- In SPI mode, the card will respond to the initial SDIO reset (done
using CMD52) with “invalid command” error. Handle this correctly.
- sdmmc_card_init had a hack where GO_IDLE_STATE (CMD0) command was
sent twice. Add explanation why this is done, and don’t expect
correct response from the card on first CMD0.
- improve logs printed at debug level by adding CMD index
- Split SDMMC page into pages about SDMMC/SDSPI hosts and a page about
the protocol layer.
- Use autogenerated API reference instead of manually generated one.
- Add information about SDIO APIs.
- Add SDIO support at protocol layer (probing, data transfer, interrupts)
- Add SDIO interrupts support in SDMMC host
- Add test (communicate with ESP32 in SDIO download mode)
Existing code assumed that response timeout is not followed by CMD_DONE,
which was not true, in fact. Host datasheet states that CMD_DONE is sent
after an RTO.
All the commands which do not have a response must have their flags set
accordingly. Therefore the host will not send RTO interrupt if response
is not expected. It is a bug in the code logic if it happens otherwise.
SDMMC host suffers from an issue that it outputs data near the rising
edge of the card clock, which is the edge used by the card to sample
data. If sampling time constraint is not satisfied, card may read data
after the transition.
The phases of output/input data can, in fact, be adjusted. However this
adjustment happens in the clock generation block outside of the host.
So the maximum phase change which can be created this way is equal to
half of the host clock period. So if the host clock is set to the lowest
possible frequency (for the given card frequency), then the phase offset
(and hence the hold time) will be the highest. This change modifies the
logic used to determine clock dividers accordingly.
sdmmc host: set correct dout phase and print correct frequency
SET_BUS_WIDTH is not a data transfer command. Extensive search in the
host datasheet and SD card spec did not reveal the origin of this hack
or 'feature'. Further testing showed that removing this does not lead to
regressions.
Fixes exceptions LoadProhibited, when rmt tries read variable p_rmt on RX END which can be 0.
It happens after esp_reset() (OTA) and the rmt is not probably stopped by it.
In other words the routine rmt_driver_isr_default was called before second rx channel was registered.
scenario:
register tx channel
register rx channel
reboot
register tx channel
-> exception (because rx channel is accessed)
Merges https://github.com/espressif/esp-idf/pull/1671
