drm/mediatek: Add HDMI support

This patch adds drivers for the HDMI bridge connected to the DPI0
display subsystem function block, for the HDMI DDC block, and for
the HDMI PHY to support HDMI output.
This includes an interface to the generic hdmi-codec driver to start
or stop audio playback and to retrieve ELD (EDID like data) to limit the
supported audio formats to the HDMI sink capabilities.
Signed-off-by: Jie Qiu <jie.qiu@mediatek.com>
Signed-off-by: Junzhi Zhao <junzhi.zhao@mediatek.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/mediatek/Kconfig

@@ -14,3 +14,11 @@ config DRM_MEDIATEK
 	  The module will be called mediatek-drm
 	  This driver provides kernel mode setting and
 	  buffer management to userspace.
+
+config DRM_MEDIATEK_HDMI
+	tristate "DRM HDMI Support for Mediatek SoCs"
+	depends on DRM_MEDIATEK
+	select SND_SOC_HDMI_CODEC if SND_SOC
+	select GENERIC_PHY
+	help
+	  DRM/KMS HDMI driver for Mediatek SoCs

drivers/gpu/drm/mediatek/Makefile

@@ -12,3 +12,10 @@ mediatek-drm-y := mtk_disp_ovl.o \
 		  mtk_dpi.o
 
 obj-$(CONFIG_DRM_MEDIATEK) += mediatek-drm.o
+
+mediatek-drm-hdmi-objs := mtk_cec.o \
+			  mtk_hdmi.o \
+			  mtk_hdmi_ddc.o \
+			  mtk_mt8173_hdmi_phy.o
+
+obj-$(CONFIG_DRM_MEDIATEK_HDMI) += mediatek-drm-hdmi.o

