And following is a link to the thread showing where we're at regarding connecting the BB-X15 to the FT4232 Mini Module, development board:
http://beagleboard.org/discuss?place=msg%2Fbeagleboard%2FLjrZqmp8dGA%2FciOgBxRBCgAJ On Thursday, August 2, 2018 at 9:52:08 AM UTC-5, Jeff Andich wrote: > > Thanks Robert!! > > Would really like to test the 485 mode in the 8250 driver, but before > that, we're going to try to get 485 mode enabled on the FTDI FT4232 > USB<->serial hub. We've ordered some FT4232 Mini Module evaluation boards > for FT4232 (FT4232H chip + EEPROM + breakout pins + mini USB port). > > The biggest what if at the moment is how to write to the onboard EEPROM > from Linux. The FT4232 data sheet indicates that an external EEPROM needs > to be attached to the FT4232H, and the RI/TXDEN flag in the EEPROM needs to > be re-configured from the default state to enable 485 mode for each of the > 4 serial channels. Thus far, > https://www.acmesystems.it/CM3-HOME_ft4232_setup > <https://www.google.com/url?q=https%3A%2F%2Fwww.acmesystems.it%2FCM3-HOME_ft4232_setup&sa=D&sntz=1&usg=AFQjCNFq8W9aFeQQRvaCyp6UYr4FGyiu-g> > looks > promising, as the EEPROM tools appear to be talking to our EEPROM-less > FT4232H chip on our custom board. . > > Plan to post up on our findings/stumbling blocks here. If we can get this > working, then this MAY be of interest to those looking for a quick RS 485 > solution. > > Regards, > > Jeff > > > On Thursday, August 2, 2018 at 8:37:26 AM UTC-5, RobertCNelson wrote: >> >> On Thu, Aug 2, 2018 at 8:22 AM Jeff Andich <[email protected]> wrote: >> > >> > Hi, >> > >> > What's the best way to find out how long a legacy driver like the >> omap-serial driver will be supported in the kernel going forward? >> >> It's not going anywhere till they are feature matching.. >> >> > >> > We've swapped out the 8250 driver for the OMAP serial driver via the >> .config file, since the omap serial driver implements a 485 mode which, >> thus far, appears to be functioning correctly for our application. On the >> next spin of our board, we plan to realize more 485 channels using the >> omap-serial driver and GPIO lines. >> > >> > We're currently "baselined" on kernel 4.4.110, but if we need to >> upgrade to a newer kernel version at some point, this could be an issue if >> the OMAP-serial driver is obsoleted in a later kernel. >> > >> > As of yet, we haven't tested the RS485 mode which has been implemented >> in the 8250 serial driver in kernel 4.6 and later, but if there are known >> plans for dropping support for the omap-serial driver, then we will >> definitely test the 8250/RS485 implementation. >> > >> > Thus far have looked at the following, and didn't SEE any plans for >> obsolescence: >> > >> > >> https://github.com/torvalds/linux/commits/master/drivers/tty/serial/omap-serial.c >> >> > >> > Also, comments like the following lead me to believe that the >> omap-serial driver will be around as long as the omap platform >> > is still supported. It SOUNDS almost like the 8250 driver is generic >> for other platforms (e.g. other than OMAP) which >> > don't support DMA. >> > >> > >> > * Note: This driver is made separate from 8250 driver as we cannot >> > * over load 8250 driver with omap platform specific configuration for >> > * features like DMA, it makes easier to implement features like DMA and >> > * hardware flow control and software flow control configuration with >> > * this driver as required for the omap-platform >> >> Yeah, that "was" pretty much the state of the 8250 driver circa 2.6.32 >> >> 485 mode is really the only thing the omap driver does better at this >> point in today's kernel.. >> >> Regards, >> >> -- >> Robert Nelson >> https://rcn-ee.com/ >> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/522b7675-44ac-4e93-8257-7a303400da58%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
