diff options
Diffstat (limited to 'include/linux/i2c.h')
| -rw-r--r-- | include/linux/i2c.h | 48 |
1 files changed, 38 insertions, 10 deletions
diff --git a/include/linux/i2c.h b/include/linux/i2c.h index fb9af6a0fe9..08be0d21864 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -35,6 +35,8 @@ #include <linux/sched.h> /* for completion */ #include <linux/mutex.h> +extern struct bus_type i2c_bus_type; + /* --- General options ------------------------------------------------ */ struct i2c_msg; @@ -43,6 +45,7 @@ struct i2c_adapter; struct i2c_client; struct i2c_driver; union i2c_smbus_data; +struct i2c_board_info; /* * The master routines are the ones normally used to transmit data to devices @@ -69,9 +72,8 @@ extern s32 i2c_smbus_xfer (struct i2c_adapter * adapter, u16 addr, union i2c_smbus_data * data); /* Now follow the 'nice' access routines. These also document the calling - conventions of smbus_access. */ + conventions of i2c_smbus_xfer. */ -extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value); extern s32 i2c_smbus_read_byte(struct i2c_client * client); extern s32 i2c_smbus_write_byte(struct i2c_client * client, u8 value); extern s32 i2c_smbus_read_byte_data(struct i2c_client * client, u8 command); @@ -93,15 +95,33 @@ extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client * client, u8 command, u8 length, const u8 *values); -/* - * A driver is capable of handling one or more physical devices present on - * I2C adapters. This information is used to inform the driver of adapter - * events. +/** + * struct i2c_driver - represent an I2C device driver + * @class: What kind of i2c device we instantiate (for detect) + * @detect: Callback for device detection + * @address_data: The I2C addresses to probe, ignore or force (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. * The driver.name field should be set to the name of this driver. + * + * For automatic device detection, both @detect and @address_data must + * be defined. @class should also be set, otherwise only devices forced + * with module parameters will be created. The detect function must + * fill at least the name field of the i2c_board_info structure it is + * handed upon successful detection, and possibly also the flags field. + * + * If @detect is missing, the driver will still work fine for enumerated + * devices. Detected devices simply won't be supported. This is expected + * for the many I2C/SMBus devices which can't be detected reliably, and + * the ones which can always be enumerated in practice. + * + * The i2c_client structure which is handed to the @detect callback is + * not a real i2c_client. It is initialized just enough so that you can + * call i2c_smbus_read_byte_data and friends on it. Don't do anything + * else with it. In particular, calling dev_dbg and friends on it is + * not allowed. */ - struct i2c_driver { int id; unsigned int class; @@ -141,6 +161,11 @@ struct i2c_driver { struct device_driver driver; const struct i2c_device_id *id_table; + + /* Device detection callback for automatic device creation */ + int (*detect)(struct i2c_client *, int kind, struct i2c_board_info *); + const struct i2c_client_address_data *address_data; + struct list_head clients; }; #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) @@ -156,6 +181,7 @@ struct i2c_driver { * @dev: Driver model device node for the slave. * @irq: indicates the IRQ generated by this device (if any) * @list: list of active/busy clients (DEPRECATED) + * @detected: member of an i2c_driver.clients list * @released: used to synchronize client releases & detaches and references * * An i2c_client identifies a single device (i.e. chip) connected to an @@ -171,8 +197,9 @@ struct i2c_client { struct i2c_adapter *adapter; /* the adapter we sit on */ struct i2c_driver *driver; /* and our access routines */ struct device dev; /* the device structure */ - int irq; /* irq issued by device (or -1) */ + int irq; /* irq issued by device */ struct list_head list; /* DEPRECATED */ + struct list_head detected; struct completion released; }; #define to_i2c_client(d) container_of(d, struct i2c_client, dev) @@ -350,10 +377,11 @@ static inline void i2c_set_adapdata (struct i2c_adapter *dev, void *data) #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ #define I2C_CLASS_TV_ANALOG (1<<1) /* bttv + friends */ #define I2C_CLASS_TV_DIGITAL (1<<2) /* dvb cards */ -#define I2C_CLASS_DDC (1<<3) /* i2c-matroxfb ? */ +#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ #define I2C_CLASS_CAM_ANALOG (1<<4) /* camera with analog CCD */ #define I2C_CLASS_CAM_DIGITAL (1<<5) /* most webcams */ #define I2C_CLASS_SOUND (1<<6) /* sound devices */ +#define I2C_CLASS_SPD (1<<7) /* SPD EEPROMs and similar */ #define I2C_CLASS_ALL (UINT_MAX) /* all of the above */ /* i2c_client_address_data is the struct for holding default client @@ -537,7 +565,7 @@ union i2c_smbus_data { /* and one more for user-space compatibility */ }; -/* smbus_access read or write markers */ +/* i2c_smbus_xfer read or write markers */ #define I2C_SMBUS_READ 1 #define I2C_SMBUS_WRITE 0 |