Received-SPF: pass (google.com: domain of linux-kernel+bounces-106400-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Message-ID: <e7ae980c-8408-46e3-909d-29b3d7e1e050@amperemail.onmicrosoft.com>
Date: Mon, 18 Mar 2024 23:50:37 +0700
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 3/3] dt-bindings: hwmon: max31790: Add
 pwmout-pin-as-tach-input property
Content-Language: en-US
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
 Chanh Nguyen <chanh@os.amperecomputing.com>, Jean Delvare
 <jdelvare@suse.com>, Guenter Roeck <linux@roeck-us.net>,
 Rob Herring <robh+dt@kernel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
 Conor Dooley <conor+dt@kernel.org>, Justin Ledford
 <justinledford@google.com>, devicetree@vger.kernel.org,
 linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org,
 OpenBMC Maillist <openbmc@lists.ozlabs.org>,
 Open Source Submission <patches@amperecomputing.com>
Cc: Phong Vo <phong@os.amperecomputing.com>,
 Thang Nguyen <thang@os.amperecomputing.com>,
 Quan Nguyen <quan@os.amperecomputing.com>
References: <20240311111347.23067-1-chanh@os.amperecomputing.com>
 <20240311111347.23067-4-chanh@os.amperecomputing.com>
 <9d1207f1-4941-4f2a-99d6-371f5b4709f5@linaro.org>
 <f281d2b1-54ff-4e5a-83b9-5b05f18c40fb@amperemail.onmicrosoft.com>
 <7252305b-4c7c-4cec-8ef1-8bf96293b469@linaro.org>
From: Chanh Nguyen <chanh@amperemail.onmicrosoft.com>
In-Reply-To: <7252305b-4c7c-4cec-8ef1-8bf96293b469@linaro.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0:
	=?utf-8?B?c0RGV2ZvQ001eWR1aDJGS3JwSkFvNlhTbUJUcGVIMVZmZXhUMlJWcnNmQncw?=
 =?utf-8?B?SitTR1JFb0NiMVg0ckpPR1ZOY1RiUFFOVzNxSytLcFNvdm13VWpLendtVGNW?=
 =?utf-8?B?TTFUUlZLcjZyL1BiTnFFb3dyUSt2bWl3UXp4c1lxNm9pblpwMlg0elNpcUNK?=
 =?utf-8?B?cUdJNHdXSy9HUlNsUmhSNjZYOXJrTTk3eXp1OWc3Q1g3L1J6VHRPQlVWY1BT?=
 =?utf-8?B?OFV5UXdhOGgva2s2bmtSbDdJVUJMd1pXN3A3VUU1NzJkWUJWaHUrcnZZV0Nw?=
 =?utf-8?B?c2k4RHRIdGs1NzhwQWh2aGRmbG5sQ3RsWFZmbmdhZHN6U1dYd3hXVjFncTFy?=
 =?utf-8?B?ck4wRFhqeVNCTFhuT1g2OE5WL3p4bi9FSU5YR2R2KzdHOTU0b0NSYTV6YVZ2?=
 =?utf-8?B?OUk1RTZqRXMrbDBHZHRoTHJhTFRScXkwSkdiWGZDaklxZGlRRDc1Zmc3V0FJ?=
 =?utf-8?B?SGIxckdpVkd2dXZFUVhob2dtK0VPUktQVk1zUkpOdzVwL1ZsZ1pjSG5wM3pH?=
 =?utf-8?B?VUNRRkJNOG1lZVVJd3dGWkZ4aU5iMGhNZktKeElyTW5oSGs1SXhKSUVtZzlj?=
 =?utf-8?B?ZDFKMmdzYzhOVVIwNGFWWjgyTWY0Z2l1SmV5TFRRaEFrRjBtMHJzNm9pbytI?=
 =?utf-8?B?VnVZL25JeFRYUVRmYnNUdm5qUC9MMFJzeStTN1FyMU05TXNHOUk5ZUFhVHVm?=
