SMBus Host Notify allows a slave device to act as a master on a bus to notify the host of an interrupt. The functionality is directly implemented in the firmware so we just export a toggle function and rely on the adapter to actually support this.
Signed-off-by: Benjamin Tissoires <[email protected]> --- Documentation/i2c/smbus-protocol | 4 ++++ drivers/i2c/i2c-core.c | 26 ++++++++++++++++++++++++++ include/linux/i2c.h | 8 ++++++++ include/uapi/linux/i2c.h | 1 + 4 files changed, 39 insertions(+) diff --git a/Documentation/i2c/smbus-protocol b/Documentation/i2c/smbus-protocol index 6012b12..af4e4b9 100644 --- a/Documentation/i2c/smbus-protocol +++ b/Documentation/i2c/smbus-protocol @@ -199,6 +199,10 @@ alerting device's address. [S] [HostAddr] [Wr] A [DevAddr] A [DataLow] A [DataHigh] A [P] +I2C drivers for devices which can trigger SMBus Host Notify should call +i2c_smbus_toggle_host_notify() to enable SMBUS Host Notify on the adapter +and implement the optional alert() callback. + Packet Error Checking (PEC) =========================== diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 987c124..eaaf5b0 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -2959,6 +2959,32 @@ int i2c_slave_unregister(struct i2c_client *client) EXPORT_SYMBOL_GPL(i2c_slave_unregister); #endif +int i2c_smbus_toggle_host_notify(struct i2c_client *client, bool state) +{ + int ret; + + if (!client) + return -EINVAL; + + if (!(client->flags & I2C_CLIENT_TEN)) { + /* Enforce stricter address checking */ + ret = i2c_check_addr_validity(client->addr); + if (ret) + return ret; + } + + if (!client->adapter->algo->toggle_smbus_host_notify) + return -EOPNOTSUPP; + + i2c_lock_adapter(client->adapter); + ret = client->adapter->algo->toggle_smbus_host_notify(client->adapter, + state); + i2c_unlock_adapter(client->adapter); + + return ret; +} +EXPORT_SYMBOL_GPL(i2c_smbus_toggle_host_notify); + MODULE_AUTHOR("Simon G. Vogl <[email protected]>"); MODULE_DESCRIPTION("I2C-Bus main module"); MODULE_LICENSE("GPL"); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index e83a738..7ffc970 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -177,6 +177,8 @@ struct i2c_driver { * The format and meaning of the data value depends on the protocol. * For the SMBus alert protocol, there is a single bit of data passed * as the alert response's low bit ("event flag"). + * For the SMBus Host Notify protocol, the data corresponds to the + * 16-bits payload data reported by the external device. */ void (*alert)(struct i2c_client *, unsigned int data); @@ -270,6 +272,9 @@ static inline int i2c_slave_event(struct i2c_client *client, } #endif + +extern int i2c_smbus_toggle_host_notify(struct i2c_client *client, bool state); + /** * struct i2c_board_info - template for device creation * @type: chip type, to initialize i2c_client.name @@ -378,6 +383,8 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info, * 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 + * @toggle_smbus_host_notify: toggle the SMBus Host Notify support 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 @@ -408,6 +415,7 @@ struct i2c_algorithm { int (*reg_slave)(struct i2c_client *client); int (*unreg_slave)(struct i2c_client *client); #endif + int (*toggle_smbus_host_notify)(struct i2c_adapter *adap, bool state); }; /** diff --git a/include/uapi/linux/i2c.h b/include/uapi/linux/i2c.h index 0e949cb..c72708e 100644 --- a/include/uapi/linux/i2c.h +++ b/include/uapi/linux/i2c.h @@ -100,6 +100,7 @@ struct i2c_msg { #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */ #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */ +#define I2C_FUNC_SMBUS_HOST_NOTIFY 0x10000000 #define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \ I2C_FUNC_SMBUS_WRITE_BYTE) -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
