Add the DPCD registers and detection required to support UHBR link rates over Thunderbolt tunnels.
Cc: [email protected] Signed-off-by: Imre Deak <[email protected]> --- drivers/gpu/drm/display/drm_dp_tunnel.c | 116 +++++++++++++++++++++++- include/drm/display/drm_dp.h | 12 +++ include/drm/display/drm_dp_tunnel.h | 21 +++++ 3 files changed, 148 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/display/drm_dp_tunnel.c b/drivers/gpu/drm/display/drm_dp_tunnel.c index 76c6bc84a806f..d29ad4116e641 100644 --- a/drivers/gpu/drm/display/drm_dp_tunnel.c +++ b/drivers/gpu/drm/display/drm_dp_tunnel.c @@ -111,6 +111,8 @@ DPTUN_REG(DP_ALLOCATED_BW) | \ DPTUN_REG(DP_TUNNELING_MAX_LINK_RATE) | \ DPTUN_REG(DP_TUNNELING_MAX_LANE_COUNT) | \ + DPTUN_REG(DP_TUNNELING_MAIN_LINK_CHANNEL_CODING) | \ + DPTUN_REG(DP_TUNNELING_128B132B_LINK_RATE) | \ DPTUN_REG(DP_DPTX_BW_ALLOCATION_MODE_CONTROL)) static const DECLARE_BITMAP(dptun_info_regs, 64) = { @@ -140,11 +142,14 @@ struct drm_dp_tunnel { int estimated_bw; int allocated_bw; + u8 dprx_128b132b_rates; int max_dprx_rate; u8 max_dprx_lane_count; u8 adapter_id; + bool dprx_128b132b_support:1; + bool dprx_128b132b_lane0_mapping_support:1; bool bw_alloc_supported:1; bool bw_alloc_enabled:1; bool has_io_error:1; @@ -260,9 +265,46 @@ static int tunnel_reg_bw_granularity(const struct drm_dp_tunnel_regs *regs) return (250000 << gr) / 8; } +static bool tunnel_reg_dprx_128b132b_support(const struct drm_dp_tunnel_regs *regs) +{ + return tunnel_reg(regs, DP_TUNNELING_MAIN_LINK_CHANNEL_CODING) & DP_128B132B_DP_SUPPORTED; +} + +static bool tunnel_reg_dprx_128b132b_lane0_mapping_support(const struct drm_dp_tunnel_regs *regs) +{ + return tunnel_reg(regs, DP_TUNNELING_128B132B_LINK_RATE) & + DP_TUNNELING_128B132B_LL_LANE0_MAPPING_SUPPORT; +} + +static u8 tunnel_reg_dprx_128b132b_rates(const struct drm_dp_tunnel_regs *regs) +{ + if (!tunnel_reg_dprx_128b132b_support(regs)) + return 0; + + return tunnel_reg(regs, DP_TUNNELING_128B132B_LINK_RATE) & + DP_TUNNELING_128B132B_LINK_RATE_MASK; +} + +static u8 max_128b132b_rate(u8 rates) +{ + if (rates & DP_TUNNELING_20GBPS_PER_LANE_SUPPORT) + return DP_TUNNELING_20GBPS_PER_LANE_SUPPORT; + else if (rates & DP_TUNNELING_13_5GBPS_PER_LANE_SUPPORT) + return DP_TUNNELING_13_5GBPS_PER_LANE_SUPPORT; + else if (rates & DP_TUNNELING_10GBPS_PER_LANE_SUPPORT) + return DP_TUNNELING_10GBPS_PER_LANE_SUPPORT; + + WARN_ON(rates); + + return 0; +} + static int tunnel_reg_max_dprx_rate(const struct drm_dp_tunnel_regs *regs) { - u8 bw_code = tunnel_reg(regs, DP_TUNNELING_MAX_LINK_RATE); + u8 bw_code = max_128b132b_rate(tunnel_reg_dprx_128b132b_rates(regs)); + + if (!bw_code) + bw_code = tunnel_reg(regs, DP_TUNNELING_MAX_LINK_RATE); return drm_dp_bw_code_to_link_rate(bw_code); } @@ -706,6 +748,23 @@ static bool update_dprx_caps(struct