From: ludovic.desroches@atmel.com (ludovic.desroches)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] i2c: change the id to let the i2c-gpio work
Date: Mon, 15 Oct 2012 08:42:14 +0200 [thread overview]
Message-ID: <507BB046.8010702@atmel.com> (raw)
In-Reply-To: <507B7066.4060802@atmel.com>
Le 10/15/2012 04:09 AM, Bo Shen a ?crit :
> Hi Joachim Eastwood,
>
> On 10/13/2012 1:42, Joachim Eastwood wrote:
>> Hi Bo Shen,
>>
>> On Fri, Oct 12, 2012 at 11:42 AM, Bo Shen <voice.shen@atmel.com> wrote:
>>> The i2c-gpio driver will turn the platform device ID to busnum.
>>> When using platfrom device ID as -1, it means dynamically assigned
>>> the busnum. When writing code, we need to make sure the busnum,
>>> and call i2c_register_board_info(int busnum, ...) to register device
>>> if using -1, we do not know the value of busnum.
>>>
>>> In order to solve this issue, set the platform device ID as a fix number
>>> Here using 0 to match the busnum used in i2c_regsiter_board_info().
>>
>> I have been bitten by this myself on RM9200.
>>
>>> Signed-off-by: Bo Shen <voice.shen@atmel.com>
>>> ---
>>> Change since v1
>>> Make the commit message more clear
>>> ---
>>> arch/arm/mach-at91/at91sam9260_devices.c | 2 +-
>>
>> This pattern exist in at91rm9200_devices.c, at91sam9261_devices.c,
>> at91sam9263_devices.c and at91sam9rl_devices.c you might want to fix
>> them as well.
>
> Thanks for your information.
> After I test these boards, I will send patches to fix them, while not in
> this patch.
>
>>
>> I assume we have the same problem if CONFIG_I2C_AT91 is set?
>> See further down in at91sam9260_devices.c we have another: ".id = -1,"
>
> Maybe Nikolaus Voss will deal with this case.
>
Yes the problem is the same, I have encountered it and solved it in the
same way but I was thinking there was a better way to correct it than
removing dynamic id assignment.
Since setting the id to a fix value is acceptable this change can be
done also when using i2c-at91.
>>
>> regards
>> Joachim Eastwood
>>
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm/mach-at91/at91sam9260_devices.c
>>> b/arch/arm/mach-at91/at91sam9260_devices.c
>>> index 0f24cfb..805ef95 100644
>>> --- a/arch/arm/mach-at91/at91sam9260_devices.c
>>> +++ b/arch/arm/mach-at91/at91sam9260_devices.c
>>> @@ -389,7 +389,7 @@ static struct i2c_gpio_platform_data pdata = {
>>>
>>> static struct platform_device at91sam9260_twi_device = {
>>> .name = "i2c-gpio",
>>> - .id = -1,
>>> + .id = 0,
>>> .dev.platform_data = &pdata,
>>> };
>>>
>>> --
>>> 1.7.9.5
>>>
>>>
>>> _______________________________________________
>>> linux-arm-kernel mailing list
>>> linux-arm-kernel at lists.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
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>
next prev parent reply other threads:[~2012-10-15 6:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-12 9:42 [PATCH v2] i2c: change the id to let the i2c-gpio work Bo Shen
2012-10-12 9:57 ` Jean Delvare
2012-10-12 17:42 ` Joachim Eastwood
2012-10-15 2:09 ` Bo Shen
2012-10-15 6:42 ` ludovic.desroches [this message]
2012-10-15 8:12 ` Nicolas Ferre
2012-10-15 8:26 ` Bo Shen
2012-10-15 8:30 ` Nicolas Ferre
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