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path: root/drivers/spi/mxs_spi.c
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2013-01-21mxs: clock: Use 'mxs' prefix for methodsOtavio Salvador
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br> Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Marek Vasut <marex@denx.de> Cc: Stefano Babic <sbabic@denx.de>
2013-01-21mxs: ssp: Pull out the SSP bus to regs conversionMarek Vasut
Create function which converts SSP bus number to SSP register pointer. This functionality is reimplemented multiple times in the code, thus make one common implementation. Moreover, make it a switch(), since the SSP ports are not mapped in such nice linear fashion on MX23, therefore having it a switch will simplify things there. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Andy Fleming <afleming@freescale.com> Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Stefano Babic <sbabic@denx.de>
2012-09-06MX28: SPI: Fix the DMA chainingMarek Vasut
It turns out that in order for the SPI DMA to properly support continuous transfers longer than 65280 bytes, there are some very important parts that were left out from the documentation. Firstly, the XFER_SIZE register is not written with the whole length of a transfer, but is written by each and every chained descriptor with the length of the descriptors data buffer. Next, unlike the demo code supplied by FSL, which only writes one PIO word per descriptor, this does not apply if the descriptors are chained, since the XFER_SIZE register must be written. Therefore, it is essential to use four PIO words, CTRL0, CMD0, CMD1, XFER_SIZE. CMD0 and CMD1 are written with zero, since they don't apply. The DMA programs the PIO words in an incrementing order, so four PIO words. Finally, unlike the demo code supplied by FSL, the SSP_CTRL0_IGNORE_CRC must not be set during the whole transfer, but it must be set only on the last descriptor in the chain. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Stefano Babic <sbabic@denx.de>
2012-09-06MX28: SPI: Fix the DMA DCache race conditionMarek Vasut
This patch fixes dcache-related problem. The problem manifested when dcache was enabled and the following command issued twice: mw 0x42000000 0 0x4000 ; sf probe ; sf read 0x42000000 0x0 0x10000 ; sha1sum 0x42000000 0x10000 The SHA1 checksum was correct during the first call. Yet with every subsequent call of the above command, it differed and was wrong. It turns out this was because of a race condition. On the first time the command was called, no cacheline contained any data from the destination memory location. The DMA transfered data into the location and the cache above the location was invalidated. Then the checksum was computed, but that meant the data were loaded into data cache. On any subsequent call, the DMA again transfered data into the same destination. Yet during the transfer, some of the DCache lines were evicted and written back into the main memory. Once the DMA transfer completed, the data cache was invalidated over the memory location as usual. But the data that were to be loaded back into the data cache by subsequent SHA1 checksuming were corrupted. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Stefano Babic <sbabic@denx.de>
2012-09-01MX28: SPI: Supercharge the SPI driverMarek Vasut
This change implements DMA chaining into SPI driver. This allows the transfers to go much faster, while also fixing SF issues. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Stefano Babic <sbabic@denx.de>
2012-09-01spi: fix mxs_spi_slave structure allocation to clear memoryMatt Sealey
Use calloc() instead of malloc() to allocate the mxs_spi_slave structure. Clearing the memory is necessary since most of the time this gets done super early in boot, but on warm reboots, and when SPI probing is done long after the init stages it could actually pick up previously used memory, and things like the chipselect polarity and other data end up being filled with trash data if not explicitly set by the board files. This solves a semi-random, almost unreproducable error whereby SPI devices act very, very strangly on boot. Signed-off-by: Matt Sealey <matt@genesi-usa.com> Acked-by: Stefano Babic <sbabic@denx.de>
2012-09-01mxs: Convert sys_proto.h prefixes to 'mxs'Otavio Salvador
The sys_proto.h functions (except the boot modes) are compatible with i.MX233 and i.MX28 so we use 'mxs' prefix for its methods. Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
2012-09-01mxs: prefix register structs with 'mxs' prefixOtavio Salvador
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
2012-09-01MX28: SPI: Add DMA transfer supportMarek Vasut
The DMA transfers happen only if the transfered data are larger than 512 bytes. Otherwise PIO is used. This is a small speed optimization. The DMA transfer doesn't work if unaligned transfer is requested due to the limitation of the DMA controller. This has to be fixed by introducing generic bounce buffer. Therefore the DMA feature is now disabled by default. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Stefano Babic <sbabic@denx.de> Cc: Wolfgang Denk <wd@denx.de>
2012-09-01MX28: SPI: Pull out the PIO transfer functionMarek Vasut
Pull out all the PIO transfer logic into separate function, so DMA can be added. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Stefano Babic <sbabic@denx.de> Cc: Wolfgang Denk <wd@denx.de>
2012-09-01MX28: SPI: Refactor spi_xfer a bitMarek Vasut
This makes it easier to adapt for addition of DMA support. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Stefano Babic <sbabic@denx.de> Cc: Wolfgang Denk <wd@denx.de>
2012-05-15spi: mxs: Allow other chip selects to workFabio Estevam
MXS SSP controller may have up to three chip selects per port: SS0, SS1 and SS2. Currently only SS0 is supported in the mxs_spi driver. Allow all the three chip select to work by selecting the desired one in bits 20 and 21 of the HW_SSP_CTRL0 register. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Acked-by: Marek Vasut <marex@denx.de>
2012-05-15spi: mxs: Introduce spi_cs_is_valid()Fabio Estevam
Introduce spi_cs_is_valid() for validating spi bus and chip select numbers. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Acked-by: Marek Vasut <marex@denx.de> Acked-by: Mike Frysinger <vapier@gentoo.org>
2012-03-27mxs_spi: Return proper timeout errorFabio Estevam
Instead of returning -1, it is preferred to return -ETIMEDOUT in case of timeouts. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Acked-by: Marek Vasut <marex@denx.de>
2012-02-12mx28: fix i.MX28 spi driverMatthias Fuchs
The generic spi flash driver (drivers/mtd/spi/spi_flash.c) uses the spi low level driver's spi_xfer() function with len=0 to deassert the SPI flash' chip select. But the i.MX28 spi driver rejects this call due to len=0. This patch implements an exception for len=0 with the SPI_XFER_END flag set. This results in an extra read with the chip select being deasserted afterwards. There seems to be no way to deassert the signal by hand. Signed-off-by: Matthias Fuchs <matthias.fuchs@esd.eu> Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
2011-11-11iMX28: Add SPI driverMarek Vasut
Signed-off-by: Marek Vasut <marek.vasut@gmail.com> Cc: Stefano Babic <sbabic@denx.de> Cc: Wolfgang Denk <wd@denx.de> Cc: Detlev Zundel <dzu@denx.de>