drivers/gpu/drm/mediatek/mtk_cec.c

+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ * Author: Jie Qiu <jie.qiu@mediatek.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 <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#include "mtk_cec.h"
+
+#define TR_CONFIG		0x00
+#define CLEAR_CEC_IRQ			BIT(15)
+
+#define CEC_CKGEN		0x04
+#define CEC_32K_PDN			BIT(19)
+#define PDN				BIT(16)
+
+#define RX_EVENT		0x54
+#define HDMI_PORD			BIT(25)
+#define HDMI_HTPLG			BIT(24)
+#define HDMI_PORD_INT_EN		BIT(9)
+#define HDMI_HTPLG_INT_EN		BIT(8)
+
+#define RX_GEN_WD		0x58
+#define HDMI_PORD_INT_32K_STATUS	BIT(26)
+#define RX_RISC_INT_32K_STATUS		BIT(25)
+#define HDMI_HTPLG_INT_32K_STATUS	BIT(24)
+#define HDMI_PORD_INT_32K_CLR		BIT(18)
+#define RX_INT_32K_CLR			BIT(17)
+#define HDMI_HTPLG_INT_32K_CLR		BIT(16)
+#define HDMI_PORD_INT_32K_STA_MASK	BIT(10)
+#define RX_RISC_INT_32K_STA_MASK	BIT(9)
+#define HDMI_HTPLG_INT_32K_STA_MASK	BIT(8)
+#define HDMI_PORD_INT_32K_EN		BIT(2)
+#define RX_INT_32K_EN			BIT(1)
+#define HDMI_HTPLG_INT_32K_EN		BIT(0)
+
+#define NORMAL_INT_CTRL		0x5C
+#define HDMI_HTPLG_INT_STA		BIT(0)
+#define HDMI_PORD_INT_STA		BIT(1)
+#define HDMI_HTPLG_INT_CLR		BIT(16)
+#define HDMI_PORD_INT_CLR		BIT(17)
+#define HDMI_FULL_INT_CLR		BIT(20)
+
+struct mtk_cec {
+	void __iomem *regs;
+	struct clk *clk;
+	int irq;
+	bool hpd;
+	void (*hpd_event)(bool hpd, struct device *dev);
+	struct device *hdmi_dev;
+	spinlock_t lock;
+};
+
+static void mtk_cec_clear_bits(struct mtk_cec *cec, unsigned int offset,
+			       unsigned int bits)
+{
+	void __iomem *reg = cec->regs + offset;
+	u32 tmp;
+
+	tmp = readl(reg);
+	tmp &= ~bits;
+	writel(tmp, reg);
+}
+
+static void mtk_cec_set_bits(struct mtk_cec *cec, unsigned int offset,
+			     unsigned int bits)
+{
+	void __iomem *reg = cec->regs + offset;
+	u32 tmp;
+
+	tmp = readl(reg);
+	tmp |= bits;
+	writel(tmp, reg);
+}
+
+static void mtk_cec_mask(struct mtk_cec *cec, unsigned int offset,
+			 unsigned int val, unsigned int mask)
+{
+	u32 tmp = readl(cec->regs + offset) & ~mask;
+
+	tmp |= val & mask;
+	writel(val, cec->regs + offset);
+}
+
+void mtk_cec_set_hpd_event(struct device *dev,
+			   void (*hpd_event)(bool hpd, struct device *dev),
+			   struct device *hdmi_dev)
+{
+	struct mtk_cec *cec = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&cec->lock, flags);
+	cec->hdmi_dev = hdmi_dev;
+	cec->hpd_event = hpd_event;
+	spin_unlock_irqrestore(&cec->lock, flags);
+}
+
+bool mtk_cec_hpd_high(struct device *dev)
+{
+	struct mtk_cec *cec = dev_get_drvdata(dev);
+	unsigned int status;
+
+	status = readl(cec->regs + RX_EVENT);
+
+	return (status & (HDMI_PORD | HDMI_HTPLG)) == (HDMI_PORD | HDMI_HTPLG);
+}
+
+static void mtk_cec_htplg_irq_init(struct mtk_cec *cec)
+{
+	mtk_cec_mask(cec, CEC_CKGEN, 0 | CEC_32K_PDN, PDN | CEC_32K_PDN);
+	mtk_cec_set_bits(cec, RX_GEN_WD, HDMI_PORD_INT_32K_CLR |
+			 RX_INT_32K_CLR | HDMI_HTPLG_INT_32K_CLR);
+	mtk_cec_mask(cec, RX_GEN_WD, 0, HDMI_PORD_INT_32K_CLR | RX_INT_32K_CLR |
+		     HDMI_HTPLG_INT_32K_CLR | HDMI_PORD_INT_32K_EN |
+		     RX_INT_32K_EN | HDMI_HTPLG_INT_32K_EN);
+}
+
+static void mtk_cec_htplg_irq_enable(struct mtk_cec *cec)
+{
+	mtk_cec_set_bits(cec, RX_EVENT, HDMI_PORD_INT_EN | HDMI_HTPLG_INT_EN);
+}
+
+static void mtk_cec_htplg_irq_disable(struct mtk_cec *cec)
