[PATCH v2 1/5] i2c: mediatek: add basic driver support
Mingming Lee
mingming.lee at mediatek.com
Sat Oct 10 04:23:16 CEST 2020
hi Simon,
Thank you for your carefully reveiw, and I think I would modify all of
them in next version.
On Mon, 2020-10-05 at 18:02 -0600, Simon Glass wrote:
> Hi Mingming,
>
> On Wed, 30 Sep 2020 at 02:22, mingming lee <mingming.lee at mediatek.com> wrote:
> >
> > From: Mingming Lee <Mingming.Lee at mediatek.com>
> >
> > Add MediaTek I2C basic driver
> >
> > Signed-off-by: Mingming Lee <Mingming.Lee at 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
>
> This looks good to me. Some nits below.
>
> >
> > 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
>
> Not needed
I would remove it.
>
> > + 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.Lee at mediatek.com>
> > + */
> > +
> > +#include <asm/cache.h>
> > +#include <asm/io.h>
>
> Check the include-file ordering here:
>
> https://www.denx.de/wiki/U-Boot/CodingStyle
>
I would modify the order.
> > +#include <common.h>
> > +#include <clk.h>
> > +#include <dm.h>
> > +#include <i2c.h>
> > +#include <linux/delay.h>
> > +#include <linux/errno.h>
> > +
> > +#define I2C_OK 0
>
> Drop this and just use 0
>
I would drop this.
> > +
> > +#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
>
> Can you use lower-case hex?
>
I would modify it.
> > +#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,
>
> Perhaps REG instead of OFFSET since it is shorter?
>
> > + 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;
>
> Please add comments where they are currently missing.
>
> > +};
> > +
> > +static inline void i2c_writel(struct mtk_i2c_priv *priv, u8 offset, u32 value)
>
> uint for args. There is no point in using u8, etc. and it just
> potentially increases code size. Please fix globally
>
It is better to use uint and I would modify them to uint.
> > +{
> > + 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);
>
> Error check.
I would add error check.
>
> > + 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);
>
> Error checks.
>
> These two functions should return error codes.
>
> > +}
> > +
> > +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)
>
> function comment
>
I would add function comment.
> > +{
> > + 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;
>
> uint?
>
> I don't see why these need to be u32. Please fix globally
>
I would modify it to uint.
> > +
> > + 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;
>
> blank line before final return (please fix globally)
>
I would modify it.
> > + 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)
>
> comment
>
I would add function comment.
> > +{
> > + 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);
>
> Do you need the cast?
yes,noncached_alloc() returns uinit and priv->tx_buff is u8 *,
if do not using cast, it would have warning -Wint-conversion.
>
> > + 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;
>
> Should that be REMOTEIO? Up to you.
>
I would modify it to EREMOTEIO.
> > + 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;
>
> uint (please fix globally)
I would fixed this globally.
>
> > + struct mtk_i2c_priv *priv = dev_get_priv(dev);
> > +
> > + priv->auto_restart = true;
> > + left_num = nmsgs;
> > + mtk_i2c_clk_enable(priv);
>
> error check
I would do error check globally.
>
> > + 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 */
>
> check
>
I would modify this.
> > + 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
>
> What is that comment for?
This is for debug before and I would drop it.
>
> > + *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;
>
> ret = 0
>
> > +
> > +err_exit:
> > + mtk_i2c_clk_disable(priv);
>
> error check
>
> > + 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;
>
> consider log_ret()ret or log_msg_ret(ret)
>
I would modify it.
> > +
> > + 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,
> > + },
> > + {
>
> Put the above { on the line above
>
I would modify it.
> > + .compatible = "mediatek,mt8512-i2c",
> > + .data = (ulong)&mt8512_soc_data,
> > + },
> > + {
> > + }
>
> same here
>
> > +};
> > +
> > +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
>
> Regards,
> SImon
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