Re: [PATCH v5 2/2] i2c: aspeed: support ast2600 i2cv2 new register mode driver

From: Krzysztof Kozlowski
Date: Mon Feb 20 2023 - 03:43:55 EST


On 20/02/2023 07:17, Ryan Chen wrote:
> Add i2cv2 new register mode driver to support AST2600 i2c new register
> mode. AST2600 i2c controller have legacy and new register mode. The
> new register mode have global register support 4 base clock for scl
> clock selection, and new clock divider mode. The i2c new register mode
> have separate register set to control i2c master and slave.
>
> Signed-off-by: Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>
> ---
> MAINTAINERS | 9 +
> drivers/i2c/busses/Kconfig | 11 +
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-ast2600.c | 1703 ++++++++++++++++++++++++++++++
> 4 files changed, 1724 insertions(+)
> create mode 100644 drivers/i2c/busses/i2c-ast2600.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 749710e22b4d..c9841568cb24 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1924,6 +1924,15 @@ F: Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2400-i2c-ic.
> F: drivers/i2c/busses/i2c-aspeed.c
> F: drivers/irqchip/irq-aspeed-i2c-ic.c
>
> +ARM/ASPEED I2CV2 DRIVER
> +M: Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>
> +R: Andrew Jeffery <andrew@xxxxxxxx>
> +L: linux-i2c@xxxxxxxxxxxxxxx
> +L: openbmc@xxxxxxxxxxxxxxxx (moderated for non-subscribers)
> +S: Maintained
> +F: Documentation/devicetree/bindings/i2c/aspeed,i2cv2.yaml
> +F: drivers/i2c/busses/i2c-ast2600.c
> +
> ARM/ASPEED MACHINE SUPPORT
> M: Joel Stanley <joel@xxxxxxxxx>
> R: Andrew Jeffery <andrew@xxxxxxxx>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 7284206b278b..f3f7500ce768 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -389,6 +389,17 @@ config I2C_ALTERA
> This driver can also be built as a module. If so, the module
> will be called i2c-altera.
>
> +config I2C_AST2600
> + tristate "Aspeed I2C v2 Controller"
> + depends on ARCH_ASPEED || COMPILE_TEST
> + select I2C_SMBUS
> + help
> + If you say yes to this option, support will be included for the
> + Aspeed I2C controller with new register set.
> +
> + This driver can also be built as a module. If so, the module
> + will be called i2c-new-aspeed.
> +
> config I2C_ASPEED
> tristate "Aspeed I2C Controller"
> depends on ARCH_ASPEED || COMPILE_TEST
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index c5cac15f075c..d0ab4d45781c 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -38,6 +38,7 @@ obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o
> obj-$(CONFIG_I2C_ALTERA) += i2c-altera.o
> obj-$(CONFIG_I2C_AMD_MP2) += i2c-amd-mp2-pci.o i2c-amd-mp2-plat.o
> obj-$(CONFIG_I2C_ASPEED) += i2c-aspeed.o
> +obj-$(CONFIG_I2C_AST2600) += i2c-ast2600.o
> obj-$(CONFIG_I2C_AT91) += i2c-at91.o
> i2c-at91-objs := i2c-at91-core.o i2c-at91-master.o
> ifeq ($(CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL),y)
> diff --git a/drivers/i2c/busses/i2c-ast2600.c b/drivers/i2c/busses/i2c-ast2600.c
> new file mode 100644
> index 000000000000..b5fe0af57d11
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-ast2600.c
> @@ -0,0 +1,1703 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * ASPEED AST2600 new register set I2C controller driver
> + *
> + * Copyright (C) ASPEED Technology Inc.
> + */
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include <linux/reset.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/completion.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
> +#include <linux/of_device.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/i2c-smbus.h>
> +
> +/*
> + * APB clk : 100Mhz
> + * div : scl : baseclk [APB/((div/2) + 1)] : tBuf [1/bclk * 16]
> + * I2CG10[31:24] base clk4 for i2c auto recovery timeout counter (0xC6)
> + * I2CG10[23:16] base clk3 for Standard-mode (100Khz) min tBuf 4.7us
