Linux-Renesas-SoC Archive on lore.kernel.org
 help / color / Atom feed
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-i2c@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Bartosz Golaszewski <brgl@bgdev.pl>,
	Kieran Bingham <kieran@ksquared.org.uk>,
	Peter Rosin <peda@axentia.se>,
	Wolfram Sang <wsa+renesas@sang-engineering.com>
Subject: [PATCH v8 2/3] i2c: core: add device-managed version of i2c_new_dummy
Date: Thu, 16 May 2019 23:13:09 +0200
Message-ID: <20190516211310.22277-3-wsa+renesas@sang-engineering.com> (raw)
In-Reply-To: <20190516211310.22277-1-wsa+renesas@sang-engineering.com>

From: Heiner Kallweit <hkallweit1@gmail.com>

i2c_new_dummy is typically called from the probe function of the
driver for the primary i2c client. It requires calls to
i2c_unregister_device in the error path of the probe function and
in the remove function.
This can be simplified by introducing a device-managed version.

Note the changed error case return value type: i2c_new_dummy returns
NULL whilst devm_i2c_new_dummy_device returns an ERR_PTR.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
[wsa: rename new functions and fix minor kdoc issues]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 Documentation/driver-model/devres.txt |  3 ++
 drivers/i2c/i2c-core-base.c           | 44 +++++++++++++++++++++++++++
 include/linux/i2c.h                   |  3 ++
 3 files changed, 50 insertions(+)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 99994a461359..69c7fa7f616c 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -271,6 +271,9 @@ GPIO
   devm_gpio_request_one()
   devm_gpio_free()
 
+I2C
+  devm_i2c_new_dummy_device()
+
 IIO
   devm_iio_device_alloc()
   devm_iio_device_free()
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 9c38dde73366..d389d4fb0623 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -929,6 +929,50 @@ struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
 }
 EXPORT_SYMBOL_GPL(i2c_new_dummy);
 
+struct i2c_dummy_devres {
+	struct i2c_client *client;
+};
+
+static void devm_i2c_release_dummy(struct device *dev, void *res)
+{
+	struct i2c_dummy_devres *this = res;
+
+	i2c_unregister_device(this->client);
+}
+
+/**
+ * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver
+ * @dev: device the managed resource is bound to
+ * @adapter: the adapter managing the device
+ * @address: seven bit address to be used
+ * Context: can sleep
+ *
+ * This is the device-managed version of @i2c_new_dummy_device. It returns the
+ * new i2c client or an ERR_PTR in case of an error.
+ */
+struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,
+					     struct i2c_adapter *adapter,
+					     u16 address)
+{
+	struct i2c_dummy_devres *dr;
+	struct i2c_client *client;
+
+	dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return ERR_PTR(-ENOMEM);
+
+	client = i2c_new_dummy_device(adapter, address);
+	if (IS_ERR(client)) {
+		devres_free(dr);
+	} else {
+		dr->client = client;
+		devres_add(dev, dr);
+	}
+
+	return client;
+}
+EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
+
 /**
  * i2c_new_secondary_device - Helper to get the instantiated secondary address
  * and create the associated device
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index be27062f8ed1..6c4db54714f6 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -469,6 +469,9 @@ extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
 extern struct i2c_client *
 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
 
+extern struct i2c_client *
+devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
+
 extern struct i2c_client *
 i2c_new_secondary_device(struct i2c_client *client,
 				const char *name,
-- 
2.19.1


  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-16 21:13 [PATCH v8 0/3] i2c: improve i2c_new_{device|dummy} Wolfram Sang
2019-05-16 21:13 ` [PATCH v8 1/3] i2c: core: improve return value handling of i2c_new_device and i2c_new_dummy Wolfram Sang
2019-05-17  7:16   ` Peter Rosin
2019-05-17 17:35     ` Wolfram Sang
2019-05-17  8:02   ` Kieran Bingham
2019-05-17  8:56   ` Bartosz Golaszewski
2019-05-17 17:35   ` Wolfram Sang
2019-05-16 21:13 ` Wolfram Sang [this message]
2019-05-17  7:17   ` [PATCH v8 2/3] i2c: core: add device-managed version of i2c_new_dummy Peter Rosin
2019-05-17  8:21   ` Kieran Bingham
2019-05-17  8:57   ` Bartosz Golaszewski
2019-05-17 17:35   ` Wolfram Sang
2019-05-16 21:13 ` [PATCH v8 3/3] mfd: da9063: occupy second I2C address, too Wolfram Sang
2019-05-17  7:17   ` Peter Rosin
2019-05-17  8:57   ` Bartosz Golaszewski
2019-05-17 14:56   ` Kieran Bingham

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190516211310.22277-3-wsa+renesas@sang-engineering.com \
    --to=wsa+renesas@sang-engineering.com \
    --cc=brgl@bgdev.pl \
    --cc=hkallweit1@gmail.com \
    --cc=kieran@ksquared.org.uk \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-renesas-soc@vger.kernel.org \
    --cc=peda@axentia.se \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Renesas-SoC Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-renesas-soc/0 linux-renesas-soc/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-renesas-soc linux-renesas-soc/ https://lore.kernel.org/linux-renesas-soc \
		linux-renesas-soc@vger.kernel.org linux-renesas-soc@archiver.kernel.org
	public-inbox-index linux-renesas-soc


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-renesas-soc


AGPL code for this site: git clone https://public-inbox.org/ public-inbox