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path: root/include/linux/gnss.h
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2019-02-15gnss: add mtk receiver type supportLoys Ollivier1-0/+1
Add an MTK (Mediatek) type to the "GNSS_TYPE" attribute. Note that MTK receivers support a subset of NMEA 0183 with vendor extensions. Signed-off-by: Loys Ollivier <lollivier@baylibre.com> Signed-off-by: Johan Hovold <johan@kernel.org>
2018-06-28gnss: add receiver type supportJohan Hovold1-0/+9
Add a "type" device attribute and a "GNSS_TYPE" uevent variable which can be used to determine the type of a GNSS receiver. The currently identified types reflect the protocol(s) supported by a receiver: "NMEA" NMEA 0183 "SiRF" SiRF Binary "UBX" UBX Note that both SiRF and UBX type receivers typically support a subset of NMEA 0183 with vendor extensions (e.g. to allow switching to the vendor protocol). Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-28gnss: add GNSS receiver subsystemJohan Hovold1-0/+66
Add a new subsystem for GNSS (e.g. GPS) receivers. While GNSS receivers are typically accessed using a UART interface they often also support other I/O interfaces such as I2C, SPI and USB, while yet other devices use iomem or even some form of remote-processor messaging (rpmsg). The new GNSS subsystem abstracts the underlying interface and provides a new "gnss" class type, which exposes a character-device interface (e.g. /dev/gnss0) to user space. This allows GNSS receivers to have a representation in the Linux device model, something which is important not least for power management purposes. Note that the character-device interface provides raw access to whatever protocol the receiver is (currently) using, such as NMEA 0183, UBX or SiRF Binary. These protocols are expected to be continued to be handled by user space for the time being, even if some hybrid solutions are also conceivable (e.g. to have kernel drivers issue management commands). This will still allow for better platform integration by allowing GNSS devices and their resources (e.g. regulators and enable-gpios) to be described by firmware and managed by kernel drivers rather than platform-specific scripts and services. While the current interface is kept minimal, it could be extended using IOCTLs, sysfs or uevents as needs and proper abstraction levels are identified and determined (e.g. for device and feature identification). Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>