From: Mingming Lee <mingming....@mediatek.com>

Add MediaTek I2C basic driver

Signed-off-by: Mingming Lee <mingming....@mediatek.com>

---
Changes for v2:
   - using error number defined in include/linux/errno.h
---
 drivers/i2c/Kconfig  |   9 +
 drivers/i2c/Makefile |   1 +
 drivers/i2c/mt_i2c.c | 617 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 627 insertions(+)
 create mode 100644 drivers/i2c/mt_i2c.c

diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index dec6dc9dfa..103688ed36 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -159,6 +159,15 @@ 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"
+       default n
+       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_MXC
        bool "NXP MXC I2C driver"
        help
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index e851ec462e..7227742f8d 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_SYS_I2C_LPC32XX) += lpc32xx_i2c.o
 obj-$(CONFIG_SYS_I2C_MESON) += meson_i2c.o
 obj-$(CONFIG_SYS_I2C_MVTWSI) += mvtwsi.o
 obj-$(CONFIG_SYS_I2C_MXC) += mxc_i2c.o
+obj-$(CONFIG_SYS_I2C_MTK) += mt_i2c.o
 obj-$(CONFIG_SYS_I2C_NEXELL) += nx_i2c.o
 obj-$(CONFIG_SYS_I2C_OCTEON) += octeon_i2c.o
 obj-$(CONFIG_SYS_I2C_OMAP24XX) += omap24xx_i2c.o
diff --git a/drivers/i2c/mt_i2c.c b/drivers/i2c/mt_i2c.c
new file mode 100644
index 0000000000..be6262d3d2
--- /dev/null
+++ b/drivers/i2c/mt_i2c.c
@@ -0,0 +1,617 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MediaTek I2C Interface driver
+ *
+ * Copyright (C) 2020 MediaTek Inc.
+ * Author: Mingming Lee <mingming....@mediatek.com>
+ */
+
+#include <asm/cache.h>
+#include <asm/io.h>
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <i2c.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+
+#define I2C_OK                 0
+
+#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_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 {
+       OFFSET_PORT = 0x0,
+       OFFSET_SLAVE_ADDR = 0x04,
+       OFFSET_INTR_MASK = 0x08,
+       OFFSET_INTR_STAT = 0x0C,
+       OFFSET_CONTROL = 0x10,
+       OFFSET_TRANSFER_LEN = 0x14,
+       OFFSET_TRANSAC_LEN  = 0x18,
+       OFFSET_DELAY_LEN = 0x1C,
+       OFFSET_TIMING = 0x20,
+       OFFSET_START = 0x24,
+       OFFSET_EXT_CONF = 0x28,
+       OFFSET_FIFO_STAT1 = 0x2C,
+       OFFSET_FIFO_STAT = 0x30,
+       OFFSET_FIFO_THRESH = 0x34,
+       OFFSET_FIFO_ADDR_CLR = 0x38,
+       OFFSET_IO_CONFIG = 0x40,
+       OFFSET_RSV_DEBUG = 0x44,
+       OFFSET_HS = 0x48,
+       OFFSET_SOFTRESET = 0x50,
+       OFFSET_DCM_EN = 0x54,
+       OFFSET_DEBUGSTAT = 0x64,
+       OFFSET_DEBUGCTRL = 0x68,
+       OFFSET_TRANSFER_LEN_AUX = 0x6C,
+       OFFSET_CLOCK_DIV = 0x70,
+       OFFSET_SCL_HL_RATIO = 0x74,
+       OFFSET_SCL_HS_HL_RATIO = 0x78,
+       OFFSET_SCL_MIS_COMP_POINT = 0x7C,
+       OFFSET_STA_STOP_AC_TIME = 0x80,
+       OFFSET_HS_STA_STOP_AC_TIME = 0x84,
+       OFFSET_DATA_TIME = 0x88,
+};
+
+enum DMA_REGS_OFFSET {
+       OFFSET_INT_FLAG = 0x0,
+       OFFSET_INT_EN = 0x04,
+       OFFSET_EN = 0x08,
+       OFFSET_RST = 0x0C,
+       OFFSET_CON = 0x18,
+       OFFSET_TX_MEM_ADDR = 0x1C,
+       OFFSET_RX_MEM_ADDR = 0x20,
+       OFFSET_TX_LEN = 0x24,
+       OFFSET_RX_LEN = 0x28,
+};
+
+enum mtk_trans_op {
+       I2C_MASTER_WR = 1,
+       I2C_MASTER_RD,
+       I2C_MASTER_WRRD,
+};
+
+struct mtk_i2c_soc_data {
+       u8 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;
+       enum mtk_trans_op op;
+       bool   zero_len;
+       bool   pushpull;            /* open drain */
+       bool   filter_msg;          /* filter msg error log */
+       bool   auto_restart;
+       bool ignore_restart_irq;
+       u32 speed;                 /* hz */
+       u8 *tx_buff;
+       u8 *rx_buff;
+};
+
+static inline void i2c_writel(struct mtk_i2c_priv *priv, u8 offset, u32 value)
+{
+       writel(value, (priv->base + offset));
+}
+
