drm/tve200: Add new driver for TVE200

This adds a new DRM driver for the Faraday Technology TVE200
block. This "TV Encoder" encodes a ITU-T BT.656 stream and can
be found in the StorLink SL3516 (later Cortina Systems CS3516)
as well as the Grain Media GM8180.

I do not have definitive word from anyone at Faraday that this
IP block is theirs, but it bears the hallmark of their 3-digit
version code (200) and is used in two SoCs from completely
different companies. (Grain Media was fully owned by Faraday
until it was transferred to NovoTek this january, and
Faraday did lots of work on the StorLink SoCs.)

The D-Link DIR-685 uses this in connection with the Ilitek
ILI9322 panel driver that supports BT.656 input, while the
GM8180 apparently has been used with the Cirrus Logic CS4954
digital video encoder. The oldest user seems to be
something called Techwall 2835.

This driver is heavily inspired by Eric Anholt's PL111
driver and therefore I have mentioned all the ancestor authors
in the header file.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170820100557.24991-2-linus.walleij@linaro.org

Documentation/gpu/index.rst

@@ -15,6 +15,7 @@ Linux GPU Driver Developer's Guide
    pl111
    tegra
    tinydrm
+   tve200
    vc4
    vga-switcheroo
    vgaarbiter

Documentation/gpu/tve200.rst

@@ -0,0 +1,6 @@
+==================================
+ drm/tve200 Faraday TV Encoder 200
+==================================
+
+.. kernel-doc:: drivers/gpu/drm/tve200/tve200_drv.c
+   :doc: Faraday TV Encoder 200

MAINTAINERS

@@ -4300,6 +4300,12 @@ T:	git git://anongit.freedesktop.org/drm/drm-misc
 S:	Maintained
 F:	drivers/gpu/drm/bochs/
 
+DRM DRIVER FOR FARADAY TVE200 TV ENCODER
+M:	Linus Walleij <linus.walleij@linaro.org>
+T:	git git://anongit.freedesktop.org/drm/drm-misc
+S:	Maintained
+F:	drivers/gpu/drm/tve200/
+
 DRM DRIVER FOR INTEL I810 VIDEO CARDS
 S:	Orphan / Obsolete
 F:	drivers/gpu/drm/i810/

drivers/gpu/drm/Kconfig

@@ -278,6 +278,8 @@ source "drivers/gpu/drm/tinydrm/Kconfig"
 
 source "drivers/gpu/drm/pl111/Kconfig"
 
+source "drivers/gpu/drm/tve200/Kconfig"
+
 # Keep legacy drivers last
 
 menuconfig DRM_LEGACY

drivers/gpu/drm/Makefile

@@ -100,3 +100,4 @@ obj-$(CONFIG_DRM_ZTE)	+= zte/
 obj-$(CONFIG_DRM_MXSFB)	+= mxsfb/
 obj-$(CONFIG_DRM_TINYDRM) += tinydrm/
 obj-$(CONFIG_DRM_PL111) += pl111/
+obj-$(CONFIG_DRM_TVE200) += tve200/

drivers/gpu/drm/tve200/Kconfig

@@ -0,0 +1,15 @@
+config DRM_TVE200
+	tristate "DRM Support for Faraday TV Encoder TVE200"
+	depends on DRM
+	depends on CMA
+	depends on ARM || COMPILE_TEST
+	depends on OF
+	select DRM_PANEL
+	select DRM_KMS_HELPER
+	select DRM_KMS_CMA_HELPER
+	select DRM_GEM_CMA_HELPER
+	select VT_HW_CONSOLE_BINDING if FRAMEBUFFER_CONSOLE
+	help
+	  Choose this option for DRM support for the Faraday TV Encoder
+	  TVE200 Controller.
+	  If M is selected the module will be called tve200_drm.

drivers/gpu/drm/tve200/Makefile

@@ -0,0 +1,5 @@
+tve200_drm-y +=	tve200_connector.o \
+		tve200_display.o \
+		tve200_drv.o
+
+obj-$(CONFIG_DRM_TVE200) += tve200_drm.o

