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
SEE ALSO¶
mmc(4),
mmcsd(4)
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.