On Wed, Jan 10, 2024 at 2:15 AM Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx> wrote: > Some boards might use Linux and another OS at the same time. In such > case, currently, during booting, Linux will stop necessary module clocks > which are not used on the Linux side, but are used by another OS. > > To avoid such situation, renesas-cpg-mssr tries to find > status = "reserved" devices (A), and adds CLK_IGNORE_UNUSED flag to its > <&cgp CPG_MOD xxx> clock (B). > > Table 2.4: Values for status property > https://github.com/devicetree-org/devicetree-specification/releases/download/v0.4/devicetree-specification-v0.4.pdf > > "reserved" > Indicates that the device is operational, but should not be > used. Typically this is used for devices that are controlled > by another software component, such as platform firmware. > > ex) > scif5: serial@e6f30000 { > ... > (B) clocks = <&cpg CPG_MOD 202>, > <&cpg CPG_CORE R8A7795_CLK_S3D1>, > <&scif_clk>; > ... > (A) status = "reserved"; > }; > > Cc: Aymeric Aillet <aymeric.aillet@xxxxxxx> > Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx> > Tested-by: Yusuke Goda <yusuke.goda.sx@xxxxxxxxxxx> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
