[PATCH v15 2/3] i2c: aspeed: support AST2600 i2c new register mode driver
Naresh Solanki
naresh.solanki at 9elements.com
Mon Nov 11 22:00:04 AEDT 2024
Hi Ryan,
I've tested the driver changes in my machine
based on "SOC: AST2600-A3".
I faced some issue testing the driver.
While the driver functions correctly in
Normal mode, I encountered issues when attempting
to run it in DMA and BUFF modes. Given the
instability in these modes, I suspect there may
be misconfigurations in my device tree setup.
Could you please provide a sample configuration for
the device tree that would ensure stable operation
of the driver in both DMA and BUFF modes?
Thank you for your support.
Regards,
Naresh
On 07-10-2024 09:22:34, Ryan Chen wrote:
> Add i2c 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 new register mode have separate register
> set to control i2c controller and target. This patch is for i2c
> controller mode driver.
>
> Signed-off-by: Ryan Chen <ryan_chen at aspeedtech.com>
> ---
> drivers/i2c/busses/Kconfig | 11 +
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-ast2600.c | 1032 ++++++++++++++++++++++++++++++
> 3 files changed, 1044 insertions(+)
> create mode 100644 drivers/i2c/busses/i2c-ast2600.c
>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index a22f9125322a..abfb027350d4 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -410,6 +410,17 @@ 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-ast2600.
> +
> 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 78d0561339e5..5665b60b1566 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -39,6 +39,7 @@ 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..17ba0ee77c27
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-ast2600.c
> @@ -0,0 +1,1032 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * ASPEED AST2600 new register set I2C controller driver
> + *
> + * Copyright (C) ASPEED Technology Inc.
> + */
> +#include <asm/unaligned.h>
> +#include <linux/array_size.h>
> +#include <linux/bits.h>
> +#include <linux/clk.h>
> +#include <linux/completion.h>
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/i2c-smbus.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/minmax.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +#include <linux/slab.h>
> +#include <linux/string_helpers.h>
> +
> +#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)
> +/*
> + * 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 I2CCG_DIV_CTRL 0xC6411208
> +
> +/* 0x00 : I2CC Controller/Target 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 Controller/Target 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 Controller/Target 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 Controller/Target Pool Buffer Control Register */
> +#define AST2600_I2CC_BUFF_CTRL 0x0C
> +#define AST2600_I2CC_GET_RX_BUF_LEN(x) (((x) & GENMASK(29, 24)) >> 24)
> +#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) & GENMASK(12, 8)) >> 8) + 1)
> +
> +/* 0x10 : I2CM Controller Interrupt Control Register */
> +#define AST2600_I2CM_IER 0x10
> +/* 0x14 : I2CM Controller 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 Controller 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 Controller 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 Target Interrupt Control Register */
> +#define AST2600_I2CS_IER 0x20
> +/* 0x24 : I2CS Target 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 Target 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_SET_TX_DMA_LEN(x) ((((x) - 1) & GENMASK(11, 0)) | BIT(15))
