm_int2fixp(dsc->slice_width * 3 * >> dsc->bits_per_component); >> + denominator_fp = drm_fixp_mul(comp_ratio_fp, drm_int2fixp(8)); >> + >> + return drm_fixp_div(numerator_fp, denominator_fp); > > If we remove 3 * dsc->bits_per_components from both numerator and > denominator, this whole function seems to be as simple as > DIV_ROUND_UP(dsc->slice_width * bpp, 8) > > Or, if you prefer FP math, drm_fixp_from_fraction(dsc->slice_width * > bpp, 8). Hi Dmitry, Sounds good. > >> +} >> + >> +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int >> intf_width) >> +{ >> + u32 bytes_per_soft_slice, bytes_per_intf; >> + s64 bytes_per_soft_slice_fp; >> + int slice_per_intf = msm_dsc_get_slice_per_intf(dsc, intf_width); >> + >> + bytes_per_soft_slice_fp = get_bytes_per_soft_slice(dsc); >> + bytes_per_soft_slice = drm_fixp2int_ceil(bytes_per_soft_slice_fp); >> + >> + bytes_per_intf = bytes_per_soft_slice * slice_per_intf; >> + >> + return bytes_per_intf; >> +} >> + >> +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc) >> +{ >> + s64 data_width; >> + >> + data_width = drm_fixp_mul(drm_int2fixp(dsc->slice_count), >> + get_bytes_per_soft_slice(dsc)); > > And this is then DIV_ROUND_UP(dsc->slice_width * dsc->slice_count * bpp, 8) I would prefer to keep the FP math/get_bytes_per_soft_slice() call here and leave the ceil() until the end. > >> + >> + return drm_fixp2int_ceil(data_width); >> +} >> 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..31116a31090f >> --- /dev/null >> +++ b/drivers/gpu/drm/msm/msm_dsc_helper.h >> @@ -0,0 +1,70 @@ >> +/* 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 <drm/display/drm_dsc_helper.h> >> +#include <drm/drm_modes.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 >> + */ >> +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 >> + */ >> +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 >> + */ >> +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); >> +} >> + >> +/** >> + * get_bytes_per_soft_slice - get size of each soft slice for dsc >> + * @dsc: Pointer to drm dsc config struct >> + */ >> +s64 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 >> + */ >> +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int >> intf_width); >> + >> +/** >> + * msm_dsc_get_pclk_per_intf - Calculate pclk per interface. >> + * @dsc: Pointer to drm dsc config struct >> + * >> + * 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. >> + */ >> +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc); > > empty line, please Acked. Thanks, Jessica Zhang > >> +#endif /* MSM_DSC_HELPER_H_ */ >> > > -- > With best wishes > Dmitry >
On 06/04/2023 01:02, Jessica Zhang wrote: > > > On 4/5/2023 12:26 PM, Dmitry Baryshkov wrote: >> On 05/04/2023 03:41, Jessica Zhang wrote: >>> 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 >>> >>> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> >>> --- >>> drivers/gpu/drm/msm/Makefile | 1 + >>> drivers/gpu/drm/msm/msm_dsc_helper.c | 47 ++++++++++++++++++++++++ >>> drivers/gpu/drm/msm/msm_dsc_helper.h | 70 >>> ++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 118 insertions(+) >>> >>> 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..0539221eb09d >>> --- /dev/null >>> +++ b/drivers/gpu/drm/msm/msm_dsc_helper.c >>> @@ -0,0 +1,47 @@ >>> +// SPDX-License-Identifier: GPL-2.0-only >>> +/* >>> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights >>> reserved >>> + */ >>> + >>> +#include <linux/kernel.h> >>> +#include <linux/errno.h> >>> +#include <drm/drm_fixed.h> >>> + >>> +#include "msm_drv.h" >>> +#include "msm_dsc_helper.h" >>> + >>> +s64 get_bytes_per_soft_slice(struct drm_dsc_config *dsc) >>> +{ >>> + int bpp = msm_dsc_get_bpp_int(dsc); >>> + s64 numerator_fp, denominator_fp; >>> + s64 comp_ratio_fp = >>> drm_fixp_from_fraction(dsc->bits_per_component * 3, bpp); >>> + >>> + numerator_fp = drm_int2fixp(dsc->slice_width * 3 * >>> dsc->bits_per_component); >>> + denominator_fp = drm_fixp_mul(comp_ratio_fp, drm_int2fixp(8)); >>> + >>> + return drm_fixp_div(numerator_fp, denominator_fp); >> >> If we remove 3 * dsc->bits_per_components from both numerator and >> denominator, this whole function seems to be as simple as >> DIV_ROUND_UP(dsc->slice_width * bpp, 8) >> >> Or, if you prefer FP math, drm_fixp_from_fraction(dsc->slice_width * >> bpp, 8). > > Hi Dmitry, > > Sounds good. > >> >>> +} >>> + >>> +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int >>> intf_width) >>> +{ >>> + u32 bytes_per_soft_slice, bytes_per_intf; >>> + s64 