drm: Add support of ARC PGU display controller

ARC PGU could be found on some development boards from Synopsys.
This is a simple byte streamer that reads data from a framebuffer
and sends data to the single encoder.

Signed-off-by: Carlos Palminha <palminha@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-snps-arc@lists.infradead.org

drivers/gpu/drm/Kconfig

@@ -281,3 +281,5 @@ source "drivers/gpu/drm/imx/Kconfig"
 source "drivers/gpu/drm/vc4/Kconfig"
 
 source "drivers/gpu/drm/etnaviv/Kconfig"
+
+source "drivers/gpu/drm/arc/Kconfig"

drivers/gpu/drm/Makefile

@@ -78,3 +78,4 @@ obj-y			+= panel/
 obj-y			+= bridge/
 obj-$(CONFIG_DRM_FSL_DCU) += fsl-dcu/
 obj-$(CONFIG_DRM_ETNAVIV) += etnaviv/
+obj-$(CONFIG_DRM_ARCPGU)+= arc/

drivers/gpu/drm/arc/Kconfig

@@ -0,0 +1,10 @@
+config DRM_ARCPGU
+	tristate "ARC PGU"
+	depends on DRM && OF
+	select DRM_KMS_CMA_HELPER
+	select DRM_KMS_FB_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.

drivers/gpu/drm/arc/Makefile

@@ -0,0 +1,2 @@
+arcpgu-y := arcpgu_crtc.o arcpgu_hdmi.o arcpgu_drv.o
+obj-$(CONFIG_DRM_ARCPGU) += arcpgu.o

drivers/gpu/drm/arc/arcpgu.h

@@ -0,0 +1,50 @@
+/*
+ * ARC PGU DRM driver.
+ *
+ * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _ARCPGU_H_
+#define _ARCPGU_H_
+
+struct arcpgu_drm_private {
+	void __iomem		*regs;
+	struct clk		*clk;
+	struct drm_fbdev_cma	*fbdev;
+	struct drm_framebuffer	*fb;
+	struct list_head	event_list;
+	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);
+struct drm_fbdev_cma *arcpgu_fbdev_cma_init(struct drm_device *dev,
+	unsigned int preferred_bpp, unsigned int num_crtc,
+	unsigned int max_conn_count);
+
+#endif

drivers/gpu/drm/arc/arcpgu_crtc.c

@@ -0,0 +1,257 @@
+/*
+ * ARC PGU DRM driver.
+ *
+ * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_plane_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 struct simplefb_format supported_formats[] = {
+	{ "r5g6b5", 16, {11, 5}, {5, 6}, {0, 5}, {0, 0}, DRM_FORMAT_RGB565 },
+	{ "r8g8b8", 24, {16, 8}, {8, 8}, {0, 8}, {0, 0}, DRM_FORMAT_RGB888 },
+};
+
+static void arc_pgu_set_pxl_fmt(struct drm_crtc *crtc)
+{
+	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
+	uint32_t pixel_format = crtc->primary->state->fb->pixel_format;
+	struct simplefb_format *format = NULL;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
+		if (supported_formats[i].fourcc == pixel_format)
+			format = &supported_formats[i];
+	}
+
+	if (WARN_ON(!format))
+		return;
+
+	if (format->fourcc == DRM_FORMAT_RGB888)
+		arc_pgu_write(arcpgu, ARCPGU_REG_CTRL,
+			      arc_pgu_read(arcpgu, ARCPGU_REG_CTRL) |
+					   ARCPGU_MODE_RGB888_MASK);
+
+}
+
+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 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_enable(struct drm_crtc *crtc)
+{
+	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_disable(struct drm_crtc *crtc)
+{
+	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
+
+	if (!crtc->primary->fb)
+		return;
+
+	clk_disable_unprepare(arcpgu->clk);
+	arc_pgu_write(arcpgu, ARCPGU_REG_CTRL,
+			      arc_pgu_read(arcpgu, ARCPGU_REG_CTRL) &
+			      ~ARCPGU_CTRL_ENABLE_MASK);
+}
+
+static int arc_pgu_crtc_atomic_check(struct drm_crtc *crtc,
+				     struct drm_crtc_state *state)
+{
+	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
+	struct drm_display_mode *mode = &state->adjusted_mode;
+	long rate, clk_rate = mode->clock * 1000;
+
+	rate = clk_round_rate(arcpgu->clk, clk_rate);
+	if (rate != clk_rate)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void arc_pgu_crtc_atomic_begin(struct drm_crtc *crtc,
+				      struct drm_crtc_state *state)
+{
+	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
+	unsigned long flags;
+
+	if (crtc->state->event) {
+		struct drm_pending_vblank_event *event = crtc->state->event;
+
+		crtc->state->event = NULL;
+		event->pipe = drm_crtc_index(crtc);
+
+		WARN_ON(drm_crtc_vblank_get(crtc) != 0);
+
+		spin_lock_irqsave(&crtc->dev->event_lock, flags);
+		list_add_tail(&event->base.link, &arcpgu->event_list);
+		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
+	}
+}
+
+static const struct drm_crtc_helper_funcs arc_pgu_crtc_helper_funcs = {
+	.mode_set	= drm_helper_crtc_mode_set,
+	.mode_set_base	= drm_helper_crtc_mode_set_base,
+	.mode_set_nofb	= arc_pgu_crtc_mode_set_nofb,
+	.enable		= arc_pgu_crtc_enable,
+	.disable	= arc_pgu_crtc_disable,
+	.prepare	= arc_pgu_crtc_disable,
+	.commit		= arc_pgu_crtc_enable,
+	.atomic_check	= arc_pgu_crtc_atomic_check,
+	.atomic_begin	= arc_pgu_crtc_atomic_begin,
+};
+
+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 = {
+	.prepare_fb = NULL,
+	.cleanup_fb = NULL,
+	.atomic_update = arc_pgu_plane_atomic_update,
+};
+
+static void arc_pgu_plane_destroy(struct drm_plane *plane)
+{
+	drm_plane_helper_disable(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;
+	u32 formats[ARRAY_SIZE(supported_formats)], i;
+	int ret;
+
+	plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
+	if (!plane)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
+		formats[i] = supported_formats[i].fourcc;
+
+	ret = drm_universal_plane_init(drm, plane, 0xff, &arc_pgu_plane_funcs,
+				       formats, ARRAY_SIZE(formats),
+				       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;
+}