Re: [PATCH] of_i2c: I2C child node 10-bit client addressing

Re: [PATCH] of_i2c: I2C child node 10-bit client addressing

[Stephen Warren]

FYI, re:

> https://lists.ozlabs.org/pipermail/devicetree-discuss/2012-November/022645.html

I know that was a long time ago, but I was searching for information on
which chips supported 10-bit I2C addresses, and found a partial answer
to the question:

Grant Likely wrote:
> Is it possible for a device to have an address that fits in the first 7
> bits, but still requires 10 bit address transactions?

The following chip (link below) certainly supports a 10-bit I2C address
with the top-most 3 bits set to 0. Now, it does also respond to a 7-bit
I2C address of the same value, so this perhaps isn't quite an exact
answer to Grant's question. However, it does indicate to me that we
shouldn't determine whether to use 7- or 10-bit addresses solely from
the set bits in the I2C address; a separate property or flag bit in the
address field would be better, I think.

http://www.ti.com/lit/ds/snvs839/snvs839.pdf

Quoting it:

> 7-BIT and 10-BIT ADDRESSING MODES
>
> The LM8330 supports both the 7-bit and 10-bit addressing modes as defined in the NXP (Philips) I 2 C
> Specification UM10204 rev 0.3 from 2007. The default 7-bit slave address is 0x88, and the default 10-bit slave
> address is 0x088. NOTE: The upper three address bits in 10-bit mode are hard tied to 0.

[PATCH] of_i2c: I2C child node 10-bit client addressing

[bharat_404-PkbjNfxxIARBDgjK7y7TUQ]

From: Bharat Kumar Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>

I2C clients which has 10 bit address, struct i2c_board_info,
member "flags = I2C_CLIENT_TEN" is needed.

Signed-off-by: Bharat Kumar Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>

diff --git a/drivers/of/of_i2c.c b/drivers/of/of_i2c.c
index 3550f3b..28c5566 100644
--- a/drivers/of/of_i2c.c
+++ b/drivers/of/of_i2c.c
@@ -57,6 +57,10 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
 			continue;
 		}
 
+		/* Support for i2c 10 bit client address */
+		if ((info.addr > (1 << 7) - 1) && (info.addr <= (1 << 10) - 1))
+			info.flags = I2C_CLIENT_TEN;
+
 		info.irq = irq_of_parse_and_map(node, 0);
 		info.of_node = of_node_get(node);
 		info.archdata = &dev_ad;
-- 
1.7.6

Re: [PATCH] of_i2c: I2C child node 10-bit client addressing

[Grant Likely]

On Thu, Nov 15, 2012 at 9:35 AM,  <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org> wrote:
> From: Bharat Kumar Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>
>
> I2C clients which has 10 bit address, struct i2c_board_info,
> member "flags = I2C_CLIENT_TEN" is needed.
>
> Signed-off-by: Bharat Kumar Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>

Did you see my questions from yesterday?

g.

>
> diff --git a/drivers/of/of_i2c.c b/drivers/of/of_i2c.c
> index 3550f3b..28c5566 100644
> --- a/drivers/of/of_i2c.c
> +++ b/drivers/of/of_i2c.c
> @@ -57,6 +57,10 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
>                         continue;
>                 }
>
> +               /* Support for i2c 10 bit client address */
> +               if ((info.addr > (1 << 7) - 1) && (info.addr <= (1 << 10) - 1))
> +                       info.flags = I2C_CLIENT_TEN;
> +
>                 info.irq = irq_of_parse_and_map(node, 0);
>                 info.of_node = of_node_get(node);
>                 info.archdata = &dev_ad;
> --
> 1.7.6
>
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

RE: [PATCH] of_i2c: I2C child node 10-bit client addressing

[Bharat Reddy]

[-- Attachment #1.1: Type: text/plain, Size: 2011 bytes --]

I guess the I2C spec does not restricts.(A device to have an address that fits in the first 7 bits, but still requires 10 bit address transactions)

But I don't think their will be any I2C slave doing this. 

