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i2c: replace i2c_new_probed_device with an ERR_PTR variant

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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: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Max Staudt <max@enpas.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Wolfram Sang 2019-11-06 10:50:19 +01:00 committed by Wolfram Sang
parent 1b00ff6159
commit c1d084759c
4 changed files with 37 additions and 18 deletions
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10
Documentation/i2c/instantiating-devices.rst
View file

@ -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)::
@ -139,8 +139,8 @@ 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,
normal_i2c, NULL);
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

8
Documentation/i2c/writing-clients.rst
View file

@ -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.

25
drivers/i2c/i2c-core-base.c
View file

@ -2245,10 +2245,10 @@ 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,
struct i2c_board_info *info,
unsigned short const *addr_list,
int (*probe)(struct i2c_adapter *adap, unsigned short addr))
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))
{
int i;
@ -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);

12
include/linux/i2c.h
View file

@ -452,10 +452,16 @@ 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,
int (*probe)(struct i2c_adapter *adap, unsigned short addr));
struct i2c_board_info *info,
unsigned short const *addr_list,
int (*probe)(struct i2c_adapter *adap, unsigned short addr));
/* Common custom probe functions */
extern int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);