> + * 0x3c : 100.8Khz : 3.225Mhz : 4.96us
> + * 0x3d : 99.2Khz : 3.174Mhz : 5.04us
> + * 0x3e : 97.65Khz : 3.125Mhz : 5.12us
> + * 0x40 : 97.75Khz : 3.03Mhz : 5.28us
> + * 0x41 : 99.5Khz : 2.98Mhz : 5.36us (default)
> + * I2CG10[15:8] base clk2 for Fast-mode (400Khz) min tBuf 1.3us
> + * 0x12 : 400Khz : 10Mhz : 1.6us
> + * I2CG10[7:0] base clk1 for Fast-mode Plus (1Mhz) min tBuf 0.5us
> + * 0x08 : 1Mhz : 20Mhz : 0.8us
> + */
> +#define AST2600_I2CG_ISR 0x00
> +#define AST2600_I2CG_SLAVE_ISR 0x04
> +#define AST2600_I2CG_OWNER 0x08
> +#define AST2600_I2CG_CTRL 0x0C
> +#define AST2600_I2CG_CLK_DIV_CTRL 0x10
> +
> +#define AST2600_I2CG_SLAVE_PKT_NAK BIT(4)
> +#define AST2600_I2CG_M_S_SEPARATE_INTR BIT(3)
> +#define AST2600_I2CG_CTRL_NEW_REG BIT(2)
> +#define AST2600_I2CG_CTRL_NEW_CLK_DIV BIT(1)
> +
> +#define AST2600_GLOBAL_INIT \
> + (AST2600_I2CG_CTRL_NEW_REG | \
> + AST2600_I2CG_CTRL_NEW_CLK_DIV)
> +#define I2CCG_DIV_CTRL 0xC6411208
> +
> +/* 0x00 : I2CC Master/Slave Function Control Register */
> +#define AST2600_I2CC_FUN_CTRL 0x00
> +#define AST2600_I2CC_SLAVE_ADDR_RX_EN BIT(20)
> +#define AST2600_I2CC_MASTER_RETRY_MASK GENMASK(19, 18)
> +#define AST2600_I2CC_MASTER_RETRY(x) (((x) & GENMASK(1, 0)) << 18)
> +#define AST2600_I2CC_BUS_AUTO_RELEASE BIT(17)
> +#define AST2600_I2CC_M_SDA_LOCK_EN BIT(16)
> +#define AST2600_I2CC_MULTI_MASTER_DIS BIT(15)
> +#define AST2600_I2CC_M_SCL_DRIVE_EN BIT(14)
> +#define AST2600_I2CC_MSB_STS BIT(9)
> +#define AST2600_I2CC_SDA_DRIVE_1T_EN BIT(8)
> +#define AST2600_I2CC_M_SDA_DRIVE_1T_EN BIT(7)
> +#define AST2600_I2CC_M_HIGH_SPEED_EN BIT(6)
> +/* reserver 5 : 2 */
> +#define AST2600_I2CC_SLAVE_EN BIT(1)
> +#define AST2600_I2CC_MASTER_EN BIT(0)
> +
> +/* 0x04 : I2CC Master/Slave Clock and AC Timing Control Register #1 */
> +#define AST2600_I2CC_AC_TIMING 0x04
> +#define AST2600_I2CC_TTIMEOUT(x) (((x) & GENMASK(4, 0)) << 24)
> +#define AST2600_I2CC_TCKHIGHMIN(x) (((x) & GENMASK(3, 0)) << 20)
> +#define AST2600_I2CC_TCKHIGH(x) (((x) & GENMASK(3, 0)) << 16)
> +#define AST2600_I2CC_TCKLOW(x) (((x) & GENMASK(3, 0)) << 12)
> +#define AST2600_I2CC_THDDAT(x) (((x) & GENMASK(1, 0)) << 10)
> +#define AST2600_I2CC_TOUTBASECLK(x) (((x) & GENMASK(1, 0)) << 8)
> +#define AST2600_I2CC_TBASECLK(x) ((x) & GENMASK(3, 0))
> +
> +/* 0x08 : I2CC Master/Slave Transmit/Receive Byte Buffer Register */
> +#define AST2600_I2CC_STS_AND_BUFF 0x08
> +#define AST2600_I2CC_TX_DIR_MASK GENMASK(31, 29)
> +#define AST2600_I2CC_SDA_OE BIT(28)
> +#define AST2600_I2CC_SDA_O BIT(27)
> +#define AST2600_I2CC_SCL_OE BIT(26)
> +#define AST2600_I2CC_SCL_O BIT(25)
> +
> +#define AST2600_I2CC_SCL_LINE_STS BIT(18)
> +#define AST2600_I2CC_SDA_LINE_STS BIT(17)
> +#define AST2600_I2CC_BUS_BUSY_STS BIT(16)
> +
> +#define AST2600_I2CC_GET_RX_BUFF(x) (((x) >> 8) & GENMASK(7, 0))
> +
> +/* 0x0C : I2CC Master/Slave Pool Buffer Control Register */
> +#define AST2600_I2CC_BUFF_CTRL 0x0C
> +#define AST2600_I2CC_GET_RX_BUF_LEN(x) (((x) >> 24) & GENMASK(5, 0))
> +#define AST2600_I2CC_SET_RX_BUF_LEN(x) (((((x) - 1) & GENMASK(4, 0)) << 16) | BIT(0))
> +#define AST2600_I2CC_SET_TX_BUF_LEN(x) (((((x) - 1) & GENMASK(4, 0)) << 8) | BIT(0))
> +#define AST2600_I2CC_GET_TX_BUF_LEN(x) ((((x) >> 8) & GENMASK(4, 0)) + 1)
> +
> +/* 0x10 : I2CM Master Interrupt Control Register */
> +#define AST2600_I2CM_IER 0x10
> +/* 0x14 : I2CM Master Interrupt Status Register : WC */
> +#define AST2600_I2CM_ISR 0x14
> +
> +#define AST2600_I2CM_PKT_TIMEOUT BIT(18)
> +#define AST2600_I2CM_PKT_ERROR BIT(17)
> +#define AST2600_I2CM_PKT_DONE BIT(16)
> +
> +#define AST2600_I2CM_BUS_RECOVER_FAIL BIT(15)
> +#define AST2600_I2CM_SDA_DL_TO BIT(14)
> +#define AST2600_I2CM_BUS_RECOVER BIT(13)
> +#define AST2600_I2CM_SMBUS_ALT BIT(12)
> +
