Re: [PATCH 1/2] Support SD UHS for hikey-mainline-rebase

[Shawn Lin]

å 2016/7/19 20:28, Jinguojun åé:
> On 2016/7/19 16:13, Jaehoon Chung wrote:
> > Hi,
> >
> > Removed the unnecessary CC'd.
> >
> > On 07/19/2016 04:51 PM, Jin Guojun wrote:
> > > From: j00226943 <j00226943@xxxxxxxxxxxxxxxxxxxx>
> >
> > What is j00226943?
> >
> > When you send the patch for dw_mmc controller, plz use the prefix "mmc: dw_mmc: ".
> >
> > > Two more changes:
> > >
> > > Before we send cmd,we need to set CMD bit29 to
> > > 1 so that CMD and DATA sent to card through the HOLD Register,
> > > This is the explication in synosys host:To meet the relatively
> > > high Input Hold Time requirement for SDR12, SDR25, and other MMC
> > > speed modes, you should program bit[29]use_hold_Reg of the CMD
> > > register to 1'b1; the output data is then registered again in the
> > > cclk_in_drv domain by using the Hold Register as shown in Path B
> > > of Figure 10-8. However, for the higher speed modes of SDR104, SDR50
> > > and DDR50, you can meet the much smaller Input Hold Time requirement
> > > of 0.8ns by bypassing the Hold Register (Path A in Figure 10-8,
> > > programming CMD.use_hold_reg = 1'b0) and then adding delay elements
> > > on the output path as indicated
> > >
> > > We have no tuning function in our drivers,so we must do the
> > > Function piling when we init UHS card.
>
> 1.For hikey we cant support UHS for SD card in https://github.com/96boards-hikey/linux/tree/hikey-mainline-rebase
> 2.I have no SDMMC_CMD_USE_HOLD_REG in Dw_mmc-k3.c
>
> > Sorry..this patch is NACK.
> > SDMMC_CMD_USE_HOLD_REG is already used by default in dw_mmc.c
> > Which kernel version did you use?
> >
> > > Signed-off-by: Jin Guojun <kid.jin@xxxxxxxxxxxxx>
> > > ---
> > >  drivers/mmc/host/dw_mmc-k3.c | 6 ++++++
> > >  drivers/mmc/host/dw_mmc.c    | 2 ++
> > >  2 files changed, 8 insertions(+)
> > >
> > > diff --git a/drivers/mmc/host/dw_mmc-k3.c b/drivers/mmc/host/dw_mmc-k3.c
> > > index 63c2e2e..2cbfcc7 100644
> > > --- a/drivers/mmc/host/dw_mmc-k3.c
> > > +++ b/drivers/mmc/host/dw_mmc-k3.c
> > > @@ -125,10 +125,16 @@ static void dw_mci_hi6220_set_ios(struct dw_mci *host, struct mmc_ios *ios)
> > >  	host->bus_hz = clk_get_rate(host->biu_clk);
> > >  }
> > >
> > > +static void dw_mci_hi6220_prepare_command(struct dw_mci *host, u32 *cmdr)
> > > +{
> > > +	*cmdr |= SDMMC_CMD_USE_HOLD_REG;
> > > +}
> > > +
> > >  static const struct dw_mci_drv_data hi6220_data = {
> > >  	.switch_voltage		= dw_mci_hi6220_switch_voltage,
> > >  	.set_ios		= dw_mci_hi6220_set_ios,
> > >  	.parse_dt		= dw_mci_hi6220_parse_dt,
> > > +	.prepare_command        = dw_mci_hi6220_prepare_command,
> > >  };
> Hi,thank you for your review
>
> 1.We do the prepare_command in dw_mci_prepare_command before we send CMD in dw_mmc.c

please clone Ulf's tree[0] and rebase your any patches on its next
branch, thanks.


[0] git://git.linaro.org/people/ulf.hansson/mmc

> 2.I can find the same drivers in dw_mmc-exynos.c
> 3.For hikey we do the initialization from Dw_mmc-k3.c,so I need to do the prepare_command in hi6220 drivers
>
> > There is no "prepare_command" hooks.
> >
> > Best Regards,
> > Jaehoon Chung
> >
> > >  static const struct of_device_id dw_mci_k3_match[] = {
> > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> > > index 9dd1bd3..047e116 100644
> > > --- a/drivers/mmc/host/dw_mmc.c
> > > +++ b/drivers/mmc/host/dw_mmc.c
> > > @@ -1564,6 +1564,8 @@ static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> > >
> > >  	if (drv_data && drv_data->execute_tuning)
> > >  		err = drv_data->execute_tuning(slot, opcode);
> > > +	else
> > > +		err = 0;
> > >  	return err;
> > >  }
> >
> >
> > .


--
Best Regards
Shawn Lin