Re: [PATCH v2 2/5] Power: reset: add bindings for keystone reset driver

From: Ivan Khoronzhuk
Date: Mon May 05 2014 - 14:54:28 EST



On 04/15/2014 02:25 PM, Ivan Khoronzhuk wrote:

On 04/14/2014 09:44 PM, Arnd Bergmann wrote:
On Monday 14 April 2014 20:41:20 Ivan Khoronzhuk wrote:
+Optional properties:
+
+- ti,soft-reset: Boolean option indicating soft reset.
+ By default hard reset is used.
+
+- ti,wdt_list: WDT list that can cause SoC reset.
+ The list in format: <0>, <2>;
+ Begins from 0 to 3, as keystone can contain up
+ to 4 SoC reset watchdogs.

This looks like your binding just describes a subset of the
watchdog timer registers. If so, don't do a standalone reset

The registers are not a subset of watchdog hardware it's SoC specific future
controlled by SoC specific registers (bootregs and PLL regs).

For watchog IP setup, the Keystone uses the watchdog driver common with other
SoCs -- davinci_watchdog that is not depend on other SoC settings like this driver does.

The Keystone SoCs have separate registers to tune Keystone2 reset functionality
by configuring Reset multiplexer & PLL. And it tunes not only watchdog usage.
The keystone SoC can be rebooted in several ways. By external reset pin, by soft and
by watchdogs. This driver allows software reset or reset by one of the watchdogs
(and other settings) independently on watchdog driver settings. This is job of reset driver.

It's
driver, but instead do a watchdog driver that can also be
used for reset, and have a binding that properly describes
the watchdog hardware.

It is bad to have overlapping register ranges between logical

WDT doesn't overlap with this driver.

devices, and it's also generally wrong to describe devices that
are not actually there: The hardware contains a watchdog, not
a system-reset device, so you should not make one up because
it seems easier given the Linux driver model.

Arnd

Hi Arnd,

Could I do smth additional to make bindings explanation more clear?
Or this is enough?

I can write like the following:
Optional properties:

- ti,soft-reset: Boolean option indicating soft reset.
By default hard reset is used.

- ti,wdt_list: WDT list that can cause SoC reset. This is not
related to WDT driver, it's just needed to enable
a SoC related reset that is triggered by one of watchdogs.
The list in format: <0>, <2>;
Begins from 0 to 3, as keystone can contain up
to 4 SoC reset watchdogs. Can be in random order.

That is OK?

--
Regards,
Ivan Khoronzhuk

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