Re: [PATCH resend v4] i2c: hibvt: add Hisilicon BVT I2C controller driver

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Hi Wolfram,

On 2016/10/21 16:17, Pan Wen wrote:
> add Hisilicon BVT I2C controller driver support.
> 
> Signed-off-by: Pan Wen <wenpan@xxxxxxxxxxxxx>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> change log
> v4:
> Modify the default frequency to 100KHz.
> v3:
> Add a SoC specific compatible string.
> v2:
> 1)Fixed a compile error.
> 2)Dropped the clock-names property.
>  .../devicetree/bindings/i2c/i2c-hibvt.txt          |  24 +
>  drivers/i2c/busses/Kconfig                         |  10 +
>  drivers/i2c/busses/Makefile                        |   1 +
>  drivers/i2c/busses/i2c-hibvt.c                     | 737 +++++++++++++++++++++
>  4 files changed, 772 insertions(+)

Could you give us some comments on this patch?
If there are some issues about it, please let us know.
Thank you very much!

Best Regards,
Jiancheng

>  create mode 100644 Documentation/devicetree/bindings/i2c/i2c-hibvt.txt
>  create mode 100644 drivers/i2c/busses/i2c-hibvt.c
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-hibvt.txt b/Documentation/devicetree/bindings/i2c/i2c-hibvt.txt
> new file mode 100644
> index 0000000..db3d2e2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/i2c-hibvt.txt
> @@ -0,0 +1,24 @@
> +Hisilicon BVT I2C master controller
> +
> +Required properties:
> +- compatible: should be "hisilicon,hibvt-i2c" and one of the following:
> +	"hisilicon,hi3516cv300-i2c"
> +- reg: physical base address of the controller and length of memory mapped.
> +     region.
> +- interrupts: interrupt number to the cpu.
> +- clocks: phandles to input clocks.
> +
> +Optional properties:
> +- clock-frequency: Desired I2C bus frequency in Hz, otherwise defaults to 100000.
> +
> +Other properties:
> +see Documentation/devicetree/bindings/i2c/i2c.txt.
> +
> +Examples:
> +i2c_bus0: i2c@12110000 {
> +	compatible = "hisilicon,hi3516cv300-i2c", "hisilicon,hibvt-i2c";
> +	reg = <0x12110000 0x100>;
> +	interrupts = <20>;
> +	clocks = <&crg_ctrl HI3516CV300_APB_CLK>;
> +	clock-frequency = <100000>;
> +};
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 5c3993b..fc1b679 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -555,6 +555,16 @@ config I2C_GPIO
>  	  This is a very simple bitbanging I2C driver utilizing the
>  	  arch-neutral GPIO API to control the SCL and SDA lines.
>  
> +config I2C_HIBVT
> +	tristate "Hisilicon BVT I2C Controller"
> +	depends on ARCH_HISI
> +	help
> +	  Say Y here to include support for Hisilicon BVT I2C controller in the
> +	  Hisilicon BVT SoCs.
> +
> +	  This driver can also be built as a module.  If so, the module
> +	  will be called i2c-hibvt.
> +
>  config I2C_HIGHLANDER
>  	tristate "Highlander FPGA SMBus interface"
>  	depends on SH_HIGHLANDER
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index 37f2819..42ef2e0 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -51,6 +51,7 @@ obj-$(CONFIG_I2C_EG20T)		+= i2c-eg20t.o
>  obj-$(CONFIG_I2C_EMEV2)		+= i2c-emev2.o
>  obj-$(CONFIG_I2C_EXYNOS5)	+= i2c-exynos5.o
>  obj-$(CONFIG_I2C_GPIO)		+= i2c-gpio.o
> +obj-$(CONFIG_I2C_HIBVT)		+= i2c-hibvt.o
>  obj-$(CONFIG_I2C_HIGHLANDER)	+= i2c-highlander.o
>  obj-$(CONFIG_I2C_HIX5HD2)	+= i2c-hix5hd2.o
>  obj-$(CONFIG_I2C_IBM_IIC)	+= i2c-ibm_iic.o
> diff --git a/drivers/i2c/busses/i2c-hibvt.c b/drivers/i2c/busses/i2c-hibvt.c
> new file mode 100644
> index 0000000..e8af63e
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-hibvt.c
> @@ -0,0 +1,737 @@
> +/*
> + * Hisilicon BVT I2C Controller Driver
> + *
> + * Copyright (c) 2016 HiSilicon Technologies Co., Ltd.
