i2c: add support for MediaTek I2C interface

This patch adds support for MediaTek I2C interface

Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>

3 files changed, 832 insertions, 0 deletions

diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index be4724bf8ef..08b6c7bdcc4 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -261,6 +261,15 @@ config SYS_I2C_MESON
 	  internal buffer holding up to 8 bytes for transfers and supports
 	  both 7-bit and 10-bit addresses.
 
+config SYS_I2C_MTK
+	bool "MediaTek I2C driver"
+	help
+	  This selects the MediaTek Integrated Inter Circuit bus driver.
+	  The I2C bus adapter is the base for some other I2C client,
+	  eg: touch, sensors.
+	  If you want to use MediaTek I2C interface, say Y here.
+	  If unsure, say N.
+
 config SYS_I2C_MICROCHIP
 	bool "Microchip I2C driver"
 	help
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index 7e046f809a4..920aafb91c5 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_SYS_I2C_MICROCHIP) += i2c-microchip.o
 obj-$(CONFIG_SYS_I2C_MV) += mv_i2c.o
 obj-$(CONFIG_SYS_I2C_MVTWSI) += mvtwsi.o
 obj-$(CONFIG_SYS_I2C_MXC) += mxc_i2c.o
+obj-$(CONFIG_SYS_I2C_MTK) += mtk_i2c.o
 obj-$(CONFIG_SYS_I2C_NEXELL) += nx_i2c.o
 obj-$(CONFIG_SYS_I2C_NPCM) += npcm_i2c.o
 obj-$(CONFIG_SYS_I2C_OCORES) += ocores_i2c.o
diff --git a/drivers/i2c/mtk_i2c.c b/drivers/i2c/mtk_i2c.c
new file mode 100644
index 00000000000..5528bcd7cce
--- /dev/null
+++ b/drivers/i2c/mtk_i2c.c
@@ -0,0 +1,822 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022 MediaTek Inc. All Rights Reserved.
+ *
+ * Author: Mingming Lee <Mingming.Lee@mediatek.com>
+ *
+ * MediaTek I2C Interface driver
+ */
+
+#include <clk.h>
+#include <cpu_func.h>
+#include <dm.h>
+#include <i2c.h>
+#include <log.h>
+#include <asm/cache.h>
+#include <asm/io.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+
+#define I2C_RS_TRANSFER			BIT(4)
+#define I2C_HS_NACKERR			BIT(2)
+#define I2C_ACKERR			BIT(1)
+#define I2C_TRANSAC_COMP		BIT(0)
+#define I2C_TRANSAC_START		BIT(0)
+#define I2C_RS_MUL_CNFG			BIT(15)
+#define I2C_RS_MUL_TRIG			BIT(14)
+#define I2C_DCM_DISABLE			0x0000
+#define I2C_IO_CONFIG_OPEN_DRAIN	0x0003
+#define I2C_IO_CONFIG_PUSH_PULL		0x0000
+#define I2C_SOFT_RST			0x0001
+#define I2C_FIFO_ADDR_CLR		0x0001
+#define I2C_DELAY_LEN			0x0002
+#define I2C_ST_START_CON		0x8001
+#define I2C_FS_START_CON		0x1800
+#define I2C_TIME_CLR_VALUE		0x0000
+#define I2C_TIME_DEFAULT_VALUE		0x0003
+#define I2C_WRRD_TRANAC_VALUE		0x0002
+#define I2C_RD_TRANAC_VALUE		0x0001
+
+#define I2C_DMA_CON_TX			0x0000
+#define I2C_DMA_CON_RX			0x0001
+#define I2C_DMA_START_EN		0x0001
+#define I2C_DMA_INT_FLAG_NONE		0x0000
+#define I2C_DMA_CLR_FLAG		0x0000
+#define I2C_DMA_TX_RX			0x0000
+#define I2C_DMA_HARD_RST		0x0002
+
