[PATCH V2 2/3] i3c: mipi-i3c-hci: Add optional System Suspend support

[Frank Li]

On Mon, Jan 19, 2026 at 12:02:11PM +0200, Adrian Hunter wrote:
> Add system suspend callbacks.  Implement them by forcing runtime PM.
> Consequently bail out if Runtime PM is not allowed.
>
> On resume from System Suspend (suspend to RAM), rerun Dynamic Address
> Assignment to restore addresses for devices that may have lost power.
>
> On resume from System Hibernation (suspend to disk), use the new
> i3c_master_do_daa_ext() helper with 'restore' set to true, which
> additionally handles the case where devices are assigned different dynamic
> addresses after a hibernation boot.
>
> Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
> ---

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

>
>
> Changes in V2:
>
> 	Helper function is now called i3c_master_do_daa_ext() and takes
> 	'restore' as an argument
>
>
>  drivers/i3c/master/mipi-i3c-hci/core.c | 49 ++++++++++++++++++++++++++
>  1 file changed, 49 insertions(+)
>
> diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
> index 02c5a133e329..ac8cfec1ff9e 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/core.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/core.c
> @@ -769,6 +769,49 @@ static int i3c_hci_runtime_resume(struct device *dev)
>  	return 0;
>  }
>
> +static int i3c_hci_suspend(struct device *dev)
> +{
> +	struct i3c_hci *hci = dev_get_drvdata(dev);
> +
> +	if (!(hci->quirks & HCI_QUIRK_RPM_ALLOWED))
> +		return 0;
> +
> +	return pm_runtime_force_suspend(dev);
> +}
> +
> +static int i3c_hci_resume_common(struct device *dev, bool restore)
> +{
> +	struct i3c_hci *hci = dev_get_drvdata(dev);
> +	int ret;
> +
> +	if (!(hci->quirks & HCI_QUIRK_RPM_ALLOWED))
> +		return 0;
> +
> +	ret = pm_runtime_force_resume(dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = i3c_master_do_daa_ext(&hci->master, restore);
> +	if (ret)
> +		dev_err(dev, "Dynamic Address Assignment failed on resume, error %d\n", ret);
> +
> +	/*
> +	 * I3C devices may have retained their dynamic address anyway. Do not
> +	 * fail the resume because of DAA error.
> +	 */
> +	return 0;
> +}
> +
> +static int i3c_hci_resume(struct device *dev)
> +{
> +	return i3c_hci_resume_common(dev, false);
> +}
> +
> +static int i3c_hci_restore(struct device *dev)
> +{
> +	return i3c_hci_resume_common(dev, true);
> +}
> +
>  #define DEFAULT_AUTOSUSPEND_DELAY_MS 1000
>
>  static void i3c_hci_rpm_enable(struct device *dev)
> @@ -945,6 +988,12 @@ static const struct platform_device_id i3c_hci_driver_ids[] = {
>  MODULE_DEVICE_TABLE(platform, i3c_hci_driver_ids);
>
>  static const struct dev_pm_ops i3c_hci_pm_ops = {
> +	.suspend  = pm_sleep_ptr(i3c_hci_suspend),
> +	.resume   = pm_sleep_ptr(i3c_hci_resume),
> +	.freeze   = pm_sleep_ptr(i3c_hci_suspend),
> +	.thaw     = pm_sleep_ptr(i3c_hci_resume),
> +	.poweroff = pm_sleep_ptr(i3c_hci_suspend),
> +	.restore  = pm_sleep_ptr(i3c_hci_restore),
>  	RUNTIME_PM_OPS(i3c_hci_runtime_suspend, i3c_hci_runtime_resume, NULL)
>  };
>
> --
> 2.51.0
>
>
> --
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