> + *
> + * Authors: wenpan@xxxxxxxxxxxxx
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + *
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +/*
> + * I2C Registers offsets
> + */
> +#define HIBVT_I2C_GLB		0x0
> +#define HIBVT_I2C_SCL_H		0x4
> +#define HIBVT_I2C_SCL_L		0x8
> +#define HIBVT_I2C_DATA1		0x10
> +#define HIBVT_I2C_TXF		0x20
> +#define HIBVT_I2C_RXF		0x24
> +#define HIBVT_I2C_CMD_BASE	0x30
> +#define HIBVT_I2C_LOOP1		0xb0
> +#define HIBVT_I2C_DST1		0xb4
> +#define HIBVT_I2C_TX_WATER	0xc8
> +#define HIBVT_I2C_RX_WATER	0xcc
> +#define HIBVT_I2C_CTRL1		0xd0
> +#define HIBVT_I2C_STAT		0xd8
> +#define HIBVT_I2C_INTR_RAW	0xe0
> +#define HIBVT_I2C_INTR_EN	0xe4
> +#define HIBVT_I2C_INTR_STAT	0xe8
> +
> +/*
> + * I2C Global Config Register -- HIBVT_I2C_GLB
> + */
> +#define GLB_EN_MASK		BIT(0)
> +#define GLB_SDA_HOLD_MASK	GENMASK(23, 8)
> +#define GLB_SDA_HOLD_SHIFT	(8)
> +
> +/*
> + * I2C Timing CMD Register -- HIBVT_I2C_CMD_BASE + n * 4 (n = 0, 1, 2, ... 31)
> + */
> +#define CMD_EXIT	0x0
> +#define CMD_TX_S	0x1
> +#define CMD_TX_D1_2	0x4
> +#define CMD_TX_D1_1	0x5
> +#define CMD_TX_FIFO	0x9
> +#define CMD_RX_FIFO	0x12
> +#define CMD_RX_ACK	0x13
> +#define CMD_IGN_ACK	0x15
> +#define CMD_TX_ACK	0x16
> +#define CMD_TX_NACK	0x17
> +#define CMD_JMP1	0x18
> +#define CMD_UP_TXF	0x1d
> +#define CMD_TX_RS	0x1e
> +#define CMD_TX_P	0x1f
> +
> +/*
> + * I2C Control Register 1 -- HIBVT_I2C_CTRL1
> + */
> +#define CTRL1_CMD_START_MASK	BIT(0)
> +
> +/*
> + * I2C Status Register -- HIBVT_I2C_STAT
> + */
> +#define STAT_RXF_NOE_MASK	BIT(16) /* RX FIFO not empty flag */
> +#define STAT_TXF_NOF_MASK	BIT(19) /* TX FIFO not full flag */
> +
> +
> +/*
> + * I2C Interrupt status and mask Register --
> + * HIBVT_I2C_INTR_RAW, HIBVT_I2C_STAT, HIBVT_I2C_INTR_STAT
> + */
> +#define INTR_ABORT_MASK		(BIT(0) | BIT(11))
> +#define INTR_RX_MASK		BIT(2)
> +#define INTR_TX_MASK		BIT(4)
> +#define INTR_CMD_DONE_MASK	BIT(12)
> +#define INTR_USE_MASK		(INTR_ABORT_MASK \
> +				|INTR_RX_MASK \
> +				| INTR_TX_MASK \
> +				| INTR_CMD_DONE_MASK)
> +#define INTR_ALL_MASK		GENMASK(31, 0)
> +
> +#define I2C_DEFAULT_FREQUENCY	100000
> +#define I2C_TXF_DEPTH		64
> +#define I2C_RXF_DEPTH		64
> +#define I2C_TXF_WATER		32
> +#define I2C_RXF_WATER		32
> +#define I2C_WAIT_TIMEOUT	0x10000
> +#define I2C_IRQ_TIMEOUT		(msecs_to_jiffies(1000))
> +
> +
> +struct hibvt_i2c_dev {
> +	struct device		*dev;
> +	struct i2c_adapter	adap;
> +	void __iomem		*base;
> +	struct clk		*clk;
> +	int			irq;
> +
> +	unsigned int		freq;
> +	struct i2c_msg		*msg;
> +	unsigned int		msg_num;
> +	unsigned int		msg_idx;
> +	unsigned int		msg_buf_ptr;
> +	struct completion	msg_complete;
> +
> +	spinlock_t		lock;
> +	int			status;
> +};
> +
