1 files changed, 248 insertions, 0 deletions
diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
new file mode 100644
index 000000000..dfb6acc42
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2015 Free Electrons
+ * Copyright (C) 2015 NextThing Co
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+
+#include <linux/clk.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_simple_kms_helper.h>
+
+#include "sun4i_crtc.h"
+#include "sun4i_tcon.h"
+#include "sun4i_rgb.h"
+
+struct sun4i_rgb {
+	struct drm_connector	connector;
+	struct drm_encoder	encoder;
+
+	struct sun4i_tcon	*tcon;
+	struct drm_panel	*panel;
+	struct drm_bridge	*bridge;
+};
+
+static inline struct sun4i_rgb *
+drm_connector_to_sun4i_rgb(struct drm_connector *connector)
+{
+	return container_of(connector, struct sun4i_rgb,
+			    connector);
+}
+
+static inline struct sun4i_rgb *
+drm_encoder_to_sun4i_rgb(struct drm_encoder *encoder)
+{
+	return container_of(encoder, struct sun4i_rgb,
+			    encoder);
+}
+
+static int sun4i_rgb_get_modes(struct drm_connector *connector)
+{
+	struct sun4i_rgb *rgb =
+		drm_connector_to_sun4i_rgb(connector);
+
+	return drm_panel_get_modes(rgb->panel, connector);
+}
+
+/*
+ * VESA DMT defines a tolerance of 0.5% on the pixel clock, while the
+ * CVT spec reuses that tolerance in its examples, so it looks to be a
+ * good default tolerance for the EDID-based modes. Define it to 5 per
+ * mille to avoid floating point operations.
+ */
+#define SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE	5
+
+static enum drm_mode_status sun4i_rgb_mode_valid(struct drm_encoder *crtc,
+						 const struct drm_display_mode *mode)
+{
+	struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(crtc);
+	struct sun4i_tcon *tcon = rgb->tcon;
+	u32 hsync = mode->hsync_end - mode->hsync_start;
+	u32 vsync = mode->vsync_end - mode->vsync_start;
+	unsigned long long rate = mode->clock * 1000;
+	unsigned long long lowest, highest;
+	unsigned long long rounded_rate;
+
+	DRM_DEBUG_DRIVER("Validating modes...\n");
+
+	if (hsync < 1)
+		return MODE_HSYNC_NARROW;
+
+	if (hsync > 0x3ff)
+		return MODE_HSYNC_WIDE;
+
+	if ((mode->hdisplay < 1) || (mode->htotal < 1))
+		return MODE_H_ILLEGAL;
+
+	if ((mode->hdisplay > 0x7ff) || (mode->htotal > 0xfff))
+		return MODE_BAD_HVALUE;
+
+	DRM_DEBUG_DRIVER("Horizontal parameters OK\n");
+
+	if (vsync < 1)
+		return MODE_VSYNC_NARROW;
+
+	if (vsync > 0x3ff)
+		return MODE_VSYNC_WIDE;
+
+	if ((mode->vdisplay < 1) || (mode->vtotal < 1))
+		return MODE_V_ILLEGAL;
+
+	if ((mode->vdisplay > 0x7ff) || (mode->vtotal > 0xfff))
+		return MODE_BAD_VVALUE;
+
+	DRM_DEBUG_DRIVER("Vertical parameters OK\n");
+
+	/*
+	 * TODO: We should use the struct display_timing if available
+	 * and / or trying to stretch the timings within that
+	 * tolerancy to take care of panels that we wouldn't be able
+	 * to have a exact match for.
+	 */
+	if (rgb->panel) {
+		DRM_DEBUG_DRIVER("RGB panel used, skipping clock rate checks");
+		goto out;
+	}
+
+	/*
+	 * That shouldn't ever happen unless something is really wrong, but it
+	 * doesn't harm to check.
