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Diffstat (limited to 'Documentation/blackfin/bfin-spi-notes.txt')
| -rw-r--r-- | Documentation/blackfin/bfin-spi-notes.txt | 16 |
1 files changed, 0 insertions, 16 deletions
diff --git a/Documentation/blackfin/bfin-spi-notes.txt b/Documentation/blackfin/bfin-spi-notes.txt deleted file mode 100644 index eae6eaf2a09d..000000000000 --- a/Documentation/blackfin/bfin-spi-notes.txt +++ /dev/null @@ -1,16 +0,0 @@ -SPI Chip Select behavior: - -With the Blackfin on-chip SPI peripheral, there is some logic tied to the CPHA -bit whether the Slave Select Line is controlled by hardware (CPHA=0) or -controlled by software (CPHA=1). However, the Linux SPI bus driver assumes that -the Slave Select is always under software control and being asserted during -the entire SPI transfer. - And not just bits_per_word duration. - -In most cases you can utilize SPI MODE_3 instead of MODE_0 to work-around this -behavior. If your SPI slave device in question requires SPI MODE_0 or MODE_2 -timing, you can utilize the GPIO controlled SPI Slave Select option instead. -In this case, you should use GPIO based CS for all of your slaves and not just -the ones using mode 0 or 2 in order to guarantee correct CS toggling behavior. - -You can even use the same pin whose peripheral role is a SSEL, -but use it as a GPIO instead. |