Re: [PATCH V2 2/3] mmc: sdhci-msm: Use internal voltage control
From: Veerabhadrarao Badiganti
Date: Fri May 22 2020 - 09:27:46 EST
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@xxxxxxxxxxxxxx>
Signed-off-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
Co-developed-by: Vijay Viswanath <vviswana@xxxxxxxxxxxxxx>
Signed-off-by: Vijay Viswanath <vviswana@xxxxxxxxxxxxxx>
Co-developed-by: Veerabhadrarao Badiganti <vbadigan@xxxxxxxxxxxxxx>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@xxxxxxxxxxxxxx>
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