 =?utf-8?B?YmVnWXhqVUlDdnlHblBOSC9NQWEvYmlLUzRqOUdLR2hOSUt5NTBVVCsrMkho?=
 =?utf-8?B?ZkZIYmw5NXVmb2JjSytjMDViM3RMQ1N3MjBGa3JFQ2tKYUFrZWFMNHVlSUYw?=
 =?utf-8?B?RkRhZzA4U24zQUNMNG1nbVllVStCenVXOG5XNWY2L2g1SGNVMHFUMDN6QUxa?=
 =?utf-8?B?QkgyaDk4VHlEeXVhZllwWGJTMlBHbkNwYXg1Y0hKNkpvdEpzK3ZhR3V3dUZI?=
 =?utf-8?B?SW9KemFIaWFOc255b2h5NlZ0Vmk4cG5vVmR2MVJLanlhNW9XdU1aZFl2QWMz?=
 =?utf-8?B?S1RrNmRTMVJzSDBBZ0x0aWREMGQrNjkyTlNzQ0QwVEY4VGVpRDZGeGVoTlJs?=
 =?utf-8?B?THk0Sm5QTzMrZitza2hVSFZ0dTQrdE5WMkc0UW85STlScHZHcXNiRjJIQmRG?=
 =?utf-8?B?ZUlodTBuTmJyYWdvZzZaRzFXM29HU0VzZVZIaWpIaG5SRGRoTlBib2dCN3hq?=
 =?utf-8?B?OGQyZG5oYWZLYWpId051ZUg0VVVIVWFJTVlobi9mYXhZNlJlTFdqMGMyeXp2?=
 =?utf-8?B?ZUFpcmNUODdzdEkyN1N4Z0NqSlRHVzhJdGRiZlZGcnVBaFFFSlFrWDJ0MUNP?=
 =?utf-8?B?OHF6eHdOdjFCK090bjdaQkV0WUk0Q0F1N1A1bC8yTGRPSFZaRm4yOEthb21F?=
 =?utf-8?B?VSs4dGFIMjJUR09KSnVxd0dybVh0MlRoWVM1MmIyTXZFaURRYUxGMmFHb3VO?=
 =?utf-8?B?S3pPVUdRRVpNakNPQzJEaGkrcTRUZTU3aVhJTXhjVVRsdHhjK3djNjVRWC9M?=
 =?utf-8?B?MmZKYlBVa0hiUjM4aDBTeWtISnE2WmJpbDVOTDUrVlNhamlTQmZycHdacDdQ?=
 =?utf-8?B?bEJiM1dmTVJVWGdvL01uT2xPdGJRMDFIbXBwMDN2Skxnd0VISWRGUDNoYUxC?=
 =?utf-8?B?YmFPc2NTM1ZNVXNBamh2MHF3L1BEYk5aU3dacUZmcW1EOW80bjBhaFlGU05H?=
 =?utf-8?B?YUp0VzdmVmRsL0VnKzJnckJnUjZrR1JrSXkxTGpJeFVYby9Pdndqb3JXOW10?=
 =?utf-8?B?cEFLMlpUVkpVSDZ1MEZLQjhiVzVBVVJUTnlSbFVNZHY0a01hZUVTUHRjSGlF?=
 =?utf-8?B?Y25FV1duelBqVUozRkRKdDhCbzcwYlJHSENUNUdtVVZVaXpzRnBucG1QVTRo?=
 =?utf-8?B?QjVrbndXUGRTeWt0S0VZaUQvMTFUOTdiUlNaSFpDWmdyRTRoaVo3TW9oZHNm?=
 =?utf-8?B?aG4vWDMvdGcrVDIxTUJSWm52WklwZ2hQQnprL1FzNWxJU2tNeWtUNVF4ME04?=
 =?utf-8?B?VWZHL2FJdFVNb2xQNGZsSTFuZWNZM1pKZDIvRUVTdllCRFpCYVAvSTV1U0E5?=
 =?utf-8?B?QlBEa3crVnFyVjRMbFA5aGV2VmRObGxDaFVOQklCZVY0bHFtL0IyM1YrdXdQ?=
 =?utf-8?B?cVF3M01BSk1JeFNrWDJBcEJBVWFPalBhN216UGNwRXMwNW1EZTUwWUdUc3Bu?=
 =?utf-8?Q?GGENGJHs2jXTz6dSGrdBYrI=3D?=
X-OriginatorOrg: amperemail.onmicrosoft.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 505d79d1-8c4c-4e6d-6806-08dc476b90c4
X-MS-Exchange-CrossTenant-AuthSource: DM6PR01MB5947.prod.exchangelabs.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Mar 2024 16:50:49.8441
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3bc2b170-fd94-476d-b0ce-4229bdc904a7
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: +yl9N8Mht5+P49FyQTaNaahitdq/sh74CYs5iTGSXQKH0G6Az4J5zLtog5tmj4l7yi9mknIIkgu0mZfvSLqRiWWzG66aDe/AUT99nbhbR2DT+7py77+LeATODNwXFOU8
