diff options
Diffstat (limited to 'include/linux/i2c.h')
| -rw-r--r-- | include/linux/i2c.h | 50 |
1 files changed, 48 insertions, 2 deletions
diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 200cf13b00f6..96a25ae14494 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -524,6 +524,7 @@ struct i2c_adapter { /* data fields that are valid for all devices */ struct rt_mutex bus_lock; + struct rt_mutex mux_lock; int timeout; /* in jiffies */ int retries; @@ -538,6 +539,10 @@ struct i2c_adapter { struct i2c_bus_recovery_info *bus_recovery_info; const struct i2c_adapter_quirks *quirks; + + void (*lock_bus)(struct i2c_adapter *, unsigned int flags); + int (*trylock_bus)(struct i2c_adapter *, unsigned int flags); + void (*unlock_bus)(struct i2c_adapter *, unsigned int flags); }; #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) @@ -567,8 +572,44 @@ i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); /* Adapter locking functions, exported for shared pin cases */ -void i2c_lock_adapter(struct i2c_adapter *); -void i2c_unlock_adapter(struct i2c_adapter *); +#define I2C_LOCK_ROOT_ADAPTER BIT(0) +#define I2C_LOCK_SEGMENT BIT(1) + +/** + * i2c_lock_bus - Get exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT + * locks only this branch in the adapter tree + */ +static inline void +i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) +{ + adapter->lock_bus(adapter, flags); +} + +/** + * i2c_unlock_bus - Release exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT + * unlocks only this branch in the adapter tree + */ +static inline void +i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) +{ + adapter->unlock_bus(adapter, flags); +} + +static inline void +i2c_lock_adapter(struct i2c_adapter *adapter) +{ + i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); +} + +static inline void +i2c_unlock_adapter(struct i2c_adapter *adapter) +{ + i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); +} /*flags for the client struct: */ #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ @@ -654,6 +695,11 @@ static inline int i2c_adapter_id(struct i2c_adapter *adap) return adap->nr; } +static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) +{ + return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); +} + /** * module_i2c_driver() - Helper macro for registering a modular I2C driver * @__i2c_driver: i2c_driver struct |