drivers/gpu/drm/tve200/tve200_connector.c

@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ * Parts of this file were based on sources as follows:
+ *
+ * Copyright (C) 2006-2008 Intel Corporation
+ * Copyright (C) 2007 Amos Lee <amos_lee@storlinksemi.com>
+ * Copyright (C) 2007 Dave Airlie <airlied@linux.ie>
+ * Copyright (C) 2011 Texas Instruments
+ * Copyright (C) 2017 Eric Anholt
+ *
+ * This program is free software and is provided to you under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation, and any use by you of this program is subject to the terms of
+ * such GNU licence.
+ */
+
+/**
+ * tve200_drm_connector.c
+ * Implementation of the connector functions for the Faraday TV Encoder
+ */
+#include <linux/version.h>
+#include <linux/shmem_fs.h>
+#include <linux/dma-buf.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+
+#include "tve200_drm.h"
+
+static void tve200_connector_destroy(struct drm_connector *connector)
+{
+	struct tve200_drm_connector *tve200con =
+		to_tve200_connector(connector);
+
+	if (tve200con->panel)
+		drm_panel_detach(tve200con->panel);
+
+	drm_connector_unregister(connector);
+	drm_connector_cleanup(connector);
+}
+
+static enum drm_connector_status tve200_connector_detect(struct drm_connector
+							*connector, bool force)
+{
+	struct tve200_drm_connector *tve200con =
+		to_tve200_connector(connector);
+
+	return (tve200con->panel ?
+		connector_status_connected :
+		connector_status_disconnected);
+}
+
+static int tve200_connector_helper_get_modes(struct drm_connector *connector)
+{
+	struct tve200_drm_connector *tve200con =
+		to_tve200_connector(connector);
+
+	if (!tve200con->panel)
+		return 0;
+
+	return drm_panel_get_modes(tve200con->panel);
+}
+
+static const struct drm_connector_funcs connector_funcs = {
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = tve200_connector_destroy,
+	.detect = tve200_connector_detect,
+	.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 const struct drm_connector_helper_funcs connector_helper_funcs = {
+	.get_modes = tve200_connector_helper_get_modes,
+};
+
+/*
+ * Walks the OF graph to find the panel node and then asks DRM to look
+ * up the panel.
+ */
+static struct drm_panel *tve200_get_panel(struct device *dev)
+{
+	struct device_node *endpoint, *panel_node;
+	struct device_node *np = dev->of_node;
+	struct drm_panel *panel;
+
+	endpoint = of_graph_get_next_endpoint(np, NULL);
+	if (!endpoint) {
+		dev_err(dev, "no endpoint to fetch panel\n");
+		return NULL;
+	}
+
+	/* Don't proceed if we have an endpoint but no panel_node tied to it */
+	panel_node = of_graph_get_remote_port_parent(endpoint);
+	of_node_put(endpoint);
+	if (!panel_node) {
+		dev_err(dev, "no valid panel node\n");
+		return NULL;
+	}
+
+	panel = of_drm_find_panel(panel_node);
+	of_node_put(panel_node);
+
+	return panel;
+}
+
+int tve200_connector_init(struct drm_device *dev)
+{
+	struct tve200_drm_dev_private *priv = dev->dev_private;
+	struct tve200_drm_connector *tve200con = &priv->connector;
+	struct drm_connector *connector = &tve200con->connector;
+
+	drm_connector_init(dev, connector, &connector_funcs,
+			   DRM_MODE_CONNECTOR_DPI);
+	drm_connector_helper_add(connector, &connector_helper_funcs);
+
+	tve200con->panel = tve200_get_panel(dev->dev);
+	if (tve200con->panel)
+		drm_panel_attach(tve200con->panel, connector);
+
+	return 0;
+}