+#define MAX_ST_MODE_SPEED		100000
+#define MAX_FS_MODE_SPEED		400000
+#define MAX_HS_MODE_SPEED		3400000
+#define MAX_SAMPLE_CNT_DIV		8
+#define MAX_STEP_CNT_DIV		64
+#define MAX_HS_STEP_CNT_DIV		8
+#define I2C_DEFAULT_CLK_DIV		4
+
+#define MAX_I2C_ADDR			0x7f
+#define MAX_I2C_LEN			0xff
+#define TRANS_ADDR_ONLY			BIT(8)
+#define TRANSFER_TIMEOUT		50000  /* us */
+#define I2C_FIFO_STAT1_MASK		0x001f
+#define TIMING_SAMPLE_OFFSET		8
+#define HS_SAMPLE_OFFSET		12
+#define HS_STEP_OFFSET			8
+
+#define I2C_CONTROL_WRAPPER		BIT(0)
+#define I2C_CONTROL_RS			BIT(1)
+#define I2C_CONTROL_DMA_EN		BIT(2)
+#define I2C_CONTROL_CLK_EXT_EN		BIT(3)
+#define I2C_CONTROL_DIR_CHANGE		BIT(4)
+#define I2C_CONTROL_ACKERR_DET_EN	BIT(5)
+#define I2C_CONTROL_TRANSFER_LEN_CHANGE BIT(6)
+#define I2C_CONTROL_DMAACK		BIT(8)
+#define I2C_CONTROL_ASYNC		BIT(9)
+
+#define I2C_MASTER_WR			BIT(0)
+#define I2C_MASTER_RD			BIT(1)
+#define I2C_MASTER_WRRD			(I2C_MASTER_WR | I2C_MASTER_RD)
+
+enum I2C_REGS_OFFSET {
+	REG_PORT,
+	REG_SLAVE_ADDR,
+	REG_INTR_MASK,
+	REG_INTR_STAT,
+	REG_CONTROL,
+	REG_TRANSFER_LEN,
+	REG_TRANSAC_LEN,
+	REG_DELAY_LEN,
+	REG_TIMING,
+	REG_START,
+	REG_EXT_CONF,
+	REG_FIFO_STAT1,
+	REG_LTIMING,
+	REG_FIFO_STAT,
+	REG_FIFO_THRESH,
+	REG_FIFO_ADDR_CLR,
+	REG_IO_CONFIG,
+	REG_RSV_DEBUG,
+	REG_HS,
+	REG_SOFTRESET,
+	REG_DCM_EN,
+	REG_PATH_DIR,
+	REG_DEBUGSTAT,
+	REG_DEBUGCTRL,
+	REG_TRANSFER_LEN_AUX,
+	REG_CLOCK_DIV,
+	REG_SCL_HL_RATIO,
+	REG_SCL_HS_HL_RATIO,
+	REG_SCL_MIS_COMP_POINT,
+	REG_STA_STOP_AC_TIME,
+	REG_HS_STA_STOP_AC_TIME,
+	REG_DATA_TIME,
+};
+
+enum DMA_REGS_OFFSET {
+	REG_INT_FLAG = 0x0,
+	REG_INT_EN = 0x04,
+	REG_EN = 0x08,
+	REG_RST = 0x0c,
+	REG_CON = 0x18,
+	REG_TX_MEM_ADDR = 0x1c,
+	REG_RX_MEM_ADDR = 0x20,
+	REG_TX_LEN = 0x24,
+	REG_RX_LEN = 0x28,
+};
+
+static const uint mt_i2c_regs_v1[] = {
+	[REG_PORT] = 0x0,
+	[REG_SLAVE_ADDR] = 0x4,
+	[REG_INTR_MASK] = 0x8,
+	[REG_INTR_STAT] = 0xc,
+	[REG_CONTROL] = 0x10,
+	[REG_TRANSFER_LEN] = 0x14,
+	[REG_TRANSAC_LEN] = 0x18,
+	[REG_DELAY_LEN] = 0x1c,
+	[REG_TIMING] = 0x20,
+	[REG_START] = 0x24,
+	[REG_EXT_CONF] = 0x28,
+	[REG_FIFO_STAT1] = 0x2c,
+	[REG_FIFO_STAT] = 0x30,
+	[REG_FIFO_THRESH] = 0x34,
+	[REG_FIFO_ADDR_CLR] = 0x38,
+	[REG_IO_CONFIG] = 0x40,
+	[REG_RSV_DEBUG] = 0x44,
+	[REG_HS] = 0x48,
+	[REG_SOFTRESET] = 0x50,
+	[REG_SOFTRESET] = 0x50,
+	[REG_DCM_EN] = 0x54,
+	[REG_DEBUGSTAT] = 0x64,
+	[REG_DEBUGCTRL] = 0x68,
+	[REG_TRANSFER_LEN_AUX] = 0x6c,
+	[REG_CLOCK_DIV] = 0x70,
+	[REG_SCL_HL_RATIO] = 0x74,
+	[REG_SCL_HS_HL_RATIO] = 0x78,
+	[REG_SCL_MIS_COMP_POINT] = 0x7c,
+	[REG_STA_STOP_AC_TIME] = 0x80,
+	[REG_HS_STA_STOP_AC_TIME] = 0x84,
+	[REG_DATA_TIME] = 0x88,
+};
+
+static const uint mt_i2c_regs_v2[] = {
+	[REG_PORT] = 0x0,
+	[REG_SLAVE_ADDR] = 0x4,
+	[REG_INTR_MASK] = 0x8,
+	[REG_INTR_STAT] = 0xc,
