On 21/06/19 9:12 AM, Baolin Wang wrote:
> For Spreadtrum SD host controller, we can not use standard SD registers
> to change and detect the I/O voltage signals, since our voltage regulator
> for I/O is fixed in hardware, and no signals were connected to the SD
> controller. Thus add Spreadtrum specific voltage switch ops to change
> voltage instead of using standard SD host registers.
>
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-sprd.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
> index 024c3c5..8b23c88 100644
> --- a/drivers/mmc/host/sdhci-sprd.c
> +++ b/drivers/mmc/host/sdhci-sprd.c
> @@ -403,6 +403,22 @@ static void sdhci_sprd_request(struct mmc_host *mmc, struct mmc_request *mrq)
> sdhci_request(mmc, mrq);
> }
>
> +static int sdhci_sprd_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
> +{
> + int ret;
> +
> + if (!IS_ERR(mmc->supply.vqmmc)) {
> + ret = mmc_regulator_set_vqmmc(mmc, ios);
> + if (ret) {
> + pr_err("%s: Switching signalling voltage failed\n",
> + mmc_hostname(mmc));
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> static void sdhci_sprd_hs400_enhanced_strobe(struct mmc_host *mmc,
> struct mmc_ios *ios)
> {
> @@ -470,6 +486,14 @@ static int sdhci_sprd_probe(struct platform_device *pdev)
> host->mmc_host_ops.request = sdhci_sprd_request;
> host->mmc_host_ops.hs400_enhanced_strobe =
> sdhci_sprd_hs400_enhanced_strobe;
> + /*
> + * We can not use the standard ops to change and detect the voltage
> + * signal for Spreadtrum SD host controller, since our voltage regulator
> + * for I/O is fixed in hardware, that means we do not need control
> + * the standard SD host controller to change the I/O voltage.
> + */
> + host->mmc_host_ops.start_signal_voltage_switch =
> + sdhci_sprd_voltage_switch;
>
> host->mmc->caps = MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED |
> MMC_CAP_ERASE | MMC_CAP_CMD23;
>
