From 4b1acc43331d6c716c331a61477660dc20c8b59c Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Tue, 18 Nov 2014 17:04:53 +0100 Subject: i2c: core changes for slave support Finally(!), make Linux support being an I2C slave. Most of the existing infrastructure is reused. We mainly add i2c_slave_register/unregister() calls which tells i2c bus drivers to activate the slave mode. Then, they also get a callback to report slave events to. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang --- include/linux/i2c.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'include/linux/i2c.h') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index b556e0ab946f..a720d9921b47 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -46,6 +46,8 @@ struct i2c_client; struct i2c_driver; union i2c_smbus_data; struct i2c_board_info; +enum i2c_slave_event; +typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *); struct module; @@ -209,6 +211,8 @@ struct i2c_driver { * @irq: indicates the IRQ generated by this device (if any) * @detected: member of an i2c_driver.clients list or i2c-core's * userspace_devices list + * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter + * calls it to pass on slave events to the slave driver. * * An i2c_client identifies a single device (i.e. chip) connected to an * i2c bus. The behaviour exposed to Linux is defined by the driver @@ -224,6 +228,7 @@ struct i2c_client { struct device dev; /* the device structure */ int irq; /* irq issued by device */ struct list_head detected; + i2c_slave_cb_t slave_cb; /* callback for slave mode */ }; #define to_i2c_client(d) container_of(d, struct i2c_client, dev) @@ -246,6 +251,25 @@ static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) dev_set_drvdata(&dev->dev, data); } +/* I2C slave support */ + +enum i2c_slave_event { + I2C_SLAVE_REQ_READ_START, + I2C_SLAVE_REQ_READ_END, + I2C_SLAVE_REQ_WRITE_START, + I2C_SLAVE_REQ_WRITE_END, + I2C_SLAVE_STOP, +}; + +extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); +extern int i2c_slave_unregister(struct i2c_client *client); + +static inline int i2c_slave_event(struct i2c_client *client, + enum i2c_slave_event event, u8 *val) +{ + return client->slave_cb(client, event, val); +} + /** * struct i2c_board_info - template for device creation * @type: chip type, to initialize i2c_client.name @@ -352,6 +376,8 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info, * into I2C transfers instead. * @functionality: Return the flags that this algorithm/adapter pair supports * from the I2C_FUNC_* flags. + * @reg_slave: Register given client to I2C slave mode of this adapter + * @unreg_slave: Unregister given client from I2C slave mode of this adapter * * The following structs are for those who like to implement new bus drivers: * i2c_algorithm is the interface to a class of hardware solutions which can @@ -377,6 +403,9 @@ struct i2c_algorithm { /* To determine what the adapter supports */ u32 (*functionality) (struct i2c_adapter *); + + int (*reg_slave)(struct i2c_client *client); + int (*unreg_slave)(struct i2c_client *client); }; /** -- cgit v1.2.3-59-g8ed1b