> +#define AST2600_I2CM_SCL_LOW_TO BIT(6)
> +#define AST2600_I2CM_ABNORMAL BIT(5)
> +#define AST2600_I2CM_NORMAL_STOP BIT(4)
> +#define AST2600_I2CM_ARBIT_LOSS BIT(3)
> +#define AST2600_I2CM_RX_DONE BIT(2)
> +#define AST2600_I2CM_TX_NAK BIT(1)
> +#define AST2600_I2CM_TX_ACK BIT(0)
> +
> +/* 0x18 : I2CM Master Command/Status Register */
> +#define AST2600_I2CM_CMD_STS 0x18
> +#define AST2600_I2CM_PKT_ADDR(x) (((x) & GENMASK(6, 0)) << 24)
> +#define AST2600_I2CM_PKT_EN BIT(16)
> +#define AST2600_I2CM_SDA_OE_OUT_DIR BIT(15)
> +#define AST2600_I2CM_SDA_O_OUT_DIR BIT(14)
> +#define AST2600_I2CM_SCL_OE_OUT_DIR BIT(13)
> +#define AST2600_I2CM_SCL_O_OUT_DIR BIT(12)
> +#define AST2600_I2CM_RECOVER_CMD_EN BIT(11)
> +
> +#define AST2600_I2CM_RX_DMA_EN BIT(9)
> +#define AST2600_I2CM_TX_DMA_EN BIT(8)
> +/* Command Bit */
> +#define AST2600_I2CM_RX_BUFF_EN BIT(7)
> +#define AST2600_I2CM_TX_BUFF_EN BIT(6)
> +#define AST2600_I2CM_STOP_CMD BIT(5)
> +#define AST2600_I2CM_RX_CMD_LAST BIT(4)
> +#define AST2600_I2CM_RX_CMD BIT(3)
> +
> +#define AST2600_I2CM_TX_CMD BIT(1)
> +#define AST2600_I2CM_START_CMD BIT(0)
> +
> +/* 0x1C : I2CM Master DMA Transfer Length Register */
> +#define AST2600_I2CM_DMA_LEN 0x1C
> +/* Tx Rx support length 1 ~ 4096 */
> +#define AST2600_I2CM_SET_RX_DMA_LEN(x) ((((x) & GENMASK(11, 0)) << 16) | BIT(31))
> +#define AST2600_I2CM_SET_TX_DMA_LEN(x) (((x) & GENMASK(11, 0)) | BIT(15))
> +
> +/* 0x20 : I2CS Slave Interrupt Control Register */
> +#define AST2600_I2CS_IER 0x20
> +/* 0x24 : I2CS Slave Interrupt Status Register */
> +#define AST2600_I2CS_ISR 0x24
> +
> +#define AST2600_I2CS_ADDR_INDICATE_MASK GENMASK(31, 30)
> +#define AST2600_I2CS_SLAVE_PENDING BIT(29)
> +
> +#define AST2600_I2CS_WAIT_TX_DMA BIT(25)
> +#define AST2600_I2CS_WAIT_RX_DMA BIT(24)
> +
> +#define AST2600_I2CS_ADDR3_NAK BIT(22)
> +#define AST2600_I2CS_ADDR2_NAK BIT(21)
> +#define AST2600_I2CS_ADDR1_NAK BIT(20)
> +
> +#define AST2600_I2CS_ADDR_MASK GENMASK(19, 18)
> +#define AST2600_I2CS_PKT_ERROR BIT(17)
> +#define AST2600_I2CS_PKT_DONE BIT(16)
> +#define AST2600_I2CS_INACTIVE_TO BIT(15)
> +
> +#define AST2600_I2CS_SLAVE_MATCH BIT(7)
> +#define AST2600_I2CS_ABNOR_STOP BIT(5)
> +#define AST2600_I2CS_STOP BIT(4)
> +#define AST2600_I2CS_RX_DONE_NAK BIT(3)
> +#define AST2600_I2CS_RX_DONE BIT(2)
> +#define AST2600_I2CS_TX_NAK BIT(1)
> +#define AST2600_I2CS_TX_ACK BIT(0)
> +
> +/* 0x28 : I2CS Slave CMD/Status Register */
> +#define AST2600_I2CS_CMD_STS 0x28
> +#define AST2600_I2CS_ACTIVE_ALL GENMASK(18, 17)
> +#define AST2600_I2CS_PKT_MODE_EN BIT(16)
> +#define AST2600_I2CS_AUTO_NAK_NOADDR BIT(15)
> +#define AST2600_I2CS_AUTO_NAK_EN BIT(14)
> +
> +#define AST2600_I2CS_ALT_EN BIT(10)
> +#define AST2600_I2CS_RX_DMA_EN BIT(9)
> +#define AST2600_I2CS_TX_DMA_EN BIT(8)
> +#define AST2600_I2CS_RX_BUFF_EN BIT(7)
> +#define AST2600_I2CS_TX_BUFF_EN BIT(6)
> +#define AST2600_I2CS_RX_CMD_LAST BIT(4)
> +
> +#define AST2600_I2CS_TX_CMD BIT(2)
> +
> +#define AST2600_I2CS_DMA_LEN 0x2C
> +#define AST2600_I2CS_SET_RX_DMA_LEN(x) (((((x) - 1) & GENMASK(11, 0)) << 16) | BIT(31))
> +#define AST2600_I2CS_RX_DMA_LEN_MASK (GENMASK(11, 0) << 16)
> +
> +#define AST2600_I2CS_SET_TX_DMA_LEN(x) ((((x) - 1) & GENMASK(11, 0)) | BIT(15))
> +#define AST2600_I2CS_TX_DMA_LEN_MASK GENMASK(11, 0)
> +
> +/* I2CM Master DMA Tx Buffer Register */
> +#define AST2600_I2CM_TX_DMA 0x30
> +/* I2CM Master DMA Rx Buffer Register */
> +#define AST2600_I2CM_RX_DMA 0x34
> +/* I2CS Slave DMA Tx Buffer Register */
> +#define AST2600_I2CS_TX_DMA 0x38
> +/* I2CS Slave DMA Rx Buffer Register */
> +#define AST2600_I2CS_RX_DMA 0x3C
> +
> +#define AST2600_I2CS_ADDR_CTRL 0x40
> +
> +#define AST2600_I2CS_ADDR3_MASK GENMASK(22, 16)
> +#define AST2600_I2CS_ADDR2_MASK GENMASK(14, 8)
> +#define AST2600_I2CS_ADDR1_MASK GENMASK(6, 0)

