linux-kernel - Re: [PATCH 4/4] iio: proximity: vl53l0x-i2c: Use raw I2C access and read full device ID

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2495ad98-79ca-486f-ab80-03344a55d2f2@kernel.org>
Date: Tue, 20 Jan 2026 11:42:51 +0100
From: Krzysztof Kozlowski <krzk@...nel.org>
To: petr.hodina@...tonmail.com, Song Qiang <songqiang1304521@...il.com>,
 Jonathan Cameron <jic23@...nel.org>, David Lechner <dlechner@...libre.com>,
 Nuno Sá <nuno.sa@...log.com>,
 Andy Shevchenko <andy@...nel.org>, Rob Herring <robh@...nel.org>,
 Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley
 <conor+dt@...nel.org>, Liam Girdwood <lgirdwood@...il.com>,
 Mark Brown <broonie@...nel.org>, David Heidelberg <david@...t.cz>
Cc: linux-iio@...r.kernel.org, devicetree@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/4] iio: proximity: vl53l0x-i2c: Use raw I2C access and
 read full device ID

On 19/01/2026 18:19, Petr Hodina via B4 Relay wrote:
> diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c
> index 6901ce7dd835..a2de4cc16a43 100644
> --- a/drivers/iio/proximity/vl53l0x-i2c.c
> +++ b/drivers/iio/proximity/vl53l0x-i2c.c
> @@ -320,11 +320,35 @@ static const struct iio_trigger_ops vl53l0x_trigger_ops = {
>  	.validate_device = iio_trigger_validate_own_device,
>  };
>  
> +

Do not introduce stray blank lines.

> +static int vl53l0x_read_word(struct i2c_client *client, u8 reg, u16 *val)
> +{
> +	int ret;
> +	u8 buf[2];
> +
> +	ret = i2c_master_send(client, &reg, 1);
> +	if (ret < 0)
> +		return ret;
> +	if (ret != 1)
> +		return -EIO;
> +
> +	ret = i2c_master_recv(client, buf, 2);
> +	if (ret < 0)
> +		return ret;
> +	if (ret != 2)
> +		return -EIO;
> +
> +	*val = (buf[0] << 8) | buf[1];
> +
> +	return 0;
> +}
> +
>  static int vl53l0x_probe(struct i2c_client *client)
>  {
>  	struct vl53l0x_data *data;
>  	struct iio_dev *indio_dev;
>  	int ret;
> +	u16 model, rev;
>  
>  	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>  	if (!indio_dev)
> @@ -339,13 +363,6 @@ static int vl53l0x_probe(struct i2c_client *client)
>  				     I2C_FUNC_SMBUS_BYTE_DATA))
>  		return -EOPNOTSUPP;
>  
> -	ret = i2c_smbus_read_byte_data(data->client, VL_REG_IDENTIFICATION_MODEL_ID);
> -	if (ret < 0)
> -		return -EINVAL;
> -
> -	if (ret != VL53L0X_MODEL_ID_VAL)
> -		dev_info(&client->dev, "Unknown model id: 0x%x", ret);
> -
>  	data->vdd_supply = devm_regulator_get(&client->dev, "vdd");
>  	if (IS_ERR(data->vdd_supply))
>  		return dev_err_probe(&client->dev, PTR_ERR(data->vdd_supply),
> @@ -372,6 +389,20 @@ static int vl53l0x_probe(struct i2c_client *client)
>  	if (ret)
>  		return ret;
>  
> +	ret = vl53l0x_read_word(client, 0xC0, &model);
> +	if (ret)
> +		return dev_err_probe(&client->dev, ret, "Failed to read model ID\n");
> +
> +	ret = vl53l0x_read_word(client, 0xC2, &rev);
> +	if (ret)
> +		return dev_err_probe(&client->dev, ret, "Failed to read revision ID\n");
> +
> +	dev_info(&client->dev, "VL53L0X model=0x%04x rev=0x%04x\n", model, rev);

dev_dbg

This does not look like useful printk message. Drivers should be silent
on success:
https://elixir.bootlin.com/linux/v6.15-rc7/source/Documentation/process/coding-style.rst#L913
https://elixir.bootlin.com/linux/v6.15-rc7/source/Documentation/process/debugging/driver_development_debugging_guide.rst#L79

Best regards,
Krzysztof