Re: [PATCH] i2c: imx: add support for I2C_M_STOP flag

From: Andi Shyti
Date: Thu Jul 27 2023 - 16:31:05 EST


Hi Mans,

on top of Oleksij's comments...

[...]

> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -1262,10 +1262,17 @@ static int i2c_imx_xfer_common(struct i2c_adapter *adapter,
>
> /* read/write data */
> for (i = 0; i < num; i++) {
> - if (i == num - 1)
> - is_lastmsg = true;
> + if (is_lastmsg) {
> + /* previous message had I2C_M_STOP flag set */
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> + temp |= I2CR_MSTA;
> + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> + result = i2c_imx_bus_busy(i2c_imx, 1, atomic);
> + if (result)
> + goto fail0;
> + }
>
> - if (i) {
> + if (i && !is_lastmsg) {

} else if (i) {

looks a bit simplier to me.

> dev_dbg(&i2c_imx->adapter.dev,
> "<%s> repeated start\n", __func__);
> temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> @@ -1275,6 +1282,10 @@ static int i2c_imx_xfer_common(struct i2c_adapter *adapter,
> if (result)
> goto fail0;
> }
> +
> + if (i == num - 1 || (msgs[i].flags & I2C_M_STOP))
> + is_lastmsg = true;

you don't need this "i == num - 1" here.

Andi

> dev_dbg(&i2c_imx->adapter.dev,
> "<%s> transfer message: %d\n", __func__, i);
> /* write/read data */