include/linux/i2c-mux.h

   1 /*
   2  *
   3  * i2c-mux.h - functions for the i2c-bus mux support
   4  *
   5  * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
   6  * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
   7  * Michael Lawnick <michael.lawnick.ext@nsn.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  22  * MA 02110-1301 USA.
  23  */
  24
  25 #ifndef _LINUX_I2C_MUX_H
  26 #define _LINUX_I2C_MUX_H
  27
  28 #ifdef __KERNEL__
  29
  30 #include <linux/bitops.h>
  31
  32 struct i2c_mux_core {
  33         struct i2c_adapter *parent;
  34         struct device *dev;
  35         bool mux_locked;
  36
  37         void *priv;
  38
  39         int (*select)(struct i2c_mux_core *, u32 chan_id);
  40         int (*deselect)(struct i2c_mux_core *, u32 chan_id);
  41
  42         int num_adapters;
  43         int max_adapters;
  44         struct i2c_adapter *adapter[0];
  45 };
  46
  47 struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
  48                                    struct device *dev, int max_adapters,
  49                                    int sizeof_priv, u32 flags,
  50                                    int (*select)(struct i2c_mux_core *, u32),
  51                                    int (*deselect)(struct i2c_mux_core *, u32));
  52
  53 /* flags for i2c_mux_alloc */
  54 #define I2C_MUX_LOCKED BIT(0)
  55
  56 static inline void *i2c_mux_priv(struct i2c_mux_core *muxc)
  57 {
  58         return muxc->priv;
  59 }
  60
  61 struct i2c_adapter *i2c_root_adapter(struct device *dev);
  62
  63 /*
  64  * Called to create an i2c bus on a multiplexed bus segment.
  65  * The chan_id parameter is passed to the select and deselect
  66  * callback functions to perform hardware-specific mux control.
  67  */
  68 int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
  69                         u32 force_nr, u32 chan_id,
  70                         unsigned int class);
  71
  72 void i2c_mux_del_adapters(struct i2c_mux_core *muxc);
  73
  74 #endif /* __KERNEL__ */
  75
  76 #endif /* _LINUX_I2C_MUX_H */