[PATCH 6/7] spi: spi-rpc-if: Implement 200ms runtime PM autosuspend delay

[Prabhakar]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

Enable and configure the runtime PM autosuspend infrastructure during
the controller probe sequence to safeguard chunked flash operations.

The underlying hardware controller handles memory-mapped page programming
by dividing data transfers into an automated sequence of consecutive
64-byte chunks. To prevent the power management framework from
aggressively gating the interface between these individual chunk frames
or during immediate out-of-band status checks, an explicit 200ms delay
window is required.

Configure this temporal cushion using pm_runtime_set_autosuspend_delay()
and pm_runtime_use_autosuspend() at probe time, ensuring proper cleanup
via pm_runtime_dont_use_autosuspend() in error and driver removal
pathways. This guarantees interface continuity across the full lifecycle
of a multi-chunk write operation.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
 drivers/spi/spi-rpc-if.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/spi/spi-rpc-if.c b/drivers/spi/spi-rpc-if.c
index b63c7856e758..9a740342d0f7 100644
--- a/drivers/spi/spi-rpc-if.c
+++ b/drivers/spi/spi-rpc-if.c
@@ -161,6 +161,8 @@ static int rpcif_spi_probe(struct platform_device *pdev)
 
 	ctlr->dev.of_node = parent->of_node;
 
+	pm_runtime_set_autosuspend_delay(rpc->dev, 200);
+	pm_runtime_use_autosuspend(rpc->dev);
 	pm_runtime_enable(rpc->dev);
 
 	ctlr->num_chipselect = 1;
@@ -183,6 +185,7 @@ static int rpcif_spi_probe(struct platform_device *pdev)
 	return 0;
 
 out_disable_rpm:
+	pm_runtime_dont_use_autosuspend(rpc->dev);
 	pm_runtime_disable(rpc->dev);
 	return error;
 }
@@ -193,6 +196,7 @@ static void rpcif_spi_remove(struct platform_device *pdev)
 	struct rpcif *rpc = spi_controller_get_devdata(ctlr);
 
 	spi_unregister_controller(ctlr);
+	pm_runtime_dont_use_autosuspend(rpc->dev);
 	pm_runtime_disable(rpc->dev);
 }
 
-- 
2.54.0