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 unsigned int mux_locked:1; 36 unsigned int arbitrator:1; 37 unsigned int gate:1; 38 39 void *priv; 40 41 int (*select)(struct i2c_mux_core *, u32 chan_id); 42 int (*deselect)(struct i2c_mux_core *, u32 chan_id); 43 44 int num_adapters; 45 int max_adapters; 46 struct i2c_adapter *adapter[0]; 47 }; 48 49 struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent, 50 struct device *dev, int max_adapters, 51 int sizeof_priv, u32 flags, 52 int (*select)(struct i2c_mux_core *, u32), 53 int (*deselect)(struct i2c_mux_core *, u32)); 54 55 /* flags for i2c_mux_alloc */ 56 #define I2C_MUX_LOCKED BIT(0) 57 #define I2C_MUX_ARBITRATOR BIT(1) 58 #define I2C_MUX_GATE BIT(2) 59 60 static inline void *i2c_mux_priv(struct i2c_mux_core *muxc) 61 { 62 return muxc->priv; 63 } 64 65 struct i2c_adapter *i2c_root_adapter(struct device *dev); 66 67 /* 68 * Called to create an i2c bus on a multiplexed bus segment. 69 * The chan_id parameter is passed to the select and deselect 70 * callback functions to perform hardware-specific mux control. 71 */ 72 int i2c_mux_add_adapter(struct i2c_mux_core *muxc, 73 u32 force_nr, u32 chan_id, 74 unsigned int class); 75 76 void i2c_mux_del_adapters(struct i2c_mux_core *muxc); 77 78 #endif /* __KERNEL__ */ 79 80 #endif /* _LINUX_I2C_MUX_H */ 81