Hi Rob, > Am 23.05.2017 um 15:10 schrieb Rob Herring <robh+dt@xxxxxxxxxx>: > > +Marcel Good! > > On Tue, May 23, 2017 at 7:48 AM, H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote: >> Hi Rob, >> >>> Am 23.05.2017 um 14:28 schrieb Rob Herring <robh+dt@xxxxxxxxxx>: >>> >>> On Tue, May 23, 2017 at 12:43 AM, H. Nikolaus Schaller >>> <hns@xxxxxxxxxxxxx> wrote: >>>> Hi Rob, >>>> >>>>> Am 23.05.2017 um 04:26 schrieb Rob Herring <robh+dt@xxxxxxxxxx>: >>>>> >>>>> On Sun, May 21, 2017 at 5:44 AM, H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote: >>>>>> Since our proposed API was not acceptable and the new serdev API has arrived in 4.11 kernels, >>>>>> we finally took the challenge to update the w2sg and w2cbw drivers to use the serdev API. >>>>>> >>>>>> The approach is to write a "man in the middle" driver which is on one side a serdev client >>>>>> which directly controls the UART where the device is connected to and on the other side >>>>>> presents a new tty port so that user-space software can talk to the chips as if they would >>>>>> directly talk to the UART of the SoC (e.g. ttyO1). This is similar to connecting to a remote >>>>>> serial device e.g. through USB (ttyACM) or Bluetooth UART profiles. >>>>>> >>>>>> For example gpsd or hciattach expect a /dev/tty they can control (flow control, baud rate >>>>>> etc.). >>>>> >>>>> I understand from the prior discussion why you want to pass the data >>>>> thru for gps, but why do you need to do that for BT? >>>> >>>> Because we otherwise can't turn on power when /dev/ttyBT0 is opened and turn off when it >>>> is closed. I.e. it should not be powered unless someone does a hciattach /dev/ttyBT0. And it >>>> should be turned off by a killall hciattach. >>> >>> Still, you can do power control within BT HCI drivers. >> >> We do not use any driver for bluetooth. We just start hciattach on demand. >> And afaik there is no plugin mechanism for adding power control to hciattach. > > You don't need hciattach. All userspace has to do for kernel BT > drivers is "hciconfig hci0 up|down". Hm. Well: root@letux:~# hciconfig hci0 up Can't get device info: No such device root@letux:~# I wonder how I can tell hciconfig about the UART port if not by running hciattach /dev/ttyBT0? > >> Or do you have a link to what you think about? > > Look at the nokia BT or TI (HCI_LL) BT drivers. Those both have f/w > downloading and some GPIO controls. Given that this module is based on > Marvell chipset, I'd expect you need to add serdev support to > hci_mrvl.c. The w2cb003 has a Marvell WiFi (libertas) but a CSR Bluetooth side. It has built-in firmware and already talks serial HCI over simple UART right after power-on. This is why our serdev driver has no firmware download. > >>> You wouldn't be >>> limited to just open/close, but can handle suspend/resume as well. >> >> Well, it does not look as if we need more than open/close since suspend/resume >> is already handled by the regulator driver. We just need to keep it powered off >> if there is no user-space client. > > Okay. > > Rob BR, Nikolaus -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