+{
+	mtk_cec_clear_bits(cec, RX_EVENT, HDMI_PORD_INT_EN | HDMI_HTPLG_INT_EN);
+}
+
+static void mtk_cec_clear_htplg_irq(struct mtk_cec *cec)
+{
+	mtk_cec_set_bits(cec, TR_CONFIG, CLEAR_CEC_IRQ);
+	mtk_cec_set_bits(cec, NORMAL_INT_CTRL, HDMI_HTPLG_INT_CLR |
+			 HDMI_PORD_INT_CLR | HDMI_FULL_INT_CLR);
+	mtk_cec_set_bits(cec, RX_GEN_WD, HDMI_PORD_INT_32K_CLR |
+			 RX_INT_32K_CLR | HDMI_HTPLG_INT_32K_CLR);
+	usleep_range(5, 10);
+	mtk_cec_clear_bits(cec, NORMAL_INT_CTRL, HDMI_HTPLG_INT_CLR |
+			   HDMI_PORD_INT_CLR | HDMI_FULL_INT_CLR);
+	mtk_cec_clear_bits(cec, TR_CONFIG, CLEAR_CEC_IRQ);
+	mtk_cec_clear_bits(cec, RX_GEN_WD, HDMI_PORD_INT_32K_CLR |
+			   RX_INT_32K_CLR | HDMI_HTPLG_INT_32K_CLR);
+}
+
+static void mtk_cec_hpd_event(struct mtk_cec *cec, bool hpd)
+{
+	void (*hpd_event)(bool hpd, struct device *dev);
+	struct device *hdmi_dev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cec->lock, flags);
+	hpd_event = cec->hpd_event;
+	hdmi_dev = cec->hdmi_dev;
+	spin_unlock_irqrestore(&cec->lock, flags);
+
+	if (hpd_event)
+		hpd_event(hpd, hdmi_dev);
+}
+
+static irqreturn_t mtk_cec_htplg_isr_thread(int irq, void *arg)
+{
+	struct device *dev = arg;
+	struct mtk_cec *cec = dev_get_drvdata(dev);
+	bool hpd;
+
+	mtk_cec_clear_htplg_irq(cec);
+	hpd = mtk_cec_hpd_high(dev);
+
+	if (cec->hpd != hpd) {
+		dev_dbg(dev, "hotplug event! cur hpd = %d, hpd = %d\n",
+			cec->hpd, hpd);
+		cec->hpd = hpd;
+		mtk_cec_hpd_event(cec, hpd);
+	}
+	return IRQ_HANDLED;
+}
+
+static int mtk_cec_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_cec *cec;
+	struct resource *res;
+	int ret;
+
+	cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL);
+	if (!cec)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, cec);
+	spin_lock_init(&cec->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	cec->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(cec->regs)) {
+		ret = PTR_ERR(cec->regs);
+		dev_err(dev, "Failed to ioremap cec: %d\n", ret);
+		return ret;
+	}
+
+	cec->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(cec->clk)) {
+		ret = PTR_ERR(cec->clk);
+		dev_err(dev, "Failed to get cec clock: %d\n", ret);
+		return ret;
+	}
+
+	cec->irq = platform_get_irq(pdev, 0);
+	if (cec->irq < 0) {
+		dev_err(dev, "Failed to get cec irq: %d\n", cec->irq);
+		return cec->irq;
+	}
+
+	ret = devm_request_threaded_irq(dev, cec->irq, NULL,
+					mtk_cec_htplg_isr_thread,
+					IRQF_SHARED | IRQF_TRIGGER_LOW |
+					IRQF_ONESHOT, "hdmi hpd", dev);
+	if (ret) {
+		dev_err(dev, "Failed to register cec irq: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(cec->clk);
+	if (ret) {
+		dev_err(dev, "Failed to enable cec clock: %d\n", ret);
+		return ret;
+	}
+
+	mtk_cec_htplg_irq_init(cec);
+	mtk_cec_htplg_irq_enable(cec);
+
+	return 0;
+}
+
+static int mtk_cec_remove(struct platform_device *pdev)
+{
+	struct mtk_cec *cec = platform_get_drvdata(pdev);
+
+	mtk_cec_htplg_irq_disable(cec);
+	clk_disable_unprepare(cec->clk);
+	return 0;
+}
+
+static const struct of_device_id mtk_cec_of_ids[] = {
+	{ .compatible = "mediatek,mt8173-cec", },
+	{}
+};
+
+struct platform_driver mtk_cec_driver = {
+	.probe = mtk_cec_probe,
+	.remove = mtk_cec_remove,
+	.driver = {
+		.name = "mediatek-cec",
+		.of_match_table = mtk_cec_of_ids,
+	},
+};

