SDHCI(4) | Device Drivers Manual | SDHCI(4) |
NAME¶
sdhci
— PCI SD
Host Controller bridge driver
SYNOPSIS¶
To compile this driver into the kernel, place the following lines in your kernel configuration file:
device mmc
device mmcsd
device sdhci
Alternatively, to load the driver as a module at boot time, place the following lines in loader.conf(5):
mmc_load="YES" mmcsd_load="YES" sdhci_load="YES"
DESCRIPTION¶
The sdhci
driver supports PCI devices with
class 8 and subclass 5 according to SD Host Controller Specification. Driver
supports up to six high speed 4bit MMC/SD slots per controller. Driver
attaches mmc bus to the respective slot on card insertion and detaches it on
card removing.
HARDWARE¶
The sdhci
driver supports different
specification compatible chips. The following chips have been verified to
work:
- ENE CB712
- ENE CB714
- RICOH R5C822
- RICOH R5CE823
- TI PCIXX21/XX11/XX12
SEE ALSO¶
SD Specifications, Part 2, SD Host Controller, Simplified Specification.
AUTHORS¶
Alexander Motin <mav@FreeBSD.org>
BUGS¶
Many of existing SD controller chips have some nonstandard requirements, proprietary registers and hardware bugs, requiring additional handling. ENE chips are handled to work fine, while some revisions of RICOH and TI controllers still do not see cards without some additional initialization.
August 25, 2020 | Debian |