Thu, May 25, 2023 at 12:03:23AM -0400, Hugo Villeneuve kirjoitti: > From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> > > If the shared GPIO pins on a dual port/channel variant like the > SC16IS752 are configured as GPIOs for port A, and modem control lines > on port A, we need to translate the Linux GPIO offset to an offset > that is compatible with the I/O registers of the SC16IS7XX (IOState, > IODir and IOIntEna). > > Add a new variable to store that offset and set it when we detect that > special case. ... > +/* > + * We may need to translate the Linux GPIO offset to a SC16IS7XX offset. > + * This is needed only for the case where a dual port variant is configured to > + * have only port B as modem status lines. > + * > + * Example for SC16IS752/762 with upper bank (port A) set as GPIOs, and > + * lower bank (port B) set as modem status lines (special case described above): > + * > + * Pin GPIO pin Linux GPIO SC16IS7XX > + * name function offset offset > + * -------------------------------------------------- > + * GPIO7/RIA GPIO7 3 7 > + * GPIO6/CDA GPIO6 2 6 > + * GPIO5/DTRA GPIO5 1 5 > + * GPIO4/DSRA GPIO4 0 4 > + * GPIO3/RIB RIB N/A N/A > + * GPIO2/CDB CDB N/A N/A > + * GPIO1/DTRB DTRB N/A N/A > + * GPIO0/DSRB DSRB N/A N/A > + * > + * Example for SC16IS750/760 with upper bank (7..4) set as modem status lines, Single space is enough. > + * and lower bank (3..0) as GPIOs: > + * > + * Pin GPIO pin Linux GPIO SC16IS7XX > + * name function offset offset > + * -------------------------------------------------- > + * GPIO7/RI RI N/A N/A > + * GPIO6/CD CD N/A N/A > + * GPIO5/DTR DTR N/A N/A > + * GPIO4/DSR DSR N/A N/A > + * GPIO3 GPIO3 3 3 > + * GPIO2 GPIO2 2 2 > + * GPIO1 GPIO1 1 1 > + * GPIO0 GPIO0 0 0 > + */ Wondering if you can always register 8 pins and use valid mask to define which one are in use? -- With Best Regards, Andy Shevchenko
