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author | Pantelis Antoniou <pantelis.antoniou@konsulko.com> | 2014-10-28 22:36:03 +0200 |
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committer | Grant Likely <grant.likely@linaro.org> | 2014-11-25 15:35:35 +0000 |
commit | ea7513bbc04170f1cbf42953187a4d8b731c71c4 (patch) | |
tree | eae2d5fe9a96b50e45c447249b82f55983df8094 /drivers/i2c/i2c-core.c | |
parent | a430a3455f2c48995e06b359a82a1109a419e9ef (diff) | |
download | op-kernel-dev-ea7513bbc04170f1cbf42953187a4d8b731c71c4.zip op-kernel-dev-ea7513bbc04170f1cbf42953187a4d8b731c71c4.tar.gz |
i2c/of: Add OF_RECONFIG notifier handler
CONFIG_OF_DYNAMIC enables runtime changes to the device tree which in
turn may trigger addition or removal of devices from Linux. Add an
OF_RECONFIG notifier handler to receive tree change events and to
creating or destroy i2c devices as required.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
[grant.likely: clean up #ifdefs and drop unneeded error handling]
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-i2c@vger.kernel.org
Diffstat (limited to 'drivers/i2c/i2c-core.c')
-rw-r--r-- | drivers/i2c/i2c-core.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 15ba618..d8afd3f 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1951,6 +1951,52 @@ void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) } EXPORT_SYMBOL(i2c_clients_command); +#if IS_ENABLED(CONFIG_OF_DYNAMIC) +static int of_i2c_notify(struct notifier_block *nb, unsigned long action, + void *arg) +{ + struct of_reconfig_data *rd = arg; + struct i2c_adapter *adap; + struct i2c_client *client; + + switch (of_reconfig_get_state_change(action, rd)) { + case OF_RECONFIG_CHANGE_ADD: + adap = of_find_i2c_adapter_by_node(rd->dn->parent); + if (adap == NULL) + return NOTIFY_OK; /* not for us */ + + client = of_i2c_register_device(adap, rd->dn); + put_device(&adap->dev); + + if (IS_ERR(client)) { + pr_err("%s: failed to create for '%s'\n", + __func__, rd->dn->full_name); + return notifier_from_errno(PTR_ERR(client)); + } + break; + case OF_RECONFIG_CHANGE_REMOVE: + /* find our device by node */ + client = of_find_i2c_device_by_node(rd->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); + break; + } + + return NOTIFY_OK; +} +static struct notifier_block i2c_of_notifier = { + .notifier_call = of_i2c_notify, +}; +#else +extern struct notifier_block i2c_of_notifier; +#endif /* CONFIG_OF_DYNAMIC */ + static int __init i2c_init(void) { int retval; @@ -1968,6 +2014,10 @@ static int __init i2c_init(void) retval = i2c_add_driver(&dummy_driver); if (retval) goto class_err; + + if (IS_ENABLED(CONFIG_OF_DYNAMIC)) + WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); + return 0; class_err: @@ -1981,6 +2031,8 @@ bus_err: static void __exit i2c_exit(void) { + if (IS_ENABLED(CONFIG_OF_DYNAMIC)) + WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); i2c_del_driver(&dummy_driver); #ifdef CONFIG_I2C_COMPAT class_compat_unregister(i2c_adapter_compat_class); |