Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758498AbaKUPQ5 (ORCPT ); Fri, 21 Nov 2014 10:16:57 -0500 Received: from mail-wg0-f42.google.com ([74.125.82.42]:47558 "EHLO mail-wg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751596AbaKUPQz convert rfc822-to-8bit (ORCPT ); Fri, 21 Nov 2014 10:16:55 -0500 Subject: Re: [PATCH v8 6/8] OF: i2c: Add OF notifier handler Mime-Version: 1.0 (Mac OS X Mail 8.1 \(1993\)) Content-Type: text/plain; charset=utf-8 From: Pantelis Antoniou In-Reply-To: <20141121150837.20DC4C40D85@trevor.secretlab.ca> Date: Fri, 21 Nov 2014 17:11:15 +0200 Cc: Guenter Roeck , Rob Herring , Stephen Warren , Matt Porter , Koen Kooi , Greg Kroah-Hartman , Alison Chaiken , Dinh Nguyen , Jan Lubbe , Alexander Sverdlin , Michael Stickel , 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 Content-Transfer-Encoding: 8BIT Message-Id: References: <1414528565-10907-1-git-send-email-pantelis.antoniou@konsulko.com> <1414528565-10907-7-git-send-email-pantelis.antoniou@konsulko.com> <20141121015335.99BF2C413E8@trevor.secretlab.ca> <546E9D75.3000208@roeck-us.net> <20141121150837.20DC4C40D85@trevor.secretlab.ca> To: Grant Likely X-Mailer: Apple Mail (2.1993) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Grant, > On Nov 21, 2014, at 17:08 , Grant Likely wrote: > > On Thu, 20 Nov 2014 18:03:33 -0800 > , Guenter Roeck > wrote: >> On 11/20/2014 05:53 PM, Grant Likely wrote: >>> 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; >> >> 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 ? > > Yes, absolutely. This code should also depend on CONFIG_OF_DYNAMIC too, > not merely CONFIG_OF. > >> No reason; it just seemed like the most opportune place to put it at the time. >> Thanks, >> Guenter >> >>>> + retval = of_reconfig_notifier_register(&i2c_of_notifier); >>>> + if (retval) >>>> + goto notifier_err; >>>> +#endif > > We can also get rid of the ugly #ifdef in the body by creating empty > stubs for of_reconfig_notify_{register,unregister}() and doing the > following: > > if (IS_ENABLED(CONFIG_OF_DYNAMIC)) > WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)) > > I picked up the patch into my tree and made the above changes because > they're pretty trivial. If Wolfram is okay with it then I can take the > whole series through my tree. Otherwise I'll put the of_reconfig_* empty > stubs into a separate branch that he and broonie can both pull. > I’m fine with doing this if you’d like, it’s pretty simple. Regards — Pantelis > g. > >>>> + >>>> + 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/ -- 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/