Hi Claudiu, On Wed, 5 Feb 2025 at 10:31, Claudiu <claudiu.beznea@xxxxxxxxx> wrote: > From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx> > > The Renesas RZ/G3S supports a power saving mode where power to most of the > SoC components is turned off. When returning from this power saving mode, > SoC components need to be re-configured. > > The SCIFs on the Renesas RZ/G3S need to be re-configured as well when > returning from this power saving mode. The sh-sci code already configures > the SCIF clocks, power domain and registers by calling uart_resume_port() > in sci_resume(). On suspend path the SCIF UART ports are suspended > accordingly (by calling uart_suspend_port() in sci_suspend()). The only > missing setting is the reset signal. For this assert/de-assert the reset > signal on driver suspend/resume. > > In case the no_console_suspend is specified by the user, the registers need > to be saved on suspend path and restore on resume path. To do this the > sci_console_save_restore() function was added. There is no need to > cache/restore the status or FIFO registers. Only the control registers. > The registers that will be saved/restored on suspend/resume are > specified by the struct sci_suspend_regs data structure. > > Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx> > --- > > The v4 of this patch was part of a series with 4 patches. As the rest of > the patches were applied I dropped the cover letter. The v4 cover letter > is located here: > https://lore.kernel.org/all/20250120130936.1080069-1-claudiu.beznea.uj@xxxxxxxxxxxxxx > > Changes in v5: > - fixed typo in patch description > - adjusted the patch description to reflect the new patch content > - added struct sci_suspend_regs and dropped the suspend_cacheable > flag introduced previously in struct plat_sci_reg; along with it > the updates in sci_port_params[] were also dropped; > also, the function (now sci_console_save_restore()) that saves > and restores the registers content was adjusted accordingly > - s/sci_console_setup/sci_console_save_restore/g Thanks for the update! > --- a/drivers/tty/serial/sh-sci.c > +++ b/drivers/tty/serial/sh-sci.c > @@ -3546,13 +3559,41 @@ static int sci_probe(struct platform_device *dev) > return 0; > } > > +static void sci_console_save_restore(struct sci_port *s, bool save) > +{ > + struct sci_suspend_regs *regs = &s->suspend_regs; > + struct uart_port *port = &s->port; > + > + if (save) { > + regs->scsmr = sci_serial_in(port, SCSMR); > + regs->scscr = sci_serial_in(port, SCSCR); > + regs->scfcr = sci_serial_in(port, SCFCR); > + regs->scsptr = sci_serial_in(port, SCSPTR); > + regs->scbrr = sci_serial_in(port, SCBRR); > + regs->semr = sci_serial_in(port, SEMR); The SCFCR, SCSPTR, and SEMR registers do not exist on all variants. Hence you should call sci_getreg() and check if plat_sci_reg.size is non-zero first, else you will trigger the WARN() in sci_serial_in(). > + } else { > + sci_serial_out(port, SCSMR, regs->scsmr); > + sci_serial_out(port, SCSCR, regs->scscr); > + sci_serial_out(port, SCFCR, regs->scfcr); > + sci_serial_out(port, SCSPTR, regs->scsptr); > + sci_serial_out(port, SCBRR, regs->scbrr); > + sci_serial_out(port, SEMR, regs->semr); Likewise for sci_serial_out(). > + } > +} Given there's nothing really shared anymore, I would split this in separate sci_console_save() and sci_console_restore() functions. The rest LGTM. 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