drm_dp_tunnel *tunnel, const struct drm_dp_t { bool changed = false; + if (tunnel_reg_dprx_128b132b_support(regs) != tunnel->dprx_128b132b_support) { + tunnel->dprx_128b132b_support = tunnel_reg_dprx_128b132b_support(regs); + changed = true; + } + + if (tunnel_reg_dprx_128b132b_lane0_mapping_support(regs) != + tunnel->dprx_128b132b_lane0_mapping_support) { + tunnel->dprx_128b132b_lane0_mapping_support = + tunnel_reg_dprx_128b132b_lane0_mapping_support(regs); + changed = true; + } + + if (tunnel_reg_dprx_128b132b_rates(regs) != tunnel->dprx_128b132b_rates) { + tunnel->dprx_128b132b_rates = tunnel_reg_dprx_128b132b_rates(regs); + changed = true; + } + if (tunnel_reg_max_dprx_rate(regs) != tunnel->max_dprx_rate) { tunnel->max_dprx_rate = tunnel_reg_max_dprx_rate(regs); changed = true; @@ -1331,6 +1390,61 @@ int drm_dp_tunnel_handle_irq(struct drm_dp_tunnel_mgr *mgr, struct drm_dp_aux *a } EXPORT_SYMBOL(drm_dp_tunnel_handle_irq); +/** + * drm_dp_tunnel_128b132b_supported - Query if 128b132b is supported by the tunnel's DPRX + * @tunnel: Tunnel object + * + * The function is used to query if 128b132b is supported by the DPRX connected + * to @tunnel. + * + * Returns %true if 128b132b is supported by the DPRX. + */ +bool drm_dp_tunnel_128b132b_supported(const struct drm_dp_tunnel *tunnel) +{ + return tunnel->dprx_128b132b_support; +} +EXPORT_SYMBOL(drm_dp_tunnel_128b132b_supported); + +/** + * drm_dp_tunnel_128b132b_lane0_mapping_supported - Check 128b/132b lane 0 mapping support + * @tunnel: Tunnel object + * + * Check whether the DP-out adapter always maps lane 0 as expected by the + * DPRX on a tunneled 128b/132b link. If the function returns %true, one- and + * two-lane configurations with UHBR link rates can always be used. If it + * returns %false, using one or two lanes with UHBR link rates may cause a + * lane-count conversion failure in the DPRX, requiring corrective action by + * the source during link training. See DP Standard v2.1b, section + * 3.5.2.16.3, 128b/132b DPRX Lane Count Conversion Failure Indication and + * Corrective Action. + * + * A four-lane configuration can always be used, provided that the DPRX + * supports it, regardless of the function's return value. + * + * Returns %true if the DP-out adapter supports the 128b/132b lane 0 mapping. + */ +bool drm_dp_tunnel_128b132b_lane0_mapping_supported(const struct drm_dp_tunnel *tunnel) +{ + return tunnel->dprx_128b132b_lane0_mapping_support; +} +EXPORT_SYMBOL(drm_dp_tunnel_128b132b_lane0_mapping_supported); + +/** + * drm_dp_tunnel_128b132b_dprx_rates - Query the supported 128b132b rates of the tunnel's DPRX + * @tunnel: Tunnel object + * + * The function is used to query the supported 128b132b rates of the DPRX connected + * to @tunnel. Note that the related DP_128B132B_SUPPROTED_LINK_RATES