> +
> +/* I2CM Controller DMA Tx Buffer Register */
> +#define AST2600_I2CM_TX_DMA 0x30
> +/* I2CM Controller DMA Rx Buffer Register */
> +#define AST2600_I2CM_RX_DMA 0x34
> +/* I2CS Target DMA Tx Buffer Register */
> +#define AST2600_I2CS_TX_DMA 0x38
> +/* I2CS Target 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)
> +
> +#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) & GENMASK(28, 16)) >> 16)
> +
> +/* 0x40 : Target 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_TARGET_MSG_BUF_SIZE 256
> +
> +#define AST2600_I2C_DMA_SIZE 4096
> +
> +#define CONTROLLER_TRIGGER_LAST_STOP (AST2600_I2CM_RX_CMD_LAST | AST2600_I2CM_STOP_CMD)
> +#define TARGET_TRIGGER_CMD (AST2600_I2CS_ACTIVE_ALL | AST2600_I2CS_PKT_MODE_EN)
> +
> +#define AST_I2C_TIMEOUT_CLK 0x2
> +
> +enum xfer_mode {
> + BYTE_MODE,
> + BUFF_MODE,
> + DMA_MODE,
> +};
> +
> +struct ast2600_i2c_bus {
> + struct i2c_adapter adap;
> + struct device *dev;
> + void __iomem *reg_base;
> + struct regmap *global_regs;
> + struct reset_control *rst;
> + struct clk *clk;
> + struct i2c_timings timing_info;
> + struct completion cmd_complete;
> + struct i2c_msg *msgs;
> + u8 *controller_dma_safe_buf;
> + dma_addr_t controller_dma_addr;
> + u32 apb_clk;
> + u32 timeout;
> + int irq;
> + int cmd_err;
> + int msgs_index;
> + int msgs_count;
> + int controller_xfer_cnt;
> + size_t buf_index;
> + size_t buf_size;
> + enum xfer_mode mode;
> + bool multi_master;
> + /* Buffer mode */
> + void __iomem *buf_base;
> + struct i2c_smbus_alert_setup alert_data;
> +};
> +
> +static u32 ast2600_select_i2c_clock(struct ast2600_i2c_bus *i2c_bus)
> +{
> + unsigned long base_clk[16];
> + int baseclk_idx = 0;
> + int divisor = 0;
> + u32 clk_div_reg;
> + u32 scl_low;
> + u32 scl_high;
> + u32 data;
> +
> + regmap_read(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, &clk_div_reg);
> +
> + for (int i = 0; i < ARRAY_SIZE(base_clk); i++) {
> + if (i == 0)
> + base_clk[i] = i2c_bus->apb_clk;
> + else if (i < 5)
> + base_clk[i] = (i2c_bus->apb_clk * 2) /
> + (((clk_div_reg >> ((i - 1) * 8)) & GENMASK(7, 0)) + 2);
> + else
> + base_clk[i] = base_clk[4] >> (i - 5);
> +
> + if ((base_clk[i] / i2c_bus->timing_info.bus_freq_hz) <= 32) {
> + baseclk_idx = i;
> + divisor = DIV_ROUND_UP(base_clk[i], i2c_bus->timing_info.bus_freq_hz);
> + break;
> + }
> + }
> + baseclk_idx = min(baseclk_idx, 15);
> + divisor = min(divisor, 32);
> + scl_low = min(divisor * 9 / 16 - 1, 15);
> + scl_high = (divisor - scl_low - 2) & GENMASK(3, 0);
> + data = (scl_high - 1) << 20 | scl_high << 16 | scl_low << 12 | baseclk_idx;
> + if (i2c_bus->timeout) {
> + data |= AST2600_I2CC_TOUTBASECLK(AST_I2C_TIMEOUT_CLK);
> + data |= AST2600_I2CC_TTIMEOUT(i2c_bus->timeout);
> + }
> +
> + return data;
> +}
> +
> +static u8 ast2600_i2c_recover_bus(struct ast2600_i2c_bus *i2c_bus)
> +{
> + u32 state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
> + int ret = 0;
> + u32 ctrl;
> + int r;
> +
> + dev_dbg(i2c_bus->dev, "%d-bus recovery bus [%x]\n", i2c_bus->adap.nr, state);
> +
> + ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> +
> + /* Disable controller */
> + writel(ctrl & ~(AST2600_I2CC_MASTER_EN | AST2600_I2CC_SLAVE_EN),
> + i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> +
> + writel(readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL) | AST2600_I2CC_MASTER_EN,
> + i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> +
> + reinit_completion(&i2c_bus->cmd_complete);
> + i2c_bus->cmd_err = 0;
