Re: IMX27: How to do 22k pull-up with the pinctrl ?

[Markus Pargmann <mpa-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>]

On Mon, Nov 11, 2013 at 10:26:41PM +0800, Shawn Guo wrote:
> Copy Markus who is working on imx27 pinctrl driver.
> 
> On Mon, Nov 11, 2013 at 12:03:57PM +0000, Mark Rutland wrote:
> > On Mon, Nov 11, 2013 at 10:45:30AM +0000, Chris Ruehl wrote:
> > > Hi,
> > 
> > Hi,
> > 
> > While this does involve device tree, it's not strictly a device tree
> > problem, and the people best placed to answer your question don't seem
> > to be on Cc. You'd get better responses if you used get_maintainer.pl,
> > or looked at the commit history of the driver or binding to find people
> > likely to be able to help.
> > 
> > I've added Dong Aisheng, Shawn Guo, and Linus Walleij to Cc, as they had
> > signed-off-bys on the binding document.
> 
> Thanks, Mark.
> 
> <snip>
> 
> > > while I port the static code to the DT I step into the problem to
> > > set the PSCR for the sdhc2 ports to 22k pull-up
> 
> Is the code from mainline kernel or private tree?  I'm asking because I
> do not see non-DT imx27 iomux-v1 driver has interface for setting up
> DSCR or PSCR in SYSCTRL block.  That's probably why Markus did not
> support that in the imx27 pinctrl driver, I guess.

DSCR controls groups of pins, for example DS_SLOW10 (DSCR1) controls all
pins of SDHC1 and CSPI3. I don't think a config option for a pin should
influence the behaviour of other pins.
PSCR could be managed by the imx27 pinctrl driver but it is not included
in the GPIO/pinmux module. It is included in "System control module"
which does not exist on imx21 for example.

Regards,

Markus Pargmann

> 
> Shawn
> 
> > > I look for something like described in
> > >      pinctrl/fsl,imx-pinctrl.txt
> > > 
> > > the fsl,imx27-pinctrl only say 0/1 dis/enable pull up but not the strength.
> > > 
> > > 
> > > pinctrl_sdhc2_1: sdhc2-1 {
> > >                          fsl,pins = <
> > >                                  MX27_PAD_SD2_D0__SD2_D0  0x1
> > >                                  MX27_PAD_SD2_D1__SD2_D1  0x1
> > >                                  MX27_PAD_SD2_D2__SD2_D2  0x1
> > >                                  MX27_PAD_SD2_D3__SD2_D3  0x1
> > >                                  MX27_PAD_SD2_CLK__SD2_CLK  0x1
> > >                                  MX27_PAD_SD2_CMD__SD2_CMD  0x1
> > >                          >;
> > >                  };
> > > 
> > > its setup in board specific c-file
> > > 
> > > /* 22k pull-up for sd2 pins  */
> > >          reg = __raw_readw(MX27_IO_ADDRESS(MX27_SYSCTRL_BASE_ADDR + MX27_SYS_PSCR));
> > >          reg &= ~0xfff0;
> > >          reg |= 0xfff0;
> > >          __raw_writew(reg, MX27_IO_ADDRESS(MX27_SYSCTRL_BASE_ADDR + MX27_SYS_PSCR));
> > > 
> > > 
> > > Any successions?
> > > 
> > > Regards
> > > Chris
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe devicetree" in
> > > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > > 
> 
> 

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html