spi: add spi_set_speed func

This func helps mmc_spi driver set correct speed for mmc/sd, as
mmc card needs 400KHz clock for spi mode initialization.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This commit is contained in:
Thomas Chou 2010-12-24 15:16:07 +08:00 committed by Mike Frysinger
parent f02efacc51
commit fa1423e707

View File

@ -175,6 +175,14 @@ void spi_cs_activate(struct spi_slave *slave);
*/
void spi_cs_deactivate(struct spi_slave *slave);
/*-----------------------------------------------------------------------
* Set transfer speed.
* This sets a new speed to be applied for next spi_xfer().
* slave: The SPI slave
* hz: The transfer speed
*/
void spi_set_speed(struct spi_slave *slave, uint hz);
/*-----------------------------------------------------------------------
* Write 8 bits, then read 8 bits.
* slave: The SPI slave we're communicating with