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 | */ |
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 | |
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(adapter: adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN; |
45 | } else { |
46 | i2c_lock_bus(adapter: adap, I2C_LOCK_SEGMENT); |
47 | } |
48 | |
49 | return ret; |
50 | } |
51 | |
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, addr: &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 */ |
68 | static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { } |
69 | |
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 */ |
81 | static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; } |
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 |
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 |
95 | static inline int i2c_setup_smbus_alert(struct i2c_adapter *adap) |
96 | { |
97 | return 0; |
98 | } |
99 | #endif |
100 | |