drivers/gpu/drm/mediatek/mtk_cec.h

+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ * Author: Jie Qiu <jie.qiu@mediatek.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 _MTK_CEC_H
+#define _MTK_CEC_H
+
+#include <linux/types.h>
+
+struct device;
+
+void mtk_cec_set_hpd_event(struct device *dev,
+			   void (*hotplug_event)(bool hpd, struct device *dev),
+			   struct device *hdmi_dev);
+bool mtk_cec_hpd_high(struct device *dev);
+
+#endif /* _MTK_CEC_H */

drivers/gpu/drm/mediatek/mtk_hdmi.h

+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ * Author: Jie Qiu <jie.qiu@mediatek.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 _MTK_HDMI_CTRL_H
+#define _MTK_HDMI_CTRL_H
+
+struct platform_driver;
+
+extern struct platform_driver mtk_cec_driver;
+extern struct platform_driver mtk_hdmi_ddc_driver;
+extern struct platform_driver mtk_hdmi_phy_driver;
+
+#endif /* _MTK_HDMI_CTRL_H */

drivers/gpu/drm/mediatek/mtk_hdmi_ddc.c

+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ * Author: Jie Qiu <jie.qiu@mediatek.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 <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/time.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+
+#define SIF1_CLOK		(288)
+#define DDC_DDCMCTL0		(0x0)
+#define DDCM_ODRAIN			BIT(31)
+#define DDCM_CLK_DIV_OFFSET		(16)
+#define DDCM_CLK_DIV_MASK		(0xfff << 16)
+#define DDCM_CS_STATUS			BIT(4)
+#define DDCM_SCL_STATE			BIT(3)
+#define DDCM_SDA_STATE			BIT(2)
+#define DDCM_SM0EN			BIT(1)
+#define DDCM_SCL_STRECH			BIT(0)
+#define DDC_DDCMCTL1		(0x4)
+#define DDCM_ACK_OFFSET			(16)
+#define DDCM_ACK_MASK			(0xff << 16)
+#define DDCM_PGLEN_OFFSET		(8)
+#define DDCM_PGLEN_MASK			(0x7 << 8)
+#define DDCM_SIF_MODE_OFFSET		(4)
+#define DDCM_SIF_MODE_MASK		(0x7 << 4)
+#define DDCM_START			(0x1)
+#define DDCM_WRITE_DATA			(0x2)
+#define DDCM_STOP			(0x3)
+#define DDCM_READ_DATA_NO_ACK		(0x4)
+#define DDCM_READ_DATA_ACK		(0x5)
+#define DDCM_TRI			BIT(0)
+#define DDC_DDCMD0		(0x8)
+#define DDCM_DATA3			(0xff << 24)
+#define DDCM_DATA2			(0xff << 16)
+#define DDCM_DATA1			(0xff << 8)
+#define DDCM_DATA0			(0xff << 0)
+#define DDC_DDCMD1		(0xc)
+#define DDCM_DATA7			(0xff << 24)
+#define DDCM_DATA6			(0xff << 16)
+#define DDCM_DATA5			(0xff << 8)
+#define DDCM_DATA4			(0xff << 0)
+
+struct mtk_hdmi_ddc {
+	struct i2c_adapter adap;
+	struct clk *clk;
+	void __iomem *regs;
+};
+
+static inline void sif_set_bit(struct mtk_hdmi_ddc *ddc, unsigned int offset,
+			       unsigned int val)
+{
+	writel(readl(ddc->regs + offset) | val, ddc->regs + offset);
+}
+
+static inline void sif_clr_bit(struct mtk_hdmi_ddc *ddc, unsigned int offset,
+			       unsigned int val)
+{
+	writel(readl(ddc->regs + offset) & ~val, ddc->regs + offset);
+}
+
+static inline bool sif_bit_is_set(struct mtk_hdmi_ddc *ddc, unsigned int offset,
+				  unsigned int val)
+{
+	return (readl(ddc->regs + offset) & val) == val;
+}
+
+static inline void sif_write_mask(struct mtk_hdmi_ddc *ddc, unsigned int offset,
+				  unsigned int mask, unsigned int shift,
+				  unsigned int val)
+{
+	unsigned int tmp;
+
+	tmp = readl(ddc->regs + offset);
+	tmp &= ~mask;
+	tmp |= (val << shift) & mask;
+	writel(tmp, ddc->regs + offset);
+}
+
+static inline unsigned int sif_read_mask(struct mtk_hdmi_ddc *ddc,
