Hi Dmitry, >>> This is an RFC of the proposed power sequencer subsystem. This is a >>> generification of the MMC pwrseq code. The subsystem tries to abstract >>> the idea of complex power-up/power-down/reset of the devices. >>> >>> The primary set of devices that promted me to create this patchset is >>> the Qualcomm BT+WiFi family of chips. They reside on serial+platform >>> interfaces (older generations) or on serial+PCIe (newer generations). >>> They require a set of external voltage regulators to be powered on and >>> (some of them) have separate WiFi and Bluetooth enable GPIOs. >>> >>> This patchset being an RFC tries to demonstrate the approach, design and >>> usage of the pwrseq subsystem. Following issues are present in the RFC >>> at this moment but will be fixed later if the overall approach would be >>> viewed as acceptable: >>> >>> - No documentation >>> While the code tries to be self-documenting proper documentation >>> would be required. >>> >>> - Minimal device tree bindings changes >>> There are no proper updates for the DT bindings (thus neither Rob >>> Herring nor devicetree are included in the To/Cc lists). The dt >>> schema changes would be a part of v1. >>> >>> - Lack of proper PCIe integration >>> At this moment support for PCIe is hacked up to be able to test the >>> PCIe part of qca6390. Proper PCIe support would require automatically >>> powering up the devices before the scan basing on the proper device >>> structure in the device tree. >>> >>> ---------------------------------------------------------------- >>> Dmitry Baryshkov (15): >>> power: add power sequencer subsystem >>> pwrseq: port MMC's pwrseq drivers to new pwrseq subsystem >>> mmc: core: switch to new pwrseq subsystem >>> ath10k: add support for pwrseq sequencing >>> Bluetooth: hci_qca: merge qca_power into qca_serdev >>> Bluetooth: hci_qca: merge init paths >>> Bluetooth: hci_qca: merge qca_power_on with qca_regulators_init >>> Bluetooth: hci_qca: futher rework of power on/off handling >>> Bluetooth: hci_qca: add support for pwrseq >> >> any chance you can try to abandon patching hci_qca. The serdev support in hci_uart is rather hacking into old line discipline code and it is not aging well. It is really becoming a mess. > > I wanted to stay away from rewriting the BT code. But... New driver > would have a bonus point that I don't have to be compatible with old > bindings. In fact we can even make it the other way around: let the > old driver always use regulators and make the new driver support only > the pwrseq. Then it should be possible to drop the old hci_qca driver > together with dropping the old bindings. > >> I would say that the Qualcomm serial devices could use a separate standalone serdev driver. A while I send an RFC for a new serdev driver. >> >> https://www.spinics.net/lists/linux-bluetooth/msg74918.html > > Any reason why your driver stayed as an RFC and never made it into the > kernel? Do you plan to revive your old RFCs on H:4 and H:5? I was missing enough hardware to test it on and frankly I hoped that someone would pick up this work. The HCI line discipline “hack” needs to be removed soon. It is complicated, cumbersome and has a bunch of issues with locking. Mind you that originated in 2.4.6 kernel and is at its core bit-rotting. If you manage to put QCA support into a separate btqcauart driver, that would be awesome. The btmtkuart driver is another example where Mediatek got its own serdev based driver. Regards Marcel
