8 files changed, 683 insertions, 0 deletions

diff --git a/drivers/gpu/drm/arc/Kconfig b/drivers/gpu/drm/arc/Kconfig
new file mode 100644
index 000000000..e8f3d63e0
--- /dev/null
+++ b/drivers/gpu/drm/arc/Kconfig
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config DRM_ARCPGU
+	tristate "ARC PGU"
+	depends on DRM && OF
+	select DRM_KMS_CMA_HELPER
+	select DRM_KMS_HELPER
+	help
+	  Choose this option if you have an ARC PGU controller.
+
+	  If M is selected the module will be called arcpgu.
diff --git a/drivers/gpu/drm/arc/Makefile b/drivers/gpu/drm/arc/Makefile
new file mode 100644
index 000000000..c7028b742
--- /dev/null
+++ b/drivers/gpu/drm/arc/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+arcpgu-y := arcpgu_crtc.o arcpgu_hdmi.o arcpgu_sim.o arcpgu_drv.o
+obj-$(CONFIG_DRM_ARCPGU) += arcpgu.o
diff --git a/drivers/gpu/drm/arc/arcpgu.h b/drivers/gpu/drm/arc/arcpgu.h
new file mode 100644
index 000000000..6aac44b95
--- /dev/null
+++ b/drivers/gpu/drm/arc/arcpgu.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * ARC PGU DRM driver.
+ *
+ * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#ifndef _ARCPGU_H_
+#define _ARCPGU_H_
+
+struct arcpgu_drm_private {
+	void __iomem		*regs;
+	struct clk		*clk;
+	struct drm_framebuffer	*fb;
+	struct drm_crtc		crtc;
+	struct drm_plane	*plane;
+};
+
+#define crtc_to_arcpgu_priv(x) container_of(x, struct arcpgu_drm_private, crtc)
+
+static inline void arc_pgu_write(struct arcpgu_drm_private *arcpgu,
+				 unsigned int reg, u32 value)
+{
+	iowrite32(value, arcpgu->regs + reg);
+}
+
+static inline u32 arc_pgu_read(struct arcpgu_drm_private *arcpgu,
+			       unsigned int reg)
+{
+	return ioread32(arcpgu->regs + reg);
+}
+
+int arc_pgu_setup_crtc(struct drm_device *dev);
+int arcpgu_drm_hdmi_init(struct drm_device *drm, struct device_node *np);
+int arcpgu_drm_sim_init(struct drm_device *drm, struct device_node *np);
+
+#endif
diff --git a/drivers/gpu/drm/arc/arcpgu_crtc.c b/drivers/gpu/drm/arc/arcpgu_crtc.c
new file mode 100644
index 000000000..be7c29cec
--- /dev/null
+++ b/drivers/gpu/drm/arc/arcpgu_crtc.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ARC PGU DRM driver.
+ *
+ * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_device.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_plane_helper.h>
+#include <drm/drm_probe_helper.h>
+#include <linux/clk.h>
+#include <linux/platform_data/simplefb.h>
+
+#include "arcpgu.h"
+#include "arcpgu_regs.h"
+
+#define ENCODE_PGU_XY(x, y)	((((x) - 1) << 16) | ((y) - 1))
+
+static const u32 arc_pgu_supported_formats[] = {
+	DRM_FORMAT_RGB565,
+	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_ARGB8888,
+};
+
+static void arc_pgu_set_pxl_fmt(struct drm_crtc *crtc)
+{
+	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
+	const struct drm_framebuffer *fb = crtc->primary->state->fb;
+	uint32_t pixel_format = fb->format->format;
+	u32 format = DRM_FORMAT_INVALID;
+	int i;
+	u32 reg_ctrl;
