From b333d4c703b30cabcb7d3e5fd4c5a830eadcf8a9 Mon Sep 17 00:00:00 2001
From: Larry Bernstone <lbernstone@gmail.com>
Date: Mon, 17 Nov 2025 11:59:43 -1000
Subject: [PATCH] feat(sd_mmc): Make UHS-I SDR the default for ESP-P4 SD_MMC

---
 libraries/SD_MMC/src/SD_MMC.cpp | 4 ++++
 libraries/SD_MMC/src/SD_MMC.h   | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/libraries/SD_MMC/src/SD_MMC.cpp b/libraries/SD_MMC/src/SD_MMC.cpp
index 12ab2b565eb..a76377d321d 100644
--- a/libraries/SD_MMC/src/SD_MMC.cpp
+++ b/libraries/SD_MMC/src/SD_MMC.cpp
@@ -246,6 +246,10 @@ bool SDMMCFS::begin(const char *mountpoint, bool mode1bit, bool format_if_mount_
     .width = 4,
     .flags = 0,
   };
+#ifdef SOC_SDMMC_UHS_I_SUPPORTED
+  host.flags &= ~SDMMC_HOST_FLAG_DDR;
+  slot_config.flags = SDMMC_SLOT_FLAG_UHS1;
+#endif
 #else
   host.slot = SDMMC_HOST_SLOT_1;
 #endif
diff --git a/libraries/SD_MMC/src/SD_MMC.h b/libraries/SD_MMC/src/SD_MMC.h
index 7192d466b89..e20c6ccfaa9 100644
--- a/libraries/SD_MMC/src/SD_MMC.h
+++ b/libraries/SD_MMC/src/SD_MMC.h
@@ -30,8 +30,12 @@
 // you can define BOARD_MAX_SDMMC_FREQ with lower value (Ex. SDMMC_FREQ_DEFAULT)
 // in pins_arduino.h for your board variant.
 #ifndef BOARD_MAX_SDMMC_FREQ
+#ifdef SOC_SDMMC_UHS_I_SUPPORTED
+#define BOARD_MAX_SDMMC_FREQ SDMMC_FREQ_SDR50
+#else
 #define BOARD_MAX_SDMMC_FREQ SDMMC_FREQ_HIGHSPEED
 #endif
+#endif
 
 namespace fs {