drm/i915/dsi: add support for DSC

Enable DSC for DSI, if specified in VBT.

This still lacks DSC aware get config implementation, and therefore
state checker will fail. Also mode valid is not there yet.

v5:
- add dsc get config call

v4:
- convert_rgb = true (Vandita)
- ignore max cdclock check (Vandita)
- rename pipe_config to crtc_state

v3:
- take compressed bpp into account

v2:
- Nuke conn_state->max_requested_bpc, it's not used on DSI

Bspec: 49263
Cc: Vandita Kulkarni <vandita.kulkarni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e0136299e03c582238523189f6951eeb08daed98.1575974743.git.jani.nikula@intel.com

drivers/gpu/drm/i915/display/icl_dsi.c

@@ -34,6 +34,7 @@
 #include "intel_ddi.h"
 #include "intel_dsi.h"
 #include "intel_panel.h"
+#include "intel_vdsc.h"
 
 static inline int header_credits_available(struct drm_i915_private *dev_priv,
 					   enum transcoder dsi_trans)
@@ -1087,6 +1088,8 @@ static void gen11_dsi_pre_enable(struct intel_encoder *encoder,
 	/* step5: program and powerup panel */
 	gen11_dsi_powerup_panel(encoder);
 
+	intel_dsc_enable(encoder, pipe_config);
+
 	/* step6c: configure transcoder timings */
 	gen11_dsi_set_transcoder_timings(encoder, pipe_config);
 
@@ -1248,6 +1251,13 @@ static void gen11_dsi_disable(struct intel_encoder *encoder,
 	gen11_dsi_disable_io_power(encoder);
 }
 
+static enum drm_mode_status gen11_dsi_mode_valid(struct drm_connector *connector,
+						 struct drm_display_mode *mode)
+{
+	/* FIXME: DSC? */
+	return intel_dsi_mode_valid(connector, mode);
+}
+
 static void gen11_dsi_get_timings(struct intel_encoder *encoder,
 				  struct intel_crtc_state *pipe_config)
 {
@@ -1294,6 +1304,8 @@ static void gen11_dsi_get_config(struct intel_encoder *encoder,
 	struct intel_crtc *crtc = to_intel_crtc(pipe_config->uapi.crtc);
 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
 
+	intel_dsc_get_config(encoder, pipe_config);
+
 	/* FIXME: adapt icl_ddi_clock_get() for DSI and use that? */
 	pipe_config->port_clock =
 		cnl_calc_wrpll_link(dev_priv, &pipe_config->dpll_hw_state);
@@ -1307,6 +1319,48 @@ static void gen11_dsi_get_config(struct intel_encoder *encoder,
 	pipe_config->pipe_bpp = bdw_get_pipemisc_bpp(crtc);
 }
 
+static int gen11_dsi_dsc_compute_config(struct intel_encoder *encoder,
+					struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	struct drm_dsc_config *vdsc_cfg = &crtc_state->dsc.config;
+	int dsc_max_bpc = INTEL_GEN(dev_priv) >= 12 ? 12 : 10;
+	bool use_dsc;
+	int ret;
+
+	use_dsc = intel_bios_get_dsc_params(encoder, crtc_state, dsc_max_bpc);
+	if (!use_dsc)
+		return 0;
+
+	if (crtc_state->pipe_bpp < 8 * 3)
+		return -EINVAL;
+
+	/* FIXME: split only when necessary */
+	if (crtc_state->dsc.slice_count > 1)
+		crtc_state->dsc.dsc_split = true;
+
+	vdsc_cfg->convert_rgb = true;
+
+	ret = intel_dsc_compute_params(encoder, crtc_state);
+	if (ret)
+		return ret;
+
+	/* DSI specific sanity checks on the common code */
+	WARN_ON(vdsc_cfg->vbr_enable);
+	WARN_ON(vdsc_cfg->simple_422);
+	WARN_ON(vdsc_cfg->pic_width % vdsc_cfg->slice_width);
+	WARN_ON(vdsc_cfg->slice_height < 8);
+	WARN_ON(vdsc_cfg->pic_height % vdsc_cfg->slice_height);
+
+	ret = drm_dsc_compute_rc_parameters(vdsc_cfg);
+	if (ret)
+		return ret;
+
+	crtc_state->dsc.compression_enable = true;
+
+	return 0;
+}
+
 static int gen11_dsi_compute_config(struct intel_encoder *encoder,
 				    struct intel_crtc_state *pipe_config,
 				    struct drm_connector_state *conn_state)
@@ -1338,6 +1392,10 @@ static int gen11_dsi_compute_config(struct intel_encoder *encoder,
 		pipe_config->pipe_bpp = 18;
 
 	pipe_config->clock_set = true;
+
+	if (gen11_dsi_dsc_compute_config(encoder, pipe_config))
+		DRM_DEBUG_KMS("Attempting to use DSC failed\n");
+
 	pipe_config->port_clock = afe_clk(encoder, pipe_config) / 5;
 
 	return 0;
@@ -1346,8 +1404,13 @@ static int gen11_dsi_compute_config(struct intel_encoder *encoder,
 static void gen11_dsi_get_power_domains(struct intel_encoder *encoder,
 					struct intel_crtc_state *crtc_state)
 {
-	get_dsi_io_power_domains(to_i915(encoder->base.dev),
-				 enc_to_intel_dsi(&encoder->base));
+	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
+
+	get_dsi_io_power_domains(i915, enc_to_intel_dsi(&encoder->base));
+
+	if (crtc_state->dsc.compression_enable)
+		intel_display_power_get(i915,
+					intel_dsc_power_domain(crtc_state));
 }
 
 static bool gen11_dsi_get_hw_state(struct intel_encoder *encoder,
@@ -1417,7 +1480,7 @@ static const struct drm_connector_funcs gen11_dsi_connector_funcs = {
 
 static const struct drm_connector_helper_funcs gen11_dsi_connector_helper_funcs = {
 	.get_modes = intel_dsi_get_modes,
-	.mode_valid = intel_dsi_mode_valid,
+	.mode_valid = gen11_dsi_mode_valid,
 	.atomic_check = intel_digital_connector_atomic_check,
 };