100 lines · c
1/* SPDX-License-Identifier: GPL-2.0-or-later */2/*3 * i2c-core.h - interfaces internal to the I2C framework4 */5 6#include <linux/kconfig.h>7#include <linux/rwsem.h>8 9struct 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 */18extern struct rw_semaphore __i2c_board_lock;19extern struct list_head __i2c_board_list;20extern int __i2c_first_dynamic_bus_num;21 22int i2c_check_7bit_addr_validity_strict(unsigned short addr);23int 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 a28 * PMIC when powering down. Atomic transfers are a corner case and not for29 * generic use!30 */31static 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 37static 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 52static 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_ACPI64void i2c_acpi_register_devices(struct i2c_adapter *adap);65 66int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable);67#else /* CONFIG_ACPI */68static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }69 70static inline int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable)71{72 return 0;73}74#endif /* CONFIG_ACPI */75extern struct notifier_block i2c_acpi_notifier;76 77#ifdef CONFIG_ACPI_I2C_OPREGION78int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);79void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);80#else /* CONFIG_ACPI_I2C_OPREGION */81static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }82static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }83#endif /* CONFIG_ACPI_I2C_OPREGION */84 85#ifdef CONFIG_OF86void of_i2c_register_devices(struct i2c_adapter *adap);87#else88static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }89#endif90extern struct notifier_block i2c_of_notifier;91 92#if IS_ENABLED(CONFIG_I2C_SMBUS)93int i2c_setup_smbus_alert(struct i2c_adapter *adap);94#else95static inline int i2c_setup_smbus_alert(struct i2c_adapter *adap)96{97 return 0;98}99#endif100