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