diff mbox

[PATCHv2,2/4] arm/dts: omap5-evm: Add tmp102 sensor support

Message ID 1344852313-30484-3-git-send-email-sourav.poddar@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Poddar, Sourav Aug. 13, 2012, 10:05 a.m. UTC
Add tmp102 temperature sensor data in omap5 evm dts file.

Tested on omap5430 evm with 3.5 custom kernel.

Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
---
 arch/arm/boot/dts/omap5-evm.dts |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

Comments

Benoit Cousson Aug. 14, 2012, 9:56 a.m. UTC | #1
On 08/13/2012 12:05 PM, Sourav Poddar wrote:
> Add tmp102 temperature sensor data in omap5 evm dts file.
> 
> Tested on omap5430 evm with 3.5 custom kernel.
> 
> Cc: Benoit Cousson <b-cousson@ti.com>
> Cc: Felipe Balbi <balbi@ti.com>
> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
> Acked-by: Felipe Balbi <balbi@ti.com>
> Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
> ---
>  arch/arm/boot/dts/omap5-evm.dts |    9 +++++++++
>  1 files changed, 9 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/omap5-evm.dts b/arch/arm/boot/dts/omap5-evm.dts
> index 200c39a..45a8aeb 100644
> --- a/arch/arm/boot/dts/omap5-evm.dts
> +++ b/arch/arm/boot/dts/omap5-evm.dts
> @@ -18,3 +18,12 @@
>  		reg = <0x80000000 0x40000000>; /* 1 GB */
>  	};
>  };
> +
> +&i2c4 {
> +	clock-frequency = <400000>;

Have you checked if we cannot run at faster speed? Reducing the speed
will impact every devices on the bus.
It might be needed, I just wanted to be sure.

You should maybe just add a small comment to explain what the device is
doing with potentially a link to the HW spec if available.

The same comments are applicable to the bmp085 patch.

Regards,
Benoit

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Felipe Balbi Aug. 14, 2012, 9:59 a.m. UTC | #2
On Tue, Aug 14, 2012 at 11:56:45AM +0200, Benoit Cousson wrote:
> On 08/13/2012 12:05 PM, Sourav Poddar wrote:
> > Add tmp102 temperature sensor data in omap5 evm dts file.
> > 
> > Tested on omap5430 evm with 3.5 custom kernel.
> > 
> > Cc: Benoit Cousson <b-cousson@ti.com>
> > Cc: Felipe Balbi <balbi@ti.com>
> > Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
> > Acked-by: Felipe Balbi <balbi@ti.com>
> > Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
> > ---
> >  arch/arm/boot/dts/omap5-evm.dts |    9 +++++++++
> >  1 files changed, 9 insertions(+), 0 deletions(-)
> > 
> > diff --git a/arch/arm/boot/dts/omap5-evm.dts b/arch/arm/boot/dts/omap5-evm.dts
> > index 200c39a..45a8aeb 100644
> > --- a/arch/arm/boot/dts/omap5-evm.dts
> > +++ b/arch/arm/boot/dts/omap5-evm.dts
> > @@ -18,3 +18,12 @@
> >  		reg = <0x80000000 0x40000000>; /* 1 GB */
> >  	};
> >  };
> > +
> > +&i2c4 {
> > +	clock-frequency = <400000>;
> 
> Have you checked if we cannot run at faster speed? Reducing the speed
> will impact every devices on the bus.
> It might be needed, I just wanted to be sure.
> 
> You should maybe just add a small comment to explain what the device is
> doing with potentially a link to the HW spec if available.
> 
> The same comments are applicable to the bmp085 patch.

that sort of information should be placed on
Documentation/devicetree/bindings/*/$device.txt, right ? Why should we
replicate it on all dts files ? Besides, there are only two such entries
on all ARM DTS files. Do we really want to make dts files bigger with
links to documentation which can even be moved at any time to other
location by the manufacturer's choice ? Will anyone actually keep track
of such links to make sure they aren't broken ? And even if someone does
track those links, do we really want to keep sending such patches for
the dts files ?
Benoit Cousson Aug. 14, 2012, 10:21 a.m. UTC | #3
Hi Felipe,

