include/linux/i2c-mux.h

   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 */