drm/meson: Add support for HDMI encoder and DW-HDMI bridge + PHY

The Amlogic Meson GXBB/GXL/GXM SoCs embeds a Synopsys DesignWare HDMI TX
Controller with a custom Bridge + PHY around the Controller.

This driver makes uses of all the custom PHY plat data callbacks and enables
the compatible HDMI modes to be configured as a drm_encoder instance.

Acked-by: Daniel Vetter <[e-mail]>
Signed-off-by: Neil Armstrong <[e-mail]>

drivers/gpu/drm/meson/Kconfig

···
 	select DRM_GEM_CMA_HELPER
 	select VIDEOMODE_HELPERS
 	select REGMAP_MMIO
+
+config DRM_MESON_DW_HDMI
+	tristate "HDMI Synopsys Controller support for Amlogic Meson Display"
+	depends on DRM_MESON
+	default y if DRM_MESON
+	select DRM_DW_HDMI

drivers/gpu/drm/meson/Makefile

···
 meson-drm-y += meson_viu.o meson_vpp.o meson_venc.o meson_vclk.o meson_canvas.o
 
 obj-$(CONFIG_DRM_MESON) += meson-drm.o
+obj-$(CONFIG_DRM_MESON_DW_HDMI) += meson_dw_hdmi.o

drivers/gpu/drm/meson/meson_drv.h

···
 
 	struct {
 		unsigned int current_mode;
+		bool hdmi_repeat;
+		bool venc_repeat;
+		bool hdmi_use_enci;
 	} venc;
 };
 

