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i2c: Drop probe, ignore and force module parameters

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The legacy probe and force module parameters are obsolete now, the
same can be achieved using the new_device sysfs interface, which is
both more flexible and cheaper (it is implemented by i2c-core rather
than replicated in every driver module.)

The legacy ignore module parameters can be dropped as well. Ignoring
can be done by instantiating a "dummy" device at the problematic
address.

This is the first step of a huge cleanup to i2c-core's i2c_detect
function, i2c.h's I2C_CLIENT_INSMOD* macros, and all drivers that made
use of them.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
Jean Delvare 2009-12-06 17:06:24 +01:00
parent abe38388e5
commit c7b25a9e96
3 changed files with 46 additions and 154 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
Documentation/i2c/old-module-parameters Normal file
View File

@ -0,0 +1,44 @@
I2C device driver binding control from user-space
=================================================
Up to kernel 2.6.32, many i2c drivers used helper macros provided by
<linux/i2c.h> which created standard module parameters to let the user
control how the driver would probe i2c buses and attach to devices. These
parameters were known as "probe" (to let the driver probe for an extra
address), "force" (to forcibly attach the driver to a given device) and
"ignore" (to prevent a driver from probing a given address).
With the conversion of the i2c subsystem to the standard device driver
binding model, it became clear that these per-module parameters were no
longer needed, and that a centralized implementation was possible. The new,
sysfs-based interface is described in the documentation file
"instantiating-devices", section "Method 4: Instantiate from user-space".
Below is a mapping from the old module parameters to the new interface.
Attaching a driver to an I2C device
-----------------------------------
Old method (module parameters):
# modprobe <driver> probe=1,0x2d
# modprobe <driver> force=1,0x2d
# modprobe <driver> force_<device>=1,0x2d
New method (sysfs interface):
# echo <device> 0x2d > /sys/bus/i2c/devices/i2c-1/new_device
Preventing a driver from attaching to an I2C device
---------------------------------------------------
Old method (module parameters):
# modprobe <driver> ignore=1,0x2f
New method (sysfs interface):
# echo dummy 0x2f > /sys/bus/i2c/devices/i2c-1/new_device
# modprobe <driver>
Of course, it is important to instantiate the "dummy" device before loading
the driver. The dummy device will be handled by i2c-core itself, preventing
other drivers from binding to it later on. If there is a real device at the
problematic address, and you want another driver to bind to it, then simply
pass the name of the device in question instead of "dummy".

65
drivers/i2c/i2c-core.c
View File

@ -1259,40 +1259,13 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
return -ENOMEM;
temp_client->adapter = adapter;
/* Force entries are done first, and are not affected by ignore
entries */
if (address_data->forces) {
const unsigned short * const *forces = address_data->forces;
int kind;
for (kind = 0; forces[kind]; kind++) {
for (i = 0; forces[kind][i] != I2C_CLIENT_END;
i += 2) {
if (forces[kind][i] == adap_id
|| forces[kind][i] == ANY_I2C_BUS) {
dev_dbg(&adapter->dev, "found force "
"parameter for adapter %d, "
"addr 0x%02x, kind %d\n",
adap_id, forces[kind][i + 1],
kind);
temp_client->addr = forces[kind][i + 1];
err = i2c_detect_address(temp_client,
kind, driver);
if (err)
goto exit_free;
}
}
}
}
/* Stop here if the classes do not match */
if (!(adapter->class & driver->class))
goto exit_free;
/* Stop here if we can't use SMBUS_QUICK */
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) {
if (address_data->probe[0] == I2C_CLIENT_END
&& address_data->normal_i2c[0] == I2C_CLIENT_END)
if (address_data->normal_i2c[0] == I2C_CLIENT_END)
goto exit_free;
dev_warn(&adapter->dev, "SMBus Quick command not supported, "
@ -1301,43 +1274,7 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
goto exit_free;
}
/* Probe entries are done second, and are not affected by ignore
entries either */
for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) {
if (address_data->probe[i] == adap_id
|| address_data->probe[i] == ANY_I2C_BUS) {
dev_dbg(&adapter->dev, "found probe parameter for "
"adapter %d, addr 0x%02x\n", adap_id,
address_data->probe[i + 1]);
temp_client->addr = address_data->probe[i + 1];
err = i2c_detect_address(temp_client, -1, driver);
if (err)
goto exit_free;
}
}
/* Normal entries are done last, unless shadowed by an ignore entry */
for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) {
int j, ignore;
ignore = 0;
for (j = 0; address_data->ignore[j] != I2C_CLIENT_END;
j += 2) {
if ((address_data->ignore[j] == adap_id ||
address_data->ignore[j] == ANY_I2C_BUS)
&& address_data->ignore[j + 1]
== address_data->normal_i2c[i]) {
dev_dbg(&adapter->dev, "found ignore "
"parameter for adapter %d, "
"addr 0x%02x\n", adap_id,
address_data->ignore[j + 1]);
ignore = 1;
break;
}
}
if (ignore)
continue;
dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
"addr 0x%02x\n", adap_id,
address_data->normal_i2c[i]);