Drop indent after #define

> +
> +#define AST2600_I2CM_DMA_LEN_STS 0x48
> +#define AST2600_I2CS_DMA_LEN_STS 0x4C
> +
> +#define AST2600_I2C_GET_TX_DMA_LEN(x) ((x) & GENMASK(12, 0))
> +#define AST2600_I2C_GET_RX_DMA_LEN(x) (((x) >> 16) & GENMASK(12, 0))
> +
> +/* 0x40 : Slave Device Address Register */
> +#define AST2600_I2CS_ADDR3_ENABLE BIT(23)
> +#define AST2600_I2CS_ADDR3(x) ((x) << 16)
> +
> +#define AST2600_I2CS_ADDR2_ENABLE BIT(15)
> +#define AST2600_I2CS_ADDR2(x) ((x) << 8)
> +#define AST2600_I2CS_ADDR1_ENABLE BIT(7)
> +#define AST2600_I2CS_ADDR1(x) (x)
> +
> +#define I2C_SLAVE_MSG_BUF_SIZE 256
> +
> +#define AST2600_I2C_DMA_SIZE 4096
> +
> +#define MASTER_TRIGGER_LAST_STOP (AST2600_I2CM_RX_CMD_LAST | AST2600_I2CM_STOP_CMD)
> +#define SLAVE_TRIGGER_CMD (AST2600_I2CS_ACTIVE_ALL | AST2600_I2CS_PKT_MODE_EN)
> +
> +/* i2c timeout counter: use base clk4 1Mhz
> + * 1/(1000/4096) = 4.096ms * 8 = 32.768ms
> + */
> +#define AST_I2C_TIMEOUT_CLK 0x2
> +#define AST_I2C_TIMEOUT_COUNT 0x8
> +
> +struct ast2600_i2c_timing_table {
> + u32 divisor;
> + u32 timing;
> +};
> +
> +enum xfer_mode {
> + BYTE_MODE = 0,
> + BUFF_MODE,
> + DMA_MODE,
> +};
> +
> +struct ast2600_i2c_bus {
> + struct i2c_adapter adap;
> + struct device *dev;
> + void __iomem *reg_base;
> + struct regmap *gr_regmap;
> + struct reset_control *rst;
> + int irq;
> + enum xfer_mode mode;
> + struct clk *clk;
> + u32 apb_clk;
> + u32 bus_frequency;
> + int slave_operate;
> + int timeout_enable;
> + /* smbus alert */
> + int alert_enable;
> + struct i2c_smbus_alert_setup alert_data;
> + struct i2c_client *ara;
> + /* Multi-master */
> + bool multi_master;
> + /* master structure */
> + int cmd_err;
> + struct completion cmd_complete;
> + struct i2c_msg *msgs;
> + size_t buf_index;
> + /* cur xfer msgs index*/
> + int msgs_index;
> + int msgs_count;
> + u8 *master_safe_buf;
> + dma_addr_t master_dma_addr;
> + /*total xfer count */
> + int master_xfer_cnt;
> + /* Buffer mode */
> + void __iomem *buf_base;
> + size_t buf_size;
> + /* Slave structure */
> + int slave_xfer_len;
> + int slave_xfer_cnt;
> +#ifdef CONFIG_I2C_SLAVE
> + unsigned char *slave_dma_buf;
> + dma_addr_t slave_dma_addr;
> + struct i2c_client *slave;
> +#endif
> +};
> +

(...)

> +
> + //Check 0x14's SDA and SCL status

Use Linux coding style. See Coding style document.

