LXR linux/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
  18struct 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
  35struct 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
  46static inline void *i2c_mux_priv(struct i2c_mux_core *muxc)
  47{
  48        return muxc->priv;
  49}
  50
  51struct 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 */
  58int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
  59                        u32 force_nr, u32 chan_id,
  60                        unsigned int class);
  61
  62void i2c_mux_del_adapters(struct i2c_mux_core *muxc);
  63
  64#endif /* __KERNEL__ */
  65
  66#endif /* _LINUX_I2C_MUX_H */
  67