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In the LAN966x PCI device use case, syscon cannot be used as syscon
devices do not support removal [1]. A syscon device is a core
"system"
device and not a device available in some addon boards and so, it is
not
supposed to be removed.

In order to remove the syscon usage, use a local mapping of a reg
address range when cpu-syscon is not present.

Link:
https://lore.kernel.org/all/20240923100741.11277439@bootlin.com/ (local) [1]
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 drivers/reset/reset-microchip-sparx5.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/reset/reset-microchip-sparx5.c

b/drivers/reset/reset-microchip-sparx5.c
index 636e85c388b0..1c095fa41d69 100644

--- a/drivers/reset/reset-microchip-sparx5.c
+++ b/drivers/reset/reset-microchip-sparx5.c

@@ -114,8 +114,22 @@ static int mchp_sparx5_reset_probe(struct

platform_device *pdev)
                return -ENOMEM;

        err = mchp_sparx5_map_syscon(pdev, "cpu-syscon", &ctx-

quoted

cpu_ctrl);

-       if (err)
+       switch (err) {
+       case 0:
+               break;
+       case -ENODEV:
+               /*
+                * The cpu-syscon device is not available.
+                * Fall back with IO mapping (i.e. mapping from reg
property).
+                */
+               err = mchp_sparx5_map_io(pdev, 1, &ctx->cpu_ctrl);
+               if (err)
+                       return err;
+               break;
+       default:
                return err;
+       }
+
        err = mchp_sparx5_map_io(pdev, 0, &ctx->gcb_ctrl);
        if (err)
                return err;
--
2.46.1