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user/bsps: Add STM32H7 SDMMC driver

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Update #4372
This commit is contained in:
Christian Mauderer 2021-03-19 15:27:21 +01:00
parent 998f8755e0
commit 20893c5cfd
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user/bsps/arm/stm32h7.rst
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@ -47,3 +47,29 @@ USB Host Driver
---------------
The USB host driver ``dwc_otg`` is provided by the ``libbsd``.
SD/MMC Driver
-------------
The SDMMC driver ``st_sdmmc`` is provided by the ``libbsd``.
The default initialization is done for the STM32H743I-EVAL 2 board.
To use different pins, you can create a ``HAL_SD_MspInit()`` function in your
application that overwrites the default one defined in ``RTEMS``. If you don't
have direction lines like on the evaluation board, you can just skip
initializing these pins.
If you want to use a different number of data lines, another polarity for the
data direction pins, a different voltage or similar, you have to redefine
``st_sdmmc_get_config()`` (normally provided by ``libbsd``) in your application.
Known limitations:
* Currently 1.8V signaling is not implemented. Therefore higher speeds like used
for UHS cards are not available. All cards fall back to High Speed transfers.
* The driver uses the IDMA only. MDMA is currently not implemented. For SDMMC1
that means that the memory buffers can only come from AXI SRAM, QSPI memory,
Flash or the FMC (SDRAM, ...). The internal SRAM1, SRAM2, SRAM3 and SRAM4 is
not supported. SDMMC2 should not have that limitation. See ST AN5200 "Getting
started with STM32H7 Series SDMMC host controller" for more details.