On 1/21/21 9:40 PM, Aswath Govindraju wrote:
> From: Faiz Abbas <faiz_ab...@ti.com>
>
> Add a set_voltage() function which handles the switch from 3.3V to 1.8V
> for SD card UHS modes.
>
> Signed-off-by: Faiz Abbas <faiz_ab...@ti.com>
> Signed-off-by: Aswath Govindraju <a-govindr...@ti.com>
> ---
> drivers/mmc/sdhci.c | 80 +++++++++++++++++++++++++++++++++++++++++++++
> include/sdhci.h | 1 +
> 2 files changed, 81 insertions(+)
>
> diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
> index 06289343124e..e7e3e22d1a7e 100644
> --- a/drivers/mmc/sdhci.c
> +++ b/drivers/mmc/sdhci.c
> @@ -20,6 +20,7 @@
> #include <linux/delay.h>
> #include <linux/dma-mapping.h>
> #include <phys2bus.h>
> +#include <power/regulator.h>
>
> static void sdhci_reset(struct sdhci_host *host, u8 mask)
> {
> @@ -509,6 +510,85 @@ void sdhci_set_uhs_timing(struct sdhci_host *host)
> sdhci_writew(host, reg, SDHCI_HOST_CONTROL2);
> }
>
> +#if CONFIG_IS_ENABLED(MMC_IO_VOLTAGE)
> +static void sdhci_set_voltage(struct sdhci_host *host)
> +{
> + struct mmc *mmc = (struct mmc *)host->mmc;
> + u32 ctrl;
> + int ret;
> +
> + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> +
> + switch (mmc->signal_voltage) {
> + case MMC_SIGNAL_VOLTAGE_330:
> +#if CONFIG_IS_ENABLED(DM_REGULATOR)
> + if (mmc->vqmmc_supply) {
> + ret = regulator_set_enable(mmc->vqmmc_supply, false);
> + if (ret) {
> + pr_err("failed to disable vqmmc-supply: %d\n",
> ret);
> + return;
> + }
> +
> + ret = regulator_set_value(mmc->vqmmc_supply, 3300000);
> + if (ret) {
> + pr_err("failed to set vqmmc-voltage to 3.3V:
> %d\n", ret);
> + return;
> + }
> +
> + ret = regulator_set_enable(mmc->vqmmc_supply, true);
> + if (ret) {
> + pr_err("failed to enable vqmmc-supply: %d\n",
> ret);
> + return;
> + }
> + }
> +#endif
> + mdelay(5);
Could you add just comment for mdelay(5)? Maybe it needs to be stable, right?
Best Regards,
Jaehoon Chung
> + if (IS_SD(mmc)) {
> + ctrl &= ~SDHCI_CTRL_VDD_180;
> + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
> + }
> + break;
> + case MMC_SIGNAL_VOLTAGE_180:
> +#if CONFIG_IS_ENABLED(DM_REGULATOR)
> + if (mmc->vqmmc_supply) {
> + regulator_set_enable(mmc->vqmmc_supply, false);
> + if (ret) {
> + pr_err("failed to disable vqmmc-supply: %d\n",
> ret);
> + return;
> + }
> +
> + regulator_set_value(mmc->vqmmc_supply, 1800000);
> + if (ret) {
> + pr_err("failed to set vqmmc-voltage to 1.8V:
> %d\n", ret);
> + return;
> + }
> +
> + regulator_set_enable(mmc->vqmmc_supply, true);
> + if (ret) {
> + pr_err("failed to enable vqmmc-supply: %d\n",
> ret);
> + return;
> + }
> + }
> +#endif
> + if (IS_SD(mmc)) {
> + ctrl |= SDHCI_CTRL_VDD_180;
> + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
> + }
> + break;
> + default:
> + /* No signal voltage switch required */
> + return;
> + }
> +}
> +#else
> +static void sdhci_set_voltage(struct sdhci_host *host) { }
> +#endif
> +void sdhci_set_control_reg(struct sdhci_host *host)
> +{
> + sdhci_set_voltage(host);
> + sdhci_set_uhs_timing(host);
> +}
> +
> #ifdef CONFIG_DM_MMC
> static int sdhci_set_ios(struct udevice *dev)
> {
> diff --git a/include/sdhci.h b/include/sdhci.h
> index 3e5a64981857..0f820c6d2669 100644
> --- a/include/sdhci.h
> +++ b/include/sdhci.h
> @@ -491,6 +491,7 @@ void sdhci_set_uhs_timing(struct sdhci_host *host);
> /* Export the operations to drivers */
> int sdhci_probe(struct udevice *dev);
> int sdhci_set_clock(struct mmc *mmc, unsigned int clock);
> +void sdhci_set_control_reg(struct sdhci_host *host);
> extern const struct dm_mmc_ops sdhci_ops;
> #else
> #endif
>
