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Thomas Gleixnerc942fdd2019-05-27 08:55:06 +02001/* SPDX-License-Identifier: GPL-2.0-or-later */
David Brownell9c1600e2007-05-01 23:26:31 +02002/*
3 * i2c-core.h - interfaces internal to the I2C framework
David Brownell9c1600e2007-05-01 23:26:31 +02004 */
5
Rodolfo Giomettif18c41d2009-06-19 16:58:20 +02006#include <linux/rwsem.h>
7
David Brownell9c1600e2007-05-01 23:26:31 +02008struct 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 */
Rodolfo Giomettif18c41d2009-06-19 16:58:20 +020017extern struct rw_semaphore __i2c_board_lock;
David Brownell9c1600e2007-05-01 23:26:31 +020018extern struct list_head __i2c_board_list;
19extern int __i2c_first_dynamic_bus_num;
20
Wolfram Sange4991ec2017-05-23 11:14:17 +020021int i2c_check_7bit_addr_validity_strict(unsigned short addr);
Wolfram Sang5bf4fa72017-05-23 11:50:58 +020022
Wolfram Sangbae1d3a2019-04-03 14:40:08 +020023/*
24 * We only allow atomic transfers for very late communication, e.g. to send
25 * the powerdown command to a PMIC. Atomic transfers are a corner case and not
26 * for generic use!
27 */
28static inline bool i2c_in_atomic_xfer_mode(void)
29{
30 return system_state > SYSTEM_RUNNING && irqs_disabled();
31}
32
Wolfram Sang83c42212019-04-03 14:40:09 +020033static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
34{
35 int ret = 0;
36
Wolfram Sang63b96982019-04-03 14:40:10 +020037 if (i2c_in_atomic_xfer_mode()) {
38 WARN(!adap->algo->master_xfer_atomic && !adap->algo->smbus_xfer_atomic,
39 "No atomic I2C transfer handler for '%s'\n", dev_name(&adap->dev));
Wolfram Sang83c42212019-04-03 14:40:09 +020040 ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
Wolfram Sang63b96982019-04-03 14:40:10 +020041 } else {
Wolfram Sang83c42212019-04-03 14:40:09 +020042 i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
Wolfram Sang63b96982019-04-03 14:40:10 +020043 }
Wolfram Sang83c42212019-04-03 14:40:09 +020044
45 return ret;
46}
47
Wolfram Sang5d756112019-04-25 16:19:48 +020048static inline int __i2c_check_suspended(struct i2c_adapter *adap)
49{
50 if (test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)) {
51 if (!test_and_set_bit(I2C_ALF_SUSPEND_REPORTED, &adap->locked_flags))
52 dev_WARN(&adap->dev, "Transfer while suspended\n");
53 return -ESHUTDOWN;
54 }
55
56 return 0;
57}
58
Wolfram Sang53f8f7c2017-05-23 16:22:23 +020059#ifdef CONFIG_ACPI
Andy Shevchenkoc64ffff2017-07-17 17:13:28 +030060const struct acpi_device_id *
61i2c_acpi_match_device(const struct acpi_device_id *matches,
62 struct i2c_client *client);
Wolfram Sang53f8f7c2017-05-23 16:22:23 +020063void i2c_acpi_register_devices(struct i2c_adapter *adap);
64#else /* CONFIG_ACPI */
65static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
Andy Shevchenkoc64ffff2017-07-17 17:13:28 +030066static inline const struct acpi_device_id *
67i2c_acpi_match_device(const struct acpi_device_id *matches,
68 struct i2c_client *client)
69{
70 return NULL;
71}
Wolfram Sang53f8f7c2017-05-23 16:22:23 +020072#endif /* CONFIG_ACPI */
73extern struct notifier_block i2c_acpi_notifier;
74
75#ifdef CONFIG_ACPI_I2C_OPREGION
76int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
77void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
78#else /* CONFIG_ACPI_I2C_OPREGION */
79static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
80static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
81#endif /* CONFIG_ACPI_I2C_OPREGION */
82
Wolfram Sang5bf4fa72017-05-23 11:50:58 +020083#ifdef CONFIG_OF
84void of_i2c_register_devices(struct i2c_adapter *adap);
85#else
86static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
87#endif
88extern struct notifier_block i2c_of_notifier;