From: Victor Gu <xigu@xxxxxxxxxxx> Some host controller such as Xenon needs additional setting when switching signal voltage in eMMC mode. They also need to re-enable internal clock before a voltage switch. This commit adds a callback routine "voltage_switch_pre" in the struct sdhci_ops, which is used by some host controllers which need re-enable the internal clock before a voltage switch. [gregory.clement@xxxxxxxxxxxxxxxxxx: split the initial commit and reformulate the log] Signed-off-by: Victor Gu <xigu@xxxxxxxxxxx> Signed-off-by: Marcin Wojtas <mw@xxxxxxxxxxxx> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx> --- drivers/mmc/host/sdhci.c | 4 ++++ drivers/mmc/host/sdhci.h | 1 + 2 files changed, 5 insertions(+) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index b07219426d39..cad03ffa9d9b 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1729,6 +1729,10 @@ static int sdhci_start_signal_voltage_switch(struct mmc_host *mmc, if (host->version < SDHCI_SPEC_300) return 0; + /* Some controller need to do more before switching */ + if (host->ops->voltage_switch_pre) + host->ops->voltage_switch_pre(host); + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); switch (ios->signal_voltage) { diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index 49c6c5b0e33b..6bec1b0368d2 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -550,6 +550,7 @@ struct sdhci_ops { unsigned int max_dtr, int host_drv, int card_drv, int *drv_type); void (*init_card)(struct sdhci_host *host, struct mmc_card *card); + void (*voltage_switch_pre)(struct sdhci_host *host); }; #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html