[PATCH v2 0/7] Change snvs rtc and poweroff to use syscon add pwrkey driver

[Zhi Li]

On Wed, May 20, 2015 at 1:30 PM, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:
> On Wed, May 20, 2015 at 07:25:41PM +0100, Russell King - ARM Linux wrote:
>> On Wed, May 20, 2015 at 09:58:51AM +0800, Shawn Guo wrote:
>> > On Wed, May 20, 2015 at 01:04:35AM +0800, Frank.Li at freescale.com wrote:
>> > > Frank Li (6):
>> > >   arm: imx: power-off: change to syscon to access register
>> > >   rtc: arm: imx: snvs: change use syscon to access register
>> > >   Document: dt: fsl: snvs: change support syscon
>> > >   arm: dts: imx: update snvs to use syscon access register
>> > >   document: devicetree: input: imx: i.mx snvs power device tree bindings
>> > >   arm: dts: imx6sx: enable snvs power key
>> >
>> > So, the series will break existing DTBs for RTC and poweroff, right?
>> > If this is unavoidable, should we at least have some warning messages
>> > telling users about his breakage?
>>
>> What's the justification for breaking existing DTBs?  Really, this is
>> something we should strive to avoid, _and_ actually avoid by providing
>> backwards compatibility.
>
> Looking at the RTC code, it would be pretty trivial to do.
>
> Rather than passing around struct regmap, pass around the private data
> structure.
>
> Rename the regmap_* function calls to be private accessors.  Implement
> a set of new accessors - if the private data has the regmap, use the
> regmap API.  Otherwise, use the old method, and print a warning that an
> old DT is being used.

This method work.  But code will become ugly and complex. I seach
whole dts tree.
Only imx6 use this driver.

Does it really valuable to keep compatiblity with cost of complex driver code?

best regards
Frank Li

>
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