+					 unsigned int offset, unsigned int mask,
+					 unsigned int shift)
+{
+	return (readl(ddc->regs + offset) & mask) >> shift;
+}
+
+static void ddcm_trigger_mode(struct mtk_hdmi_ddc *ddc, int mode)
+{
+	u32 val;
+
+	sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_SIF_MODE_MASK,
+		       DDCM_SIF_MODE_OFFSET, mode);
+	sif_set_bit(ddc, DDC_DDCMCTL1, DDCM_TRI);
+	readl_poll_timeout(ddc->regs + DDC_DDCMCTL1, val,
+			   (val & DDCM_TRI) != DDCM_TRI, 4, 20000);
+}
+
+static int mtk_hdmi_ddc_read_msg(struct mtk_hdmi_ddc *ddc, struct i2c_msg *msg)
+{
+	struct device *dev = ddc->adap.dev.parent;
+	u32 remain_count, ack_count, ack_final, read_count, temp_count;
+	u32 index = 0;
+	u32 ack;
+	int i;
+
+	ddcm_trigger_mode(ddc, DDCM_START);
+	sif_write_mask(ddc, DDC_DDCMD0, 0xff, 0, (msg->addr << 1) | 0x01);
+	sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_PGLEN_MASK, DDCM_PGLEN_OFFSET,
+		       0x00);
+	ddcm_trigger_mode(ddc, DDCM_WRITE_DATA);
+	ack = sif_read_mask(ddc, DDC_DDCMCTL1, DDCM_ACK_MASK, DDCM_ACK_OFFSET);
+	dev_dbg(dev, "ack = 0x%x\n", ack);
+	if (ack != 0x01) {
+		dev_err(dev, "i2c ack err!\n");
+		return -ENXIO;
+	}
+
+	remain_count = msg->len;
+	ack_count = (msg->len - 1) / 8;
+	ack_final = 0;
+
+	while (remain_count > 0) {
+		if (ack_count > 0) {
+			read_count = 8;
+			ack_final = 0;
+			ack_count--;
+		} else {
+			read_count = remain_count;
+			ack_final = 1;
+		}
+
+		sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_PGLEN_MASK,
+			       DDCM_PGLEN_OFFSET, read_count - 1);
+		ddcm_trigger_mode(ddc, (ack_final == 1) ?
+				  DDCM_READ_DATA_NO_ACK :
+				  DDCM_READ_DATA_ACK);
+
+		ack = sif_read_mask(ddc, DDC_DDCMCTL1, DDCM_ACK_MASK,
+				    DDCM_ACK_OFFSET);
+		temp_count = 0;
+		while (((ack & (1 << temp_count)) != 0) && (temp_count < 8))
+			temp_count++;
+		if (((ack_final == 1) && (temp_count != (read_count - 1))) ||
+		    ((ack_final == 0) && (temp_count != read_count))) {
+			dev_err(dev, "Address NACK! ACK(0x%x)\n", ack);
+			break;
+		}
+
+		for (i = read_count; i >= 1; i--) {
+			int shift;
+			int offset;
+
+			if (i > 4) {
+				offset = DDC_DDCMD1;
+				shift = (i - 5) * 8;
+			} else {
+				offset = DDC_DDCMD0;
+				shift = (i - 1) * 8;
+			}
+
+			msg->buf[index + i - 1] = sif_read_mask(ddc, offset,
+								0xff << shift,
+								shift);
+		}
+
+		remain_count -= read_count;
+		index += read_count;
+	}
+
+	return 0;
+}
+
+static int mtk_hdmi_ddc_write_msg(struct mtk_hdmi_ddc *ddc, struct i2c_msg *msg)
+{
+	struct device *dev = ddc->adap.dev.parent;
+	u32 ack;
+
+	ddcm_trigger_mode(ddc, DDCM_START);
+	sif_write_mask(ddc, DDC_DDCMD0, DDCM_DATA0, 0, msg->addr << 1);
+	sif_write_mask(ddc, DDC_DDCMD0, DDCM_DATA1, 8, msg->buf[0]);
+	sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_PGLEN_MASK, DDCM_PGLEN_OFFSET,
+		       0x1);
+	ddcm_trigger_mode(ddc, DDCM_WRITE_DATA);
+
+	ack = sif_read_mask(ddc, DDC_DDCMCTL1, DDCM_ACK_MASK, DDCM_ACK_OFFSET);
+	dev_dbg(dev, "ack = %d\n", ack);
+
+	if (ack != 0x03) {
+		dev_err(dev, "i2c ack err!\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int mtk_hdmi_ddc_xfer(struct i2c_adapter *adapter,
+			     struct i2c_msg *msgs, int num)
+{
+	struct mtk_hdmi_ddc *ddc = adapter->algo_data;