+	[REG_CONTROL] = 0x10,
+	[REG_TRANSFER_LEN] = 0x14,
+	[REG_TRANSAC_LEN] = 0x18,
+	[REG_DELAY_LEN] = 0x1c,
+	[REG_TIMING] = 0x20,
+	[REG_START] = 0x24,
+	[REG_EXT_CONF] = 0x28,
+	[REG_LTIMING] = 0x2c,
+	[REG_HS] = 0x30,
+	[REG_IO_CONFIG] = 0x34,
+	[REG_FIFO_ADDR_CLR] = 0x38,
+	[REG_TRANSFER_LEN_AUX] = 0x44,
+	[REG_CLOCK_DIV] = 0x48,
+	[REG_SOFTRESET] = 0x50,
+	[REG_DEBUGSTAT] = 0xe0,
+	[REG_DEBUGCTRL] = 0xe8,
+	[REG_FIFO_STAT] = 0xf4,
+	[REG_FIFO_THRESH] = 0xf8,
+	[REG_DCM_EN] = 0xf88,
+};
+
+struct mtk_i2c_soc_data {
+	const uint *regs;
+	uint dma_sync: 1;
+};
+
+struct mtk_i2c_priv {
+	/* set in i2c probe */
+	void __iomem *base;		/* i2c base addr */
+	void __iomem *pdmabase;		/* dma base address*/
+	struct clk clk_main;		/* main clock for i2c bus */
+	struct clk clk_dma;		/* DMA clock for i2c via DMA */
+	const struct mtk_i2c_soc_data *soc_data; /* Compatible data for different IC */
+	int op;				/* operation mode */
+	bool zero_len;			/* Only transfer slave address, no data */
+	bool pushpull;			/* push pull mode or open drain mode */
+	bool filter_msg;		/* filter msg error log */
+	bool auto_restart;		/* restart mode */
+	bool ignore_restart_irq;	/* ignore restart IRQ */
+	uint speed;			/* i2c speed, unit: hz */
+};
+
+static inline void i2c_writel(struct mtk_i2c_priv *priv, uint reg, uint value)
+{
+	u32 offset = priv->soc_data->regs[reg];
+
+	writel(value, priv->base + offset);
+}
+
+static inline uint i2c_readl(struct mtk_i2c_priv *priv, uint offset)
+{
+	return readl(priv->base + priv->soc_data->regs[offset]);
+}
+
+static int mtk_i2c_clk_enable(struct mtk_i2c_priv *priv)
+{
+	int ret;
+
+	ret = clk_enable(&priv->clk_main);
+	if (ret)
+		return log_msg_ret("enable clk_main", ret);
+
+	ret = clk_enable(&priv->clk_dma);
+	if (ret)
+		return log_msg_ret("enable clk_dma", ret);
+
+	return 0;
+}
+
+static int mtk_i2c_clk_disable(struct mtk_i2c_priv *priv)
+{
+	int ret;
+
+	ret = clk_disable(&priv->clk_dma);
+	if (ret)
+		return log_msg_ret("disable clk_dma", ret);
+
+	ret = clk_disable(&priv->clk_main);
+	if (ret)
+		return log_msg_ret("disable clk_main", ret);
+
+	return 0;
+}
+
+static void mtk_i2c_init_hw(struct mtk_i2c_priv *priv)
+{
+	uint control_reg;
+
+	writel(I2C_DMA_HARD_RST, priv->pdmabase + REG_RST);
+	writel(I2C_DMA_CLR_FLAG, priv->pdmabase + REG_RST);
+	i2c_writel(priv, REG_SOFTRESET, I2C_SOFT_RST);
+	/* set ioconfig */
+	if (priv->pushpull)
+		i2c_writel(priv, REG_IO_CONFIG, I2C_IO_CONFIG_PUSH_PULL);
+	else
+		i2c_writel(priv, REG_IO_CONFIG, I2C_IO_CONFIG_OPEN_DRAIN);
+
+	i2c_writel(priv, REG_DCM_EN, I2C_DCM_DISABLE);
+	control_reg = I2C_CONTROL_ACKERR_DET_EN | I2C_CONTROL_CLK_EXT_EN;
+	if (priv->soc_data->dma_sync)
+		control_reg |= I2C_CONTROL_DMAACK | I2C_CONTROL_ASYNC;
+	i2c_writel(priv, REG_CONTROL, control_reg);