+static inline u32 i2c_readl(struct mtk_i2c_priv *priv, u8 offset)
+{
+       return readl(priv->base + offset);
+}
+
+static void mtk_i2c_clk_enable(struct mtk_i2c_priv *priv)
+{
+       clk_enable(&priv->clk_main);
+       clk_enable(&priv->clk_dma);
+}
+
+static void mtk_i2c_clk_disable(struct mtk_i2c_priv *priv)
+{
+       clk_disable(&priv->clk_dma);
+       clk_disable(&priv->clk_main);
+}
+
+static void mtk_i2c_init_hw(struct mtk_i2c_priv *priv)
+{
+       u16 control_reg;
+
+       writel(I2C_DMA_HARD_RST, priv->pdmabase + OFFSET_RST);
+       writel(I2C_DMA_CLR_FLAG, priv->pdmabase + OFFSET_RST);
+       i2c_writel(priv, OFFSET_SOFTRESET, I2C_SOFT_RST);
+       /* set ioconfig */
+       if (priv->pushpull)
+               i2c_writel(priv, OFFSET_IO_CONFIG, I2C_IO_CONFIG_PUSH_PULL);
+       else
+               i2c_writel(priv, OFFSET_IO_CONFIG, I2C_IO_CONFIG_OPEN_DRAIN);
+
+       i2c_writel(priv, OFFSET_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, OFFSET_CONTROL, control_reg);
+       i2c_writel(priv, OFFSET_DELAY_LEN, I2C_DELAY_LEN);
+}
+
+static int mtk_i2c_calculate_speed(struct mtk_i2c_priv *priv,
+                                  u32 clk_src,
+                                  u32 target_speed,
+                                  u32 *timing_step_cnt,
+                                  u32 *timing_sample_cnt)
+{
+       u32 step_cnt;
+       u32 sample_cnt;
+       u32 max_step_cnt;
+       u32 base_sample_cnt = MAX_SAMPLE_CNT_DIV;
+       u32 base_step_cnt;
+       u32 opt_div;
+       u32 best_mul;
+       u32 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 -EINVAL;
+       }
+
+       *timing_step_cnt = step_cnt - 1;
+       *timing_sample_cnt = sample_cnt - 1;
+       return 0;
+}
+
+static int mtk_i2c_set_speed(struct udevice *dev, uint speed)
+{
+       u32 clk_src;
+       u32 step_cnt;
+       u32 sample_cnt;
+       u16 timing_reg;
+       u16 high_speed_reg;
+       int ret = 0;
+       struct mtk_i2c_priv *priv = dev_get_priv(dev);
+
+       priv->speed = speed;
+       mtk_i2c_clk_enable(priv);
+       clk_src = clk_get_rate(&priv->clk_main) /
+                       I2C_DEFAULT_CLK_DIV;
+       i2c_writel(priv, OFFSET_CLOCK_DIV, (I2C_DEFAULT_CLK_DIV - 1));
+       if (priv->speed > MAX_FS_MODE_SPEED) {
+               /* Set master code speed register */
+               ret = mtk_i2c_calculate_speed(priv, clk_src, MAX_FS_MODE_SPEED,
+                                             &step_cnt, &sample_cnt);
+               if (ret < 0)
+                       goto exit;
+
+               timing_reg = (sample_cnt << TIMING_SAMPLE_OFFSET) | step_cnt;
+               writel(timing_reg, priv->base + OFFSET_TIMING);
+               /* Set the high speed mode register */
+               ret = mtk_i2c_calculate_speed(priv, 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);
+               writel(high_speed_reg, priv->base + OFFSET_HS);
+       } else {
+               ret = mtk_i2c_calculate_speed(priv, 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;
+               writel(timing_reg, priv->base + OFFSET_TIMING);
+               writel(high_speed_reg, priv->base + OFFSET_HS);
+       }
+exit:
+       mtk_i2c_clk_disable(priv);
+       return ret;
+}
+
+static int mtk_i2c_do_transfer(struct mtk_i2c_priv *priv,
+                              struct i2c_msg *msgs,
+                              int num, int left_num)
+{
+       u16 addr_reg;
+       u16 start_reg;
+       u16 control_reg;
+       u16 restart_flag = 0;
+       u16     irq_stat = 0;
+       u8 trans_error = 0;
+       bool tmo = false;
+       u8 *ptr = msgs->buf;
+       u16 data_size = msgs->len;
+       u32 tmo_poll = 0;
+       int ret;
+
+       if (priv->auto_restart)
+               restart_flag = I2C_RS_TRANSFER;
+
+       control_reg = i2c_readl(priv, OFFSET_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, OFFSET_CONTROL, control_reg);
