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/i2c.h>
7 #include <linux/kconfig.h>
8 #include <linux/rwsem.h>
9
10 struct i2c_devinfo {
11 struct list_head list;
12 int busnum;
13 struct i2c_board_info board_info;
14 };
15
16 /* board_lock protects board_list and first_dynamic_bus_num.
17 * only i2c core components are allowed to use these symbols.
18 */
19 extern struct rw_semaphore __i2c_board_lock;
20 extern struct list_head __i2c_board_list;
21 extern int __i2c_first_dynamic_bus_num;
22
23 int i2c_check_7bit_addr_validity_strict(unsigned short addr);
24 int i2c_dev_irq_from_resources(const struct resource *resources,
25 unsigned int num_resources);
26
27 /*
28 * We only allow atomic transfers for very late communication, e.g. to access a
29 * PMIC when powering down. Atomic transfers are a corner case and not for
30 * generic use!
31 */
i2c_in_atomic_xfer_mode(void)32 static inline bool i2c_in_atomic_xfer_mode(void)
33 {
34 return system_state > SYSTEM_RUNNING &&
35 (IS_ENABLED(CONFIG_PREEMPT_COUNT) ? !preemptible() : irqs_disabled());
36 }
37
__i2c_lock_bus_helper(struct i2c_adapter * adap)38 static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
39 {
40 int ret = 0;
41
42 if (i2c_in_atomic_xfer_mode()) {
43 WARN(!adap->algo->master_xfer_atomic && !adap->algo->smbus_xfer_atomic,
44 "No atomic I2C transfer handler for '%s'\n", dev_name(&adap->dev));
45 ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
46 } else {
47 i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
48 }
49
50 return ret;
51 }
52
__i2c_check_suspended(struct i2c_adapter * adap)53 static inline int __i2c_check_suspended(struct i2c_adapter *adap)
54 {
55 if (test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)) {
56 if (!test_and_set_bit(I2C_ALF_SUSPEND_REPORTED, &adap->locked_flags))
57 dev_WARN(&adap->dev, "Transfer while suspended\n");
58 return -ESHUTDOWN;
59 }
60
61 return 0;
62 }
63
64 #ifdef CONFIG_ACPI
65 void i2c_acpi_register_devices(struct i2c_adapter *adap);
66
67 int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable);
68 #else /* CONFIG_ACPI */
i2c_acpi_register_devices(struct i2c_adapter * adap)69 static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
70
i2c_acpi_get_irq(struct i2c_client * client,bool * wake_capable)71 static inline int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable)
72 {
73 return 0;
74 }
75 #endif /* CONFIG_ACPI */
76 extern struct notifier_block i2c_acpi_notifier;
77
78 #ifdef CONFIG_ACPI_I2C_OPREGION
79 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
80 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
81 #else /* CONFIG_ACPI_I2C_OPREGION */
i2c_acpi_install_space_handler(struct i2c_adapter * adapter)82 static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
i2c_acpi_remove_space_handler(struct i2c_adapter * adapter)83 static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
84 #endif /* CONFIG_ACPI_I2C_OPREGION */
85
86 #ifdef CONFIG_OF
87 void of_i2c_register_devices(struct i2c_adapter *adap);
88 const struct of_device_id *i2c_of_match_device(const struct of_device_id *matches,
89 struct i2c_client *client);
90
91 #else
of_i2c_register_devices(struct i2c_adapter * adap)92 static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
93 static inline
i2c_of_match_device(const struct of_device_id * matches,struct i2c_client * client)94 const struct of_device_id *i2c_of_match_device(const struct of_device_id *matches,
95 struct i2c_client *client)
96 {
97 return NULL;
98 }
99 #endif
100 extern struct notifier_block i2c_of_notifier;
101
102 #if IS_ENABLED(CONFIG_I2C_SMBUS)
103 int i2c_setup_smbus_alert(struct i2c_adapter *adap);
104 #else
i2c_setup_smbus_alert(struct i2c_adapter * adap)105 static inline int i2c_setup_smbus_alert(struct i2c_adapter *adap)
106 {
107 return 0;
108 }
109 #endif
110