rather than SDHCI_RESET_ALL; the latter turns off clocks and power, removing
any possibility of recovering from the error.
Also, double the timeout to 2 seconds. Despite what the SD spec says about
all transactions completing in 250ms or less, I have a card which sometimes
takes more than a second to complete a write.
If the hardware is not in a good state (like maybe clocks aren't running
because of a configuration glitch) its timeout clock may also not work
correctly, and the next command sent will hang that thread forever. The
thread in question is usually the one and only thread (at init time) or
a bio queue worker thread whose lockup will eventually lead to the whole
system locking up when it runs out of buffers.
No sd card command should take longer than 250ms. This new code establishes
a 1-second timeout to allow plenty of safety margin over that.
Normally it never needs to wait here at all; waiting is done at the end
of the prior command. When doing a crash dump, the normal interrupt
mechanism isn't used; instead the interrupt handler is called repeatedly
in a polling-like manner. This can subvert hardware-specific drivers
and lead to trying to start a new command while the previous command is
still busy on the bus. Since the SD spec says the longest a card can
take to execute any command is 250ms, use that as a timeout.
to check the status property in their probe routines.
Simplebus used to only instantiate its children whose status="okay"
but that was improper behavior, fixed in r261352. Now that it doesn't
check anymore and probes all its children; the children all have to
do the check because really only the children know how to properly
interpret their status property strings.
Right now all existing drivers only understand "okay" versus something-
that's-not-okay, so they all use the new ofw_bus_status_okay() helper.
The sdhci spec says that if the base or timeout clock frequency in the
capabilities register is zero, the driver must obtain the frequency "from
another source." This change defines that other source to be the low-level
hardware driver, which can pre-set the frequencies in slot.max_clk and
slot.timeout_clk before calling sdhci_init_slot().
This helps with a growing number of SoCs that have sdhci base clock
frequencies that either won't fit into the range allowed by the number of
bits available in the capabilities register, or the frequency is runtime-
configurable.
the response bits the way we do in software. While the hardware is just
doing the sensible thing rather than leaving it to the software, it's in
violation of the spec by doing so. Grrrr.
has to be recalculated every time the SD clock frequency changes.
Also, tidy up the counter calculation... it makes no sense to calculate
a value one larger than the limit, then whine that it's too large and
truncate it to the limit. If the BROKEN_TIMEOUT quirk is set, don't
calculate the counter at all, just set it to the limit value.
In order to use platorm backend hardware driver should
impement three methods:
- platform_start_transfer and platform_finish_transfer
to start and finish transfer
- platform_will_handle - check whether transaction is
suitable for backend. If not - driver will fall back
to PIO mode.
Submitted by: Daisuke Aoyama <aoyama at peach.ne.jp>
Approved by: ian@
- Replace divisor numbers with more descirptive names
- Properly calculate minimum frequency for SDHCI 3.0
- Properly calculate frequency for SDHCI 3.0 in mmcbr_set_clock
- Add min_freq method to sdhci_if.m and provide default
implementation. By re-implementing this method hardware
drivers can control frequency controller operates when
executing initialization sequence
sdchi encapsulates a generic SD Host Controller logic that relies on
actual hardware driver for register access.
sdhci_pci implements driver for PCI SDHC controllers using new SDHCI
interface
No kernel config modifications are required, but if you load sdhc
as a module you must switch to sdhci_pci instead.
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
1. Both mmc_read_ivar() and sdhci_read_ivar() use the expression
'*(int *)result = val' to assign to result which is uintptr_t *.
This does not work on big-endian 64 bit systems.
2. The media_size ivar is declared as 'off_t' which does not fit
into uintptr_t in 32bit systems, change this to long.
Submitted by: kanthms at netlogicmicro com (initial version)
sdhci supports up to 65535 blocks transfers, at91_mci - one block.
Enable multiblock operations disabled before to follow at91_mci driver
limitations.
Reviewed by: imp@
Driver supports PCI devices with class 8 and subclass 5 according to
SD Host Controller Specification.
Update NOTES, enable module and static build.
Enable related mmc and mmcsd modules build.
Discussed on: mobile@, current@
