Hi Mark, I do custom builds with yocto, the meta data is from jumpnowtek. kernel version linux-stable_5.7 In addition to the info that RCN provided, I added the pin mux stuff to define all the gpio pins.
looked at the driver for the R/W issue, seems they do not set the R/W bit, they do set the RS bit, so maybe just need to add the same for the R/W bit. amf On Tuesday, November 3, 2020 at 1:29:28 PM UTC-6 Mark A. Yoder wrote: > Thanks to all for following up on this. > > amf: What device tree are you using? > > --Mark > > On Tuesday, November 3, 2020 at 10:26:52 AM UTC-5 amf wrote: > >> Just wanting to follow up on this. The LCD display is working, just had >> to remove the R/W parameter from the dts and tie the LCD R/W to ground. The >> driver does not seem to support reading from the display, so no harm in >> doing it this way. >> >> amf >> >> On Monday, November 2, 2020 at 6:56:25 PM UTC-6 amf wrote: >> >>> Hi Mark >>> Seen RCN's response below. I have several of the *hd44780 LCD displays >>> also, *spent the weekend trying to get it to work with the info RCN >>> provided. Seems the R/W line is always high, thus all the data signals are >>> distorted. If I pull the R/W line low, then the data signals are ok, but >>> nothing is written to the display. I know the displays are good, I wrote a >>> uart-to-parallel with an atmel chip several years ago. if you have success >>> with the Linux driver, I would like to know. >>> amf >>> >>> On Thursday, October 29, 2020 at 1:39:54 PM UTC-5 Mark A. Yoder wrote: >>> >>>> I've just recently discovered I have access to lots of 16x2 LCD >>>> displays. >>>> >>>> I see there are many examples of interfacing it to a Linux machine, but >>>> most are via user space. I'm looking for kernel space examples. *modinfo >>>> hd44780* shows a driver is there, but how do I use it. >>>> >>>> Is there a device tree for the hd44780 for a parallel interface? >>>> >>>> --Mark >>>> >>> -- 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/6149769b-4050-4ca7-a0c4-cba6b642bd23n%40googlegroups.com.