+
+	for (i = 0; i < ARRAY_SIZE(arc_pgu_supported_formats); i++) {
+		if (arc_pgu_supported_formats[i] == pixel_format)
+			format = arc_pgu_supported_formats[i];
+	}
+
+	if (WARN_ON(format == DRM_FORMAT_INVALID))
+		return;
+
+	reg_ctrl = arc_pgu_read(arcpgu, ARCPGU_REG_CTRL);
+	if (format == DRM_FORMAT_RGB565)
+		reg_ctrl &= ~ARCPGU_MODE_XRGB8888;
+	else
+		reg_ctrl |= ARCPGU_MODE_XRGB8888;
+	arc_pgu_write(arcpgu, ARCPGU_REG_CTRL, reg_ctrl);
+}
+
+static const struct drm_crtc_funcs arc_pgu_crtc_funcs = {
+	.destroy = drm_crtc_cleanup,
+	.set_config = drm_atomic_helper_set_config,
+	.page_flip = drm_atomic_helper_page_flip,
+	.reset = drm_atomic_helper_crtc_reset,
+	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+};
+
+static enum drm_mode_status arc_pgu_crtc_mode_valid(struct drm_crtc *crtc,
+						    const struct drm_display_mode *mode)
+{
+	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
+	long rate, clk_rate = mode->clock * 1000;
+	long diff = clk_rate / 200; /* +-0.5% allowed by HDMI spec */
+
+	rate = clk_round_rate(arcpgu->clk, clk_rate);
+	if ((max(rate, clk_rate) - min(rate, clk_rate) < diff) && (rate > 0))
+		return MODE_OK;
+
+	return MODE_NOCLOCK;
+}
+
+static void arc_pgu_crtc_mode_set_nofb(struct drm_crtc *crtc)
+{
+	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
+	struct drm_display_mode *m = &crtc->state->adjusted_mode;
+	u32 val;
+
+	arc_pgu_write(arcpgu, ARCPGU_REG_FMT,
+		      ENCODE_PGU_XY(m->crtc_htotal, m->crtc_vtotal));
+
+	arc_pgu_write(arcpgu, ARCPGU_REG_HSYNC,
+		      ENCODE_PGU_XY(m->crtc_hsync_start - m->crtc_hdisplay,
+				    m->crtc_hsync_end - m->crtc_hdisplay));
+
+	arc_pgu_write(arcpgu, ARCPGU_REG_VSYNC,
+		      ENCODE_PGU_XY(m->crtc_vsync_start - m->crtc_vdisplay,
+				    m->crtc_vsync_end - m->crtc_vdisplay));
+
+	arc_pgu_write(arcpgu, ARCPGU_REG_ACTIVE,
+		      ENCODE_PGU_XY(m->crtc_hblank_end - m->crtc_hblank_start,
+				    m->crtc_vblank_end - m->crtc_vblank_start));
+
+	val = arc_pgu_read(arcpgu, ARCPGU_REG_CTRL);
+
+	if (m->flags & DRM_MODE_FLAG_PVSYNC)
+		val |= ARCPGU_CTRL_VS_POL_MASK << ARCPGU_CTRL_VS_POL_OFST;
+	else
+		val &= ~(ARCPGU_CTRL_VS_POL_MASK << ARCPGU_CTRL_VS_POL_OFST);
+
+	if (m->flags & DRM_MODE_FLAG_PHSYNC)
+		val |= ARCPGU_CTRL_HS_POL_MASK << ARCPGU_CTRL_HS_POL_OFST;
+	else
+		val &= ~(ARCPGU_CTRL_HS_POL_MASK << ARCPGU_CTRL_HS_POL_OFST);
+
+	arc_pgu_write(arcpgu, ARCPGU_REG_CTRL, val);
+	arc_pgu_write(arcpgu, ARCPGU_REG_STRIDE, 0);
+	arc_pgu_write(arcpgu, ARCPGU_REG_START_SET, 1);
+
+	arc_pgu_set_pxl_fmt(crtc);
+
+	clk_set_rate(arcpgu->clk, m->crtc_clock * 1000);
+}
+
+static void arc_pgu_crtc_atomic_enable(struct drm_crtc *crtc,
+				       struct drm_crtc_state *old_state)
+{
+	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
+
+	clk_prepare_enable(arcpgu->clk);
+	arc_pgu_write(arcpgu, ARCPGU_REG_CTRL,
+		      arc_pgu_read(arcpgu, ARCPGU_REG_CTRL) |
+		      ARCPGU_CTRL_ENABLE_MASK);
+}
+
