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  */
i2c_in_atomic_xfer_mode(void)30 static inline bool i2c_in_atomic_xfer_mode(void)
31 {
32 	return system_state > SYSTEM_RUNNING && irqs_disabled();
33 }
34 
__i2c_lock_bus_helper(struct i2c_adapter * adap)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 
__i2c_check_suspended(struct i2c_adapter * adap)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);
65 #else /* CONFIG_ACPI */
i2c_acpi_register_devices(struct i2c_adapter * adap)66 static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
67 
i2c_acpi_get_irq(struct i2c_client * client)68 static inline int i2c_acpi_get_irq(struct i2c_client *client)
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 */
i2c_acpi_install_space_handler(struct i2c_adapter * adapter)79 static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
i2c_acpi_remove_space_handler(struct i2c_adapter * adapter)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
of_i2c_register_devices(struct i2c_adapter * adap)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
i2c_setup_smbus_alert(struct i2c_adapter * adap)93 static inline int i2c_setup_smbus_alert(struct i2c_adapter *adap)
94 {
95 	return 0;
96 }
97 #endif
98