Re: [PATCH] i3c: dw: Add shutdown support to dw_i3c_master driver

[Frank Li]

On Mon, Jul 28, 2025 at 04:14:25PM +0530, Manikanta Guntupalli wrote:
> Add shutdown handler to the Synopsys DesignWare I3C master driver,
> ensuring the device is gracefully disabled during system shutdown.
>
> The shutdown handler cancels any pending hot-join work and disables
> interrupts.
>
> Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@xxxxxxx>
> ---
>  drivers/i3c/master/dw-i3c-master.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
> index ae1992665673..6769def5580a 100644
> --- a/drivers/i3c/master/dw-i3c-master.c
> +++ b/drivers/i3c/master/dw-i3c-master.c
> @@ -1762,6 +1762,29 @@ static const struct dev_pm_ops dw_i3c_pm_ops = {
>  	SET_RUNTIME_PM_OPS(dw_i3c_master_runtime_suspend, dw_i3c_master_runtime_resume, NULL)
>  };
>
> +static void dw_i3c_shutdown(struct platform_device *pdev)
> +{
> +	struct dw_i3c_master *master = platform_get_drvdata(pdev);
> +	int ret;
> +
> +	ret = pm_runtime_resume_and_get(master->dev);
> +	if (ret < 0) {
> +		dev_err(master->dev,
> +			"<%s> cannot resume i3c bus master, err: %d\n",
> +			__func__, ret);
> +		return;
> +	}
> +
> +	cancel_work_sync(&master->hj_work);
> +
> +	/* Disable interrupts */
> +	writel((u32)~INTR_ALL, master->regs + INTR_STATUS_EN);
> +	writel((u32)~INTR_ALL, master->regs + INTR_SIGNAL_EN);
> +
> +	pm_runtime_mark_last_busy(master->dev);

Needn't call pm_runtime_mark_last_busy() now

See: https://lore.kernel.org/linux-pm/20250704075225.3212486-1-sakari.ailus@xxxxxxxxxxxxxxx/

Frank
> +	pm_runtime_put_autosuspend(master->dev);
> +}
> +
>  static const struct of_device_id dw_i3c_master_of_match[] = {
>  	{ .compatible = "snps,dw-i3c-master-1.00a", },
>  	{},
> @@ -1777,6 +1800,7 @@ MODULE_DEVICE_TABLE(acpi, amd_i3c_device_match);
>  static struct platform_driver dw_i3c_driver = {
>  	.probe = dw_i3c_probe,
>  	.remove = dw_i3c_remove,
> +	.shutdown = dw_i3c_shutdown,
>  	.driver = {
>  		.name = "dw-i3c-master",
>  		.of_match_table = dw_i3c_master_of_match,
> --
> 2.34.1
>