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spi/of: Add OF notifier handler

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Add OF notifier handler needed for creating/destroying spi devices
according to dynamic runtime changes in the DT live tree. This code is
enabled when CONFIG_OF_DYNAMIC is selected.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Cc: <linux-spi@vger.kernel.org>
This commit is contained in:
Pantelis Antoniou 2014-10-28 22:36:05 +02:00 committed by Grant Likely
parent aff5e3f89a
commit ce79d54ae4
1 changed files with 84 additions and 0 deletions
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84
drivers/spi/spi.c
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@ -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: