Message-ID: <013cc486-dc70-a8b9-69d2-d0ae991549fd@linaro.org>
Date:   Tue, 14 Feb 2023 08:46:54 +0100
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Subject: Re: [PATCH v4 3/3] i2c: aspeed: support ast2600 i2c new register mode
 driver
To:     Ryan Chen <ryan_chen@aspeedtech.com>, Jeremy Kerr <jk@ozlabs.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Joel Stanley <joel@jms.id.au>,
        Andrew Jeffery <andrew@aj.id.au>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        "openbmc@lists.ozlabs.org" <openbmc@lists.ozlabs.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-aspeed@lists.ozlabs.org" <linux-aspeed@lists.ozlabs.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <20230201103359.1742140-1-ryan_chen@aspeedtech.com>
 <20230201103359.1742140-4-ryan_chen@aspeedtech.com>
 <30c7cbbf57abbdfb5f974d6ee17b2218d124c7e8.camel@ozlabs.org>
 <SEZPR06MB526941A3DDB25529F0671112F2D69@SEZPR06MB5269.apcprd06.prod.outlook.com>
 <5239ea2f-284a-dcf5-6dd4-be3b13b319e6@linaro.org>
 <SEZPR06MB526951F24B841965C0DD6B84F2D69@SEZPR06MB5269.apcprd06.prod.outlook.com>
 <SEZPR06MB52698009DA893813FECBE76FF2A29@SEZPR06MB5269.apcprd06.prod.outlook.com>
Content-Language: en-US
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <SEZPR06MB52698009DA893813FECBE76FF2A29@SEZPR06MB5269.apcprd06.prod.outlook.com>
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On 14/02/2023 07:12, Ryan Chen wrote:
> Hello Krzysztof,
>>
>>> On 02/02/2023 10:16, Ryan Chen wrote:
>>>>>>> +static struct platform_driver ast2600_i2c_global_driver = {
>>>>>> +       .probe  = ast2600_i2c_global_probe,
>>>>>> +       .driver = {
>>>>>> +               .name = KBUILD_MODNAME,
>>>>>> +               .of_match_table =
>> ast2600_i2c_global_of_match,
>>>>>> +       },
>>>>>> +};
>>>>>> +
>>>>>> +static int __init ast2600_i2c_global_init(void) {
>>>>>> +       return
>>>>>> +platform_driver_register(&ast2600_i2c_global_driver);
>>>>>> +}
>>>>>> +device_initcall(ast2600_i2c_global_init);
>>>>>
>>>>> Maybe module_platform_driver() instead?
>>>>
>>>> Due to i2c global is top of all i2c bus like the scu, it make sure
>>>> the driver is
>>> before the i2c bus driver probe.
>>>> It is needed use device_initcal function.
>>>
>>> No, we do not do such ordering. device links and proper resource
>>> sharing handle the order. This must be module_platform_driver()
>>> (assuming we do not drop entire submission).
>>
>>
>> If global driver use module_platform_driver, does i2c driver will latter the
>> global driver probe?
>> If yes, I think it will workable.
>>>
> I find a good way instead. 
> subsys_initcall(ast2600_i2c_global_init); is better ?

Not really, this is not a subsystem. This is module platform driver so
use it.

Best regards,
Krzysztof