> +
> + /* Check 0x14's SDA and SCL status */
> + 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");
> + writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> + return -ETIMEDOUT;
> + } else if (i2c_bus->cmd_err) {
> + dev_dbg(i2c_bus->dev, "recovery error\n");
> + ret = -EPROTO;
> + }
> + }
> +
> + /* Recovery done */
> + state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
> + if (state & AST2600_I2CC_BUS_BUSY_STS) {
> + dev_dbg(i2c_bus->dev, "Can't recover bus [%x]\n", state);
> + ret = -EPROTO;
> + }
> +
> + /* restore original controller setting */
> + writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> + return ret;
> +}
> +
> +static int ast2600_i2c_setup_dma_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
> +{
> + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
> + int xfer_len;
> + int ret;
> +
> + cmd |= AST2600_I2CM_PKT_EN;
> + xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
> + if (xfer_len > AST2600_I2C_DMA_SIZE)
> + xfer_len = AST2600_I2C_DMA_SIZE;
> + else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
> + cmd |= AST2600_I2CM_STOP_CMD;
> +
> + if (cmd & AST2600_I2CM_START_CMD) {
> + cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
> + i2c_bus->controller_dma_safe_buf = i2c_get_dma_safe_msg_buf(msg, 1);
> + if (!i2c_bus->controller_dma_safe_buf)
> + return -ENOMEM;
> + i2c_bus->controller_dma_addr =
> + dma_map_single(i2c_bus->dev, i2c_bus->controller_dma_safe_buf,
> + msg->len, DMA_TO_DEVICE);
> + ret = dma_mapping_error(i2c_bus->dev, i2c_bus->controller_dma_addr);
> + if (ret) {
> + i2c_put_dma_safe_msg_buf(i2c_bus->controller_dma_safe_buf, msg, false);
> + i2c_bus->controller_dma_safe_buf = NULL;
> + return ret;
> + }
> + }
> +
> + if (xfer_len) {
> + cmd |= AST2600_I2CM_TX_DMA_EN | AST2600_I2CM_TX_CMD;
> + writel(AST2600_I2CM_SET_TX_DMA_LEN(xfer_len - 1),
> + i2c_bus->reg_base + AST2600_I2CM_DMA_LEN);
> + writel(i2c_bus->controller_dma_addr + i2c_bus->controller_xfer_cnt,
> + i2c_bus->reg_base + AST2600_I2CM_TX_DMA);
> + }
> +
> + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
> +
> + return 0;
> +}
> +
> +static int ast2600_i2c_setup_buff_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
> +{
> + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
> + u32 wbuf_dword;
> + int xfer_len;
> + int i;
> +
> + cmd |= AST2600_I2CM_PKT_EN;
> + xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
> + if (xfer_len > i2c_bus->buf_size)
> + xfer_len = i2c_bus->buf_size;
> + else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
> + cmd |= AST2600_I2CM_STOP_CMD;
> +
> + if (cmd & AST2600_I2CM_START_CMD)
> + cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
> +
> + if (xfer_len) {
> + cmd |= AST2600_I2CM_TX_BUFF_EN | AST2600_I2CM_TX_CMD;
> + /*
> + * The controller's buffer register supports dword writes only.
> + * Therefore, write dwords to the buffer register in a 4-byte aligned,
> + * and write the remaining unaligned data at the end.
> + */
> + for (i = 0; i < xfer_len; i += 4) {
> + int xfer_cnt = i2c_bus->controller_xfer_cnt + i;
> +
> + switch (min(xfer_len - i, 4) % 4) {
> + case 1:
> + wbuf_dword = msg->buf[xfer_cnt];
> + break;
> + case 2:
> + wbuf_dword = get_unaligned_le16(&msg->buf[xfer_cnt]);
> + break;
> + case 3:
> + wbuf_dword = get_unaligned_le24(&msg->buf[xfer_cnt]);
> + break;
> + default:
> + wbuf_dword = get_unaligned_le32(&msg->buf[xfer_cnt]);
> + break;
> + }
> + writel(wbuf_dword, i2c_bus->buf_base + i);
> + }
