From: Luca Ceresoli <luca@lucaceresoli.net>
To: linux-media@vger.kernel.org, linux-i2c@vger.kernel.org
Cc: Luca Ceresoli <luca@lucaceresoli.net>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Wolfram Sang <wsa@the-dreams.de>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
Hans Verkuil <hverkuil-cisco@xs4all.nl>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Kieran Bingham <kieran.bingham@ideasonboard.com>,
Jacopo Mondi <jacopo@jmondi.org>,
Vladimir Zapolskiy <vz@mleia.com>, Peter Rosin <peda@axentia.se>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>,
matti.vaittinen@fi.rohmeurope.com
Subject: [RFCv3 1/6] i2c: core: let adapters be notified of client attach/detach
Date: Sun, 6 Feb 2022 12:59:34 +0100 [thread overview]
Message-ID: <20220206115939.3091265-2-luca@lucaceresoli.net> (raw)
In-Reply-To: <20220206115939.3091265-1-luca@lucaceresoli.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@lucaceresoli.net>
---
Changes RFCv2 -> RFCv3:
- rebase on current master
Changes RFCv1 -> RFCv2:
- Document struct i2c_attach_operations
---
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 2c59dd748a49..aea1e1b552b0 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 7d4f52ceb7b5..aadd71e0533c 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -587,6 +587,21 @@ 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
@@ -729,6 +744,7 @@ 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;
--
2.25.1
next prev parent reply other threads:[~2022-02-06 13:59 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-06 11:59 [RFCv3 0/6] Hi, Luca Ceresoli
2022-02-06 11:59 ` Luca Ceresoli [this message]
2022-02-06 11:59 ` [RFCv3 2/6] i2c: add I2C Address Translator (ATR) support Luca Ceresoli
2022-02-08 11:16 ` Andy Shevchenko
2022-02-16 8:40 ` Luca Ceresoli
2022-02-17 5:12 ` Vaittinen, Matti
2022-03-16 14:11 ` Vaittinen, Matti
2022-03-16 14:25 ` Luca Ceresoli
2022-02-06 11:59 ` [RFCv3 3/6] media: dt-bindings: add DS90UB953-Q1 video serializer Luca Ceresoli
2022-02-07 21:48 ` Rob Herring
2022-02-06 11:59 ` [RFCv3 4/6] media: dt-bindings: add DS90UB954-Q1 video deserializer Luca Ceresoli
2022-02-06 18:46 ` Rob Herring
2022-02-07 19:39 ` Rob Herring
2022-02-06 11:59 ` [RFCv3 5/6] media: ds90ub954: new driver for TI " Luca Ceresoli
2022-02-06 11:59 ` [RFCv3 6/6] media: ds90ub953: new driver for TI DS90UB953-Q1 video serializer Luca Ceresoli
2022-02-06 12:05 ` [RFCv3 0/6] TI camera serdes and I2C address translation Luca Ceresoli
2022-02-07 12:06 ` [RFCv3 0/6] TI camera serdes and I2C address translation (Was: [RFCv3 0/6] Hi,) Tomi Valkeinen
2022-02-07 13:21 ` Vaittinen, Matti
2022-02-07 14:07 ` Luca Ceresoli
2022-02-07 14:38 ` Vaittinen, Matti
2022-02-07 16:23 ` Tomi Valkeinen
2022-02-08 6:40 ` Vaittinen, Matti
2022-02-08 8:28 ` Tomi Valkeinen
2022-02-08 9:36 ` Vaittinen, Matti
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