drivers/gpu/drm/meson/meson_dw_hdmi.c

···
+/*
+ * Copyright (C) 2016 BayLibre, SAS
+ * Author: Neil Armstrong <[e-mail]>
+ * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/component.h>
+#include <linux/of_graph.h>
+#include <linux/reset.h>
+#include <linux/clk.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/bridge/dw_hdmi.h>
+
+#include <uapi/linux/media-bus-format.h>
+#include <uapi/linux/videodev2.h>
+
+#include "meson_drv.h"
+#include "meson_venc.h"
+#include "meson_vclk.h"
+#include "meson_dw_hdmi.h"
+#include "meson_registers.h"
+
+#define DRIVER_NAME "meson-dw-hdmi"
+#define DRIVER_DESC "Amlogic Meson HDMI-TX DRM driver"
+
+/*
+ * HDMI Output is composed of :
+ * - A Synopsys DesignWare HDMI Controller IP
+ * - A TOP control block controlling the Clocks and PHY
+ * - A custom HDMI PHY in order convert video to TMDS signal
+ *  ___________________________________
+ * |            HDMI TOP               |<= HPD
+ * |___________________________________|
+ * |                  |                |
+ * |  Synopsys HDMI   |   HDMI PHY     |=> TMDS
+ * |    Controller    |________________|
+ * |___________________________________|<=> DDC
+ *
+ * The HDMI TOP block only supports HPD sensing.
+ * The Synopsys HDMI Controller interrupt is routed
+ * through the TOP Block interrupt.
+ * Communication to the TOP Block and the Synopsys
+ * HDMI Controller is done a pair of addr+read/write
+ * registers.
+ * The HDMI PHY is configured by registers in the
+ * HHI register block.
+ *
+ * Pixel data arrives in 4:4:4 format from the VENC
+ * block and the VPU HDMI mux selects either the ENCI
+ * encoder for the 576i or 480i formats or the ENCP
+ * encoder for all the other formats including
+ * interlaced HD formats.
+ * The VENC uses a DVI encoder on top of the ENCI
+ * or ENCP encoders to generate DVI timings for the
+ * HDMI controller.
+ *
+ * GXBB, GXL and GXM embeds the Synopsys DesignWare
+ * HDMI TX IP version 2.01a with HDCP and I2C & S/PDIF
+ * audio source interfaces.
+ *
+ * We handle the following features :
+ * - HPD Rise & Fall interrupt
+ * - HDMI Controller Interrupt
+ * - HDMI PHY Init for 480i to 1080p60
+ * - VENC & HDMI Clock setup for 480i to 1080p60
+ * - VENC Mode setup for 480i to 1080p60
+ *
+ * What is missing :
+ * - PHY, Clock and Mode setup for 2k && 4k modes
+ * - SDDC Scrambling mode for HDMI 2.0a
+ * - HDCP Setup
+ * - CEC Management
+ */
+
+/* TOP Block Communication Channel */
+#define HDMITX_TOP_ADDR_REG	0x0
+#define HDMITX_TOP_DATA_REG	0x4
+#define HDMITX_TOP_CTRL_REG	0x8
+
+/* Controller Communication Channel */
+#define HDMITX_DWC_ADDR_REG	0x10
+#define HDMITX_DWC_DATA_REG	0x14
+#define HDMITX_DWC_CTRL_REG	0x18
+
+/* HHI Registers */
+#define HHI_MEM_PD_REG0		0x100 /* 0x40 */
+#define HHI_HDMI_CLK_CNTL	0x1cc /* 0x73 */
+#define HHI_HDMI_PHY_CNTL0	0x3a0 /* 0xe8 */
+#define HHI_HDMI_PHY_CNTL1	0x3a4 /* 0xe9 */
+#define HHI_HDMI_PHY_CNTL2	0x3a8 /* 0xea */
+#define HHI_HDMI_PHY_CNTL3	0x3ac /* 0xeb */
+
+static DEFINE_SPINLOCK(reg_lock);
+
+enum meson_venc_source {
+	MESON_VENC_SOURCE_NONE = 0,
+	MESON_VENC_SOURCE_ENCI = 1,
+	MESON_VENC_SOURCE_ENCP = 2,
+};
+
+struct meson_dw_hdmi {
+	struct drm_encoder encoder;
+	struct dw_hdmi_plat_data dw_plat_data;
+	struct meson_drm *priv;
+	struct device *dev;
+	void __iomem *hdmitx;
+	struct reset_control *hdmitx_apb;
+	struct reset_control *hdmitx_ctrl;
+	struct reset_control *hdmitx_phy;
+	struct clk *hdmi_pclk;
+	struct clk *venci_clk;
+	u32 irq_stat;
+};
+#define encoder_to_meson_dw_hdmi(x) \
+	container_of(x, struct meson_dw_hdmi, encoder)
+
+static inline int dw_hdmi_is_compatible(struct meson_dw_hdmi *dw_hdmi,
+					const char *compat)
+{
+	return of_device_is_compatible(dw_hdmi->dev->of_node, compat);
+}
+
+/* PHY (via TOP bridge) and Controller dedicated register interface */
+
+static unsigned int dw_hdmi_top_read(struct meson_dw_hdmi *dw_hdmi,
+				     unsigned int addr)
+{
+	unsigned long flags;
+	unsigned int data;
+
+	spin_lock_irqsave(&reg_lock, flags);
+
+	/* ADDR must be written twice */
+	writel(addr & 0xffff, dw_hdmi->hdmitx + HDMITX_TOP_ADDR_REG);
+	writel(addr & 0xffff, dw_hdmi->hdmitx + HDMITX_TOP_ADDR_REG);
+
+	/* Read needs a second DATA read */
+	data = readl(dw_hdmi->hdmitx + HDMITX_TOP_DATA_REG);
+	data = readl(dw_hdmi->hdmitx + HDMITX_TOP_DATA_REG);
+
+	spin_unlock_irqrestore(&reg_lock, flags);
