Hi Adrian, On lun., juin 13 2016, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote: > On 09/06/16 10:10, Gregory CLEMENT wrote: >> 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. > > Don't want to add sdhci host ops for the "do something before a mmc host op" > case. > > Instead, export sdhci_start_signal_voltage_switch() and hook > host->mmc_host_ops.start_signal_voltage_switch. Then in sdhci-xenon.c: > > int xenon__start_signal_voltage_switch(struct mmc_host *mmc, > struct mmc_ios *ios) > { > blah blah > return sdhci_start_signal_voltage_switch(mmc, ios); > } OK I see your point. Thanks, Gregory > > >> >> [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 >> > -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html