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 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         return system_state > SYSTEM_RUNNING && irqs_disabled();
  33 }
  34
  35 static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
  36 {
  37         int ret = 0;
  38
  39         if (i2c_in_atomic_xfer_mode()) {
  40                 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                 ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
  43         } else {
  44                 i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
  45         }
  46
  47         return ret;
  48 }
  49
  50 static inline int __i2c_check_suspended(struct i2c_adapter *adap)
  51 {
  52         if (test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)) {
  53                 if (!test_and_set_bit(I2C_ALF_SUSPEND_REPORTED, &adap->locked_flags))
  54                         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);
  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)
  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;