drivers/gpu/drm/tve200/tve200_display.c

@@ -0,0 +1,344 @@
+/*
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ * Parts of this file were based on sources as follows:
+ *
+ * Copyright (C) 2006-2008 Intel Corporation
+ * Copyright (C) 2007 Amos Lee <amos_lee@storlinksemi.com>
+ * Copyright (C) 2007 Dave Airlie <airlied@linux.ie>
+ * Copyright (C) 2011 Texas Instruments
+ * Copyright (C) 2017 Eric Anholt
+ *
+ * This program is free software and is provided to you under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation, and any use by you of this program is subject to the terms of
+ * such GNU licence.
+ */
+#include <linux/clk.h>
+#include <linux/version.h>
+#include <linux/dma-buf.h>
+#include <linux/of_graph.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+
+#include "tve200_drm.h"
+
+irqreturn_t tve200_irq(int irq, void *data)
+{
+	struct tve200_drm_dev_private *priv = data;
+	u32 stat;
+	u32 val;
+
+	stat = readl(priv->regs + TVE200_INT_STAT);
+
+	if (!stat)
+		return IRQ_NONE;
+
+	/*
+	 * Vblank IRQ
+	 *
+	 * The hardware is a bit tilted: the line stays high after clearing
+	 * the vblank IRQ, firing many more interrupts. We counter this
+	 * by toggling the IRQ back and forth from firing at vblank and
+	 * firing at start of active image, which works around the problem
+	 * since those occur strictly in sequence, and we get two IRQs for each
+	 * frame, one at start of Vblank (that we make call into the CRTC) and
+	 * another one at the start of the image (that we discard).
+	 */
+	if (stat & TVE200_INT_V_STATUS) {
+		val = readl(priv->regs + TVE200_CTRL);
+		/* We have an actual start of vsync */
+		if (!(val & TVE200_VSTSTYPE_BITS)) {
+			drm_crtc_handle_vblank(&priv->pipe.crtc);
+			/* Toggle trigger to start of active image */
+			val |= TVE200_VSTSTYPE_VAI;
+		} else {
+			/* Toggle trigger back to start of vsync */
+			val &= ~TVE200_VSTSTYPE_BITS;
+		}
+		writel(val, priv->regs + TVE200_CTRL);
+	} else
+		dev_err(priv->drm->dev, "stray IRQ %08x\n", stat);
+
+	/* Clear the interrupt once done */
+	writel(stat, priv->regs + TVE200_INT_CLR);
+
+	return IRQ_HANDLED;
+}
+
+static int tve200_display_check(struct drm_simple_display_pipe *pipe,
+			       struct drm_plane_state *pstate,
+			       struct drm_crtc_state *cstate)
+{
+	const struct drm_display_mode *mode = &cstate->mode;
+	struct drm_framebuffer *old_fb = pipe->plane.state->fb;
+	struct drm_framebuffer *fb = pstate->fb;
+
+	/*
+	 * We support these specific resolutions and nothing else.
+	 */
+	if (!(mode->hdisplay == 352 && mode->vdisplay == 240) && /* SIF(525) */
+	    !(mode->hdisplay == 352 && mode->vdisplay == 288) && /* CIF(625) */
+	    !(mode->hdisplay == 640 && mode->vdisplay == 480) && /* VGA */
+	    !(mode->hdisplay == 720 && mode->vdisplay == 480) && /* D1 */
+	    !(mode->hdisplay == 720 && mode->vdisplay == 576)) { /* D1 */
+		DRM_DEBUG_KMS("unsupported display mode (%u x %u)\n",
+			mode->hdisplay, mode->vdisplay);
+		return -EINVAL;
+	}
+
+	if (fb) {
+		u32 offset = drm_fb_cma_get_gem_addr(fb, pstate, 0);
+
+		/* FB base address must be dword aligned. */
+		if (offset & 3) {
+			DRM_DEBUG_KMS("FB not 32-bit aligned\n");
+			return -EINVAL;
+		}
+
+		/*
+		 * There's no pitch register, the mode's hdisplay
+		 * controls this.
+		 */
+		if (fb->pitches[0] != mode->hdisplay * fb->format->cpp[0]) {
