On Sat, Jan 11, 2014 at 04:37:32PM -0800, Insop Song wrote:
> On Sat, Jan 11, 2014 at 4:10 PM, Greg KH <gre...@linuxfoundation.org> wrote:
> > On Sat, Jan 11, 2014 at 03:56:48PM -0800, Insop Song wrote:
> >> On Sat, Jan 11, 2014 at 1:05 PM, Greg KH <gre...@linuxfoundation.org>
> >> wrote:
> >> > On Sat, Jan 11, 2014 at 12:51:28PM -0800, Greg KH wrote:
> >> >> On Thu, Jan 09, 2014 at 11:48:04AM -0800, Insop Song wrote:
> >> >> > This driver downloads Xilinx FPGA firmware using gpio pins.
> >> >> > It loads Xilinx FPGA bitstream format firmware image and
> >> >> > program the Xilinx FPGA using SelectMAP (parallel) mode.
> >> >> >
> >> >> > Signed-off-by: Insop Song <insop.s...@gainspeed.com>
> >> >>
> >> >> This patch breaks the build on my machine, please be more careful:
> >> >>
> >> >> drivers/staging/gs_fpgaboot/gs_fpgaboot.c:30:28: fatal error:
> >> >> include/asm/io.h: No such file or directory
> >> >> #include <include/asm/io.h>
> >> >>
> >> >> Please fix this up, test it, and resend.
> >> >
> >> > Also, while you are fixing things up, please just remove the character
> >> > device node from the driver, you aren't doing anything with it, so it's
> >> > not needed.
> >> >
> >>
> >> Thank you for the suggestion, makes a lot of sense and code cleaner.
> >>
> >> Could you take a quick look?
> >> If it is good, will send out a new patch, v5, shortly.
> >>
> >> Main change is
> >>
> >> +/* fake device for request_firmware */
> >> +static struct platform_device *firmware_pdev;
> >>
> >> + firmware_pdev = platform_device_register_simple("fpgaboot", -1,
> >> + NULL, 0);
> >
> > Why do you need a platform device? Don't you have something on the
> > hardware that describes the fact that this device is in the system, or
> > not? Like a PCI id? DMI id? Device Tree entry?
> >
> > You must have something that you can trigger off of.
> >
>
> This driver is only to download fpga firmware, not intended to keep
> managing the fpga device after the downloading. The device we use is
> not part of the device tree or PCI.
But how does the system know to load it or not, automatically?
> It downloads the image and after that no need to be existing.
Then why not have the module remove itself?
> Here is how we use
>
> $ insmod gs_fpga.ko file="xlinx_fpga_top_bitstream.bit"
> $ rmmod gs_fpga
Linux modules should be able to be autoloaded based on hardware present
in the system, it's been that way for over a decade now.
> I still needed "device" to use request_firmware() even though I don't
> use it. I've looked at other drivers which uses request_firmware()
> after your suggestion of removing char device node, and I've found
> platform_device can be a simple one to use.
Please base your device on a real one in the system, like your FPGA
device, surely there is some way it can be detected to be present or
not?
thanks,
greg k-h
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