+static void arc_pgu_crtc_atomic_disable(struct drm_crtc *crtc,
+					struct drm_crtc_state *old_state)
+{
+	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
+
+	clk_disable_unprepare(arcpgu->clk);
+	arc_pgu_write(arcpgu, ARCPGU_REG_CTRL,
+			      arc_pgu_read(arcpgu, ARCPGU_REG_CTRL) &
+			      ~ARCPGU_CTRL_ENABLE_MASK);
+}
+
+static const struct drm_crtc_helper_funcs arc_pgu_crtc_helper_funcs = {
+	.mode_valid	= arc_pgu_crtc_mode_valid,
+	.mode_set_nofb	= arc_pgu_crtc_mode_set_nofb,
+	.atomic_enable	= arc_pgu_crtc_atomic_enable,
+	.atomic_disable	= arc_pgu_crtc_atomic_disable,
+};
+
+static void arc_pgu_plane_atomic_update(struct drm_plane *plane,
+					struct drm_plane_state *state)
+{
+	struct arcpgu_drm_private *arcpgu;
+	struct drm_gem_cma_object *gem;
+
+	if (!plane->state->crtc || !plane->state->fb)
+		return;
+
+	arcpgu = crtc_to_arcpgu_priv(plane->state->crtc);
+	gem = drm_fb_cma_get_gem_obj(plane->state->fb, 0);
+	arc_pgu_write(arcpgu, ARCPGU_REG_BUF0_ADDR, gem->paddr);
+}
+
+static const struct drm_plane_helper_funcs arc_pgu_plane_helper_funcs = {
+	.atomic_update = arc_pgu_plane_atomic_update,
+};
+
+static void arc_pgu_plane_destroy(struct drm_plane *plane)
+{
+	drm_plane_cleanup(plane);
+}
+
+static const struct drm_plane_funcs arc_pgu_plane_funcs = {
+	.update_plane		= drm_atomic_helper_update_plane,
+	.disable_plane		= drm_atomic_helper_disable_plane,
+	.destroy		= arc_pgu_plane_destroy,
+	.reset			= drm_atomic_helper_plane_reset,
+	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
+};
+
+static struct drm_plane *arc_pgu_plane_init(struct drm_device *drm)
+{
+	struct arcpgu_drm_private *arcpgu = drm->dev_private;
+	struct drm_plane *plane = NULL;
+	int ret;
+
+	plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
+	if (!plane)
+		return ERR_PTR(-ENOMEM);
+
+	ret = drm_universal_plane_init(drm, plane, 0xff, &arc_pgu_plane_funcs,
+				       arc_pgu_supported_formats,
+				       ARRAY_SIZE(arc_pgu_supported_formats),
+				       NULL,
+				       DRM_PLANE_TYPE_PRIMARY, NULL);
+	if (ret)
+		return ERR_PTR(ret);
+
+	drm_plane_helper_add(plane, &arc_pgu_plane_helper_funcs);
+	arcpgu->plane = plane;
+
+	return plane;
+}
+
+int arc_pgu_setup_crtc(struct drm_device *drm)
+{
+	struct arcpgu_drm_private *arcpgu = drm->dev_private;
+	struct drm_plane *primary;
+	int ret;
+
+	primary = arc_pgu_plane_init(drm);
+	if (IS_ERR(primary))
+		return PTR_ERR(primary);
+
+	ret = drm_crtc_init_with_planes(drm, &arcpgu->crtc, primary, NULL,
+					&arc_pgu_crtc_funcs, NULL);
+	if (ret) {
+		arc_pgu_plane_destroy(primary);
+		return ret;
+	}
+
+	drm_crtc_helper_add(&arcpgu->crtc, &arc_pgu_crtc_helper_funcs);
+	return 0;
+}
diff --git a/drivers/gpu/drm/arc/arcpgu_drv.c b/drivers/gpu/drm/arc/arcpgu_drv.c
new file mode 100644
index 000000000..f164818ec
--- /dev/null
+++ b/drivers/gpu/drm/arc/arcpgu_drv.c
@@ -0,0 +1,224 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ARC PGU DRM driver.
