Re: [Patch v1 2/2] iio: ak8975: Added ACPI enumeration

[Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

On 19/03/14 16:56, Srinivas Pandruvada wrote:
> Added capability so that this device can be enumerated via ACPI.
>
This is simple enough that I'm going to rely on my limited knowledge of ACPI and
take it as is.
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Applied to the togreg branch of iio.git

Thanks,

Jonathan
> ---
>   drivers/iio/magnetometer/ak8975.c | 40 ++++++++++++++++++++++++++++++++++++---
>   1 file changed, 37 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
> index aa7682d..09ea5c4 100644
> --- a/drivers/iio/magnetometer/ak8975.c
> +++ b/drivers/iio/magnetometer/ak8975.c
> @@ -31,6 +31,7 @@
>   #include <linux/bitops.h>
>   #include <linux/gpio.h>
>   #include <linux/of_gpio.h>
> +#include <linux/acpi.h>
>
>   #include <linux/iio/iio.h>
>   #include <linux/iio/sysfs.h>
> @@ -475,6 +476,27 @@ static const struct iio_info ak8975_info = {
>   	.driver_module = THIS_MODULE,
>   };
>
> +static const struct acpi_device_id ak_acpi_match[] = {
> +	{"AK8975", AK8975},
> +	{"AK8963", AK8963},
> +	{"INVN6500", AK8963},
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
> +
> +static char *ak8975_match_acpi_device(struct device *dev,
> +				enum asahi_compass_chipset *chipset)
> +{
> +	const struct acpi_device_id *id;
> +
> +	id = acpi_match_device(dev->driver->acpi_match_table, dev);
> +	if (!id)
> +		return NULL;
> +	*chipset = (int)id->driver_data;
> +
> +	return (char *)dev_name(dev);
> +}
> +
>   static int ak8975_probe(struct i2c_client *client,
>   			const struct i2c_device_id *id)
>   {
> @@ -482,6 +504,7 @@ static int ak8975_probe(struct i2c_client *client,
>   	struct iio_dev *indio_dev;
>   	int eoc_gpio;
>   	int err;
> +	char *name = NULL;
>
>   	/* Grab and set up the supplied GPIO. */
>   	if (client->dev.platform_data)
> @@ -519,8 +542,18 @@ static int ak8975_probe(struct i2c_client *client,
>   	data->eoc_gpio = eoc_gpio;
>   	data->eoc_irq = 0;
>
> -	data->chipset = (enum asahi_compass_chipset)(id->driver_data);
> -	dev_dbg(&client->dev, "Asahi compass chip %s\n", id->name);
> +	/* id will be NULL when enumerated via ACPI */
> +	if (id) {
> +		data->chipset =
> +			(enum asahi_compass_chipset)(id->driver_data);
> +		name = (char *) id->name;
> +	} else if (ACPI_HANDLE(&client->dev))
> +		name = ak8975_match_acpi_device(&client->dev, &data->chipset);
> +	else {
> +		err = -ENOSYS;
> +		goto exit_free_iio;
> +	}
> +	dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
>
>   	/* Perform some basic start-of-day setup of the device. */
>   	err = ak8975_setup(client);
> @@ -537,7 +570,7 @@ static int ak8975_probe(struct i2c_client *client,
>   	indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
>   	indio_dev->info = &ak8975_info;
>   	indio_dev->modes = INDIO_DIRECT_MODE;
> -
> +	indio_dev->name = name;
>   	err = iio_device_register(indio_dev);
>   	if (err < 0)
>   		goto exit_free_iio;
> @@ -592,6 +625,7 @@ static struct i2c_driver ak8975_driver = {
>   	.driver = {
>   		.name	= "ak8975",
>   		.of_match_table = ak8975_of_match,
> +		.acpi_match_table = ACPI_PTR(ak_acpi_match),
>   	},
>   	.probe		= ak8975_probe,
>   	.remove		= ak8975_remove,
>