Why a 7 bit slave want to have extra byte for every transaction?

Note: I am on vacation with limited e-mail access. I will be back on Nov 26.

Thanks,
-Bharat


> From: grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org
> Date: Thu, 15 Nov 2012 16:53:59 +0000
> Subject: Re: [PATCH] of_i2c: I2C child node 10-bit client addressing
> To: bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org
> CC: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org; jochen-NIgtFMG+Po8@public.gmane.org; jonsmirl@gmail.com
> 
> On Thu, Nov 15, 2012 at 9:35 AM,  <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org> wrote:
> > From: Bharat Kumar Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>
> >
> > I2C clients which has 10 bit address, struct i2c_board_info,
> > member "flags = I2C_CLIENT_TEN" is needed.
> >
> > Signed-off-by: Bharat Kumar Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>
> 
> Did you see my questions from yesterday?
> 
> g.
> 
> >
> > diff --git a/drivers/of/of_i2c.c b/drivers/of/of_i2c.c
> > index 3550f3b..28c5566 100644
> > --- a/drivers/of/of_i2c.c
> > +++ b/drivers/of/of_i2c.c
> > @@ -57,6 +57,10 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
> >                         continue;
> >                 }
> >
> > +               /* Support for i2c 10 bit client address */
> > +               if ((info.addr > (1 << 7) - 1) && (info.addr <= (1 << 10) - 1))
> > +                       info.flags = I2C_CLIENT_TEN;
> > +
> >                 info.irq = irq_of_parse_and_map(node, 0);
> >                 info.of_node = of_node_get(node);
> >                 info.archdata = &dev_ad;
> > --
> > 1.7.6
> >
> >
> 
> 
> 
> -- 
> Grant Likely, B.Sc., P.Eng.
> Secret Lab Technologies Ltd.
 		 	   		  

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Re: [PATCH] of_i2c: I2C child node 10-bit client addressing

[Grant Likely]

On Fri, Nov 16, 2012 at 1:12 PM, Bharat Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org> wrote:
> I guess the I2C spec does not restricts.(A device to have an address that
> fits in the first 7 bits, but still requires 10 bit address transactions)
>
> But I don't think their will be any I2C slave doing this.
>
> Why a 7 bit slave want to have extra byte for every transaction?

It is possible for there to be devices that use 10 bit addressing, but
have a configurable address.

g.

>
> Note: I am on vacation with limited e-mail access. I will be back on Nov 26.
>
> Thanks,
> -Bharat
>
>
>> From: grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org
>> Date: Thu, 15 Nov 2012 16:53:59 +0000
>> Subject: Re: [PATCH] of_i2c: I2C child node 10-bit client addressing
>> To: bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org
>> CC: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org; jochen-NIgtFMG+Po8@public.gmane.org;
>> jonsmirl-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
>
>>
>> On Thu, Nov 15, 2012 at 9:35 AM, <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org> wrote:
>> > From: Bharat Kumar Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>
>> >
>> > I2C clients which has 10 bit address, struct i2c_board_info,
>> > member "flags = I2C_CLIENT_TEN" is needed.
>> >
>> > Signed-off-by: Bharat Kumar Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>
>>
>> Did you see my questions from yesterday?
>>
>> g.
>>
>> >
>> > diff --git a/drivers/of/of_i2c.c b/drivers/of/of_i2c.c
>> > index 3550f3b..28c5566 100644
>> > --- a/drivers/of/of_i2c.c
>> > +++ b/drivers/of/of_i2c.c
>> > @@ -57,6 +57,10 @@ void of_i2c_register_devices(struct i2c_adapter
>> > *adap)
>> > continue;
>> > }
>> >
>> > + /* Support for i2c 10 bit client address */
>> > + if ((info.addr > (1 << 7) - 1) && (info.addr <= (1 << 10) - 1))
>> > + info.flags = I2C_CLIENT_TEN;
>> > +
>> > info.irq = irq_of_parse_and_map(node, 0);
>> > info.of_node = of_node_get(node);
>> > info.archdata = &dev_ad;
>> > --
>> > 1.7.6
>> >
>> >
>>
>>
>>
>> --
>> Grant Likely, B.Sc., P.Eng.
>> Secret Lab Technologies Ltd.



