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Message-Id: <20221208104006.316606-2-tomi.valkeinen@ideasonboard.com>
Date: Thu, 8 Dec 2022 12:39:59 +0200
From: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
To: linux-media@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-i2c@...r.kernel.org,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Wolfram Sang <wsa@...nel.org>,
Luca Ceresoli <luca.ceresoli@...tlin.com>,
Andy Shevchenko <andriy.shevchenko@...el.com>,
Matti Vaittinen <Matti.Vaittinen@...rohmeurope.com>
Cc: Mauro Carvalho Chehab <mchehab@...nel.org>,
Peter Rosin <peda@...ntia.se>,
Liam Girdwood <lgirdwood@...il.com>,
Mark Brown <broonie@...nel.org>,
Sakari Ailus <sakari.ailus@...ux.intel.com>,
Laurent Pinchart <laurent.pinchart+renesas@...asonboard.com>,
Michael Tretter <m.tretter@...gutronix.de>,
Shawn Tu <shawnx.tu@...el.com>,
Hans Verkuil <hverkuil@...all.nl>,
Mike Pagano <mpagano@...too.org>,
Krzysztof HaĆasa <khalasa@...p.pl>,
Marek Vasut <marex@...x.de>,
Luca Ceresoli <luca@...aceresoli.net>,
Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
Subject: [PATCH v5 1/8] i2c: core: let adapters be notified of client attach/detach
From: Luca Ceresoli <luca@...aceresoli.net>
An adapter might need to know when a new device is about to be
added. This will soon bee needed to implement an "I2C address
translator" (ATR for short), a device that propagates I2C transactions
with a different slave address (an "alias" address). An ATR driver
needs to know when a slave is being added to find a suitable alias and
program the device translation map.
Add an attach/detach callback pair to allow adapter drivers to be
notified of clients being added and removed.
Signed-off-by: Luca Ceresoli <luca@...aceresoli.net>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
---
drivers/i2c/i2c-core-base.c | 18 +++++++++++++++++-
include/linux/i2c.h | 16 ++++++++++++++++
2 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index b4edf10e8fd0..c8bc71b1db82 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -966,15 +966,23 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
}
}
+ if (adap->attach_ops &&
+ adap->attach_ops->attach_client &&
+ adap->attach_ops->attach_client(adap, info, client) != 0)
+ goto out_remove_swnode;
+
status = device_register(&client->dev);
if (status)
- goto out_remove_swnode;
+ goto out_detach_client;
dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
client->name, dev_name(&client->dev));
return client;
+out_detach_client:
+ if (adap->attach_ops && adap->attach_ops->detach_client)
+ adap->attach_ops->detach_client(adap, client);
out_remove_swnode:
device_remove_software_node(&client->dev);
out_err_put_of_node:
@@ -996,9 +1004,17 @@ EXPORT_SYMBOL_GPL(i2c_new_client_device);
*/
void i2c_unregister_device(struct i2c_client *client)
{
+ struct i2c_adapter *adap;
+
if (IS_ERR_OR_NULL(client))
return;
+ adap = client->adapter;
+
+ if (adap->attach_ops &&
+ adap->attach_ops->detach_client)
+ adap->attach_ops->detach_client(adap, client);
+
if (client->dev.of_node) {
of_node_clear_flag(client->dev.of_node, OF_POPULATED);
of_node_put(client->dev.of_node);
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index f7c49bbdb8a1..9a385b6de388 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -584,6 +584,21 @@ struct i2c_lock_operations {
void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
};
+/**
+ * struct i2c_attach_operations - callbacks to notify client attach/detach
+ * @attach_client: Notify of new client being attached
+ * @detach_client: Notify of new client being detached
+ *
+ * Both ops are optional.
+ */
+struct i2c_attach_operations {
+ int (*attach_client)(struct i2c_adapter *adapter,
+ const struct i2c_board_info *info,
+ const struct i2c_client *client);
+ void (*detach_client)(struct i2c_adapter *adapter,
+ const struct i2c_client *client);
+};
+
/**
* struct i2c_timings - I2C timing information
* @bus_freq_hz: the bus frequency in Hz
@@ -726,6 +741,7 @@ struct i2c_adapter {
/* data fields that are valid for all devices */
const struct i2c_lock_operations *lock_ops;
+ const struct i2c_attach_operations *attach_ops;
struct rt_mutex bus_lock;
struct rt_mutex mux_lock;
--
2.34.1
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