> + state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
> + if (!(state & AST2600_I2CC_SDA_LINE_STS) && (state & AST2600_I2CC_SCL_LINE_STS)) {
> + writel(AST2600_I2CM_RECOVER_CMD_EN, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
> + r = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
> + if (r == 0) {
> + dev_dbg(i2c_bus->dev, "recovery timed out\n");
> + ret = -ETIMEDOUT;
> + } else {
> + if (i2c_bus->cmd_err) {
> + dev_dbg(i2c_bus->dev, "recovery error\n");
> + ret = -EPROTO;
> + }
> + }
> + }
> +
> + dev_dbg(i2c_bus->dev, "Recovery done [%x]\n",
> + readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
> + if (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) & AST2600_I2CC_BUS_BUSY_STS) {
> + dev_dbg(i2c_bus->dev, "Can't recovery bus [%x]\n",
> + readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
> + }
> +
> + writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> + return ret;
> +}
> +
> +#ifdef CONFIG_I2C_SLAVE
> +static void ast2600_i2c_slave_packet_dma_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
> +{
> + int slave_rx_len;
> + u32 cmd = 0;
> + u8 value;
> + int i = 0;
> +
> + sts &= ~(AST2600_I2CS_SLAVE_PENDING);
> + /* Handle i2c slave timeout condition */
> + if (AST2600_I2CS_INACTIVE_TO & sts) {
> + cmd = SLAVE_TRIGGER_CMD;
> + cmd |= AST2600_I2CS_RX_DMA_EN;
> + writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> + writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> + return;
> + }
> +
> + sts &= ~(AST2600_I2CS_PKT_DONE | AST2600_I2CS_PKT_ERROR);
> +
> + switch (sts) {
> + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
> + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_RX_DMA:
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_REQUESTED, &value);
> + slave_rx_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
> + AST2600_I2CS_DMA_LEN_STS));
> + for (i = 0; i < slave_rx_len; i++) {
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_RECEIVED,
> + &i2c_bus->slave_dma_buf[i]);
> + }
> + writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
> + break;
> + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_STOP:
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> + writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
> + break;
> + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE_NAK |
> + AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
> + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_RX_DMA |
> + AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
> + case AST2600_I2CS_RX_DONE_NAK | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
> + case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_STOP:
> + case AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
> + case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
> + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
> + if (sts & AST2600_I2CS_SLAVE_MATCH)
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_REQUESTED, &value);
> +
> + slave_rx_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
> + AST2600_I2CS_DMA_LEN_STS));
> + for (i = 0; i < slave_rx_len; i++) {
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_RECEIVED,
> + &i2c_bus->slave_dma_buf[i]);
> + }
> + writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> + if (sts & AST2600_I2CS_STOP)
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
> + break;
> +
> + /* it is Mw data Mr coming -> it need send tx */
> + case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_TX_DMA:
> + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_TX_DMA:
> + /* it should be repeat start read */
> + if (sts & AST2600_I2CS_SLAVE_MATCH)
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_REQUESTED, &value);
> +
> + slave_rx_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
> + AST2600_I2CS_DMA_LEN_STS));
> + for (i = 0; i < slave_rx_len; i++) {
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_RECEIVED,
> + &i2c_bus->slave_dma_buf[i]);
> + }
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_READ_REQUESTED,
> + &i2c_bus->slave_dma_buf[0]);
> + writel(0, i2c_bus->reg_base + AST2600_I2CS_DMA_LEN_STS);
> + writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
> + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
> + break;
> + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_TX_DMA:
> + /* First Start read */
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_READ_REQUESTED,
> + &i2c_bus->slave_dma_buf[0]);
> + writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
> + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
> + break;
> + case AST2600_I2CS_WAIT_TX_DMA:
> + /* it should be next start read */
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_READ_PROCESSED,
> + &i2c_bus->slave_dma_buf[0]);
> + writel(0, i2c_bus->reg_base + AST2600_I2CS_DMA_LEN_STS);
> + writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
> + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
> + break;
> +
> + case AST2600_I2CS_TX_NAK | AST2600_I2CS_STOP:
> + /* it just tx complete */
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> + writel(0, i2c_bus->reg_base + AST2600_I2CS_DMA_LEN_STS);
> + writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_SLAVE_MSG_BUF_SIZE),
> + i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
> + cmd = SLAVE_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
> + break;
> + case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
> + cmd = 0;
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_WRITE_REQUESTED, &value);
> + break;
> + case AST2600_I2CS_STOP:
> + cmd = 0;
> + i2c_slave_event(i2c_bus->slave, I2C_SLAVE_STOP, &value);
> + break;
> + default:
> + dev_dbg(i2c_bus->dev, "todo slave isr case %x, sts %x\n", sts,
> + readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
> + break;
> + }
> +
> + if (cmd)
> + writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
> + writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
> + readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
> + dev_dbg(i2c_bus->dev, "cmd %x\n", cmd);
> +}
> +
> +static void ast2600_i2c_slave_packet_buff_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
> +{
> + int slave_rx_len = 0;
> + u32 cmd = 0;
> + u8 value;
> + int i = 0;
> +
> + //due to master slave is common buffer, so need force the master stop not issue

Ditto... and everywhere else.

(...)

> +
> +static int ast2600_i2c_master_irq(struct ast2600_i2c_bus *i2c_bus)
> +{
> + u32 sts = readl(i2c_bus->reg_base + AST2600_I2CM_ISR);
> + u32 ier = readl(i2c_bus->reg_base + AST2600_I2CM_IER);
> + u32 ctrl = 0;
> +
> + dev_dbg(i2c_bus->dev, "M sts %x\n", sts);

NAK. Don't drop debugs to interrupt handlers. This might flood the log
and is unusable.

> + if (!i2c_bus->alert_enable)
> + sts &= ~AST2600_I2CM_SMBUS_ALT;
> +
> + if (AST2600_I2CM_BUS_RECOVER_FAIL & sts) {
> + dev_dbg(i2c_bus->dev, "M clear isr: AST2600_I2CM_BUS_RECOVER_FAIL= %x\n", sts);

No debugs in handlers.

> + writel(AST2600_I2CM_BUS_RECOVER_FAIL, i2c_bus->reg_base + AST2600_I2CM_ISR);
> + ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> + writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> + writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> + i2c_bus->cmd_err = -EPROTO;
> + complete(&i2c_bus->cmd_complete);
> + return 1;
> + }
> +
> + if (AST2600_I2CM_BUS_RECOVER & sts) {
> + dev_dbg(i2c_bus->dev, "M clear isr: AST2600_I2CM_BUS_RECOVER= %x\n", sts);

Ditto

> + writel(AST2600_I2CM_BUS_RECOVER, i2c_bus->reg_base + AST2600_I2CM_ISR);
> + i2c_bus->cmd_err = 0;
> + complete(&i2c_bus->cmd_complete);
> + return 1;
> + }
> +
> + if (AST2600_I2CM_SMBUS_ALT & sts) {
> + if (ier & AST2600_I2CM_SMBUS_ALT) {
> + dev_dbg(i2c_bus->dev, "M clear isr: AST2600_I2CM_SMBUS_ALT= %x\n", sts);

Ditto

> + /* Disable ALT INT */
> + writel(ier & ~AST2600_I2CM_SMBUS_ALT, i2c_bus->reg_base + AST2600_I2CM_IER);
> + i2c_handle_smbus_alert(i2c_bus->ara);
> + writel(AST2600_I2CM_SMBUS_ALT, i2c_bus->reg_base + AST2600_I2CM_ISR);
> + dev_err(i2c_bus->dev,
> + "ast2600_master_alert_recv bus id %d, Disable Alt, Please Imple\n",
> + i2c_bus->adap.nr);

Really? This is your intention? To print error on every error condition
on every interrupt?

