Re: [PATCH v2 1/6] iio: core: pass parent device as parameter during allocation

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 3 Jun 2020 14:40:18 +0300
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:

> The change passes the parent device to the iio_device_alloc() call. This
> also updates the devm_iio_device_alloc() call to consider the device object
> as the parent device by default.
> 
> Having it passed like this, should ensure that any IIO device object
> already has a device object as parent, allowing for neater control, like
> passing the 'indio_dev' object for other stuff [like buffers/triggers/etc],
> and potentially creating iiom_xxx(indio_dev) functions.
> 
> With this patch, only the 'drivers/platform/x86/toshiba_acpi.c' needs an
> update to pass the parent object as a parameter.
> 
> In the next patch all devm_iio_device_alloc() calls will be handled.
> 
> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

Applied to the togreg branch of iio.git and pushed out as testing
for the all the usual reasons.

Hmm. I should probably clear out that bit of docs that is left in staging.
I'd imagine they have rotted pretty badly and our main docs are probably
more useful.

Thanks,

Jonathan

> ---
>  drivers/iio/dummy/iio_simple_dummy.c         | 14 ++++++++------
>  drivers/iio/industrialio-core.c              | 11 ++++++-----
>  drivers/platform/x86/toshiba_acpi.c          |  3 +--
>  drivers/staging/iio/Documentation/device.txt |  4 +---
>  include/linux/iio/iio.h                      |  4 ++--
>  5 files changed, 18 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/iio/dummy/iio_simple_dummy.c b/drivers/iio/dummy/iio_simple_dummy.c
> index 6cb02299a215..b35ae7c039f7 100644
> --- a/drivers/iio/dummy/iio_simple_dummy.c
> +++ b/drivers/iio/dummy/iio_simple_dummy.c
> @@ -566,6 +566,13 @@ static struct iio_sw_device *iio_dummy_probe(const char *name)
>  	struct iio_dev *indio_dev;
>  	struct iio_dummy_state *st;
>  	struct iio_sw_device *swd;
> +	struct device *parent = NULL;
> +
> +	/*
> +	 * With hardware: Set the parent device.
> +	 * parent = &spi->dev;
> +	 * parent = &client->dev;
> +	 */
>  
>  	swd = kzalloc(sizeof(*swd), GFP_KERNEL);
>  	if (!swd) {
> @@ -580,7 +587,7 @@ static struct iio_sw_device *iio_dummy_probe(const char *name)
>  	 * It also has a region (accessed by iio_priv()
>  	 * for chip specific state information.
>  	 */
> -	indio_dev = iio_device_alloc(sizeof(*st));
> +	indio_dev = iio_device_alloc(parent, sizeof(*st));
>  	if (!indio_dev) {
>  		ret = -ENOMEM;
>  		goto error_ret;
> @@ -590,11 +597,6 @@ static struct iio_sw_device *iio_dummy_probe(const char *name)
>  	mutex_init(&st->lock);
>  
>  	iio_dummy_init_device(indio_dev);
> -	/*
> -	 * With hardware: Set the parent device.
> -	 * indio_dev->dev.parent = &spi->dev;
> -	 * indio_dev->dev.parent = &client->dev;
> -	 */
>  
>  	 /*
>  	 * Make the iio_dev struct available to remove function.
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 1527f01a44f1..75661661aaba 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1493,7 +1493,7 @@ struct device_type iio_device_type = {
>   * iio_device_alloc() - allocate an iio_dev from a driver
>   * @sizeof_priv:	Space to allocate for private structure.
>   **/
> -struct iio_dev *iio_device_alloc(int sizeof_priv)
> +struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
>  {
>  	struct iio_dev *dev;
>  	size_t alloc_size;
> @@ -1510,6 +1510,7 @@ struct iio_dev *iio_device_alloc(int sizeof_priv)
>  	if (!dev)
>  		return NULL;
>  
> +	dev->dev.parent = parent;
>  	dev->dev.groups = dev->groups;
>  	dev->dev.type = &iio_device_type;
>  	dev->dev.bus = &iio_bus_type;
> @@ -1551,7 +1552,7 @@ static void devm_iio_device_release(struct device *dev, void *res)
>  
>  /**
