From: Adrian Hunter <adrian.hunter@intel.com>
Date: Tue, 13 Jan 2026 07:26:52 +0000 (+0200)
Subject: i3c: mipi-i3c-hci: Add DMA suspend and resume support
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8169587204431ce23df9522c2e859b5238934c42;p=thirdparty%2Fkernel%2Flinux.git

i3c: mipi-i3c-hci: Add DMA suspend and resume support

Introduce helper functions to suspend and resume DMA operations.  These
are required to prepare for upcoming Runtime PM support, ensuring that
DMA state is properly managed during power transitions.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260113072702.16268-12-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---

diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index 9ed69da529777..2e5b4974d431e 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -275,6 +275,29 @@ static void hci_dma_init_rings(struct i3c_hci *hci)
 		hci_dma_init_rh(hci, &rings->headers[i], i);
 }
 
+static void hci_dma_suspend(struct i3c_hci *hci)
+{
+	struct hci_rings_data *rings = hci->io_data;
+	int n = rings ? rings->total : 0;
+
+	for (int i = 0; i < n; i++) {
+		struct hci_rh_data *rh = &rings->headers[i];
+
+		rh_reg_write(INTR_SIGNAL_ENABLE, 0);
+		rh_reg_write(RING_CONTROL, 0);
+	}
+
+	i3c_hci_sync_irq_inactive(hci);
+}
+
+static void hci_dma_resume(struct i3c_hci *hci)
+{
+	struct hci_rings_data *rings = hci->io_data;
+
+	if (rings)
+		hci_dma_init_rings(hci);
+}
+
 static int hci_dma_init(struct i3c_hci *hci)
 {
 	struct hci_rings_data *rings;
@@ -865,4 +888,6 @@ const struct hci_io_ops mipi_i3c_hci_dma = {
 	.request_ibi		= hci_dma_request_ibi,
 	.free_ibi		= hci_dma_free_ibi,
 	.recycle_ibi_slot	= hci_dma_recycle_ibi_slot,
+	.suspend		= hci_dma_suspend,
+	.resume			= hci_dma_resume,
 };
diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
index aa8a03594e644..38f927685d3b1 100644
--- a/drivers/i3c/master/mipi-i3c-hci/hci.h
+++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
@@ -125,6 +125,8 @@ struct hci_io_ops {
 				struct i3c_ibi_slot *slot);
 	int (*init)(struct i3c_hci *hci);
 	void (*cleanup)(struct i3c_hci *hci);
+	void (*suspend)(struct i3c_hci *hci);
+	void (*resume)(struct i3c_hci *hci);
 };
 
 extern const struct hci_io_ops mipi_i3c_hci_pio;