[PATCH V2 14/20] i3c: mipi-i3c-hci: Factor out software reset into helper

[Frank Li]

On Thu, Jan 08, 2026 at 10:05:52AM +0200, Adrian Hunter wrote:
> Prepare for future reuse of the reset sequence in other contexts, such as
> power management.  Move the software reset logic from i3c_hci_init() into a
> dedicated helper function, i3c_hci_software_reset().
>
> Software reset should never fail.  Print an error message if it does.
>
> Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
> ---

Reviewed-by: Frank Li <Frank.Li at nxp.com>

>
>
> Changes in V2:
>
> 	Add to the commit message a sentence about additional error message
> 	when a timeout happens
>
>
>  drivers/i3c/master/mipi-i3c-hci/core.c | 41 ++++++++++++++++++--------
>  1 file changed, 29 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
> index c4b249fde764..3b0609cb7da7 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/core.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/core.c
> @@ -585,6 +585,34 @@ static irqreturn_t i3c_hci_irq_handler(int irq, void *dev_id)
>  	return result;
>  }
>
> +static int i3c_hci_software_reset(struct i3c_hci *hci)
> +{
> +	u32 regval;
> +	int ret;
> +
> +	/*
> +	 * SOFT_RST must be clear before we write to it.
> +	 * Then we must wait until it clears again.
> +	 */
> +	ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
> +				 !(regval & SOFT_RST), 0, 10 * USEC_PER_MSEC);
> +	if (ret) {
> +		dev_err(&hci->master.dev, "%s: Software reset stuck\n", __func__);
> +		return ret;
> +	}
> +
> +	reg_write(RESET_CONTROL, SOFT_RST);
> +
> +	ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
> +				 !(regval & SOFT_RST), 0, 10 * USEC_PER_MSEC);
> +	if (ret) {
> +		dev_err(&hci->master.dev, "%s: Software reset failed\n", __func__);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  static int i3c_hci_init(struct i3c_hci *hci)
>  {
>  	bool size_in_dwords, mode_selector;
> @@ -654,18 +682,7 @@ static int i3c_hci_init(struct i3c_hci *hci)
>  	if (ret)
>  		return ret;
>
> -	/*
> -	 * Now let's reset the hardware.
> -	 * SOFT_RST must be clear before we write to it.
> -	 * Then we must wait until it clears again.
> -	 */
> -	ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
> -				 !(regval & SOFT_RST), 1, 10000);
> -	if (ret)
> -		return -ENXIO;
> -	reg_write(RESET_CONTROL, SOFT_RST);
> -	ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
> -				 !(regval & SOFT_RST), 1, 10000);
> +	ret = i3c_hci_software_reset(hci);
>  	if (ret)
>  		return -ENXIO;
>
> --
> 2.51.0
>
>
> --
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