Re: [PATCH 2/2] HID: mcp2221: configure GP pins for GPIO function

Thanks Linus.

Hi Tobias, few observations on code:
1. Copy-paste error; please change set to get in comments for struct
mcp_get_sram_settings.
2. If mcp_configure_gp() fails, we have invalid copy of
mcp->gp_runtime_settings (new value is not set actually but we have
updated this array with new value)..

Regards,
Rishi

On Fri, Sep 17, 2021 at 4:44 AM Linus Walleij [off-list ref] wrote:

On Wed, Aug 18, 2021 at 5:28 PM Tobias Junghans
[off-list ref] wrote:

quoted

Per default the GP pins of an MCP2221 are designated to a certain
dedicated or alternate function. While it's possible to change these
defaults by manually updating the internal flash, it's much more
convenient and safe to configure the GP pins as GPIOs automatically
at runtime whenever the corresponding GPIO line is requested. The
previous setting is restored as soon as the GPIO line is freed again.

Signed-off-by: Tobias Junghans <redacted>

My sympathies are usually on the side of users trying to make
use of their hardware and they should be able to.

For other wrong configured GPIO expanders such as FTDI
a publicly available firmware reflash tool exists, and if that does
not exist for this hardware, I think this approach is legitimate.

Acked-by: Linus Walleij <redacted>

Yours,
Linus Walleij