From: Ben J. <mya...@gm...> - 2012-03-28 20:16:49
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Hello, I am writing a custom character device driver. When the open function is called in the kernel code I am looking to pull out some piece of unique information out of either the inode struct or the file struct that could then be used to identify during subsequent reads and writes. Everything that I have tried to pull out so far has been zero. Has anyone done this with success before? I am also open to the idea of setting something in the inode or file struct that will be preserved and could be read back during subsequent read and write calls. Any ideas? Thanks, Ben |
From: Harvey C. <hch...@3g...> - 2012-03-28 23:53:42
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On Mar 28, 2012, at 4:16 PM, Ben Johnson wrote: > I am writing a custom character device driver. When the open > function is called in the kernel code I am looking to pull out some > piece of unique information out of either the inode struct or the file > struct that could then be used to identify during subsequent reads and > writes. Everything that I have tried to pull out so far has been > zero. Has anyone done this with success before? The gpio event driver does this: http://wiki.gumstix.org/index.php?title=GPIO_Event_Driver |
From: AKS <aun...@gm...> - 2012-03-29 00:15:22
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"User space" or "kernel space" driver for your character device driver? On 3/28/12, Ben Johnson <mya...@gm...> wrote: > Hello, > I am writing a custom character device driver. When the open > function is called in the kernel code I am looking to pull out some > piece of unique information out of either the inode struct or the file > struct that could then be used to identify during subsequent reads and > writes. Everything that I have tried to pull out so far has been > zero. Has anyone done this with success before? > > I am also open to the idea of setting something in the inode or file > struct that will be preserved and could be read back during subsequent > read and write calls. Any ideas? > > Thanks, > Ben > > ------------------------------------------------------------------------------ > This SF email is sponsosred by: > Try Windows Azure free for 90 days Click Here > http://p.sf.net/sfu/sfd2d-msazure > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |
From: Ben J. <mya...@gm...> - 2012-03-29 12:45:26
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The gpio driver was a good example of what I was looking for. Thanks for the suggestion! On Wednesday, March 28, 2012, AKS wrote: > "User space" or "kernel space" driver for your character device driver? > > On 3/28/12, Ben Johnson <mya...@gm... <javascript:;>> wrote: > > Hello, > > I am writing a custom character device driver. When the open > > function is called in the kernel code I am looking to pull out some > > piece of unique information out of either the inode struct or the file > > struct that could then be used to identify during subsequent reads and > > writes. Everything that I have tried to pull out so far has been > > zero. Has anyone done this with success before? > > > > I am also open to the idea of setting something in the inode or file > > struct that will be preserved and could be read back during subsequent > > read and write calls. Any ideas? > > > > Thanks, > > Ben > > > > > ------------------------------------------------------------------------------ > > This SF email is sponsosred by: > > Try Windows Azure free for 90 days Click Here > > http://p.sf.net/sfu/sfd2d-msazure > > _______________________________________________ > > gumstix-users mailing list > > gum...@li... <javascript:;> > > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > > > > ------------------------------------------------------------------------------ > This SF email is sponsosred by: > Try Windows Azure free for 90 days Click Here > http://p.sf.net/sfu/sfd2d-msazure > _______________________________________________ > gumstix-users mailing list > gum...@li... <javascript:;> > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |