[linux-2.6-block.git] / drivers / i2c / i2c-core.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * i2c-core.h - interfaces internal to the I2C framework
 */

#include <linux/rwsem.h>

struct i2c_devinfo {
	struct list_head	list;
	int			busnum;
	struct i2c_board_info	board_info;
};

/* board_lock protects board_list and first_dynamic_bus_num.
 * only i2c core components are allowed to use these symbols.
 */
extern struct rw_semaphore	__i2c_board_lock;
extern struct list_head	__i2c_board_list;
extern int		__i2c_first_dynamic_bus_num;

int i2c_check_7bit_addr_validity_strict(unsigned short addr);

/*
 * We only allow atomic transfers for very late communication, e.g. to send
 * the powerdown command to a PMIC. Atomic transfers are a corner case and not
 * for generic use!
 */
static inline bool i2c_in_atomic_xfer_mode(void)
{
	return system_state > SYSTEM_RUNNING && irqs_disabled();
}

static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
{
	int ret = 0;

	if (i2c_in_atomic_xfer_mode()) {
		WARN(!adap->algo->master_xfer_atomic && !adap->algo->smbus_xfer_atomic,
		     "No atomic I2C transfer handler for '%s'\n", dev_name(&adap->dev));
		ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
	} else {
		i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
	}

	return ret;
}

static inline int __i2c_check_suspended(struct i2c_adapter *adap)
{
	if (test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)) {
		if (!test_and_set_bit(I2C_ALF_SUSPEND_REPORTED, &adap->locked_flags))
			dev_WARN(&adap->dev, "Transfer while suspended\n");
		return -ESHUTDOWN;
	}

	return 0;
}

#ifdef CONFIG_ACPI
const struct acpi_device_id *
i2c_acpi_match_device(const struct acpi_device_id *matches,
		      struct i2c_client *client);
void i2c_acpi_register_devices(struct i2c_adapter *adap);
#else /* CONFIG_ACPI */
static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
static inline const struct acpi_device_id *
i2c_acpi_match_device(const struct acpi_device_id *matches,
		      struct i2c_client *client)
{
	return NULL;
}
#endif /* CONFIG_ACPI */
extern struct notifier_block i2c_acpi_notifier;

#ifdef CONFIG_ACPI_I2C_OPREGION
int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
#else /* CONFIG_ACPI_I2C_OPREGION */
static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
#endif /* CONFIG_ACPI_I2C_OPREGION */

#ifdef CONFIG_OF
void of_i2c_register_devices(struct i2c_adapter *adap);
#else
static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
#endif
extern struct notifier_block i2c_of_notifier;
Commit	Line	Data
c942fddf	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
9c1600ed DB	2	/*
9c1600ed DB	3	* i2c-core.h - interfaces internal to the I2C framework
9c1600ed DB	4	*/
9c1600ed DB	5
f18c41da RG	6	#include <linux/rwsem.h>
f18c41da RG	7
9c1600ed DB	8	struct 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	*/
f18c41da	17	extern struct rw_semaphore __i2c_board_lock;
9c1600ed DB	18	extern struct list_head __i2c_board_list;
	19	extern int __i2c_first_dynamic_bus_num;
	20
e4991ecd	21	int i2c_check_7bit_addr_validity_strict(unsigned short addr);
5bf4fa7d	22
bae1d3a0 WS	23	/*
	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	*/
	28	static inline bool i2c_in_atomic_xfer_mode(void)
	29	{
	30	return system_state > SYSTEM_RUNNING && irqs_disabled();
	31	}
	32
83c42212 WS	33	static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
	34	{
	35	int ret = 0;
	36
63b96983 WS	37	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));
83c42212	40	ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
63b96983	41	} else {
83c42212	42	i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
63b96983	43	}
83c42212 WS	44
	45	return ret;
	46	}
	47
5d756112 WS	48	static 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
53f8f7c5	59	#ifdef CONFIG_ACPI
c64ffff7 AS	60	const struct acpi_device_id *
	61	i2c_acpi_match_device(const struct acpi_device_id *matches,
	62	struct i2c_client *client);
53f8f7c5 WS	63	void i2c_acpi_register_devices(struct i2c_adapter *adap);
	64	#else /* CONFIG_ACPI */
	65	static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
c64ffff7 AS	66	static inline const struct acpi_device_id *
	67	i2c_acpi_match_device(const struct acpi_device_id *matches,
	68	struct i2c_client *client)
	69	{
	70	return NULL;
	71	}
53f8f7c5 WS	72	#endif /* CONFIG_ACPI */
	73	extern struct notifier_block i2c_acpi_notifier;
	74
	75	#ifdef CONFIG_ACPI_I2C_OPREGION
	76	int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
	77	void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
	78	#else /* CONFIG_ACPI_I2C_OPREGION */
	79	static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
	80	static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
	81	#endif /* CONFIG_ACPI_I2C_OPREGION */
	82
5bf4fa7d WS	83	#ifdef CONFIG_OF
	84	void of_i2c_register_devices(struct i2c_adapter *adap);
	85	#else
	86	static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
	87	#endif
	88	extern struct notifier_block i2c_of_notifier;