On 11/20/2014 05:53 PM, Grant Likely wrote:
On Tue, 28 Oct 2014 22:36:03 +0200
, Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
wrote:
Add OF notifier handler needed for creating/destroying i2c devices
according to dynamic runtime changes in the DT live tree.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
---
drivers/i2c/i2c-core.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 78 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index e6da9d3..e751b78 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1470,6 +1470,7 @@ struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
return i2c_verify_adapter(dev);
}
EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
+
#else
static void of_i2c_register_devices(struct i2c_adapter *adap) { }
#endif /* CONFIG_OF */
@@ -1955,6 +1956,71 @@ void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
}
EXPORT_SYMBOL(i2c_clients_command);
+#if IS_ENABLED(CONFIG_OF)
+
+static int of_i2c_notify(struct notifier_block *nb,
+ unsigned long action, void *arg)
+{
+ struct device_node *dn;
+ struct i2c_adapter *adap;
+ struct i2c_client *client;
+ int state;
+
+ state = of_reconfig_get_state_change(action, arg);
+ if (state == -1)
+ return NOTIFY_OK;
+
+ switch (action) {
+ case OF_RECONFIG_ATTACH_NODE:
+ case OF_RECONFIG_DETACH_NODE:
+ dn = arg;
+ break;
+ case OF_RECONFIG_ADD_PROPERTY:
+ case OF_RECONFIG_REMOVE_PROPERTY:
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ dn = ((struct of_prop_reconfig *)arg)->dn;
+ break;
+ default:
+ return NOTIFY_OK;
+ }
+
+ if (state) {
+
+ adap = of_find_i2c_adapter_by_node(dn->parent);
+ if (adap == NULL)
+ return NOTIFY_OK; /* not for us */
+
+ client = of_i2c_register_device(adap, dn);
+ put_device(&adap->dev);
+
+ if (IS_ERR(client)) {
+ pr_err("%s: failed to create for '%s'\n",
+ __func__, dn->full_name);
+ return notifier_from_errno(PTR_ERR(client));
+ }
+
+ } else {
+
+ /* find our device by node */
+ client = of_find_i2c_device_by_node(dn);
+ if (client == NULL)
+ return NOTIFY_OK; /* no? not meant for us */
+
+ /* unregister takes one ref away */
+ i2c_unregister_device(client);
+
+ /* and put the reference of the find */
+ put_device(&client->dev);
+
+ }
Nit: odd whitespace
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block i2c_of_notifier;
+
+#endif
+
static int __init i2c_init(void)
{
int retval;
@@ -1972,8 +2038,19 @@ static int __init i2c_init(void)
retval = i2c_add_driver(&dummy_driver);
if (retval)
goto class_err;
- return 0;
+#if IS_ENABLED(CONFIG_OF)
+ i2c_of_notifier.notifier_call = of_i2c_notify;
Wouldn't it be easier to just initialize i2c_of_notifier above instead of
here in the code ? Or is there a reason for doing it here ?
Thanks,
Guenter
+ retval = of_reconfig_notifier_register(&i2c_of_notifier);
+ if (retval)
+ goto notifier_err;
+#endif
+
+ return 0;
+#if IS_ENABLED(CONFIG_OF)
+notifier_err:
+ i2c_del_driver(&dummy_driver);
+#endif
Similar to my comment on the platform bus, don't break the entire bus if
registration of the notifier fails. I would drop the error case and just
do a WARN_ON() if it fails.
Otherwise:
Acked-by: Grant Likely <grant.likely@xxxxxxxxxx>
class_err:
#ifdef CONFIG_I2C_COMPAT
class_compat_unregister(i2c_adapter_compat_class);
--
1.7.12
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