Re: [PATCH 1/3] sunxi: mmc: ignore card detect in SPL

[Andre Przywara <andre.przywara@arm.com>]

On Sun, 8 Jan 2023 15:00:29 -0600
Samuel Holland <samuel@sholland.org> wrote:

Hi Samuel,

> Thanks for helping to get rid of sunxi_name_to_gpio().

many thanks for the review, that's much appreciated.

> 
> On 7/13/22 11:21, Andre Przywara wrote:
> > The sunxi MMC code does not use the DM in the SPL, as we don't have a
> > device tree available that early, also no space for it.
> > This also means we cannot access the card-detect GPIO information from
> > there, so we have Kconfig symbols called CONFIG_MMCx_CD_PIN, which each
> > board has to define. This is a burden, also requires extra GPIO code in
> > the SPL.
> > As the SPL is the natural successor of the BootROM (from which we are
> > loaded), we can actually ignore the CD pin completely, as this is what
> > the BootROM does as well: CD GPIOs are board specific, but the BootROM
> > is not, so accesses the MMC devices anyway.  
> 
> The card detection logic is useless for an even simpler reason: because
> of our spl_boot_device() implementation, SPL only accesses the MMC
> interface where SPL itself was originally read from. Therefore, it must
> have a card inserted.

Indeed, I thought I mentioned this as well, but didn't. I added a
sentence to that effect to the commit message (and removed the
underscore in the comment below).

Cheers,
Andre


> 
> > Remove the card detect code from the non-DM implementation of the sunxi
> > MMC driver, to get rid of this unneeded code.
> > 
> > Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> > ---
> >  drivers/mmc/sunxi_mmc.c | 37 ++-----------------------------------
> >  1 file changed, 2 insertions(+), 35 deletions(-)
> > 
> > diff --git a/drivers/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c
> > index 1bb7b6d0e9..b2f7e2d142 100644
> > --- a/drivers/mmc/sunxi_mmc.c
> > +++ b/drivers/mmc/sunxi_mmc.c
> > @@ -44,22 +44,10 @@ struct sunxi_mmc_priv {
> >  /* support 4 mmc hosts */
> >  struct sunxi_mmc_priv mmc_host[4];
> >  
> > -static int sunxi_mmc_getcd_gpio(int sdc_no)
> > -{
> > -	switch (sdc_no) {
> > -	case 0: return sunxi_name_to_gpio(CONFIG_MMC0_CD_PIN);
> > -	case 1: return sunxi_name_to_gpio(CONFIG_MMC1_CD_PIN);
> > -	case 2: return sunxi_name_to_gpio(CONFIG_MMC2_CD_PIN);
> > -	case 3: return sunxi_name_to_gpio(CONFIG_MMC3_CD_PIN);
> > -	}
> > -	return -EINVAL;
> > -}
> > -
> >  static int mmc_resource_init(int sdc_no)
> >  {
> >  	struct sunxi_mmc_priv *priv = &mmc_host[sdc_no];
> >  	struct sunxi_ccm_reg *ccm = (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
> > -	int cd_pin, ret = 0;
> >  
> >  	debug("init mmc %d resource\n", sdc_no);
> >  
> > @@ -90,16 +78,7 @@ static int mmc_resource_init(int sdc_no)
> >  	}
> >  	priv->mmc_no = sdc_no;
> >  
> > -	cd_pin = sunxi_mmc_getcd_gpio(sdc_no);
> > -	if (cd_pin >= 0) {
> > -		ret = gpio_request(cd_pin, "mmc_cd");
> > -		if (!ret) {
> > -			sunxi_gpio_set_pull(cd_pin, SUNXI_GPIO_PULL_UP);
> > -			ret = gpio_direction_input(cd_pin);
> > -		}
> > -	}
> > -
> > -	return ret;
> > +	return 0;
> >  }
> >  #endif
> >  
> > @@ -523,23 +502,11 @@ static int sunxi_mmc_send_cmd_legacy(struct mmc *mmc, struct mmc_cmd *cmd,
> >  	return sunxi_mmc_send_cmd_common(priv, mmc, cmd, data);
> >  }
> >  
> > -static int sunxi_mmc_getcd_legacy(struct mmc *mmc)
> > -{
> > -	struct sunxi_mmc_priv *priv = mmc->priv;
> > -	int cd_pin;
> > -
> > -	cd_pin = sunxi_mmc_getcd_gpio(priv->mmc_no);
> > -	if (cd_pin < 0)
> > -		return 1;
> > -
> > -	return !gpio_get_value(cd_pin);
> > -}
> > -
> > +/* .get_cd is not needed by the SPL */  
> 
> nit: s/get_cd/getcd/
> 
> Reviewed-by: Samuel Holland <samuel@sholland.org>
> Tested-by: Samuel Holland <samuel@sholland.org>
> 
> >  static const struct mmc_ops sunxi_mmc_ops = {
> >  	.send_cmd	= sunxi_mmc_send_cmd_legacy,
> >  	.set_ios	= sunxi_mmc_set_ios_legacy,
> >  	.init		= sunxi_mmc_core_init,
> > -	.getcd		= sunxi_mmc_getcd_legacy,
> >  };
> >  
> >  struct mmc *sunxi_mmc_init(int sdc_no)  
> 
>