+	i2c_writel(priv, REG_DELAY_LEN, I2C_DELAY_LEN);
+}
+
+/*
+ * Calculate i2c port speed
+ *
+ * Hardware design:
+ * i2c_bus_freq = parent_clk / (clock_div * 2 * sample_cnt * step_cnt)
+ * clock_div: fixed in hardware, but may be various in different SoCs
+ *
+ * The calculation want to pick the highest bus frequency that is still
+ * less than or equal to target_speed. The calculation try to get
+ * sample_cnt and step_cn
+ * @param[in]
+ *     clk_src: i2c clock source
+ * @param[out]
+ *     timing_step_cnt: step cnt calculate result
+ * @param[out]
+ *     timing_sample_cnt: sample cnt calculate result
+ * @return
+ *     0, set speed successfully.
+ *     -EINVAL, Unsupported speed.
+ */
+static int mtk_i2c_calculate_speed(uint clk_src,
+				   uint target_speed,
+				   uint *timing_step_cnt,
+				   uint *timing_sample_cnt)
+{
+	uint base_sample_cnt = MAX_SAMPLE_CNT_DIV;
+	uint base_step_cnt;
+	uint max_step_cnt;
+	uint sample_cnt;
+	uint step_cnt;
+	uint opt_div;
+	uint best_mul;
+	uint cnt_mul;
+
+	if (target_speed > MAX_HS_MODE_SPEED)
+		target_speed = MAX_HS_MODE_SPEED;
+
+	if (target_speed > MAX_FS_MODE_SPEED)
+		max_step_cnt = MAX_HS_STEP_CNT_DIV;
+	else
+		max_step_cnt = MAX_STEP_CNT_DIV;
+
+	base_step_cnt = max_step_cnt;
+	/* Find the best combination */
+	opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed);
+	best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt;
+
+	/*
+	 * Search for the best pair (sample_cnt, step_cnt) with
+	 * 0 < sample_cnt < MAX_SAMPLE_CNT_DIV
+	 * 0 < step_cnt < max_step_cnt
+	 * sample_cnt * step_cnt >= opt_div
+	 * optimizing for sample_cnt * step_cnt being minimal
+	 */
+	for (sample_cnt = 1; sample_cnt <= MAX_SAMPLE_CNT_DIV; sample_cnt++) {
+		step_cnt = DIV_ROUND_UP(opt_div, sample_cnt);
+		cnt_mul = step_cnt * sample_cnt;
+		if (step_cnt > max_step_cnt)
+			continue;
+
+		if (cnt_mul < best_mul) {
+			best_mul = cnt_mul;
+			base_sample_cnt = sample_cnt;
+			base_step_cnt = step_cnt;
+			if (best_mul == opt_div)
+				break;
+		}
+	}
+
+	sample_cnt = base_sample_cnt;
+	step_cnt = base_step_cnt;
+
+	if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) {
+		/*
+		 * In this case, hardware can't support such
+		 * low i2c_bus_freq
+		 */
+		debug("Unsupported speed(%uhz)\n", target_speed);
+		return log_msg_ret("calculate speed", -EINVAL);
+	}
+
+	*timing_step_cnt = step_cnt - 1;
+	*timing_sample_cnt = sample_cnt - 1;
+
+	return 0;
+}
+
+/*
+ * mtk_i2c_set_speed
+ *
+ * @par Description
+ *     Calculate i2c speed and write sample_cnt, step_cnt to TIMING register.
+ * @param[in]
+ *     dev: udevice pointer, struct udevice contains i2c source clock,
+ *     clock divide and speed.
+ * @return
+ *     0, set speed successfully.\n
+ *     error code from mtk_i2c_calculate_speed().
