[PATCH v2 2/7] drm/tegra: rgb: Parameterize configuration based on bus flags

[Svyatoslav Ryhel <clamor95@gmail.com>]

Parameterize configuration based on bus flags passed from the bridge or
panel. The list of supported flags includes now pixel clock polarity,
display enable (DE) polarity, and data alignment.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 drivers/gpu/drm/tegra/rgb.c | 41 ++++++++++++++++++++++++++++++++-----
 1 file changed, 36 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c
index bc1c93c7554c5..8167447cec900 100644
--- a/drivers/gpu/drm/tegra/rgb.c
+++ b/drivers/gpu/drm/tegra/rgb.c
@@ -5,6 +5,7 @@
  */
 
 #include <linux/clk.h>
+#include <linux/media-bus-format.h>
 #include <linux/of.h>
 
 #include <drm/drm_atomic_helper.h>
@@ -103,14 +104,24 @@ static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
 	struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
 	struct tegra_output *output = encoder_to_output(encoder);
 	struct tegra_rgb *rgb = to_rgb(output);
-	u32 value;
+	struct drm_bridge_state *bridge_state;
+	u32 bus_flags, value;
+
+	/* Get but flags from the bridge state. */
+	bridge_state = drm_bridge_get_current_state(output->bridge);
+	if (bridge_state)
+		bus_flags = bridge_state->input_bus_cfg.flags;
+	else
+		bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE |
+			    DRM_BUS_FLAG_DE_HIGH |
+			    DRM_BUS_FLAG_DATA_MSB_TO_LSB;
 
 	tegra_dc_write_regs(rgb->dc, rgb_enable, ARRAY_SIZE(rgb_enable));
 
 	value = DE_SELECT_ACTIVE | DE_CONTROL_NORMAL;
 	tegra_dc_writel(rgb->dc, value, DC_DISP_DATA_ENABLE_OPTIONS);
 
-	/* configure H- and V-sync signal polarities */
+	/* configure H- and V-sync and pixel clock signal polarities */
 	value = tegra_dc_readl(rgb->dc, DC_COM_PIN_OUTPUT_POLARITY(1));
 
 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
@@ -123,11 +134,31 @@ static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
 	else
 		value &= ~LVS_OUTPUT_POLARITY_LOW;
 
+	if (bus_flags & DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE)
+		value &= ~LSC0_OUTPUT_POLARITY_LOW;
+	else
+		value |= LSC0_OUTPUT_POLARITY_LOW;
+
 	tegra_dc_writel(rgb->dc, value, DC_COM_PIN_OUTPUT_POLARITY(1));
 
-	/* XXX: parameterize? */
-	value = DISP_DATA_FORMAT_DF1P1C | DISP_ALIGNMENT_MSB |
-		DISP_ORDER_RED_BLUE;
+	/* configure DE signal polarities */
+	value = tegra_dc_readl(rgb->dc, DC_COM_PIN_OUTPUT_POLARITY(3));
+
+	if (bus_flags & DRM_BUS_FLAG_DE_LOW)
+		value |= LSPI_OUTPUT_POLARITY_LOW;
+	else
+		value &= ~LSPI_OUTPUT_POLARITY_LOW;
+
+	tegra_dc_writel(rgb->dc, value, DC_COM_PIN_OUTPUT_POLARITY(3));
+
+	/* configure DATA order and alignment */
+	value = DISP_DATA_FORMAT_DF1P1C | DISP_ORDER_RED_BLUE;
+
+	if (bus_flags & DRM_BUS_FLAG_DATA_LSB_TO_MSB)
+		value |= DISP_ALIGNMENT_LSB;
+	else
+		value &= ~DISP_ALIGNMENT_LSB;
+
 	tegra_dc_writel(rgb->dc, value, DC_DISP_DISP_INTERFACE_CONTROL);
 
 	tegra_dc_commit(rgb->dc);
-- 
2.53.0