[U-Boot] [PATCH V2 1/4] mmc: fsl_esdhc: introduce vs18_enable for 1.8V fix I/O

[Peng Fan]

> -----Original Message-----
> From: Jagan Teki [mailto:jagannadh.teki at gmail.com]
> Sent: Tuesday, May 09, 2017 7:09 PM
> To: Peng Fan <peng.fan at nxp.com>
> Cc: Stefano Babic <sbabic at denx.de>; u-boot at lists.denx.de
> Subject: Re: [U-Boot] [PATCH V2 1/4] mmc: fsl_esdhc: introduce vs18_enable
> for 1.8V fix I/O
> 
> On Mon, May 8, 2017 at 12:32 PM, Peng Fan <peng.fan at nxp.com> wrote:
> > When using eMMC with 1.8V I/O, the VSELECT bit need to be set in the
> > USDHC controller when init.
> >
> > This patch adds a parameter "vs18_enable" in fsl_esdhc_cfg structure
> > and priv data, so each controller can have different settings.
> >
> > We could not use CONFIG_SYS_FSL_ESDHC_FORCE_VSELECT, it has problem
> > that it will apply to all USDHC controllers and it only set the 1.8V
> > at init phase. So if user does not select to the eMMC device, the
> > voltage on the I/O pins are not correct.
> >
> > Signed-off-by: Peng Fan <peng.fan at nxp.com>
> > Cc: Jaehoon Chung <jh80.chung at samsung.com>
> > Cc: York Sun <york.sun at nxp.com>
> > Cc: Stefano Babic <sbabic at denx.de>
> > ---
> >
> > V2: None
> >
> >  drivers/mmc/fsl_esdhc.c | 9 +++++++++
> >  include/fsl_esdhc.h     | 1 +
> >  2 files changed, 10 insertions(+)
> >
> > diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index
> > f3c6358..bddfe24 100644
> > --- a/drivers/mmc/fsl_esdhc.c
> > +++ b/drivers/mmc/fsl_esdhc.c
> > @@ -92,6 +92,7 @@ struct fsl_esdhc {
> >   * @dev: pointer for the device
> >   * @non_removable: 0: removable; 1: non-removable
> >   * @wp_enable: 1: enable checking wp; 0: no check
> > + * @vs18_enable: 1: use 1.8V voltage; 0: use 3.3V
> >   * @cd_gpio: gpio for card detection
> >   * @wp_gpio: gpio for write protection
> >   */
> > @@ -104,6 +105,7 @@ struct fsl_esdhc_priv {
> >         struct udevice *dev;
> >         int non_removable;
> >         int wp_enable;
> > +       int vs18_enable;
> 
> I think this can be achieved with adding "no-1-8-v" property.

We need to support non-dts case.

Regards,
Peng.

> 
> thanks!
> --
> Jagan Teki
> Free Software Engineer | www.openedev.com U-Boot, Linux | Upstream
> Maintainer Hyderabad, India.