91
include/linux/i2c.h
View File

@ -110,7 +110,7 @@ extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client,
* @driver: Device driver model driver
* @id_table: List of I2C devices supported by this driver
* @detect: Callback for device detection
* @address_data: The I2C addresses to probe, ignore or force (for detect)
* @address_data: The I2C addresses to probe (for detect)
* @clients: List of detected clients we created (for i2c-core use only)
*
* The driver.owner field should be set to the module owner of this driver.
@ -397,9 +397,6 @@ static inline void i2c_unlock_adapter(struct i2c_adapter *adapter)
*/
struct i2c_client_address_data {
const unsigned short *normal_i2c;
const unsigned short *probe;
const unsigned short *ignore;
const unsigned short * const *forces;
};
/* Internal numbers to terminate lists */
@ -613,134 +610,48 @@ union i2c_smbus_data {
module_param_array(var, short, &var##_num, 0); \
MODULE_PARM_DESC(var, desc)
#define I2C_CLIENT_MODULE_PARM_FORCE(name) \
I2C_CLIENT_MODULE_PARM(force_##name, \
"List of adapter,address pairs which are " \
"unquestionably assumed to contain a `" \
# name "' chip")
#define I2C_CLIENT_INSMOD_COMMON \
I2C_CLIENT_MODULE_PARM(probe, "List of adapter,address pairs to scan " \
"additionally"); \
I2C_CLIENT_MODULE_PARM(ignore, "List of adapter,address pairs not to " \
"scan"); \
static const struct i2c_client_address_data addr_data = { \
.normal_i2c = normal_i2c, \
.probe = probe, \
.ignore = ignore, \
.forces = forces, \
}
#define I2C_CLIENT_FORCE_TEXT \
"List of adapter,address pairs to boldly assume to be present"
/* These are the ones you want to use in your own drivers. Pick the one
which matches the number of devices the driver differenciates between. */
#define I2C_CLIENT_INSMOD \
I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \
static const unsigned short * const forces[] = { force, NULL }; \
I2C_CLIENT_INSMOD_COMMON
#define I2C_CLIENT_INSMOD_1(chip1) \
enum chips { any_chip, chip1 }; \
I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \
I2C_CLIENT_MODULE_PARM_FORCE(chip1); \
static const unsigned short * const forces[] = { force, \
force_##chip1, NULL }; \
I2C_CLIENT_INSMOD_COMMON
#define I2C_CLIENT_INSMOD_2(chip1, chip2) \
enum chips { any_chip, chip1, chip2 }; \
I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \
I2C_CLIENT_MODULE_PARM_FORCE(chip1); \
I2C_CLIENT_MODULE_PARM_FORCE(chip2); \
static const unsigned short * const forces[] = { force, \
force_##chip1, force_##chip2, NULL }; \
I2C_CLIENT_INSMOD_COMMON
#define I2C_CLIENT_INSMOD_3(chip1, chip2, chip3) \
enum chips { any_chip, chip1, chip2, chip3 }; \
I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \
I2C_CLIENT_MODULE_PARM_FORCE(chip1); \
I2C_CLIENT_MODULE_PARM_FORCE(chip2); \
I2C_CLIENT_MODULE_PARM_FORCE(chip3); \
static const unsigned short * const forces[] = { force, \
force_##chip1, force_##chip2, force_##chip3, NULL }; \
I2C_CLIENT_INSMOD_COMMON
#define I2C_CLIENT_INSMOD_4(chip1, chip2, chip3, chip4) \
enum chips { any_chip, chip1, chip2, chip3, chip4 }; \
