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/i2c.h> 7 #include <linux/kconfig.h> 8 #include <linux/rwsem.h> 9 10 struct i2c_devinfo { 11 struct list_head list; 12 int busnum; 13 struct i2c_board_info board_info; 14 }; 15 16 /* board_lock protects board_list and first_dynamic_bus_num. 17 * only i2c core components are allowed to use these symbols. 18 */ 19 extern struct rw_semaphore __i2c_board_lock; 20 extern struct list_head __i2c_board_list; 21 extern int __i2c_first_dynamic_bus_num; 22 23 int i2c_check_7bit_addr_validity_strict(unsigned short addr); 24 int i2c_dev_irq_from_resources(const struct resource *resources, 25 unsigned int num_resources); 26 27 /* 28 * We only allow atomic transfers for very late communication, e.g. to access a 29 * PMIC when powering down. Atomic transfers are a corner case and not for 30 * generic use! 31 */ 32 static inline bool i2c_in_atomic_xfer_mode(void) 33 { 34 return system_state > SYSTEM_RUNNING && 35 (IS_ENABLED(CONFIG_PREEMPT_COUNT) ? !preemptible() : irqs_disabled()); 36 } 37 38 static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap) 39 { 40 int ret = 0; 41 42 if (i2c_in_atomic_xfer_mode()) { 43 WARN(!adap->algo->master_xfer_atomic && !adap->algo->smbus_xfer_atomic, 44 "No atomic I2C transfer handler for '%s'\n", dev_name(&adap->dev)); 45 ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN; 46 } else { 47 i2c_lock_bus(adap, I2C_LOCK_SEGMENT); 48 } 49 50 return ret; 51 } 52 53 static inline int __i2c_check_suspended(struct i2c_adapter *adap) 54 { 55 if (test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)) { 56 if (!test_and_set_bit(I2C_ALF_SUSPEND_REPORTED, &adap->locked_flags)) 57 dev_WARN(&adap->dev, "Transfer while suspended\n"); 58 return -ESHUTDOWN; 59 } 60 61 return 0; 62 } 63 64 #ifdef CONFIG_ACPI 65 void i2c_acpi_register_devices(struct i2c_adapter *adap); 66 67 int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable); 68 #else /* CONFIG_ACPI */ 69 static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { } 70 71 static inline int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable) 72 { 73 return 0; 74 } 75 #endif /* CONFIG_ACPI */ 76 extern struct notifier_block i2c_acpi_notifier; 77 78 #ifdef CONFIG_ACPI_I2C_OPREGION 79 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter); 80 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter); 81 #else /* CONFIG_ACPI_I2C_OPREGION */ 82 static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; } 83 static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { } 84 #endif /* CONFIG_ACPI_I2C_OPREGION */ 85 86 #ifdef CONFIG_OF 87 void of_i2c_register_devices(struct i2c_adapter *adap); 88 const struct of_device_id *i2c_of_match_device(const struct of_device_id *matches, 89 struct i2c_client *client); 90 91 #else 92 static inline void of_i2c_register_devices(struct i2c_adapter *adap) { } 93 static inline 94 const struct of_device_id *i2c_of_match_device(const struct of_device_id *matches, 95 struct i2c_client *client) 96 { 97 return NULL; 98 } 99 #endif 100 extern struct notifier_block i2c_of_notifier; 101 102 #if IS_ENABLED(CONFIG_I2C_SMBUS) 103 int i2c_setup_smbus_alert(struct i2c_adapter *adap); 104 #else 105 static inline int i2c_setup_smbus_alert(struct i2c_adapter *adap) 106 { 107 return 0; 108 } 109 #endif 110