> + writel(AST2600_I2CC_SET_TX_BUF_LEN(xfer_len),
> + i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
> + }
> +
> + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
> +
> + return 0;
> +}
> +
> +static int ast2600_i2c_setup_byte_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
> +{
> + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
> + int xfer_len;
> +
> + xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
> +
> + cmd |= AST2600_I2CM_PKT_EN;
> +
> + if (cmd & AST2600_I2CM_START_CMD)
> + cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
> +
> + if ((i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) &&
> + ((i2c_bus->controller_xfer_cnt + 1) == msg->len))
> + cmd |= AST2600_I2CM_STOP_CMD;
> +
> + if (xfer_len) {
> + cmd |= AST2600_I2CM_TX_CMD;
> + writel(msg->buf[i2c_bus->controller_xfer_cnt],
> + i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
> + }
> +
> + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
> +
> + return 0;
> +}
> +
> +static int ast2600_i2c_setup_dma_rx(struct ast2600_i2c_bus *i2c_bus)
> +{
> + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
> + int xfer_len;
> + u32 cmd;
> + int ret;
> +
> + cmd = AST2600_I2CM_PKT_EN | AST2600_I2CM_PKT_ADDR(msg->addr) |
> + AST2600_I2CM_START_CMD | AST2600_I2CM_RX_DMA_EN;
> +
> + if (msg->flags & I2C_M_RECV_LEN) {
> + xfer_len = 1;
> + } else if (msg->len > AST2600_I2C_DMA_SIZE) {
> + xfer_len = AST2600_I2C_DMA_SIZE;
> + } else {
> + xfer_len = msg->len;
> + if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
> + cmd |= CONTROLLER_TRIGGER_LAST_STOP;
> + }
> + writel(AST2600_I2CM_SET_RX_DMA_LEN(xfer_len - 1), i2c_bus->reg_base + AST2600_I2CM_DMA_LEN);
> + i2c_bus->controller_dma_safe_buf = i2c_get_dma_safe_msg_buf(msg, 1);
> + if (!i2c_bus->controller_dma_safe_buf)
> + return -ENOMEM;
> + i2c_bus->controller_dma_addr =
> + dma_map_single(i2c_bus->dev, i2c_bus->controller_dma_safe_buf,
> + msg->len, DMA_FROM_DEVICE);
> + ret = dma_mapping_error(i2c_bus->dev, i2c_bus->controller_dma_addr);
> + if (ret) {
> + i2c_put_dma_safe_msg_buf(i2c_bus->controller_dma_safe_buf, msg, false);
> + i2c_bus->controller_dma_safe_buf = NULL;
> + return ret;
> + }
> + writel(i2c_bus->controller_dma_addr, i2c_bus->reg_base + AST2600_I2CM_RX_DMA);
> +
> + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
> +
> + return 0;
> +}
> +
> +static int ast2600_i2c_setup_buff_rx(struct ast2600_i2c_bus *i2c_bus)
> +{
> + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
> + int xfer_len;
> + u32 cmd;
> +
> + cmd = AST2600_I2CM_PKT_EN | AST2600_I2CM_PKT_ADDR(msg->addr) |
> + AST2600_I2CM_START_CMD | AST2600_I2CM_RX_BUFF_EN;
> +
> + if (msg->flags & I2C_M_RECV_LEN) {
> + dev_dbg(i2c_bus->dev, "smbus read\n");
> + xfer_len = 1;
> + } else if (msg->len > i2c_bus->buf_size) {
> + xfer_len = i2c_bus->buf_size;
> + } else {
> + xfer_len = msg->len;
> + if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
> + cmd |= CONTROLLER_TRIGGER_LAST_STOP;
> + }
> + writel(AST2600_I2CC_SET_RX_BUF_LEN(xfer_len), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
> +
> + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
> +
> + return 0;
> +}
> +
> +static int ast2600_i2c_setup_byte_rx(struct ast2600_i2c_bus *i2c_bus)
> +{
> + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
> + u32 cmd;
> +
> + cmd = AST2600_I2CM_PKT_EN | AST2600_I2CM_PKT_ADDR(msg->addr) |
> + AST2600_I2CM_START_CMD | AST2600_I2CM_RX_CMD;
> +
> + if (msg->flags & I2C_M_RECV_LEN) {
> + dev_dbg(i2c_bus->dev, "smbus read\n");