> +static inline void hibvt_i2c_disable(struct hibvt_i2c_dev *i2c)
> +{
> +	unsigned int val;
> +
> +	val = readl(i2c->base + HIBVT_I2C_GLB);
> +	val &= ~GLB_EN_MASK;
> +	writel(val, i2c->base + HIBVT_I2C_GLB);
> +}
> +
> +static inline void hibvt_i2c_enable(struct hibvt_i2c_dev *i2c)
> +{
> +	unsigned int val;
> +
> +	val = readl(i2c->base + HIBVT_I2C_GLB);
> +	val |= GLB_EN_MASK;
> +	writel(val, i2c->base + HIBVT_I2C_GLB);
> +}
> +
> +static inline void hibvt_i2c_cfg_irq(struct hibvt_i2c_dev *i2c,
> +		unsigned int flag)
> +{
> +	writel(flag, i2c->base + HIBVT_I2C_INTR_EN);
> +}
> +
> +static inline void hibvt_i2c_disable_irq(struct hibvt_i2c_dev *i2c,
> +		unsigned int flag)
> +{
> +	unsigned int val;
> +
> +	val = readl(i2c->base + HIBVT_I2C_INTR_EN);
> +	val &= ~flag;
> +	writel(val, i2c->base + HIBVT_I2C_INTR_EN);
> +}
> +
> +static inline unsigned int hibvt_i2c_clr_irq(struct hibvt_i2c_dev *i2c)
> +{
> +	unsigned int val;
> +
> +	val = readl(i2c->base + HIBVT_I2C_INTR_STAT);
> +	writel(INTR_ALL_MASK, i2c->base + HIBVT_I2C_INTR_RAW);
> +
> +	return val;
> +}
> +
> +static inline void hibvt_i2c_cmdreg_set(struct hibvt_i2c_dev *i2c,
> +		unsigned int cmd, unsigned int *offset)
> +{
> +	dev_dbg(i2c->dev, "hii2c reg: offset=0x%x, cmd=0x%x...\n",
> +			*offset * 4, cmd);
> +	writel(cmd, i2c->base + HIBVT_I2C_CMD_BASE + *offset * 4);
> +	(*offset)++;
> +}
> +
> +/*
> + * config i2c slave addr
> + */
> +static inline void hibvt_i2c_set_addr(struct hibvt_i2c_dev *i2c)
> +{
> +	struct i2c_msg *msg = i2c->msg;
> +	u16 addr;
> +
> +	if (msg->flags & I2C_M_TEN) {
> +		/* First byte is 11110XX0 where XX is upper 2 bits */
> +		addr = ((msg->addr & 0x300) << 1) | 0xf000;
> +		if (msg->flags & I2C_M_RD)
> +			addr |= 1 << 8;
> +
> +		/* Second byte is the remaining 8 bits */
> +		addr |= msg->addr & 0xff;
> +	} else {
> +		addr = (msg->addr & 0x7f) << 1;
> +		if (msg->flags & I2C_M_RD)
> +			addr |= 1;
> +	}
> +
> +	writel(addr, i2c->base + HIBVT_I2C_DATA1);
> +}
> +
> +/*
> + * Start command sequence
> + */
> +static inline void hibvt_i2c_start_cmd(struct hibvt_i2c_dev *i2c)
> +{
> +	unsigned int val;
> +
> +	val = readl(i2c->base + HIBVT_I2C_CTRL1);
> +	val |= CTRL1_CMD_START_MASK;
> +	writel(val, i2c->base + HIBVT_I2C_CTRL1);
> +}
> +
> +static int hibvt_i2c_wait_rx_noempty(struct hibvt_i2c_dev *i2c)
> +{
> +	unsigned int time_cnt = 0;
> +	unsigned int val;
> +
> +	do {
> +		val = readl(i2c->base + HIBVT_I2C_STAT);
> +		if (val & STAT_RXF_NOE_MASK)
> +			return 0;
> +
> +		udelay(50);
> +	} while (time_cnt++ < I2C_WAIT_TIMEOUT);
> +
> +	dev_err(i2c->dev, "wait rx no empty timeout, RIS: 0x%x, SR: 0x%x\n",
> +			readl(i2c->base + HIBVT_I2C_INTR_RAW), val);
> +	return -EIO;
> +}
> +
