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

[Chris Ruehl <chris.ruehl-CR359r9tUDPXPF5Rlphj1Q@public.gmane.org>]

On Tuesday, November 12, 2013 12:21 AM, Markus Pargmann wrote:
> 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

Hi Markus,

do you think its difficult to add the mentioned PSCR manipulations to a
new to add System control module?

Regards
Chris

>
>>
>> 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

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