Received-SPF: pass (google.com: domain of linux-kernel+bounces-197674-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Sender: Guenter Roeck <groeck7@gmail.com>
Message-ID: <e5d95d3d-1ca5-43f1-8c17-d24bd38f28b7@roeck-us.net>
Date: Fri, 31 May 2024 20:40:11 -0700
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v3 2/4] hwmon: Add support for SPD5118 compliant
 temperature sensors
To: Wolfram Sang <wsa+renesas@sang-engineering.com>,
 linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org,
 Rob Herring <robh@kernel.org>, Krzysztof Kozlowski <krzk+dt@kernel.org>,
 Conor Dooley <conor+dt@kernel.org>, linux-kernel@vger.kernel.org,
 Armin Wolf <W_Armin@gmx.de>, =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?=
 <linux@weissschuh.net>, =?UTF-8?Q?Ren=C3=A9_Rebe?= <rene@exactcode.de>
References: <20240531230556.1409532-1-linux@roeck-us.net>
 <20240531230556.1409532-3-linux@roeck-us.net>
 <uvikiflwuoz3szchmvke7p3ymqvcngkydehk6cctdv24cxsh6r@7d5vxcvdca6l>
Content-Language: en-US
From: Guenter Roeck <linux@roeck-us.net>
Autocrypt: addr=linux@roeck-us.net; keydata=
 xsFNBE6H1WcBEACu6jIcw5kZ5dGeJ7E7B2uweQR/4FGxH10/H1O1+ApmcQ9i87XdZQiB9cpN
 RYHA7RCEK2dh6dDccykQk3bC90xXMPg+O3R+C/SkwcnUak1UZaeK/SwQbq/t0tkMzYDRxfJ7
 nyFiKxUehbNF3r9qlJgPqONwX5vJy4/GvDHdddSCxV41P/ejsZ8PykxyJs98UWhF54tGRWFl
 7i1xvaDB9lN5WTLRKSO7wICuLiSz5WZHXMkyF4d+/O5ll7yz/o/JxK5vO/sduYDIlFTvBZDh
 gzaEtNf5tQjsjG4io8E0Yq0ViobLkS2RTNZT8ICq/Jmvl0SpbHRvYwa2DhNsK0YjHFQBB0FX
 IdhdUEzNefcNcYvqigJpdICoP2e4yJSyflHFO4dr0OrdnGLe1Zi/8Xo/2+M1dSSEt196rXaC
 kwu2KgIgmkRBb3cp2vIBBIIowU8W3qC1+w+RdMUrZxKGWJ3juwcgveJlzMpMZNyM1jobSXZ0
 VHGMNJ3MwXlrEFPXaYJgibcg6brM6wGfX/LBvc/haWw4yO24lT5eitm4UBdIy9pKkKmHHh7s
 jfZJkB5fWKVdoCv/omy6UyH6ykLOPFugl+hVL2Prf8xrXuZe1CMS7ID9Lc8FaL1ROIN/W8Vk
 BIsJMaWOhks//7d92Uf3EArDlDShwR2+D+AMon8NULuLBHiEUQARAQABzTJHdWVudGVyIFJv
 ZWNrIChMaW51eCBhY2NvdW50KSA8bGludXhAcm9lY2stdXMubmV0PsLBgQQTAQIAKwIbAwYL
 CQgHAwIGFQgCCQoLBBYCAwECHgECF4ACGQEFAlVcphcFCRmg06EACgkQyx8mb86fmYFg0RAA
 nzXJzuPkLJaOmSIzPAqqnutACchT/meCOgMEpS5oLf6xn5ySZkl23OxuhpMZTVX+49c9pvBx
 hpvl5bCWFu5qC1jC2eWRYU+aZZE4sxMaAGeWenQJsiG9lP8wkfCJP3ockNu0ZXXAXwIbY1O1
 c+l11zQkZw89zNgWgKobKzrDMBFOYtAh0pAInZ9TSn7oA4Ctejouo5wUugmk8MrDtUVXmEA9
 7f9fgKYSwl/H7dfKKsS1bDOpyJlqhEAH94BHJdK/b1tzwJCFAXFhMlmlbYEk8kWjcxQgDWMu
 GAthQzSuAyhqyZwFcOlMCNbAcTSQawSo3B9yM9mHJne5RrAbVz4TWLnEaX8gA5xK3uCNCeyI
 sqYuzA4OzcMwnnTASvzsGZoYHTFP3DQwf2nzxD6yBGCfwNGIYfS0i8YN8XcBgEcDFMWpOQhT
 Pu3HeztMnF3HXrc0t7e5rDW9zCh3k2PA6D2NV4fews9KDFhLlTfCVzf0PS1dRVVWM+4jVl6l
 HRIAgWp+2/f8dx5vPc4Ycp4IsZN0l1h9uT7qm1KTwz+sSl1zOqKD/BpfGNZfLRRxrXthvvY8
 BltcuZ4+PGFTcRkMytUbMDFMF9Cjd2W9dXD35PEtvj8wnEyzIos8bbgtLrGTv/SYhmPpahJA
 l8hPhYvmAvpOmusUUyB30StsHIU2LLccUPPOwU0ETofVZwEQALlLbQeBDTDbwQYrj0gbx3bq
 7kpKABxN2MqeuqGr02DpS9883d/t7ontxasXoEz2GTioevvRmllJlPQERVxM8gQoNg22twF7
 pB/zsrIjxkE9heE4wYfN1AyzT+AxgYN6f8hVQ7Nrc9XgZZe+8IkuW/Nf64KzNJXnSH4u6nJM
 J2+Dt274YoFcXR1nG76Q259mKwzbCukKbd6piL+VsT/qBrLhZe9Ivbjq5WMdkQKnP7gYKCAi
 pNVJC4enWfivZsYupMd9qn7Uv/oCZDYoBTdMSBUblaLMwlcjnPpOYK5rfHvC4opxl+P/Vzyz
 6WC2TLkPtKvYvXmdsI6rnEI4Uucg0Au/Ulg7aqqKhzGPIbVaL+U0Wk82nz6hz+WP2ggTrY1w
 ZlPlRt8WM9w6WfLf2j+PuGklj37m+KvaOEfLsF1v464dSpy1tQVHhhp8LFTxh/6RWkRIR2uF
 I4v3Xu/k5D0LhaZHpQ4C+xKsQxpTGuYh2tnRaRL14YMW1dlI3HfeB2gj7Yc8XdHh9vkpPyuT
 nY/ZsFbnvBtiw7GchKKri2gDhRb2QNNDyBnQn5mRFw7CyuFclAksOdV/sdpQnYlYcRQWOUGY
 HhQ5eqTRZjm9z+qQe/T0HQpmiPTqQcIaG/edgKVTUjITfA7AJMKLQHgp04Vylb+G6jocnQQX
 JqvvP09whbqrABEBAAHCwWUEGAECAA8CGwwFAlVcpi8FCRmg08MACgkQyx8mb86fmYHNRQ/+
 J0OZsBYP4leJvQF8lx9zif+v4ZY/6C9tTcUv/KNAE5leyrD4IKbnV4PnbrVhjq861it/zRQW
 cFpWQszZyWRwNPWUUz7ejmm9lAwPbr8xWT4qMSA43VKQ7ZCeTQJ4TC8kjqtcbw41SjkjrcTG
 wF52zFO4bOWyovVAPncvV9eGA/vtnd3xEZXQiSt91kBSqK28yjxAqK/c3G6i7IX2rg6pzgqh
 hiH3/1qM2M/LSuqAv0Rwrt/k+pZXE+B4Ud42hwmMr0TfhNxG+X7YKvjKC+SjPjqp0CaztQ0H
 nsDLSLElVROxCd9m8CAUuHplgmR3seYCOrT4jriMFBtKNPtj2EE4DNV4s7k0Zy+6iRQ8G8ng
 QjsSqYJx8iAR8JRB7Gm2rQOMv8lSRdjva++GT0VLXtHULdlzg8VjDnFZ3lfz5PWEOeIMk7Rj
 trjv82EZtrhLuLjHRCaG50OOm0hwPSk1J64R8O3HjSLdertmw7eyAYOo4RuWJguYMg5DRnBk
 WkRwrSuCn7UG+qVWZeKEsFKFOkynOs3pVbcbq1pxbhk3TRWCGRU5JolI4ohy/7JV1TVbjiDI
 HP/aVnm6NC8of26P40Pg8EdAhajZnHHjA7FrJXsy3cyIGqvg9os4rNkUWmrCfLLsZDHD8FnU
 mDW4+i+XlNFUPUYMrIKi9joBhu18ssf5i5Q=
In-Reply-To: <uvikiflwuoz3szchmvke7p3ymqvcngkydehk6cctdv24cxsh6r@7d5vxcvdca6l>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

