Re: [PATCH V1 3/3] mmc: sdhci: Allow platform controlled voltage switching

[Veerabhadrarao Badiganti]

On 5/19/2020 11:36 AM, Adrian Hunter wrote:

On 15/05/20 2:18 pm, Veerabhadrarao Badiganti wrote:

From: Vijay Viswanath <vvisw...@codeaurora.org>

If vendor platform drivers are controlling whole logic of voltage
switching, then sdhci driver no need control vqmmc regulator.
So skip enabling/disable vqmmc from SDHC driver.

Signed-off-by: Vijay Viswanath <vvisw...@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadi...@codeaurora.org>
---
  drivers/mmc/host/sdhci.c | 32 +++++++++++++++++++-------------
  drivers/mmc/host/sdhci.h |  1 +
  2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 1bb6b67..c010823 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -4098,6 +4098,7 @@ int sdhci_setup_host(struct sdhci_host *host)
        unsigned int override_timeout_clk;
        u32 max_clk;
        int ret;
+       bool enable_vqmmc = false;

WARN_ON(host == NULL);

        if (host == NULL)
@@ -4111,9 +4112,12 @@ int sdhci_setup_host(struct sdhci_host *host)
         * the host can take the appropriate action if regulators are not
         * available.
         */
-       ret = mmc_regulator_get_supply(mmc);
-       if (ret)
-               return ret;
+       if (!mmc->supply.vqmmc) {
+               ret = mmc_regulator_get_supply(mmc);
+               if (ret)
+                       return ret;
+               enable_vqmmc  = true;
+       }

DBG("Version: 0x%08x | Present: 0x%08x\n",

            sdhci_readw(host, SDHCI_HOST_VERSION),
@@ -4373,7 +4377,15 @@ int sdhci_setup_host(struct sdhci_host *host)
                mmc->caps |= MMC_CAP_NEEDS_POLL;

if (!IS_ERR(mmc->supply.vqmmc)) {

-               ret = regulator_enable(mmc->supply.vqmmc);
+               if (enable_vqmmc) {
+                       ret = regulator_enable(mmc->supply.vqmmc);
+                       if (ret) {
+                               pr_warn("%s: Failed to enable vqmmc regulator: 
%d\n",
+                                       mmc_hostname(mmc), ret);
+                               mmc->supply.vqmmc = ERR_PTR(-EINVAL);
+                       }
+                       host->vqmmc_enabled = !ret;
+               }

/* If vqmmc provides no 1.8V signalling, then there's no UHS */

                if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 1700000,
@@ -4386,12 +4398,6 @@ int sdhci_setup_host(struct sdhci_host *host)
                if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 2700000,
                                                    3600000))
                        host->flags &= ~SDHCI_SIGNALING_330;
-
-               if (ret) {
-                       pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
-                               mmc_hostname(mmc), ret);
-                       mmc->supply.vqmmc = ERR_PTR(-EINVAL);
-               }
        }

if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) {

@@ -4625,7 +4631,7 @@ int sdhci_setup_host(struct sdhci_host *host)
        return 0;

unreg:

-       if (!IS_ERR(mmc->supply.vqmmc))
+       if (host->vqmmc_enabled)
                regulator_disable(mmc->supply.vqmmc);
  undma:
        if (host->align_buffer)
@@ -4643,7 +4649,7 @@ void sdhci_cleanup_host(struct sdhci_host *host)
  {
        struct mmc_host *mmc = host->mmc;

- if (!IS_ERR(mmc->supply.vqmmc))

+       if (host->vqmmc_enabled)
                regulator_disable(mmc->supply.vqmmc);

if (host->align_buffer)

@@ -4780,7 +4786,7 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)

destroy_workqueue(host->complete_wq); - if (!IS_ERR(mmc->supply.vqmmc))

+       if (host->vqmmc_enabled)
                regulator_disable(mmc->supply.vqmmc);

if (host->align_buffer)

diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 8d2a096..24d27e1 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -570,6 +570,7 @@ struct sdhci_host {
        u32 caps1;              /* CAPABILITY_1 */
        bool read_caps;         /* Capability flags have been read */

+ bool vqmmc_enabled; /* Vqmmc is enabled */

Last time around there was dissatisfaction with this variable name.  Perhaps
change it to sdhci_core_to_disable_vqmmc

Sure Adrian. Will update this variable name.

        unsigned int            ocr_avail_sdio; /* OCR bit masks */
        unsigned int            ocr_avail_sd;
        unsigned int            ocr_avail_mmc;