- Switch to 25MHz clock
- Switch to 4bit transfers mode (the default is 1bit)
Reading and writing SD cards do not seem to work anymore with these
changes. I get invalid data on read, and on write, an interrupt is never
called in some cases.
The main differences:
- The initialization sequence requires an additional command (this was
already done)
- The layout of the CSD register and the way to compute the device
geometry from it changes
- The read and write commands parameter is a sector number instead of a
byte position
Change-Id: Ie729e333c9748f36b37acd70c970adfd425cf0b6
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3512
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
The SDHCI spec also offers an "advanced DMA" mode where we can use
scatter-gather lists. It would allow to remove several of the DMA
restrictions, but hardware support for it is optional, so we need this
version anyway.
The geometry is retrieved on demand in the first read or write or in a
call to the get geometry or get device size ioctl. It is not possible to
retrieve it from the device initialization because that is called as
part of the mmc_bus scanning, which needs a specific sequence of
commands and keeps the bus locked to prevent drivers to insert their own
commands in the middle of that sequence.
TODO:
- Move the DMA restrictions definition to sdhci_pci and forward it up to
mmc_disk (which is the one creating the IOScheduler)
- Decide if we want to keep non-DMA support (probably should, but it
makes things more complex, because it uses virtual addresses)
Change-Id: Ib1dd14eacf62052d747bfb3ef7820bc5a34d3030
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3471
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
First implementation of reading sectors from an SD card.
This is not the best performance for many reasons:
- No DMA
- Reads only one sector at a time
- Cannot read more than 512 bytes per syscall
Also there are major limitations:
- Cannot read less than 512 bytes. The hardware of course works in full
sectors. The mmc_disk driver should go through the io scheduler to
make sure requests have a reasonable size and offset, and nothing
tries to read just a few bytes in the middle of a sector.
- SD cards only (no SDHC, no MMC)
Architecture problems:
I think too much of the implementation is done in sdhci_pci and should
be moved to the upper layers. However it is difficult to say without
having implemented DMA (which indeed will be at the low level of the
sdhci controller). It doesn't help that the order of operations is a
bit different depending on wether there is DMA or not. In DMA mode you
first prepare the buffer, then run the command. In non-DMA mode you
first send the command, then read the data into the buffer. We need an
API at the mmc_bus level that doesn't care about that low-level detail.
There are other things that the MMC bus should be doing however, such
as switching to different clock speeds depending on which card is
activated and how fast it can go.
At least the following should be done:
- The read method for mmc_bus and sdhci_pci should use a scatter-gather
structure as a parameter instead of a single buffer
- See if can be integrated into ExecuteCommand at sdhci level (it's
essentially a command with an additional data phase)
Change-Id: I688b6c694561074535c9c0c2545f06dc04b06e7d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3466
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
No read and write support for now. But we implement getting SD card
capacity. SDHC is not supported yet (it uses a different layout for the
CSD register which will be rejected by this version of the code)
Change-Id: Ife844a62f3846c0a780259e9a3a08195e2fd965e
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1068
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
For now it just forwards the command to the SDHCI controller.
The bus will gain more features and functions as work advances (tracking
which card is active, arbitration of DMA transfers, etc).
Change-Id: I094eb84f27e7789387a3f8fb65fba1e5fcfa3e8a
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3094
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
sdhci:
- Add semaphore for interrupt management
- Add basic operations (setting clock, executing a command)
- Add early initialization (clocks and power up)
- Wrap the bus in a C++ class to ease usage
- Expose API to MMC bus manager
- TODO: manage card insertion and removal interrupts
- TODO: use MSI when available
mmc_bus:
- Implements SD card management independant of the way we access the bus
(later on different drivers can provide the same API as SDHCI)
- Worker thread to do the initialization
- Implement card initialization process up until getting an RCA from the
card. This is the generic part to assign an ID to the card, after this
point commands can be targetted at the specific card so it can be
handed over to the mmc_disk driver.
- TODO: initialization for non-SDHC cards which do not reply to CMD8.
Change-Id: I71950ca3ce206378a68fa7f97c19f638183d6cdd
Reviewed-on: https://review.haiku-os.org/c/1032
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
