On Tue, 29 Oct 2024 at 16:15, Yongbang Shi <shiyongbang@xxxxxxxxxx> wrote: > > > On Tue, Oct 22, 2024 at 08:41:46PM +0800, Yongbang Shi wrote: > >> From: baihan li <libaihan@xxxxxxxxxx> > >> > >> Add link training process functions in this moduel. > > We should probably have a bounty for a developer who finally writes a > > generic DP link training helpers. > > > >> Signed-off-by: baihan li <libaihan@xxxxxxxxxx> > > Missing SoB > > > >> --- > >> ChangeLog: > >> v1 -> v2: > >> - using drm_dp_* functions implement dp link training process, suggested by Jani Nikula. > >> - fix build errors reported by kernel test robot <lkp@xxxxxxxxx> > >> Closes: https://lore.kernel.org/oe-kbuild-all/202410031735.8iRZZR6T-lkp@xxxxxxxxx/ > >> v1:https://lore.kernel.org/all/20240930100610.782363-1-shiyongbang@xxxxxxxxxx/ > >> --- > >> drivers/gpu/drm/hisilicon/hibmc/Makefile | 2 +- > >> drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c | 344 +++++++++++++++++++ > >> drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.h | 25 ++ > >> 3 files changed, 370 insertions(+), 1 deletion(-) > >> create mode 100644 drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c > >> create mode 100644 drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.h > >> > >> diff --git a/drivers/gpu/drm/hisilicon/hibmc/Makefile b/drivers/gpu/drm/hisilicon/hibmc/Makefile > >> index 8770ec6dfffd..94d77da88bbf 100644 > >> --- a/drivers/gpu/drm/hisilicon/hibmc/Makefile > >> +++ b/drivers/gpu/drm/hisilicon/hibmc/Makefile > >> @@ -1,5 +1,5 @@ > >> # SPDX-License-Identifier: GPL-2.0-only > >> hibmc-drm-y := hibmc_drm_drv.o hibmc_drm_de.o hibmc_drm_vdac.o hibmc_drm_i2c.o \ > >> - dp/dp_aux.o > >> + dp/dp_aux.o dp/dp_link.o > >> > >> obj-$(CONFIG_DRM_HISI_HIBMC) += hibmc-drm.o > >> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c > >> new file mode 100644 > >> index 000000000000..b02a536e0689 > >> --- /dev/null > >> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c > >> @@ -0,0 +1,344 @@ > >> +// SPDX-License-Identifier: GPL-2.0-or-later > >> +// Copyright (c) 2024 Hisilicon Limited. > >> + > >> +#include <linux/delay.h> > >> +#include <drm/drm_device.h> > >> +#include <drm/drm_print.h> > >> +#include "dp_comm.h" > >> +#include "dp_reg.h" > >> +#include "dp_link.h" > >> +#include "dp_aux.h" > >> + > >> +const u8 link_rate_map[] = {DP_LINK_BW_1_62, DP_LINK_BW_2_7, > >> + DP_LINK_BW_5_4, DP_LINK_BW_8_1}; > >> + > >> +static int dp_link_training_configure(struct dp_dev *dp) > >> +{ > >> + u8 buf[2]; > >> + int ret; > >> + > >> + /* DP 2 lane */ > >> + dp_write_bits(dp->base + DP_PHYIF_CTRL0, DP_CFG_LANE_DATA_EN, > >> + dp->link.cap.lanes == DP_LANE_NUM_2 ? 0x3 : 0x1); > >> + dp_write_bits(dp->base + DP_DPTX_GCTL0, DP_CFG_PHY_LANE_NUM, > >> + dp->link.cap.lanes == DP_LANE_NUM_2 ? 0x1 : 0); > >> + > >> + /* enhanced frame */ > >> + dp_write_bits(dp->base + DP_VIDEO_CTRL, DP_CFG_STREAM_FRAME_MODE, 0x1); > >> + > >> + /* set rate and lane count */ > >> + buf[0] = dp_get_link_rate(dp->link.cap.link_rate); > >> + buf[1] = DP_LANE_COUNT_ENHANCED_FRAME_EN | dp->link.cap.lanes; > >> + ret = drm_dp_dpcd_write(&dp->aux, DP_LINK_BW_SET, buf, sizeof(buf)); > >> + if (ret != sizeof(buf)) { > >> + drm_err(dp->dev, "dp aux write link rate and lanes failed, ret: %d\n", ret); > >> + return ret; > >> + } > >> + > >> + /* set 8b/10b and downspread */ > >> + buf[0] = 0x10; > >> + buf[1] = 0x1; > >> + ret = drm_dp_dpcd_write(&dp->aux, DP_DOWNSPREAD_CTRL, buf, sizeof(buf)); > >> + if (ret != sizeof(buf)) > >> + drm_err(dp->dev, "dp aux write 8b/10b and downspread failed, ret: %d\n", ret); > >> + > >> + ret = drm_dp_read_dpcd_caps(&dp->aux, dp->dpcd); > >> + if (ret) > >> + drm_err(dp->dev, "dp aux read dpcd failed, ret: %d\n", ret); > >> + > >> + return ret; > >> +} > >> + > >> +static int dp_link_pattern2dpcd(struct dp_dev *dp, enum dp_pattern_e pattern) > >> +{ > >> + switch (pattern) { > >> + case DP_PATTERN_NO: > >> + return DP_TRAINING_PATTERN_DISABLE; > >> + case DP_PATTERN_TPS1: > >> + return DP_TRAINING_PATTERN_1; > >> + case DP_PATTERN_TPS2: > >> + return DP_TRAINING_PATTERN_2; > >> + case DP_PATTERN_TPS3: > >> + return DP_TRAINING_PATTERN_3; > >> + case DP_PATTERN_TPS4: > >> + return DP_TRAINING_PATTERN_4; > >> + default: > >> + drm_err(dp->dev, "dp link unknown pattern %d\n", pattern); > >> + return -EINVAL; > > Why do you need the extra defines / wrappers? Can you use > > DP_TRAINING_PATTERN_foo directly? > > Hi Dmitry, > Thanks for your all of these good advices and questions. I will resply as soon as possible. > For this point, I also need this enum dp_pattern_e value to write in my dp reg at TPS stage, so I made this map here. I'd suggest to do it other way around: use standard defines and when necessary map them for the register write. -- With best wishes Dmitry
