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Message-ID: <aa19cd49-b29c-a785-6904-85b9fad93208@codeaurora.org>
Date: Thu, 27 Sep 2018 19:43:04 +0530
From: Veerabhadrarao Badiganti <vbadigan@...eaurora.org>
To: Evan Green <evgreen@...omium.org>
Cc: adrian.hunter@...el.com, Ulf Hansson <ulf.hansson@...aro.org>,
robh+dt@...nel.org, linux-mmc@...r.kernel.org,
asutoshd@...eaurora.org, riteshh@...eaurora.org,
stummala@...eaurora.org, sayali <sayalil@...eaurora.org>,
Doug Anderson <dianders@...gle.com>, vviswana@...eaurora.org,
venkatg@...eaurora.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH V2 3/3] mmc: sdhci-msm: Use internal voltage control
On 9/22/2018 1:39 AM, Evan Green wrote:
> On Wed, Sep 19, 2018 at 11:24 PM Veerabhadrarao Badiganti
> <vbadigan@...eaurora.org> wrote:
>> From: Vijay Viswanath <vviswana@...eaurora.org>
>>
>> Some sdhci-msm controllers require that 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 quirk for internal voltage switching and then control the
>> voltage switching using power irq.
>>
>> Signed-off-by: Asutosh Das <asutoshd@...eaurora.org>
>> Signed-off-by: Venkat Gopalakrishnan <venkatg@...eaurora.org>
>> Signed-off-by: Vijay Viswanath <vviswana@...eaurora.org>
>> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@...eaurora.org>
>> ---
>> drivers/mmc/host/sdhci-msm.c | 211 +++++++++++++++++++++++++++++++++++++++++--
>> 1 file changed, 203 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>> index 3cc8bfe..486462d 100644
>> --- a/drivers/mmc/host/sdhci-msm.c
>> +++ b/drivers/mmc/host/sdhci-msm.c
>> @@ -43,7 +43,9 @@
>> #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)
>> @@ -258,6 +260,10 @@ struct sdhci_msm_host {
>> bool mci_removed;
>> const struct sdhci_msm_variant_ops *var_ops;
>> const struct sdhci_msm_offset *offset;
>> + bool vmmc_load;
>> + u32 vmmc_level[2];
>> + bool vqmmc_load;
>> + u32 vqmmc_level[2];
>> };
>>
>> static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
>> @@ -1211,6 +1217,74 @@ static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host,
>> sdhci_msm_hs400(host, &mmc->ios);
>> }
>>
>> +static int sdhci_msm_set_vmmc(struct sdhci_msm_host *msm_host,
>> + struct mmc_host *mmc, int level)
>> +{
>> + int load = msm_host->vmmc_level[level];
>> + int ret;
>> +
>> + if (IS_ERR(mmc->supply.vmmc))
>> + return 0;
>> +
>> + if (msm_host->vmmc_load) {
>> + ret = regulator_set_load(mmc->supply.vmmc, load);
>> + if (ret)
>> + goto out;
>> + }
>> +
>> + ret = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, mmc->ios.vdd);
> This is new, isn't it? Could you explain why this is needed?
This sets the regulator voltage to supplied value and
enables/disables the regulator.
>
>> +out:
>> + if (ret)
>> + pr_err("%s: vmmc set load/ocr 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, int level)
>> +{
>> + int load = msm_host->vqmmc_level[level];
>> + int ret;
>> + struct mmc_ios ios;
>> +
>> + if (IS_ERR(mmc->supply.vqmmc))
>> + return 0;
>> +
>> + if (msm_host->vqmmc_load) {
>> + ret = regulator_set_load(mmc->supply.vqmmc, load);
>> + if (ret)
>> + goto out;
>> + }
>> +
>> + /*
>> + * The IO voltage regulator maynot always support a voltage close to
> s/maynot/may not/
>
>> + * vdd. Set IO voltage based on capability of the regulator.
> remove extra space between on and capability.
