linux-kernel - Re: [PATCH v2 2/2] hwmon: (hs3001) Add driver for Renesas HS3001

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Message-ID: <fb19946c-b95c-cfd1-1034-7542d38e554e@linaro.org>
Date:   Tue, 18 Jul 2023 09:25:30 +0200
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Andre Werner <werneazc@...il.com>, jdelvare@...e.com,
        linux@...ck-us.net, krzysztof.kozlowski+dt@...aro.org,
        conor+dt@...nel.org, robh+dt@...nel.org
Cc:     linux-hwmon@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Andre Werner <andre.werner@...tec-electronic.com>
Subject: Re: [PATCH v2 2/2] hwmon: (hs3001) Add driver for Renesas HS3001

On 18/07/2023 09:01, Andre Werner wrote:
> Add base support for Renesas HS3001 temperature
> and humidity sensors and its compatibles HS3002,
> HS3003 and HS3004.
> 
> The sensor has a fix I2C address 0x44. The resolution
> is fixed to 14bit (ref. Missing feature).
> 

> Missing feature:
> - Accessing non-volatile memory: Custom board has no
>   possibility to control voltage supply of sensor. Thus,
>   we cannot send the necessary control commands within
>   the first 10ms after power-on.
> 
> Signed-off-by: Andre Werner <andre.werner@...tec-electronic.com>
> 
> Changelog:
> v1: Initial version
> v2: Extensive refactoring following recommendations of reviewers:
>  - Delete unused defines and device properties. These are added in
>    the initial version because the device supports a programming mode,
>    but I was not able to implement it, because the custom board was
>    not able to control the power supply of the device and so I cannot
>    enter the programming mode of the device.
>  - Correct missunderstanding comments for defines.
>  - Delete mutexes for data and I2C bus accesses.
>  - Replace attributes with recommented chip-info structure. In the
>    initial version I followed the sth3x.c implementation that uses
>    files and attributes in sysfs. The show functions are replaced by
>    is_visible and read callbacks from the HWMON ABI. I also  delete pointless
>    function argument checks.
>  - Correct Yoda programming.
>  - Refactor probe function and delete sleep and measurement of humidity
>    and temperature in probe function. I kept an initial I2C
>    communication to ensure that the device is accessible during probe.
>  - Reduce the number of atteributes to humidity and temperature input.

Also wrong placement of SoB and changelog.

> ---
>  Documentation/hwmon/hs3001.rst |  37 +++++
>  MAINTAINERS                    |   6 +
>  drivers/hwmon/Kconfig          |  10 ++
>  drivers/hwmon/Makefile         |   1 +
>  drivers/hwmon/hs3001.c         | 261 +++++++++++++++++++++++++++++++++
>  5 files changed, 315 insertions(+)
>  create mode 100644 Documentation/hwmon/hs3001.rst
>  create mode 100644 drivers/hwmon/hs3001.c

...

> +/* Definitions for Status Bits of A/D Data */
> +#define HS3001_DATA_VALID	0x00	/* Valid Data */
> +#define HS3001_DATA_STALE	0x01	/* Stale Data */
> +
> +#define LIMIT_MAX	0
> +#define LIMIT_MIN	1
> +
> +enum hs3001_chips {
> +	hs3001,

Drop, not effectively used.

> +};

...

> +
> +/* device ID table */
> +static const struct i2c_device_id hs3001_ids[] = {
> +	{ "hs3001", hs3001 },

Drop match data

> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, hs3001_ids);
> +
> +static const struct of_device_id hs3001_of_match[] = {
> +	{.compatible = "renesas,hs3001",
> +	 .data = (void *)hs3001

Drop

> +	},
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, hs3001_of_match);
> +
> +static int hs3001_probe(struct i2c_client *client)
> +{
> +	struct hs3001_data *data;
> +	struct device *hwmon_dev;
> +	struct device *dev = &client->dev;
> +	int ret;
> +
> +	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
> +		return -EOPNOTSUPP;
> +
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->client = client;
> +
> +	if (client->dev.of_node)
> +		data->type = (enum hs3001_chips)of_device_get_match_data(&client->dev);
> +	else
> +		data->type = i2c_match_id(hs3001_ids, client)->driver_data;

This is useless and dead code. You have only one type of device. Don't
over-complicate simple things.



Best regards,
Krzysztof