From mboxrd@z Thu Jan 1 00:00:00 1970 From: adrian.hunter@intel.com (Adrian Hunter) Date: Tue, 14 Jun 2016 10:07:06 +0300 Subject: [PATCH 05/12] mmc: sdhci: add a pre voltage switch callback function In-Reply-To: References: <1465456218-28354-1-git-send-email-gregory.clement@free-electrons.com> <1465456218-28354-6-git-send-email-gregory.clement@free-electrons.com> <575E72DC.5090604@intel.com> Message-ID: <575FAD1A.6090407@intel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 13/06/16 17:04, Ziji Hu wrote: > Hi Adrian, > > Thanks a lot for the suggestion. I'm from Marvell Xenon SDHC team. Most > of sdhci host ops are still used in our driver. We just change or add few > ops. Thus, if we create our own mmc_host_ops, many static sdhci host ops > will be exported. I would like to know whether such a modification can be > accepted or not. > > I notice that community is improving sdhci. Thus all the static sdhci ops > called outside the sdhci.c will be exported. Is my understanding > correct? Thank you. The aim is to make sdhci more like a library and give more control to the drivers. That will mean more sdhci functions get exported, particularly mmc host ops like sdhci_set_ios() or sdhci_start_signal_voltage_switch(). > > Best regards, Hu Ziji > >>> ? 2016?6?13??16:52?Adrian Hunter ??? >>> >>> On 09/06/16 10:10, Gregory CLEMENT wrote: From: Victor Gu >>> >>> >>> 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); } >> >> >>> >>> [gregory.clement at free-electrons.com: split the initial commit and >>> reformulate the log] >>> >>> Signed-off-by: Victor Gu Signed-off-by: Marcin >>> Wojtas Signed-off-by: Gregory CLEMENT >>> --- 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 >> >> -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" >> in the body of a message to majordomo at vger.kernel.org More majordomo >> info at http://vger.kernel.org/majordomo-info.html