On Tue, 28 Oct 2014 22:36:03 +0200
, Pantelis Antoniou <pantelis.anton...@konsulko.com>
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.anton...@konsulko.com>
> ---
> 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;
> + 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.lik...@linaro.org>
> class_err:
> #ifdef CONFIG_I2C_COMPAT
> class_compat_unregister(i2c_adapter_compat_class);
> --
> 1.7.12
>
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