Messages in this thread | | | Date | Thu, 26 Apr 2012 22:44:52 +0800 | From | Dong Aisheng <> | Subject | Re: [PATCH v3 2/4] pinctrl: pinctrl-imx: add imx pinctrl core driver |
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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
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