Re: [PATCH v8 6/8] OF: i2c: Add OF notifier handler

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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




--
To unsubscribe from this list: send the line "unsubscribe linux-spi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]

  Powered by Linux