> +static int hibvt_i2c_wait_tx_nofull(struct hibvt_i2c_dev *i2c)
> +{
> +	unsigned int time_cnt = 0;
> +	unsigned int val;
> +
> +	do {
> +		val = readl(i2c->base + HIBVT_I2C_STAT);
> +		if (val & STAT_TXF_NOF_MASK)
> +			return 0;
> +
> +		udelay(50);
> +	} while (time_cnt++ < I2C_WAIT_TIMEOUT);
> +
> +	dev_err(i2c->dev, "wait rx no empty timeout, RIS: 0x%x, SR: 0x%x\n",
> +			readl(i2c->base + HIBVT_I2C_INTR_RAW), val);
> +	return -EIO;
> +}
> +
> +static int hibvt_i2c_wait_idle(struct hibvt_i2c_dev *i2c)
> +{
> +	unsigned int time_cnt = 0;
> +	unsigned int val;
> +
> +	do {
> +		val = readl(i2c->base + HIBVT_I2C_INTR_RAW);
> +		if (val & (INTR_ABORT_MASK)) {
> +			dev_err(i2c->dev, "wait idle abort!, RIS: 0x%x\n",
> +					val);
> +			return -EIO;
> +		}
> +
> +		if (val & INTR_CMD_DONE_MASK)
> +			return 0;
> +
> +		udelay(50);
> +	} while (time_cnt++ < I2C_WAIT_TIMEOUT);
> +
> +	dev_err(i2c->dev, "wait idle timeout, RIS: 0x%x, SR: 0x%x\n",
> +			val, readl(i2c->base + HIBVT_I2C_STAT));
> +
> +	return -EIO;
> +}
> +
> +static void hibvt_i2c_set_freq(struct hibvt_i2c_dev *i2c)
> +{
> +	unsigned int max_freq, freq;
> +	unsigned int clk_rate;
> +	unsigned int val, sda_hold;
> +
> +	freq = i2c->freq;
> +	clk_rate = clk_get_rate(i2c->clk);
> +	max_freq = clk_rate >> 1;
> +
> +	if (freq > max_freq) {
> +		i2c->freq = max_freq;
> +		freq = i2c->freq;
> +	}
> +
> +	if (freq <= 100000) {
> +		val = clk_rate / (freq * 2) - 1;
> +		writel(val, i2c->base + HIBVT_I2C_SCL_H);
> +		writel(val, i2c->base + HIBVT_I2C_SCL_L);
> +	} else {
> +		val = (clk_rate * 36) / (freq * 100);
> +		writel(val, i2c->base + HIBVT_I2C_SCL_H);
> +		val = (clk_rate * 64) / (freq * 100);
> +		writel(val, i2c->base + HIBVT_I2C_SCL_L);
> +	}
> +
> +	sda_hold = val * 3 / 10;
> +	sda_hold = (sda_hold << GLB_SDA_HOLD_SHIFT) & GLB_SDA_HOLD_MASK;
> +	val = readl(i2c->base + HIBVT_I2C_GLB);
> +	val &= ~GLB_SDA_HOLD_MASK;
> +	val |= sda_hold;
> +	writel(val, i2c->base + HIBVT_I2C_GLB);
> +}
> +
> +/*
> + * set i2c controller TX and RX FIFO water
> + */
> +static inline void hibvt_i2c_set_water(struct hibvt_i2c_dev *i2c)
> +{
> +	writel(I2C_TXF_WATER, i2c->base + HIBVT_I2C_TX_WATER);
> +	writel(I2C_RXF_WATER, i2c->base + HIBVT_I2C_RX_WATER);
> +}
> +
> +/*
> + * initialise the controller, set i2c bus interface freq
> + */
> +static void hibvt_i2c_hw_init(struct hibvt_i2c_dev *i2c)
> +{
> +	hibvt_i2c_disable(i2c);
> +	hibvt_i2c_disable_irq(i2c, INTR_ALL_MASK);
> +	hibvt_i2c_set_freq(i2c);
> +	hibvt_i2c_set_water(i2c);
> +}
> +
> +/*
> + * hibvt_i2c_cfg_cmd - config i2c controller command sequence
> + *
> + * After all the timing command is configured,
> + * and then start the command, you can i2c communication,
> + * and then only need to read and write i2c fifo.