+	 */
+	if (!rgb->bridge)
+		goto out;
+
+	tcon->dclk_min_div = 6;
+	tcon->dclk_max_div = 127;
+	rounded_rate = clk_round_rate(tcon->dclk, rate);
+
+	lowest = rate * (1000 - SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
+	do_div(lowest, 1000);
+	if (rounded_rate < lowest)
+		return MODE_CLOCK_LOW;
+
+	highest = rate * (1000 + SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
+	do_div(highest, 1000);
+	if (rounded_rate > highest)
+		return MODE_CLOCK_HIGH;
+
+out:
+	DRM_DEBUG_DRIVER("Clock rate OK\n");
+
+	return MODE_OK;
+}
+
+static const struct drm_connector_helper_funcs sun4i_rgb_con_helper_funcs = {
+	.get_modes	= sun4i_rgb_get_modes,
+};
+
+static void
+sun4i_rgb_connector_destroy(struct drm_connector *connector)
+{
+	drm_connector_cleanup(connector);
+}
+
+static const struct drm_connector_funcs sun4i_rgb_con_funcs = {
+	.fill_modes		= drm_helper_probe_single_connector_modes,
+	.destroy		= sun4i_rgb_connector_destroy,
+	.reset			= drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
+};
+
+static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
+{
+	struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
+
+	DRM_DEBUG_DRIVER("Enabling RGB output\n");
+
+	if (rgb->panel) {
+		drm_panel_prepare(rgb->panel);
+		drm_panel_enable(rgb->panel);
+	}
+}
+
+static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
+{
+	struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
+
+	DRM_DEBUG_DRIVER("Disabling RGB output\n");
+
+	if (rgb->panel) {
+		drm_panel_disable(rgb->panel);
+		drm_panel_unprepare(rgb->panel);
+	}
+}
+
+static const struct drm_encoder_helper_funcs sun4i_rgb_enc_helper_funcs = {
+	.disable	= sun4i_rgb_encoder_disable,
+	.enable		= sun4i_rgb_encoder_enable,
+	.mode_valid	= sun4i_rgb_mode_valid,
+};
+
+int sun4i_rgb_init(struct drm_device *drm, struct sun4i_tcon *tcon)
+{
+	struct drm_encoder *encoder;
+	struct sun4i_rgb *rgb;
+	int ret;
+
+	rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
+	if (!rgb)
+		return -ENOMEM;
+	rgb->tcon = tcon;
+	encoder = &rgb->encoder;
+
+	ret = drm_of_find_panel_or_bridge(tcon->dev->of_node, 1, 0,
+					  &rgb->panel, &rgb->bridge);
+	if (ret) {
+		dev_info(drm->dev, "No panel or bridge found... RGB output disabled\n");
+		return 0;
+	}
+
+	drm_encoder_helper_add(&rgb->encoder,
+			       &sun4i_rgb_enc_helper_funcs);
+	ret = drm_simple_encoder_init(drm, &rgb->encoder,
+				      DRM_MODE_ENCODER_NONE);
+	if (ret) {
+		dev_err(drm->dev, "Couldn't initialise the rgb encoder\n");
+		goto err_out;
+	}
+
+	/* The RGB encoder can only work with the TCON channel 0 */
+	rgb->encoder.possible_crtcs = drm_crtc_mask(&tcon->crtc->crtc);
+
+	if (rgb->panel) {
+		drm_connector_helper_add(&rgb->connector,
+					 &sun4i_rgb_con_helper_funcs);
+		ret = drm_connector_init(drm, &rgb->connector,
+					 &sun4i_rgb_con_funcs,
+					 DRM_MODE_CONNECTOR_Unknown);
+		if (ret) {
+			dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
+			goto err_cleanup_connector;
+		}
+
+		drm_connector_attach_encoder(&rgb->connector,
+						  &rgb->encoder);
+	}
+
+	if (rgb->bridge) {
+		ret = drm_bridge_attach(encoder, rgb->bridge, NULL, 0);
+		if (ret)
+			goto err_cleanup_connector;
+	}
+
+	return 0;
+
+err_cleanup_connector:
+	drm_encoder_cleanup(&rgb->encoder);
+err_out:
+	return ret;
+}
+EXPORT_SYMBOL(sun4i_rgb_init);