+ *
+ * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#include <linux/clk.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_debugfs.h>
+#include <drm/drm_device.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_of.h>
+#include <drm/drm_probe_helper.h>
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/platform_device.h>
+
+#include "arcpgu.h"
+#include "arcpgu_regs.h"
+
+static const struct drm_mode_config_funcs arcpgu_drm_modecfg_funcs = {
+	.fb_create  = drm_gem_fb_create,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
+};
+
+static void arcpgu_setup_mode_config(struct drm_device *drm)
+{
+	drm_mode_config_init(drm);
+	drm->mode_config.min_width = 0;
+	drm->mode_config.min_height = 0;
+	drm->mode_config.max_width = 1920;
+	drm->mode_config.max_height = 1080;
+	drm->mode_config.funcs = &arcpgu_drm_modecfg_funcs;
+}
+
+DEFINE_DRM_GEM_CMA_FOPS(arcpgu_drm_ops);
+
+static int arcpgu_load(struct drm_device *drm)
+{
+	struct platform_device *pdev = to_platform_device(drm->dev);
+	struct arcpgu_drm_private *arcpgu;
+	struct device_node *encoder_node = NULL, *endpoint_node = NULL;
+	struct resource *res;
+	int ret;
+
+	arcpgu = devm_kzalloc(&pdev->dev, sizeof(*arcpgu), GFP_KERNEL);
+	if (arcpgu == NULL)
+		return -ENOMEM;
+
+	drm->dev_private = arcpgu;
+
+	arcpgu->clk = devm_clk_get(drm->dev, "pxlclk");
+	if (IS_ERR(arcpgu->clk))
+		return PTR_ERR(arcpgu->clk);
+
+	arcpgu_setup_mode_config(drm);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	arcpgu->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(arcpgu->regs))
+		return PTR_ERR(arcpgu->regs);
+
+	dev_info(drm->dev, "arc_pgu ID: 0x%x\n",
+		 arc_pgu_read(arcpgu, ARCPGU_REG_ID));
+
+	/* Get the optional framebuffer memory resource */
+	ret = of_reserved_mem_device_init(drm->dev);
+	if (ret && ret != -ENODEV)
+		return ret;
+
+	if (dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)))
+		return -ENODEV;
+
+	if (arc_pgu_setup_crtc(drm) < 0)
+		return -ENODEV;
+
+	/*
+	 * There is only one output port inside each device. It is linked with
+	 * encoder endpoint.
+	 */
+	endpoint_node = of_graph_get_next_endpoint(pdev->dev.of_node, NULL);
+	if (endpoint_node) {
+		encoder_node = of_graph_get_remote_port_parent(endpoint_node);
+		of_node_put(endpoint_node);
+	}
+
+	if (encoder_node) {
+		ret = arcpgu_drm_hdmi_init(drm, encoder_node);
+		of_node_put(encoder_node);
+		if (ret < 0)
+			return ret;
+	} else {
+		dev_info(drm->dev, "no encoder found. Assumed virtual LCD on simulation platform\n");
+		ret = arcpgu_drm_sim_init(drm, NULL);
+		if (ret < 0)
+			return ret;
+	}
+
+	drm_mode_config_reset(drm);
+	drm_kms_helper_poll_init(drm);
+
+	platform_set_drvdata(pdev, drm);
+	return 0;
+}
+
+static int arcpgu_unload(struct drm_device *drm)
+{
+	drm_kms_helper_poll_fini(drm);
+	drm_atomic_helper_shutdown(drm);
+	drm_mode_config_cleanup(drm);
+
+	return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+static int arcpgu_show_pxlclock(struct seq_file *m, void *arg)
+{
+	struct drm_info_node *node = (struct drm_info_node *)m->private;
+	struct drm_device *drm = node->minor->dev;
+	struct arcpgu_drm_private *arcpgu = drm->dev_private;
+	unsigned long clkrate = clk_get_rate(arcpgu->clk);
+	unsigned long mode_clock = arcpgu->crtc.mode.crtc_clock * 1000;
+
+	seq_printf(m, "hw  : %lu\n", clkrate);
+	seq_printf(m, "mode: %lu\n", mode_clock);
+	return 0;
+}
+
