On 21/06/18 15:23, Vijay Viswanath wrote:
> Some controllers can have internal mechanism to inform the SW that it
> is ready for voltage switching. For such controllers, changing voltage
> before the HW is ready can result in various issues.
>
> Add a quirk, which can be used by drivers of such controllers.
>
> Signed-off-by: Vijay Viswanath <[email protected]>
> ---
> drivers/mmc/host/sdhci.c | 20 +++++++++++++++-----
> drivers/mmc/host/sdhci.h | 2 ++
> 2 files changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 1c828e0..f0346d4 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1615,7 +1615,8 @@ void sdhci_set_power_noreg(struct sdhci_host *host,
> unsigned char mode,
> void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> unsigned short vdd)
> {
> - if (IS_ERR(host->mmc->supply.vmmc))
> + if (IS_ERR(host->mmc->supply.vmmc) ||
> + (host->quirks2 & SDHCI_QUIRK2_INTERNAL_PWR_CTL))
I think you should provide your own ->set_power() instead of this
> sdhci_set_power_noreg(host, mode, vdd);
> else
> sdhci_set_power_reg(host, mode, vdd);
> @@ -2009,7 +2010,9 @@ int sdhci_start_signal_voltage_switch(struct mmc_host
> *mmc,
> ctrl &= ~SDHCI_CTRL_VDD_180;
> sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
>
> - if (!IS_ERR(mmc->supply.vqmmc)) {
> + if (!IS_ERR(mmc->supply.vqmmc) &&
> + !(host->quirks2 &
> + SDHCI_QUIRK2_INTERNAL_PWR_CTL)) {
And your own ->start_signal_voltage_switch()
> ret = mmc_regulator_set_vqmmc(mmc, ios);
> if (ret) {
> pr_warn("%s: Switching to 3.3V signalling
> voltage failed\n",
> @@ -2032,7 +2035,8 @@ int sdhci_start_signal_voltage_switch(struct mmc_host
> *mmc,
> case MMC_SIGNAL_VOLTAGE_180:
> if (!(host->flags & SDHCI_SIGNALING_180))
> return -EINVAL;
> - if (!IS_ERR(mmc->supply.vqmmc)) {
> + if (!IS_ERR(mmc->supply.vqmmc) &&
> + !(host->quirks2 & SDHCI_QUIRK2_INTERNAL_PWR_CTL)) {
> ret = mmc_regulator_set_vqmmc(mmc, ios);
> if (ret) {
> pr_warn("%s: Switching to 1.8V signalling
> voltage failed\n",
> @@ -3485,7 +3489,10 @@ 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 (!(host->quirks2 & SDHCI_QUIRK2_INTERNAL_PWR_CTL))
Since we expect mmc_regulator_get_supply() to have been called, this could be:
if (!mmc->supply.vmmc) {
ret = mmc_regulator_get_supply(mmc);
enable_vqmmc = true;
} else {
ret = 0;
}
> + ret = mmc_regulator_get_supply(mmc);
> + else
> + ret = 0;
> if (ret)
> return ret;
>
> @@ -3736,7 +3743,10 @@ int sdhci_setup_host(struct sdhci_host *host)
>
> /* If vqmmc regulator and no 1.8V signalling, then there's no UHS */
> if (!IS_ERR(mmc->supply.vqmmc)) {
> - ret = regulator_enable(mmc->supply.vqmmc);
> + if (!(host->quirks2 & SDHCI_QUIRK2_INTERNAL_PWR_CTL))
And this could be:
if (enable_vqmmc)
ret = regulator_enable(mmc->supply.vqmmc);
else
ret = 0;
However, you still need to ensure regulator_disable(mmc->supply.vqmmc) is
only called if regulator_enable() was called.
> + ret = regulator_enable(mmc->supply.vqmmc);
> + else
> + ret = 0;
> if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 1700000,
> 1950000))
> host->caps1 &= ~(SDHCI_SUPPORT_SDR104 |
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 23966f8..3b0c97a 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -450,6 +450,8 @@ struct sdhci_host {
> * obtainable timeout.
> */
> #define SDHCI_QUIRK2_DISABLE_HW_TIMEOUT (1<<17)
> +/* Regulator voltage changes are being done from platform layer */
> +#define SDHCI_QUIRK2_INTERNAL_PWR_CTL (1<<18)
So maybe the quirk is not needed.
>
> int irq; /* Device IRQ */
> void __iomem *ioaddr; /* Mapped address */
>
