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

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Revision as of 02:00, 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...")
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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