From: Prashant Gaikwad <pgaikwad@nvidia.com>
To: Stephen Warren <swarren@wwwdotorg.org>
Cc: "mturquette@linaro.org" <mturquette@linaro.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>
Subject: Re: [PATCH v2 05/11] ARM: dt: tegra30: Add device node for APB MISC
Date: Fri, 4 Jan 2013 11:01:58 +0530 [thread overview]
Message-ID: <50E6694E.2050704@nvidia.com> (raw)
In-Reply-To: <50E666C0.50200@wwwdotorg.org>
On Friday 04 January 2013 10:51 AM, Stephen Warren wrote:
> On 01/03/2013 09:26 PM, Prashant Gaikwad wrote:
>> On Friday 04 January 2013 09:30 AM, Stephen Warren wrote:
>>> On 01/03/2013 08:23 PM, Prashant Gaikwad wrote:
>>>> On Friday 04 January 2013 08:35 AM, Stephen Warren wrote:
>>>>> On 01/03/2013 06:48 PM, Prashant Gaikwad wrote:
>>>>>> On Thursday 03 January 2013 09:41 PM, Stephen Warren wrote:
>>> ...
>>>>>>> OK. It sounds like we need a true APB MISC driver then, to
>>>>>>> abstract the
>>>>>>> differences; the clock driver really shouldn't be touching the APB
>>>>>>> MISC
>>>>>>> registers in all likelihood, unless a subset of the sections you
>>>>>>> mention
>>>>>>> above are truly dedicated to clock functionality.
>>>>>> I don't think it is a good idea to create a driver for APB MISC, all
>>>>>> registers are used by different drivers.
>>>>> Well, it's even worse to have a bunch of other drivers randomly trample
>>>>> on a set of registers they don't own.
>>>>>
>>>>>> Only chip id revision registers are used in clock driver.
>>>>> There are already global variables exposed by the Tegra fuse driver;
>>>>> can
>>>>> you just read those?
>>>> It is not about variables or some value, we have to read some apb
>>>> register to flush the write operation in apb bus before we disable
>>>> peripheral clock.
>>>> We are using chip id revision register for this purpose.
>>> Ah. That's definitely not something the clock driver should be doing
>>> directly. It's probably OK to add a custom Tegra-specific function to
>>> some file in arch/arm/mach-tegra to implement this. Even better would be
>>> a full bus driver for the APB bus, but that's probably too much bloat
>>> for now.
>> tegra_init_fuse in arch/arm/mach-tegra/fuse.c is already reading chip id
>> revision register, so I can implement one function to read this register
>> in fuse.c, which will be used by clock driver and tegra_init_fuse.
>> But then we need to add it to some header file in include/mach or
>> include/linux, where? any suggestion?
> Somewhere other than arch/arm/mach-tega/include/mach/ would be good, so
> we don't have to move it later when we enable multi-platform zImage for
> Tegra. Perhaps include/linux/tegra-soc.h? I guess we could move the
> existing mach/powergate.h contents into that file later too.
include/linux/tegra-soc.h seems fine, I will send updated patch series.
next prev parent reply other threads:[~2013-01-04 5:32 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-27 14:47 [PATCH v2 00/11] Migrate Tegra to common clock framework Prashant Gaikwad
2012-12-27 14:47 ` [PATCH v2 01/11] clk: tegra: Add tegra specific clocks Prashant Gaikwad
2013-01-07 12:13 ` Peter De Schrijver
2012-12-27 14:47 ` [PATCH v2 02/11] arm: tegra: Move tegra_cpu_car.h to linux/clk/tegra.h Prashant Gaikwad
2012-12-27 14:47 ` [PATCH v2 03/11] ARM: tegra: Define Tegra20 CAR binding Prashant Gaikwad
2012-12-27 14:47 ` [PATCH v2 04/11] ARM: Tegra: Define Tegra30 " Prashant Gaikwad
2013-01-09 14:41 ` Peter De Schrijver
2012-12-27 14:47 ` [PATCH v2 05/11] ARM: dt: tegra30: Add device node for APB MISC Prashant Gaikwad
2013-01-02 22:00 ` Stephen Warren
2013-01-03 6:11 ` Prashant Gaikwad
2013-01-03 16:11 ` Stephen Warren
2013-01-04 1:48 ` Prashant Gaikwad
2013-01-04 3:05 ` Stephen Warren
2013-01-04 3:23 ` Prashant Gaikwad
2013-01-04 4:00 ` Stephen Warren
2013-01-04 4:26 ` Prashant Gaikwad
2013-01-04 5:21 ` Stephen Warren
2013-01-04 5:31 ` Prashant Gaikwad [this message]
2013-01-04 11:56 ` Laxman Dewangan
2013-01-04 19:57 ` Stephen Warren
2012-12-27 14:47 ` [PATCH v2 06/11] ARM: dt: tegra20: " Prashant Gaikwad
2012-12-27 14:47 ` [PATCH v2 07/11] clk: tegra: add clock support for tegra20 Prashant Gaikwad
2012-12-27 14:47 ` [PATCH v2 08/11] clk: tegra: add clock support for tegra30 Prashant Gaikwad
2013-01-07 14:54 ` Peter De Schrijver
2012-12-27 14:47 ` [PATCH v2 09/11] clk: tegra: add dt support Prashant Gaikwad
2013-01-02 22:06 ` Stephen Warren
2012-12-27 14:47 ` [PATCH v2 10/11] arm: tegra: Migrate to new clock code Prashant Gaikwad
2012-12-27 14:47 ` [PATCH v2 11/11] arm: tegra: Remove legacy " Prashant Gaikwad
2013-01-02 22:09 ` [PATCH v2 00/11] Migrate Tegra to common clock framework Stephen Warren
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