[Intel-gfx] [RFC-v2 5/9] drm/i915/dsi: Add check for periodic command mode

[Vandita Kulkarni]

If the GOP has programmed periodic command mode,
we need to disable that which would need a
deconfigure and configure sequence.

Signed-off-by: Vandita Kulkarni <vandita.kulkarni at intel.com>
---
 drivers/gpu/drm/i915/display/icl_dsi.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c b/drivers/gpu/drm/i915/display/icl_dsi.c
index 488620365f76..7aadc4e9ac6f 100644
--- a/drivers/gpu/drm/i915/display/icl_dsi.c
+++ b/drivers/gpu/drm/i915/display/icl_dsi.c
@@ -1287,6 +1287,21 @@ static void gen11_dsi_get_timings(struct intel_encoder *encoder,
 	adjusted_mode->crtc_vblank_end = adjusted_mode->crtc_vtotal;
 }
 
+bool gen11_dsi_is_periodic_cmd_mode(struct drm_i915_private *dev_priv,
+				    struct intel_dsi *intel_dsi)
+{
+	u32 val;
+	enum transcoder dsi_trans;
+
+	if (intel_dsi->ports == BIT(PORT_B))
+		dsi_trans = TRANSCODER_DSI_1;
+	else
+		dsi_trans = TRANSCODER_DSI_0;
+
+	val = I915_READ(DSI_TRANS_FUNC_CONF(dsi_trans));
+	return (val & DSI_PERIODIC_FRAME_UPDATE_ENABLE);
+}
+
 static void gen11_dsi_get_config(struct intel_encoder *encoder,
 				 struct intel_crtc_state *pipe_config)
 {
@@ -1305,6 +1320,10 @@ static void gen11_dsi_get_config(struct intel_encoder *encoder,
 	gen11_dsi_get_timings(encoder, pipe_config);
 	pipe_config->output_types |= BIT(INTEL_OUTPUT_DSI);
 	pipe_config->pipe_bpp = bdw_get_pipemisc_bpp(crtc);
+
+	if (gen11_dsi_is_periodic_cmd_mode(dev_priv, intel_dsi))
+		pipe_config->hw.adjusted_mode.private_flags |=
+					I915_MODE_FLAG_DSI_PERIODIC_CMD_MODE;
 }
 
 static int gen11_dsi_compute_config(struct intel_encoder *encoder,
@@ -1335,6 +1354,9 @@ static int gen11_dsi_compute_config(struct intel_encoder *encoder,
 	pipe_config->clock_set = true;
 	pipe_config->port_clock = intel_dsi_bitrate(intel_dsi) / 5;
 
+	/* We would not opereate in peridoc command mode */
+	pipe_config->hw.adjusted_mode.private_flags &=
+					~I915_MODE_FLAG_DSI_PERIODIC_CMD_MODE;
 	return 0;
 }
 
-- 
2.21.0.5.gaeb582a