+			DRM_DEBUG_KMS("can't handle pitches\n");
+			return -EINVAL;
+		}
+
+		/*
+		 * We can't change the FB format in a flicker-free
+		 * manner (and only update it during CRTC enable).
+		 */
+		if (old_fb && old_fb->format != fb->format)
+			cstate->mode_changed = true;
+	}
+
+	return 0;
+}
+
+static void tve200_display_enable(struct drm_simple_display_pipe *pipe,
+				 struct drm_crtc_state *cstate)
+{
+	struct drm_crtc *crtc = &pipe->crtc;
+	struct drm_plane *plane = &pipe->plane;
+	struct drm_device *drm = crtc->dev;
+	struct tve200_drm_dev_private *priv = drm->dev_private;
+	const struct drm_display_mode *mode = &cstate->mode;
+	struct drm_framebuffer *fb = plane->state->fb;
+	struct drm_connector *connector = &priv->connector.connector;
+	u32 format = fb->format->format;
+	u32 ctrl1 = 0;
+
+	clk_prepare_enable(priv->clk);
+
+	/* Function 1 */
+	ctrl1 |= TVE200_CTRL_CSMODE;
+	/* Interlace mode for CCIR656: parameterize? */
+	ctrl1 |= TVE200_CTRL_NONINTERLACE;
+	/* 32 words per burst */
+	ctrl1 |= TVE200_CTRL_BURST_32_WORDS;
+	/* 16 retries */
+	ctrl1 |= TVE200_CTRL_RETRYCNT_16;
+	/* NTSC mode: parametrize? */
+	ctrl1 |= TVE200_CTRL_NTSC;
+
+	/* Vsync IRQ at start of Vsync at first */
+	ctrl1 |= TVE200_VSTSTYPE_VSYNC;
+
+	if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_NEGEDGE)
+		ctrl1 |= TVE200_CTRL_TVCLKP;
+
+	if ((mode->hdisplay == 352 && mode->vdisplay == 240) || /* SIF(525) */
+	    (mode->hdisplay == 352 && mode->vdisplay == 288)) { /* CIF(625) */
+		ctrl1 |= TVE200_CTRL_IPRESOL_CIF;
+		dev_info(drm->dev, "CIF mode\n");
+	} else if (mode->hdisplay == 640 && mode->vdisplay == 480) {
+		ctrl1 |= TVE200_CTRL_IPRESOL_VGA;
+		dev_info(drm->dev, "VGA mode\n");
+	} else if ((mode->hdisplay == 720 && mode->vdisplay == 480) ||
+		   (mode->hdisplay == 720 && mode->vdisplay == 576)) {
+		ctrl1 |= TVE200_CTRL_IPRESOL_D1;
+		dev_info(drm->dev, "D1 mode\n");
+	}
+
+	if (format & DRM_FORMAT_BIG_ENDIAN) {
+		ctrl1 |= TVE200_CTRL_BBBP;
+		format &= ~DRM_FORMAT_BIG_ENDIAN;
+	}
+
+	switch (format) {
+	case DRM_FORMAT_XRGB8888:
+		ctrl1 |= TVE200_IPDMOD_RGB888;
+		break;
+	case DRM_FORMAT_RGB565:
+		ctrl1 |= TVE200_IPDMOD_RGB565;
+		break;
+	case DRM_FORMAT_XRGB1555:
+		ctrl1 |= TVE200_IPDMOD_RGB555;
+		break;
+	case DRM_FORMAT_XBGR8888:
+		ctrl1 |= TVE200_IPDMOD_RGB888 | TVE200_BGR;
+		break;
+	case DRM_FORMAT_BGR565:
+		ctrl1 |= TVE200_IPDMOD_RGB565 | TVE200_BGR;
+		break;
+	case DRM_FORMAT_XBGR1555:
+		ctrl1 |= TVE200_IPDMOD_RGB555 | TVE200_BGR;
+		break;
+	case DRM_FORMAT_YUYV:
+		ctrl1 |= TVE200_IPDMOD_YUV422;
+		ctrl1 |= TVE200_CTRL_YCBCRODR_CR0Y1CB0Y0;
+		break;
+	case DRM_FORMAT_YVYU:
+		ctrl1 |= TVE200_IPDMOD_YUV422;
+		ctrl1 |= TVE200_CTRL_YCBCRODR_CB0Y1CR0Y0;
+		break;
+	case DRM_FORMAT_UYVY:
+		ctrl1 |= TVE200_IPDMOD_YUV422;
+		ctrl1 |= TVE200_CTRL_YCBCRODR_Y1CR0Y0CB0;
+		break;
+	case DRM_FORMAT_VYUY:
+		ctrl1 |= TVE200_IPDMOD_YUV422;
+		ctrl1 |= TVE200_CTRL_YCBCRODR_Y1CB0Y0CR0;
+		break;
+	case DRM_FORMAT_YUV420:
+		ctrl1 |= TVE200_CTRL_YUV420;
+		ctrl1 |= TVE200_IPDMOD_YUV420;
+		break;
+	default:
+		dev_err(drm->dev, "Unknown FB format 0x%08x\n",
+			fb->format->format);
+		break;
+	}
+
+	ctrl1 |= TVE200_TVEEN;
+
+	drm_panel_prepare(priv->connector.panel);
+
+	/* Turn it on */
+	writel(ctrl1, priv->regs + TVE200_CTRL);
+
+	drm_panel_enable(priv->connector.panel);
