From: rnayak@codeaurora.org (Rajendra Nayak)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 5/9] clk: qcom: gcc-msm8960: add child devices support.
Date: Wed, 02 Sep 2015 08:07:42 +0530 [thread overview]
Message-ID: <55E660F6.3020007@codeaurora.org> (raw)
In-Reply-To: <55CD5BD2.3070907@codeaurora.org>
Stephen,
>>>>> Also, I don't like having a subnode in DT. Why can't we use the
>>>>> same node as the GCC node and create a virtual child device here
>>>>> for tsens? We can assign the same of_node that this platform
>>>>> device has so that DT keeps working correctly.
>>>
>>> So the current driver looks up data based on compatible strings.
>>
>> The tsens device is always the same piece of hardware. The only
>
> Well, not always. The one in 8960 does need additional initializations,
> requires you to save/restore context as it can be powered off
> not being in an always powered on domain etc.
>
>> thing that's changing is the qfprom data and the number of
>> sensors. So we should be looking at the qfprom compatible string
>
> How? Tsens uses nvmem framework apis to read the qfprom atleast
> in this series.
>
>> to figure out how to interpret the qfprom data which would
>> include the number of sensors and how the data is encoded.
>>
>>> So you suggesting to create a virtual child device for gcc and
>>> associate the gcc DT node to it? (And have the tsens compatible
>>> mentioned as part of the gcc DT node?)
>>
>> No. The driver should work just fine without having to
>> interrogate the device's compatible string. If we still need the
>> compatible check for some reason, then we can always match based
>> on qcom,gcc-msm8960, qcom,gcc-apq8064, etc. But I don't see why
>
> Thats not quite possible I guess. 2 drivers (gcc and tsens) matching
> the same compatibles? Will it not just depend on which ends up being
> the first match?
Any thoughts on how to move forward with this?
I tried what you were suggesting, and here's what I had to do to get
things working
* Created a gcc node in DT with gcc and tsens compatibles, with gcc and
tsens properties
* gcc driver probes the device/node first given gcc is registered with
a core_initcall()
* creates a virtual child device attaching the same of_node (having
both gcc and tsens compatibles)
* gcc ends up probing the virtual device/node _again_ (due to the gcc
compatible match), fails
* At a later point, tsens driver gets registered (using module_initcall)
ends up probing the virtual child node and succeeds
Is this what you had in mind, or am I at the wrong end of the stick?
regards,
Rajendra
next prev parent reply other threads:[~2015-09-02 2:37 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-08 9:47 [PATCH 0/9] qcom: Add support for TSENS driver Rajendra Nayak
2015-07-08 9:47 ` [PATCH 1/9] thermal: qcom: tsens: Add a skeletal TSENS drivers Rajendra Nayak
2015-07-08 9:47 ` [PATCH 2/9] thermal: qcom: tsens-8916: Add support for 8916 family of SoCs Rajendra Nayak
2015-07-08 9:47 ` [PATCH 3/9] thermal: qcom: tsens-8974: Add support for 8974 " Rajendra Nayak
2015-07-08 9:47 ` [PATCH 4/9] thermal: qcom: tsens-8960: Add support for 8960 " Rajendra Nayak
2015-07-08 9:47 ` [PATCH 5/9] clk: qcom: gcc-msm8960: add child devices support Rajendra Nayak
2015-08-11 22:49 ` Stephen Boyd
2015-08-12 9:00 ` Srinivas Kandagatla
2015-08-13 4:28 ` Rajendra Nayak
2015-08-14 0:42 ` Stephen Boyd
2015-08-14 3:09 ` Rajendra Nayak
2015-09-02 2:37 ` Rajendra Nayak [this message]
2015-09-03 17:27 ` Stephen Boyd
2015-09-07 6:39 ` Rajendra Nayak
2015-09-08 19:21 ` Stephen Boyd
2015-09-09 3:33 ` Rajendra Nayak
2015-09-09 5:15 ` Rajendra Nayak
2015-09-09 9:11 ` Srinivas Kandagatla
2015-08-12 20:18 ` Bjorn Andersson
2015-08-12 21:57 ` Stephen Boyd
2015-08-13 4:14 ` Bjorn Andersson
2015-08-14 0:46 ` Stephen Boyd
2015-07-08 9:47 ` [PATCH 6/9] arm: dts: msm8974: Add thermal zones, tsens and eeprom nodes Rajendra Nayak
2015-07-08 9:47 ` [PATCH 7/9] arm: dts: apq8064: " Rajendra Nayak
2015-07-08 9:47 ` [PATCH 8/9] arm: dts: apq8084: " Rajendra Nayak
2015-07-08 9:47 ` [PATCH 9/9] arm64: dts: msm8916: " Rajendra Nayak
2015-08-11 8:26 ` [PATCH 0/9] qcom: Add support for TSENS driver Srinivas Kandagatla
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