> Subject: [PATCH 1/6] drm/dp_tunnel: Add UHBR tunneling support > > 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]>
LGTM, Reviewed-by: Suraj Kandpal <[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
