Commit c1d08475 authored by Wolfram Sang's avatar Wolfram Sang Committed by Wolfram Sang
Browse files

i2c: replace i2c_new_probed_device with an ERR_PTR variant 



In the general move to have i2c_new_*_device functions which return
ERR_PTR instead of NULL, this patch converts i2c_new_probed_device().

There are only few users, so this patch converts the I2C core and all
users in one go. The function gets renamed to i2c_new_scanned_device()
so out-of-tree users will get a build failure to understand they need to
adapt their error checking code.

Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: default avatarLuca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: default avatarMax Staudt <max@enpas.org>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 1b00ff61

Documentation/i2c/instantiating-devices.rst

+5 −5
Original line number Diff line number Diff line
@@ -123,7 +123,7 @@ present or not (for example for an optional feature which is not present 
on cheap variants of a board but you have no way to tell them apart), or

it may have different addresses from one board to the next (manufacturer

changing its design without notice). In this case, you can call

i2c_new_probed_device() instead of i2c_new_device().

i2c_new_scanned_device() instead of i2c_new_device().



Example (from the nxp OHCI driver)::
@@ -139,7 +139,7 @@ Example (from the nxp OHCI driver):: 
	i2c_adap = i2c_get_adapter(2);

	memset(&i2c_info, 0, sizeof(struct i2c_board_info));

	strscpy(i2c_info.type, "isp1301_nxp", sizeof(i2c_info.type));

	isp1301_i2c_client = i2c_new_probed_device(i2c_adap, &i2c_info,

	isp1301_i2c_client = i2c_new_scanned_device(i2c_adap, &i2c_info,

						    normal_i2c, NULL);

	i2c_put_adapter(i2c_adap);

	(...)
@@ -153,14 +153,14 @@ simply gives up. 
The driver which instantiated the I2C device is responsible for destroying

it on cleanup. This is done by calling i2c_unregister_device() on the

pointer that was earlier returned by i2c_new_device() or

i2c_new_probed_device().

i2c_new_scanned_device().





Method 3: Probe an I2C bus for certain devices

----------------------------------------------



Sometimes you do not have enough information about an I2C device, not even

to call i2c_new_probed_device(). The typical case is hardware monitoring

to call i2c_new_scanned_device(). The typical case is hardware monitoring

chips on PC mainboards. There are several dozen models, which can live

at 25 different addresses. Given the huge number of mainboards out there,

it is next to impossible to build an exhaustive list of the hardware

Documentation/i2c/writing-clients.rst

+4 −4
Original line number Diff line number Diff line
@@ -185,14 +185,14 @@ Sometimes you know that a device is connected to a given I2C bus, but you 
don't know the exact address it uses.  This happens on TV adapters for

example, where the same driver supports dozens of slightly different

models, and I2C device addresses change from one model to the next.  In

that case, you can use the i2c_new_probed_device() variant, which is

that case, you can use the i2c_new_scanned_device() variant, which is

similar to i2c_new_device(), except that it takes an additional list of

possible I2C addresses to probe.  A device is created for the first

responsive address in the list.  If you expect more than one device to be

present in the address range, simply call i2c_new_probed_device() that

present in the address range, simply call i2c_new_scanned_device() that

many times.



The call to i2c_new_device() or i2c_new_probed_device() typically happens

The call to i2c_new_device() or i2c_new_scanned_device() typically happens

in the I2C bus driver. You may want to save the returned i2c_client

reference for later use.
@@ -237,7 +237,7 @@ Device Deletion 
---------------



Each I2C device which has been created using i2c_new_device() or

i2c_new_probed_device() can be unregistered by calling

i2c_new_scanned_device() can be unregistered by calling

i2c_unregister_device().  If you don't call it explicitly, it will be

called automatically before the underlying I2C bus itself is removed, as a

device can't survive its parent in the device driver model.

drivers/i2c/i2c-core-base.c

+19 −6
Original line number Diff line number Diff line
@@ -2245,7 +2245,7 @@ int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) 
EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);



struct i2c_client *

i2c_new_probed_device(struct i2c_adapter *adap,

i2c_new_scanned_device(struct i2c_adapter *adap,

		       struct i2c_board_info *info,

		       unsigned short const *addr_list,

		       int (*probe)(struct i2c_adapter *adap, unsigned short addr))
@@ -2278,11 +2278,24 @@ i2c_new_probed_device(struct i2c_adapter *adap, 


	if (addr_list[i] == I2C_CLIENT_END) {

		dev_dbg(&adap->dev, "Probing failed, no device found\n");

		return NULL;

		return ERR_PTR(-ENODEV);

	}



	info->addr = addr_list[i];

	return i2c_new_device(adap, info);

	return i2c_new_client_device(adap, info);

}

EXPORT_SYMBOL_GPL(i2c_new_scanned_device);



struct i2c_client *

i2c_new_probed_device(struct i2c_adapter *adap,

		      struct i2c_board_info *info,

		      unsigned short const *addr_list,

		      int (*probe)(struct i2c_adapter *adap, unsigned short addr))

{

	struct i2c_client *client;



	client = i2c_new_scanned_device(adap, info, addr_list, probe);

	return IS_ERR(client) ? NULL : client;

}

EXPORT_SYMBOL_GPL(i2c_new_probed_device);

include/linux/i2c.h

+9 −3
Original line number Diff line number Diff line
@@ -452,6 +452,12 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf 
 * a default probing method is used.

 */

extern struct i2c_client *

i2c_new_scanned_device(struct i2c_adapter *adap,

		       struct i2c_board_info *info,

		       unsigned short const *addr_list,

		       int (*probe)(struct i2c_adapter *adap, unsigned short addr));



extern struct i2c_client *

i2c_new_probed_device(struct i2c_adapter *adap,

		       struct i2c_board_info *info,

		       unsigned short const *addr_list,

CRA Git | Maintained and supported by SUSTech CRA and CCSE