drivers/i2c/i2c-core.h

   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
  23 /*
  24  * We only allow atomic transfers for very late communication, e.g. to send
  25  * the powerdown command to a PMIC. Atomic transfers are a corner case and not
  26  * for generic use!
  27  */
  28 static inline bool i2c_in_atomic_xfer_mode(void)
  29 {
  30         return system_state > SYSTEM_RUNNING && irqs_disabled();
  31 }
  32
  33 static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
  34 {
  35         int ret = 0;
  36
  37         if (i2c_in_atomic_xfer_mode()) {
  38                 WARN(!adap->algo->master_xfer_atomic && !adap->algo->smbus_xfer_atomic,
  39                      "No atomic I2C transfer handler for '%s'\n", dev_name(&adap->dev));
  40                 ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
  41         } else {
  42                 i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
  43         }
  44
  45         return ret;
  46 }
  47
  48 static inline int __i2c_check_suspended(struct i2c_adapter *adap)
  49 {
  50         if (test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)) {
  51                 if (!test_and_set_bit(I2C_ALF_SUSPEND_REPORTED, &adap->locked_flags))
  52                         dev_WARN(&adap->dev, "Transfer while suspended\n");
  53                 return -ESHUTDOWN;
  54         }
  55
  56         return 0;
  57 }
  58
  59 #ifdef CONFIG_ACPI
  60 const struct acpi_device_id *
  61 i2c_acpi_match_device(const struct acpi_device_id *matches,
  62                       struct i2c_client *client);
  63 void i2c_acpi_register_devices(struct i2c_adapter *adap);
  64 #else /* CONFIG_ACPI */
  65 static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
  66 static inline const struct acpi_device_id *
  67 i2c_acpi_match_device(const struct acpi_device_id *matches,
  68                       struct i2c_client *client)
  69 {
  70         return NULL;
  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;