> + */
> +static void hibvt_i2c_cfg_cmd(struct hibvt_i2c_dev *i2c)
> +{
> +	struct i2c_msg *msg = i2c->msg;
> +	int offset = 0;
> +
> +	if (i2c->msg_idx == 0)
> +		hibvt_i2c_cmdreg_set(i2c, CMD_TX_S, &offset);
> +	else
> +		hibvt_i2c_cmdreg_set(i2c, CMD_TX_RS, &offset);
> +
> +	if (msg->flags & I2C_M_TEN) {
> +		if (i2c->msg_idx == 0) {
> +			hibvt_i2c_cmdreg_set(i2c, CMD_TX_D1_2, &offset);
> +			hibvt_i2c_cmdreg_set(i2c, CMD_TX_D1_1, &offset);
> +		} else {
> +			hibvt_i2c_cmdreg_set(i2c, CMD_TX_D1_2, &offset);
> +		}
> +	} else {
> +		hibvt_i2c_cmdreg_set(i2c, CMD_TX_D1_1, &offset);
> +	}
> +
> +	if (msg->flags & I2C_M_IGNORE_NAK)
> +		hibvt_i2c_cmdreg_set(i2c, CMD_IGN_ACK, &offset);
> +	else
> +		hibvt_i2c_cmdreg_set(i2c, CMD_RX_ACK, &offset);
> +
> +	if (msg->flags & I2C_M_RD) {
> +		if (msg->len >= 2) {
> +			writel(offset, i2c->base + HIBVT_I2C_DST1);
> +			writel(msg->len - 2, i2c->base + HIBVT_I2C_LOOP1);
> +			hibvt_i2c_cmdreg_set(i2c, CMD_RX_FIFO, &offset);
> +			hibvt_i2c_cmdreg_set(i2c, CMD_TX_ACK, &offset);
> +			hibvt_i2c_cmdreg_set(i2c, CMD_JMP1, &offset);
> +		}
> +		hibvt_i2c_cmdreg_set(i2c, CMD_RX_FIFO, &offset);
> +		hibvt_i2c_cmdreg_set(i2c, CMD_TX_NACK, &offset);
> +	} else {
> +		writel(offset, i2c->base + HIBVT_I2C_DST1);
> +		writel(msg->len - 1, i2c->base + HIBVT_I2C_LOOP1);
> +		hibvt_i2c_cmdreg_set(i2c, CMD_UP_TXF, &offset);
> +		hibvt_i2c_cmdreg_set(i2c, CMD_TX_FIFO, &offset);
> +
> +		if (msg->flags & I2C_M_IGNORE_NAK)
> +			hibvt_i2c_cmdreg_set(i2c, CMD_IGN_ACK, &offset);
> +		else
> +			hibvt_i2c_cmdreg_set(i2c, CMD_RX_ACK, &offset);
> +
> +		hibvt_i2c_cmdreg_set(i2c, CMD_JMP1, &offset);
> +	}
> +
> +	if ((i2c->msg_idx == (i2c->msg_num - 1)) || (msg->flags & I2C_M_STOP)) {
> +		dev_dbg(i2c->dev, "run to %s %d...TX STOP\n",
> +				__func__, __LINE__);
> +		hibvt_i2c_cmdreg_set(i2c, CMD_TX_P, &offset);
> +	}
> +
> +	hibvt_i2c_cmdreg_set(i2c, CMD_EXIT, &offset);
> +}
> +
> +static int hibvt_i2c_polling_xfer_one_msg(struct hibvt_i2c_dev *i2c)
> +{
> +	int status;
> +	unsigned int val;
> +	struct i2c_msg *msg = i2c->msg;
> +
> +	dev_dbg(i2c->dev, "[%s,%d]msg->flags=0x%x, len=0x%x\n",
> +			__func__, __LINE__, msg->flags, msg->len);
> +
> +	hibvt_i2c_enable(i2c);
> +	hibvt_i2c_clr_irq(i2c);
> +	hibvt_i2c_set_addr(i2c);
> +	hibvt_i2c_cfg_cmd(i2c);
> +	hibvt_i2c_start_cmd(i2c);
> +
> +	i2c->msg_buf_ptr = 0;
> +
> +	if (msg->flags & I2C_M_RD) {
> +		while (i2c->msg_buf_ptr < msg->len) {
> +			status = hibvt_i2c_wait_rx_noempty(i2c);
> +			if (status)
> +				goto end;
> +
> +			val = readl(i2c->base + HIBVT_I2C_RXF);
> +			msg->buf[i2c->msg_buf_ptr] = val;