>   * devm_iio_device_alloc - Resource-managed iio_device_alloc()
> - * @dev:		Device to allocate iio_dev for
> + * @parent:		Device to allocate iio_dev for, and parent for this IIO device
>   * @sizeof_priv:	Space to allocate for private structure.
>   *
>   * Managed iio_device_alloc. iio_dev allocated with this function is
> @@ -1560,7 +1561,7 @@ static void devm_iio_device_release(struct device *dev, void *res)
>   * RETURNS:
>   * Pointer to allocated iio_dev on success, NULL on failure.
>   */
> -struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
> +struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv)
>  {
>  	struct iio_dev **ptr, *iio_dev;
>  
> @@ -1569,10 +1570,10 @@ struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
>  	if (!ptr)
>  		return NULL;
>  
> -	iio_dev = iio_device_alloc(sizeof_priv);
> +	iio_dev = iio_device_alloc(parent, sizeof_priv);
>  	if (iio_dev) {
>  		*ptr = iio_dev;
> -		devres_add(dev, ptr);
> +		devres_add(parent, ptr);
>  	} else {
>  		devres_free(ptr);
>  	}
> diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
> index 808944546739..4a4d09c352dd 100644
> --- a/drivers/platform/x86/toshiba_acpi.c
> +++ b/drivers/platform/x86/toshiba_acpi.c
> @@ -3128,7 +3128,7 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
>  
>  	toshiba_accelerometer_available(dev);
>  	if (dev->accelerometer_supported) {
> -		dev->indio_dev = iio_device_alloc(sizeof(*dev));
> +		dev->indio_dev = iio_device_alloc(&acpi_dev->dev, sizeof(*dev));
>  		if (!dev->indio_dev) {
>  			pr_err("Unable to allocate iio device\n");
>  			goto iio_error;
> @@ -3138,7 +3138,6 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
>  
>  		dev->indio_dev->info = &toshiba_iio_accel_info;
>  		dev->indio_dev->name = "Toshiba accelerometer";
> -		dev->indio_dev->dev.parent = &acpi_dev->dev;
>  		dev->indio_dev->modes = INDIO_DIRECT_MODE;
>  		dev->indio_dev->channels = toshiba_iio_accel_channels;
>  		dev->indio_dev->num_channels =
> diff --git a/drivers/staging/iio/Documentation/device.txt b/drivers/staging/iio/Documentation/device.txt
> index ec42544a46aa..0d1275b1eb3f 100644
> --- a/drivers/staging/iio/Documentation/device.txt
> +++ b/drivers/staging/iio/Documentation/device.txt
> @@ -8,7 +8,7 @@ The crucial structure for device drivers in iio is iio_dev.
>  
>  First allocate one using:
>  
> -struct iio_dev *indio_dev = iio_device_alloc(sizeof(struct chip_state));
> +struct iio_dev *indio_dev = iio_device_alloc(parent, sizeof(struct chip_state));
>  where chip_state is a structure of local state data for this instance of
>  the chip.
>  
> @@ -16,8 +16,6 @@ That data can be accessed using iio_priv(struct iio_dev *).
>  
>  Then fill in the following:
>  
> -- indio_dev->dev.parent
> -	Struct device associated with the underlying hardware.
>  - indio_dev->name
>  	Name of the device being driven - made available as the name
>  	attribute in sysfs.
> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
> index a1be82e74c93..91a69f4751aa 100644
> --- a/include/linux/iio/iio.h
> +++ b/include/linux/iio/iio.h
> @@ -676,7 +676,7 @@ static inline void *iio_device_get_drvdata(struct iio_dev *indio_dev)
>  
>  /* Can we make this smaller? */
>  #define IIO_ALIGN L1_CACHE_BYTES
> -struct iio_dev *iio_device_alloc(int sizeof_priv);
> +struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv);
>  
>  static inline void *iio_priv(const struct iio_dev *indio_dev)
>  {
> @@ -690,7 +690,7 @@ static inline struct iio_dev *iio_priv_to_dev(void *priv)
>  }
>  
>  void iio_device_free(struct iio_dev *indio_dev);
> -struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv);
> +struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv);
>  struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
>  						const char *fmt, ...);
>  /**