1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 *
4 * i2c-mux.h - functions for the i2c-bus mux support
5 *
6 * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
7 * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
8 * Michael Lawnick <michael.lawnick.ext@nsn.com>
9 */
10
11 #ifndef _LINUX_I2C_MUX_H
12 #define _LINUX_I2C_MUX_H
13
14 #ifdef __KERNEL__
15
16 #include <linux/bitops.h>
17
18 struct i2c_mux_core {
19 struct i2c_adapter *parent;
20 struct device *dev;
21 unsigned int mux_locked:1;
22 unsigned int arbitrator:1;
23 unsigned int gate:1;
24
25 void *priv;
26
27 int (*select)(struct i2c_mux_core *, u32 chan_id);
28 int (*deselect)(struct i2c_mux_core *, u32 chan_id);
29
30 int num_adapters;
31 int max_adapters;
32 struct i2c_adapter *adapter[];
33 };
34
35 struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
36 struct device *dev, int max_adapters,
37 int sizeof_priv, u32 flags,
38 int (*select)(struct i2c_mux_core *, u32),
39 int (*deselect)(struct i2c_mux_core *, u32));
40
41 /* flags for i2c_mux_alloc */
42 #define I2C_MUX_LOCKED BIT(0)
43 #define I2C_MUX_ARBITRATOR BIT(1)
44 #define I2C_MUX_GATE BIT(2)
45
46 static inline void *i2c_mux_priv(struct i2c_mux_core *muxc)
47 {
48 return muxc->priv;
49 }
50
51 struct i2c_adapter *i2c_root_adapter(struct device *dev);
52
53 /*
54 * Called to create an i2c bus on a multiplexed bus segment.
55 * The chan_id parameter is passed to the select and deselect
56 * callback functions to perform hardware-specific mux control.
57 */
58 int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
59 u32 force_nr, u32 chan_id);
60
61 void i2c_mux_del_adapters(struct i2c_mux_core *muxc);
62
63 #endif /* __KERNEL__ */
64
65 #endif /* _LINUX_I2C_MUX_H */
66
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