(Resent to all recipients) On Fri, May 21, 2021 at 8:01 PM Nicolas Boichat <drinkcat@xxxxxxxxxxxx> wrote: > > Add a basic GPU node for mt8183, as well as OPP table. > > Note that with the current panfrost driver, devfreq is not > actually functional, as the we do not have platform-specific > support for >1 supplies. Also, we are missing code to handle > frequency change, as the GPU frequency needs to be switched > away to a stable 26Mhz clock during the transition. > > Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx> > --- > The binding we use with out-of-tree Mali drivers includes more > clocks, this is used for devfreq: the out-of-tree driver switches > clk_mux to clk_sub_parent (26Mhz), adjusts clk_main_parent, then > switches clk_mux back to clk_main_parent: > (see https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.19/drivers/gpu/arm/midgard/platform/mediatek/mali_kbase_runtime_pm.c#423) > clocks = > <&topckgen CLK_TOP_MFGPLL_CK>, > <&topckgen CLK_TOP_MUX_MFG>, > <&clk26m>, > <&mfgcfg CLK_MFG_BG3D>; > clock-names = > "clk_main_parent", > "clk_mux", > "clk_sub_parent", > "subsys_mfg_cg"; > (based on discussions, this probably belongs in the clock core) > > This only matters for devfreq, that is disabled anyway as we don't > have platform-specific code to handle >1 supplies. Yes. This can be done with clk_notifiers. See https://elixir.bootlin.com/linux/latest/source/drivers/clk/sunxi-ng/ccu_mux.c#L261 for such an example. ChenYu
