On Mon, Oct 14, 2013 at 03:05:58AM +0800, YouShenghui wrote: Please fix your mailer to word wrap within paragraphs, your messages are very hard to read. > Ok, I have one question when reading drivers/spi/spi-s3c64xx.c > In s3c64xx_spi_setup, cs->line(S3C64XX_GPC(3)) is set to GPIOF_OUT_INIT_HIGH, that means an general output pin. > But the other three(clk, mosi, miso) was set to 2 by s3c64xx_spi0_cfg_gpio. This is just what is needed by SPI. > My question is why wasn't cs->line also set to 2 to use SPI CS0? In common with many drivers this driver controls the chp select as a GPIO. Generally the hardware is less flexible than Linux can be if it implements automatic chip select handling at all. > When I want to use spi as slave side, should I set S3C64XX_GPC(3)'s cfg of to 0(input) or 2? I don't think the controller has any slave support natively so you'd probably need to put it into GPIO mode.
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