b55f627fee
Add two new spi_device.mode bits to accomodate more protocol options, and pass them through to usermode drivers: * SPI_NO_CS ... a second 3-wire variant, where the chipselect line is removed instead of a data line; transfers are still full duplex. This obviously has STRONG protocol implications since the chipselect transitions can't be used to synchronize state transitions with the SPI master. * SPI_READY ... defines open drain signal that's pulled low to pause the clock. This defines a 5-wire variant (normal 4-wire SPI plus READY) and two 4-wire variants (READY plus each of the 3-wire flavors). Such hardware flow control can be a big win. There are ADC converters and flash chips that expose READY signals, but not many host controllers support it today. The spi_bitbang code should be changed to use SPI_NO_CS instead of its current nonportable hack. That's a mode most hardware can easily support (unlike SPI_READY). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: "Paulraj, Sandeep" <s-paulraj@ti.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| .. | ||
| ad7877.h | ||
| ad7879.h | ||
| ads7846.h | ||
| at73c213.h | ||
| corgi_lcd.h | ||
| ds1305.h | ||
| eeprom.h | ||
| flash.h | ||
| Kbuild | ||
| libertas_spi.h | ||
| max7301.h | ||
| mcp23s08.h | ||
| mmc_spi.h | ||
| orion_spi.h | ||
| spi_bitbang.h | ||
| spi_gpio.h | ||
| spi.h | ||
| spidev.h | ||
| tdo24m.h | ||
| tle62x0.h | ||
| wl12xx.h | ||