diff options
Diffstat (limited to 'drivers/i2c/i2c-core.h')
| -rw-r--r-- | drivers/i2c/i2c-core.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h index 37576f50fe20..c88cfef81343 100644 --- a/drivers/i2c/i2c-core.h +++ b/drivers/i2c/i2c-core.h @@ -29,6 +29,42 @@ extern int __i2c_first_dynamic_bus_num; int i2c_check_7bit_addr_validity_strict(unsigned short addr); +/* + * We only allow atomic transfers for very late communication, e.g. to send + * the powerdown command to a PMIC. Atomic transfers are a corner case and not + * for generic use! + */ +static inline bool i2c_in_atomic_xfer_mode(void) +{ + return system_state > SYSTEM_RUNNING && irqs_disabled(); +} + +static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap) +{ + int ret = 0; + + if (i2c_in_atomic_xfer_mode()) { + WARN(!adap->algo->master_xfer_atomic && !adap->algo->smbus_xfer_atomic, + "No atomic I2C transfer handler for '%s'\n", dev_name(&adap->dev)); + ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN; + } else { + i2c_lock_bus(adap, I2C_LOCK_SEGMENT); + } + + return ret; +} + +static inline int __i2c_check_suspended(struct i2c_adapter *adap) +{ + if (test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)) { + if (!test_and_set_bit(I2C_ALF_SUSPEND_REPORTED, &adap->locked_flags)) + dev_WARN(&adap->dev, "Transfer while suspended\n"); + return -ESHUTDOWN; + } + + return 0; +} + #ifdef CONFIG_ACPI const struct acpi_device_id * i2c_acpi_match_device(const struct acpi_device_id *matches, |