+	struct device *dev = adapter->dev.parent;
+	int ret;
+	int i;
+
+	if (!ddc) {
+		dev_err(dev, "invalid arguments\n");
+		return -EINVAL;
+	}
+
+	sif_set_bit(ddc, DDC_DDCMCTL0, DDCM_SCL_STRECH);
+	sif_set_bit(ddc, DDC_DDCMCTL0, DDCM_SM0EN);
+	sif_clr_bit(ddc, DDC_DDCMCTL0, DDCM_ODRAIN);
+
+	if (sif_bit_is_set(ddc, DDC_DDCMCTL1, DDCM_TRI)) {
+		dev_err(dev, "ddc line is busy!\n");
+		return -EBUSY;
+	}
+
+	sif_write_mask(ddc, DDC_DDCMCTL0, DDCM_CLK_DIV_MASK,
+		       DDCM_CLK_DIV_OFFSET, SIF1_CLOK);
+
+	for (i = 0; i < num; i++) {
+		struct i2c_msg *msg = &msgs[i];
+
+		dev_dbg(dev, "i2c msg, adr:0x%x, flags:%d, len :0x%x\n",
+			msg->addr, msg->flags, msg->len);
+
+		if (msg->flags & I2C_M_RD)
+			ret = mtk_hdmi_ddc_read_msg(ddc, msg);
+		else
+			ret = mtk_hdmi_ddc_write_msg(ddc, msg);
+		if (ret < 0)
+			goto xfer_end;
+	}
+
+	ddcm_trigger_mode(ddc, DDCM_STOP);
+
+	return i;
+
+xfer_end:
+	ddcm_trigger_mode(ddc, DDCM_STOP);
+	dev_err(dev, "ddc failed!\n");
+	return ret;
+}
+
+static u32 mtk_hdmi_ddc_func(struct i2c_adapter *adapter)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm mtk_hdmi_ddc_algorithm = {
+	.master_xfer = mtk_hdmi_ddc_xfer,
+	.functionality = mtk_hdmi_ddc_func,
+};
+
+static int mtk_hdmi_ddc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_hdmi_ddc *ddc;
+	struct resource *mem;
+	int ret;
+
+	ddc = devm_kzalloc(dev, sizeof(struct mtk_hdmi_ddc), GFP_KERNEL);
+	if (!ddc)
+		return -ENOMEM;
+
+	ddc->clk = devm_clk_get(dev, "ddc-i2c");
+	if (IS_ERR(ddc->clk)) {
+		dev_err(dev, "get ddc_clk failed: %p ,\n", ddc->clk);
+		return PTR_ERR(ddc->clk);
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ddc->regs = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(ddc->regs))
+		return PTR_ERR(ddc->regs);
+
+	ret = clk_prepare_enable(ddc->clk);
+	if (ret) {
+		dev_err(dev, "enable ddc clk failed!\n");
+		return ret;
+	}
+
+	strlcpy(ddc->adap.name, "mediatek-hdmi-ddc", sizeof(ddc->adap.name));
+	ddc->adap.owner = THIS_MODULE;
+	ddc->adap.class = I2C_CLASS_DDC;
+	ddc->adap.algo = &mtk_hdmi_ddc_algorithm;
+	ddc->adap.retries = 3;
+	ddc->adap.dev.of_node = dev->of_node;
+	ddc->adap.algo_data = ddc;
+	ddc->adap.dev.parent = &pdev->dev;
+
+	ret = i2c_add_adapter(&ddc->adap);
+	if (ret < 0) {
+		dev_err(dev, "failed to add bus to i2c core\n");
+		goto err_clk_disable;
+	}
+
+	platform_set_drvdata(pdev, ddc);
+
+	dev_dbg(dev, "ddc->adap: %p\n", &ddc->adap);
+	dev_dbg(dev, "ddc->clk: %p\n", ddc->clk);
+	dev_dbg(dev, "physical adr: %pa, end: %pa\n", &mem->start,
+		&mem->end);
+
+	return 0;
+
+err_clk_disable:
+	clk_disable_unprepare(ddc->clk);
+	return ret;
+}
+
+static int mtk_hdmi_ddc_remove(struct platform_device *pdev)
+{
+	struct mtk_hdmi_ddc *ddc = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&ddc->adap);
+	clk_disable_unprepare(ddc->clk);
+
+	return 0;
+}
+
+static const struct of_device_id mtk_hdmi_ddc_match[] = {
+	{ .compatible = "mediatek,mt8173-hdmi-ddc", },
+	{},
+};
+
+struct platform_driver mtk_hdmi_ddc_driver = {
+	.probe = mtk_hdmi_ddc_probe,
+	.remove = mtk_hdmi_ddc_remove,
+	.driver = {
+		.name = "mediatek-hdmi-ddc",
+		.of_match_table = mtk_hdmi_ddc_match,
+	},
+};
+
+MODULE_AUTHOR("Jie Qiu <jie.qiu@mediatek.com>");
+MODULE_DESCRIPTION("MediaTek HDMI DDC Driver");
+MODULE_LICENSE("GPL v2");