+
+	return data;
+}
+
+static inline void dw_hdmi_top_write(struct meson_dw_hdmi *dw_hdmi,
+				     unsigned int addr, unsigned int data)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&reg_lock, flags);
+
+	/* ADDR must be written twice */
+	writel(addr & 0xffff, dw_hdmi->hdmitx + HDMITX_TOP_ADDR_REG);
+	writel(addr & 0xffff, dw_hdmi->hdmitx + HDMITX_TOP_ADDR_REG);
+
+	/* Write needs single DATA write */
+	writel(data, dw_hdmi->hdmitx + HDMITX_TOP_DATA_REG);
+
+	spin_unlock_irqrestore(&reg_lock, flags);
+}
+
+/* Helper to change specific bits in PHY registers */
+static inline void dw_hdmi_top_write_bits(struct meson_dw_hdmi *dw_hdmi,
+					  unsigned int addr,
+					  unsigned int mask,
+					  unsigned int val)
+{
+	unsigned int data = dw_hdmi_top_read(dw_hdmi, addr);
+
+	data &= ~mask;
+	data |= val;
+
+	dw_hdmi_top_write(dw_hdmi, addr, data);
+}
+
+static unsigned int dw_hdmi_dwc_read(struct meson_dw_hdmi *dw_hdmi,
+				     unsigned int addr)
+{
+	unsigned long flags;
+	unsigned int data;
+
+	spin_lock_irqsave(&reg_lock, flags);
+
+	/* ADDR must be written twice */
+	writel(addr & 0xffff, dw_hdmi->hdmitx + HDMITX_DWC_ADDR_REG);
+	writel(addr & 0xffff, dw_hdmi->hdmitx + HDMITX_DWC_ADDR_REG);
+
+	/* Read needs a second DATA read */
+	data = readl(dw_hdmi->hdmitx + HDMITX_DWC_DATA_REG);
+	data = readl(dw_hdmi->hdmitx + HDMITX_DWC_DATA_REG);
+
+	spin_unlock_irqrestore(&reg_lock, flags);
+
+	return data;
+}
+
+static inline void dw_hdmi_dwc_write(struct meson_dw_hdmi *dw_hdmi,
+				     unsigned int addr, unsigned int data)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&reg_lock, flags);
+
+	/* ADDR must be written twice */
+	writel(addr & 0xffff, dw_hdmi->hdmitx + HDMITX_DWC_ADDR_REG);
+	writel(addr & 0xffff, dw_hdmi->hdmitx + HDMITX_DWC_ADDR_REG);
+
+	/* Write needs single DATA write */
+	writel(data, dw_hdmi->hdmitx + HDMITX_DWC_DATA_REG);
+
+	spin_unlock_irqrestore(&reg_lock, flags);
+}
+
+/* Helper to change specific bits in controller registers */
+static inline void dw_hdmi_dwc_write_bits(struct meson_dw_hdmi *dw_hdmi,
+					  unsigned int addr,
+					  unsigned int mask,
+					  unsigned int val)
+{
+	unsigned int data = dw_hdmi_dwc_read(dw_hdmi, addr);
+
+	data &= ~mask;
+	data |= val;
+
+	dw_hdmi_dwc_write(dw_hdmi, addr, data);
+}
+
+/* Bridge */
+
+/* Setup PHY bandwidth modes */
+static void meson_hdmi_phy_setup_mode(struct meson_dw_hdmi *dw_hdmi,
+				      struct drm_display_mode *mode)
+{
+	struct meson_drm *priv = dw_hdmi->priv;
+	unsigned int pixel_clock = mode->clock;
+
+	if (dw_hdmi_is_compatible(dw_hdmi, "amlogic,meson-gxl-dw-hdmi") ||
+	    dw_hdmi_is_compatible(dw_hdmi, "amlogic,meson-gxm-dw-hdmi")) {
+		if (pixel_clock >= 371250) {
+			/* 5.94Gbps, 3.7125Gbps */
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL0, 0x333d3282);
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL3, 0x2136315b);
+		} else if (pixel_clock >= 297000) {
+			/* 2.97Gbps */
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL0, 0x33303382);
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL3, 0x2036315b);
+		} else if (pixel_clock >= 148500) {
+			/* 1.485Gbps */
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL0, 0x33303362);
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL3, 0x2016315b);
+		} else {
+			/* 742.5Mbps, and below */
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL0, 0x33604142);
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL3, 0x0016315b);
+		}
+	} else if (dw_hdmi_is_compatible(dw_hdmi,
+					 "amlogic,meson-gxbb-dw-hdmi")) {
+		if (pixel_clock >= 371250) {
+			/* 5.94Gbps, 3.7125Gbps */
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL0, 0x33353245);
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL3, 0x2100115b);
+		} else if (pixel_clock >= 297000) {
+			/* 2.97Gbps */
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL0, 0x33634283);
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL3, 0xb000115b);
+		} else {
+			/* 1.485Gbps, and below */
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL0, 0x33632122);
+			regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL3, 0x2000115b);
+		}
+	}
+}
+
+static inline void dw_hdmi_phy_reset(struct meson_dw_hdmi *dw_hdmi)
+{
+	struct meson_drm *priv = dw_hdmi->priv;
+
+	/* Enable and software reset */
+	regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1, 0xf, 0xf);
