Hi!
On 2017-08-21 20:24, Heiner Kallweit wrote:
> 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.
>
> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
> ---
> drivers/i2c/i2c-core-base.c | 29 +++++++++++++++++++++++++++++
> include/linux/i2c.h | 3 +++
> 2 files changed, 32 insertions(+)
You need to update Documentation/driver-model/devres.txt
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index 12822a4b..7eb48328 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -868,6 +868,35 @@ struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
> }
> EXPORT_SYMBOL_GPL(i2c_new_dummy);
>
> +static void devm_i2c_release_dummy(struct device *dev, void *res)
> +{
> + i2c_unregister_device(*(struct i2c_client **)res);
> +}
> +
> +/* managed version of i2c_new_dummy */
A kernel-doc comment is preferred for public functions. Especially new
functions...
> +struct i2c_client *devm_i2c_new_dummy(struct device *dev,
> + struct i2c_adapter *adapter,
> + u16 address)
> +{
> + struct i2c_client *ret, **dr;
> +
> + dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL);
> + if (!dr)
> + return NULL;
Would it not be splendid if you returned an error pointer
instead, preferably you should also change the i2c_new_dummy
interface (don't forget to update callers) to return such a
thing instead of NULL on error so that -EBUSY etc is
propagated? But there are a few dozen callers, I don't know
if it's worth it at this point?
Anyway, if we do it right for the managed function from the
start, that count of i2c_new_dummy callers might get more
manageable in the future?
Cheers,
peda
> +
> + ret = i2c_new_dummy(adapter, address);
> + if (!ret) {
> + devres_free(dr);
> + return NULL;
> + }
> +
> + *dr = ret;
> + devres_add(dev, dr);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(devm_i2c_new_dummy);
> +
> /**
> * 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 d501d395..d0c091e6 100644
> --- a/include/linux/i2c.h
> +++ b/include/linux/i2c.h
> @@ -381,6 +381,9 @@ extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
> extern struct i2c_client *
> i2c_new_dummy(struct i2c_adapter *adap, u16 address);
>
> +extern struct i2c_client *
> +devm_i2c_new_dummy(struct device *dev, struct i2c_adapter *adap, u16 address);
> +
> extern struct i2c_client *
> i2c_new_secondary_device(struct i2c_client *client,
> const char *name,
>