drivers/gpu/drm/mediatek/mtk_hdmi_regs.h

+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ * Author: Jie Qiu <jie.qiu@mediatek.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 _MTK_HDMI_REGS_H
+#define _MTK_HDMI_REGS_H
+
+#define GRL_INT_MASK		0x18
+#define GRL_IFM_PORT		0x188
+#define GRL_CH_SWAP		0x198
+#define LR_SWAP				BIT(0)
+#define LFE_CC_SWAP			BIT(1)
+#define LSRS_SWAP			BIT(2)
+#define RLS_RRS_SWAP			BIT(3)
+#define LR_STATUS_SWAP			BIT(4)
+#define GRL_I2S_C_STA0		0x140
+#define GRL_I2S_C_STA1		0x144
+#define GRL_I2S_C_STA2		0x148
+#define GRL_I2S_C_STA3		0x14C
+#define GRL_I2S_C_STA4		0x150
+#define GRL_I2S_UV		0x154
+#define I2S_UV_V			BIT(0)
+#define I2S_UV_U			BIT(1)
+#define I2S_UV_CH_EN_MASK		0x3c
+#define I2S_UV_CH_EN(x)			BIT((x) + 2)
+#define I2S_UV_TMDS_DEBUG		BIT(6)
+#define I2S_UV_NORMAL_INFO_INV		BIT(7)
+#define GRL_ACP_ISRC_CTRL	0x158
+#define VS_EN				BIT(0)
+#define ACP_EN				BIT(1)
+#define ISRC1_EN			BIT(2)
+#define ISRC2_EN			BIT(3)
+#define GAMUT_EN			BIT(4)
+#define GRL_CTS_CTRL		0x160
+#define CTS_CTRL_SOFT			BIT(0)
+#define GRL_INT			0x14
+#define INT_MDI				BIT(0)
+#define INT_HDCP			BIT(1)
+#define INT_FIFO_O			BIT(2)
+#define INT_FIFO_U			BIT(3)
+#define INT_IFM_ERR			BIT(4)
+#define INT_INF_DONE			BIT(5)
+#define INT_NCTS_DONE			BIT(6)
+#define INT_CTRL_PKT_DONE		BIT(7)
+#define GRL_INT_MASK		0x18
+#define GRL_CTRL		0x1C
+#define CTRL_GEN_EN			BIT(2)
+#define CTRL_SPD_EN			BIT(3)
+#define CTRL_MPEG_EN			BIT(4)
+#define CTRL_AUDIO_EN			BIT(5)
+#define CTRL_AVI_EN			BIT(6)
+#define CTRL_AVMUTE			BIT(7)
+#define	GRL_STATUS		0x20
+#define STATUS_HTPLG			BIT(0)
+#define STATUS_PORD			BIT(1)
+#define GRL_DIVN		0x170
+#define NCTS_WRI_ANYTIME		BIT(6)
+#define GRL_AUDIO_CFG		0x17C
+#define AUDIO_ZERO			BIT(0)
+#define HIGH_BIT_RATE			BIT(1)
+#define SACD_DST			BIT(2)
+#define DST_NORMAL_DOUBLE		BIT(3)
+#define DSD_INV				BIT(4)
+#define LR_INV				BIT(5)
+#define LR_MIX				BIT(6)
+#define DSD_SEL				BIT(7)
+#define GRL_NCTS		0x184
+#define GRL_CH_SW0		0x18C
+#define GRL_CH_SW1		0x190
+#define GRL_CH_SW2		0x194
+#define CH_SWITCH(from, to)		((from) << ((to) * 3))
+#define GRL_INFOFRM_VER		0x19C
+#define GRL_INFOFRM_TYPE	0x1A0
+#define GRL_INFOFRM_LNG		0x1A4
+#define GRL_MIX_CTRL		0x1B4
+#define MIX_CTRL_SRC_EN			BIT(0)
+#define BYPASS_VOLUME			BIT(1)
+#define MIX_CTRL_FLAT			BIT(7)
+#define GRL_AOUT_CFG		0x1C4
+#define AOUT_BNUM_SEL_MASK		0x03
+#define AOUT_24BIT			0x00
+#define AOUT_20BIT			0x02
+#define AOUT_16BIT			0x03
+#define AOUT_FIFO_ADAP_CTRL		BIT(6)
+#define AOUT_BURST_PREAMBLE_EN		BIT(7)
+#define HIGH_BIT_RATE_PACKET_ALIGN	(AOUT_BURST_PREAMBLE_EN | \
+					 AOUT_FIFO_ADAP_CTRL)
+#define GRL_SHIFT_L1		0x1C0
+#define GRL_SHIFT_R2		0x1B0
+#define AUDIO_PACKET_OFF		BIT(6)
+#define GRL_CFG0		0x24
+#define CFG0_I2S_MODE_MASK		0x3
+#define CFG0_I2S_MODE_RTJ		0x1
+#define CFG0_I2S_MODE_LTJ		0x0
+#define CFG0_I2S_MODE_I2S		0x2
+#define CFG0_W_LENGTH_MASK		0x30
+#define CFG0_W_LENGTH_24BIT		0x00
+#define CFG0_W_LENGTH_16BIT		0x10
+#define GRL_CFG1		0x28
+#define CFG1_EDG_SEL			BIT(0)
+#define CFG1_SPDIF			BIT(1)
+#define CFG1_DVI			BIT(2)
+#define CFG1_HDCP_DEBUG			BIT(3)
+#define GRL_CFG2		0x2c
+#define CFG2_MHL_DE_SEL			BIT(3)
+#define CFG2_MHL_FAKE_DE_SEL		BIT(4)
+#define CFG2_MHL_DATA_REMAP		BIT(5)
+#define CFG2_NOTICE_EN			BIT(6)
+#define CFG2_ACLK_INV			BIT(7)
+#define GRL_CFG3		0x30
+#define CFG3_AES_KEY_INDEX_MASK		0x3f
+#define CFG3_CONTROL_PACKET_DELAY	BIT(6)
+#define CFG3_KSV_LOAD_START		BIT(7)
+#define GRL_CFG4		0x34
+#define CFG4_AES_KEY_LOAD		BIT(4)
