2019-05-27 14:55:06 +08:00
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/* SPDX-License-Identifier: GPL-2.0-or-later */
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i2c: Add i2c_board_info and i2c_new_device()
This provides partial support for new-style I2C driver binding. It builds
on "struct i2c_board_info" declarations that identify I2C devices on a given
board. This is needed on systems with I2C devices that can't be fully probed
and/or autoconfigured, such as many embedded Linux configurations where the
way a given I2C device is wired may affect how it must be used.
There are two models for declaring such devices:
* LATE -- using a public function i2c_new_device(). This lets modules
declare I2C devices found *AFTER* a given I2C adapter becomes available.
For example, a PCI card could create adapters giving access to utility
chips on that card, and this would be used to associate those chips with
those adapters.
* EARLY -- from arch_initcall() level code, using a non-exported function
i2c_register_board_info(). This copies the declarations *BEFORE* such
an i2c_adapter becomes available, arranging that i2c_new_device() will
be called later when i2c-core registers the relevant i2c_adapter.
For example, arch/.../.../board-*.c files would declare the I2C devices
along with their platform data, and I2C devices would behave much like
PNPACPI devices. (That is, both enumerate from board-specific tables.)
To match the exported i2c_new_device(), the previously-private function
i2c_unregister_device() is now exported.
Pending later patches using these new APIs, this is effectively a NOP.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-02 05:26:31 +08:00
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/*
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* i2c-core.h - interfaces internal to the I2C framework
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*/
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2009-06-19 22:58:20 +08:00
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#include <linux/rwsem.h>
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i2c: Add i2c_board_info and i2c_new_device()
This provides partial support for new-style I2C driver binding. It builds
on "struct i2c_board_info" declarations that identify I2C devices on a given
board. This is needed on systems with I2C devices that can't be fully probed
and/or autoconfigured, such as many embedded Linux configurations where the
way a given I2C device is wired may affect how it must be used.
There are two models for declaring such devices:
* LATE -- using a public function i2c_new_device(). This lets modules
declare I2C devices found *AFTER* a given I2C adapter becomes available.
For example, a PCI card could create adapters giving access to utility
chips on that card, and this would be used to associate those chips with
those adapters.
* EARLY -- from arch_initcall() level code, using a non-exported function
i2c_register_board_info(). This copies the declarations *BEFORE* such
an i2c_adapter becomes available, arranging that i2c_new_device() will
be called later when i2c-core registers the relevant i2c_adapter.
For example, arch/.../.../board-*.c files would declare the I2C devices
along with their platform data, and I2C devices would behave much like
PNPACPI devices. (That is, both enumerate from board-specific tables.)
To match the exported i2c_new_device(), the previously-private function
i2c_unregister_device() is now exported.
Pending later patches using these new APIs, this is effectively a NOP.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-02 05:26:31 +08:00
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struct i2c_devinfo {
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struct list_head list;
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int busnum;
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struct i2c_board_info board_info;
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};
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/* board_lock protects board_list and first_dynamic_bus_num.
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* only i2c core components are allowed to use these symbols.
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*/
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2009-06-19 22:58:20 +08:00
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extern struct rw_semaphore __i2c_board_lock;
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i2c: Add i2c_board_info and i2c_new_device()
This provides partial support for new-style I2C driver binding. It builds
on "struct i2c_board_info" declarations that identify I2C devices on a given
board. This is needed on systems with I2C devices that can't be fully probed
and/or autoconfigured, such as many embedded Linux configurations where the
way a given I2C device is wired may affect how it must be used.
There are two models for declaring such devices:
* LATE -- using a public function i2c_new_device(). This lets modules
declare I2C devices found *AFTER* a given I2C adapter becomes available.
For example, a PCI card could create adapters giving access to utility
chips on that card, and this would be used to associate those chips with
those adapters.
* EARLY -- from arch_initcall() level code, using a non-exported function
i2c_register_board_info(). This copies the declarations *BEFORE* such
an i2c_adapter becomes available, arranging that i2c_new_device() will
be called later when i2c-core registers the relevant i2c_adapter.
For example, arch/.../.../board-*.c files would declare the I2C devices
along with their platform data, and I2C devices would behave much like
PNPACPI devices. (That is, both enumerate from board-specific tables.)
To match the exported i2c_new_device(), the previously-private function
i2c_unregister_device() is now exported.
Pending later patches using these new APIs, this is effectively a NOP.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-02 05:26:31 +08:00
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extern struct list_head __i2c_board_list;
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extern int __i2c_first_dynamic_bus_num;
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2017-05-23 17:14:17 +08:00
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int i2c_check_7bit_addr_validity_strict(unsigned short addr);
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2017-05-23 17:50:58 +08:00
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2019-04-03 20:40:08 +08:00
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/*
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* We only allow atomic transfers for very late communication, e.g. to send
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* the powerdown command to a PMIC. Atomic transfers are a corner case and not
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* for generic use!
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*/
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static inline bool i2c_in_atomic_xfer_mode(void)
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{
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return system_state > SYSTEM_RUNNING && irqs_disabled();
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}
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2019-04-03 20:40:09 +08:00
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static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
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{
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int ret = 0;
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2019-04-03 20:40:10 +08:00
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if (i2c_in_atomic_xfer_mode()) {
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WARN(!adap->algo->master_xfer_atomic && !adap->algo->smbus_xfer_atomic,
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"No atomic I2C transfer handler for '%s'\n", dev_name(&adap->dev));
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2019-04-03 20:40:09 +08:00
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ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
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2019-04-03 20:40:10 +08:00
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} else {
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2019-04-03 20:40:09 +08:00
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i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
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2019-04-03 20:40:10 +08:00
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}
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2019-04-03 20:40:09 +08:00
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return ret;
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}
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2019-04-25 22:19:48 +08:00
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static inline int __i2c_check_suspended(struct i2c_adapter *adap)
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{
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if (test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)) {
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if (!test_and_set_bit(I2C_ALF_SUSPEND_REPORTED, &adap->locked_flags))
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dev_WARN(&adap->dev, "Transfer while suspended\n");
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return -ESHUTDOWN;
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}
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return 0;
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}
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2017-05-23 22:22:23 +08:00
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#ifdef CONFIG_ACPI
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2017-07-17 22:13:28 +08:00
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const struct acpi_device_id *
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i2c_acpi_match_device(const struct acpi_device_id *matches,
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struct i2c_client *client);
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2017-05-23 22:22:23 +08:00
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void i2c_acpi_register_devices(struct i2c_adapter *adap);
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#else /* CONFIG_ACPI */
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static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
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2017-07-17 22:13:28 +08:00
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static inline const struct acpi_device_id *
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i2c_acpi_match_device(const struct acpi_device_id *matches,
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struct i2c_client *client)
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{
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return NULL;
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}
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2017-05-23 22:22:23 +08:00
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#endif /* CONFIG_ACPI */
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extern struct notifier_block i2c_acpi_notifier;
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#ifdef CONFIG_ACPI_I2C_OPREGION
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int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
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void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
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#else /* CONFIG_ACPI_I2C_OPREGION */
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static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
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static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
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#endif /* CONFIG_ACPI_I2C_OPREGION */
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2017-05-23 17:50:58 +08:00
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#ifdef CONFIG_OF
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void of_i2c_register_devices(struct i2c_adapter *adap);
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#else
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static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
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#endif
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extern struct notifier_block i2c_of_notifier;
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