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i2c: Shrink struct i2c_client

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This shrinks the size of "struct i2c_client" by 40 bytes:

 - Substantially shrinks the string used to identify the chip type
 - The "flags" don't need to be so big
 - Removes some internal padding

It also adds kerneldoc for that struct, explaining how "name" is really a
chip type identifier; it's otherwise potentially confusing.

Because the I2C_NAME_SIZE symbol was abused for both i2c_client.name
and for i2c_adapter.name, this needed to affect i2c_adapter too.  The
adapters which used that symbol now use the more-obviously-correct
idiom of taking the size of that field.

JD: Shorten i2c_adapter.name from 50 to 48 bytes while we're here, to
avoid wasting space in padding.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
David Brownell 2007-05-01 23:26:28 +02:00 • committed by Jean Delvare
parent 4ad4eac606
commit 2096b956d2
19 changed files with 34 additions and 27 deletions
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21
include/linux/i2c.h
View file

@ -140,25 +140,30 @@ struct i2c_driver {
};
#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
#define I2C_NAME_SIZE 50
#define I2C_NAME_SIZE 20
/*
* i2c_client identifies a single device (i.e. chip) that is connected to an
* i2c bus. The behaviour is defined by the routines of the driver. This
* function is mainly used for lookup & other admin. functions.
/**
* struct i2c_client - represent an I2C slave device
* @addr: Address used on the I2C bus connected to the parent adapter.
* @name: Indicates the type of the device, usually a chip name that's
* generic enough to hide second-sourcing and compatible revisions.
* @dev: Driver model device node for the slave.
*
* An i2c_client identifies a single device (i.e. chip) connected to an
* i2c bus. The behaviour is defined by the routines of the driver.
*/
struct i2c_client {
unsigned int flags; /* div., see below */
unsigned short flags; /* div., see below */
unsigned short addr; /* chip address - NOTE: 7bit */
/* addresses are stored in the */
/* _LOWER_ 7 bits */
char name[I2C_NAME_SIZE];
struct i2c_adapter *adapter; /* the adapter we sit on */
struct i2c_driver *driver; /* and our access routines */
int usage_count; /* How many accesses currently */
/* to the client */
struct device dev; /* the device structure */
struct list_head list;
char name[I2C_NAME_SIZE];
struct completion released;
};
#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
@ -231,7 +236,7 @@ struct i2c_adapter {
int nr;
struct list_head clients;
struct list_head list;
char name[I2C_NAME_SIZE];
char name[48];
struct completion dev_released;
};
#define dev_to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)