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 send
28 * the powerdown command to a PMIC. Atomic transfers are a corner case and not
29 * for 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 const struct acpi_device_id *
65 i2c_acpi_match_device(const struct acpi_device_id *matches,
66 struct i2c_client *client);
67 void i2c_acpi_register_devices(struct i2c_adapter *adap);
68
69 int i2c_acpi_get_irq(struct i2c_client *client);
70 #else /* CONFIG_ACPI */
i2c_acpi_register_devices(struct i2c_adapter * adap)71 static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
72 static inline const struct acpi_device_id *
i2c_acpi_match_device(const struct acpi_device_id * matches,struct i2c_client * client)73 i2c_acpi_match_device(const struct acpi_device_id *matches,
74 struct i2c_client *client)
75 {
76 return NULL;
77 }
78
i2c_acpi_get_irq(struct i2c_client * client)79 static inline int i2c_acpi_get_irq(struct i2c_client *client)
80 {
81 return 0;
82 }
83 #endif /* CONFIG_ACPI */
84 extern struct notifier_block i2c_acpi_notifier;
85
86 #ifdef CONFIG_ACPI_I2C_OPREGION
87 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
88 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
89 #else /* CONFIG_ACPI_I2C_OPREGION */
i2c_acpi_install_space_handler(struct i2c_adapter * adapter)90 static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
i2c_acpi_remove_space_handler(struct i2c_adapter * adapter)91 static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
92 #endif /* CONFIG_ACPI_I2C_OPREGION */
93
94 #ifdef CONFIG_OF
95 void of_i2c_register_devices(struct i2c_adapter *adap);
96 #else
of_i2c_register_devices(struct i2c_adapter * adap)97 static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
98 #endif
99 extern struct notifier_block i2c_of_notifier;
100