Reported by Nikolaus Schaller, Apr 10, 2014
* UART2 problem * gpio-w2sg0004.c needs correct way to dynamically modify pinmux (replacement for omap_mux_set_gpio) * something wrong in the DT plumbing for the driver * rfkill has no visible effect
Comment 1 by Nikolaus Schaller, Jun 2, 2014
rfkill is now working and enables/disables the LNA power. This could be verified by monitoring the /sys/class/regulator/regulator.*/state for the "vsim" regulator. One thing should be improved: the LNA should stay powered off after booting to save energy. I.e. GPS should start up in the blocked state.
Comment 2 by Nikolaus Schaller, Aug 18, 2014
here is a description how drivers should choose between default and other pinmux states (through pinctrl_lookup_state and pinctrl_select_state): https://www.kernel.org/doc/Documentation/pinctrl.txt Focus on the sections "Pin control requests from drivers" "Runtime pinmuxing"
Comment 3 by Nikolaus Schaller, Sep 6, 2014
Fixed in 3.17-rc3! Issues were multiple: 1. pinmux states have been defined as suggested 2. the omap-serial.c DTR extension did lack code to set the DTR_present flag in the DT based platform data 3. some minor tweaks added
Comment 4 by Nikolaus Schaller, Sep 6, 2014
Comment 5 by Nikolaus Schaller, Sep 6, 2014
Comment 6 by Nikolaus Schaller, Sep 6, 2014
Comment 7 by Nikolaus Schaller, Oct 22, 2014
discussion on LKML started. Some minor feedbacks and one major issue: it appears not to be acceptable to have this "virtual GPIO" type of interface. People want to see real hardware only in the DT.
Comment 8 by Marek Belisko, Feb 23, 2015
NeilBrown started pushing slave tty devices which maintainer seems to like. More info at: http://thread.gmane.org/gmane.linux.kernel/1849147
Comment 9 by Nikolaus Schaller, Dec 17, 2016
As of today, despite multiple attempts by different groups, we still have no tty-slaves in the kernel. Of course we have our private solution which is tested, maintained by us and works. But it is completely sitting on top of mainline Linux.
Comment 10 by Nikolaus Schaller, Feb 16, 2019
Finally we have a serdev based solution in linux-next. It is only lacking the rfkill control.
Comment 11 by Nikolaus Schaller, Feb 16, 2019
Comment 12 by Nikolaus Schaller, Jul 8, 2019
Summary: GTA04 GPS: rfkill missing