Line data    Source code

       1             : /* SPDX-License-Identifier: GPL-2.0-or-later */
       2             : /*
       3             :  * i2c-core.h - interfaces internal to the I2C framework
       4             :  */
       5             : 
       6             : #include <linux/rwsem.h>
       7             : 
       8             : struct i2c_devinfo {
       9             :         struct list_head        list;
      10             :         int                     busnum;
      11             :         struct i2c_board_info   board_info;
      12             : };
      13             : 
      14             : /* board_lock protects board_list and first_dynamic_bus_num.
      15             :  * only i2c core components are allowed to use these symbols.
      16             :  */
      17             : extern struct rw_semaphore      __i2c_board_lock;
      18             : extern struct list_head __i2c_board_list;
      19             : extern int              __i2c_first_dynamic_bus_num;
      20             : 
      21             : int i2c_check_7bit_addr_validity_strict(unsigned short addr);
      22             : int i2c_dev_irq_from_resources(const struct resource *resources,
      23             :                                unsigned int num_resources);
      24             : 
      25             : /*
      26             :  * We only allow atomic transfers for very late communication, e.g. to access a
      27             :  * PMIC when powering down. Atomic transfers are a corner case and not for
      28             :  * generic use!
      29             :  */
      30             : static inline bool i2c_in_atomic_xfer_mode(void)
      31             : {
      32           0 :         return system_state > SYSTEM_RUNNING && irqs_disabled();
      33             : }
      34             : 
      35           0 : static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
      36             : {
      37           0 :         int ret = 0;
      38             : 
      39           0 :         if (i2c_in_atomic_xfer_mode()) {
      40           0 :                 WARN(!adap->algo->master_xfer_atomic && !adap->algo->smbus_xfer_atomic,
      41             :                      "No atomic I2C transfer handler for '%s'\n", dev_name(&adap->dev));
      42           0 :                 ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
      43             :         } else {
      44             :                 i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
      45             :         }
      46             : 
      47           0 :         return ret;
      48             : }
      49             : 
      50           0 : static inline int __i2c_check_suspended(struct i2c_adapter *adap)
      51             : {
      52           0 :         if (test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)) {
      53           0 :                 if (!test_and_set_bit(I2C_ALF_SUSPEND_REPORTED, &adap->locked_flags))
      54           0 :                         dev_WARN(&adap->dev, "Transfer while suspended\n");
      55             :                 return -ESHUTDOWN;
      56             :         }
      57             : 
      58             :         return 0;
      59             : }
      60             : 
      61             : #ifdef CONFIG_ACPI
      62             : void i2c_acpi_register_devices(struct i2c_adapter *adap);
      63             : 
      64             : int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable);
      65             : #else /* CONFIG_ACPI */
      66             : static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
      67             : 
      68             : static inline int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable)
      69             : {
      70             :         return 0;
      71             : }
      72             : #endif /* CONFIG_ACPI */
      73             : extern struct notifier_block i2c_acpi_notifier;
      74             : 
      75             : #ifdef CONFIG_ACPI_I2C_OPREGION
      76             : int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
      77             : void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
      78             : #else /* CONFIG_ACPI_I2C_OPREGION */
      79             : static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
      80             : static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
      81             : #endif /* CONFIG_ACPI_I2C_OPREGION */
      82             : 
      83             : #ifdef CONFIG_OF
      84             : void of_i2c_register_devices(struct i2c_adapter *adap);
      85             : #else
      86             : static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
      87             : #endif
      88             : extern struct notifier_block i2c_of_notifier;
      89             : 
      90             : #if IS_ENABLED(CONFIG_I2C_SMBUS)
      91             : int i2c_setup_smbus_alert(struct i2c_adapter *adap);
      92             : #else
      93             : static inline int i2c_setup_smbus_alert(struct i2c_adapter *adap)
      94             : {
      95             :         return 0;
      96             : }
      97             : #endif