+
+	drm_crtc_vblank_on(crtc);
+}
+
+void tve200_display_disable(struct drm_simple_display_pipe *pipe)
+{
+	struct drm_crtc *crtc = &pipe->crtc;
+	struct drm_device *drm = crtc->dev;
+	struct tve200_drm_dev_private *priv = drm->dev_private;
+
+	drm_crtc_vblank_off(crtc);
+
+	drm_panel_disable(priv->connector.panel);
+
+	/* Disable and Power Down */
+	writel(0, priv->regs + TVE200_CTRL);
+
+	drm_panel_unprepare(priv->connector.panel);
+
+	clk_disable_unprepare(priv->clk);
+}
+
+static void tve200_display_update(struct drm_simple_display_pipe *pipe,
+				 struct drm_plane_state *old_pstate)
+{
+	struct drm_crtc *crtc = &pipe->crtc;
+	struct drm_device *drm = crtc->dev;
+	struct tve200_drm_dev_private *priv = drm->dev_private;
+	struct drm_pending_vblank_event *event = crtc->state->event;
+	struct drm_plane *plane = &pipe->plane;
+	struct drm_plane_state *pstate = plane->state;
+	struct drm_framebuffer *fb = pstate->fb;
+
+	if (fb) {
+		/* For RGB, the Y component is used as base address */
+		writel(drm_fb_cma_get_gem_addr(fb, pstate, 0),
+		       priv->regs + TVE200_Y_FRAME_BASE_ADDR);
+
+		/* For three plane YUV we need two more addresses */
+		if (fb->format->format == DRM_FORMAT_YUV420) {
+			writel(drm_fb_cma_get_gem_addr(fb, pstate, 1),
+			       priv->regs + TVE200_U_FRAME_BASE_ADDR);
+			writel(drm_fb_cma_get_gem_addr(fb, pstate, 2),
+			       priv->regs + TVE200_V_FRAME_BASE_ADDR);
+		}
+	}
+
+	if (event) {
+		crtc->state->event = NULL;
+
+		spin_lock_irq(&crtc->dev->event_lock);
+		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
+			drm_crtc_arm_vblank_event(crtc, event);
+		else
+			drm_crtc_send_vblank_event(crtc, event);
+		spin_unlock_irq(&crtc->dev->event_lock);
+	}
+}
+
+int tve200_enable_vblank(struct drm_device *drm, unsigned int crtc)
+{
+	struct tve200_drm_dev_private *priv = drm->dev_private;
+
+	writel(TVE200_INT_V_STATUS, priv->regs + TVE200_INT_EN);
+	return 0;
+}
+
+void tve200_disable_vblank(struct drm_device *drm, unsigned int crtc)
+{
+	struct tve200_drm_dev_private *priv = drm->dev_private;
+
+	writel(0, priv->regs + TVE200_INT_EN);
+}
+
+static int tve200_display_prepare_fb(struct drm_simple_display_pipe *pipe,
+				    struct drm_plane_state *plane_state)
+{
+	return drm_fb_cma_prepare_fb(&pipe->plane, plane_state);
+}
+
+const struct drm_simple_display_pipe_funcs tve200_display_funcs = {
+	.check = tve200_display_check,
+	.enable = tve200_display_enable,
+	.disable = tve200_display_disable,
+	.update = tve200_display_update,
+	.prepare_fb = tve200_display_prepare_fb,
+};
+
+int tve200_display_init(struct drm_device *drm)
+{
+	struct tve200_drm_dev_private *priv = drm->dev_private;
+	int ret;
+	static const u32 formats[] = {
+		DRM_FORMAT_XRGB8888,
+		DRM_FORMAT_XBGR8888,
+		DRM_FORMAT_RGB565,
+		DRM_FORMAT_BGR565,
+		DRM_FORMAT_XRGB1555,
+		DRM_FORMAT_XBGR1555,
+		/*
+		 * The controller actually supports any YCbCr ordering,
+		 * for packed YCbCr. This just lists the orderings that
+		 * DRM supports.
+		 */
+		DRM_FORMAT_YUYV,
+		DRM_FORMAT_YVYU,
+		DRM_FORMAT_UYVY,
+		DRM_FORMAT_VYUY,
+		/* This uses three planes */
+		DRM_FORMAT_YUV420,
+	};
+
+	ret = drm_simple_display_pipe_init(drm, &priv->pipe,
+					   &tve200_display_funcs,
+					   formats, ARRAY_SIZE(formats),
+					   &priv->connector.connector);
+	if (ret)
+		return ret;
+
+	return 0;
+}