> + } else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) {
> + if (msg->len == 1)
> + cmd |= CONTROLLER_TRIGGER_LAST_STOP;
> + }
> +
> + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
> +
> + return 0;
> +}
> +
> +static int ast2600_i2c_do_start(struct ast2600_i2c_bus *i2c_bus)
> +{
> + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
> +
> + /* send start */
> + dev_dbg(i2c_bus->dev, "[%d] %s %d byte%s %s 0x%02x\n",
> + i2c_bus->msgs_index, str_read_write(msg->flags & I2C_M_RD),
> + msg->len, str_plural(msg->len),
> + msg->flags & I2C_M_RD ? "from" : "to", msg->addr);
> +
> + i2c_bus->controller_xfer_cnt = 0;
> + i2c_bus->buf_index = 0;
> +
> + if (msg->flags & I2C_M_RD) {
> + if (i2c_bus->mode == DMA_MODE)
> + return ast2600_i2c_setup_dma_rx(i2c_bus);
> + else if (i2c_bus->mode == BUFF_MODE)
> + return ast2600_i2c_setup_buff_rx(i2c_bus);
> + else
> + return ast2600_i2c_setup_byte_rx(i2c_bus);
> + } else {
> + if (i2c_bus->mode == DMA_MODE)
> + return ast2600_i2c_setup_dma_tx(AST2600_I2CM_START_CMD, i2c_bus);
> + else if (i2c_bus->mode == BUFF_MODE)
> + return ast2600_i2c_setup_buff_tx(AST2600_I2CM_START_CMD, i2c_bus);
> + else
> + return ast2600_i2c_setup_byte_tx(AST2600_I2CM_START_CMD, i2c_bus);
> + }
> +}
> +
> +static int ast2600_i2c_irq_err_to_errno(u32 irq_status)
> +{
> + if (irq_status & AST2600_I2CM_ARBIT_LOSS)
> + return -EAGAIN;
> + if (irq_status & (AST2600_I2CM_SDA_DL_TO | AST2600_I2CM_SCL_LOW_TO))
> + return -EBUSY;
> + if (irq_status & (AST2600_I2CM_ABNORMAL))
> + return -EPROTO;
> +
> + return 0;
> +}
> +
> +static void ast2600_i2c_controller_package_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
> +{
> + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
> + u32 cmd = AST2600_I2CM_PKT_EN;
> + int xfer_len;
> + int i;
> +
> + sts &= ~AST2600_I2CM_PKT_DONE;
> + writel(AST2600_I2CM_PKT_DONE, i2c_bus->reg_base + AST2600_I2CM_ISR);
> + switch (sts) {
> + case AST2600_I2CM_PKT_ERROR:
> + i2c_bus->cmd_err = -EAGAIN;
> + complete(&i2c_bus->cmd_complete);
> + break;
> + case AST2600_I2CM_PKT_ERROR | AST2600_I2CM_TX_NAK: /* a0 fix for issue */
> + fallthrough;
> + case AST2600_I2CM_PKT_ERROR | AST2600_I2CM_TX_NAK | AST2600_I2CM_NORMAL_STOP:
> + i2c_bus->cmd_err = -ENXIO;
> + complete(&i2c_bus->cmd_complete);
> + break;
> + case AST2600_I2CM_NORMAL_STOP:
> + /* write 0 byte only have stop isr */
> + i2c_bus->msgs_index++;
> + if (i2c_bus->msgs_index < i2c_bus->msgs_count) {
> + if (ast2600_i2c_do_start(i2c_bus)) {
> + i2c_bus->cmd_err = -ENOMEM;
> + complete(&i2c_bus->cmd_complete);
> + }
> + } else {
> + i2c_bus->cmd_err = i2c_bus->msgs_index;
> + complete(&i2c_bus->cmd_complete);
> + }
> + break;
> + case AST2600_I2CM_TX_ACK:
> + case AST2600_I2CM_TX_ACK | AST2600_I2CM_NORMAL_STOP:
> + if (i2c_bus->mode == DMA_MODE)
> + xfer_len = AST2600_I2C_GET_TX_DMA_LEN(readl(i2c_bus->reg_base +
> + AST2600_I2CM_DMA_LEN_STS));
> + else if (i2c_bus->mode == BUFF_MODE)
> + xfer_len = AST2600_I2CC_GET_TX_BUF_LEN(readl(i2c_bus->reg_base +
> + AST2600_I2CC_BUFF_CTRL));
> + else
> + xfer_len = 1;
> +
> + i2c_bus->controller_xfer_cnt += xfer_len;
> +
> + if (i2c_bus->controller_xfer_cnt == msg->len) {
> + if (i2c_bus->mode == DMA_MODE) {
> + dma_unmap_single(i2c_bus->dev, i2c_bus->controller_dma_addr,
> + msg->len, DMA_TO_DEVICE);
> + i2c_put_dma_safe_msg_buf(i2c_bus->controller_dma_safe_buf,
> + msg, true);
> + i2c_bus->controller_dma_safe_buf = NULL;
> + }
> + i2c_bus->msgs_index++;
> + if (i2c_bus->msgs_index == i2c_bus->msgs_count) {