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR01MB8251


On 18/03/2024 17:02, Krzysztof Kozlowski wrote:
> On 18/03/2024 10:48, Chanh Nguyen wrote:
>>
>>
>> On 11/03/2024 23:56, Krzysztof Kozlowski wrote:
>>> On 11/03/2024 12:13, Chanh Nguyen wrote:
>>>> Add pwmout-pin-as-tach-input property.
>>>
>>> Why is this split from original binding? This does not make much
>>> sense... Add complete hardware description.
>>>
>>
>> Ok Krzysztof, I will merg the "[PATCH 1/3] dt-bindings: hwmon: Add maxim
>> max31790 driver bindings" commit and "[PATCH 3/3] dt-bindings: hwmon:
>> max31790: Add pwmout-pin-as-tach-input property" commit.
> 
> Later I checked your driver code and this explains a bit. However first
> patch should explain that instead. The split is fine, but just lack of
> rationale is confusing.
> 

Thank Krzysztof. I'll try to explain in detail each patch in v2.

> 
>>
>>>>
>>>> Signed-off-by: Chanh Nguyen <chanh@os.amperecomputing.com>
>>>> ---
>>>>    Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
>>>>    1 file changed, 11 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>>> index 5a93e6bdebda..447cac17053a 100644
>>>> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>>> @@ -25,6 +25,16 @@ properties:
>>>>      reg:
>>>>        maxItems: 1
>>>>    
>>>> +  pwmout-pin-as-tach-input:
>>>> +    description: |
>>>> +      An array of six integers responds to six PWM channels for
>>>> +      configuring the pwm to tach mode.
>>>> +      When set to 0, the associated PWMOUT produces a PWM waveform for
>>>> +      control of fan speed. When set to 1, PWMOUT becomes a TACH input
>>>
>>> No vendor prefix, so generic property... but where is it defined?
>>>
>>
>> Thank Krzysztof! It is not generic property, I'll add the vendor prefix.
>>
>> I'll update the "pwmout-pin-as-tach-input" to
>> "maxim,pwmout-pin-as-tach-input" at v2.
> 
> Except that you should really look into common properties and use them.
> Or explain why do you need new property?
> 
> Best regards,
> Krzysztof
> 

I'm also discussing with Rob Herring that on patch 3/3, I checked in the 
Documentation/devicetree/bindings/hwmon/fan-common.yaml. I found the 
tach-ch property, but it seems to define the tach channel used for the 
fan. It does not match my purpose. I want to configure the PWM-OUT pin 
to become a TACH-IN pin. I wonder if I can use the tach-ch property for 
my purpose.