+static struct drm_info_list arcpgu_debugfs_list[] = {
+	{ "clocks", arcpgu_show_pxlclock, 0 },
+};
+
+static void arcpgu_debugfs_init(struct drm_minor *minor)
+{
+	drm_debugfs_create_files(arcpgu_debugfs_list,
+				 ARRAY_SIZE(arcpgu_debugfs_list),
+				 minor->debugfs_root, minor);
+}
+#endif
+
+static struct drm_driver arcpgu_drm_driver = {
+	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
+	.name = "arcpgu",
+	.desc = "ARC PGU Controller",
+	.date = "20160219",
+	.major = 1,
+	.minor = 0,
+	.patchlevel = 0,
+	.fops = &arcpgu_drm_ops,
+	DRM_GEM_CMA_DRIVER_OPS,
+#ifdef CONFIG_DEBUG_FS
+	.debugfs_init = arcpgu_debugfs_init,
+#endif
+};
+
+static int arcpgu_probe(struct platform_device *pdev)
+{
+	struct drm_device *drm;
+	int ret;
+
+	drm = drm_dev_alloc(&arcpgu_drm_driver, &pdev->dev);
+	if (IS_ERR(drm))
+		return PTR_ERR(drm);
+
+	ret = arcpgu_load(drm);
+	if (ret)
+		goto err_unref;
+
+	ret = drm_dev_register(drm, 0);
+	if (ret)
+		goto err_unload;
+
+	drm_fbdev_generic_setup(drm, 16);
+
+	return 0;
+
+err_unload:
+	arcpgu_unload(drm);
+
+err_unref:
+	drm_dev_put(drm);
+
+	return ret;
+}
+
+static int arcpgu_remove(struct platform_device *pdev)
+{
+	struct drm_device *drm = platform_get_drvdata(pdev);
+
+	drm_dev_unregister(drm);
+	arcpgu_unload(drm);
+	drm_dev_put(drm);
+
+	return 0;
+}
+
+static const struct of_device_id arcpgu_of_table[] = {
+	{.compatible = "snps,arcpgu"},
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, arcpgu_of_table);
+
+static struct platform_driver arcpgu_platform_driver = {
+	.probe = arcpgu_probe,
+	.remove = arcpgu_remove,
+	.driver = {
+		   .name = "arcpgu",
+		   .of_match_table = arcpgu_of_table,
+		   },
+};
+
+module_platform_driver(arcpgu_platform_driver);
+
+MODULE_AUTHOR("Carlos Palminha <palminha@synopsys.com>");
+MODULE_DESCRIPTION("ARC PGU DRM driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/arc/arcpgu_hdmi.c b/drivers/gpu/drm/arc/arcpgu_hdmi.c
new file mode 100644
index 000000000..52839934f
--- /dev/null
+++ b/drivers/gpu/drm/arc/arcpgu_hdmi.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ARC PGU DRM driver.
+ *
+ * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#include <drm/drm_bridge.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_encoder.h>
+#include <drm/drm_device.h>
+
+#include "arcpgu.h"
+
+static struct drm_encoder_funcs arcpgu_drm_encoder_funcs = {
+	.destroy = drm_encoder_cleanup,
+};
+
+int arcpgu_drm_hdmi_init(struct drm_device *drm, struct device_node *np)
+{
+	struct drm_encoder *encoder;
+	struct drm_bridge *bridge;
+
+	int ret = 0;
+
+	encoder = devm_kzalloc(drm->dev, sizeof(*encoder), GFP_KERNEL);
+	if (encoder == NULL)
+		return -ENOMEM;
+
+	/* Locate drm bridge from the hdmi encoder DT node */
+	bridge = of_drm_find_bridge(np);
+	if (!bridge)
+		return -EPROBE_DEFER;
+
+	encoder->possible_crtcs = 1;
+	encoder->possible_clones = 0;
+	ret = drm_encoder_init(drm, encoder, &arcpgu_drm_encoder_funcs,
+			       DRM_MODE_ENCODER_TMDS, NULL);
+	if (ret)
+		return ret;
+
+	/* Link drm_bridge to encoder */
+	ret = drm_bridge_attach(encoder, bridge, NULL, 0);
+	if (ret)
+		drm_encoder_cleanup(encoder);
+
+	return ret;
+}
diff --git a/drivers/gpu/drm/arc/arcpgu_regs.h b/drivers/gpu/drm/arc/arcpgu_regs.h
new file mode 100644
index 000000000..b689a382d
--- /dev/null
+++ b/drivers/gpu/drm/arc/arcpgu_regs.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * ARC PGU DRM driver.
