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

[Adrian Hunter <adrian.hunter@intel.com>]

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_restore_daa() helper which additionally handles the case where
devices are assigned different dynamic addresses after a hibernation boot.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/i3c/master/mipi-i3c-hci/core.c | 53 ++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index 02c5a133e329..b972d8bc81e6 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -769,6 +769,53 @@ 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;
+
+	if (restore)
+		ret = i3c_master_restore_daa(&hci->master);
+	else
+		ret = i3c_master_do_daa(&hci->master);
+
+	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 +992,12 @@ 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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