Messages in this thread |  | | From | Rick Altherr <> | Date | Fri, 25 Aug 2017 09:53:40 -0700 | Subject | Re: [patch v6 0/3] JTAG driver introduction |
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On Fri, Aug 25, 2017 at 1:50 AM, Stuart Longland <stuartl@longlandclan.id.au> wrote: > [Note: dropping vadimp@maellanox.com as SMTP server complained about the > DNS server returning NXDOMAIN. Apologies.] > On 25/08/17 18:32, Linus Walleij wrote: >> Gnah! >> Whoever writes a slot-in replacement making the character device >> take precendence wins lots of karma. > > What would such a replacement look like though?
See Linus's comments about using the existing kernel GPIO chardev interface. It already supports requesting multiple GPIO line state changes in a single request.
> > Some sort of system whereby you can read/write single-line commands as > if talking to a GPIO expander over a UART? > > Would you access the GPIOs one by one, or would you perhaps map them > into a bitmap (maybe arbitrarily, up to 64-bits wide) and perform masked > operations on the bitmap? > > I'm no fan of the sysfs GPIO interface, but it beats poking around at > registers behind the kernel's back. > -- > Stuart Longland (aka Redhatter, VK4MSL) > > I haven't lost my mind... > ...it's backed up on a tape somewhere. >
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