R-Car/Use-GPIO-for-SD-card-detection

From eLinux.org
< R-Car
Revision as of 03:00, 26 April 2021 by Shimoda (talk | contribs) (Created page with "== Overview == R-Car boards use GPIO for SD card detection, not use built-in card detection pin, because we have some reasons: * Old Renesas SoCs don't have built-in card de...")
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Overview

R-Car boards use GPIO for SD card detection, not use built-in card detection pin, because we have some reasons:

  • Old Renesas SoCs don't have built-in card detection pin.
    • So, for consistency and reliability, we use GPIO for SD card detection on R-Car boards.
  • Using GPIO is an advantage for power management (clock gating and/or power domain) of SDHI modules.
    • If we use built-in card detection pin, we have to turn the SDHI module on anyway.

Remarks

The TMIO core supports built-in card detection by using the following commits.

c7cd630a9751 mmc: tmio: fix never-detected card insertion bug
497d1f965c20 mmc: tmio: support IP-builtin card detection logic