MAX7301 GPIO: Do not force SPI speed when using OF Platform

MAX7301 GPIO: Do not force SPI speed when using OF Platform

[Roland Stigge]

Hi,

commit 047b93a35961f7a6561e6f5dcb040738f822b892 introduced the following
to gpio-max7301.c:

	/* bits_per_word cannot be configured in platform data */
-	spi->bits_per_word = 16;
+	if (spi->dev.platform_data)
+		spi->bits_per_word = 16;
 	ret = spi_setup(spi);

Comment is: "The bit_per_word can be set in the OF Device tree, so no
need to force it as with the platform_data when using OF Platform"

Can you please point me to the respective OF option? I couldn't find it
under drivers/spi/spi* or Documentation/devicetree/bindings/spi/*.

Thanks in advance,

Roland

MAX7301 GPIO: Do not force SPI speed when using OF Platform

[leroy christophe]

Hi,

You have to add the following in your dts:

spi-bits = <16>;

Regards
Christophe

Le 24/07/2013 12:19, Roland Stigge a ?crit :
> Hi,
>
> commit 047b93a35961f7a6561e6f5dcb040738f822b892 introduced the following
> to gpio-max7301.c:
>
> 	/* bits_per_word cannot be configured in platform data */
> -	spi->bits_per_word = 16;
> +	if (spi->dev.platform_data)
> +		spi->bits_per_word = 16;
>   	ret = spi_setup(spi);
>
> Comment is: "The bit_per_word can be set in the OF Device tree, so no
> need to force it as with the platform_data when using OF Platform"
>
> Can you please point me to the respective OF option? I couldn't find it
> under drivers/spi/spi* or Documentation/devicetree/bindings/spi/*.
>
> Thanks in advance,
>
> Roland
>

MAX7301 GPIO: Do not force SPI speed when using OF Platform

[Roland Stigge]

Hi,

On 08/07/2013 01:31 PM, leroy christophe wrote:
> Le 24/07/2013 12:19, Roland Stigge a ?crit :
>> commit 047b93a35961f7a6561e6f5dcb040738f822b892 introduced the following
>> to gpio-max7301.c:
>>
>>     /* bits_per_word cannot be configured in platform data */
>> -    spi->bits_per_word = 16;
>> +    if (spi->dev.platform_data)
>> +        spi->bits_per_word = 16;
>>       ret = spi_setup(spi);
>>
>> Comment is: "The bit_per_word can be set in the OF Device tree, so no
>> need to force it as with the platform_data when using OF Platform"
>>
>> Can you please point me to the respective OF option? I couldn't find it
>> under drivers/spi/spi* or Documentation/devicetree/bindings/spi/*.
> 
> You have to add the following in your dts:
> 
> spi-bits = <16>;

I tried this, both in the device's and in the controller's node. But it
didn't work. However, as described, I didn't expect it to work, because
there is no code present to handle "spi-bits". At least not in 3.10.

Am I missing something? Otherwise, maybe something of the tree that you
are talking about is missing from mainline still?

Thanks in advance,

Roland

MAX7301 GPIO: Do not force SPI speed when using OF Platform

[leroy christophe]

Le 07/08/2013 14:17, Roland Stigge a ?crit :
> Hi,
>
> On 08/07/2013 01:31 PM, leroy christophe wrote:
>> Le 24/07/2013 12:19, Roland Stigge a ?crit :
>>> commit 047b93a35961f7a6561e6f5dcb040738f822b892 introduced the following
>>> to gpio-max7301.c:
>>>
>>>      /* bits_per_word cannot be configured in platform data */
>>> -    spi->bits_per_word = 16;
>>> +    if (spi->dev.platform_data)
>>> +        spi->bits_per_word = 16;
>>>        ret = spi_setup(spi);
>>>
>>> Comment is: "The bit_per_word can be set in the OF Device tree, so no
>>> need to force it as with the platform_data when using OF Platform"
>>>
>>> Can you please point me to the respective OF option? I couldn't find it
>>> under drivers/spi/spi* or Documentation/devicetree/bindings/spi/*.
>> You have to add the following in your dts:
>>
>> spi-bits = <16>;
> I tried this, both in the device's and in the controller's node. But it
> didn't work. However, as described, I didn't expect it to work, because
> there is no code present to handle "spi-bits". At least not in 3.10.
>
> Am I missing something? Otherwise, maybe something of the tree that you
> are talking about is missing from mainline still?
>
> Thanks in advance,
>
> Roland
>
Strange. I'm using 3.8.13
I have it handled in drivers/spi/spi.c in function of_register_spi_devices()

Christophe

MAX7301 GPIO: Do not force SPI speed when using OF Platform

[Roland Stigge]

Hi,

On 08/07/2013 02:35 PM, leroy christophe wrote:
>>> spi-bits = <16>;
>> I tried this, both in the device's and in the controller's node. But it
>> didn't work. However, as described, I didn't expect it to work, because
>> there is no code present to handle "spi-bits". At least not in 3.10.
>>
>> Am I missing something? Otherwise, maybe something of the tree that you
>> are talking about is missing from mainline still?
>>
>>
> Strange. I'm using 3.8.13
> I have it handled in drivers/spi/spi.c in function
> of_register_spi_devices()

3.8.13's (as well as newer ones') drivers/spi/spi.c doesn't handle
"spi-bits", see also

https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/drivers/spi/spi.c?h=linux-3.8.y

Maybe you have additional patches that are not in mainline, yet?

Thanks,

Roland

MAX7301 GPIO: Do not force SPI speed when using OF Platform

[leroy christophe]

Hi,

Le 07/08/2013 14:46, Roland Stigge a ?crit :
> Hi,
>
> On 08/07/2013 02:35 PM, leroy christophe wrote:
>>>> spi-bits = <16>;
>>> I tried this, both in the device's and in the controller's node. But it
>>> didn't work. However, as described, I didn't expect it to work, because
>>> there is no code present to handle "spi-bits". At least not in 3.10.
>>>
>>> Am I missing something? Otherwise, maybe something of the tree that you
>>> are talking about is missing from mainline still?
>>>
>>>
>> Strange. I'm using 3.8.13
>> I have it handled in drivers/spi/spi.c in function
>> of_register_spi_devices()
> 3.8.13's (as well as newer ones') drivers/spi/spi.c doesn't handle
> "spi-bits", see also
>
> https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/drivers/spi/spi.c?h=linux-3.8.y
>
> Maybe you have additional patches that are not in mainline, yet?
>
> Thanks,
>
> Roland
>
Yes you are right, I have the attached patch in addition which have been 
in our code for long time and which has never been submitted for 
inclusion in the mainline kernel.
Sorry about that, I will submit it.

Regards
Christophe
-------------- next part --------------
--- linux-3.8.13/drivers/spi/spi.c	2013-05-11 22:57:46.000000000 +0200
+++ linux/drivers/spi/spi.c	2013-08-06 18:15:34.000000000 +0200
@@ -870,6 +870,11 @@
 		if (of_find_property(nc, "spi-3wire", NULL))
 			spi->mode |= SPI_3WIRE;
 
+		/* Bits per word */
+		prop = of_get_property(nc, "spi-bits", &len);
+		if (prop && len >= sizeof(*prop)) {
+			spi->bits_per_word = prop[0];
+		}
 		/* Device speed */
 		prop = of_get_property(nc, "spi-max-frequency", &len);
 		if (!prop || len < sizeof(*prop)) {