+ */
+static int mtk_i2c_set_speed(struct udevice *dev, uint speed)
+{
+	struct mtk_i2c_priv *priv = dev_get_priv(dev);
+	uint high_speed_reg;
+	uint sample_cnt;
+	uint timing_reg;
+	uint step_cnt;
+	uint clk_src;
+	int ret = 0;
+
+	priv->speed = speed;
+	if (mtk_i2c_clk_enable(priv))
+		return log_msg_ret("set_speed enable clk", -1);
+
+	clk_src = clk_get_rate(&priv->clk_main) / I2C_DEFAULT_CLK_DIV;
+	i2c_writel(priv, REG_CLOCK_DIV, (I2C_DEFAULT_CLK_DIV - 1));
+	if (priv->speed > MAX_FS_MODE_SPEED) {
+		/* Set master code speed register */
+		ret = mtk_i2c_calculate_speed(clk_src, MAX_FS_MODE_SPEED,
+					      &step_cnt, &sample_cnt);
+		if (ret < 0)
+			goto exit;
+
+		timing_reg = (sample_cnt << TIMING_SAMPLE_OFFSET) | step_cnt;
+		i2c_writel(priv, REG_TIMING, timing_reg);
+		/* Set the high speed mode register */
+		ret = mtk_i2c_calculate_speed(clk_src, priv->speed,
+					      &step_cnt, &sample_cnt);
+		if (ret < 0)
+			goto exit;
+
+		high_speed_reg = I2C_TIME_DEFAULT_VALUE |
+				(sample_cnt << HS_SAMPLE_OFFSET) |
+				(step_cnt << HS_STEP_OFFSET);
+		i2c_writel(priv, REG_HS, high_speed_reg);
+	} else {
+		ret = mtk_i2c_calculate_speed(clk_src, priv->speed,
+					      &step_cnt, &sample_cnt);
+		if (ret < 0)
+			goto exit;
+
+		timing_reg = (sample_cnt << TIMING_SAMPLE_OFFSET) | step_cnt;
+		/* Disable the high speed transaction */
+		high_speed_reg = I2C_TIME_CLR_VALUE;
+		i2c_writel(priv, REG_TIMING, timing_reg);
+		i2c_writel(priv, REG_HS, high_speed_reg);
+	}
+exit:
+	if (mtk_i2c_clk_disable(priv))
+		return log_msg_ret("set_speed disable clk", -1);
+
+	return ret;
+}
+
+/*
+ * mtk_i2c_do_transfer
+ *
+ * @par Description
+ *     Configure i2c register and trigger transfer.
+ * @param[in]
+ *     priv: mtk_i2cmtk_i2c_priv pointer, struct mtk_i2c_priv contains register base\n
+ *     address, operation mode, interrupt status and i2c driver data.
+ * @param[in]
+ *     msgs: i2c_msg pointer, struct i2c_msg contains slave\n
+ *     address, operation mode, msg length and data buffer.
+ * @param[in]
+ *     num: i2c_msg number.
+ * @param[in]
+ *     left_num: left i2c_msg number.
+ * @return
+ *     0, i2c transfer successfully.\n
+ *     -ETIMEDOUT, i2c transfer timeout.\n
+ *     -EREMOTEIO, i2c transfer ack error.
+ */
+static int mtk_i2c_do_transfer(struct mtk_i2c_priv *priv,
+			       struct i2c_msg *msgs,
+			       int num, int left_num)
+{
+	struct i2c_msg *msg_rx = NULL;
+	uint restart_flag = 0;
+	uint trans_error = 0;
+	uint irq_stat = 0;
+	uint tmo_poll = 0;
+	uint control_reg;
+	bool tmo = false;
+	uint start_reg;
+	uint addr_reg;
+	int ret = 0;
+
+	if (priv->auto_restart)
+		restart_flag = I2C_RS_TRANSFER;
+
+	control_reg = i2c_readl(priv, REG_CONTROL) &
+		~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
+
+	if (priv->speed > MAX_FS_MODE_SPEED || num > 1)
+		control_reg |= I2C_CONTROL_RS;
+
+	if (priv->op == I2C_MASTER_WRRD)
+		control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS;
+
+	control_reg |= I2C_CONTROL_DMA_EN;
+	i2c_writel(priv, REG_CONTROL, control_reg);
+
+	/* set start condition */
+	if (priv->speed <= MAX_ST_MODE_SPEED)
+		i2c_writel(priv, REG_EXT_CONF, I2C_ST_START_CON);
+	else
+		i2c_writel(priv, REG_EXT_CONF, I2C_FS_START_CON);
+
+	addr_reg = msgs->addr << 1;
+	if (priv->op == I2C_MASTER_RD)
+		addr_reg |= I2C_M_RD;
+	if (priv->zero_len)
+		i2c_writel(priv, REG_SLAVE_ADDR, addr_reg | TRANS_ADDR_ONLY);
+	else
+		i2c_writel(priv, REG_SLAVE_ADDR, addr_reg);
+
