Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757717AbaKUBxq (ORCPT ); Thu, 20 Nov 2014 20:53:46 -0500 Received: from mail-wi0-f174.google.com ([209.85.212.174]:46581 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756889AbaKUBxo (ORCPT ); Thu, 20 Nov 2014 20:53:44 -0500 From: Grant Likely Subject: Re: [PATCH v8 6/8] OF: i2c: Add OF notifier handler To: Pantelis Antoniou Cc: Rob Herring , Stephen Warren , Matt Porter , Koen Kooi , Greg Kroah-Hartman , Alison Chaiken , Dinh Nguyen , Jan Lubbe , Alexander Sverdlin , Michael Stickel , Guenter Roeck , Dirk Behme , Alan Tull , Sascha Hauer , Michael Bohan , Ionut Nicu , Michal Simek , Matt Ranostay , Joel Becker , devicetree@vger.kernel.org, Wolfram Sang , linux-i2c@vger.kernel.org, Mark Brown , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, Pete Popov , Dan Malek , Georgi Vlaev , Pantelis Antoniou , Pantelis Antoniou In-Reply-To: <1414528565-10907-7-git-send-email-pantelis.antoniou@konsulko.com> References: <1414528565-10907-1-git-send-email-pantelis.antoniou@konsulko.com> <1414528565-10907-7-git-send-email-pantelis.antoniou@konsulko.com> Date: Fri, 21 Nov 2014 01:53:35 +0000 Message-Id: <20141121015335.99BF2C413E8@trevor.secretlab.ca> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 28 Oct 2014 22:36:03 +0200 , Pantelis Antoniou 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 > --- > 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 > 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-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/