>
>> + */
>> + if (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) {
>> + pr_debug("%s: %s: setting signal voltage: %d\n",
>> + mmc_hostname(mmc), __func__,
>> + ios.signal_voltage);
>> + ret = mmc_regulator_set_vqmmc(mmc, &ios);
>> + if (ret)
>> + goto out;
>> + }
>> + ret = regulator_enable(mmc->supply.vqmmc);
>> + } else {
>> + ret = regulator_disable(mmc->supply.vqmmc);
>> + }
>> +out:
>> + if (ret)
>> + pr_err("%s: vqmmc failed: %d\n", mmc_hostname(mmc), ret);
>> +
>> + return ret;
>> +}
>> +
>> static inline void sdhci_msm_init_pwr_irq_wait(struct sdhci_msm_host *msm_host)
>> {
>> init_waitqueue_head(&msm_host->pwr_irq_wait);
>> @@ -1314,8 +1388,9 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
>> {
>> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> + struct mmc_host *mmc = host->mmc;
>> u32 irq_status, irq_ack = 0;
>> - int retry = 10;
>> + int retry = 10, ret = 0;
>> u32 pwr_state = 0, io_level = 0;
>> u32 config;
>> const struct sdhci_msm_offset *msm_offset = msm_host->offset;
>> @@ -1351,14 +1426,34 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
>>
>> /* Handle BUS ON/OFF*/
>> if (irq_status & CORE_PWRCTL_BUS_ON) {
>> - pwr_state = REQ_BUS_ON;
>> - io_level = REQ_IO_HIGH;
>> - irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
>> + ret = sdhci_msm_set_vmmc(msm_host, mmc, 1);
>> + if (!ret)
>> + ret = sdhci_msm_set_vqmmc(msm_host, mmc, 1);
> Should you put vmmc back to 0 if setting vqmmc to 1 fails?
Yeah, will set to back to 0.
>
>> +
>> + if (!ret) {
>> + pwr_state = REQ_BUS_ON;
>> + io_level = REQ_IO_HIGH;
>> + irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
>> + } else {
>> + pr_err("%s: BUS_ON req failed(%d). irq_status: 0x%08x\n",
>> + mmc_hostname(mmc), ret, irq_status);
>> + irq_ack |= CORE_PWRCTL_BUS_FAIL;
>> + }
>> }
>> if (irq_status & CORE_PWRCTL_BUS_OFF) {
>> - pwr_state = REQ_BUS_OFF;
>> - io_level = REQ_IO_LOW;
>> - irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
>> + ret = sdhci_msm_set_vmmc(msm_host, mmc, 0);
>> + if (!ret)
>> + ret = sdhci_msm_set_vqmmc(msm_host, mmc, 0);
>> +
>> + if (!ret) {
>> + pwr_state = REQ_BUS_OFF;
>> + io_level = REQ_IO_LOW;
>> + irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
>> + } else {
>> + pr_err("%s: BUS_ON req failed(%d). irq_status: 0x%08x\n",
>> + mmc_hostname(mmc), ret, irq_status);
>> + irq_ack |= CORE_PWRCTL_BUS_FAIL;
>> + }
>> }
>> /* Handle IO LOW/HIGH */
>> if (irq_status & CORE_PWRCTL_IO_LOW) {
>> @@ -1370,6 +1465,15 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
>> irq_ack |= CORE_PWRCTL_IO_SUCCESS;
>> }
>>
>> + if (io_level && !IS_ERR(mmc->supply.vqmmc) && !pwr_state) {
>> + ret = mmc_regulator_set_vqmmc(mmc, &mmc->ios);
>> + if (ret)
>> + pr_err("%s: IO_level setting failed(%d). signal_voltage: %d, vdd: %d irq_status: 0x%08x\n",
>> + mmc_hostname(mmc), ret,
>> + mmc->ios.signal_voltage, mmc->ios.vdd,
>> + irq_status);
>> + }
>> +
>> /*
>> * The driver has to acknowledge the interrupt, switch voltages and
>> * report back if it succeded or not to this register. The voltage
>> @@ -1605,6 +1709,91 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
>> pr_debug("%s: supported caps: 0x%08x\n", mmc_hostname(mmc), caps);
>> }
>>
>> +static int sdhci_msm_register_vreg(struct sdhci_msm_host *msm_host)
>> +{
>> + int ret = 0;
>> +
>> + ret = mmc_regulator_get_supply(msm_host->mmc);
>> + if (ret)
>> + return ret;
>> + if (device_property_read_u32_array(&msm_host->pdev->dev,