On 08/14/2012 11:59 AM, Felipe Balbi wrote:
> On Tue, Aug 14, 2012 at 11:56:45AM +0200, Benoit Cousson wrote:
>> On 08/13/2012 12:05 PM, Sourav Poddar wrote:
>>> Add tmp102 temperature sensor data in omap5 evm dts file.
>>>
>>> Tested on omap5430 evm with 3.5 custom kernel.
>>>
>>> Cc: Benoit Cousson <b-cousson@ti.com>
>>> Cc: Felipe Balbi <balbi@ti.com>
>>> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
>>> Acked-by: Felipe Balbi <balbi@ti.com>
>>> Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
>>> ---
>>>  arch/arm/boot/dts/omap5-evm.dts |    9 +++++++++
>>>  1 files changed, 9 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/arch/arm/boot/dts/omap5-evm.dts b/arch/arm/boot/dts/omap5-evm.dts
>>> index 200c39a..45a8aeb 100644
>>> --- a/arch/arm/boot/dts/omap5-evm.dts
>>> +++ b/arch/arm/boot/dts/omap5-evm.dts
>>> @@ -18,3 +18,12 @@
>>>  		reg = <0x80000000 0x40000000>; /* 1 GB */
>>>  	};
>>>  };
>>> +
>>> +&i2c4 {
>>> +	clock-frequency = <400000>;
>>
>> Have you checked if we cannot run at faster speed? Reducing the speed
>> will impact every devices on the bus.
>> It might be needed, I just wanted to be sure.
>>
>> You should maybe just add a small comment to explain what the device is
>> doing with potentially a link to the HW spec if available.
>>
>> The same comments are applicable to the bmp085 patch.
> 
> that sort of information should be placed on
> Documentation/devicetree/bindings/*/$device.txt, right ? Why should we
> replicate it on all dts files ? 

Well in that case, this is not part of the binding documentation, but
that can be a good idea to update the documentation indeed.

> Besides, there are only two such entries
> on all ARM DTS files. Do we really want to make dts files bigger with
> links to documentation which can even be moved at any time to other
> location by the manufacturer's choice ? Will anyone actually keep track
> of such links to make sure they aren't broken ? And even if someone does
> track those links, do we really want to keep sending such patches for
> the dts files ?

A little bit of comment and documentation will never hurt anybody and
will not have any impact on the DTB size. If that can save us some time
to avoid googling to know what device we are taking about, it is already
better than nothing.

Regards,
Benoit

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Poddar, Sourav Aug. 14, 2012, 10:27 a.m. UTC | #4
Hi Benoit,

On Tue, Aug 14, 2012 at 3:26 PM, Benoit Cousson <b-cousson@ti.com> wrote:
> On 08/13/2012 12:05 PM, Sourav Poddar wrote:
>> Add tmp102 temperature sensor data in omap5 evm dts file.
>>
>> Tested on omap5430 evm with 3.5 custom kernel.
>>
>> Cc: Benoit Cousson <b-cousson@ti.com>
>> Cc: Felipe Balbi <balbi@ti.com>
>> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
>> Acked-by: Felipe Balbi <balbi@ti.com>
>> Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
>> ---
>>  arch/arm/boot/dts/omap5-evm.dts |    9 +++++++++
>>  1 files changed, 9 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/arm/boot/dts/omap5-evm.dts b/arch/arm/boot/dts/omap5-evm.dts
>> index 200c39a..45a8aeb 100644
>> --- a/arch/arm/boot/dts/omap5-evm.dts
>> +++ b/arch/arm/boot/dts/omap5-evm.dts
>> @@ -18,3 +18,12 @@
>>               reg = <0x80000000 0x40000000>; /* 1 GB */
>>       };
>>  };
>> +
>> +&i2c4 {
>> +     clock-frequency = <400000>;
>
> Have you checked if we cannot run at faster speed? Reducing the speed
> will impact every devices on the bus.
> It might be needed, I just wanted to be sure.
>
Indeed, tmp 102(i2c4) and bmp085(i2c2) can run at speed upto 3.4 MHz.

Though, there are other devices on i2c2(tsl2771) and i2c4
(touchscreen) that will eventually come, support upto
400 KHz.  May be I will change this to 3.4 MHz for now?And when
tsl2771 and touch device are added, I will
change it back to 400 kHz??

~Sourav
> You should maybe just add a small comment to explain what the device is
> doing with potentially a link to the HW spec if available.
>
> The same comments are applicable to the bmp085 patch.
>
> Regards,
> Benoit
>
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diff mbox

Patch

diff --git a/arch/arm/boot/dts/omap5-evm.dts b/arch/arm/boot/dts/omap5-evm.dts
index 200c39a..45a8aeb 100644
--- a/arch/arm/boot/dts/omap5-evm.dts
+++ b/arch/arm/boot/dts/omap5-evm.dts
@@ -18,3 +18,12 @@ 
 		reg = <0x80000000 0x40000000>; /* 1 GB */
 	};
 };
+
+&i2c4 {
+	clock-frequency = <400000>;
+
+	tmp102@48{
+		compatible = "ti,tmp102";
+		reg = <0x48>;
+	};
+};