On 01/02/2017 12:36 AM, Pavel Machek wrote: > Hi! > >> I'm looking at original Maemo N900 2.6.28 sound driver and GPIOs which >> controls A/V jack detection. >> >> For reference source code of that driver can be found e.g. at alsa-devel >> ML [1] [2] or in my linux-n900 git tree, branch v2.6.28-nokia [3]. >> >> In that sound/soc/omap/rx51.c code is function rx51_set_eci_switches() >> which configures 2 gpios: RX51_ECI_SWITCH_1_GPIO = gpio 178 and >> RX51_ECI_SWITCH_2_GPIO = gpio 182 based on "eci mode" input parameter. >> >> But in mainline kernel code [4] [5] there is no information about gpio 178 >> (as RX51_ECI_SWITCH_1_GPIO) and gpio 182 is called as just "eci-switch". >> More interesting part is that "eci-switch" gpio is not used in whole >> mainline code. It is just referenced in Nokia N900 DTS [4]. Looks like >> sound driver in mainline kernel is incomplete. >> >> Jarkko, you are listed as original author of that driver. Do you (or >> anybody else) remember what that rx51_set_eci_switches() function is >> doing? And what gpio 178 controls? I was even not able to find gpio 178 >> in RX-51 Schematics [6]. >> >> And do you know something about Nokia ECI headsets supports for Nokia >> N900. Looks like there is already some kernel code but support for ECI >> bus or multibuttons headset is missing. > > What does "ECI" mean? ECI = Enhancement Control Interface apart from buttons (play/pause/skip forward/reverse, etc) the accessories can contain memory to store parameters, like audio tuning data, etc. > > I'd like to get detection of headset button presses to work in recent > kernels, but could not figure it out :-(. > > Are there multi-button headsets compatible with N900? Not sure if n900 is capable of handling ECI communication, n9 was. In n9 the PMIC/Audio chip had an ECI core integrated afaik > Best regards, > Pavel > > -- Péter -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