On 5/31/24 18:28, Wolfram Sang wrote:
> 
>> +/* Return 0 if detection is successful, -ENODEV otherwise */
>> +static int spd5118_detect(struct i2c_client *client, struct i2c_board_info *info)
>> +{
>> +	struct i2c_adapter *adapter = client->adapter;
>> +	int regval;
>> +
>> +	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
>> +				     I2C_FUNC_SMBUS_WORD_DATA))
>> +		return -ENODEV;
>> +
>> +	regval = i2c_smbus_read_word_swapped(client, SPD5118_REG_TYPE);
>> +	if (regval != 0x5118)
>> +		return -ENODEV;
>> +
>> +	regval = i2c_smbus_read_word_data(client, SPD5118_REG_VENDOR);
>> +	if (regval < 0 || !spd5118_vendor_valid(regval & 0xff, regval >> 8))
>> +		return -ENODEV;
>> +
>> +	regval = i2c_smbus_read_byte_data(client, SPD5118_REG_CAPABILITY);
>> +	if (regval < 0)
>> +		return -ENODEV;
>> +	if (!(regval & SPD5118_CAP_TS_SUPPORT) || (regval & 0xfc))
>> +		return -ENODEV;
>> +
>> +	regval = i2c_smbus_read_byte_data(client, SPD5118_REG_TEMP_CLR);
>> +	if (regval)
>> +		return -ENODEV;
>> +	regval = i2c_smbus_read_byte_data(client, SPD5118_REG_ERROR_CLR);
>> +	if (regval)
>> +		return -ENODEV;
>> +
>> +	regval = i2c_smbus_read_byte_data(client, SPD5118_REG_REVISION);
>> +	if (regval < 0 || (regval & 0xc1))
>> +		return -ENODEV;
>> +
>> +	regval = i2c_smbus_read_byte_data(client, SPD5118_REG_TEMP_CONFIG);
>> +	if (regval < 0)
>> +		return -ENODEV;
>> +	if (regval & ~SPD5118_TS_DISABLE)
>> +		return -ENODEV;
>> +
>> +	strscpy(info->type, "spd5118", I2C_NAME_SIZE);
>> +	return 0;
>> +}
> 
> What about adding DDR5 to i2c_register_spd() and dropping this function?
> 

Yes, that should be the next step. I didn't want to do that here because it
would introduce a cross-subsystem dependency. Of course, that depends a bit
on your position about such dependencies. If I do that as part of this series,
would you Ack it, or would you want to handle that through the i2c tree ?

Guenter