[PATCH V3 16/21] i3c: mipi-i3c-hci: Factor out core initialization into helper

[Frank Li]

On Tue, Jan 13, 2026 at 09:26:57AM +0200, Adrian Hunter wrote:
> Prepare for future reuse.  Move core initialization logic from
> i3c_hci_init() into a dedicated helper function,
> i3c_hci_reset_and_init().
>
> Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
> ---
>
>
> Changes in V3:
>
> 	Move I/O mode setting if I/O mode already selected, to a
> 	separate patch
>
> Changes in V2:
>
> 	New patch
>
>
>  drivers/i3c/master/mipi-i3c-hci/core.c | 142 +++++++++++++------------
>  1 file changed, 75 insertions(+), 67 deletions(-)
>
> diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
> index 569c8584045a..8b8e3952d41d 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/core.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/core.c
> @@ -639,6 +639,80 @@ static int i3c_hci_set_io_mode(struct i3c_hci *hci, bool dma)
>  	return 0;
>  }
>
> +static int i3c_hci_reset_and_init(struct i3c_hci *hci)
> +{
> +	u32 regval;
> +	int ret;
> +
> +	ret = i3c_hci_software_reset(hci);
> +	if (ret)
> +		return -ENXIO;
> +
> +	/* Disable all interrupts */
> +	reg_write(INTR_SIGNAL_ENABLE, 0x0);
> +	/*
> +	 * Only allow bit 31:10 signal updates because
> +	 * Bit 0:9 are reserved in IP version >= 0.8
> +	 * Bit 0:5 are defined in IP version < 0.8 but not handled by PIO code
> +	 */
> +	reg_write(INTR_STATUS_ENABLE, GENMASK(31, 10));
> +
> +	/* Make sure our data ordering fits the host's */
> +	regval = reg_read(HC_CONTROL);
> +	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
> +		if (!(regval & HC_CONTROL_DATA_BIG_ENDIAN)) {
> +			regval |= HC_CONTROL_DATA_BIG_ENDIAN;
> +			reg_write(HC_CONTROL, regval);
> +			regval = reg_read(HC_CONTROL);
> +			if (!(regval & HC_CONTROL_DATA_BIG_ENDIAN)) {
> +				dev_err(&hci->master.dev, "cannot set BE mode\n");
> +				return -EOPNOTSUPP;
> +			}
> +		}
> +	} else {
> +		if (regval & HC_CONTROL_DATA_BIG_ENDIAN) {
> +			regval &= ~HC_CONTROL_DATA_BIG_ENDIAN;
> +			reg_write(HC_CONTROL, regval);
> +			regval = reg_read(HC_CONTROL);
> +			if (regval & HC_CONTROL_DATA_BIG_ENDIAN) {
> +				dev_err(&hci->master.dev, "cannot clear BE mode\n");
> +				return -EOPNOTSUPP;
> +			}
> +		}
> +	}
> +
> +	/* 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 (!hci->io) {
> +		dev_err(&hci->master.dev, "neither DMA nor PIO can be used\n");
> +		ret = ret ?: -EINVAL;
> +	}
> +	if (ret)
> +		return ret;
> +
> +	/* Configure OD and PP timings for AMD platforms */
> +	if (hci->quirks & HCI_QUIRK_OD_PP_TIMING)
> +		amd_set_od_pp_timing(hci);
> +
> +	return 0;
> +}
> +
>  static int i3c_hci_init(struct i3c_hci *hci)
>  {
>  	bool size_in_dwords;
> @@ -708,43 +782,6 @@ static int i3c_hci_init(struct i3c_hci *hci)
>  	if (ret)
>  		return ret;
>
> -	ret = i3c_hci_software_reset(hci);
> -	if (ret)
> -		return -ENXIO;
> -
> -	/* Disable all interrupts */
> -	reg_write(INTR_SIGNAL_ENABLE, 0x0);
> -	/*
> -	 * Only allow bit 31:10 signal updates because
> -	 * Bit 0:9 are reserved in IP version >= 0.8
> -	 * Bit 0:5 are defined in IP version < 0.8 but not handled by PIO code
> -	 */
> -	reg_write(INTR_STATUS_ENABLE, GENMASK(31, 10));
> -
> -	/* Make sure our data ordering fits the host's */
> -	regval = reg_read(HC_CONTROL);
> -	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
> -		if (!(regval & HC_CONTROL_DATA_BIG_ENDIAN)) {
> -			regval |= HC_CONTROL_DATA_BIG_ENDIAN;
> -			reg_write(HC_CONTROL, regval);
> -			regval = reg_read(HC_CONTROL);
> -			if (!(regval & HC_CONTROL_DATA_BIG_ENDIAN)) {
> -				dev_err(&hci->master.dev, "cannot set BE mode\n");
> -				return -EOPNOTSUPP;
> -			}
> -		}
> -	} else {
> -		if (regval & HC_CONTROL_DATA_BIG_ENDIAN) {
> -			regval &= ~HC_CONTROL_DATA_BIG_ENDIAN;
> -			reg_write(HC_CONTROL, regval);
> -			regval = reg_read(HC_CONTROL);
> -			if (regval & HC_CONTROL_DATA_BIG_ENDIAN) {
> -				dev_err(&hci->master.dev, "cannot clear BE mode\n");
> -				return -EOPNOTSUPP;
> -			}
> -		}
> -	}
> -
>  	/* Select our command descriptor model */
>  	switch (FIELD_GET(HC_CAP_CMD_SIZE, hci->caps)) {
>  	case 0:
> @@ -762,36 +799,7 @@ static int i3c_hci_init(struct i3c_hci *hci)
>  	if (hci->quirks & HCI_QUIRK_PIO_MODE)
>  		hci->RHS_regs = NULL;

these parts have not move into helper funciton.  Is it safe to use
"hci->RHS_regs" in helper funciton?

Frank

>
> -	/* 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 (!hci->io) {
> -		dev_err(&hci->master.dev, "neither DMA nor PIO can be used\n");
> -		if (!ret)
> -			ret = -EINVAL;
> -		return ret;
> -	}
> -
> -	/* Configure OD and PP timings for AMD platforms */
> -	if (hci->quirks & HCI_QUIRK_OD_PP_TIMING)
> -		amd_set_od_pp_timing(hci);
> -
> -	return 0;
> +	return i3c_hci_reset_and_init(hci);
>  }
>
>  static int i3c_hci_probe(struct platform_device *pdev)
> --
> 2.51.0
>
>
> --
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