From mboxrd@z Thu Jan 1 00:00:00 1970 From: eric@anholt.net (Eric Anholt) Date: Thu, 09 Jun 2016 10:22:27 -0700 Subject: [PATCH 27/32] gpio: Add support for the FXL6408 GPIO expander. In-Reply-To: References: <1464817421-8519-1-git-send-email-kraxel@redhat.com> <1464817421-8519-28-git-send-email-kraxel@redhat.com> Message-ID: <878tyexooc.fsf@eliezer.anholt.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Linus Walleij writes: > On Wed, Jun 1, 2016 at 11:43 PM, Gerd Hoffmann wrote: > >> +#define FXL6408_OUTPUT 0x05 >> +/* Bits here make the output High-Z, instead of the OUTPUT value. */ >> +#define FXL6408_OUTPUT_HIGH_Z 0x07 > (...) >> + /* Disable High-Z of outputs, so that our OUTPUT updates >> + * actually take effect. >> + */ >> + i2c_smbus_write_byte_data(client, FXL6408_OUTPUT_HIGH_Z, 0); > > High-Z is probably the same as open drain right? And if not open drain, > it is push-pull. > > So you want to implement .set_single_ended() for configuring the lines in > "high-z", i.e. open drain output mode. I'll keep this in mind for whenever I end up writing my next GPIO driver, but this one is dead for now (not actually usable because of the closed firmware). -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 818 bytes Desc: not available URL: