On Wed, Mar 13, 2019 at 05:55:25PM +0100, Wolfram Sang wrote:
> From: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>
> i2c_new_dummy is typically called from the probe function of the
> driver for the primary i2c client. It requires calls to
> i2c_unregister_device in the error path of the probe function and
> in the remove function.
> This can be simplified by introducing a device-managed version.
>
> Note the changed error case return value type:
> i2c_new_dummy returns NULL whilst devm_new_i2c_dummy returns an ERR_PTR.
>
> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
> [wsa: rename new functions to 'errptr' style and fix minor kdoc issues]
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> ---
> Documentation/driver-model/devres.txt | 3 +++
> drivers/i2c/i2c-core-base.c | 44 +++++++++++++++++++++++++++++++++++
> include/linux/i2c.h | 3 +++
> 3 files changed, 50 insertions(+)
>
> diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
> index b277cafce71e..e36dc8041857 100644
> --- a/Documentation/driver-model/devres.txt
> +++ b/Documentation/driver-model/devres.txt
> @@ -266,6 +266,9 @@ GPIO
> devm_gpio_request_one()
> devm_gpio_free()
>
> +I2C
> + devm_i2c_new_dummy_errptr()
> +
> IIO
> devm_iio_device_alloc()
> devm_iio_device_free()
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index bbca2e8bb019..7f20c6b8857f 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -921,6 +921,50 @@ struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
> }
> EXPORT_SYMBOL_GPL(i2c_new_dummy);
>
> +struct i2c_dummy_devres {
> + struct i2c_client *client;
> +};
> +
> +static void devm_i2c_release_dummy(struct device *dev, void *res)
> +{
> + struct i2c_dummy_devres *this = res;
> +
> + i2c_unregister_device(this->client);
> +}
> +
> +/**
> + * devm_i2c_new_dummy_errptr - return a new i2c device bound to a dummy driver
> + * @dev: device the managed resource is bound to
> + * @adapter: the adapter managing the device
> + * @address: seven bit address to be used
> + * Context: can sleep
> + *
> + * This is the device-managed version of @i2c_new_dummy. It returns the new i2c
> + * client or an ERR_PTR in case of an error.
> + */
> +struct i2c_client *devm_i2c_new_dummy_errptr(struct device *dev,
> + struct i2c_adapter *adapter,
> + u16 address)
> +{
> + struct i2c_dummy_devres *dr;
> + struct i2c_client *client;
> +
> + dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL);
> + if (!dr)
> + return ERR_PTR(-ENOMEM);
> +
> + client = i2c_new_dummy_errptr(adapter, address);
> + if (IS_ERR(client)) {
> + devres_free(dr);
> + } else {
> + dr->client = client;
> + devres_add(dev, dr);
> + }
> +
> + return client;
> +}
> +EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_errptr);
> +
> /**
> * i2c_new_secondary_device - Helper to get the instantiated secondary address
> * and create the associated device
> diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> index 383510b4f083..93075c2ad9dc 100644
> --- a/include/linux/i2c.h
> +++ b/include/linux/i2c.h
> @@ -470,6 +470,9 @@ extern struct i2c_client *
> i2c_new_dummy(struct i2c_adapter *adap, u16 address);
>
> extern struct i2c_client *
> +devm_i2c_new_dummy_errptr(struct device *dev, struct i2c_adapter *adap, u16 address);
> +
> +extern struct i2c_client *
> i2c_new_secondary_device(struct i2c_client *client,
> const char *name,
> u16 default_addr);
> --
> 2.11.0
>