+
+	mdelay(2);
+
+	/* Enable and unreset */
+	regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1, 0xf, 0xe);
+
+	mdelay(2);
+}
+
+static void dw_hdmi_set_vclk(struct meson_dw_hdmi *dw_hdmi,
+			     struct drm_display_mode *mode)
+{
+	struct meson_drm *priv = dw_hdmi->priv;
+	int vic = drm_match_cea_mode(mode);
+	unsigned int vclk_freq;
+	unsigned int venc_freq;
+	unsigned int hdmi_freq;
+
+	vclk_freq = mode->clock;
+
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		vclk_freq *= 2;
+
+	venc_freq = vclk_freq;
+	hdmi_freq = vclk_freq;
+
+	if (meson_venc_hdmi_venc_repeat(vic))
+		venc_freq *= 2;
+
+	vclk_freq = max(venc_freq, hdmi_freq);
+
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		venc_freq /= 2;
+
+	DRM_DEBUG_DRIVER("vclk:%d venc=%d hdmi=%d enci=%d\n",
+		vclk_freq, venc_freq, hdmi_freq,
+		priv->venc.hdmi_use_enci);
+
+	meson_vclk_setup(priv, MESON_VCLK_TARGET_HDMI, vclk_freq,
+			 venc_freq, hdmi_freq, priv->venc.hdmi_use_enci);
+}
+
+static int dw_hdmi_phy_init(struct dw_hdmi *hdmi, void *data,
+			    struct drm_display_mode *mode)
+{
+	struct meson_dw_hdmi *dw_hdmi = (struct meson_dw_hdmi *)data;
+	struct meson_drm *priv = dw_hdmi->priv;
+	unsigned int wr_clk =
+		readl_relaxed(priv->io_base + _REG(VPU_HDMI_SETTING));
+
+	DRM_DEBUG_DRIVER("%d:\"%s\"\n", mode->base.id, mode->name);
+
+	/* Enable clocks */
+	regmap_update_bits(priv->hhi, HHI_HDMI_CLK_CNTL, 0xffff, 0x100);
+
+	/* Bring HDMITX MEM output of power down */
+	regmap_update_bits(priv->hhi, HHI_MEM_PD_REG0, 0xff << 8, 0);
+
+	/* Bring out of reset */
+	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_SW_RESET,  0);
+
+	/* Enable internal pixclk, tmds_clk, spdif_clk, i2s_clk, cecclk */
+	dw_hdmi_top_write_bits(dw_hdmi, HDMITX_TOP_CLK_CNTL,
+			       0x3, 0x3);
+	dw_hdmi_top_write_bits(dw_hdmi, HDMITX_TOP_CLK_CNTL,
+			       0x3 << 4, 0x3 << 4);
+
+	/* Enable normal output to PHY */
+	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_BIST_CNTL, BIT(12));
+
+	/* TMDS pattern setup (TOFIX pattern for 4k2k scrambling) */
+	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_01, 0x001f001f);
+	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_23, 0x001f001f);
+
+	/* Load TMDS pattern */
+	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_CNTL, 0x1);
+	msleep(20);
+	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_CNTL, 0x2);
+
+	/* Setup PHY parameters */
+	meson_hdmi_phy_setup_mode(dw_hdmi, mode);
+
+	/* Setup PHY */
+	regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1,
+			   0xffff << 16, 0x0390 << 16);
+
+	/* BIT_INVERT */
+	if (dw_hdmi_is_compatible(dw_hdmi, "amlogic,meson-gxl-dw-hdmi") ||
+	    dw_hdmi_is_compatible(dw_hdmi, "amlogic,meson-gxm-dw-hdmi"))
+		regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1,
+				   BIT(17), 0);
+	else
+		regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1,
+				   BIT(17), BIT(17));
+
+	/* Disable clock, fifo, fifo_wr */
+	regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1, 0xf, 0);
+
+	msleep(100);
+
+	/* Reset PHY 3 times in a row */
+	dw_hdmi_phy_reset(dw_hdmi);
+	dw_hdmi_phy_reset(dw_hdmi);
+	dw_hdmi_phy_reset(dw_hdmi);
+
+	/* Temporary Disable VENC video stream */
+	if (priv->venc.hdmi_use_enci)
+		writel_relaxed(0, priv->io_base + _REG(ENCI_VIDEO_EN));
+	else
+		writel_relaxed(0, priv->io_base + _REG(ENCP_VIDEO_EN));
+
+	/* Temporary Disable HDMI video stream to HDMI-TX */
+	writel_bits_relaxed(0x3, 0,
+			    priv->io_base + _REG(VPU_HDMI_SETTING));
+	writel_bits_relaxed(0xf << 8, 0,
+			    priv->io_base + _REG(VPU_HDMI_SETTING));
+
+	/* Re-Enable VENC video stream */
+	if (priv->venc.hdmi_use_enci)
+		writel_relaxed(1, priv->io_base + _REG(ENCI_VIDEO_EN));
+	else
+		writel_relaxed(1, priv->io_base + _REG(ENCP_VIDEO_EN));
+
+	/* Push back HDMI clock settings */
+	writel_bits_relaxed(0xf << 8, wr_clk & (0xf << 8),
+			    priv->io_base + _REG(VPU_HDMI_SETTING));
+
+	/* Enable and Select HDMI video source for HDMI-TX */
+	if (priv->venc.hdmi_use_enci)
+		writel_bits_relaxed(0x3, MESON_VENC_SOURCE_ENCI,
+				    priv->io_base + _REG(VPU_HDMI_SETTING));
+	else
+		writel_bits_relaxed(0x3, MESON_VENC_SOURCE_ENCP,
+				    priv->io_base + _REG(VPU_HDMI_SETTING));
+
+	return 0;
+}
+
+static void dw_hdmi_phy_disable(struct dw_hdmi *hdmi,
+				void *data)
+{
+	struct meson_dw_hdmi *dw_hdmi = (struct meson_dw_hdmi *)data;
