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 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 a 28 * PMIC when powering down. Atomic transfers are a corner case and not for 29 * 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_ACPI 64void 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_OPREGION 78int 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_OF 86void of_i2c_register_devices(struct i2c_adapter *adap); 87#else 88static inline void of_i2c_register_devices(struct i2c_adapter *adap) { } 89#endif 90extern struct notifier_block i2c_of_notifier; 91 92#if IS_ENABLED(CONFIG_I2C_SMBUS) 93int i2c_setup_smbus_alert(struct i2c_adapter *adap); 94#else 95static inline int i2c_setup_smbus_alert(struct i2c_adapter *adap) 96{ 97 return 0; 98} 99#endif 100