> + return 1;
> + }
> + }
> +
> + i2c_bus->cmd_err = ast2600_i2c_is_irq_error(sts);
> + if (i2c_bus->cmd_err) {
> + dev_dbg(i2c_bus->dev, "received error interrupt: 0x%02x\n", sts);

Drop

> + writel(AST2600_I2CM_PKT_DONE, i2c_bus->reg_base + AST2600_I2CM_ISR);
> + complete(&i2c_bus->cmd_complete);
> + return 1;
> + }
> +
> + if (AST2600_I2CM_PKT_DONE & sts) {
> + ast2600_i2c_master_package_irq(i2c_bus, sts);
> + return 1;
> + }
> +
> + return 0;
> +}
> +
> +static irqreturn_t ast2600_i2c_bus_irq(int irq, void *dev_id)
> +{
> + struct ast2600_i2c_bus *i2c_bus = dev_id;
> +
> +#ifdef CONFIG_I2C_SLAVE
> + if (readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL) & AST2600_I2CC_SLAVE_EN) {
> + if (ast2600_i2c_slave_irq(i2c_bus)) {
> +// dev_dbg(i2c_bus->dev, "bus-%d.slave handle\n", i2c_bus->adap.nr);

Drop

> + return IRQ_HANDLED;
> + }
> + }
> +#endif
> + return ast2600_i2c_master_irq(i2c_bus) ? IRQ_HANDLED : IRQ_NONE;
> +}
> +

(...)

> +
> +static int ast2600_i2c_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct ast2600_i2c_bus *i2c_bus;
> + struct resource *res;
> + u32 global_ctrl;
> + int ret = 0;
> +
> + i2c_bus = devm_kzalloc(&pdev->dev, sizeof(*i2c_bus), GFP_KERNEL);
> + if (!i2c_bus)
> + return -ENOMEM;
> +
> + i2c_bus->rst = devm_reset_control_get_shared(&pdev->dev, NULL);
> + if (IS_ERR(i2c_bus->rst)) {
> + dev_err(&pdev->dev,
> + "missing or invalid reset controller device tree entry\n");
> + goto free_mem;
> + }
> + reset_control_deassert(i2c_bus->rst);
> +
> + i2c_bus->gr_regmap = syscon_regmap_lookup_by_phandle(np, "aspeed,i2c-global");

NAK, undocumented property. This is really untested patchset. Your code
does not match bindings which do not match DTS.

Send entire set - bindings, driver and DTS which all work together.

Further you have several other undocumented properties.

> + if (IS_ERR(i2c_bus->gr_regmap)) {
> + dev_err(&pdev->dev, "failed to find ast2600 i2c global regmap\n");
> + ret = -ENOMEM;
> + goto free_mem;
> + }
> +
> + regmap_read(i2c_bus->gr_regmap, AST2600_I2CG_CTRL, &global_ctrl);
> + if ((global_ctrl & AST2600_GLOBAL_INIT) != AST2600_GLOBAL_INIT) {
> + regmap_write(i2c_bus->gr_regmap, AST2600_I2CG_CTRL, AST2600_GLOBAL_INIT);
> + regmap_write(i2c_bus->gr_regmap, AST2600_I2CG_CLK_DIV_CTRL, I2CCG_DIV_CTRL);
> + }
> +
> + i2c_bus->mode = DMA_MODE;
> + i2c_bus->slave_operate = 0;
> +
> + if (of_property_read_bool(pdev->dev.of_node, "byte-mode"))

This must be gone from DT, as you do not describe hardware but "force
driver".

> + i2c_bus->mode = BYTE_MODE;> +
> + if (of_property_read_bool(pdev->dev.of_node, "buff-mode")) {

This for sure is not property of DT.

> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + if (res && resource_size(res) >= 2)
> + i2c_bus->buf_base = devm_ioremap_resource(&pdev->dev, res);
> +
> + if (!IS_ERR_OR_NULL(i2c_bus->buf_base))
> + i2c_bus->buf_size = resource_size(res)/2;
> +
> + i2c_bus->mode = BUFF_MODE;
> + }
> +
> + if (of_property_read_bool(pdev->dev.of_node, "timeout"))

Also will be gone.

