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1 /*
2  * i2c-smbus.h - SMBus extensions to the I2C protocol
3  *
4  * Copyright (C) 2010 Jean Delvare <jdelvare@suse.de>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
19  * MA 02110-1301 USA.
20  */
21 
22 #ifndef _LINUX_I2C_SMBUS_H
23 #define _LINUX_I2C_SMBUS_H
24 
25 #include <linux/i2c.h>
26 #include <linux/spinlock.h>
27 #include <linux/workqueue.h>
28 
29 
30 /**
31  * i2c_smbus_alert_setup - platform data for the smbus_alert i2c client
32  * @alert_edge_triggered: whether the alert interrupt is edge (1) or level (0)
33  *		triggered
34  * @irq: IRQ number, if the smbus_alert driver should take care of interrupt
35  *		handling
36  *
37  * If irq is not specified, the smbus_alert driver doesn't take care of
38  * interrupt handling. In that case it is up to the I2C bus driver to either
39  * handle the interrupts or to poll for alerts.
40  *
41  * If irq is specified then it it crucial that alert_edge_triggered is
42  * properly set.
43  */
44 struct i2c_smbus_alert_setup {
45 	unsigned int		alert_edge_triggered:1;
46 	int			irq;
47 };
48 
49 struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
50 					 struct i2c_smbus_alert_setup *setup);
51 int i2c_handle_smbus_alert(struct i2c_client *ara);
52 
53 /**
54  * smbus_host_notify - internal structure used by the Host Notify mechanism.
55  * @adapter: the I2C adapter associated with this struct
56  * @work: worker used to schedule the IRQ in the slave device
57  * @lock: spinlock to check if a notification is already pending
58  * @pending: flag set when a notification is pending (any new notification will
59  *		be rejected if pending is true)
60  * @payload: the actual payload of the Host Notify event
61  * @addr: the address of the slave device which raised the notification
62  *
63  * This struct needs to be allocated by i2c_setup_smbus_host_notify() and does
64  * not need to be freed. Internally, i2c_setup_smbus_host_notify() uses a
65  * managed resource to clean this up when the adapter get released.
66  */
67 struct smbus_host_notify {
68 	struct i2c_adapter	*adapter;
69 	struct work_struct	work;
70 	spinlock_t		lock;
71 	bool			pending;
72 	u16			payload;
73 	u8			addr;
74 };
75 
76 struct smbus_host_notify *i2c_setup_smbus_host_notify(struct i2c_adapter *adap);
77 int i2c_handle_smbus_host_notify(struct smbus_host_notify *host_notify,
78 				 unsigned short addr, unsigned int data);
79 
80 #endif /* _LINUX_I2C_SMBUS_H */
81