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 && !preemptible(); 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, bool *wake_capable); 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, bool *wake_capable) 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; 89 90 #if IS_ENABLED(CONFIG_I2C_SMBUS) 91 int i2c_setup_smbus_alert(struct i2c_adapter *adap); 92 #else 93 static inline int i2c_setup_smbus_alert(struct i2c_adapter *adap) 94 { 95 return 0; 96 } 97 #endif 98