+	struct meson_drm *priv = dw_hdmi->priv;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	regmap_write(priv->hhi, HHI_HDMI_PHY_CNTL0, 0);
+}
+
+static enum drm_connector_status dw_hdmi_read_hpd(struct dw_hdmi *hdmi,
+			     void *data)
+{
+	struct meson_dw_hdmi *dw_hdmi = (struct meson_dw_hdmi *)data;
+
+	return !!dw_hdmi_top_read(dw_hdmi, HDMITX_TOP_STAT0) ?
+		connector_status_connected : connector_status_disconnected;
+}
+
+static void dw_hdmi_setup_hpd(struct dw_hdmi *hdmi,
+			      void *data)
+{
+	struct meson_dw_hdmi *dw_hdmi = (struct meson_dw_hdmi *)data;
+
+	/* Setup HPD Filter */
+	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_HPD_FILTER,
+			  (0xa << 12) | 0xa0);
+
+	/* Clear interrupts */
+	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_INTR_STAT_CLR,
+			  HDMITX_TOP_INTR_HPD_RISE | HDMITX_TOP_INTR_HPD_FALL);
+
+	/* Unmask interrupts */
+	dw_hdmi_top_write_bits(dw_hdmi, HDMITX_TOP_INTR_MASKN,
+			HDMITX_TOP_INTR_HPD_RISE | HDMITX_TOP_INTR_HPD_FALL,
+			HDMITX_TOP_INTR_HPD_RISE | HDMITX_TOP_INTR_HPD_FALL);
+}
+
+static const struct dw_hdmi_phy_ops meson_dw_hdmi_phy_ops = {
+	.init = dw_hdmi_phy_init,
+	.disable = dw_hdmi_phy_disable,
+	.read_hpd = dw_hdmi_read_hpd,
+	.setup_hpd = dw_hdmi_setup_hpd,
+};
+
+static irqreturn_t dw_hdmi_top_irq(int irq, void *dev_id)
+{
+	struct meson_dw_hdmi *dw_hdmi = dev_id;
+	u32 stat;
+
+	stat = dw_hdmi_top_read(dw_hdmi, HDMITX_TOP_INTR_STAT);
+	dw_hdmi_top_write(dw_hdmi, HDMITX_TOP_INTR_STAT_CLR, stat);
+
+	/* HPD Events, handle in the threaded interrupt handler */
+	if (stat & (HDMITX_TOP_INTR_HPD_RISE | HDMITX_TOP_INTR_HPD_FALL)) {
+		dw_hdmi->irq_stat = stat;
+		return IRQ_WAKE_THREAD;
+	}
+
+	/* HDMI Controller Interrupt */
+	if (stat & 1)
+		return IRQ_NONE;
+
+	/* TOFIX Handle HDCP Interrupts */
+
+	return IRQ_HANDLED;
+}
+
+/* Threaded interrupt handler to manage HPD events */
+static irqreturn_t dw_hdmi_top_thread_irq(int irq, void *dev_id)
+{
+	struct meson_dw_hdmi *dw_hdmi = dev_id;
+	u32 stat = dw_hdmi->irq_stat;
+
+	/* HPD Events */
+	if (stat & (HDMITX_TOP_INTR_HPD_RISE | HDMITX_TOP_INTR_HPD_FALL)) {
+		bool hpd_connected = false;
+
+		if (stat & HDMITX_TOP_INTR_HPD_RISE)
+			hpd_connected = true;
+
+		dw_hdmi_setup_rx_sense(dw_hdmi->dev, hpd_connected,
+				       hpd_connected);
+
+		drm_helper_hpd_irq_event(dw_hdmi->encoder.dev);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/* TOFIX Enable support for non-vic modes */
+static enum drm_mode_status dw_hdmi_mode_valid(struct drm_connector *connector,
+					       struct drm_display_mode *mode)
+{
+	unsigned int vclk_freq;
+	unsigned int venc_freq;
+	unsigned int hdmi_freq;
+	int vic = drm_match_cea_mode(mode);
+
+	DRM_DEBUG_DRIVER("Modeline %d:\"%s\" %d %d %d %d %d %d %d %d %d %d 0x%x 0x%x\n",
+		mode->base.id, mode->name, mode->vrefresh, mode->clock,
+		mode->hdisplay, mode->hsync_start,
+		mode->hsync_end, mode->htotal,
+		mode->vdisplay, mode->vsync_start,
+		mode->vsync_end, mode->vtotal, mode->type, mode->flags);
+
+	/* For now, only accept VIC modes */
+	if (!vic)
+		return MODE_BAD;
+
+	/* For now, filter by supported VIC modes */
+	if (!meson_venc_hdmi_supported_vic(vic))
+		return MODE_BAD;
+
+	vclk_freq = mode->clock;
+
+	/* 480i/576i needs global pixel doubling */
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		vclk_freq *= 2;
+
+	venc_freq = vclk_freq;
+	hdmi_freq = vclk_freq;
+
+	/* VENC double pixels for 1080i and 720p modes */
+	if (meson_venc_hdmi_venc_repeat(vic))
+		venc_freq *= 2;
+
+	vclk_freq = max(venc_freq, hdmi_freq);
+
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		venc_freq /= 2;
+
+	dev_dbg(connector->dev->dev, "%s: vclk:%d venc=%d hdmi=%d\n", __func__,
+		vclk_freq, venc_freq, hdmi_freq);
+
+	/* Finally filter by configurable vclk frequencies */
+	switch (vclk_freq) {
+	case 54000:
+	case 74250:
+	case 148500:
+	case 297000:
+	case 594000:
+		return MODE_OK;
+	}
+
+	return MODE_CLOCK_RANGE;
+}
+
+/* Encoder */
+
+static void meson_venc_hdmi_encoder_destroy(struct drm_encoder *encoder)
+{
+	drm_encoder_cleanup(encoder);
+}
+
+static const struct drm_encoder_funcs meson_venc_hdmi_encoder_funcs = {
+	.destroy        = meson_venc_hdmi_encoder_destroy,
+};
+
+static int meson_venc_hdmi_encoder_atomic_check(struct drm_encoder *encoder,
+					struct drm_crtc_state *crtc_state,
