On 6/09/24 20:50, Judith Mendez wrote:
> The sdhci_start_signal_voltage_switch function sets
> V1P8_SIGNAL_ENA by default after switching to 1v8 signaling.
> V1P8_SIGNAL_ENA determines whether to launch cmd/data on neg
> edge or pos edge of clock.
>
> Due to some eMMC and SD failures seen across am62x platform,
> do not set V1P8_SIGNAL_ENA by default, only enable the bit
> for devices that require this bit in order to switch to 1v8
> voltage for uhs modes.
>
> Signed-off-by: Judith Mendez <jm@xxxxxx>
> ---
> drivers/mmc/host/sdhci_am654.c | 86 ++++++++++++++++++++++++++++++++++
> 1 file changed, 86 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
> index 0aa3c40ea6ed8..fb6232e56606b 100644
> --- a/drivers/mmc/host/sdhci_am654.c
> +++ b/drivers/mmc/host/sdhci_am654.c
> @@ -155,6 +155,7 @@ struct sdhci_am654_data {
> u32 tuning_loop;
>
> #define SDHCI_AM654_QUIRK_FORCE_CDTEST BIT(0)
> +#define SDHCI_AM654_QUIRK_SET_V1P8_ENA BIT(1)
It would be better for the quirk to represent the deviation
from normal i.e.
#define SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA BIT(1)
> };
>
> struct window {
> @@ -356,6 +357,79 @@ static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host,
> sdhci_set_clock(host, clock);
> }
>
> +int sdhci_am654_start_signal_voltage_switch(struct mmc_host *mmc,
> + struct mmc_ios *ios)
Simpler to call sdhci_start_signal_voltage_switch() for the normal
case e.g.
static int sdhci_am654_start_signal_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct sdhci_host *host = mmc_priv(mmc);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
if ((sdhci_am654->quirks & SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA) &&
ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
ret = mmc_regulator_set_vqmmc(mmc, ios);
if (ret < 0) {
pr_warn("%s: Switching to 1.8V signalling voltage failed\n",
mmc_hostname(mmc));
return -EIO;
}
return 0;
}
return sdhci_start_signal_voltage_switch(mmc, ios);
}
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
> + u16 ctrl;
> + int ret;
> +
> + if (host->version < SDHCI_SPEC_300)
> + return 0;
> +
> + switch (ios->signal_voltage) {
> + case MMC_SIGNAL_VOLTAGE_330:
> + if (!(host->flags & SDHCI_SIGNALING_330))
> + return -EINVAL;
> +
> + ctrl &= ~SDHCI_CTRL_VDD_180;
> + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
> +
> + if (!IS_ERR(mmc->supply.vqmmc)) {
> + ret = mmc_regulator_set_vqmmc(mmc, ios);
> + if (ret < 0) {
> + pr_warn("%s: Switching to 3.3V signalling voltage failed\n",
> + mmc_hostname(mmc));
> + return -EIO;
> + }
> + }
> +
> + usleep_range(5000, 5500);
> +
> + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> + if (!(ctrl & SDHCI_CTRL_VDD_180))
> + return 0;
> +
> + pr_warn("%s: 3.3V regulator output did not become stable\n",
> + mmc_hostname(mmc));
> +
> + return -EAGAIN;
> +
> + case MMC_SIGNAL_VOLTAGE_180:
> + if (!(host->flags & SDHCI_SIGNALING_180))
> + return -EINVAL;
> +
> + if (!IS_ERR(mmc->supply.vqmmc)) {
> + ret = mmc_regulator_set_vqmmc(mmc, ios);
> + if (ret < 0) {
> + pr_warn("%s: Switching to 1.8V signalling voltage failed\n",
> + mmc_hostname(mmc));
> + return -EIO;
> + }
> + }
> +
> + if (sdhci_am654->quirks & SDHCI_AM654_QUIRK_SET_V1P8_ENA) {
> + ctrl |= SDHCI_CTRL_VDD_180;
> + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
> +
> + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> + if (ctrl & SDHCI_CTRL_VDD_180)
> + return 0;
> +
> + pr_warn("%s: 1.8V regulator output did not become stable\n",
> + mmc_hostname(mmc));
> +
> + return -EAGAIN;
> + }
> + return 0;
> +
> + default:
> + return 0;
> + }
> +}
> +
> static u8 sdhci_am654_write_power_on(struct sdhci_host *host, u8 val, int reg)
> {
> writeb(val, host->ioaddr + reg);
> @@ -801,6 +875,8 @@ static int sdhci_am654_get_of_property(struct platform_device *pdev,
> struct sdhci_am654_data *sdhci_am654)
> {
> struct device *dev = &pdev->dev;
> + struct device_node *np = dev->of_node;
> + struct device_node *node;
> int drv_strength;
> int ret;
>
> @@ -844,6 +920,15 @@ static int sdhci_am654_get_of_property(struct platform_device *pdev,
> if (device_property_read_bool(dev, "ti,fails-without-test-cd"))
> sdhci_am654->quirks |= SDHCI_AM654_QUIRK_FORCE_CDTEST;
>
> + node = of_parse_phandle(np, "vmmc-supply", 0);
> +
> + if (node) {
> + node = of_parse_phandle(np, "vqmmc-supply", 0);
> +
> + if (!node)
> + sdhci_am654->quirks |= SDHCI_AM654_QUIRK_SET_V1P8_ENA;
> + }
It would be simpler without 'np' and 'node'. Not sure
what the rule is meant to be, but it could be something like:
if (of_parse_phandle(dev->of_node, "vmmc-supply", 0) &&
of_parse_phandle(dev->of_node, "vqmmc-supply", 0)
sdhci_am654->quirks |= SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA;
> +
> sdhci_get_of_property(pdev);
>
> return 0;
> @@ -940,6 +1025,7 @@ static int sdhci_am654_probe(struct platform_device *pdev)
> goto err_pltfm_free;
> }
>
> + host->mmc_host_ops.start_signal_voltage_switch = sdhci_am654_start_signal_voltage_switch;
> host->mmc_host_ops.execute_tuning = sdhci_am654_execute_tuning;
>
> pm_runtime_get_noresume(dev);
>
> base-commit: cf6444ba528f043398b112ac36e041a4d8685cb1
