This patch adds support for MediaTek I2C interface

Signed-off-by: Weijie Gao <weijie....@mediatek.com>
---
 drivers/i2c/Kconfig   |   9 +
 drivers/i2c/Makefile  |   1 +
 drivers/i2c/mtk_i2c.c | 822 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 832 insertions(+)
 create mode 100644 drivers/i2c/mtk_i2c.c

diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index be4724bf8e..08b6c7bdcc 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 7e046f809a..920aafb91c 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 0000000000..1d4a93f8c9
--- /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....@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)
+
+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,
+};
+
+enum mtk_trans_op {
+       I2C_MASTER_WR = 1,
+       I2C_MASTER_RD,
+       I2C_MASTER_WRRD,
+};
+
+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 */
+       enum mtk_trans_op 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)
+{
+       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);
+       }
+
+       /*
+        * prepare buffer data to start transfer
+        * three cases here: read, write, write then read
+        */
+       if (priv->op == I2C_MASTER_RD) {
+               /* Clear DMA interrupt flag*/
+               writel(I2C_DMA_INT_FLAG_NONE, priv->pdmabase + REG_INT_FLAG);
+               /* Set DMA direction RX*/
+               writel(I2C_DMA_CON_RX, priv->pdmabase + REG_CON);
+               flush_cache((ulong)msgs->buf, msgs->len);
+               /* Write the rx buffer address to dma register*/
+               writel((ulong)msgs->buf, priv->pdmabase + REG_RX_MEM_ADDR);
+               /* Write the rx length to dma register*/
+               writel(msgs->len, priv->pdmabase + REG_RX_LEN);
+       } else if (priv->op == I2C_MASTER_WR) {
+               /* Clear DMA interrupt flag*/
+               writel(I2C_DMA_INT_FLAG_NONE, priv->pdmabase + REG_INT_FLAG);
+               /* Set DMA direction TX*/
+               writel(I2C_DMA_CON_TX, priv->pdmabase + REG_CON);
+               flush_cache((ulong)msgs->buf, msgs->len);
+               /* 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);
+       } else {
+               /* Clear DMA interrupt flag*/
+               writel(I2C_DMA_INT_FLAG_NONE, priv->pdmabase + REG_INT_FLAG);
+               /* Set DMA direction TX and RX*/
+               writel(I2C_DMA_TX_RX, priv->pdmabase + REG_CON);
+               flush_cache((ulong)msgs->buf, msgs->len);
+               flush_cache((ulong)(msgs + 1)->buf, (msgs + 1)->len);
+               /* Write the tx buffer address to dma register*/
+               writel((ulong)msgs->buf, priv->pdmabase + REG_TX_MEM_ADDR);
+               /* Write the tx buffer address to dma register*/
+               writel((ulong)(msgs + 1)->buf, priv->pdmabase + 
REG_RX_MEM_ADDR);
+               /* Write the tx length to dma register*/
+               writel(msgs->len, priv->pdmabase + REG_TX_LEN);
+               /* Write the rx length to dma register*/
+               writel((msgs + 1)->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;
+                       writel(I2C_RS_MUL_CNFG | I2C_RS_MUL_TRIG |
+                              I2C_TRANSAC_START, priv->base + REG_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_ofdata_to_platdata(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_ofdata_to_platdata,
+       .probe          = mtk_i2c_probe,
+       .priv_auto      = sizeof(struct mtk_i2c_priv),
+       .ops            = &mtk_i2c_ops,
+};
-- 
2.17.1

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