+	/* clear interrupt status */
+	i2c_writel(priv, REG_INTR_STAT, restart_flag | I2C_HS_NACKERR |
+		   I2C_ACKERR | I2C_TRANSAC_COMP);
+	i2c_writel(priv, REG_FIFO_ADDR_CLR, I2C_FIFO_ADDR_CLR);
+
+	/* enable interrupt */
+	i2c_writel(priv, REG_INTR_MASK, restart_flag | I2C_HS_NACKERR |
+		   I2C_ACKERR | I2C_TRANSAC_COMP);
+
+	/* set transfer and transaction len */
+	if (priv->op == I2C_MASTER_WRRD) {
+		i2c_writel(priv, REG_TRANSFER_LEN, msgs->len);
+		i2c_writel(priv, REG_TRANSFER_LEN_AUX, (msgs + 1)->len);
+		i2c_writel(priv, REG_TRANSAC_LEN, I2C_WRRD_TRANAC_VALUE);
+	} else {
+		i2c_writel(priv, REG_TRANSFER_LEN, msgs->len);
+		i2c_writel(priv, REG_TRANSAC_LEN, num);
+	}
+
+	/* Clear DMA interrupt flag */
+	writel(I2C_DMA_INT_FLAG_NONE, priv->pdmabase + REG_INT_FLAG);
+
+	/* Flush cache for first msg */
+	flush_cache((ulong)msgs->buf, msgs->len);
+
+	/*
+	 * prepare buffer data to start transfer
+	 * three cases here: read, write, write then read
+	 */
+	if (priv->op & I2C_MASTER_WR) {
+		/* Set DMA direction TX (w/ or w/o RX) */
+		writel(I2C_DMA_CON_TX, priv->pdmabase + REG_CON);
+
+		/* Write the tx buffer address to dma register */
+		writel((ulong)msgs->buf, priv->pdmabase + REG_TX_MEM_ADDR);
+		/* Write the tx length to dma register */
+		writel(msgs->len, priv->pdmabase + REG_TX_LEN);
+
+		if (priv->op & I2C_MASTER_RD) {
+			/* write then read */
+			msg_rx = msgs + 1;
+
+			/* Flush cache for second msg */
+			flush_cache((ulong)msg_rx->buf, msg_rx->len);
+		}
+	}
+
+	if (priv->op & I2C_MASTER_RD) {
+		if (!msg_rx) {
+			/* Set DMA direction RX */
+			writel(I2C_DMA_CON_RX, priv->pdmabase + REG_CON);
+
+			msg_rx = msgs;
+		}
+
+		/* Write the rx buffer address to dma register */
+		writel((ulong)msg_rx->buf, priv->pdmabase + REG_RX_MEM_ADDR);
+		/* Write the rx length to dma register */
+		writel(msg_rx->len, priv->pdmabase + REG_RX_LEN);
+	}
+
+	writel(I2C_DMA_START_EN, priv->pdmabase + REG_EN);
+
+	if (!priv->auto_restart) {
+		start_reg = I2C_TRANSAC_START;
+	} else {
+		start_reg = I2C_TRANSAC_START | I2C_RS_MUL_TRIG;
+		if (left_num >= 1)
+			start_reg |= I2C_RS_MUL_CNFG;
+	}
+	i2c_writel(priv, REG_START, start_reg);
+
+	for (;;) {
+		irq_stat = i2c_readl(priv, REG_INTR_STAT);
+
+		/* ignore the first restart irq after the master code */
+		if (priv->ignore_restart_irq && (irq_stat & restart_flag)) {
+			priv->ignore_restart_irq = false;
+			irq_stat = 0;
+			i2c_writel(priv, REG_START, I2C_RS_MUL_CNFG |
+				   I2C_RS_MUL_TRIG | I2C_TRANSAC_START);
+		}
+
+		if (irq_stat & (I2C_TRANSAC_COMP | restart_flag)) {
+			tmo = false;
+			if (irq_stat & (I2C_HS_NACKERR | I2C_ACKERR))
+				trans_error = 1;
+
+			break;
+		}
+		udelay(1);
+		if (tmo_poll++ >= TRANSFER_TIMEOUT) {
+			tmo = true;
+			break;
+		}
+	}
+
+	/* clear interrupt mask */
+	i2c_writel(priv, REG_INTR_MASK, ~(restart_flag | I2C_HS_NACKERR |
+		  I2C_ACKERR | I2C_TRANSAC_COMP));
+
+	if (!tmo && trans_error != 0) {
+		if (tmo) {
+			ret = -ETIMEDOUT;
+			if (!priv->filter_msg)
+				debug("I2C timeout! addr: 0x%x,\n", msgs->addr);
+		} else {
+			ret = -EREMOTEIO;
+			if (!priv->filter_msg)
+				debug("I2C ACKERR! addr: 0x%x,IRQ:0x%x\n",
+				      msgs->addr, irq_stat);
+		}
+		mtk_i2c_init_hw(priv);
+	}
+
+	return ret;
+}
+
+/*
+ * mtk_i2c_transfer
+ *
+ * @par Description
+ *     Common i2c transfer API. Set i2c transfer mode according to i2c_msg\n
+ *     information, then call mtk_i2c_do_transfer() to configure i2c register\n
+ *     and trigger transfer.
