From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH v8 6/8] OF: i2c: Add OF notifier handler Date: Thu, 20 Nov 2014 18:03:33 -0800 Message-ID: <546E9D75.3000208@roeck-us.net> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20141121015335.99BF2C413E8@trevor.secretlab.ca> Sender: linux-kernel-owner@vger.kernel.org To: Grant Likely , Pantelis Antoniou 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@vger.kernel.org, Wolfram Sang , linux-i2c@vger.kernel.org, Mark Brown , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, Pete List-Id: devicetree@vger.kernel.org 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 ? Thanks, Guenter >> + 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 >> > >