drivers/gpu/drm/tve200/tve200_drm.h

@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ * Parts of this file were based on sources as follows:
+ *
+ * Copyright (C) 2006-2008 Intel Corporation
+ * Copyright (C) 2007 Amos Lee <amos_lee@storlinksemi.com>
+ * Copyright (C) 2007 Dave Airlie <airlied@linux.ie>
+ * Copyright (C) 2011 Texas Instruments
+ * Copyright (C) 2017 Eric Anholt
+ *
+ * This program is free software and is provided to you under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation, and any use by you of this program is subject to the terms of
+ * such GNU licence.
+ */
+
+#ifndef _TVE200_DRM_H_
+#define _TVE200_DRM_H_
+
+/* Bits 2-31 are valid physical base addresses */
+#define TVE200_Y_FRAME_BASE_ADDR	0x00
+#define TVE200_U_FRAME_BASE_ADDR	0x04
+#define TVE200_V_FRAME_BASE_ADDR	0x08
+
+#define TVE200_INT_EN			0x0C
+#define TVE200_INT_CLR			0x10
+#define TVE200_INT_STAT			0x14
+#define TVE200_INT_BUS_ERR		BIT(7)
+#define TVE200_INT_V_STATUS		BIT(6) /* vertical blank */
+#define TVE200_INT_V_NEXT_FRAME		BIT(5)
+#define TVE200_INT_U_NEXT_FRAME		BIT(4)
+#define TVE200_INT_Y_NEXT_FRAME		BIT(3)
+#define TVE200_INT_V_FIFO_UNDERRUN	BIT(2)
+#define TVE200_INT_U_FIFO_UNDERRUN	BIT(1)
+#define TVE200_INT_Y_FIFO_UNDERRUN	BIT(0)
+#define TVE200_FIFO_UNDERRUNS		(TVE200_INT_V_FIFO_UNDERRUN | \
+					 TVE200_INT_U_FIFO_UNDERRUN | \
+					 TVE200_INT_Y_FIFO_UNDERRUN)
+
+#define TVE200_CTRL			0x18
+#define TVE200_CTRL_YUV420		BIT(31)
+#define TVE200_CTRL_CSMODE		BIT(30)
+#define TVE200_CTRL_NONINTERLACE	BIT(28) /* 0 = non-interlace CCIR656 */
+#define TVE200_CTRL_TVCLKP		BIT(27) /* Inverted clock phase */
+/* Bits 24..26 define the burst size after arbitration on the bus */
+#define TVE200_CTRL_BURST_4_WORDS	(0 << 24)
+#define TVE200_CTRL_BURST_8_WORDS	(1 << 24)
+#define TVE200_CTRL_BURST_16_WORDS	(2 << 24)
+#define TVE200_CTRL_BURST_32_WORDS	(3 << 24)
+#define TVE200_CTRL_BURST_64_WORDS	(4 << 24)
+#define TVE200_CTRL_BURST_128_WORDS	(5 << 24)
+#define TVE200_CTRL_BURST_256_WORDS	(6 << 24)
+#define TVE200_CTRL_BURST_0_WORDS	(7 << 24) /* ? */
+/*
+ * Bits 16..23 is the retry count*16 before issueing a new AHB transfer
+ * on the AHB bus.
+ */
+#define TVE200_CTRL_RETRYCNT_MASK	GENMASK(23, 16)
+#define TVE200_CTRL_RETRYCNT_16		(1 << 16)
+#define TVE200_CTRL_BBBP		BIT(15) /* 0 = little-endian */
+/* Bits 12..14 define the YCbCr ordering */
+#define TVE200_CTRL_YCBCRODR_CB0Y0CR0Y1	(0 << 12)
+#define TVE200_CTRL_YCBCRODR_Y0CB0Y1CR0	(1 << 12)
+#define TVE200_CTRL_YCBCRODR_CR0Y0CB0Y1	(2 << 12)
+#define TVE200_CTRL_YCBCRODR_Y1CB0Y0CR0	(3 << 12)
+#define TVE200_CTRL_YCBCRODR_CR0Y1CB0Y0	(4 << 12)
+#define TVE200_CTRL_YCBCRODR_Y1CR0Y0CB0	(5 << 12)
+#define TVE200_CTRL_YCBCRODR_CB0Y1CR0Y0	(6 << 12)
+#define TVE200_CTRL_YCBCRODR_Y0CR0Y1CB0	(7 << 12)
+/* Bits 10..11 define the input resolution (framebuffer size) */
+#define TVE200_CTRL_IPRESOL_CIF		(0 << 10)
+#define TVE200_CTRL_IPRESOL_VGA		(1 << 10)
+#define TVE200_CTRL_IPRESOL_D1		(2 << 10)
+#define TVE200_CTRL_NTSC		BIT(9) /* 0 = PAL, 1 = NTSC */
+#define TVE200_CTRL_INTERLACE		BIT(8) /* 1 = interlace, only for D1 */
+#define TVE200_IPDMOD_RGB555		(0 << 6) /* TVE200_CTRL_YUV420 = 0 */
+#define TVE200_IPDMOD_RGB565		(1 << 6)
+#define TVE200_IPDMOD_RGB888		(2 << 6)
+#define TVE200_IPDMOD_YUV420		(2 << 6) /* TVE200_CTRL_YUV420 = 1 */
+#define TVE200_IPDMOD_YUV422		(3 << 6)
+/* Bits 4 & 5 define when to fire the vblank IRQ */
+#define TVE200_VSTSTYPE_VSYNC		(0 << 4) /* start of vsync */
+#define TVE200_VSTSTYPE_VBP		(1 << 4) /* start of v back porch */
+#define TVE200_VSTSTYPE_VAI		(2 << 4) /* start of v active image */
+#define TVE200_VSTSTYPE_VFP		(3 << 4) /* start of v front porch */
+#define TVE200_VSTSTYPE_BITS		(BIT(4) | BIT(5))
+#define TVE200_BGR			BIT(1) /* 0 = RGB, 1 = BGR */
+#define TVE200_TVEEN			BIT(0) /* Enable TVE block */
+
+#define TVE200_CTRL_2			0x1c
+#define TVE200_CTRL_3			0x20
+
+#define TVE200_CTRL_4			0x24
+#define TVE200_CTRL_4_RESET		BIT(0) /* triggers reset of TVE200 */
+
+#include <drm/drm_gem.h>
+#include <drm/drm_simple_kms_helper.h>
+
+struct tve200_drm_connector {
+	struct drm_connector connector;
+	struct drm_panel *panel;
+};
+
+struct tve200_drm_dev_private {
+	struct drm_device *drm;
+
+	struct tve200_drm_connector connector;
+	struct drm_simple_display_pipe pipe;
+	struct drm_fbdev_cma *fbdev;
+
+	void *regs;
+	struct clk *pclk;
+	struct clk *clk;
+};
+
+#define to_tve200_connector(x) \
+	container_of(x, struct tve200_drm_connector, connector)
+
+int tve200_display_init(struct drm_device *dev);
+int tve200_enable_vblank(struct drm_device *drm, unsigned int crtc);
+void tve200_disable_vblank(struct drm_device *drm, unsigned int crtc);
+irqreturn_t tve200_irq(int irq, void *data);
+int tve200_connector_init(struct drm_device *dev);
+int tve200_encoder_init(struct drm_device *dev);
+int tve200_dumb_create(struct drm_file *file_priv,
+		      struct drm_device *dev,
+		      struct drm_mode_create_dumb *args);
+
+#endif /* _TVE200_DRM_H_ */