+					struct drm_connector_state *conn_state)
+{
+	return 0;
+}
+
+static void meson_venc_hdmi_encoder_disable(struct drm_encoder *encoder)
+{
+	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
+	struct meson_drm *priv = dw_hdmi->priv;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	writel_bits_relaxed(0x3, 0,
+			    priv->io_base + _REG(VPU_HDMI_SETTING));
+
+	writel_relaxed(0, priv->io_base + _REG(ENCI_VIDEO_EN));
+	writel_relaxed(0, priv->io_base + _REG(ENCP_VIDEO_EN));
+}
+
+static void meson_venc_hdmi_encoder_enable(struct drm_encoder *encoder)
+{
+	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
+	struct meson_drm *priv = dw_hdmi->priv;
+
+	DRM_DEBUG_DRIVER("%s\n", priv->venc.hdmi_use_enci ? "VENCI" : "VENCP");
+
+	if (priv->venc.hdmi_use_enci)
+		writel_relaxed(1, priv->io_base + _REG(ENCI_VIDEO_EN));
+	else
+		writel_relaxed(1, priv->io_base + _REG(ENCP_VIDEO_EN));
+}
+
+static void meson_venc_hdmi_encoder_mode_set(struct drm_encoder *encoder,
+				   struct drm_display_mode *mode,
+				   struct drm_display_mode *adjusted_mode)
+{
+	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
+	struct meson_drm *priv = dw_hdmi->priv;
+	int vic = drm_match_cea_mode(mode);
+
+	DRM_DEBUG_DRIVER("%d:\"%s\" vic %d\n",
+			 mode->base.id, mode->name, vic);
+
+	/* Should have been filtered */
+	if (!vic)
+		return;
+
+	/* VENC + VENC-DVI Mode setup */
+	meson_venc_hdmi_mode_set(priv, vic, mode);
+
+	/* VCLK Set clock */
+	dw_hdmi_set_vclk(dw_hdmi, mode);
+
+	/* Setup YUV444 to HDMI-TX, no 10bit diphering */
+	writel_relaxed(0, priv->io_base + _REG(VPU_HDMI_FMT_CTRL));
+}
+
+static const struct drm_encoder_helper_funcs
+				meson_venc_hdmi_encoder_helper_funcs = {
+	.atomic_check	= meson_venc_hdmi_encoder_atomic_check,
+	.disable	= meson_venc_hdmi_encoder_disable,
+	.enable		= meson_venc_hdmi_encoder_enable,
+	.mode_set	= meson_venc_hdmi_encoder_mode_set,
+};
+
+/* DW HDMI Regmap */
+
+static int meson_dw_hdmi_reg_read(void *context, unsigned int reg,
+				  unsigned int *result)
+{
+	*result = dw_hdmi_dwc_read(context, reg);
+
+	return 0;
+
+}
+
+static int meson_dw_hdmi_reg_write(void *context, unsigned int reg,
+				   unsigned int val)
+{
+	dw_hdmi_dwc_write(context, reg, val);
+
+	return 0;
+}
+
+static const struct regmap_config meson_dw_hdmi_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 8,
+	.reg_read = meson_dw_hdmi_reg_read,
+	.reg_write = meson_dw_hdmi_reg_write,
+	.max_register = 0x10000,
+};
+
+static bool meson_hdmi_connector_is_available(struct device *dev)
+{
+	struct device_node *ep, *remote;
+
+	/* HDMI Connector is on the second port, first endpoint */
+	ep = of_graph_get_endpoint_by_regs(dev->of_node, 1, 0);
+	if (!ep)
+		return false;
+
+	/* If the endpoint node exists, consider it enabled */
+	remote = of_graph_get_remote_port(ep);
+	if (remote) {
+		of_node_put(ep);
+		return true;
+	}
+
+	of_node_put(ep);
+	of_node_put(remote);
+
+	return false;
+}
+
+static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
+				void *data)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct meson_dw_hdmi *meson_dw_hdmi;
+	struct drm_device *drm = data;
+	struct meson_drm *priv = drm->dev_private;
+	struct dw_hdmi_plat_data *dw_plat_data;
+	struct drm_encoder *encoder;
+	struct resource *res;
+	int irq;
+	int ret;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (!meson_hdmi_connector_is_available(dev)) {
+		dev_info(drm->dev, "HDMI Output connector not available\n");
+		return -ENODEV;
+	}
+
+	meson_dw_hdmi = devm_kzalloc(dev, sizeof(*meson_dw_hdmi),
+				     GFP_KERNEL);
+	if (!meson_dw_hdmi)
+		return -ENOMEM;
+
+	meson_dw_hdmi->priv = priv;
+	meson_dw_hdmi->dev = dev;
+	dw_plat_data = &meson_dw_hdmi->dw_plat_data;
+	encoder = &meson_dw_hdmi->encoder;
+
+	meson_dw_hdmi->hdmitx_apb = devm_reset_control_get_exclusive(dev,
+						"hdmitx_apb");
+	if (IS_ERR(meson_dw_hdmi->hdmitx_apb)) {
+		dev_err(dev, "Failed to get hdmitx_apb reset\n");
+		return PTR_ERR(meson_dw_hdmi->hdmitx_apb);
+	}
+
+	meson_dw_hdmi->hdmitx_ctrl = devm_reset_control_get_exclusive(dev,
+						"hdmitx");
+	if (IS_ERR(meson_dw_hdmi->hdmitx_ctrl)) {
+		dev_err(dev, "Failed to get hdmitx reset\n");
+		return PTR_ERR(meson_dw_hdmi->hdmitx_ctrl);
+	}
+
+	meson_dw_hdmi->hdmitx_phy = devm_reset_control_get_exclusive(dev,
+						"hdmitx_phy");
+	if (IS_ERR(meson_dw_hdmi->hdmitx_phy)) {
