[PATCH 05/12] mmc: sdhci: add a pre voltage switch callback function

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

quoted

quoted

? 2016?6?13??16:52?Adrian Hunter [off-list ref] ???

On 09/06/16 10:10, Gregory CLEMENT wrote: From: Victor Gu
[off-list ref]

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); }

quoted

[gregory.clement at free-electrons.com: split the initial commit and 
reformulate the log]

Signed-off-by: Victor Gu <redacted> Signed-off-by: Marcin
Wojtas [off-list ref] Signed-off-by: Gregory CLEMENT
[off-list ref] --- 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