> +			i2c->msg_buf_ptr++;
> +
> +		}
> +	} else {
> +		while (i2c->msg_buf_ptr < msg->len) {
> +			status = hibvt_i2c_wait_tx_nofull(i2c);
> +			if (status)
> +				goto end;
> +
> +			val = msg->buf[i2c->msg_buf_ptr];
> +			writel(val, i2c->base + HIBVT_I2C_TXF);
> +			i2c->msg_buf_ptr++;
> +		}
> +	}
> +
> +	status = hibvt_i2c_wait_idle(i2c);
> +end:
> +	hibvt_i2c_disable(i2c);
> +
> +	return status;
> +}
> +
> +static irqreturn_t hibvt_i2c_isr(int irq, void *dev_id)
> +{
> +	struct hibvt_i2c_dev *i2c = dev_id;
> +	unsigned int irq_status;
> +	struct i2c_msg *msg = i2c->msg;
> +
> +	spin_lock(&i2c->lock);
> +
> +	irq_status = hibvt_i2c_clr_irq(i2c);
> +	dev_dbg(i2c->dev, "%s RIS:  0x%x\n", __func__, irq_status);
> +
> +	if (!irq_status) {
> +		dev_dbg(i2c->dev, "no irq\n");
> +		goto end;
> +	}
> +
> +	if (irq_status & INTR_ABORT_MASK) {
> +		dev_err(i2c->dev, "irq handle abort, RIS: 0x%x\n",
> +				irq_status);
> +		i2c->status = -EIO;
> +		hibvt_i2c_disable_irq(i2c, INTR_ALL_MASK);
> +
> +		complete(&i2c->msg_complete);
> +		goto end;
> +	}
> +
> +	if (msg->flags & I2C_M_RD) {
> +		while ((readl(i2c->base + HIBVT_I2C_STAT) & STAT_RXF_NOE_MASK)
> +				&& (i2c->msg_buf_ptr < msg->len)) {
> +			msg->buf[i2c->msg_buf_ptr] =
> +				readl(i2c->base + HIBVT_I2C_RXF);
> +			i2c->msg_buf_ptr++;
> +		}
> +	} else {
> +		while ((readl(i2c->base + HIBVT_I2C_STAT) & STAT_TXF_NOF_MASK)
> +				&& (i2c->msg_buf_ptr < msg->len)) {
> +			writel(msg->buf[i2c->msg_buf_ptr],
> +					i2c->base + HIBVT_I2C_TXF);
> +			i2c->msg_buf_ptr++;
> +		}
> +	}
> +
> +	if (i2c->msg_buf_ptr >= msg->len)
> +		hibvt_i2c_disable_irq(i2c, INTR_TX_MASK | INTR_RX_MASK);
> +
> +	if (irq_status & INTR_CMD_DONE_MASK) {
> +		dev_dbg(i2c->dev, "cmd done\n");
> +		i2c->status =  0;
> +		hibvt_i2c_disable_irq(i2c, INTR_ALL_MASK);
> +
> +		complete(&i2c->msg_complete);
> +	}
> +
> +end:
> +	spin_unlock(&i2c->lock);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int hibvt_i2c_interrupt_xfer_one_msg(struct hibvt_i2c_dev *i2c)
> +{
> +	int status;
> +	struct i2c_msg *msg = i2c->msg;
> +	unsigned long timeout;
> +	unsigned long flags;
> +
> +	dev_dbg(i2c->dev, "[%s,%d]msg->flags=0x%x, len=0x%x\n",
> +			__func__, __LINE__, msg->flags, msg->len);
> +
> +	reinit_completion(&i2c->msg_complete);
> +	i2c->msg_buf_ptr = 0;
> +	i2c->status = -EIO;
> +
> +	spin_lock_irqsave(&i2c->lock, flags);
> +	hibvt_i2c_enable(i2c);
> +	hibvt_i2c_clr_irq(i2c);
> +	if (msg->flags & I2C_M_RD)
> +		hibvt_i2c_cfg_irq(i2c, INTR_USE_MASK & ~INTR_TX_MASK);
> +	else
> +		hibvt_i2c_cfg_irq(i2c, INTR_USE_MASK & ~INTR_RX_MASK);
> +
> +	hibvt_i2c_set_addr(i2c);
> +	hibvt_i2c_cfg_cmd(i2c);
