Hi,
On Tue, Mar 1, 2022 at 6:05 PM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>
> On 28/02/2022 19:03, Ulf Hansson wrote:
> > On Fri, 25 Feb 2022 at 13:56, Ben Chuang <benchuanggli@xxxxxxxxx> wrote:
> >>
> >> From: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
> >>
> >> Add runtime PM for GL9763E and disable PLL in runtime suspend. So power
> >> gated of upstream port can be enabled.
> >>
> >> Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
> >> Tested-by: Kevin Chang <kevin.chang@xxxxxxxxxxxxxxxxxx>
> >> ---
> >> drivers/mmc/host/sdhci-pci-gli.c | 54 ++++++++++++++++++++++++++++++++
> >> 1 file changed, 54 insertions(+)
> >>
> >> diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
> >> index 97035d77c18c..cf99b6af792d 100644
> >> --- a/drivers/mmc/host/sdhci-pci-gli.c
> >> +++ b/drivers/mmc/host/sdhci-pci-gli.c
> >> @@ -873,6 +873,55 @@ static void gli_set_gl9763e(struct sdhci_pci_slot *slot)
> >> pci_write_config_dword(pdev, PCIE_GLI_9763E_VHS, value);
> >> }
> >>
> >> +#ifdef CONFIG_PM
> >> +static int gl9763e_runtime_suspend(struct sdhci_pci_chip *chip)
> >> +{
> >> + struct sdhci_pci_slot *slot = chip->slots[0];
> >> + struct sdhci_host *host = slot->host;
> >> + u16 clock;
> >> +
> >> + clock = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> >> + clock &= ~(SDHCI_CLOCK_PLL_EN | SDHCI_CLOCK_CARD_EN);
> >> + sdhci_writew(host, clock, SDHCI_CLOCK_CONTROL);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int gl9763e_runtime_resume(struct sdhci_pci_chip *chip)
> >> +{
> >> + struct sdhci_pci_slot *slot = chip->slots[0];
> >> + struct sdhci_host *host = slot->host;
> >> + ktime_t timeout;
> >> + u16 clock;
> >> +
> >> + clock = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> >> +
> >> + clock |= SDHCI_CLOCK_PLL_EN;
> >> + clock &= ~SDHCI_CLOCK_INT_STABLE;
> >> + sdhci_writew(host, clock, SDHCI_CLOCK_CONTROL);
> >> +
> >> + timeout = ktime_add_ms(ktime_get(), 150);
> >> + while (1) {
> >> + bool timedout = ktime_after(ktime_get(), timeout);
> >> +
> >> + clock = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> >> + if (clock & SDHCI_CLOCK_INT_STABLE)
> >> + break;
> >> + if (timedout) {
> >> + pr_err("%s: PLL clock never stabilised.\n",
> >> + mmc_hostname(host->mmc));
> >> + sdhci_dumpregs(host);
> >> + break;
> >> + }
> >> + udelay(10);
> >> + }
>
> Could use something like read_poll_timeout() here e.g.
>
> if (read_poll_timeout(sdhci_readw, clk, (clk & SDHCI_CLOCK_INT_STABLE),
> 1000, 150000, false, host, SDHCI_CLOCK_CONTROL)) {
> pr_err("%s: PLL clock never stabilised.\n",
> mmc_hostname(host->mmc));
> sdhci_dumpregs(host);
> }
>
>
Thanks for the tip. I will prepare the next patch.
> >> + clock |= SDHCI_CLOCK_CARD_EN;
> >> + sdhci_writew(host, clock, SDHCI_CLOCK_CONTROL);
> >> +
> >> + return 0;
> >> +}
> >
> > Both functions above look very similar to what sdhci_set_clock() does.
> > Can you use that, rather than open coding the above?
> >
The codes turn on/off the clock but it doesn't change the clock.
Using sdhci_set_clock() needs to store the clock value because it
clears the clock.
> > Other than that, I would appreciate it if Adrian could have a look at
> > this too. For example, I wonder if perhaps
> > sdhci_runtime_suspend|resume_host() should be called in these paths
> > too.
>
> Assuming the host controller does not lose state information, it should be fine.
>
Yes, the host always has aux. power and keep state.
Thank you both for your comments.
> >
> >> +#endif
> >> +
> >> static int gli_probe_slot_gl9763e(struct sdhci_pci_slot *slot)
> >> {
> >> struct pci_dev *pdev = slot->chip->pdev;
> >> @@ -982,6 +1031,11 @@ const struct sdhci_pci_fixes sdhci_gl9763e = {
> >> #ifdef CONFIG_PM_SLEEP
> >> .resume = sdhci_cqhci_gli_resume,
> >> .suspend = sdhci_cqhci_gli_suspend,
> >> +#endif
> >> +#ifdef CONFIG_PM
> >> + .runtime_suspend = gl9763e_runtime_suspend,
> >> + .runtime_resume = gl9763e_runtime_resume,
> >> + .allow_runtime_pm = true,
> >> #endif
> >> .add_host = gl9763e_add_host,
> >> };
> >> --
> >> 2.35.1
> >>
> >
> > Kind regards
> > Uffe
>
Best regards,
Ben
