[PATCH V3 1/2] i2c: core: add devm apis for i2c_new_dummy()

[PATCH V3 1/2] i2c: core: add devm apis for i2c_new_dummy()

[Laxman Dewangan]

Add resource managed version of i2c_new_dummy().

This helps in:
 1. reducing the code size in error path to explicitly unregister
    the new dummy client.
 2. Sometime, need of the remove callback on client driver to just
    unregister the new i2c dummy client.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>

---
Changes from V1:
- Got review comment on similar change for pinctrl and taken care of
 the same on this patch as V1 has similar issue.
- Add the new devm_ APIs in the Documentation/driver-model/devres.txt
- Will push the change for using this new APIs later once this is
  applied as most of consumer for these APIs are in other subsystem like
  MFD/RTC.

Changes from V2:
- Drop devm_i2c_unregister_device() as it is not used in general.
---
 drivers/i2c/i2c-core.c | 41 +++++++++++++++++++++++++++++++++++++++++
 include/linux/i2c.h    |  4 ++++
 2 files changed, 45 insertions(+)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 952d2f0..dc30b9b 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1145,6 +1145,47 @@ struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
 }
 EXPORT_SYMBOL_GPL(i2c_new_dummy);
 
+static void devm_i2c_dummy_release(struct device *dev, void *res)
+{
+	i2c_unregister_device(*(struct i2c_client **)res);
+}
+
+/**
+ * devm_i2c_new_dummy - Resource managed version of i2c_new_dummy().
+ * @dev:	Device handle for which this resouce belongs to.
+ * @adapter:	the adapter managing the device
+ * @address:	seven bit address to be used
+ * Context:	can sleep
+
+ * Please refer the details of i2c_new_dummy() for more information.
+ *
+ * This returns the new i2c client on success; or NULL to indicate an error.
+ * The new i2c_client will be automatically released when the device is unbound.
+ */
+struct i2c_client *devm_i2c_new_dummy(struct device *dev,
+				      struct i2c_adapter *adapter,
+				      u16 address)
+{
+	struct i2c_client **ptr, *i2c_dummy;
+
+	ptr = devres_alloc(devm_i2c_dummy_release, sizeof(*ptr),
+			   GFP_KERNEL);
+	if (!ptr)
+		return NULL;
+
+	i2c_dummy = i2c_new_dummy(adapter, address);
+	if (!i2c_dummy) {
+		devres_free(ptr);
+		return NULL;
+	}
+
+	*ptr = i2c_dummy;
+	devres_add(dev, ptr);
+
+	return i2c_dummy;
+}
+EXPORT_SYMBOL_GPL(devm_i2c_new_dummy);
+
 /**
  * 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 6df7bad..257b239 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -355,6 +355,10 @@ i2c_new_secondary_device(struct i2c_client *client,
 				u16 default_addr);
 
 extern void i2c_unregister_device(struct i2c_client *);
+
+extern struct i2c_client *
+devm_i2c_new_dummy(struct device *dev, struct i2c_adapter *adap, u16 address);
+
 #endif /* I2C */
 
 /* Mainboard arch_initcall() code should register all its I2C devices.
-- 
2.1.4

[PATCH V3 2/2] i2c: Add devm_i2c_new_dummy() in managed list

[Laxman Dewangan]

i2c_new_dummy() gained their devm_ wrappers. Add the
devm_i2c_new_dummy() in managed APIs list.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
Changes form V2:
- Drop the devm_i2c_unregister_device()

 Documentation/driver-model/devres.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index f5e5223..472e446 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -259,6 +259,9 @@ GPIO
   devm_gpio_request_one()
   devm_gpio_free()
 
+I2C
+  devm_i2c_new_dummy()
+
 IIO
   devm_iio_device_alloc()
   devm_iio_device_free()
-- 
2.1.4

Re: [PATCH V3 1/2] i2c: core: add devm apis for i2c_new_dummy()

[kbuild test robot]

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Hi,

[auto build test WARNING on wsa/i2c/for-next]
[also build test WARNING on next-20160617]
[cannot apply to v4.7-rc3]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Laxman-Dewangan/i2c-core-add-devm-apis-for-i2c_new_dummy/20160617-215840
base:   https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux i2c/for-next
reproduce: make htmldocs

All warnings (new ones prefixed by >>):

   include/linux/init.h:1: warning: no structured comments found
   kernel/sched/core.c:2079: warning: No description found for parameter 'cookie'
   kernel/sys.c:1: warning: no structured comments found
   drivers/dma-buf/seqno-fence.c:1: warning: no structured comments found
>> drivers/i2c/i2c-core.c:1159: warning: bad line: 

vim +1159 drivers/i2c/i2c-core.c

  1143	
  1144		return i2c_new_device(adapter, &info);
  1145	}
  1146	EXPORT_SYMBOL_GPL(i2c_new_dummy);
  1147	
  1148	static void devm_i2c_dummy_release(struct device *dev, void *res)
  1149	{
  1150		i2c_unregister_device(*(struct i2c_client **)res);
  1151	}
  1152	
  1153	/**
  1154	 * devm_i2c_new_dummy - Resource managed version of i2c_new_dummy().
  1155	 * @dev:	Device handle for which this resouce belongs to.
  1156	 * @adapter:	the adapter managing the device
  1157	 * @address:	seven bit address to be used
  1158	 * Context:	can sleep
> 1159	
  1160	 * Please refer the details of i2c_new_dummy() for more information.
  1161	 *
  1162	 * This returns the new i2c client on success; or NULL to indicate an error.
  1163	 * The new i2c_client will be automatically released when the device is unbound.
  1164	 */
  1165	struct i2c_client *devm_i2c_new_dummy(struct device *dev,
  1166					      struct i2c_adapter *adapter,
  1167					      u16 address)

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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