DPCD + * register will indicate no supported 128B132B rates for a tunneled DPRX. + * + * Returns the mask of supported 128b132b rates. + */ +u8 drm_dp_tunnel_128b132b_dprx_rates(const struct drm_dp_tunnel *tunnel) +{ + return tunnel->dprx_128b132b_rates; +} +EXPORT_SYMBOL(drm_dp_tunnel_128b132b_dprx_rates); + /** * drm_dp_tunnel_max_dprx_rate - Query the maximum rate of the tunnel's DPRX * @tunnel: Tunnel object diff --git a/include/drm/display/drm_dp.h b/include/drm/display/drm_dp.h index 7154216e0aff9..8b0ca36083dd1 100644 --- a/include/drm/display/drm_dp.h +++ b/include/drm/display/drm_dp.h @@ -1506,6 +1506,18 @@ #define DP_TUNNELING_MAX_LANE_COUNT 0xe0029 #define DP_TUNNELING_MAX_LANE_COUNT_MASK 0x1f +#define DP_TUNNELING_MAIN_LINK_CHANNEL_CODING 0xe002b +#define DP_128B132B_DP_SUPPORTED (1 << 0) + +#define DP_TUNNELING_128B132B_LINK_RATE 0xe002c +#define DP_TUNNELING_13_5GBPS_PER_LANE_SUPPORT (1 << 2) +#define DP_TUNNELING_20GBPS_PER_LANE_SUPPORT (1 << 1) +#define DP_TUNNELING_10GBPS_PER_LANE_SUPPORT (1 << 0) +#define DP_TUNNELING_128B132B_LINK_RATE_MASK (DP_TUNNELING_10GBPS_PER_LANE_SUPPORT | \ + DP_TUNNELING_13_5GBPS_PER_LANE_SUPPORT | \ + DP_TUNNELING_20GBPS_PER_LANE_SUPPORT) +#define DP_TUNNELING_128B132B_LL_LANE0_MAPPING_SUPPORT (1 << 7) + #define DP_DPTX_BW_ALLOCATION_MODE_CONTROL 0xe0030 #define DP_DISPLAY_DRIVER_BW_ALLOCATION_MODE_ENABLE (1 << 7) #define DP_UNMASK_BW_ALLOCATION_IRQ (1 << 6) diff --git a/include/drm/display/drm_dp_tunnel.h b/include/drm/display/drm_dp_tunnel.h index 57f5e90ba8fda..b5e665560a47e 100644 --- a/include/drm/display/drm_dp_tunnel.h +++ b/include/drm/display/drm_dp_tunnel.h @@ -63,6 +63,9 @@ void drm_dp_tunnel_set_io_error(struct drm_dp_tunnel *tunnel); int drm_dp_tunnel_handle_irq(struct drm_dp_tunnel_mgr *mgr, struct drm_dp_aux *aux); +bool drm_dp_tunnel_128b132b_supported(const struct drm_dp_tunnel *tunnel); +bool drm_dp_tunnel_128b132b_lane0_mapping_supported(const struct drm_dp_tunnel *tunnel); +u8 drm_dp_tunnel_128b132b_dprx_rates(const struct drm_dp_tunnel *tunnel); int drm_dp_tunnel_max_dprx_rate(const struct drm_dp_tunnel *tunnel); int drm_dp_tunnel_max_dprx_lane_count(const struct drm_dp_tunnel *tunnel); int drm_dp_tunnel_available_bw(const struct drm_dp_tunnel *tunnel); @@ -173,6 +176,24 @@ drm_dp_tunnel_handle_irq(struct drm_dp_tunnel_mgr *mgr, return -EOPNOTSUPP; } +static inline bool +drm_dp_tunnel_128b132b_supported(const struct drm_dp_tunnel *tunnel) +{ + return false; +} + +static inline bool +drm_dp_tunnel_128b132b_lane0_mapping_supported(const struct drm_dp_tunnel *tunnel) +{ + return false; +} + +static inline u8 +drm_dp_tunnel_128b132b_dprx_rates(const struct drm_dp_tunnel *tunnel) +{ + return 0; +} + static inline int drm_dp_tunnel_max_dprx_rate(const struct drm_dp_tunnel *tunnel) { -- 2.49.1
