tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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
9struct 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 */
18extern struct rw_semaphore __i2c_board_lock;
19extern struct list_head __i2c_board_list;
20extern int __i2c_first_dynamic_bus_num;
21
22int i2c_check_7bit_addr_validity_strict(unsigned short addr);
23int 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 */
31static 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
37static 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
52static 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
64void i2c_acpi_register_devices(struct i2c_adapter *adap);
65
66int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable);
67#else /* CONFIG_ACPI */
68static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
69
70static inline int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable)
71{
72 return 0;
73}
74#endif /* CONFIG_ACPI */
75extern struct notifier_block i2c_acpi_notifier;
76
77#ifdef CONFIG_ACPI_I2C_OPREGION
78int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
79void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
80#else /* CONFIG_ACPI_I2C_OPREGION */
81static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
82static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
83#endif /* CONFIG_ACPI_I2C_OPREGION */
84
85#ifdef CONFIG_OF
86void of_i2c_register_devices(struct i2c_adapter *adap);
87const struct of_device_id *i2c_of_match_device(const struct of_device_id *matches,
88 struct i2c_client *client);
89
90#else
91static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
92static inline
93const struct of_device_id *i2c_of_match_device(const struct of_device_id *matches,
94 struct i2c_client *client)
95{
96 return NULL;
97}
98#endif
99extern struct notifier_block i2c_of_notifier;
100
101#if IS_ENABLED(CONFIG_I2C_SMBUS)
102int i2c_setup_smbus_alert(struct i2c_adapter *adap);
103#else
104static inline int i2c_setup_smbus_alert(struct i2c_adapter *adap)
105{
106 return 0;
107}
108#endif