[U-Boot] [PATCH 1/2] mmc: sunxi: Support the new mode

[Maxime Ripard]

On Wed, Jul 12, 2017 at 07:27:12PM +0300, Siarhei Siamashka wrote:
> On Wed, 12 Jul 2017 16:48:37 +0200
> Maxime Ripard <maxime.ripard at free-electrons.com> wrote:
> 
> > Almost all of the newer Allwinner SoCs have a new operating mode for the
> > eMMC clocks that needs to be enabled in both the clock and the MMC
> > controller.
> 
> Can we have a bit better description in the commit message about what
> is new about this mode? Does it bring us some visible improvements
> for the end users? Why do we need to enable it?

I wish I could detail what exactly changes between the old and new
mode, but I have no idea. It seems to be different enough that it
makes eMMC works on the A83T. We also had some commands that were
failing in SDIO on the A64 if not switched to the new mode. But that's
just empirical.

> > 
> > Add support for it through a Kconfig option
> > 
> > Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
> > ---
> >  arch/arm/include/asm/arch-sunxi/mmc.h |  9 ++++++---
> >  drivers/mmc/Kconfig                   |  3 +++
> >  drivers/mmc/sunxi_mmc.c               | 26 +++++++++++++++++++++++---
> >  3 files changed, 32 insertions(+), 6 deletions(-)
> > 
> > diff --git a/arch/arm/include/asm/arch-sunxi/mmc.h b/arch/arm/include/asm/arch-sunxi/mmc.h
> > index cb52e648731c..0c2d496295ff 100644
> > --- a/arch/arm/include/asm/arch-sunxi/mmc.h
> > +++ b/arch/arm/include/asm/arch-sunxi/mmc.h
> > @@ -35,16 +35,19 @@ struct sunxi_mmc {
> >  	u32 cbcr;		/* 0x48 CIU byte count */
> >  	u32 bbcr;		/* 0x4c BIU byte count */
> >  	u32 dbgc;		/* 0x50 debug enable */
> > -	u32 res0[11];
> > +	u32 res0;		/* 0x54 reserved */
> > +	u32 a12a;		/* 0x58 Auto command 12 argument */
> > +	u32 ntsr;		/* 0x5c	New timing set register */
> > +	u32 res1[8];
> >  	u32 dmac;		/* 0x80 internal DMA control */
> >  	u32 dlba;		/* 0x84 internal DMA descr list base address */
> >  	u32 idst;		/* 0x88 internal DMA status */
> >  	u32 idie;		/* 0x8c internal DMA interrupt enable */
> >  	u32 chda;		/* 0x90 */
> >  	u32 cbda;		/* 0x94 */
> > -	u32 res1[26];
> > +	u32 res2[26];
> >  #ifdef CONFIG_SUNXI_GEN_SUN6I
> > -	u32 res2[64];
> > +	u32 res3[64];
> >  #endif
> >  	u32 fifo;		/* 0x100 / 0x200 FIFO access address */
> >  };
> > diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
> > index 82b8d756867c..203f59547100 100644
> > --- a/drivers/mmc/Kconfig
> > +++ b/drivers/mmc/Kconfig
> > @@ -368,6 +368,9 @@ config MMC_SUNXI
> >  	  This selects support for the SD/MMC Host Controller on
> >  	  Allwinner sunxi SoCs.
> >  
> > +config MMC_SUNXI_HAS_NEW_MODE
> > +	bool
> > +
> >  config GENERIC_ATMEL_MCI
> >  	bool "Atmel Multimedia Card Interface support"
> >  	depends on DM_MMC && BLK && DM_MMC_OPS && ARCH_AT91
> > diff --git a/drivers/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c
> > index fd3fc2af40a0..68750f3832b6 100644
> > --- a/drivers/mmc/sunxi_mmc.c
> > +++ b/drivers/mmc/sunxi_mmc.c
> > @@ -87,6 +87,20 @@ static int mmc_resource_init(int sdc_no)
> >  static int mmc_set_mod_clk(struct sunxi_mmc_host *mmchost, unsigned int hz)
> >  {
> >  	unsigned int pll, pll_hz, div, n, oclk_dly, sclk_dly;
> > +	bool new_mode = false;
> > +	u32 val = 0;
> > +
> > +#ifdef CONFIG_MMC_SUNXI_HAS_NEW_MODE
> > +	if (mmchost->mmc_no == 2)
> > +		new_mode = true;
> > +#endif
> 
> Please change this ifdef to use:
> 
>     if (IS_ENABLED(CONFIG_MMC_SUNXI_HAS_NEW_MODE))

Ok.

> > +
> > +	/*
> > +	 * The MMC clock has an extra /2 post-divider when operating in the new
> > +	 * mode.
> > +	 */
> > +	if (new_mode)
> > +		hz = hz * 2;
> >  
> >  	if (hz <= 24000000) {
> >  		pll = CCM_MMC_CTRL_OSCM24;
> > @@ -143,9 +157,15 @@ static int mmc_set_mod_clk(struct sunxi_mmc_host *mmchost, unsigned int hz)
> >  #endif
> >  	}
> >  
> > -	writel(CCM_MMC_CTRL_ENABLE | pll | CCM_MMC_CTRL_SCLK_DLY(sclk_dly) |
> > -	       CCM_MMC_CTRL_N(n) | CCM_MMC_CTRL_OCLK_DLY(oclk_dly) |
> > -	       CCM_MMC_CTRL_M(div), mmchost->mclkreg);
> > +	if (new_mode) {
> > +		val = BIT(30);
> 
> Does this BIT(30) have a name?
> 
> > +		writel(BIT(31), &mmchost->reg->ntsr);
> 
> The same question here.

I'll add defines. Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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