+ * @param[in]
+ *     dev: udevice pointer, struct udevice contains struct mtk_i2c_priv, \n
+ *	   struct mtk_i2c_priv contains register base\n
+ *     address, operation mode, interrupt status and i2c driver data.
+ * @param[in]
+ *     msgs: i2c_msg pointer, struct i2c_msg contains slave\n
+ *     address, operation mode, msg length and data buffer.
+ * @param[in]
+ *     num: i2c_msg number.
+ * @return
+ *     i2c_msg number, i2c transfer successfully.\n
+ *     -EINVAL, msg length is more than 16\n
+ *     use DMA MODE or slave address more than 0x7f.\n
+ *     error code from mtk_i2c_init_base().\n
+ *     error code from mtk_i2c_set_speed().\n
+ *     error code from mtk_i2c_do_transfer().
+ */
+static int mtk_i2c_transfer(struct udevice *dev, struct i2c_msg *msg,
+			    int nmsgs)
+{
+	struct mtk_i2c_priv *priv = dev_get_priv(dev);
+	int left_num;
+	uint num_cnt;
+	int ret;
+
+	priv->auto_restart = true;
+	left_num = nmsgs;
+	if (mtk_i2c_clk_enable(priv))
+		return log_msg_ret("transfer enable clk", -1);
+
+	for (num_cnt = 0; num_cnt < nmsgs; num_cnt++) {
+		if (((msg + num_cnt)->addr) > MAX_I2C_ADDR) {
+			ret = -EINVAL;
+			goto err_exit;
+		}
+		if ((msg + num_cnt)->len > MAX_I2C_LEN) {
+			ret = -EINVAL;
+			goto err_exit;
+		}
+	}
+
+	/* check if we can skip restart and optimize using WRRD mode */
+	if (priv->auto_restart && nmsgs == 2) {
+		if (!(msg[0].flags & I2C_M_RD) && (msg[1].flags & I2C_M_RD) &&
+		    msg[0].addr == msg[1].addr) {
+			priv->auto_restart = false;
+		}
+	}
+
+	if (priv->auto_restart && nmsgs >= 2 && priv->speed > MAX_FS_MODE_SPEED)
+		/* ignore the first restart irq after the master code,
+		 * otherwise the first transfer will be discarded.
