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31a2c906d7
- Move DMA tag and map creature to at91_spi_activate() where the other resource allocation also lives. [1] - Flesh out at91_spi_deactivate(). [1] - Work around the "Software Reset must be Written Twice" erratum. - For now, run the bus at the slowest speed possible in order to work around data corruption on transit even seen with 9 MHz on ETHERNUT5 (15 MHz maximum) and AT45DB321D (20 MHz maximum). This also serves as a poor man's work-around for the "NPCSx rises if no data data is to be transmitted" erratum of RM9200. Being able to use the appropriate bus speed would require: 1) Adding a proper work-around for the RM9200 bug consisting of taking the chip select control away from the SPI peripheral and managing it directly as a GPIO line. 2) Taking the maximum frequencies supported by the actual board and the slave devices into account and basing the whole thing on the master clock instead of hardcoding a divisor as previously done. 3) Fixing the above mentioned data corruption. - KASSERT that TX/RX command and data sizes match on transfers. - Introduce a mutex ensuring that only one child device is running a SPI transfer at a time. [1] - Add preliminary, #ifdef'ed out support for setting the chip select. [1] - Use the RX instead of the TX commando size when setting up the RX side of a transfer. - For controllers having SPI_SR_TXEMPTY, i.e. !RM9200, also wait for the completion of the TX part of transfers before stopping the whole thing again. - Use DEVMETHOD_END. [1] - Use NULL instead of 0 for pointers. [1, partially] Additional testing by: Ian Lepore Submitted by: Ian Lepore [1] MFC after: 1 week |
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sa11x0 | ||
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