>> + "qcom,vmmc-current-level-microamp",
>> + msm_host->vmmc_level, 2) >= 0)
>> + msm_host->vmmc_load = true;
>> + if (device_property_read_u32_array(&msm_host->pdev->dev,
>> + "qcom,vqmmc-current-level-microamp",
>> + msm_host->vqmmc_level, 2) >= 0)
>> + msm_host->vqmmc_load = true;
>> +
>> + sdhci_msm_set_regulator_caps(msm_host);
>> +
>> + return 0;
>> +
>> +}
>> +
>> +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;
>> +
>> + /*
>> + * 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;
>> + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
>> +
>> + /* 3.3V regulator output should be stable within 5 ms */
>> + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> + if (!(ctrl & SDHCI_CTRL_VDD_180))
>> + return 0;
>> +
>> + pr_warn("%s: 3.3V regulator output did not became stable\n",
>> + mmc_hostname(mmc));
>> +
>> + return -EAGAIN;
>> + 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;
>> + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
>> +
>> + /* 1.8V regulator output should be stable within 5 ms */
>> + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> + if (ctrl & SDHCI_CTRL_VDD_180)
>> + return 0;
>> +
>> + pr_warn("%s: 1.8V regulator output did not became stable\n",
>> + mmc_hostname(mmc));
>> +
>> + return -EAGAIN;
>> + case MMC_SIGNAL_VOLTAGE_120:
>> + if (!(host->flags & SDHCI_SIGNALING_120))
>> + return -EINVAL;
> So the state of SDHCI_CTRL_VDD_180 doesn't matter when trying to set
> 1.2V? I tried looking at the SDHC spec, but it was similarly silent
> about 1.2V. So I guess it's fine?
Right.
But SDHCI_SIGNALING_120 gets set only if the the vqmmc regulator
supports 1.2v. On all msm platforms, the minimum voltage of vqmmc is 1.8v
only. So 1.2v is not supported on sdhci-msm platforms.
>
>
>> + return 0;
>> + default:
>> + /* No signal voltage switch required */
>> + return 0;
>> + }
>> +
>> +}
>> +
>> static const struct sdhci_msm_variant_ops mci_var_ops = {
>> .msm_readl_relaxed = sdhci_msm_mci_variant_readl_relaxed,
>> .msm_writel_relaxed = sdhci_msm_mci_variant_writel_relaxed,
>> @@ -1644,6 +1833,7 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
>> .set_uhs_signaling = sdhci_msm_set_uhs_signaling,
>> .write_w = sdhci_msm_writew,
>> .write_b = sdhci_msm_writeb,
>> + .set_power = sdhci_set_power_noreg,
>> };
>>
>> static const struct sdhci_pltfm_data sdhci_msm_pdata = {
>> @@ -1818,6 +2008,10 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>> msm_offset->core_vendor_spec_capabilities0);
>> }
>>
>> + ret = sdhci_msm_register_vreg(msm_host);
>> + if (ret)
>> + goto clk_disable;
>> +
>> /*
>> * Power on reset state may trigger power irq if previous status of
>> * PWRCTL was either BUS_ON or IO_HIGH_V. So before enabling pwr irq
>> @@ -1862,11 +2056,12 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>> MSM_MMC_AUTOSUSPEND_DELAY_MS);
>> pm_runtime_use_autosuspend(&pdev->dev);
>>
>> + host->mmc_host_ops.start_signal_voltage_switch =
>> + sdhci_msm_start_signal_voltage_switch;
>> host->mmc_host_ops.execute_tuning = sdhci_msm_execute_tuning;
>> ret = sdhci_add_host(host);
>> if (ret)
>> goto pm_runtime_disable;
>> - sdhci_msm_set_regulator_caps(msm_host);
>>
>> pm_runtime_mark_last_busy(&pdev->dev);
>> pm_runtime_put_autosuspend(&pdev->dev);
>> --
>> Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc., is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
>>
Thanks,
Veeera
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