+
+       /* set start condition */
+       if (priv->speed <= MAX_ST_MODE_SPEED)
+               i2c_writel(priv, OFFSET_EXT_CONF, I2C_ST_START_CON);
+       else
+               i2c_writel(priv, OFFSET_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, OFFSET_SLAVE_ADDR, addr_reg | TRANS_ADDR_ONLY);
+       else
+               i2c_writel(priv, OFFSET_SLAVE_ADDR, addr_reg);
+
+       /* clear interrupt status */
+       i2c_writel(priv, OFFSET_INTR_STAT, restart_flag | I2C_HS_NACKERR |
+                                               I2C_ACKERR | I2C_TRANSAC_COMP);
+               i2c_writel(priv, OFFSET_FIFO_ADDR_CLR, I2C_FIFO_ADDR_CLR);
+
+       /* enable interrupt */
+       i2c_writel(priv, OFFSET_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, OFFSET_TRANSFER_LEN, msgs->len);
+               i2c_writel(priv, OFFSET_TRANSFER_LEN_AUX,
+                          (msgs + 1)->len);
+               i2c_writel(priv, OFFSET_TRANSAC_LEN, I2C_WRRD_TRANAC_VALUE);
+       } else {
+               i2c_writel(priv, OFFSET_TRANSFER_LEN, msgs->len);
+               i2c_writel(priv, OFFSET_TRANSAC_LEN, num);
+       }
+
+       /* prepare buffer data to start transfer */
+       if (priv->op == I2C_MASTER_RD) {
+               writel(I2C_DMA_INT_FLAG_NONE, priv->pdmabase +
+               OFFSET_INT_FLAG);
+               writel(I2C_DMA_CON_RX, priv->pdmabase + OFFSET_CON);
+               priv->rx_buff = (u8 *)noncached_alloc(msgs->len,
+                               ARCH_DMA_MINALIGN);
+               writel((u32)priv->rx_buff, priv->pdmabase +
+               OFFSET_RX_MEM_ADDR);
+               writel(msgs->len, priv->pdmabase + OFFSET_RX_LEN);
+       } else if (priv->op == I2C_MASTER_WR) {
+               writel(I2C_DMA_INT_FLAG_NONE, priv->pdmabase +
+                         OFFSET_INT_FLAG);
+               writel(I2C_DMA_CON_TX, priv->pdmabase + OFFSET_CON);
+               priv->tx_buff = (u8 *)noncached_alloc(msgs->len,
+                               ARCH_DMA_MINALIGN);
+               memcpy(priv->tx_buff, msgs->buf, msgs->len);
+               writel((u32)priv->tx_buff, priv->pdmabase +
+                         OFFSET_TX_MEM_ADDR);
+               writel(msgs->len, priv->pdmabase + OFFSET_TX_LEN);
+       } else {
+               writel(I2C_DMA_CLR_FLAG, priv->pdmabase +
+                       OFFSET_INT_FLAG);
+               writel(I2C_DMA_CLR_FLAG, priv->pdmabase + OFFSET_CON);
+               priv->tx_buff = (u8 *)noncached_alloc(msgs->len,
+                               ARCH_DMA_MINALIGN);
+               priv->rx_buff = (u8 *)noncached_alloc((msgs + 1)->len,
+                               ARCH_DMA_MINALIGN);
+               memcpy(priv->tx_buff, msgs->buf, msgs->len);
+               writel((u32)priv->tx_buff, priv->pdmabase +
+                         OFFSET_TX_MEM_ADDR);
+               writel((u32)priv->rx_buff, priv->pdmabase +
+                         OFFSET_RX_MEM_ADDR);
+               writel(msgs->len, priv->pdmabase + OFFSET_TX_LEN);
+               writel((msgs + 1)->len, priv->pdmabase +
+                         OFFSET_RX_LEN);
+       }
+       writel(I2C_DMA_START_EN, priv->pdmabase + OFFSET_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, OFFSET_START, start_reg);
+
+       for (;;) {
+               irq_stat = i2c_readl(priv, OFFSET_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 + OFFSET_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, OFFSET_INTR_MASK, ~(restart_flag | I2C_HS_NACKERR |
+                 I2C_ACKERR | I2C_TRANSAC_COMP));
+
+       if (!tmo && trans_error == 0) {
+               /* transfer success ,we need to get data from fifo */
+               if (priv->op == I2C_MASTER_RD || priv->op == I2C_MASTER_WRRD) {
+                       ptr = priv->op == I2C_MASTER_RD ?
