[PATCH V3 17/21] i3c: mipi-i3c-hci: Allow core re-initialization for Runtime PM support

[Frank Li]

On Tue, Jan 13, 2026 at 09:26:58AM +0200, Adrian Hunter wrote:
> Prepare i3c_hci_reset_and_init() to support runtime resume.  Update it to
> handle the case where the I/O mode has already been selected.
>
> Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
> ---

Reviewed-by: Frank Li <Frank.Li at nxp.com>
>
>
> Changes in V3
>
> 	New patch
>
>
>  drivers/i3c/master/mipi-i3c-hci/core.c | 38 ++++++++++++++------------
>  1 file changed, 21 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
> index 8b8e3952d41d..fc0a47a36961 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/core.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/core.c
> @@ -681,27 +681,31 @@ static int i3c_hci_reset_and_init(struct i3c_hci *hci)
>  		}
>  	}
>
> -	/* Try activating DMA operations first */
> -	if (hci->RHS_regs) {
> -		ret = i3c_hci_set_io_mode(hci, true);
> -		if (!ret) {
> -			hci->io = &mipi_i3c_hci_dma;
> -			dev_dbg(&hci->master.dev, "Using DMA\n");
> +	if (hci->io) {
> +		ret = i3c_hci_set_io_mode(hci, hci->io == &mipi_i3c_hci_dma);
> +	} else {
> +		/* Try activating DMA operations first */
> +		if (hci->RHS_regs) {
> +			ret = i3c_hci_set_io_mode(hci, true);
> +			if (!ret) {
> +				hci->io = &mipi_i3c_hci_dma;
> +				dev_dbg(&hci->master.dev, "Using DMA\n");
> +			}
>  		}
> -	}
>
> -	/* If no DMA, try PIO */
> -	if (!hci->io && hci->PIO_regs) {
> -		ret = i3c_hci_set_io_mode(hci, false);
> -		if (!ret) {
> -			hci->io = &mipi_i3c_hci_pio;
> -			dev_dbg(&hci->master.dev, "Using PIO\n");
> +		/* If no DMA, try PIO */
> +		if (!hci->io && hci->PIO_regs) {
> +			ret = i3c_hci_set_io_mode(hci, false);
> +			if (!ret) {
> +				hci->io = &mipi_i3c_hci_pio;
> +				dev_dbg(&hci->master.dev, "Using PIO\n");
> +			}
>  		}
> -	}
>
> -	if (!hci->io) {
> -		dev_err(&hci->master.dev, "neither DMA nor PIO can be used\n");
> -		ret = ret ?: -EINVAL;
> +		if (!hci->io) {
> +			dev_err(&hci->master.dev, "neither DMA nor PIO can be used\n");
> +			ret = ret ?: -EINVAL;
> +		}
>  	}
>  	if (ret)
>  		return ret;
> --
> 2.51.0
>
>
> --
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