I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \
I2C_CLIENT_MODULE_PARM_FORCE(chip1); \
I2C_CLIENT_MODULE_PARM_FORCE(chip2); \
I2C_CLIENT_MODULE_PARM_FORCE(chip3); \
I2C_CLIENT_MODULE_PARM_FORCE(chip4); \
static const unsigned short * const forces[] = { force, \
force_##chip1, force_##chip2, force_##chip3, \
force_##chip4, NULL}; \
I2C_CLIENT_INSMOD_COMMON
#define I2C_CLIENT_INSMOD_5(chip1, chip2, chip3, chip4, chip5) \
enum chips { any_chip, chip1, chip2, chip3, chip4, chip5 }; \
I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \
I2C_CLIENT_MODULE_PARM_FORCE(chip1); \
I2C_CLIENT_MODULE_PARM_FORCE(chip2); \
I2C_CLIENT_MODULE_PARM_FORCE(chip3); \
I2C_CLIENT_MODULE_PARM_FORCE(chip4); \
I2C_CLIENT_MODULE_PARM_FORCE(chip5); \
static const unsigned short * const forces[] = { force, \
force_##chip1, force_##chip2, force_##chip3, \
force_##chip4, force_##chip5, NULL }; \
I2C_CLIENT_INSMOD_COMMON
#define I2C_CLIENT_INSMOD_6(chip1, chip2, chip3, chip4, chip5, chip6) \
enum chips { any_chip, chip1, chip2, chip3, chip4, chip5, chip6 }; \
I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \
I2C_CLIENT_MODULE_PARM_FORCE(chip1); \
I2C_CLIENT_MODULE_PARM_FORCE(chip2); \
I2C_CLIENT_MODULE_PARM_FORCE(chip3); \
I2C_CLIENT_MODULE_PARM_FORCE(chip4); \
I2C_CLIENT_MODULE_PARM_FORCE(chip5); \
I2C_CLIENT_MODULE_PARM_FORCE(chip6); \
static const unsigned short * const forces[] = { force, \
force_##chip1, force_##chip2, force_##chip3, \
force_##chip4, force_##chip5, force_##chip6, NULL }; \
I2C_CLIENT_INSMOD_COMMON
#define I2C_CLIENT_INSMOD_7(chip1, chip2, chip3, chip4, chip5, chip6, chip7) \
enum chips { any_chip, chip1, chip2, chip3, chip4, chip5, chip6, \
chip7 }; \
I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \
I2C_CLIENT_MODULE_PARM_FORCE(chip1); \
I2C_CLIENT_MODULE_PARM_FORCE(chip2); \
I2C_CLIENT_MODULE_PARM_FORCE(chip3); \
I2C_CLIENT_MODULE_PARM_FORCE(chip4); \
I2C_CLIENT_MODULE_PARM_FORCE(chip5); \
I2C_CLIENT_MODULE_PARM_FORCE(chip6); \
I2C_CLIENT_MODULE_PARM_FORCE(chip7); \
static const unsigned short * const forces[] = { force, \
force_##chip1, force_##chip2, force_##chip3, \
force_##chip4, force_##chip5, force_##chip6, \
force_##chip7, NULL }; \
I2C_CLIENT_INSMOD_COMMON
#define I2C_CLIENT_INSMOD_8(chip1, chip2, chip3, chip4, chip5, chip6, chip7, chip8) \
enum chips { any_chip, chip1, chip2, chip3, chip4, chip5, chip6, \
chip7, chip8 }; \
I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \
I2C_CLIENT_MODULE_PARM_FORCE(chip1); \
I2C_CLIENT_MODULE_PARM_FORCE(chip2); \
I2C_CLIENT_MODULE_PARM_FORCE(chip3); \
I2C_CLIENT_MODULE_PARM_FORCE(chip4); \
I2C_CLIENT_MODULE_PARM_FORCE(chip5); \
I2C_CLIENT_MODULE_PARM_FORCE(chip6); \
I2C_CLIENT_MODULE_PARM_FORCE(chip7); \
I2C_CLIENT_MODULE_PARM_FORCE(chip8); \
static const unsigned short * const forces[] = { force, \
force_##chip1, force_##chip2, force_##chip3, \
force_##chip4, force_##chip5, force_##chip6, \
force_##chip7, force_##chip8, NULL }; \
I2C_CLIENT_INSMOD_COMMON
#endif /* __KERNEL__ */
#endif /* _LINUX_I2C_H */