LXR linux/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
   8struct 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 */
  17extern struct rw_semaphore      __i2c_board_lock;
  18extern struct list_head __i2c_board_list;
  19extern int              __i2c_first_dynamic_bus_num;
  20
  21int i2c_check_7bit_addr_validity_strict(unsigned short addr);
  22int 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 */
  30static inline bool i2c_in_atomic_xfer_mode(void)
  31{
  32        return system_state > SYSTEM_RUNNING && irqs_disabled();
  33}
  34
  35static 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
  50static 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
  62void i2c_acpi_register_devices(struct i2c_adapter *adap);
  63
  64int i2c_acpi_get_irq(struct i2c_client *client);
  65#else /* CONFIG_ACPI */
  66static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
  67
  68static inline int i2c_acpi_get_irq(struct i2c_client *client)
  69{
  70        return 0;
  71}
  72#endif /* CONFIG_ACPI */
  73extern struct notifier_block i2c_acpi_notifier;
  74
  75#ifdef CONFIG_ACPI_I2C_OPREGION
  76int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
  77void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
  78#else /* CONFIG_ACPI_I2C_OPREGION */
  79static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
  80static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
  81#endif /* CONFIG_ACPI_I2C_OPREGION */
  82
  83#ifdef CONFIG_OF
  84void of_i2c_register_devices(struct i2c_adapter *adap);
  85#else
  86static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
  87#endif
  88extern struct notifier_block i2c_of_notifier;
  89