+		dev_err(dev, "Failed to get hdmitx_phy reset\n");
+		return PTR_ERR(meson_dw_hdmi->hdmitx_phy);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	meson_dw_hdmi->hdmitx = devm_ioremap_resource(dev, res);
+	if (IS_ERR(meson_dw_hdmi->hdmitx))
+		return PTR_ERR(meson_dw_hdmi->hdmitx);
+
+	meson_dw_hdmi->hdmi_pclk = devm_clk_get(dev, "isfr");
+	if (IS_ERR(meson_dw_hdmi->hdmi_pclk)) {
+		dev_err(dev, "Unable to get HDMI pclk\n");
+		return PTR_ERR(meson_dw_hdmi->hdmi_pclk);
+	}
+	clk_prepare_enable(meson_dw_hdmi->hdmi_pclk);
+
+	meson_dw_hdmi->venci_clk = devm_clk_get(dev, "venci");
+	if (IS_ERR(meson_dw_hdmi->venci_clk)) {
+		dev_err(dev, "Unable to get venci clk\n");
+		return PTR_ERR(meson_dw_hdmi->venci_clk);
+	}
+	clk_prepare_enable(meson_dw_hdmi->venci_clk);
+
+	dw_plat_data->regm = devm_regmap_init(dev, NULL, meson_dw_hdmi,
+					      &meson_dw_hdmi_regmap_config);
+	if (IS_ERR(dw_plat_data->regm))
+		return PTR_ERR(dw_plat_data->regm);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "Failed to get hdmi top irq\n");
+		return irq;
+	}
+
+	ret = devm_request_threaded_irq(dev, irq, dw_hdmi_top_irq,
+					dw_hdmi_top_thread_irq, IRQF_SHARED,
+					"dw_hdmi_top_irq", meson_dw_hdmi);
+	if (ret) {
+		dev_err(dev, "Failed to request hdmi top irq\n");
+		return ret;
+	}
+
+	/* Encoder */
+
+	drm_encoder_helper_add(encoder, &meson_venc_hdmi_encoder_helper_funcs);
+
+	ret = drm_encoder_init(drm, encoder, &meson_venc_hdmi_encoder_funcs,
+			       DRM_MODE_ENCODER_TMDS, "meson_hdmi");
+	if (ret) {
+		dev_err(priv->dev, "Failed to init HDMI encoder\n");
+		return ret;
+	}
+
+	encoder->possible_crtcs = BIT(0);
+
+	DRM_DEBUG_DRIVER("encoder initialized\n");
+
+	/* Enable clocks */
+	regmap_update_bits(priv->hhi, HHI_HDMI_CLK_CNTL, 0xffff, 0x100);
+
+	/* Bring HDMITX MEM output of power down */
+	regmap_update_bits(priv->hhi, HHI_MEM_PD_REG0, 0xff << 8, 0);
+
+	/* Reset HDMITX APB & TX & PHY */
+	reset_control_reset(meson_dw_hdmi->hdmitx_apb);
+	reset_control_reset(meson_dw_hdmi->hdmitx_ctrl);
+	reset_control_reset(meson_dw_hdmi->hdmitx_phy);
+
+	/* Enable APB3 fail on error */
+	writel_bits_relaxed(BIT(15), BIT(15),
+			    meson_dw_hdmi->hdmitx + HDMITX_TOP_CTRL_REG);
+	writel_bits_relaxed(BIT(15), BIT(15),
+			    meson_dw_hdmi->hdmitx + HDMITX_DWC_CTRL_REG);
+
+	/* Bring out of reset */
+	dw_hdmi_top_write(meson_dw_hdmi, HDMITX_TOP_SW_RESET,  0);
+
+	msleep(20);
+
+	dw_hdmi_top_write(meson_dw_hdmi, HDMITX_TOP_CLK_CNTL, 0xff);
+
+	/* Enable HDMI-TX Interrupt */
+	dw_hdmi_top_write(meson_dw_hdmi, HDMITX_TOP_INTR_STAT_CLR,
+			  HDMITX_TOP_INTR_CORE);
+
+	dw_hdmi_top_write(meson_dw_hdmi, HDMITX_TOP_INTR_MASKN,
+			  HDMITX_TOP_INTR_CORE);
+
+	/* Bridge / Connector */
+
+	dw_plat_data->mode_valid = dw_hdmi_mode_valid;
+	dw_plat_data->phy_ops = &meson_dw_hdmi_phy_ops;
+	dw_plat_data->phy_name = "meson_dw_hdmi_phy";
+	dw_plat_data->phy_data = meson_dw_hdmi;
+	dw_plat_data->input_bus_format = MEDIA_BUS_FMT_YUV8_1X24;
+	dw_plat_data->input_bus_encoding = V4L2_YCBCR_ENC_709;
+
+	ret = dw_hdmi_bind(pdev, encoder, &meson_dw_hdmi->dw_plat_data);
+	if (ret)
+		return ret;
+
+	DRM_DEBUG_DRIVER("HDMI controller initialized\n");
+
+	return 0;
+}
+
+static void meson_dw_hdmi_unbind(struct device *dev, struct device *master,
+				   void *data)
+{
+	dw_hdmi_unbind(dev);
+}
+
+static const struct component_ops meson_dw_hdmi_ops = {
+	.bind	= meson_dw_hdmi_bind,
+	.unbind	= meson_dw_hdmi_unbind,
+};
+
+static int meson_dw_hdmi_probe(struct platform_device *pdev)
+{
+	return component_add(&pdev->dev, &meson_dw_hdmi_ops);
+}
+
+static int meson_dw_hdmi_remove(struct platform_device *pdev)
+{
+	component_del(&pdev->dev, &meson_dw_hdmi_ops);
+
+	return 0;
+}
+
+static const struct of_device_id meson_dw_hdmi_of_table[] = {
+	{ .compatible = "amlogic,meson-gxbb-dw-hdmi" },
+	{ .compatible = "amlogic,meson-gxl-dw-hdmi" },
+	{ .compatible = "amlogic,meson-gxm-dw-hdmi" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, meson_dw_hdmi_of_table);
+
+static struct platform_driver meson_dw_hdmi_platform_driver = {
+	.probe		= meson_dw_hdmi_probe,
+	.remove		= meson_dw_hdmi_remove,
+	.driver		= {
+		.name		= DRIVER_NAME,
+		.of_match_table	= meson_dw_hdmi_of_table,
+	},
+};
+module_platform_driver(meson_dw_hdmi_platform_driver);
+
+MODULE_AUTHOR("Neil Armstrong <[e-mail]>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");

