[PATCH v2 01/10] EDAC/ie31200: Decouple DIMM width decoding from enum order

The current method to get DIMM width relied on DEV_* enum ordering via a
linear offset (+ DEV_X8), tightly coupling hardware encoding to enum layout.

Replace it with explicit decoding to remove this dependency, as the
enum is expected to grow with additional device widths.

Signed-off-by: Qiuxu Zhuo <[email protected]>
---
 drivers/edac/ie31200_edac.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/edac/ie31200_edac.c b/drivers/edac/ie31200_edac.c
index e3bd6436669b..bfd54012ae47 100644
--- a/drivers/edac/ie31200_edac.c
+++ b/drivers/edac/ie31200_edac.c
@@ -416,7 +416,23 @@ static void populate_dimm_info(struct dimm_data *dd, u32 addr_decode, int dimm,
 {
 	dd->size = field_get(cfg->reg_mad_dimm_size_mask[dimm], addr_decode) * cfg->reg_mad_dimm_size_granularity;
 	dd->ranks = field_get(cfg->reg_mad_dimm_rank_mask[dimm], addr_decode) + 1;
-	dd->dtype = field_get(cfg->reg_mad_dimm_width_mask[dimm], addr_decode) + DEV_X8;
+
+	switch (field_get(cfg->reg_mad_dimm_width_mask[dimm], addr_decode)) {
+	case 0:
+		dd->dtype = DEV_X8;
+		break;
+	case 1:
+		dd->dtype = DEV_X16;
+		break;
+	case 2:
+		dd->dtype = DEV_X32;
+		break;
+	case 3:
+		dd->dtype = DEV_X64;
+		break;
+	default:
+		dd->dtype = DEV_UNKNOWN;
+	}
 }
 
 static void ie31200_get_dimm_config(struct mem_ctl_info *mci, void __iomem *window,
-- 
2.43.0