2008-03-25 23:20:52 Operate SPI port full duplex
DAVID ZHOU (CHINA)
Message: 53022
In my driver I want to operate SPI port full duplex, How should I do ?
That is mean : from the first bit of the data transfer ,the received bit is valid . Atfer I send out 3 bytes, I will have received 3 bytes data.
Second question:
I have read the spi_bf5xx.c source code,
when read, the MOSI line will send out 0xFFFF, but 0xFFFF will be a valid command for my SPI slave chip. If I want to send out 0x0000 on MOSI line. How should I do ?
Thanks.
My uclinux version and toolchain are 2008 new release version.
I have read the spi documents, but It do not tell me how to do.
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2008-03-26 00:36:13 Re: Operate SPI port full duplex
Mike Frysinger (UNITED STATES)
Message: 53027 did you read the wiki as well as the external resources ? full duplex transfers are covered
http://docs.blackfin.uclinux.org/doku.php?id=spi
linux-2.6.x/include/linux/spi/spi.h
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2008-03-26 02:15:01 Re: Operate SPI port full duplex
DAVID ZHOU (CHINA)
Message: 53031
Thanks! Mike.
I have read that, but only find spi_write_then_read(), It is a half-duplex, not full-duplex.
Also there are duplex functions, such as :
static void u8_duplex(struct driver_data *drv_data)
But I do not know how to call it.
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2008-03-26 10:06:14 Re: Operate SPI port full duplex
Mike Frysinger (UNITED STATES)
Message: 53056 read the header file i referred to ... you could also read existing spi drivers