> + i2c_bus->cmd_err = i2c_bus->msgs_index;
> + complete(&i2c_bus->cmd_complete);
> + } else {
> + if (ast2600_i2c_do_start(i2c_bus)) {
> + i2c_bus->cmd_err = -ENOMEM;
> + complete(&i2c_bus->cmd_complete);
> + }
> + }
> + } else {
> + if (i2c_bus->mode == DMA_MODE)
> + ast2600_i2c_setup_dma_tx(0, i2c_bus);
> + else if (i2c_bus->mode == BUFF_MODE)
> + ast2600_i2c_setup_buff_tx(0, i2c_bus);
> + else
> + ast2600_i2c_setup_byte_tx(0, i2c_bus);
> + }
> + break;
> + case AST2600_I2CM_RX_DONE:
> + case AST2600_I2CM_RX_DONE | AST2600_I2CM_NORMAL_STOP:
> + /* do next rx */
> + if (i2c_bus->mode == DMA_MODE) {
> + xfer_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
> + AST2600_I2CM_DMA_LEN_STS));
> + } else if (i2c_bus->mode == BUFF_MODE) {
> + xfer_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
> + AST2600_I2CC_BUFF_CTRL));
> + for (i = 0; i < xfer_len; i++)
> + msg->buf[i2c_bus->controller_xfer_cnt + i] =
> + readb(i2c_bus->buf_base + 0x10 + i);
> + } else {
> + xfer_len = 1;
> + msg->buf[i2c_bus->controller_xfer_cnt] =
> + AST2600_I2CC_GET_RX_BUFF(readl(i2c_bus->reg_base +
> + AST2600_I2CC_STS_AND_BUFF));
> + }
> +
> + if (msg->flags & I2C_M_RECV_LEN) {
> + msg->len = min_t(unsigned int, msg->buf[0], I2C_SMBUS_BLOCK_MAX);
> + msg->len += ((msg->flags & I2C_CLIENT_PEC) ? 2 : 1);
> + msg->flags &= ~I2C_M_RECV_LEN;
> + }
> + i2c_bus->controller_xfer_cnt += xfer_len;
> +
> + if (i2c_bus->controller_xfer_cnt == msg->len) {
> + if (i2c_bus->mode == DMA_MODE) {
> + dma_unmap_single(i2c_bus->dev, i2c_bus->controller_dma_addr,
> + msg->len, DMA_FROM_DEVICE);
> + i2c_put_dma_safe_msg_buf(i2c_bus->controller_dma_safe_buf,
> + msg, true);
> + i2c_bus->controller_dma_safe_buf = NULL;
> + }
> +
> + i2c_bus->msgs_index++;
> + if (i2c_bus->msgs_index == i2c_bus->msgs_count) {
> + i2c_bus->cmd_err = i2c_bus->msgs_index;
> + complete(&i2c_bus->cmd_complete);
> + } else {
> + if (ast2600_i2c_do_start(i2c_bus)) {
> + i2c_bus->cmd_err = -ENOMEM;
> + complete(&i2c_bus->cmd_complete);
> + }
> + }
> + } else {
> + /* next rx */
> + cmd |= AST2600_I2CM_RX_CMD;
> + if (i2c_bus->mode == DMA_MODE) {
> + cmd |= AST2600_I2CM_RX_DMA_EN;
> + xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
> + if (xfer_len > AST2600_I2C_DMA_SIZE) {
> + xfer_len = AST2600_I2C_DMA_SIZE;
> + } else {
> + if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
> + cmd |= CONTROLLER_TRIGGER_LAST_STOP;
> + }
> + writel(AST2600_I2CM_SET_RX_DMA_LEN(xfer_len - 1),
> + i2c_bus->reg_base + AST2600_I2CM_DMA_LEN);
> + writel(i2c_bus->controller_dma_addr + i2c_bus->controller_xfer_cnt,
> + i2c_bus->reg_base + AST2600_I2CM_RX_DMA);
> + } else if (i2c_bus->mode == BUFF_MODE) {
> + cmd |= AST2600_I2CM_RX_BUFF_EN;
> + xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
> + if (xfer_len > i2c_bus->buf_size) {
> + xfer_len = i2c_bus->buf_size;
> + } else {
> + if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
> + cmd |= CONTROLLER_TRIGGER_LAST_STOP;
> + }
> + writel(AST2600_I2CC_SET_RX_BUF_LEN(xfer_len),
> + i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
> + } else {
> + if ((i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) &&
> + ((i2c_bus->controller_xfer_cnt + 1) == msg->len)) {
> + cmd |= CONTROLLER_TRIGGER_LAST_STOP;
> + }
> + }
> + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
> + }
> + break;
> + default:
> + dev_dbg(i2c_bus->dev, "unhandled sts %x\n", sts);
> + break;
> + }
> +}
> +
> +static int ast2600_i2c_controller_irq(struct ast2600_i2c_bus *i2c_bus)
