From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH v8 6/8] OF: i2c: Add OF notifier handler Date: Fri, 21 Nov 2014 15:08:37 +0000 Message-ID: <20141121150837.20DC4C40D85@trevor.secretlab.ca> 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> Cc: 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-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Wolfram Sang , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mark Brown , linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Pete Po To: Guenter Roeck , Pantelis Antoniou Return-path: In-Reply-To: <546E9D75.3000208-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: 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. > > 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. 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-u79uwXL29TY76Z2rM5mHXA@public.gmane.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-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html