drivers/gpu/drm/meson/meson_dw_hdmi.h

···
+/*
+ * Copyright (C) 2016 BayLibre, SAS
+ * Author: Neil Armstrong <[e-mail]>
+ * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __MESON_DW_HDMI_H
+#define __MESON_DW_HDMI_H
+
+/*
+ * Bit 7 RW Reserved. Default 1.
+ * Bit 6 RW Reserved. Default 1.
+ * Bit 5 RW Reserved. Default 1.
+ * Bit 4 RW sw_reset_phyif: PHY interface. 1=Apply reset; 0=Release from reset.
+ *     Default 1.
+ * Bit 3 RW sw_reset_intr: interrupt module. 1=Apply reset;
+ *     0=Release from reset.
+ *     Default 1.
+ * Bit 2 RW sw_reset_mem: KSV/REVOC mem. 1=Apply reset; 0=Release from reset.
+ *     Default 1.
+ * Bit 1 RW sw_reset_rnd: random number interface to HDCP. 1=Apply reset;
+ *     0=Release from reset. Default 1.
+ * Bit 0 RW sw_reset_core: connects to IP's ~irstz. 1=Apply reset;
+ *     0=Release from reset. Default 1.
+ */
+#define HDMITX_TOP_SW_RESET                     (0x000)
+
+/*
+ * Bit 12 RW i2s_ws_inv:1=Invert i2s_ws; 0=No invert. Default 0.
+ * Bit 11 RW i2s_clk_inv: 1=Invert i2s_clk; 0=No invert. Default 0.
+ * Bit 10 RW spdif_clk_inv: 1=Invert spdif_clk; 0=No invert. Default 0.
+ * Bit 9 RW tmds_clk_inv: 1=Invert tmds_clk; 0=No invert. Default 0.
+ * Bit 8 RW pixel_clk_inv: 1=Invert pixel_clk; 0=No invert. Default 0.
+ * Bit 4 RW cec_clk_en: 1=enable cec_clk; 0=disable. Default 0.
+ * Bit 3 RW i2s_clk_en: 1=enable i2s_clk; 0=disable. Default 0.
+ * Bit 2 RW spdif_clk_en: 1=enable spdif_clk; 0=disable. Default 0.
+ * Bit 1 RW tmds_clk_en: 1=enable tmds_clk;  0=disable. Default 0.
+ * Bit 0 RW pixel_clk_en: 1=enable pixel_clk; 0=disable. Default 0.
+ */
+#define HDMITX_TOP_CLK_CNTL                     (0x001)
+
+/*
+ * Bit 11: 0 RW hpd_valid_width: filter out width <= M*1024.    Default 0.
+ * Bit 15:12 RW hpd_glitch_width: filter out glitch <= N.       Default 0.
+ */
+#define HDMITX_TOP_HPD_FILTER                   (0x002)
+
+/*
+ * intr_maskn: MASK_N, one bit per interrupt source.
+ *     1=Enable interrupt source; 0=Disable interrupt source. Default 0.
+ * [  4] hdcp22_rndnum_err
+ * [  3] nonce_rfrsh_rise
+ * [  2] hpd_fall_intr
+ * [  1] hpd_rise_intr
+ * [  0] core_intr
+ */
+#define HDMITX_TOP_INTR_MASKN                   (0x003)
+
+/*
+ * Bit 30: 0 RW intr_stat: For each bit, write 1 to manually set the interrupt
+ *     bit, read back the interrupt status.
+ * Bit    31 R  IP interrupt status
+ * Bit     2 RW hpd_fall
+ * Bit     1 RW hpd_rise
+ * Bit     0 RW IP interrupt
+ */
+#define HDMITX_TOP_INTR_STAT                    (0x004)
+
+/*
+ * [4]	  hdcp22_rndnum_err
+ * [3]	  nonce_rfrsh_rise
+ * [2]	  hpd_fall
+ * [1]	  hpd_rise
+ * [0]	  core_intr_rise
+ */
+#define HDMITX_TOP_INTR_STAT_CLR                (0x005)
+
+#define HDMITX_TOP_INTR_CORE		BIT(0)
+#define HDMITX_TOP_INTR_HPD_RISE	BIT(1)
+#define HDMITX_TOP_INTR_HPD_FALL	BIT(2)
+
+/* Bit 14:12 RW tmds_sel: 3'b000=Output zero; 3'b001=Output normal TMDS data;
+ *     3'b010=Output PRBS data; 3'b100=Output shift pattern. Default 0.
+ * Bit 11: 9 RW shift_pttn_repeat: 0=New pattern every clk cycle; 1=New pattern
+ *     every 2 clk cycles; ...; 7=New pattern every 8 clk cycles. Default 0.
+ * Bit 8 RW shift_pttn_en: 1= Enable shift pattern generator; 0=Disable.
+ *     Default 0.
+ * Bit 4: 3 RW prbs_pttn_mode: 0=PRBS11; 1=PRBS15; 2=PRBS7; 3=PRBS31. Default 0.
+ * Bit 2: 1 RW prbs_pttn_width: 0=idle; 1=output 8-bit pattern;
+ *     2=Output 1-bit pattern; 3=output 10-bit pattern. Default 0.
+ * Bit 0 RW prbs_pttn_en: 1=Enable PRBS generator; 0=Disable. Default 0.
+ */
+#define HDMITX_TOP_BIST_CNTL                    (0x006)
+
+/* Bit 29:20 RW shift_pttn_data[59:50]. Default 0. */
+/* Bit 19:10 RW shift_pttn_data[69:60]. Default 0. */
+/* Bit  9: 0 RW shift_pttn_data[79:70]. Default 0. */
+#define HDMITX_TOP_SHIFT_PTTN_012               (0x007)
+
+/* Bit 29:20 RW shift_pttn_data[29:20]. Default 0. */
+/* Bit 19:10 RW shift_pttn_data[39:30]. Default 0. */
+/* Bit  9: 0 RW shift_pttn_data[49:40]. Default 0. */
+#define HDMITX_TOP_SHIFT_PTTN_345               (0x008)
+
+/* Bit 19:10 RW shift_pttn_data[ 9: 0]. Default 0. */
+/* Bit  9: 0 RW shift_pttn_data[19:10]. Default 0. */
+#define HDMITX_TOP_SHIFT_PTTN_67                (0x009)
+
+/* Bit 25:16 RW tmds_clk_pttn[19:10]. Default 0. */
+/* Bit  9: 0 RW tmds_clk_pttn[ 9: 0]. Default 0. */
+#define HDMITX_TOP_TMDS_CLK_PTTN_01             (0x00A)
+
+/* Bit 25:16 RW tmds_clk_pttn[39:30]. Default 0. */
+/* Bit  9: 0 RW tmds_clk_pttn[29:20]. Default 0. */
+#define HDMITX_TOP_TMDS_CLK_PTTN_23             (0x00B)
+
+/* Bit 1 RW shift_tmds_clk_pttn:1=Enable shifting clk pattern,
+ * used when TMDS CLK rate = TMDS character rate /4. Default 0.
+ * Bit 0 R  Reserved. Default 0.
+ * [	1] shift_tmds_clk_pttn
+ * [	0] load_tmds_clk_pttn
+ */
+#define HDMITX_TOP_TMDS_CLK_PTTN_CNTL           (0x00C)
+
+/* Bit 0 RW revocmem_wr_fail: Read back 1 to indicate Host write REVOC MEM
+ * failure, write 1 to clear the failure flag.  Default 0.
+ */
+#define HDMITX_TOP_REVOCMEM_STAT                (0x00D)
+
+/* Bit     0 R  filtered HPD status. */
+#define HDMITX_TOP_STAT0                        (0x00E)
+
+#endif /* __MESON_DW_HDMI_H */