lkml.org 
[lkml]   [2012]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 2/4] pinctrl: pinctrl-imx: add imx pinctrl core driver
On Thu, Apr 26, 2012 at 10:40:25PM +0800, Dong Aisheng wrote:
> From: Dong Aisheng <dong.aisheng@linaro.org>
>
> The driver has mux and config support while the gpio is still
> not supported.
> For select input setting, the driver will handle it internally
> and do not need user to take care of it.
>
> The pinctrl-imx core driver will parse the dts file and dynamically
> create the pinmux functions and groups.
>
> Each IMX SoC pinctrl driver should register pins with a pin register map
> including mux register and config register and select input map to core
> for proper operations.
>
> Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
>
> ---
> ChangeLog: v2->v3:
> * add missed SION bit set from device tree
> Thanks for Richard Zhao's reminder.
> ChangeLog: v1->v2:
> * Change the binding a bit.
> For fsl,pins property, change it from pin name strings to pin function id
> which represents a pin working on a specific function. Then we can remove
> fsl,mux property since the pin function id already contains the mux setting.
> Also remove other pin config property in the first patch.
> Because in the future, we will switch to use dtc macro, then using a lot of
> propertys to represent the each pin config like pull, speed and etc seems
> needless.
> Then each pin entry in dts file becomes a pair of PIN_FUNC_ID and CONFIG:
> fsl,pins = <PIN_FUNC_ID CONFIG ..>
> See binding doc for details.
> * Sascha raised a question that pins in the same group may have different
> pad setting for example I2C_CLK needs pull up while I2C_DAT not.
> The v1 driver can aslo handle this issue but needs split the different
> pad setting pins into different groups which loses a bit flexibility.
> Also suggested by Richard Zhao and Jason Liu, we may still want the iomux
> v3 simililar using way that allows each pin has the abiblity to configure
> its pad which seems reasonable because from HW point of view, FSL IMX are
> indeed pin based SoC which should be able to set per pin.
> So the main changes in this v2 patch are change to support per pin config.
> Then the using of iomux is almost the same as the existing iomux v3 for
> non dt imx platforms. See binding doc for example.
>
> After introduce the new way, there're mainly two known issues:
> 1) Since many pins in the same group may have the same pad config setting,
> thus there may be some data redundance, however, since it's one word
> and it's purely describe hw i would think it's not a big issue.
> 2) Need a magic number to indicate no pad config need. In current iomux v3,
> It's 1<<16 which is not used by IMX5, i used 1<<31 for both MX5 and MX6.
> However, it's definitely possibile that in the future, the bit 31 may also
> be used, that means we may need change the binding doc or just handle it in
> driver for different SoCs.
> 3) Due to core limitation, the current pinconf_group_set/get only support
> get/set the same config(a u32 value)for all the pins in the same group,
> so i removed the imx_group_set/get functions support, instead, using
> imx_pin_get/set.
> About this limitation, we may need some futher discussion on if we may
> need to enhance it to be more flexible to support configure different
> pins in the same group.
> * Refactor probe handling based on Stephen's suggestion.
> * Enhanced the binding doc and split it into two part, pinctrl-imx common part
> and pinctrl-soc driver part.
> * Change functions name from imx_pmx_* to imx_pinctrl_*.
> * Other fixes based on Sascha, Stephen, Linus, Shawn's comments.
> ---
Hi Shawn & Sascha,

Please help review if this can meet your requirement.

Regards
Dong Aisheg



\
 
 \ /
  Last update: 2012-04-26 16:43    [W:0.177 / U:0.260 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site