Messages in this thread | | | Subject | Re: [PATCH V2 2/3] mmc: sdhci-msm: Use internal voltage control | From | Veerabhadrarao Badiganti <> | Date | Fri, 22 May 2020 18:57:23 +0530 |
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Hi Bjorn,
On 5/22/2020 12:37 AM, Bjorn Andersson wrote: > On Thu 21 May 08:23 PDT 2020, Veerabhadrarao Badiganti wrote: > >> On qcom SD host controllers voltage switching be done after the HW >> is ready for it. The HW informs its readiness through power irq. >> The voltage switching should happen only then. >> >> Use the internal voltage switching and then control the voltage >> switching using power irq. >> >> Set the regulator load as well so that regulator can be configured >> in LPM mode when in is not being used. >> >> Co-developed-by: Asutosh Das <asutoshd@codeaurora.org> >> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org> >> Co-developed-by: Vijay Viswanath <vviswana@codeaurora.org> >> Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org> >> Co-developed-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org> >> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org> > Looks better, thanks. > >> --- >> drivers/mmc/host/sdhci-msm.c | 207 +++++++++++++++++++++++++++++++++++++++++-- >> 1 file changed, 198 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c > [..] >> static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host) >> @@ -1298,6 +1302,71 @@ static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host, >> sdhci_msm_hs400(host, &mmc->ios); >> } >> >> +static int sdhci_msm_set_vmmc(struct mmc_host *mmc) >> +{ >> + int ret; >> + >> + if (IS_ERR(mmc->supply.vmmc)) >> + return 0; >> + >> + ret = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, mmc->ios.vdd); >> + if (ret) >> + dev_err(mmc_dev(mmc), "%s: vmmc set ocr with vdd=%d failed: %d\n", >> + mmc_hostname(mmc), mmc->ios.vdd, ret); > Missed this one on v1, in the event that mmc_regulator_set_ocr() return > a non-zero value it has already printed an error message. So please > replace the tail with just: > > return mmc_regulator_set_ocr(...); > >> + >> + return ret; >> +} >> + >> +static int sdhci_msm_set_vqmmc(struct sdhci_msm_host *msm_host, >> + struct mmc_host *mmc, bool level) >> +{ >> + int load, ret; >> + struct mmc_ios ios; >> + >> + if (IS_ERR(mmc->supply.vqmmc) || >> + (mmc->ios.power_mode == MMC_POWER_UNDEFINED) || >> + (msm_host->vqmmc_enabled == level)) >> + return 0; >> + >> + if (msm_host->vqmmc_load) { >> + load = level ? msm_host->vqmmc_load : 0; >> + ret = regulator_set_load(mmc->supply.vqmmc, load); > Sorry for the late reply on v1, but please see my explanation regarding > load and always-on regulators there.
<Merging your comment from V1 here>
>> You should still call regulator_enable()/regulator_disable() on your >> consumer regulator in this driver. When you do this the regulator core >> will conclude that the regulator_dev (i.e. the part that represents the >> hardware) is marked always_on and will not enable/disable the regulator.
>> But it will still invoke _regulator_handle_consumer_enable() and >> _regulator_handle_consumer_disable(), which will aggregate the "load" of >> all client regulators and update the regulator's load.
>> So this will apply the load as you expect regardless of it being >> supplied by a regulator marked as always_on.
Since I'm not turning off this regulator for eMMC, I wanted to keep it in LPM mode to save some power. When the regulator configured in auto mode (RPMH_REGULATOR_MODE_AUTO) it switches to LPM/HPM mode based on the active load. So i have to minimize my driver load requirement so that I can let this regulator in LPM mode. So i need to set load every-time I disable/enable the regulator.
>> + if (ret) { >> + dev_err(mmc_dev(mmc), "%s: vqmmc set load failed: %d\n", >> + mmc_hostname(mmc), ret); >> + goto out; >> + } >> + } >> + >> + if (level) { >> + /* Set the IO voltage regulator to default voltage level */ >> + if (msm_host->caps_0 & CORE_3_0V_SUPPORT) >> + ios.signal_voltage = MMC_SIGNAL_VOLTAGE_330; >> + else if (msm_host->caps_0 & CORE_1_8V_SUPPORT) >> + ios.signal_voltage = MMC_SIGNAL_VOLTAGE_180; >> + >> + if (msm_host->caps_0 & CORE_VOLT_SUPPORT) { >> + ret = mmc_regulator_set_vqmmc(mmc, &ios); >> + if (ret < 0) { >> + dev_err(mmc_dev(mmc), "%s: vqmmc set volgate failed: %d\n", >> + mmc_hostname(mmc), ret); >> + goto out; >> + } >> + } >> + ret = regulator_enable(mmc->supply.vqmmc); >> + } else { >> + ret = regulator_disable(mmc->supply.vqmmc); >> + } >> + >> + if (ret) >> + dev_err(mmc_dev(mmc), "%s: vqmm %sable failed: %d\n", >> + mmc_hostname(mmc), level ? "en":"dis", ret); >> + else >> + msm_host->vqmmc_enabled = level; >> +out: >> + return ret; >> +} > [..] >> +static int sdhci_msm_start_signal_voltage_switch(struct mmc_host *mmc, >> + struct mmc_ios *ios) >> +{ >> + struct sdhci_host *host = mmc_priv(mmc); >> + u16 ctrl, status; >> + >> + /* >> + * Signal Voltage Switching is only applicable for Host Controllers >> + * v3.00 and above. >> + */ >> + if (host->version < SDHCI_SPEC_300) >> + return 0; >> + >> + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); >> + >> + switch (ios->signal_voltage) { >> + case MMC_SIGNAL_VOLTAGE_330: >> + if (!(host->flags & SDHCI_SIGNALING_330)) >> + return -EINVAL; >> + >> + /* Set 1.8V Signal Enable in the Host Control2 register to 0 */ >> + ctrl &= ~SDHCI_CTRL_VDD_180; >> + break; >> + case MMC_SIGNAL_VOLTAGE_180: >> + if (!(host->flags & SDHCI_SIGNALING_180)) >> + return -EINVAL; >> + >> + /* >> + * Enable 1.8V Signal Enable in the Host Control2 >> + * register >> + */ >> + ctrl |= SDHCI_CTRL_VDD_180; >> + break; >> + case MMC_SIGNAL_VOLTAGE_120: >> + if (!(host->flags & SDHCI_SIGNALING_120)) >> + return -EINVAL; >> + return 0; >> + default: >> + /* No signal voltage switch required */ >> + return 0; >> + } >> + >> + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2); >> + >> + /* Wait for 5ms */ >> + usleep_range(5000, 5500); >> + >> + /* regulator output should be stable within 5 ms */ >> + status = !!(ctrl & SDHCI_CTRL_VDD_180); >> + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); >> + if (!!(ctrl & SDHCI_CTRL_VDD_180) == status) > You should be able to drop the !! both here and when assigning status. > > Overall this looks neater, thanks for reworking it. > > Regards, > Bjorn
Thanks
Veera
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