diff options
| -rw-r--r-- | drivers/spi/spi.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index a3557c57d4f7..bf1cab0fad66 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2317,6 +2317,86 @@ EXPORT_SYMBOL_GPL(spi_write_then_read); /*-------------------------------------------------------------------------*/ +#if IS_ENABLED(CONFIG_OF_DYNAMIC) +static int __spi_of_device_match(struct device *dev, void *data) +{ + return dev->of_node == data; +} + +/* must call put_device() when done with returned spi_device device */ +static struct spi_device *of_find_spi_device_by_node(struct device_node *node) +{ + struct device *dev = bus_find_device(&spi_bus_type, NULL, node, + __spi_of_device_match); + return dev ? to_spi_device(dev) : NULL; +} + +static int __spi_of_master_match(struct device *dev, const void *data) +{ + return dev->of_node == data; +} + +/* the spi masters are not using spi_bus, so we find it with another way */ +static struct spi_master *of_find_spi_master_by_node(struct device_node *node) +{ + struct device *dev; + + dev = class_find_device(&spi_master_class, NULL, node, + __spi_of_master_match); + if (!dev) + return NULL; + + /* reference got in class_find_device */ + return container_of(dev, struct spi_master, dev); +} + +static int of_spi_notify(struct notifier_block *nb, unsigned long action, + void *arg) +{ + struct of_reconfig_data *rd = arg; + struct spi_master *master; + struct spi_device *spi; + + switch (of_reconfig_get_state_change(action, arg)) { + case OF_RECONFIG_CHANGE_ADD: + master = of_find_spi_master_by_node(rd->dn->parent); + if (master == NULL) + return NOTIFY_OK; /* not for us */ + + spi = of_register_spi_device(master, rd->dn); + put_device(&master->dev); + + if (IS_ERR(spi)) { + pr_err("%s: failed to create for '%s'\n", + __func__, rd->dn->full_name); + return notifier_from_errno(PTR_ERR(spi)); + } + break; + + case OF_RECONFIG_CHANGE_REMOVE: + /* find our device by node */ + spi = of_find_spi_device_by_node(rd->dn); + if (spi == NULL) + return NOTIFY_OK; /* no? not meant for us */ + + /* unregister takes one ref away */ + spi_unregister_device(spi); + + /* and put the reference of the find */ + put_device(&spi->dev); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block spi_of_notifier = { + .notifier_call = of_spi_notify, +}; +#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ +extern struct notifier_block spi_of_notifier; +#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ + static int __init spi_init(void) { int status; @@ -2334,6 +2414,10 @@ static int __init spi_init(void) status = class_register(&spi_master_class); if (status < 0) goto err2; + + if (IS_ENABLED(CONFIG_OF)) + WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); + return 0; err2: |