> +	hibvt_i2c_start_cmd(i2c);
> +	spin_unlock_irqrestore(&i2c->lock, flags);
> +
> +	timeout = wait_for_completion_timeout(&i2c->msg_complete,
> +			I2C_IRQ_TIMEOUT);
> +
> +	if (timeout == 0) {
> +		hibvt_i2c_disable_irq(i2c, INTR_ALL_MASK);
> +		status = -EIO;
> +		dev_err(i2c->dev, "%s timeout\n",
> +			 msg->flags & I2C_M_RD ? "rx" : "tx");
> +	} else {
> +		status = i2c->status;
> +	}
> +
> +	hibvt_i2c_disable(i2c);
> +
> +	return status;
> +}
> +
> +/*
> + * Master transfer function
> + */
> +static int hibvt_i2c_xfer(struct i2c_adapter *adap,
> +			struct i2c_msg *msgs, int num)
> +{
> +	struct hibvt_i2c_dev *i2c = i2c_get_adapdata(adap);
> +	int status;
> +
> +	if (!msgs) {
> +		dev_err(i2c->dev, "msgs == NULL\n");
> +		return -EIO;
> +	}
> +
> +	i2c->msg = msgs;
> +	i2c->msg_num = num;
> +	i2c->msg_idx = 0;
> +
> +	if (i2c->irq >= 0) {
> +		while (i2c->msg_idx < i2c->msg_num) {
> +			status = hibvt_i2c_interrupt_xfer_one_msg(i2c);
> +			if (status)
> +				break;
> +
> +			i2c->msg++;
> +			i2c->msg_idx++;
> +		}
> +	} else {
> +		while (i2c->msg_idx < i2c->msg_num) {
> +			status = hibvt_i2c_polling_xfer_one_msg(i2c);
> +			if (status)
> +				break;
> +
> +			i2c->msg++;
> +			i2c->msg_idx++;
> +		}
> +	}
> +
> +	if (!status || i2c->msg_idx > 0)
> +		status = i2c->msg_idx;
> +
> +	return status;
> +}
> +
> +static u32 hibvt_i2c_func(struct i2c_adapter *adap)
> +{
> +	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR
> +		| I2C_FUNC_PROTOCOL_MANGLING;
> +}
> +
> +static const struct i2c_algorithm hibvt_i2c_algo = {
> +	.master_xfer		= hibvt_i2c_xfer,
> +	.functionality		= hibvt_i2c_func,
> +};
> +
> +static int hibvt_i2c_probe(struct platform_device *pdev)
> +{
> +	int status;
> +	struct hibvt_i2c_dev *i2c;
> +	struct i2c_adapter *adap;
> +	struct resource *res;
> +
> +	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
> +	if (!i2c)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, i2c);
> +	i2c->dev = &pdev->dev;
> +	spin_lock_init(&i2c->lock);
> +	init_completion(&i2c->msg_complete);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	i2c->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(i2c->base)) {
> +		dev_err(i2c->dev, "cannot ioremap resource\n");
> +		return -ENOMEM;
> +	}
> +
> +	i2c->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(i2c->clk)) {
> +		dev_err(i2c->dev, "cannot get clock\n");
> +		return -ENOENT;
> +	}
> +	clk_prepare_enable(i2c->clk);
> +
> +	if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
> +				&i2c->freq)) {
> +		dev_warn(i2c->dev, "setting default clock-frequency@%dHz\n",
> +				I2C_DEFAULT_FREQUENCY);
