Re: [PATCH] iio: mma8452: Fix probe failing when an i2c_device_id is used

[Jonathan Cameron <jic23@kernel.org>]

On Thu,  6 Jan 2022 12:14:14 +0100
Hans de Goede <hdegoede@redhat.com> wrote:

> The mma8452_driver declares both of_match_table and i2c_driver.id_table
> match-tables, but its probe() function only checked for of matches.
> 
> Add support for i2c_device_id matches. This fixes the driver not loading
> on some x86 tablets (e.g. the Nextbook Ares 8) where the i2c_client is
> instantiated by platform code using an i2c_device_id.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Hi Hans,

At some point we'll want to get rid of the of_ specific stuff in here in
favour of generic firmware properties and I suspect at that time we'll
move the device name into the chip_info_table[] entries so that we
can just use device_get_match_data()

In the meantime this fix looks good to me.  Is there an appropriate
Fixes: tag?

Thanks,

Jonathan


> ---
>  drivers/iio/accel/mma8452.c | 23 +++++++++++++++--------
>  1 file changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
> index 09c7f10fefb6..c82841c0a7b3 100644
> --- a/drivers/iio/accel/mma8452.c
> +++ b/drivers/iio/accel/mma8452.c
> @@ -1523,12 +1523,7 @@ static int mma8452_probe(struct i2c_client *client,
>  	struct iio_dev *indio_dev;
>  	int ret;
>  	const struct of_device_id *match;
> -
> -	match = of_match_device(mma8452_dt_ids, &client->dev);
> -	if (!match) {
> -		dev_err(&client->dev, "unknown device model\n");
> -		return -ENODEV;
> -	}
> +	const char *compatible;
>  
>  	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>  	if (!indio_dev)
> @@ -1537,7 +1532,19 @@ static int mma8452_probe(struct i2c_client *client,
>  	data = iio_priv(indio_dev);
>  	data->client = client;
>  	mutex_init(&data->lock);
> -	data->chip_info = match->data;
> +
> +	if (id) {
> +		compatible = id->name;
> +		data->chip_info = &mma_chip_info_table[id->driver_data];
> +	} else {
> +		match = of_match_device(mma8452_dt_ids, &client->dev);
> +		if (!match) {
> +			dev_err(&client->dev, "unknown device model\n");
> +			return -ENODEV;
> +		}
> +		compatible = match->compatible;
> +		data->chip_info = match->data;
> +	}
>  
>  	data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
>  	if (IS_ERR(data->vdd_reg))
> @@ -1581,7 +1588,7 @@ static int mma8452_probe(struct i2c_client *client,
>  	}
>  
>  	dev_info(&client->dev, "registering %s accelerometer; ID 0x%x\n",
> -		 match->compatible, data->chip_info->chip_id);
> +		 compatible, data->chip_info->chip_id);
>  
>  	i2c_set_clientdata(client, indio_dev);
>  	indio_dev->info = &mma8452_info;