Messages in this thread | | | Subject | Re: [PATCH V4 2/2] mmc: sdhci-msm: Use internal voltage control | From | Veerabhadrarao Badiganti <> | Date | Thu, 18 Jun 2020 12:00:05 +0530 |
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On 6/17/2020 7:46 PM, Ulf Hansson wrote: > On Wed, 17 Jun 2020 at 14:46, Veerabhadrarao Badiganti > <vbadigan@codeaurora.org> wrote: >> Thanks for comments Uffe. >> >> On 6/17/2020 3:04 PM, Ulf Hansson wrote: >>> On Tue, 16 Jun 2020 at 17:38, Veerabhadrarao Badiganti >>> <vbadigan@codeaurora.org> 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. >>>> >>>> IO-bus supply of eMMC would be kept always-on. So set the load >>>> for this supply to configure it in LPM when eMMC is suspend state >>>> and in HPM when eMMC is active. >>>> >>>> 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> >>>> --- >>>> drivers/mmc/host/sdhci-msm.c | 208 +++++++++++++++++++++++++++++++++++++++++-- >>>> 1 file changed, 199 insertions(+), 9 deletions(-) >>>> >>>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c >>>> index 15c42b059240..8297b2142748 100644 >>>> --- a/drivers/mmc/host/sdhci-msm.c >>>> +++ b/drivers/mmc/host/sdhci-msm.c >>>> @@ -37,7 +37,9 @@ >>>> #define CORE_PWRCTL_IO_LOW BIT(2) >>>> #define CORE_PWRCTL_IO_HIGH BIT(3) >>>> #define CORE_PWRCTL_BUS_SUCCESS BIT(0) >>>> +#define CORE_PWRCTL_BUS_FAIL BIT(1) >>>> #define CORE_PWRCTL_IO_SUCCESS BIT(2) >>>> +#define CORE_PWRCTL_IO_FAIL BIT(3) >>>> #define REQ_BUS_OFF BIT(0) >>>> #define REQ_BUS_ON BIT(1) >>>> #define REQ_IO_LOW BIT(2) >>>> @@ -127,6 +129,9 @@ >>>> /* Timeout value to avoid infinite waiting for pwr_irq */ >>>> #define MSM_PWR_IRQ_TIMEOUT_MS 5000 >>>> >>>> +/* Max load for eMMC Vdd-io supply */ >>>> +#define MMC_VQMMC_MAX_LOAD_UA 325000 >>>> + >>>> #define msm_host_readl(msm_host, host, offset) \ >>>> msm_host->var_ops->msm_readl_relaxed(host, offset) >>>> >>>> @@ -278,6 +283,7 @@ struct sdhci_msm_host { >>>> bool uses_tassadar_dll; >>>> u32 dll_config; >>>> u32 ddr_config; >>>> + bool vqmmc_enabled; >>>> }; >>>> >>>> static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host) >>>> @@ -1346,6 +1352,88 @@ 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) >>>> +{ >>>> + if (IS_ERR(mmc->supply.vmmc)) >>>> + return 0; >>>> + >>>> + return mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, mmc->ios.vdd); >>>> +} >>>> + >>>> +static int msm_toggle_vqmmc(struct sdhci_msm_host *msm_host, >>>> + struct mmc_host *mmc, bool level) >>>> +{ >>>> + int ret; >>>> + struct mmc_ios ios; >>>> + >>>> + if (msm_host->vqmmc_enabled == level) >>>> + return 0; >>>> + >>>> + 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 msm_config_vqmmc_mode(struct sdhci_msm_host *msm_host, >>>> + struct mmc_host *mmc, bool hpm) >>>> +{ >>>> + int load, ret; >>>> + >>>> + load = hpm ? MMC_VQMMC_MAX_LOAD_UA : 0; >>>> + ret = regulator_set_load(mmc->supply.vqmmc, load); >>>> + if (ret) >>>> + dev_err(mmc_dev(mmc), "%s: vqmmc set load failed: %d\n", >>>> + mmc_hostname(mmc), ret); >>>> + return ret; >>>> +} >>>> + >>>> +static int sdhci_msm_set_vqmmc(struct sdhci_msm_host *msm_host, >>>> + struct mmc_host *mmc, bool level) >>>> +{ >>>> + int ret; >>>> + bool always_on; >>>> + >>>> + if (IS_ERR(mmc->supply.vqmmc) || >>> White space. >>> >>>> + (mmc->ios.power_mode == MMC_POWER_UNDEFINED)) >>>> + return 0; >>>> + /* >>>> + * For eMMC don't turn off Vqmmc, Instead just configure it in LPM >>>> + * and HPM modes by setting the right amonut of load. >>> /s/right amonut of load/corresponding load >>> >>>> + */ >>>> + always_on = mmc->card && mmc_card_mmc(mmc->card); >>>> + >>>> + if (always_on) >>>> + ret = msm_config_vqmmc_mode(msm_host, mmc, level); >>>> + else >>>> + ret = msm_toggle_vqmmc(msm_host, mmc, level); >>> I am worried that this isn't really doing what you think it does. >>> always_on may not always be set for an eMMC. >>> >>> This is because the mmc->card doesn't get assigned until the >>> initialization of the eMMC has been completed. In other words, way >>> after VCC and VCCQ have been turned on and changed voltage levels. >> For the very first time, i have to enable the vqmmc. >> And second time on-wards I have to set load instead of turning vqmmc off >> / on. >> >> This condition helps me in doing exactly the same. >> >> This gets invoked first time when mmc_power_up() is called. >> Yes, by that time card won't be initialized. So this check fails and >> allows to turn on the regulator instead of setting load. >> >> After that, this gets invoked only next time mmc_power_up/off() is called >> which is during mmc_suspend/resume. > I see. > > That assumes the initialization always works at the first attempt, so > no re-try or power cycle gets done in some error/reset path. > >> By this time card is initialized, it allows to set load. > Okay, I get it. Thanks for clarifying. > > Perhaps you can add a small comment about this in the code, so we > don't forget the reasons why the code looks like this. Sure. Will update comment with this info. >> >>> Moreover, mmc_card_mmc() is also about legacy MMC cards, not solely for eMMCs. >> Okay. But on qcom platform, we have support for only eMMC/SD/SDIO. >> So this mmc_card_mmc() meets my requirements!!! Allows only eMMC not SD >> & SDIO. > Well, eMMC is fairly similar to MMC, from a basic functionality point > of view. So, I am quite sure you can get it to work with your > controller, even if it's not officially supported. >>> If you want special treatment of an eMMC, I think it's better to use >>> the DT bindings Documentation/devicetree/bindings/mmc/mmc-card.txt. If >>> you have such a subnode, that indicates that there is an eMMC card >>> attached. > That said, if you don't like the pure DT based solution, as I > suggested above - at least extend mmc_card_mmc() with checking the > MMC_CAP_NONREMOVABLE flag. sure. Will update it. Thank you. > > [...] > > Kind regards > Uffe
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