> + i2c_bus->timeout_enable = 1;
> +
> + i2c_bus->dev = &pdev->dev;
> + init_completion(&i2c_bus->cmd_complete);
> +
> + i2c_bus->reg_base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(i2c_bus->reg_base)) {
> + ret = PTR_ERR(i2c_bus->reg_base);
> + goto free_mem;
> + }
> +
> + i2c_bus->irq = platform_get_irq(pdev, 0);
> + if (i2c_bus->irq < 0) {
> + dev_err(&pdev->dev, "no irq specified\n");
> + ret = -i2c_bus->irq;
> + goto unmap;
> + }
> +
> + platform_set_drvdata(pdev, i2c_bus);
> +
> + i2c_bus->clk = devm_clk_get(i2c_bus->dev, NULL);
> + if (IS_ERR(i2c_bus->clk)) {
> + dev_err(i2c_bus->dev, "no clock defined\n");

use dev_err_probe().

> + ret = -ENODEV;
> + goto unmap;
> + }
> + i2c_bus->apb_clk = clk_get_rate(i2c_bus->clk);
> + dev_dbg(i2c_bus->dev, "i2c_bus->apb_clk %d\n", i2c_bus->apb_clk);
> +

NAK, drop useless debug.

> +
> + ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency", &i2c_bus->bus_frequency);
> + if (ret < 0) {
> + dev_warn(&pdev->dev, "Could not read bus-frequency property\n");
> + i2c_bus->bus_frequency = 100000;
> + }
> +
> + /* Initialize the I2C adapter */
> + i2c_bus->adap.owner = THIS_MODULE;
> + i2c_bus->adap.algo = &i2c_ast2600_algorithm;
> + i2c_bus->adap.retries = 0;
> + i2c_bus->adap.dev.parent = i2c_bus->dev;
> + i2c_bus->adap.dev.of_node = pdev->dev.of_node;
> + i2c_bus->adap.algo_data = i2c_bus;
> + strscpy(i2c_bus->adap.name, pdev->name, sizeof(i2c_bus->adap.name));
> + i2c_set_adapdata(&i2c_bus->adap, i2c_bus);
> +
> + ast2600_i2c_init(i2c_bus);
> +
> + ret = devm_request_irq(&pdev->dev, i2c_bus->irq, ast2600_i2c_bus_irq, 0,
> + dev_name(&pdev->dev), i2c_bus);
> + if (ret < 0)
> + goto unmap;
> +
> + if (of_property_read_bool(pdev->dev.of_node, "smbus-alert")) {

There is no such property. Don't add undocumented properties to your code.

> +
> + return 0;
> +
> +free_irq:
> + devm_free_irq(&pdev->dev, i2c_bus->irq, i2c_bus);

Why?

> +unmap:
> + devm_iounmap(&pdev->dev, i2c_bus->reg_base);

Why?

> +free_mem:
> + devm_kfree(&pdev->dev, i2c_bus);

Why?

> +
> + return ret;
> +}
> +
> +static int ast2600_i2c_remove(struct platform_device *pdev)
> +{
> + struct ast2600_i2c_bus *i2c_bus = platform_get_drvdata(pdev);
> +
> + /* Disable everything. */
> + writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> + writel(0, i2c_bus->reg_base + AST2600_I2CM_IER);
> +
> + devm_free_irq(&pdev->dev, i2c_bus->irq, i2c_bus);
> +
> + i2c_del_adapter(&i2c_bus->adap);

Wrong order of cleanup. It should be reversed to the probe, unless you
have some reason, but then please explain.

> +
> +#ifdef CONFIG_I2C_SLAVE
> + /* for memory buffer initial */
> + if (i2c_bus->mode == DMA_MODE)
> + dma_free_coherent(i2c_bus->dev, I2C_SLAVE_MSG_BUF_SIZE,
> + i2c_bus->slave_dma_buf, i2c_bus->slave_dma_addr);
> +#endif
> +
> + return 0;
> +}
> +
> +static struct platform_driver ast2600_i2c_bus_driver = {
> + .probe = ast2600_i2c_probe,
> + .remove = ast2600_i2c_remove,
> + .driver = {
> + .name = KBUILD_MODNAME,
> + .of_match_table = ast2600_i2c_bus_of_table,
> + },
> +};
> +module_platform_driver(ast2600_i2c_bus_driver);
> +
> +MODULE_AUTHOR("Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("ASPEED AST2600 I2C Controller Driver");
> +MODULE_LICENSE("GPL");

Best regards,
Krzysztof