drm/i915/icl: Disable DSI transcoders

This patch disables transcoders by writing to TRANS_CONF
registers for each DSI ports.

v2 by Jani:
 - Wait for pipeconf active to go low

Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/c76035309fa721322cf9c1ca7fc42b822937c2f3.1540900289.git.jani.nikula@intel.com

diff --git a/drivers/gpu/drm/i915/icl_dsi.c b/drivers/gpu/drm/i915/icl_dsi.c
index f7f48ff..644ad74 100644 (file)
--- a/drivers/gpu/drm/i915/icl_dsi.c
+++ b/drivers/gpu/drm/i915/icl_dsi.c
@@ -777,6 +777,29 @@ gen11_dsi_pre_enable(struct intel_encoder *encoder,
        intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_ON);
 }
 
+static void gen11_dsi_disable_transcoder(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;
+       enum transcoder dsi_trans;
+       u32 tmp;
+
+       for_each_dsi_port(port, intel_dsi->ports) {
+               dsi_trans = dsi_port_to_transcoder(port);
+
+               /* disable transcoder */
+               tmp = I915_READ(PIPECONF(dsi_trans));
+               tmp &= ~PIPECONF_ENABLE;
+               I915_WRITE(PIPECONF(dsi_trans), tmp);
+
+               /* wait for transcoder to be disabled */
+               if (intel_wait_for_register(dev_priv, PIPECONF(dsi_trans),
+                                           I965_PIPECONF_ACTIVE, 0, 50))
+                       DRM_ERROR("DSI trancoder not disabled\n");
+       }
+}
+
 static void __attribute__((unused)) gen11_dsi_disable(
                        struct intel_encoder *encoder,
                        const struct intel_crtc_state *old_crtc_state,
@@ -787,4 +810,7 @@ static void __attribute__((unused)) gen11_dsi_disable(
        /* step1: turn off backlight */
        intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_OFF);
        intel_panel_disable_backlight(old_conn_state);
+
+       /* step2d,e: disable transcoder and wait */
+       gen11_dsi_disable_transcoder(encoder);
 }