Re: [PATCH 2/2] i2c: hisi: Add clearing tx aempty interrupt operation

[Yicong Yang <yangyicong@huawei.com>]

On 2024/1/23 16:02, Devyn Liu wrote:
> The driver receives the tx fifo almost empty(aempty) interrupt and
> reads the tx_aempty_int_mstat to start a round of data transfer.
> The operation of clearing the TX aempty interrupt after completing
> a write cycle is added to ensure that the FIFO is truly at almost
> empty status when an aempty interrupt is received.
> The threshold for fifo almost empty interrupt is defined as 1.
> 
> Signed-off-by: Devyn Liu <liudingyuan@huawei.com>

Reviewed-by: Yicong Yang <yangyicong@hisilicon.com>

> ---
>  drivers/i2c/busses/i2c-hisi.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-hisi.c b/drivers/i2c/busses/i2c-hisi.c
> index 82a0c739aae4..08f6f97722a8 100644
> --- a/drivers/i2c/busses/i2c-hisi.c
> +++ b/drivers/i2c/busses/i2c-hisi.c
> @@ -57,6 +57,8 @@
>  #define   HISI_I2C_FS_SPK_LEN_CNT	GENMASK(7, 0)
>  #define HISI_I2C_HS_SPK_LEN		0x003c
>  #define   HISI_I2C_HS_SPK_LEN_CNT	GENMASK(7, 0)
> +#define HISI_I2C_TX_INT_CLR		0x0040
> +#define   HISI_I2C_TX_AEMPTY_INT		BIT(0)
>  #define HISI_I2C_INT_MSTAT		0x0044
>  #define HISI_I2C_INT_CLR		0x0048
>  #define HISI_I2C_INT_MASK		0x004C
> @@ -124,6 +126,11 @@ static void hisi_i2c_clear_int(struct hisi_i2c_controller *ctlr, u32 mask)
>  	writel_relaxed(mask, ctlr->iobase + HISI_I2C_INT_CLR);
>  }
>  
> +static void hisi_i2c_clear_tx_int(struct hisi_i2c_controller *ctlr, u32 mask)
> +{
> +	writel_relaxed(mask, ctlr->iobase + HISI_I2C_TX_INT_CLR);
> +}
> +
>  static void hisi_i2c_handle_errors(struct hisi_i2c_controller *ctlr)
>  {
>  	u32 int_err = ctlr->xfer_err, reg;
> @@ -168,6 +175,7 @@ static int hisi_i2c_start_xfer(struct hisi_i2c_controller *ctlr)
>  	writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL);
>  
>  	hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL);
> +	hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT);
>  	hisi_i2c_enable_int(ctlr, HISI_I2C_INT_ALL);
>  
>  	return 0;
> @@ -323,6 +331,8 @@ static void hisi_i2c_xfer_msg(struct hisi_i2c_controller *ctlr)
>  	 */
>  	if (ctlr->msg_tx_idx == ctlr->msg_num)
>  		hisi_i2c_disable_int(ctlr, HISI_I2C_INT_TX_EMPTY);
> +
> +	hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT);
>  }
>  
>  static irqreturn_t hisi_i2c_irq(int irq, void *context)
> @@ -363,6 +373,7 @@ static irqreturn_t hisi_i2c_irq(int irq, void *context)
>  	if (int_stat & HISI_I2C_INT_TRANS_CPLT) {
>  		hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
>  		hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL);
> +		hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT);
>  		complete(ctlr->completion);
>  	}
>  
>