Hi Benjamin, Am Dienstag, dem 14.09.2021 um 17:46 +0200 schrieb Benjamin Gaignard: > Le 10/09/2021 à 22:26, Lucas Stach a écrit : > > This adds a driver for the blk-ctrl blocks found in the i.MX8M* line of > > SoCs. The blk-ctrl is a top-level peripheral located in the various *MIX > > power domains and interacts with the GPC power controller to provide the > > peripherals in the power domain access to the NoC and ensures that those > > peripherals are properly reset when their respective power domain is > > brought back to life. > > > > Software needs to do different things to make the bus handshake happen > > after the GPC *MIX domain is powered up and before it is powered down. > > As the requirements are quite different between the various blk-ctrls > > there is a callback function provided to hook in the proper sequence. > > > > The peripheral domains are quite uniform, they handle the soft clock > > enables and resets in the blk-ctrl address space and sequencing with the > > upstream GPC power domains. > > Hi Lucas, > > I have tried to use your patches for IMX8MQ but it seems that the hardware > have different architecture. > On IMX8MQ there is only one VPU domain for G1 and G2 and that doesn't match > with your implementation where it is needed to have "bus" and devices power domain. > From what I experiment in current IMX8MQ implementation of blk-ctrl (inside VPU driver) > enabling the 3 clocks (bus, G1, G2) is needed to reset the VPUs. > > Do you think you can update your design to take care of these hardware variations ? The clocking/reset of the blk-ctrl and ADB in the i.MX8MQ VPU power domain is really a bit strange, as the ADB reset is tied to the VPU resets and the clk-ctrl seem to require all 3 VPU clocks, instead of only the bus clock as in newer designs. However I was able to make it work with the existing blk-ctrl driver design. My current WIP patches (only tested with the G1 core so far) on top of the v5 of the series I just sent out can be found here: https://git.pengutronix.de/cgit/lst/linux/log/?h=imx8mq-vpu-blk-ctrl Hope this helps. Regards, Lucas