> +{
> + u32 sts = readl(i2c_bus->reg_base + AST2600_I2CM_ISR);
> + u32 ctrl;
> +
> + sts &= ~AST2600_I2CM_SMBUS_ALT;
> +
> + if (AST2600_I2CM_BUS_RECOVER_FAIL & sts) {
> + 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) {
> + writel(AST2600_I2CM_BUS_RECOVER, i2c_bus->reg_base + AST2600_I2CM_ISR);
> + i2c_bus->cmd_err = 0;
> + complete(&i2c_bus->cmd_complete);
> + return 1;
> + }
> +
> + i2c_bus->cmd_err = ast2600_i2c_irq_err_to_errno(sts);
> + if (i2c_bus->cmd_err) {
> + 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_controller_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;
> +
> + return IRQ_RETVAL(ast2600_i2c_controller_irq(i2c_bus));
> +}
> +
> +static int ast2600_i2c_controller_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
> +{
> + struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(adap);
> + unsigned long timeout;
> + int ret;
> +
> + if (!i2c_bus->multi_master &&
> + (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) & AST2600_I2CC_BUS_BUSY_STS)) {
> + ret = ast2600_i2c_recover_bus(i2c_bus);
> + if (ret)
> + return ret;
> + }
> +
> + i2c_bus->cmd_err = 0;
> + i2c_bus->msgs = msgs;
> + i2c_bus->msgs_index = 0;
> + i2c_bus->msgs_count = num;
> + reinit_completion(&i2c_bus->cmd_complete);
> + ret = ast2600_i2c_do_start(i2c_bus);
> + if (ret)
> + goto controller_out;
> + timeout = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
> + if (timeout == 0) {
> + u32 ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> +
> + dev_dbg(i2c_bus->dev, "timeout isr[%x], sts[%x]\n",
> + readl(i2c_bus->reg_base + AST2600_I2CM_ISR),
> + readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
> + writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> + writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> +
> + if (i2c_bus->multi_master &&
> + (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) &
> + AST2600_I2CC_BUS_BUSY_STS))
> + ast2600_i2c_recover_bus(i2c_bus);
> +
> + ret = -ETIMEDOUT;
> + } else {
> + ret = i2c_bus->cmd_err;
> + }
> +
> + dev_dbg(i2c_bus->dev, "bus%d-m: %d end\n", i2c_bus->adap.nr, i2c_bus->cmd_err);
> +
> +controller_out:
> + if (i2c_bus->mode == DMA_MODE) {
> + kfree(i2c_bus->controller_dma_safe_buf);
> + i2c_bus->controller_dma_safe_buf = NULL;
> + }
> +
> + return ret;
> +}
> +
> +static void ast2600_i2c_init(struct ast2600_i2c_bus *i2c_bus)
> +{
> + struct platform_device *pdev = to_platform_device(i2c_bus->dev);
> + u32 fun_ctrl = AST2600_I2CC_BUS_AUTO_RELEASE | AST2600_I2CC_MASTER_EN;
> +
> + /* I2C Reset */
> + writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> +
> + i2c_bus->multi_master = device_property_read_bool(&pdev->dev, "multi-master");
> + if (!i2c_bus->multi_master)
> + fun_ctrl |= AST2600_I2CC_MULTI_MASTER_DIS;
> +
> + /* Enable Controller Mode */
> + writel(fun_ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> + /* disable target address */
> + writel(0, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
> +
> + /* Set AC Timing */
> + writel(ast2600_select_i2c_clock(i2c_bus), i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
> +
> + /* Clear Interrupt */
> + writel(GENMASK(27, 0), i2c_bus->reg_base + AST2600_I2CM_ISR);
> +}
> +
> +static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
> +{
> + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
> +}
> +
> +static const struct i2c_algorithm i2c_ast2600_algorithm = {
> + .xfer = ast2600_i2c_controller_xfer,
> + .functionality = ast2600_i2c_functionality,