drivers/gpu/drm/tve200/tve200_drv.c

@@ -0,0 +1,278 @@
+/*
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ * Parts of this file were based on sources as follows:
+ *
+ * Copyright (C) 2006-2008 Intel Corporation
+ * Copyright (C) 2007 Amos Lee <amos_lee@storlinksemi.com>
+ * Copyright (C) 2007 Dave Airlie <airlied@linux.ie>
+ * Copyright (C) 2011 Texas Instruments
+ * Copyright (C) 2017 Eric Anholt
+ *
+ * This program is free software and is provided to you under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation, and any use by you of this program is subject to the terms of
+ * such GNU licence.
+ */
+
+/**
+ * DOC: Faraday TV Encoder TVE200 DRM Driver
+ *
+ * The Faraday TV Encoder TVE200 is also known as the Gemini TV Interface
+ * Controller (TVC) and is found in the Gemini Chipset from Storlink
+ * Semiconductor (later Storm Semiconductor, later Cortina Systems)
+ * but also in the Grain Media GM8180 chipset. On the Gemini the module
+ * is connected to 8 data lines and a single clock line, comprising an
+ * 8-bit BT.656 interface.
+ *
+ * This is a very basic YUV display driver. The datasheet specifies that
+ * it supports the ITU BT.656 standard. It requires a 27 MHz clock which is
+ * the hallmark of any TV encoder supporting both PAL and NTSC.
+ *
+ * This driver exposes a standard KMS interface for this TV encoder.
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-buf.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/shmem_fs.h>
+#include <linux/slab.h>
+#include <linux/version.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_panel.h>
+
+#include "tve200_drm.h"
+
+#define DRIVER_DESC      "DRM module for Faraday TVE200"
+
+static const struct drm_mode_config_funcs mode_config_funcs = {
+	.fb_create = drm_fb_cma_create,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
+};
+
+static int tve200_modeset_init(struct drm_device *dev)
+{
+	struct drm_mode_config *mode_config;
+	struct tve200_drm_dev_private *priv = dev->dev_private;
+	int ret = 0;
+
+	drm_mode_config_init(dev);
+	mode_config = &dev->mode_config;
+	mode_config->funcs = &mode_config_funcs;
+	mode_config->min_width = 352;
+	mode_config->max_width = 720;
+	mode_config->min_height = 240;
+	mode_config->max_height = 576;
+
+	ret = tve200_connector_init(dev);
+	if (ret) {
+		dev_err(dev->dev, "Failed to create tve200_drm_connector\n");
+		goto out_config;
+	}
+
+	/*
+	 * Don't actually attach if we didn't find a drm_panel
+	 * attached to us.
+	 */
+	if (!priv->connector.panel) {
+		dev_info(dev->dev,
+			 "deferring due to lack of DRM panel device\n");
+		ret = -EPROBE_DEFER;
+		goto out_config;
+	}
+	dev_info(dev->dev, "attached to panel %s\n",
+		 dev_name(priv->connector.panel->dev));
+
+	ret = tve200_display_init(dev);
+	if (ret) {
+		dev_err(dev->dev, "failed to init display\n");
+		goto out_config;
+	}
+
+	ret = drm_vblank_init(dev, 1);
+	if (ret) {
+		dev_err(dev->dev, "failed to init vblank\n");
+		goto out_config;
+	}
+
+	drm_mode_config_reset(dev);
+
+	/*
+	 * Passing in 16 here will make the RGB656 mode the default
+	 * Passing in 32 will use XRGB8888 mode
+	 */
+	priv->fbdev = drm_fbdev_cma_init(dev, 16,
+					 dev->mode_config.num_connector);
+	drm_kms_helper_poll_init(dev);
+
+	goto finish;
+
+out_config:
+	drm_mode_config_cleanup(dev);
+finish:
+	return ret;
+}
+
+DEFINE_DRM_GEM_CMA_FOPS(drm_fops);
+
+static void tve200_lastclose(struct drm_device *dev)
+{
+	struct tve200_drm_dev_private *priv = dev->dev_private;
+
+	drm_fbdev_cma_restore_mode(priv->fbdev);
+}
+