> +		i2c->freq = I2C_DEFAULT_FREQUENCY;
> +	}
> +
> +	/* i2c controller initialization, disable interrupt */
> +	hibvt_i2c_hw_init(i2c);
> +
> +	i2c->irq = platform_get_irq(pdev, 0);
> +	status = devm_request_irq(&pdev->dev, i2c->irq, hibvt_i2c_isr,
> +			IRQF_SHARED, dev_name(&pdev->dev), i2c);
> +	if (status) {
> +		dev_dbg(i2c->dev, "falling back to polling mode");
> +		i2c->irq = -1;
> +	}
> +
> +	adap = &i2c->adap;
> +	i2c_set_adapdata(adap, i2c);
> +	adap->owner = THIS_MODULE;
> +	strlcpy(adap->name, "hibvt-i2c", sizeof(adap->name));
> +	adap->dev.parent = &pdev->dev;
> +	adap->dev.of_node = pdev->dev.of_node;
> +	adap->algo = &hibvt_i2c_algo;
> +
> +	/* Add the i2c adapter */
> +	status = i2c_add_adapter(adap);
> +	if (status) {
> +		dev_err(i2c->dev, "failed to add bus to i2c core\n");
> +		goto err_add_adapter;
> +	}
> +
> +	dev_info(i2c->dev, "%s%d@%dhz registered\n",
> +			adap->name, adap->nr, i2c->freq);
> +
> +	return 0;
> +
> +err_add_adapter:
> +	clk_disable_unprepare(i2c->clk);
> +	return status;
> +}
> +
> +static int hibvt_i2c_remove(struct platform_device *pdev)
> +{
> +	struct hibvt_i2c_dev *i2c = platform_get_drvdata(pdev);
> +
> +	clk_disable_unprepare(i2c->clk);
> +	i2c_del_adapter(&i2c->adap);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int hibvt_i2c_suspend(struct device *dev)
> +{
> +	struct hibvt_i2c_dev *i2c = dev_get_drvdata(dev);
> +
> +	i2c_lock_adapter(&i2c->adap);
> +	clk_disable_unprepare(i2c->clk);
> +	i2c_unlock_adapter(&i2c->adap);
> +
> +	return 0;
> +}
> +
> +static int hibvt_i2c_resume(struct device *dev)
> +{
> +	struct hibvt_i2c_dev *i2c = dev_get_drvdata(dev);
> +
> +	i2c_lock_adapter(&i2c->adap);
> +	clk_prepare_enable(i2c->clk);
> +	hibvt_i2c_hw_init(i2c);
> +	i2c_unlock_adapter(&i2c->adap);
> +
> +	return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(hibvt_i2c_dev_pm, hibvt_i2c_suspend,
> +		hibvt_i2c_resume);
> +
> +static const struct of_device_id hibvt_i2c_match[] = {
> +	{ .compatible = "hisilicon,hibvt-i2c"},
> +	{ .compatible = "hisilicon,hi3516cv300-i2c"},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, hibvt_i2c_match);
> +
> +static struct platform_driver hibvt_i2c_driver = {
> +	.driver		= {
> +		.name	= "hibvt-i2c",
> +		.of_match_table = hibvt_i2c_match,
> +		.pm	= &hibvt_i2c_dev_pm,
> +	},
> +	.probe		= hibvt_i2c_probe,
> +	.remove		= hibvt_i2c_remove,
> +};
> +
> +module_platform_driver(hibvt_i2c_driver);
> +
> +MODULE_AUTHOR("Pan Wen, <wenpan@xxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("HISILICON BVT I2C Bus driver");
> +MODULE_LICENSE("GPL v2");
> 

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