+		 */
+		priv->ignore_restart_irq = true;
+	else
+		priv->ignore_restart_irq = false;
+
+	while (left_num--) {
+		/* transfer slave address only to support devices detect */
+		if (!msg->buf)
+			priv->zero_len = true;
+		else
+			priv->zero_len = false;
+
+		if (msg->flags & I2C_M_RD)
+			priv->op = I2C_MASTER_RD;
+		else
+			priv->op = I2C_MASTER_WR;
+
+		if (!priv->auto_restart) {
+			if (nmsgs > 1) {
+				/* combined two messages into one transaction */
+				priv->op = I2C_MASTER_WRRD;
+				left_num--;
+			}
+		}
+		ret = mtk_i2c_do_transfer(priv, msg, nmsgs, left_num);
+		if (ret < 0)
+			goto err_exit;
+		msg++;
+	}
+	ret = 0;
+
+err_exit:
+	if (mtk_i2c_clk_disable(priv))
+		return log_msg_ret("transfer disable clk", -1);
+
+	return ret;
+}
+
+static int mtk_i2c_of_to_plat(struct udevice *dev)
+{
+	struct mtk_i2c_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	priv->base = dev_remap_addr_index(dev, 0);
+	priv->pdmabase = dev_remap_addr_index(dev, 1);
+	ret = clk_get_by_index(dev, 0, &priv->clk_main);
+	if (ret)
+		return log_msg_ret("clk_get_by_index 0", ret);
+
+	ret = clk_get_by_index(dev, 1, &priv->clk_dma);
+
+	return ret;
+}
+
+static int mtk_i2c_probe(struct udevice *dev)
+{
+	struct mtk_i2c_priv *priv = dev_get_priv(dev);
+
+	priv->soc_data = (struct mtk_i2c_soc_data *)dev_get_driver_data(dev);
+
+	if (mtk_i2c_clk_enable(priv))
+		return log_msg_ret("probe enable clk", -1);
+
+	mtk_i2c_init_hw(priv);
+
+	if (mtk_i2c_clk_disable(priv))
+		return log_msg_ret("probe disable clk", -1);
+
+	return 0;
+}
+
+static int mtk_i2c_deblock(struct udevice *dev)
+{
+	struct mtk_i2c_priv *priv = dev_get_priv(dev);
+
+	if (mtk_i2c_clk_enable(priv))
+		return log_msg_ret("deblock enable clk", -1);
+
+	mtk_i2c_init_hw(priv);
+
+	if (mtk_i2c_clk_disable(priv))
+		return log_msg_ret("deblock disable clk", -1);
+
+	return 0;
+}
+
+static const struct mtk_i2c_soc_data mt76xx_soc_data = {
+	.regs = mt_i2c_regs_v1,
+	.dma_sync = 0,
+};
+
+static const struct mtk_i2c_soc_data mt7981_soc_data = {
+	.regs = mt_i2c_regs_v1,
+	.dma_sync = 1,
+};
+
+static const struct mtk_i2c_soc_data mt7986_soc_data = {
+	.regs = mt_i2c_regs_v1,
+	.dma_sync = 1,
+};
+
+static const struct mtk_i2c_soc_data mt8183_soc_data = {
+	.regs = mt_i2c_regs_v2,
+	.dma_sync = 1,
+};
+
+static const struct mtk_i2c_soc_data mt8518_soc_data = {
+	.regs = mt_i2c_regs_v1,
+	.dma_sync = 0,
+};
+
+static const struct mtk_i2c_soc_data mt8512_soc_data = {
+	.regs = mt_i2c_regs_v1,
+	.dma_sync = 1,
+};
+
+static const struct dm_i2c_ops mtk_i2c_ops = {
+	.xfer		= mtk_i2c_transfer,
+	.set_bus_speed	= mtk_i2c_set_speed,
+	.deblock	= mtk_i2c_deblock,
+};
+
+static const struct udevice_id mtk_i2c_ids[] = {
+	{
+		.compatible = "mediatek,mt7622-i2c",
+		.data = (ulong)&mt76xx_soc_data,
+	}, {
+		.compatible = "mediatek,mt7623-i2c",
+		.data = (ulong)&mt76xx_soc_data,
+	}, {
+		.compatible = "mediatek,mt7629-i2c",
+		.data = (ulong)&mt76xx_soc_data,
+	}, {
+		.compatible = "mediatek,mt7981-i2c",
+		.data = (ulong)&mt7981_soc_data,
+	}, {
+		.compatible = "mediatek,mt7986-i2c",
+		.data = (ulong)&mt7986_soc_data,
+	}, {
+		.compatible = "mediatek,mt8183-i2c",
+		.data = (ulong)&mt8183_soc_data,
+	}, {
+		.compatible = "mediatek,mt8512-i2c",
+		.data = (ulong)&mt8512_soc_data,
+	}, {
+		.compatible = "mediatek,mt8518-i2c",
+		.data = (ulong)&mt8518_soc_data,
+	}
+};
+
+U_BOOT_DRIVER(mtk_i2c) = {
+	.name		= "mtk_i2c",
+	.id		= UCLASS_I2C,
+	.of_match	= mtk_i2c_ids,
+	.of_to_plat	= mtk_i2c_of_to_plat,
+	.probe		= mtk_i2c_probe,
+	.priv_auto	= sizeof(struct mtk_i2c_priv),
+	.ops		= &mtk_i2c_ops,
+};