drm/hisilicon/hibmc: Add support for VDAC

VDAC(Video Digital-to-Analog converter) converts the RGB diaital data
stream from DE to VGA analog signals.
Signed-off-by: Rongrong Zou <zourongrong@gmail.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Xinliang Liu <xinliang.liu@linaro.org>
Acked-by: Sean Paul <seanpaul@chromium.org>

drivers/gpu/drm/hisilicon/hibmc/Makefile

 ccflags-y := -Iinclude/drm
-hibmc-drm-y := hibmc_drm_drv.o hibmc_drm_de.o hibmc_drm_fbdev.o hibmc_ttm.o
+hibmc-drm-y := hibmc_drm_drv.o hibmc_drm_de.o hibmc_drm_vdac.o hibmc_drm_fbdev.o hibmc_ttm.o
 
 obj-$(CONFIG_DRM_HISI_HIBMC) += hibmc-drm.o

drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c

@@ -123,6 +123,12 @@ static int hibmc_kms_init(struct hibmc_drm_private *priv)
 		return ret;
 	}
 
+	ret = hibmc_vdac_init(priv);
+	if (ret) {
+		DRM_ERROR("failed to init vdac: %d\n", ret);
+		return ret;
+	}
+
 	return 0;
 }
 

drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h

@@ -86,6 +86,7 @@ void hibmc_set_current_gate(struct hibmc_drm_private *priv,
 			    unsigned int gate);
 
 int hibmc_de_init(struct hibmc_drm_private *priv);
+int hibmc_vdac_init(struct hibmc_drm_private *priv);
 int hibmc_fbdev_init(struct hibmc_drm_private *priv);
 void hibmc_fbdev_fini(struct hibmc_drm_private *priv);
 

drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c

+/* Hisilicon Hibmc SoC drm driver
+ *
+ * Based on the bochs drm driver.
+ *
+ * Copyright (c) 2016 Huawei Limited.
+ *
+ * Author:
+ *	Rongrong Zou <zourongrong@huawei.com>
+ *	Rongrong Zou <zourongrong@gmail.com>
+ *	Jianhua Li <lijianhua@huawei.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+
+#include "hibmc_drm_drv.h"
+#include "hibmc_drm_regs.h"
+
+static int hibmc_connector_get_modes(struct drm_connector *connector)
+{
+	return drm_add_modes_noedid(connector, 800, 600);
+}
+
+static int hibmc_connector_mode_valid(struct drm_connector *connector,
+				      struct drm_display_mode *mode)
+{
+	return MODE_OK;
+}
+
+static struct drm_encoder *
+hibmc_connector_best_encoder(struct drm_connector *connector)
+{
+	return drm_encoder_find(connector->dev, connector->encoder_ids[0]);
+}
+
+static enum drm_connector_status hibmc_connector_detect(struct drm_connector
+						 *connector, bool force)
+{
+	return connector_status_connected;
+}
+
+static const struct drm_connector_helper_funcs
+	hibmc_connector_helper_funcs = {
+	.get_modes = hibmc_connector_get_modes,
+	.mode_valid = hibmc_connector_mode_valid,
+	.best_encoder = hibmc_connector_best_encoder,
+};
+
+static const struct drm_connector_funcs hibmc_connector_funcs = {
+	.dpms = drm_atomic_helper_connector_dpms,
+	.detect = hibmc_connector_detect,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = drm_connector_cleanup,
+	.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 struct drm_connector *
+hibmc_connector_init(struct hibmc_drm_private *priv)
+{
+	struct drm_device *dev = priv->dev;
+	struct drm_connector *connector;
+	int ret;
+
+	connector = devm_kzalloc(dev->dev, sizeof(*connector), GFP_KERNEL);
+	if (!connector) {
+		DRM_ERROR("failed to alloc memory when init connector\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ret = drm_connector_init(dev, connector,
+				 &hibmc_connector_funcs,
+				 DRM_MODE_CONNECTOR_VGA);
+	if (ret) {
+		DRM_ERROR("failed to init connector: %d\n", ret);
+		return ERR_PTR(ret);
+	}
+	drm_connector_helper_add(connector,
+				 &hibmc_connector_helper_funcs);
+
+	return connector;
+}
+
+static void hibmc_encoder_mode_set(struct drm_encoder *encoder,
+				   struct drm_display_mode *mode,
+				   struct drm_display_mode *adj_mode)
+{
+	u32 reg;
+	struct drm_device *dev = encoder->dev;
+	struct hibmc_drm_private *priv = dev->dev_private;
+
+	reg = readl(priv->mmio + HIBMC_DISPLAY_CONTROL_HISILE);
+	reg |= HIBMC_DISPLAY_CONTROL_FPVDDEN(1);
+	reg |= HIBMC_DISPLAY_CONTROL_PANELDATE(1);
+	reg |= HIBMC_DISPLAY_CONTROL_FPEN(1);
+	reg |= HIBMC_DISPLAY_CONTROL_VBIASEN(1);
+	writel(reg, priv->mmio + HIBMC_DISPLAY_CONTROL_HISILE);
+}
+
+static const struct drm_encoder_helper_funcs hibmc_encoder_helper_funcs = {
+	.mode_set = hibmc_encoder_mode_set,
+};
+
+static const struct drm_encoder_funcs hibmc_encoder_funcs = {
+	.destroy = drm_encoder_cleanup,
+};
+
+int hibmc_vdac_init(struct hibmc_drm_private *priv)
+{
+	struct drm_device *dev = priv->dev;
+	struct drm_encoder *encoder;
+	struct drm_connector *connector;
+	int ret;
+
+	connector = hibmc_connector_init(priv);
+	if (IS_ERR(connector)) {
+		DRM_ERROR("failed to create connector: %ld\n",
+			  PTR_ERR(connector));
+		return PTR_ERR(connector);
+	}
+
+	encoder = devm_kzalloc(dev->dev, sizeof(*encoder), GFP_KERNEL);
+	if (!encoder) {
+		DRM_ERROR("failed to alloc memory when init encoder\n");
+		return -ENOMEM;
+	}
+
+	encoder->possible_crtcs = 0x1;
+	ret = drm_encoder_init(dev, encoder, &hibmc_encoder_funcs,
+			       DRM_MODE_ENCODER_DAC, NULL);
+	if (ret) {
+		DRM_ERROR("failed to init encoder: %d\n", ret);
+		return ret;
+	}
+
+	drm_encoder_helper_add(encoder, &hibmc_encoder_helper_funcs);
+	drm_mode_connector_attach_encoder(connector, encoder);
+
+	return 0;
+}