+static struct drm_driver tve200_drm_driver = {
+	.driver_features =
+		DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME | DRIVER_ATOMIC,
+	.lastclose = tve200_lastclose,
+	.ioctls = NULL,
+	.fops = &drm_fops,
+	.name = "tve200",
+	.desc = DRIVER_DESC,
+	.date = "20170703",
+	.major = 1,
+	.minor = 0,
+	.patchlevel = 0,
+	.dumb_create = drm_gem_cma_dumb_create,
+	.gem_free_object_unlocked = drm_gem_cma_free_object,
+	.gem_vm_ops = &drm_gem_cma_vm_ops,
+
+	.enable_vblank = tve200_enable_vblank,
+	.disable_vblank = tve200_disable_vblank,
+
+	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
+	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
+	.gem_prime_import = drm_gem_prime_import,
+	.gem_prime_export = drm_gem_prime_export,
+	.gem_prime_get_sg_table	= drm_gem_cma_prime_get_sg_table,
+	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
+	.gem_prime_vmap = drm_gem_cma_prime_vmap,
+	.gem_prime_vunmap = drm_gem_cma_prime_vunmap,
+	.gem_prime_mmap = drm_gem_cma_prime_mmap,
+};
+
+static int tve200_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct tve200_drm_dev_private *priv;
+	struct drm_device *drm;
+	struct resource *res;
+	int irq;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	drm = drm_dev_alloc(&tve200_drm_driver, dev);
+	if (IS_ERR(drm))
+		return PTR_ERR(drm);
+	platform_set_drvdata(pdev, drm);
+	priv->drm = drm;
+	drm->dev_private = priv;
+
+	/* Clock the silicon so we can access the registers */
+	priv->pclk = devm_clk_get(dev, "PCLK");
+	if (IS_ERR(priv->pclk)) {
+		dev_err(dev, "unable to get PCLK\n");
+		ret = PTR_ERR(priv->pclk);
+		goto dev_unref;
+	}
+	ret = clk_prepare_enable(priv->pclk);
+	if (ret) {
+		dev_err(dev, "failed to enable PCLK\n");
+		goto dev_unref;
+	}
+
+	/* This clock is for the pixels (27MHz) */
+	priv->clk = devm_clk_get(dev, "TVE");
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "unable to get TVE clock\n");
+		ret = PTR_ERR(priv->clk);
+		goto clk_disable;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->regs = devm_ioremap_resource(dev, res);
+	if (!priv->regs) {
+		dev_err(dev, "%s failed mmio\n", __func__);
+		ret = -EINVAL;
+		goto clk_disable;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (!irq) {
+		ret = -EINVAL;
+		goto clk_disable;
+	}
+
+	/* turn off interrupts before requesting the irq */
+	writel(0, priv->regs + TVE200_INT_EN);
+
+	ret = devm_request_irq(dev, irq, tve200_irq, 0, "tve200", priv);
+	if (ret) {
+		dev_err(dev, "failed to request irq %d\n", ret);
+		goto clk_disable;
+	}
+
+	ret = tve200_modeset_init(drm);
+	if (ret)
+		goto clk_disable;
+
+	ret = drm_dev_register(drm, 0);
+	if (ret < 0)
+		goto clk_disable;
+
+	return 0;
+
+clk_disable:
+	clk_disable_unprepare(priv->pclk);
+dev_unref:
+	drm_dev_unref(drm);
+	return ret;
+}
+
+static int tve200_remove(struct platform_device *pdev)
+{
+	struct drm_device *drm = platform_get_drvdata(pdev);
+	struct tve200_drm_dev_private *priv = drm->dev_private;
+
+	drm_dev_unregister(drm);
+	if (priv->fbdev)
+		drm_fbdev_cma_fini(priv->fbdev);
+	drm_mode_config_cleanup(drm);
+	clk_disable_unprepare(priv->pclk);
+	drm_dev_unref(drm);
+
+	return 0;
+}
+
+static const struct of_device_id tve200_of_match[] = {
+	{
+		.compatible = "faraday,tve200",
+	},
+	{},
+};
+
+static struct platform_driver tve200_driver = {
+	.driver = {
+		.name           = "tve200",
+		.of_match_table = of_match_ptr(tve200_of_match),
+	},
+	.probe = tve200_probe,
+	.remove = tve200_remove,
+};
+module_platform_driver(tve200_driver);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
+MODULE_LICENSE("GPL");