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

From: Adrian Hunter
Date: Tue May 19 2020 - 02:06:35 EST


On 15/05/20 2:18 pm, Veerabhadrarao Badiganti wrote:
> From: Vijay Viswanath <vviswana@xxxxxxxxxxxxxx>
>
> 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 <vviswana@xxxxxxxxxxxxxx>
> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@xxxxxxxxxxxxxx>
> ---
> 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

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