+#define CFG4_AV_UNMUTE_EN		BIT(5)
+#define CFG4_AV_UNMUTE_SET		BIT(6)
+#define CFG4_MHL_MODE			BIT(7)
+#define GRL_CFG5		0x38
+#define CFG5_CD_RATIO_MASK	0x8F
+#define CFG5_FS128			(0x1 << 4)
+#define CFG5_FS256			(0x2 << 4)
+#define CFG5_FS384			(0x3 << 4)
+#define CFG5_FS512			(0x4 << 4)
+#define CFG5_FS768			(0x6 << 4)
+#define DUMMY_304		0x304
+#define CHMO_SEL			(0x3 << 2)
+#define CHM1_SEL			(0x3 << 4)
+#define CHM2_SEL			(0x3 << 6)
+#define AUDIO_I2S_NCTS_SEL		BIT(1)
+#define AUDIO_I2S_NCTS_SEL_64		(1 << 1)
+#define AUDIO_I2S_NCTS_SEL_128		(0 << 1)
+#define NEW_GCP_CTRL			BIT(0)
+#define NEW_GCP_CTRL_MERGE		BIT(0)
+#define GRL_L_STATUS_0		0x200
+#define GRL_L_STATUS_1		0x204
+#define GRL_L_STATUS_2		0x208
+#define GRL_L_STATUS_3		0x20c
+#define GRL_L_STATUS_4		0x210
+#define GRL_L_STATUS_5		0x214
+#define GRL_L_STATUS_6		0x218
+#define GRL_L_STATUS_7		0x21c
+#define GRL_L_STATUS_8		0x220
+#define GRL_L_STATUS_9		0x224
+#define GRL_L_STATUS_10		0x228
+#define GRL_L_STATUS_11		0x22c
+#define GRL_L_STATUS_12		0x230
+#define GRL_L_STATUS_13		0x234
+#define GRL_L_STATUS_14		0x238
+#define GRL_L_STATUS_15		0x23c
+#define GRL_L_STATUS_16		0x240
+#define GRL_L_STATUS_17		0x244
+#define GRL_L_STATUS_18		0x248
+#define GRL_L_STATUS_19		0x24c
+#define GRL_L_STATUS_20		0x250
+#define GRL_L_STATUS_21		0x254
+#define GRL_L_STATUS_22		0x258
+#define GRL_L_STATUS_23		0x25c
+#define GRL_R_STATUS_0		0x260
+#define GRL_R_STATUS_1		0x264
+#define GRL_R_STATUS_2		0x268
+#define GRL_R_STATUS_3		0x26c
+#define GRL_R_STATUS_4		0x270
+#define GRL_R_STATUS_5		0x274
+#define GRL_R_STATUS_6		0x278
+#define GRL_R_STATUS_7		0x27c
+#define GRL_R_STATUS_8		0x280
+#define GRL_R_STATUS_9		0x284
+#define GRL_R_STATUS_10		0x288
+#define GRL_R_STATUS_11		0x28c
+#define GRL_R_STATUS_12		0x290
+#define GRL_R_STATUS_13		0x294
+#define GRL_R_STATUS_14		0x298
+#define GRL_R_STATUS_15		0x29c
+#define GRL_R_STATUS_16		0x2a0
+#define GRL_R_STATUS_17		0x2a4
+#define GRL_R_STATUS_18		0x2a8
+#define GRL_R_STATUS_19		0x2ac
+#define GRL_R_STATUS_20		0x2b0
+#define GRL_R_STATUS_21		0x2b4
+#define GRL_R_STATUS_22		0x2b8
+#define GRL_R_STATUS_23		0x2bc
+#define GRL_ABIST_CTRL0		0x2D4
+#define GRL_ABIST_CTRL1		0x2D8
+#define ABIST_EN			BIT(7)
+#define ABIST_DATA_FMT			(0x7 << 0)
+#define VIDEO_CFG_0		0x380
+#define VIDEO_CFG_1		0x384
+#define VIDEO_CFG_2		0x388
+#define VIDEO_CFG_3		0x38c
+#define VIDEO_CFG_4		0x390
+#define VIDEO_SOURCE_SEL		BIT(7)
+#define NORMAL_PATH			(1 << 7)
+#define GEN_RGB				(0 << 7)
+
+#define HDMI_SYS_CFG1C		0x000
+#define HDMI_ON				BIT(0)
+#define HDMI_RST			BIT(1)
+#define ANLG_ON				BIT(2)
+#define CFG10_DVI			BIT(3)
+#define HDMI_TST			BIT(3)
+#define SYS_KEYMASK1			(0xff << 8)
+#define SYS_KEYMASK2			(0xff << 16)
+#define AUD_OUTSYNC_EN			BIT(24)
+#define AUD_OUTSYNC_PRE_EN		BIT(25)
+#define I2CM_ON				BIT(26)
+#define E2PROM_TYPE_8BIT		BIT(27)
+#define MCM_E2PROM_ON			BIT(28)
+#define EXT_E2PROM_ON			BIT(29)
+#define HTPLG_PIN_SEL_OFF		BIT(30)
+#define AES_EFUSE_ENABLE		BIT(31)
+#define HDMI_SYS_CFG20		0x004
+#define DEEP_COLOR_MODE_MASK		(3 << 1)
+#define COLOR_8BIT_MODE			(0 << 1)
+#define COLOR_10BIT_MODE		(1 << 1)
+#define COLOR_12BIT_MODE		(2 << 1)
+#define COLOR_16BIT_MODE		(3 << 1)
+#define DEEP_COLOR_EN			BIT(0)
+#define HDMI_AUDIO_TEST_SEL		BIT(8)
+#define HDMI2P0_EN			BIT(11)
+#define HDMI_OUT_FIFO_EN		BIT(16)
+#define HDMI_OUT_FIFO_CLK_INV		BIT(17)
+#define MHL_MODE_ON			BIT(28)
+#define MHL_PP_MODE			BIT(29)
+#define MHL_SYNC_AUTO_EN		BIT(30)
+#define HDMI_PCLK_FREE_RUN		BIT(31)
+
+#endif