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 */ i2c_in_atomic_xfer_mode(void)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 __i2c_lock_bus_helper(struct i2c_adapter * adap)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 __i2c_check_suspended(struct i2c_adapter * adap)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, bool *wake_capable); 67 #else /* CONFIG_ACPI */ i2c_acpi_register_devices(struct i2c_adapter * adap)68 static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { } 69 i2c_acpi_get_irq(struct i2c_client * client,bool * wake_capable)70 static inline int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable) 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 */ i2c_acpi_install_space_handler(struct i2c_adapter * adapter)81 static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; } i2c_acpi_remove_space_handler(struct i2c_adapter * adapter)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 of_i2c_register_devices(struct i2c_adapter * adap)88 static inline void of_i2c_register_devices(struct i2c_adapter *adap) { } 89 #endif 90 extern struct notifier_block i2c_of_notifier; 91 92 #if IS_ENABLED(CONFIG_I2C_SMBUS) 93 int i2c_setup_smbus_alert(struct i2c_adapter *adap); 94 #else i2c_setup_smbus_alert(struct i2c_adapter * adap)95 static inline int i2c_setup_smbus_alert(struct i2c_adapter *adap) 96 { 97 return 0; 98 } 99 #endif 100