Subject: [PATCH 20/23] mmc: sdhci-esdhc-imx: fix strobe DLL lock wrong clock issue

From: [email-masked] (Dong Aisheng)
Date: Thu, 26 May 2016 19:47:48 +0800

On Tue, May 10, 2016 at 03:03:48PM +0300, Adrian Hunter wrote:
> On 15/04/16 20:29, Dong Aisheng wrote:
> > When enable DDR, the clock factor definition is changed.
> > e.g. original 200Mhz will become 100Mhz one MIX_CTRL_DDREN bit is set
> > So we need to update the clock setting then the strobe dll can lock
> > the correct clock rate.
> > 
> > Additionally we also need disable the clock before locking strobe dll.
> > 
> > Signed-off-by: Dong Aisheng <[email-masked]>
> 
> Apart from redundant parentheses (refer below):
> 
> Acked-by: Adrian Hunter <[email-masked]>
> 

Could remove in V2.
Thanks for the suggestion.

Regards
Dong Aisheng

> > ---
> >  drivers/mmc/host/sdhci-esdhc-imx.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> > 
> > diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> > index 07b1144..3ff213f 100644
> > --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> > +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> > @@ -852,6 +852,11 @@ static void esdhc_set_strobe_dll(struct sdhci_host *host)
> >  	u32 v;
> >  
> >  	if (host->mmc->actual_clock > ESDHC_STROBE_DLL_CLK_FREQ) {
> > +		/* disable clock before enabling strobe dll */
> > +		writel(readl(host->ioaddr + ESDHC_VENDOR_SPEC) &
> > +		       (~ESDHC_VENDOR_SPEC_FRC_SDCLK_ON),
> 
> Parentheses look redundant
> 
> > +		       host->ioaddr + ESDHC_VENDOR_SPEC);
> > +
> >  		/* force a reset on strobe dll */
> >  		writel(ESDHC_STROBE_DLL_CTRL_RESET,
> >  			host->ioaddr + ESDHC_STROBE_DLL_CTRL);
> > @@ -913,6 +918,8 @@ static void esdhc_set_uhs_signaling(struct sdhci_host *host, unsigned timing)
> >  		m |= ESDHC_MIX_CTRL_DDREN | ESDHC_MIX_CTRL_HS400_EN;
> >  		writel(m, host->ioaddr + ESDHC_MIX_CTRL);
> >  		imx_data->is_ddr = 1;
> > +		/* update clock after enable DDR for strobe DLL lock */
> > +		host->ops->set_clock(host, host->clock);
> >  		esdhc_set_strobe_dll(host);
> >  		break;
> >  	}
> > 
>