+ *
+ * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#ifndef _ARC_PGU_REGS_H_
+#define _ARC_PGU_REGS_H_
+
+#define ARCPGU_REG_CTRL		0x00
+#define ARCPGU_REG_STAT		0x04
+#define ARCPGU_REG_FMT		0x10
+#define ARCPGU_REG_HSYNC	0x14
+#define ARCPGU_REG_VSYNC	0x18
+#define ARCPGU_REG_ACTIVE	0x1c
+#define ARCPGU_REG_BUF0_ADDR	0x40
+#define ARCPGU_REG_STRIDE	0x50
+#define ARCPGU_REG_START_SET	0x84
+
+#define ARCPGU_REG_ID		0x3FC
+
+#define ARCPGU_CTRL_ENABLE_MASK	0x02
+#define ARCPGU_CTRL_VS_POL_MASK	0x1
+#define ARCPGU_CTRL_VS_POL_OFST	0x3
+#define ARCPGU_CTRL_HS_POL_MASK	0x1
+#define ARCPGU_CTRL_HS_POL_OFST	0x4
+#define ARCPGU_MODE_XRGB8888	BIT(2)
+#define ARCPGU_STAT_BUSY_MASK	0x02
+
+#endif
diff --git a/drivers/gpu/drm/arc/arcpgu_sim.c b/drivers/gpu/drm/arc/arcpgu_sim.c
new file mode 100644
index 000000000..37d961668
--- /dev/null
+++ b/drivers/gpu/drm/arc/arcpgu_sim.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ARC PGU DRM driver.
+ *
+ * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_device.h>
+#include <drm/drm_probe_helper.h>
+
+#include "arcpgu.h"
+
+#define XRES_DEF	640
+#define YRES_DEF	480
+
+#define XRES_MAX	8192
+#define YRES_MAX	8192
+
+
+struct arcpgu_drm_connector {
+	struct drm_connector connector;
+};
+
+static int arcpgu_drm_connector_get_modes(struct drm_connector *connector)
+{
+	int count;
+
+	count = drm_add_modes_noedid(connector, XRES_MAX, YRES_MAX);
+	drm_set_preferred_mode(connector, XRES_DEF, YRES_DEF);
+	return count;
+}
+
+static void arcpgu_drm_connector_destroy(struct drm_connector *connector)
+{
+	drm_connector_unregister(connector);
+	drm_connector_cleanup(connector);
+}
+
+static const struct drm_connector_helper_funcs
+arcpgu_drm_connector_helper_funcs = {
+	.get_modes = arcpgu_drm_connector_get_modes,
+};
+
+static const struct drm_connector_funcs arcpgu_drm_connector_funcs = {
+	.reset = drm_atomic_helper_connector_reset,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = arcpgu_drm_connector_destroy,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static struct drm_encoder_funcs arcpgu_drm_encoder_funcs = {
+	.destroy = drm_encoder_cleanup,
+};
+
+int arcpgu_drm_sim_init(struct drm_device *drm, struct device_node *np)
+{
+	struct arcpgu_drm_connector *arcpgu_connector;
+	struct drm_encoder *encoder;
+	struct drm_connector *connector;
+	int ret;
+
+	encoder = devm_kzalloc(drm->dev, sizeof(*encoder), GFP_KERNEL);
+	if (encoder == NULL)
+		return -ENOMEM;
+
+	encoder->possible_crtcs = 1;
+	encoder->possible_clones = 0;
+
+	ret = drm_encoder_init(drm, encoder, &arcpgu_drm_encoder_funcs,
+			       DRM_MODE_ENCODER_VIRTUAL, NULL);
+	if (ret)
+		return ret;
+
+	arcpgu_connector = devm_kzalloc(drm->dev, sizeof(*arcpgu_connector),
+					GFP_KERNEL);
+	if (!arcpgu_connector) {
+		ret = -ENOMEM;
+		goto error_encoder_cleanup;
+	}
+
+	connector = &arcpgu_connector->connector;
+	drm_connector_helper_add(connector, &arcpgu_drm_connector_helper_funcs);
+
+	ret = drm_connector_init(drm, connector, &arcpgu_drm_connector_funcs,
+			DRM_MODE_CONNECTOR_VIRTUAL);
+	if (ret < 0) {
+		dev_err(drm->dev, "failed to initialize drm connector\n");
+		goto error_encoder_cleanup;
+	}
+
+	ret = drm_connector_attach_encoder(connector, encoder);
+	if (ret < 0) {
+		dev_err(drm->dev, "could not attach connector to encoder\n");
+		drm_connector_unregister(connector);
+		goto error_connector_cleanup;
+	}
+
+	return 0;
+
+error_connector_cleanup:
+	drm_connector_cleanup(connector);
+
+error_encoder_cleanup:
+	drm_encoder_cleanup(encoder);
+	return ret;
+}