Since a85ffa8, `struct sd_card.card_buffer` has naturally fallen at an
offset that is unaligned. This meant that on systems without support for
unaligned access (e.g: Cortex-M0), a hard fault would present when
executing code that casts the buffer to `uint32_t` (such as
`sdmmc_spi_read_cxd()`, `card_query_written()`, etc...)
Historically, it appears that the alignment of the `card_buffer` member
was good and operational only by chance.
Altering the default value of `CONFIG_SDHC_BUFFER_ALIGNMENT` was
rejected, as this has wider implications.
Fixes#62619
Signed-off-by: Attie Grande <attie.grande@argentum-systems.co.uk>
The current implementation uses both, host and card capabilites to derive
the maximum bus width to be used. However, in cases where a MMC device is
not connected to the host via shdc using the full bus width of 8 lines,
device initialization fails. Introducing the `bus-width` property
circumvents this by reducing the host bus capabilites and forcing
communication with the MMC device using 1, 4 or 8 lines.
Signed-off-by: Mourad Kharrazi <mourad.kharrazi@ithinx.io>
Clean up sizes of some SD data fields, as the max value of these fields
is limited by the SD specification
Specifically, the limits are as follows:
num_io: 0-7, 3 bits (SDIO only)
relative_addr: 16 bits (SDMMC/MMC)
block_size: 12 bits (Max of 2KB, uint16_t used)
sd_version: 8 bits (currently at version 3)
card_speed: 8 bits (could potentially be reduced in size)
Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>
- Adds the declaration of the MMC API
- Adds MMC spec related declarations
- Adds some properties to sdhc dts binding for mmc
Signed-off-by: Declan Snyder <declan.snyder@nxp.com>
Add SD subsystem headers. SD subsystem contains generic header for SD
initialization, and headers for SDIO and SDMMC cards.
Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>
