linux-drivers/
drivers/mmc/host

MMC, SD, SDIO, and eMMC host controllers

Host-side drivers that let Linux talk to SD cards, microSD cards, eMMC flash, and SDIO peripherals, covering the generic SDHCI standard plus vendor controllers from Qualcomm, Rockchip, STMicroelectronics, Synopsys, Sunplus, and many other SoC makers. They are present in nearly every laptop with an SD slot, every Android phone, and most embedded boards shipping today.

keep conf=0.95 deploy=high replacement=none subsystem=mmc category=storage-mmc-sd
95%

recommendation

It should stay because this is an active, broadly-deployed subsystem rather than a single legacy driver, and current SoC vendors are still submitting patches against it, including 2026 work on LiteX, Synopsys DWC MSHC, and Qualcomm sdhci-msm. New hardware using these interfaces ships every year, so there is no plausible replacement for the directory as a whole.

repository signals

130 files
110,124 source lines
1,153 commits, 5y
+20,892 / −10,129 lines added / removed, 5y
282 authors, 5y
monthly commits · 2021-04-21 → 2026-04-21 · 1,153 total · active in 60/61 months
2021 2022 2023 2024 2025 2026 2021-04: 9 commits · +25 −30 2021-05: 18 commits · +116 −66 2021-06: 27 commits · +185 −48 2021-07: 7 commits · +283 −101 2021-08: 23 commits · +187 −60 2021-09: 22 commits · +245 −66 2021-10: 29 commits · +423 −336 2021-11: 25 commits · +211 −183 2021-12: 30 commits · +594 −330 2022-01: 11 commits · +822 −34 2022-02: 11 commits · +35 −70 2022-03: 20 commits · +225 −107 2022-04: 25 commits · +216 −79 2022-05: 13 commits · +285 −62 2022-06: 20 commits · +165 −120 2022-07: 13 commits · +125 −83 2022-08: 9 commits · +97 −37 2022-09: 19 commits · +174 −2,138 2022-10: 40 commits · +312 −439 2022-11: 45 commits · +1,339 −165 2022-12: 15 commits · +169 −42 2023-01: 19 commits · +294 −48 2023-02: 16 commits · +284 −101 2023-03: 20 commits · +191 −138 2023-04: 9 commits · +451 −197 2023-05: 8 commits · +75 −22 2023-06: 42 commits · +961 −192 2023-07: 67 commits · +182 −300 2023-08: 35 commits · +685 −284 2023-09: 11 commits · +115 −116 2023-10: 8 commits · +130 −60 2023-11: 14 commits · +524 −85 2023-12: 8 commits · +150 −241 2024-01: 11 commits · +348 −197 2024-02: 23 commits · +528 −94 2024-03: 26 commits · +421 −117 2024-04: 21 commits · +381 −249 2024-05: 4 commits · +90 −23 2024-06: 12 commits · +150 −115 2024-07: 13 commits · +520 −152 2024-08: 14 commits · +558 −197 2024-09: 12 commits · +256 −196 2024-10: 32 commits · +2,407 −216 2024-11: 13 commits · +110 −39 2024-12: 7 commits · +136 −58 2025-01: 7 commits · +94 −112 2025-02: 6 commits · +177 −12 2025-03: 16 commits · +405 −107 2025-04: 18 commits · +195 −98 2025-05: 14 commits · +572 −207 2025-06: 94 commits · +1,517 −832 2025-07: 15 commits · +146 −52 2025-08: 50 commits · +304 −307 2025-09: 9 commits · +117 −36 2025-10: 12 commits · +766 −84 2025-11: 19 commits · +277 −219 2025-12: 4 commits · +51 −3 2026-01: 5 commits · +46 −2 2026-02: 3 commits · +15 −16 2026-03: 4 commits · +29 −8 2026-04: 0 commits · +0 −0

sources

  1. lore.kernel.org

    Recent 2026 upstream patch against drivers/mmc/host (litex_mmc), showing active maintenance.

  2. lore.kernel.org

    Recent 2026 upstream patch for sdhci-of-dwcmshc suspend/resume support, indicating ongoing enablement for current Synopsys-based hosts.

  3. lore.kernel.org

    Recent 2026 upstream fix for Qualcomm sdhci-msm, showing active vendor-backed maintenance on contemporary SoCs.

  4. git.kernel.org

    The directory is the kernel's MMC/SD/SDIO host-controller driver collection, including generic SDHCI plus current vendor SoC controllers such as Sunplus SP7021 and STM32 SDMMC.

codex reasoning notes (technical)

Keep: this is a large, active subsystem directory rather than a stale single-chip driver. Recent lore evidence was obtained with mcp__lore_http__.lore_regex over patch diffs touching drivers/mmc/host in linux-mmc; it returned April 2026 patches for LiteX, Synopsys DWC MSHC, Qualcomm MSM, and Rockchip-related DW MMC code. Kconfig context was obtained from a local shell read of drivers/mmc/host/Kconfig, with the stable git.kernel.org tree URL cited by canonical recall. Given ongoing upstream traffic across multiple current SoC vendors and the broad MMC/eMMC/SD deployment base in embedded and laptop hardware, deployments remain high and there is no single replacement driver for the directory as a whole.