> +};
> +
> +static int ast2600_i2c_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct ast2600_i2c_bus *i2c_bus;
> + struct resource *res;
> + u32 global_ctrl;
> + int ret;
> +
> + i2c_bus = devm_kzalloc(dev, sizeof(*i2c_bus), GFP_KERNEL);
> + if (!i2c_bus)
> + return -ENOMEM;
> +
> + i2c_bus->reg_base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(i2c_bus->reg_base))
> + return PTR_ERR(i2c_bus->reg_base);
> +
> + i2c_bus->rst = devm_reset_control_get_shared(dev, NULL);
> + if (IS_ERR(i2c_bus->rst))
> + return dev_err_probe(dev, PTR_ERR(i2c_bus->rst), "Missing reset ctrl\n");
> +
> + reset_control_deassert(i2c_bus->rst);
> +
> + i2c_bus->global_regs =
> + syscon_regmap_lookup_by_phandle(dev_of_node(dev), "aspeed,global-regs");
> + if (IS_ERR(i2c_bus->global_regs))
> + return PTR_ERR(i2c_bus->global_regs);
> +
> + regmap_read(i2c_bus->global_regs, AST2600_I2CG_CTRL, &global_ctrl);
> + if ((global_ctrl & AST2600_GLOBAL_INIT) != AST2600_GLOBAL_INIT) {
> + regmap_write(i2c_bus->global_regs, AST2600_I2CG_CTRL, AST2600_GLOBAL_INIT);
> + regmap_write(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, I2CCG_DIV_CTRL);
> + }
> +
> + i2c_bus->dev = dev;
> + i2c_bus->mode = BUFF_MODE;
> +
> + if (device_property_read_bool(dev, "aspeed,enable-dma"))
> + i2c_bus->mode = DMA_MODE;
> +
> + if (i2c_bus->mode == BUFF_MODE) {
> + i2c_bus->buf_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
> + if (IS_ERR(i2c_bus->buf_base))
> + i2c_bus->mode = BYTE_MODE;
> + else
> + i2c_bus->buf_size = resource_size(res) / 2;
> + }
> +
> + /*
> + * i2c timeout counter: use base clk4 1Mhz,
> + * per unit: 1/(1000/4096) = 4096us
> + */
> + ret = device_property_read_u32(dev, "i2c-scl-clk-low-timeout-us", &i2c_bus->timeout);
> + if (!ret)
> + i2c_bus->timeout /= 4096;
> +
> + init_completion(&i2c_bus->cmd_complete);
> +
> + i2c_bus->irq = platform_get_irq(pdev, 0);
> + if (i2c_bus->irq < 0)
> + return i2c_bus->irq;
> +
> + platform_set_drvdata(pdev, i2c_bus);
> +
> + i2c_bus->clk = devm_clk_get(i2c_bus->dev, NULL);
> + if (IS_ERR(i2c_bus->clk))
> + return dev_err_probe(i2c_bus->dev, PTR_ERR(i2c_bus->clk), "Can't get clock\n");
> +
> + i2c_bus->apb_clk = clk_get_rate(i2c_bus->clk);
> +
> + i2c_parse_fw_timings(i2c_bus->dev, &i2c_bus->timing_info, true);
> +
> + /* 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;
> + device_set_node(&i2c_bus->adap.dev, dev_fwnode(dev));
> + i2c_bus->adap.algo_data = i2c_bus;
> + strscpy(i2c_bus->adap.name, pdev->name);
> + i2c_set_adapdata(&i2c_bus->adap, i2c_bus);
> +
> + ast2600_i2c_init(i2c_bus);
> +
> + ret = devm_request_irq(dev, i2c_bus->irq, ast2600_i2c_bus_irq, 0,
> + dev_name(dev), i2c_bus);
> + if (ret < 0)
> + return dev_err_probe(dev, ret, "Unable to request irq %d\n", i2c_bus->irq);
> +
> + writel(AST2600_I2CM_PKT_DONE | AST2600_I2CM_BUS_RECOVER,
> + i2c_bus->reg_base + AST2600_I2CM_IER);
> +
> + ret = devm_i2c_add_adapter(dev, &i2c_bus->adap);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static void 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);
> +}
> +
> +static const struct of_device_id ast2600_i2c_bus_of_table[] = {
> + {
> + .compatible = "aspeed,ast2600-i2cv2",
> + },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, ast2600_i2c_bus_of_table);
> +
> +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 at aspeedtech.com>");
> +MODULE_DESCRIPTION("ASPEED AST2600 I2C Controller Driver");
> +MODULE_LICENSE("GPL");
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