Re: Change MODE, CS, BUS, and SPEED using SPI-DEV driver?

["Charles Martel" <SingerIsland-KK0ffGbhmjU@public.gmane.org>]

----- Original Message -----
From: David Brownell
Sent: 10/01/10 08:02 PM
To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Charles Martel
Subject: Re: Change MODE, CS, BUS, and SPEED using SPI-DEV driver?

--- On Fri, 10/1/10, Charles Martel <SingerIsland-KK0ffGbhmjU@public.gmane.org> wrote: >> >> The question I have is how do I modify these settings? > Evidently you haven't yet looked at the > documentation. Try that. There's a sample > program which will be informative.

Thank you for your reply.

1) I have read numerous documents but don't see where they
explain what I need considering that only the following SPI driver
files are built:
 built-in.o, hspi-s3c64xx.o, spi.o, and spi-dev.o.

I had built a kernel for the s3c6410 using linux-2.6.24.
I noticed that there are drivers for the s3c24xx but only the
"S3C6410 High Speed SPI Driver" is specific to the s3c6410.
I do not believe that the the s3c24xx series drivers are
compatible with the s3c6410. Am I wrong?
The problem I am having would go away if I could use the
s3c24xx drivers since they result in the spidev.c file being
built.

2) The following all return 0 (debug message: "Invalid ioctl option"):
 ret = ioctl(fd, SPI_IOC_WR_MODE, &spiMode);
 ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bitsPerWord);
 ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &spiSpeed);
 These ioctl functions are supported by the spidev_ioctl function in spidev.c.
 However, as mentioned above, the "S3C6410 High Speed SPI Driver"
 does not build spidev.c.

 The same result happens when I use the following ioctl call:
 ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
 where tr structure (spi_ioc_transfer) contains the following:
 tr.tx_buf = txBuf;
 tr.rx_buf = rxBuf;
 tr.delay_usecs = delay;
 tr.speed_hz = speed;
 tr.bits_per_word = 8;
 tr.pad = 0;
 tr.cs_change = 0;

 This is what I expect since spi-dev.c does not handle these ioctl requests.
 The spidev_ioctl function in spi-dev.c only handles the following:
 SET_SPI_FLAGS, SET_SPI_RETRIES, and SET_SPI_TIMEOUT.

3) The following always succeeds:
 ret = write(fd, txBuf, xLen);
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