[PATCH 17/31] i2c: add support for MediaTek I2C interface
Weijie Gao
weijie.gao at mediatek.com
Fri Aug 12 11:46:36 CEST 2022
On Wed, 2022-08-10 at 13:24 +0200, Michael Nazzareno Trimarchi wrote:
> Hi
>
> On Thu, Aug 4, 2022 at 5:38 AM Weijie Gao <weijie.gao at mediatek.com>
> wrote:
> >
> > This patch adds support for MediaTek I2C interface
> >
> > Signed-off-by: Weijie Gao <weijie.gao at 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.Lee at 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);
>
> I think you can use a switch. Clear can be moved out. You can use a
> bit more smarter direction flag
> in order to flush dcache when needed etc. Your code will be less
> duplicate and will be much clean
>
> Michael
OK. I'll reorganize this part.
>
> > + /* 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;
> > + }
>
> I think we have already better function to wait a condition in uboot
I didn't find such a function that can handle this complex condition.
wait_for_bit_xx can only wait for bits set unconditionally.
>
> > + }
> > +
> > + /* 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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