diff options
| -rw-r--r-- | drivers/spi/spi.c | 54 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 2 |
2 files changed, 55 insertions, 1 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 6ed2959ce4dc..ed87f71a428d 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1720,6 +1720,46 @@ struct spi_master *spi_alloc_master(struct device *dev, unsigned size) } EXPORT_SYMBOL_GPL(spi_alloc_master); +static void devm_spi_release_master(struct device *dev, void *master) +{ + spi_master_put(*(struct spi_master **)master); +} + +/** + * devm_spi_alloc_master - resource-managed spi_alloc_master() + * @dev: physical device of SPI master + * @size: how much zeroed driver-private data to allocate + * Context: can sleep + * + * Allocate an SPI master and automatically release a reference on it + * when @dev is unbound from its driver. Drivers are thus relieved from + * having to call spi_master_put(). + * + * The arguments to this function are identical to spi_alloc_master(). + * + * Return: the SPI master structure on success, else NULL. + */ +struct spi_master *devm_spi_alloc_master(struct device *dev, unsigned int size) +{ + struct spi_master **ptr, *master; + + ptr = devres_alloc(devm_spi_release_master, sizeof(*ptr), + GFP_KERNEL); + if (!ptr) + return NULL; + + master = spi_alloc_master(dev, size); + if (master) { + *ptr = master; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return master; +} +EXPORT_SYMBOL_GPL(devm_spi_alloc_master); + #ifdef CONFIG_OF static int of_spi_register_master(struct spi_master *master) { @@ -1899,6 +1939,11 @@ int devm_spi_register_master(struct device *dev, struct spi_master *master) } EXPORT_SYMBOL_GPL(devm_spi_register_master); +static int devm_spi_match_master(struct device *dev, void *res, void *master) +{ + return *(struct spi_master **)res == master; +} + static int __unregister(struct device *dev, void *null) { spi_unregister_device(to_spi_device(dev)); @@ -1928,7 +1973,14 @@ void spi_unregister_master(struct spi_master *master) list_del(&master->list); mutex_unlock(&board_lock); - device_unregister(&master->dev); + device_del(&master->dev); + + /* Release the last reference on the master if its driver + * has not yet been converted to devm_spi_alloc_master(). + */ + if (!devres_find(master->dev.parent, devm_spi_release_master, + devm_spi_match_master, master)) + put_device(&master->dev); } EXPORT_SYMBOL_GPL(spi_unregister_master); diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index cce80e6dc7d1..f5d387140c46 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -568,6 +568,8 @@ extern void spi_finalize_current_transfer(struct spi_master *master); /* the spi driver core manages memory for the spi_master classdev */ extern struct spi_master * spi_alloc_master(struct device *host, unsigned size); +extern struct spi_master * +devm_spi_alloc_master(struct device *dev, unsigned int size); extern int spi_register_master(struct spi_master *master); extern int devm_spi_register_master(struct device *dev, |