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

[PATCH] of_i2c: I2C child node 10-bit client addressing

[Bharat Reddy]

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I2C clients which has 10 bit address, struct i2c_board_info,
member "flags = I2C_CLIENT_TEN" is needed.

Signed-off-by: Bharat Kumar Reddy Gooty <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>
---
 drivers/of/of_i2c.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/of/of_i2c.c b/drivers/of/of_i2c.c
index 1e173f3..9cda7e2 100644
--- a/drivers/of/of_i2c.c
+++ b/drivers/of/of_i2c.c
@@ -57,6 +57,10 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
                        continue;
                }   
 
+               /* Support for i2c 10 bit client address */
+               if ((info.addr > (1 << 7) - 1) && (info.addr <= (1 << 10) - 1))
+                       info.flags = I2C_CLIENT_TEN;
+
                info.irq = irq_of_parse_and_map(node, 0); 
                info.of_node = of_node_get(node);
                info.archdata = &dev_ad;
-- 
1.7.9.5


 		 	   		  

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Re: [PATCH] of_i2c: I2C child node 10-bit client addressing

[Grant Likely]

On Fri, 12 Oct 2012 09:12:48 +0530, Bharat Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org> wrote:
> I2C clients which has 10 bit address, struct i2c_board_info,
> member "flags = I2C_CLIENT_TEN" is needed.
> 
> Signed-off-by: Bharat Kumar Reddy Gooty <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>
> ---
>  drivers/of/of_i2c.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/of/of_i2c.c b/drivers/of/of_i2c.c
> index 1e173f3..9cda7e2 100644
> --- a/drivers/of/of_i2c.c
> +++ b/drivers/of/of_i2c.c
> @@ -57,6 +57,10 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
>                         continue;
>                 }   
>  
> +               /* Support for i2c 10 bit client address */
> +               if ((info.addr > (1 << 7) - 1) && (info.addr <= (1 << 10) - 1))
> +                       info.flags = I2C_CLIENT_TEN;
> +

Is it possible for a device to have an address that fits in the first 7
bits, but still requires 10 bit address transactions?

g.

Re: [PATCH] of_i2c: I2C child node 10-bit client addressing

[Grant Likely]

On Fri, 12 Oct 2012 09:12:48 +0530, Bharat Reddy <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org> wrote:
> I2C clients which has 10 bit address, struct i2c_board_info,
> member "flags = I2C_CLIENT_TEN" is needed.
> 
> Signed-off-by: Bharat Kumar Reddy Gooty <bharat_404-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>

Also, the patch appears to have been corrupted because it wasn't posted
as plain text. I can't easly apply things that are sent that way. What
are you using to email patches? (Cut-and-paste into an email client
generally doesn't work for submitting patches)

g.

> ---
>  drivers/of/of_i2c.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/of/of_i2c.c b/drivers/of/of_i2c.c
> index 1e173f3..9cda7e2 100644
> --- a/drivers/of/of_i2c.c
> +++ b/drivers/of/of_i2c.c
> @@ -57,6 +57,10 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
>                         continue;
>                 }   
>  
> +               /* Support for i2c 10 bit client address */
> +               if ((info.addr > (1 << 7) - 1) && (info.addr <= (1 << 10) - 1))
> +                       info.flags = I2C_CLIENT_TEN;
> +
>                 info.irq = irq_of_parse_and_map(node, 0); 
>                 info.of_node = of_node_get(node);
>                 info.archdata = &dev_ad;
> -- 
> 1.7.9.5
> 
> 
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-- 
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.