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