+                                       msgs->buf : (msgs + 1)->buf;
+                       data_size = priv->op == I2C_MASTER_RD ?
+                                       msgs->len : (msgs + 1)->len;
+                       memcpy(ptr, priv->rx_buff, data_size);
+               }
+       } else {
+               /* timeout or ACKERR */
+               if (tmo) {
+                       ret = -ETIMEDOUT;
+                       if (!priv->filter_msg)
+                               debug("transfer timeout! addr: 0x%x,\n",
+                                     msgs->addr);
+               } else {
+                       ret = -ENXIO;
+                       if (!priv->filter_msg)
+                               debug("ACKERR! addr: 0x%x,IRQ:0x%x\n",
+                                     msgs->addr, irq_stat);
+               }
+               mtk_i2c_init_hw(priv);
+               return ret;
+       }
+       return 0;
+}
+
+static int mtk_i2c_transfer(struct udevice *dev, struct i2c_msg *msg,
+                           int nmsgs)
+{
+       int ret;
+       int left_num;
+       u8 num_cnt;
+       struct mtk_i2c_priv *priv = dev_get_priv(dev);
+
+       priv->auto_restart = true;
+       left_num = nmsgs;
+       mtk_i2c_clk_enable(priv);
+       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;
+               }
+       }
+
+       /* checking 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--) {
+               /*priv->zero_len = true
+                *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 = I2C_OK;
+
+err_exit:
+       mtk_i2c_clk_disable(priv);
+       return ret;
+}
+
+static int mtk_i2c_ofdata_to_platdata(struct udevice *dev)
+{
+       int ret;
+       struct mtk_i2c_priv *priv = dev_get_priv(dev);
+
+       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 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);
+       mtk_i2c_clk_enable(priv);
+       mtk_i2c_init_hw(priv);
+       mtk_i2c_clk_disable(priv);
+       return 0;
+}
+
+static int mtk_i2c_deblock(struct udevice *dev)
+{
+       struct mtk_i2c_priv *priv = dev_get_priv(dev);
+
+       mtk_i2c_clk_enable(priv);
+       mtk_i2c_init_hw(priv);
+       mtk_i2c_clk_disable(priv);
+       return 0;
+}
+
+static const struct mtk_i2c_soc_data mt8518_soc_data = {
+       .dma_sync = 0,
+};
+
+static const struct mtk_i2c_soc_data mt8512_soc_data = {
+       .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,mt8518-i2c",
+               .data = (ulong)&mt8518_soc_data,
+       },
+       {
+               .compatible = "mediatek,mt8512-i2c",
+               .data = (ulong)&mt8512_soc_data,
+       },
+       {
+       }
+};
+
+U_BOOT_DRIVER(mtk_i2c) = {
+       .name           = "mtk_i2c",
+       .id             = UCLASS_I2C,
+       .of_match       = mtk_i2c_ids,
+       .ofdata_to_platdata = mtk_i2c_ofdata_to_platdata,
+       .probe          = mtk_i2c_probe,
+       .priv_auto_alloc_size = sizeof(struct mtk_i2c_priv),
+       .ops            = &mtk_i2c_ops,
+};
-- 
2.18.0

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