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[0]; 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 unsigned int class); 61 62 void i2c_mux_del_adapters(struct i2c_mux_core *muxc); 63 64 #endif /* __KERNEL__ */ 65 66 #endif /* _LINUX_I2C_MUX_H */ 67