[PATCH 10/30] mci: respect no-1-8-v OF property

Ahmad Fatoum a.fatoum at pengutronix.de
Mon May 5 05:06:13 PDT 2025


no-1-8-v is much more relevant to SD-Cards, but on the off-chance that
is' set on an eMMC node, we should respect it and disable 1.8V speed
modes accordingly.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 drivers/mci/mci-core.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c
index f416998f39b2..bd538ccb4a79 100644
--- a/drivers/mci/mci-core.c
+++ b/drivers/mci/mci-core.c
@@ -3093,6 +3093,17 @@ void mci_of_parse_node(struct mci_host *host,
 		if (of_property_read_bool(np, "no-mmc-hs400"))
 			host->caps2 &= ~(MMC_CAP2_HS400_1_8V | MMC_CAP2_HS400_1_2V |
 					 MMC_CAP2_HS400_ES);
+		if (of_property_read_bool(np, "no-1-8-v")) {
+			/*
+			 * The SDHCI controller in a SoC might support HS200/HS400
+			 * (indicated using mmc-hs200-1_8v/mmc-hs400-1_8v dt property),
+			 * but if the board is modeled such that the IO lines are not
+			 * connected to 1.8v then HS200/HS400 cannot be supported.
+			 * Disable HS200/HS400 if the board does not have 1.8v connected
+			 * to the IO lines. (Applicable for other modes in 1.8v)
+			 */
+			host->caps2 &= ~(MMC_CAP2_HSX00_1_8V | MMC_CAP2_HS400_ES);
+		}
 	}
 }
 
-- 
2.39.5




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