bytes_per_soft_slice_fp; >>> + int slice_per_intf = msm_dsc_get_slice_per_intf(dsc, intf_width); >>> + >>> + bytes_per_soft_slice_fp = get_bytes_per_soft_slice(dsc); >>> + bytes_per_soft_slice = drm_fixp2int_ceil(bytes_per_soft_slice_fp); >>> + >>> + bytes_per_intf = bytes_per_soft_slice * slice_per_intf; >>> + >>> + return bytes_per_intf; >>> +} >>> + >>> +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc) >>> +{ >>> + s64 data_width; >>> + >>> + data_width = drm_fixp_mul(drm_int2fixp(dsc->slice_count), >>> + get_bytes_per_soft_slice(dsc)); >> >> And this is then DIV_ROUND_UP(dsc->slice_width * dsc->slice_count * >> bpp, 8) > > I would prefer to keep the FP math/get_bytes_per_soft_slice() call here > and leave the ceil() until the end. It is the code, you are calling ceil right after drm_fixp_mul. So, there is no difference. > >> >>> + >>> + return drm_fixp2int_ceil(data_width); >>> +} >>> 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..31116a31090f >>> --- /dev/null >>> +++ b/drivers/gpu/drm/msm/msm_dsc_helper.h >>> @@ -0,0 +1,70 @@ >>> +/* 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 <drm/display/drm_dsc_helper.h> >>> +#include <drm/drm_modes.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 >>> + */ >>> +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 >>> + */ >>> +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 >>> + */ >>> +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); >>> +} >>> + >>> +/** >>> + * get_bytes_per_soft_slice - get size of each soft slice for dsc >>> + * @dsc: Pointer to drm dsc config struct >>> + */ >>> +s64 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 >>> + */ >>> +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int >>> intf_width); >>> + >>> +/** >>> + * msm_dsc_get_pclk_per_intf - Calculate pclk per interface. >>> + * @dsc: Pointer to drm dsc config struct >>> + * >>> + * 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. >>> + */ >>> +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc); >> >> empty line, please > > Acked. > > Thanks, > > Jessica Zhang > >> >>> +#endif /* MSM_DSC_HELPER_H_ */ >>> >> >> -- >> With best wishes >> Dmitry >>
On 4/5/2023 12:26 PM, Dmitry Baryshkov wrote: > On 05/04/2023 03:41, Jessica Zhang wrote: >> 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 >> >> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> >> --- >> drivers/gpu/drm/msm/Makefile | 1 + >> drivers/gpu/drm/msm/msm_dsc_helper.c | 47 ++++++++++++++++++++++++ >> drivers/gpu/drm/msm/msm_dsc_helper.h | 70 >> ++++++++++++++++++++++++++++++++++++ >> 3 files changed, 118 insertions(+) >> >> 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..0539221eb09d >> --- /dev/null >> +++ b/drivers/gpu/drm/msm/msm_dsc_helper.c >> @@ -0,0 +1,47 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights >> reserved >> + */ >> + >> +#include <linux/kernel.h> >> +#include <linux/errno.h> >> +#include <drm/drm_fixed.h> >> + >> +#include "msm_drv.h" >> +#include "msm_dsc_helper.h" >> + >> +s64 get_bytes_per_soft_slice(struct drm_dsc_config *dsc) >> +{ >> + int bpp = msm_dsc_get_bpp_int(dsc); >> + s64 numerator_fp, denominator_fp; >> + s64 comp_ratio_fp = >> drm_fixp_from_fraction(dsc->bits_per_component * 3, bpp); >> + >> + numerator_fp = drm_int2fixp(dsc->slice_width * 3 * >> dsc->bits_per_component); >> + denominator_fp = drm_fixp_mul(comp_ratio_fp, drm_int2fixp(8)); >> + >> + return drm_fixp_div(numerator_fp, denominator_fp); > > If we remove 3 * dsc->bits_per_components from both numerator and > denominator, this whole function seems to be as simple as > DIV_ROUND_UP(dsc->slice_width * bpp, 8) > > Or, if you prefer FP math, drm_fixp_from_fraction(dsc->slice_width * > bpp, 8). > True and thats not really surprising because bytes_per_soft_slice is eventually (dsc->slice_width * bpp, 8) I also thought about it after you mentioned that they will cancel out then why was downstream code and our programming guide doing this way. So i thought a bit more and the reason from what I can see is that its showing that compression ratio was factored into the math while calculating it. If we just go with (dsc->slice_width * bpp, 8), it does not really show that this was actually compressed bytes per slice leading to the earlier confusion that it was uncompressed pclk while it actually was. >> +} >> + >> +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int >> intf_width) >> +{ >> + u32 bytes_per_soft_slice, bytes_per_intf; >> + s64 bytes_per_soft_slice_fp; >> + int slice_per_intf = msm_dsc_get_slice_per_intf(dsc, intf_width); >> + >> + bytes_per_soft_slice_fp = get_bytes_per_soft_slice(dsc); >> + bytes_per_soft_slice = drm_fixp2int_ceil(bytes_per_soft_slice_fp); >> + >> + bytes_per_intf = bytes_per_soft_slice * slice_per_intf; >> + >> + return bytes_per_intf; >> +} >> + >> +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc) >> +{ >> + s64 data_width; >> + >> + data_width = drm_fixp_mul(drm_int2fixp(dsc->slice_count), >> + get_bytes_per_soft_slice(dsc)); > > And this is then DIV_ROUND_UP(dsc->slice_width * dsc->slice_count * bpp, 8) > >> + >> + return drm_fixp2int_ceil(data_width); >> +} >> 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..31116a31090f >> --- /dev/null >> +++ b/drivers/gpu/drm/msm/msm_dsc_helper.h >> @@ -0,0 +1,70 @@ >> +/* 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 <drm/display/drm_dsc_helper.h> >> +#include <drm/drm_modes.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 >> + */ >> +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 >> + */ >> +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 >> + */ >> +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); >> +} >> + >> +/** >> + * get_bytes_per_soft_slice - get size of each soft slice for dsc >> + * @dsc: Pointer to drm dsc config struct >> + */ >> +s64 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 >> + */ >> +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int >> intf_width); >> + >> +/** >> + * msm_dsc_get_pclk_per_intf - Calculate pclk per interface. >> + * @dsc: Pointer to drm dsc config struct >> + * >> + * 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. >> + */ >> +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc); > > empty line, please > >> +#endif /* MSM_DSC_HELPER_H_ */ >> >
On 06/04/2023 02:34, Abhinav Kumar wrote: > > > On 4/5/2023 12:26 PM, Dmitry Baryshkov wrote: >> On 05/04/2023 03:41, Jessica Zhang wrote: >>> 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 >>> >>> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> >>> --- >>> drivers/gpu/drm/msm/Makefile | 1 + >>> drivers/gpu/drm/msm/msm_dsc_helper.c | 47 ++++++++++++++++++++++++ >>> drivers/gpu/drm/msm/msm_dsc_helper.h | 70 >>> ++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 118 insertions(+) >>> >>> 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..0539221eb09d >>> --- /dev/null >>> +++ b/drivers/gpu/drm/msm/msm_dsc_helper.c >>> @@ -0,0 +1,47 @@ >>> +// SPDX-License-Identifier: GPL-2.0-only >>> +/* >>> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights >>> reserved >>> + */ >>> + >>> +#include <linux/kernel.h> >>> +#include <linux/errno.h> >>> +#include <drm/drm_fixed.h> >>> + >>> +#include "msm_drv.h" >>> +#include "msm_dsc_helper.h" >>> + >>> +s64 get_bytes_per_soft_slice(struct drm_dsc_config *dsc) >>> +{ >>> + int bpp = msm_dsc_get_bpp_int(dsc); >>> + s64 numerator_fp, denominator_fp; >>> + s64 comp_ratio_fp = >>> drm_fixp_from_fraction(dsc->bits_per_component * 3, bpp); >>> + >>> + numerator_fp = drm_int2fixp(dsc->slice_width * 3 * >>> dsc->bits_per_component); >>> + denominator_fp = drm_fixp_mul(comp_ratio_fp, drm_int2fixp(8)); >>> + >>> + return drm_fixp_div(numerator_fp, denominator_fp); >> >> If we remove 3 * dsc->bits_per_components from both numerator and >> denominator, this whole function seems to be as simple as >> DIV_ROUND_UP(dsc->slice_width * bpp, 8) >> >> Or, if you prefer FP math, drm_fixp_from_fraction(dsc->slice_width * >> bpp, 8). >> > > True and thats not really surprising because bytes_per_soft_slice is > eventually (dsc->slice_width * bpp, 8) > > I also thought about it after you mentioned that they will cancel out > then why was downstream code and our programming guide doing this way. > > So i thought a bit more and the reason from what I can see is that its > showing that compression ratio was factored into the math while > calculating it. If we just go with (dsc->slice_width * bpp, 8), it does > not really show that this was actually compressed bytes per slice > leading to the earlier confusion that it was uncompressed pclk while it > actually was. I'd say, name we can name that dsc_bpp or compressed_bpp instead of just bpp, this way showing that it is a compressed pclk. But please don't complicate the math. > >>> +} >>> + >>> +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int >>> intf_width) >>> +{ >>> + u32 bytes_per_soft_slice, bytes_per_intf; >>> + s64 bytes_per_soft_slice_fp; >>> + int slice_per_intf = msm_dsc_get_slice_per_intf(dsc, intf_width); >>> + >>> + bytes_per_soft_slice_fp = get_bytes_per_soft_slice(dsc); >>> + bytes_per_soft_slice = drm_fixp2int_ceil(bytes_per_soft_slice_fp); >>> + >>> + bytes_per_intf = bytes_per_soft_slice * slice_per_intf; >>> + >>> + return bytes_per_intf; >>> +} >>> + >>> +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc) >>> +{ >>> + s64 data_width; >>> + >>> + data_width = drm_fixp_mul(drm_int2fixp(dsc->slice_count), >>> + get_bytes_per_soft_slice(dsc)); >> >> And this is then DIV_ROUND_UP(dsc->slice_width * dsc->slice_count * >> bpp, 8) >> >>> + >>> + return drm_fixp2int_ceil(data_width); >>> +} >>> 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..31116a31090f >>> --- /dev/null >>> +++ b/drivers/gpu/drm/msm/msm_dsc_helper.h >>> @@ -0,0 +1,70 @@ >>> +/* 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 <drm/display/drm_dsc_helper.h> >>> +#include <drm/drm_modes.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 >>> + */ >>> +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 >>> + */ >>> +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 >>> + */ >>> +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); >>> +} >>> + >>> +/** >>> + * get_bytes_per_soft_slice - get size of each soft slice for dsc >>> + * @dsc: Pointer to drm dsc config struct >>> + */ >>> +s64 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 >>> + */ >>> +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int >>> intf_width); >>> + >>> +/** >>> + * msm_dsc_get_pclk_per_intf - Calculate pclk per interface. >>> + * @dsc: Pointer to drm dsc config struct >>> + * >>> + * 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. >>> + */ >>> +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc); >> >> empty line, please >> >>> +#endif /* MSM_DSC_HELPER_H_ */ >>> >>
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..0539221eb09d --- /dev/null +++ b/drivers/gpu/drm/msm/msm_dsc_helper.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved + */ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <drm/drm_fixed.h> + +#include "msm_drv.h" +#include "msm_dsc_helper.h" + +s64 get_bytes_per_soft_slice(struct drm_dsc_config *dsc) +{ + int bpp = msm_dsc_get_bpp_int(dsc); + s64 numerator_fp, denominator_fp; + s64 comp_ratio_fp = drm_fixp_from_fraction(dsc->bits_per_component * 3, bpp); + + numerator_fp = drm_int2fixp(dsc->slice_width * 3 * dsc->bits_per_component); + denominator_fp = drm_fixp_mul(comp_ratio_fp, drm_int2fixp(8)); + + return drm_fixp_div(numerator_fp, denominator_fp); +} + +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int intf_width) +{ + u32 bytes_per_soft_slice, bytes_per_intf; + s64 bytes_per_soft_slice_fp; + int slice_per_intf = msm_dsc_get_slice_per_intf(dsc, intf_width); + + bytes_per_soft_slice_fp = get_bytes_per_soft_slice(dsc); + bytes_per_soft_slice = drm_fixp2int_ceil(bytes_per_soft_slice_fp); + + bytes_per_intf = bytes_per_soft_slice * slice_per_intf; + + return bytes_per_intf; +} + +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc) +{ + s64 data_width; + + data_width = drm_fixp_mul(drm_int2fixp(dsc->slice_count), + get_bytes_per_soft_slice(dsc)); + + return drm_fixp2int_ceil(data_width); +} 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..31116a31090f --- /dev/null +++ b/drivers/gpu/drm/msm/msm_dsc_helper.h @@ -0,0 +1,70 @@ +/* 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 <drm/display/drm_dsc_helper.h> +#include <drm/drm_modes.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 + */ +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 + */ +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 + */ +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); +} + +/** + * get_bytes_per_soft_slice - get size of each soft slice for dsc + * @dsc: Pointer to drm dsc config struct + */ +s64 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 + */ +u32 msm_dsc_get_bytes_per_intf(struct drm_dsc_config *dsc, int intf_width); + +/** + * msm_dsc_get_pclk_per_intf - Calculate pclk per interface. + * @dsc: Pointer to drm dsc config struct + * + * 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. + */ +int msm_dsc_get_pclk_per_intf(struct drm_dsc_config *dsc); +#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 Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> --- drivers/gpu/drm/msm/Makefile | 1 + drivers/gpu/drm/msm/msm_dsc_helper.c | 47 ++++++++++++++++++++++++ drivers/gpu/drm/msm/msm_dsc_helper.h | 70 ++++++++++++++++++++++++++++++++++++ 3 files changed, 118 insertions(+)