From: Madhav Chauhan Date: Thu, 5 Jul 2018 19:19:37 +0530 Subject: drm/i915/icl: Power down unused DSI lanes Git-commit: 45f09f7adc8a10138b158c5805a4d3b20aac611a Patch-mainline: v4.19-rc1 References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166 To save power, unused lanes should be powered down using the bitfield of PORT_CL_DW10. v2: Review comments from Jani N - Put default label next to case 4 - Include the shifts in the macros Signed-off-by: Madhav Chauhan Reviewed-by: Jani Nikula Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/1530798591-2077-7-git-send-email-madhav.chauhan@intel.com Acked-by: Petr Tesarik --- drivers/gpu/drm/i915/icl_dsi.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) --- a/drivers/gpu/drm/i915/icl_dsi.c +++ b/drivers/gpu/drm/i915/icl_dsi.c @@ -74,6 +74,43 @@ static void gen11_dsi_enable_io_power(st } } +static void gen11_dsi_power_up_lanes(struct intel_encoder *encoder) +{ + struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); + struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base); + enum port port; + u32 tmp; + u32 lane_mask; + + switch (intel_dsi->lane_count) { + case 1: + lane_mask = PWR_DOWN_LN_3_1_0; + break; + case 2: + lane_mask = PWR_DOWN_LN_3_1; + break; + case 3: + lane_mask = PWR_DOWN_LN_3; + break; + case 4: + default: + lane_mask = PWR_UP_ALL_LANES; + break; + } + + for_each_dsi_port(port, intel_dsi->ports) { + tmp = I915_READ(ICL_PORT_CL_DW10(port)); + tmp &= ~PWR_DOWN_LN_MASK; + I915_WRITE(ICL_PORT_CL_DW10(port), tmp | lane_mask); + } +} + +static void gen11_dsi_enable_port_and_phy(struct intel_encoder *encoder) +{ + /* step 4a: power up all lanes of the DDI used by DSI */ + gen11_dsi_power_up_lanes(encoder); +} + static void __attribute__((unused)) gen11_dsi_pre_enable(struct intel_encoder *encoder, const struct intel_crtc_state *pipe_config, @@ -84,4 +121,7 @@ gen11_dsi_pre_enable(struct intel_encode /* step3: enable DSI PLL */ gen11_dsi_program_esc_clk_div(encoder); + + /* step4: enable DSI port and DPHY */ + gen11_dsi_enable_port_and_phy(encoder); }