[U-Boot] [v2, 1/3] mmc: fsl_esdhc: add esdhc_imx flag

[Y.b. Lu]

Hi Lukasz,

> -----Original Message-----
> From: Lukasz Majewski <lukma at denx.de>
> Sent: Monday, February 18, 2019 7:12 AM
> To: Y.b. Lu <yangbo.lu at nxp.com>
> Cc: u-boot at lists.denx.de
> Subject: Re: [U-Boot] [v2, 1/3] mmc: fsl_esdhc: add esdhc_imx flag
> 
> Dear "Y.b. Lu",
> 
> > The fsl_esdhc driver was for Freescale eSDHC on MPC83XX/MPC85XX
> > initially. The later QoriQ series processors (which were evolutions of
> > MPC83XX/MPC85XX) and i.MX series processors were using this driver for
> > their eSDHCs too.
> >
> > So there are two evolution directions for eSDHC now. For the two
> > series processors, the eSDHCs are becoming more and more different.
> > We should have split it into two drivers, like them
> > (sdhci-of-esdhc.c/sdhci-esdhc-imx.c) in linux kernel.
> 
> Why we cannot do it right just from the very beginning?
> 
> In the end of the day we will try to mimic Linux kernel anyway, IMHO it is
> better to start the split now and save some effort on a half-step solution.
> 

[Y.b. Lu] I understand. The perfect way is to split them.
However, if you grep 'CONFIG_FSL_ESDHC' in the whole u-boot source, you would find there are 607 results.
There will be so many companies boards affected. I just don't know who could make all of these boards tested.

My current patch-set is also to cleaning up the driver waiting for splitting them someday on the other hand.
After you check CONFIG_FSL_ESDHC in u-boot source, if you think it's better we should split them right now, I could work on the driver splitting.

Thanks a lot.

> > But it seemed
> > to be a lot of work now. So let's keep as it is. Be very careful to
> > change the driver if the changes are not common for all eSDHCs, and
> > clarify i.MX eSDHC specific things to distingush them with QorIQ
> > eSDHC.
> >
> > This patch is to added an esdhc_imx flag for the development of i.MX
> > eSDHC, to distinguish it with QoriQ eSDHC.
> >
> > Signed-off-by: Yangbo Lu <yangbo.lu at nxp.com>
> > ---
> > Changes for v2:
> > 	- Converted to use device_is_compatible().
> > ---
> >  drivers/mmc/fsl_esdhc.c | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index
> > 21fa2ab1d4..a647bc7f1c 100644
> > --- a/drivers/mmc/fsl_esdhc.c
> > +++ b/drivers/mmc/fsl_esdhc.c
> > @@ -147,6 +147,7 @@ struct fsl_esdhc_priv {
> >  	struct gpio_desc cd_gpio;
> >  	struct gpio_desc wp_gpio;
> >  #endif
> > +	bool esdhc_imx;
> >  };
> >
> >  /* Return the XFERTYP flags for a given command and data packet */ @@
> > -1462,6 +1463,16 @@ static int fsl_esdhc_probe(struct udevice *dev)
> >  		priv->caps = data->caps;
> >  	}
> >
> > +	/*
> > +	 * This is to specify whether current eSDHC is an i.MX eSDHC,
> > +	 * since the i.MX eSDHC has been becoming more and more
> > different
> > +	 * with QorIQ eSDHC and initial MPC83XX/MPC85XX.
> > +	 */
> > +	if (!device_is_compatible(dev, "fsl,esdhc"))
> > +		priv->esdhc_imx = true;
> > +	else
> > +		priv->esdhc_imx = false;
> > +
> >  	val = dev_read_u32_default(dev, "bus-width", -1);
> >  	if (val == 8)
> >  		priv->bus_width = 8;
> 
> 
> 
> 
> Best regards,
> 
> Lukasz Majewski
> 
> --
> 
> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
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