From f21e5fa191be05616e3250723c5c4cadc9baf84a Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Tue, 23 Nov 2021 18:18:00 +1000 Subject: [PATCH] drm/nouveau/disp/dp: add support for lttprs Add support for Link-Training Tunable PHY Repeaters, required to support higher bit rates on longer cables, as well as USB-C on certain docks and laptops. Signed-off-by: Ben Skeggs Reviewed-by: Lyude Paul Signed-off-by: Karol Herbst Link: https://gitlab.freedesktop.org/drm/nouveau/-/merge_requests/17 --- drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c | 114 ++++++++++++++++-- drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.h | 12 ++ 2 files changed, 114 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c index eee2451123c9..b0dfa08f799a 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c +++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c @@ -41,6 +41,10 @@ struct lt_state { struct nvkm_dp *dp; + + int repeaters; + int repeater; + u8 stat[6]; u8 conf[4]; bool pc2; @@ -52,11 +56,26 @@ static int nvkm_dp_train_sense(struct lt_state *lt, bool pc, u32 delay) { struct nvkm_dp *dp = lt->dp; + u32 addr; int ret; usleep_range(delay, delay * 2); - ret = nvkm_rdaux(dp->aux, DPCD_LS02, lt->stat, 6); + if (lt->repeater) + addr = DPCD_LTTPR_LANE0_1_STATUS(lt->repeater); + else + addr = DPCD_LS02; + + ret = nvkm_rdaux(dp->aux, addr, <->stat[0], 3); + if (ret) + return ret; + + if (lt->repeater) + addr = DPCD_LTTPR_LANE0_1_ADJUST(lt->repeater); + else + addr = DPCD_LS06; + + ret = nvkm_rdaux(dp->aux, addr, <->stat[4], 2); if (ret) return ret; @@ -82,6 +101,7 @@ nvkm_dp_train_drive(struct lt_state *lt, bool pc) struct nvbios_dpout info; struct nvbios_dpcfg ocfg; u8 ver, hdr, cnt, len; + u32 addr; u32 data; int ret, i; @@ -110,6 +130,9 @@ nvkm_dp_train_drive(struct lt_state *lt, bool pc) OUTP_TRACE(&dp->outp, "config lane %d %02x %02x", i, lt->conf[i], lpc2); + if (lt->repeater != lt->repeaters) + continue; + data = nvbios_dpout_match(bios, dp->outp.info.hasht, dp->outp.info.hashm, &ver, &hdr, &cnt, &len, &info); @@ -126,7 +149,12 @@ nvkm_dp_train_drive(struct lt_state *lt, bool pc) ocfg.pe, ocfg.tx_pu); } - ret = nvkm_wraux(dp->aux, DPCD_LC03(0), lt->conf, 4); + if (lt->repeater) + addr = DPCD_LTTPR_LANE0_SET(lt->repeater); + else + addr = DPCD_LC03(0); + + ret = nvkm_wraux(dp->aux, addr, lt->conf, 4); if (ret) return ret; @@ -143,12 +171,18 @@ static void nvkm_dp_train_pattern(struct lt_state *lt, u8 pattern) { struct nvkm_dp *dp = lt->dp; + u32 addr; u8 sink_tp; OUTP_TRACE(&dp->outp, "training pattern %d", pattern); dp->outp.ior->func->dp.pattern(dp->outp.ior, pattern); - nvkm_rdaux(dp->aux, DPCD_LC02, &sink_tp, 1); + if (lt->repeater) + addr = DPCD_LTTPR_PATTERN_SET(lt->repeater); + else + addr = DPCD_LC02; + + nvkm_rdaux(dp->aux, addr, &sink_tp, 1); sink_tp &= ~DPCD_LC02_TRAINING_PATTERN_SET; sink_tp |= (pattern != 4) ? pattern : 7; @@ -156,16 +190,23 @@ nvkm_dp_train_pattern(struct lt_state *lt, u8 pattern) sink_tp |= DPCD_LC02_SCRAMBLING_DISABLE; else sink_tp &= ~DPCD_LC02_SCRAMBLING_DISABLE; - nvkm_wraux(dp->aux, DPCD_LC02, &sink_tp, 1); + nvkm_wraux(dp->aux, addr, &sink_tp, 1); } static int nvkm_dp_train_eq(struct lt_state *lt) { + struct nvkm_i2c_aux *aux = lt->dp->aux; bool eq_done = false, cr_done = true; int tries = 0, usec = 0, i; + u8 data; - { + if (lt->repeater) { + if (!nvkm_rdaux(aux, DPCD_LTTPR_AUX_RD_INTERVAL(lt->repeater), &data, sizeof(data))) + usec = (data & DPCD_RC0E_AUX_RD_INTERVAL) * 4000; + + nvkm_dp_train_pattern(lt, 4); + } else { if (lt->dp->dpcd[DPCD_RC00_DPCD_REV] >= 0x14 && lt->dp->dpcd[DPCD_RC03] & DPCD_RC03_TPS4_SUPPORTED) nvkm_dp_train_pattern(lt, 4); @@ -208,7 +249,7 @@ nvkm_dp_train_cr(struct lt_state *lt) nvkm_dp_train_pattern(lt, 1); - if (lt->dp->dpcd[DPCD_RC00_DPCD_REV] < 0x14) + if (lt->dp->dpcd[DPCD_RC00_DPCD_REV] < 0x14 && !lt->repeater) usec = (lt->dp->dpcd[DPCD_RC0E] & DPCD_RC0E_AUX_RD_INTERVAL) * 4000; do { @@ -247,7 +288,7 @@ nvkm_dp_train_links(struct nvkm_dp *dp) .dp = dp, }; u32 lnkcmp; - u8 sink[2]; + u8 sink[2], data; int ret; OUTP_DBG(&dp->outp, "training %d x %d MB/s", @@ -303,6 +344,20 @@ nvkm_dp_train_links(struct nvkm_dp *dp) ior->func->dp.power(ior, ior->dp.nr); + /* Select LTTPR non-transparent mode if we have a valid configuration, + * use transparent mode otherwise. + */ + if (dp->lttpr[0] >= 0x14) { + data = DPCD_LTTPR_MODE_TRANSPARENT; + nvkm_wraux(dp->aux, DPCD_LTTPR_MODE, &data, sizeof(data)); + + if (dp->lttprs) { + data = DPCD_LTTPR_MODE_NON_TRANSPARENT; + nvkm_wraux(dp->aux, DPCD_LTTPR_MODE, &data, sizeof(data)); + lt.repeaters = dp->lttprs; + } + } + /* Set desired link configuration on the sink. */ sink[0] = ior->dp.bw; sink[1] = ior->dp.nr; @@ -314,11 +369,19 @@ nvkm_dp_train_links(struct nvkm_dp *dp) return ret; /* Attempt to train the link in this configuration. */ - memset(lt.stat, 0x00, sizeof(lt.stat)); - ret = nvkm_dp_train_cr(<); - if (ret == 0) - ret = nvkm_dp_train_eq(<); - nvkm_dp_train_pattern(<, 0); + for (lt.repeater = lt.repeaters; lt.repeater >= 0; lt.repeater--) { + if (lt.repeater) + OUTP_DBG(&dp->outp, "training LTTPR%d", lt.repeater); + else + OUTP_DBG(&dp->outp, "training sink"); + + memset(lt.stat, 0x00, sizeof(lt.stat)); + ret = nvkm_dp_train_cr(<); + if (ret == 0) + ret = nvkm_dp_train_eq(<); + nvkm_dp_train_pattern(<, 0); + } + return ret; } @@ -501,6 +564,29 @@ nvkm_dp_enable(struct nvkm_dp *dp, bool enable) dp->present = true; } + /* Detect any LTTPRs before reading DPCD receiver caps. */ + if (!nvkm_rdaux(aux, DPCD_LTTPR_REV, dp->lttpr, sizeof(dp->lttpr)) && + dp->lttpr[0] >= 0x14 && dp->lttpr[2]) { + switch (dp->lttpr[2]) { + case 0x80: dp->lttprs = 1; break; + case 0x40: dp->lttprs = 2; break; + case 0x20: dp->lttprs = 3; break; + case 0x10: dp->lttprs = 4; break; + case 0x08: dp->lttprs = 5; break; + case 0x04: dp->lttprs = 6; break; + case 0x02: dp->lttprs = 7; break; + case 0x01: dp->lttprs = 8; break; + default: + /* Unknown LTTPR count, we'll switch to transparent mode. */ + WARN_ON(1); + dp->lttprs = 0; + break; + } + } else { + /* No LTTPR support, or zero LTTPR count - don't touch it at all. */ + memset(dp->lttpr, 0x00, sizeof(dp->lttpr)); + } + if (!nvkm_rdaux(aux, DPCD_RC00_DPCD_REV, dp->dpcd, sizeof(dp->dpcd))) { const u8 rates[] = { 0x14, 0x0a, 0x06, 0 }; const u8 *rate; @@ -509,9 +595,13 @@ nvkm_dp_enable(struct nvkm_dp *dp, bool enable) dp->rates = 0; dp->links = dp->dpcd[DPCD_RC02] & DPCD_RC02_MAX_LANE_COUNT; dp->links = min(dp->links, dp->outp.info.dpconf.link_nr); + if (dp->lttprs && dp->lttpr[4]) + dp->links = min_t(int, dp->links, dp->lttpr[4]); rate_max = dp->dpcd[DPCD_RC01_MAX_LINK_RATE]; rate_max = min(rate_max, dp->outp.info.dpconf.link_bw); + if (dp->lttprs && dp->lttpr[1]) + rate_max = min_t(int, rate_max, dp->lttpr[1]); if (1) { for (rate = rates; *rate; rate++) { diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.h b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.h index 104f847b5abf..8728d5e0fb8a 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.h +++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.h @@ -18,6 +18,8 @@ struct nvkm_dp { struct nvkm_notify hpd; bool present; + u8 lttpr[6]; + u8 lttprs; u8 dpcd[16]; struct { @@ -114,4 +116,14 @@ void nvkm_dp_disable(struct nvkm_outp *, struct nvkm_ior *); #define DPCD_SC00_SET_POWER 0x03 #define DPCD_SC00_SET_POWER_D0 0x01 #define DPCD_SC00_SET_POWER_D3 0x03 + +#define DPCD_LTTPR_REV 0xf0000 +#define DPCD_LTTPR_MODE 0xf0003 +#define DPCD_LTTPR_MODE_TRANSPARENT 0x55 +#define DPCD_LTTPR_MODE_NON_TRANSPARENT 0xaa +#define DPCD_LTTPR_PATTERN_SET(i) ((i - 1) * 0x50 + 0xf0010) +#define DPCD_LTTPR_LANE0_SET(i) ((i - 1) * 0x50 + 0xf0011) +#define DPCD_LTTPR_AUX_RD_INTERVAL(i) ((i - 1) * 0x50 + 0xf0020) +#define DPCD_LTTPR_LANE0_1_STATUS(i) ((i - 1) * 0x50 + 0xf0030) +#define DPCD_LTTPR_LANE0_1_ADJUST(i) ((i - 1) * 0x50 + 0xf0033) #endif