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/drivers/i2c/i2c-core.h

http://github.com/mirrors/linux
C Header | 97 lines | 70 code | 15 blank | 12 comment | 6 complexity | 5f67962fd00f183aeae412703d8af78b MD5 | raw file
 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
 8struct 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 */
17extern struct rw_semaphore	__i2c_board_lock;
18extern struct list_head	__i2c_board_list;
19extern int		__i2c_first_dynamic_bus_num;
20
21int i2c_check_7bit_addr_validity_strict(unsigned short addr);
22int 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 send
27 * the powerdown command to a PMIC. Atomic transfers are a corner case and not
28 * for generic use!
29 */
30static inline bool i2c_in_atomic_xfer_mode(void)
31{
32	return system_state > SYSTEM_RUNNING && irqs_disabled();
33}
34
35static 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
50static 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
62const struct acpi_device_id *
63i2c_acpi_match_device(const struct acpi_device_id *matches,
64		      struct i2c_client *client);
65void i2c_acpi_register_devices(struct i2c_adapter *adap);
66
67int i2c_acpi_get_irq(struct i2c_client *client);
68#else /* CONFIG_ACPI */
69static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
70static inline const struct acpi_device_id *
71i2c_acpi_match_device(const struct acpi_device_id *matches,
72		      struct i2c_client *client)
73{
74	return NULL;
75}
76
77static inline int i2c_acpi_get_irq(struct i2c_client *client)
78{
79	return 0;
80}
81#endif /* CONFIG_ACPI */
82extern struct notifier_block i2c_acpi_notifier;
83
84#ifdef CONFIG_ACPI_I2C_OPREGION
85int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
86void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
87#else /* CONFIG_ACPI_I2C_OPREGION */
88static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
89static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
90#endif /* CONFIG_ACPI_I2C_OPREGION */
91
92#ifdef CONFIG_OF
93void of_i2c_register_devices(struct i2c_adapter *adap);
94#else
95static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
96#endif
97extern struct notifier_block i2c_of_notifier;