1 /* 2 * mux/driver.h - definitions for the multiplexer driver interface 3 * 4 * Copyright (C) 2017 Axentia Technologies AB 5 * 6 * Author: Peter Rosin <[email protected]> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #ifndef _LINUX_MUX_DRIVER_H 14 #define _LINUX_MUX_DRIVER_H 15 16 #include <dt-bindings/mux/mux.h> 17 #include <linux/device.h> 18 #include <linux/semaphore.h> 19 20 struct mux_chip; 21 struct mux_control; 22 23 /** 24 * struct mux_control_ops - Mux controller operations for a mux chip. 25 * @set: Set the state of the given mux controller. 26 */ 27 struct mux_control_ops { 28 int (*set)(struct mux_control *mux, int state); 29 }; 30 31 /** 32 * struct mux_control - Represents a mux controller. 33 * @lock: Protects the mux controller state. 34 * @chip: The mux chip that is handling this mux controller. 35 * @cached_state: The current mux controller state, or -1 if none. 36 * @states: The number of mux controller states. 37 * @idle_state: The mux controller state to use when inactive, or one 38 * of MUX_IDLE_AS_IS and MUX_IDLE_DISCONNECT. 39 * 40 * Mux drivers may only change @states and @idle_state, and may only do so 41 * between allocation and registration of the mux controller. Specifically, 42 * @cached_state is internal to the mux core and should never be written by 43 * mux drivers. 44 */ 45 struct mux_control { 46 struct semaphore lock; /* protects the state of the mux */ 47 48 struct mux_chip *chip; 49 int cached_state; 50 51 unsigned int states; 52 int idle_state; 53 }; 54 55 /** 56 * struct mux_chip - Represents a chip holding mux controllers. 57 * @controllers: Number of mux controllers handled by the chip. 58 * @mux: Array of mux controllers that are handled. 59 * @dev: Device structure. 60 * @id: Used to identify the device internally. 61 * @ops: Mux controller operations. 62 */ 63 struct mux_chip { 64 unsigned int controllers; 65 struct mux_control *mux; 66 struct device dev; 67 int id; 68 69 const struct mux_control_ops *ops; 70 }; 71 72 #define to_mux_chip(x) container_of((x), struct mux_chip, dev) 73 74 /** 75 * mux_chip_priv() - Get the extra memory reserved by mux_chip_alloc(). 76 * @mux_chip: The mux-chip to get the private memory from. 77 * 78 * Return: Pointer to the private memory reserved by the allocator. 79 */ 80 static inline void *mux_chip_priv(struct mux_chip *mux_chip) 81 { 82 return &mux_chip->mux[mux_chip->controllers]; 83 } 84 85 struct mux_chip *mux_chip_alloc(struct device *dev, 86 unsigned int controllers, size_t sizeof_priv); 87 int mux_chip_register(struct mux_chip *mux_chip); 88 void mux_chip_unregister(struct mux_chip *mux_chip); 89 void mux_chip_free(struct mux_chip *mux_chip); 90 91 struct mux_chip *devm_mux_chip_alloc(struct device *dev, 92 unsigned int controllers, 93 size_t sizeof_priv); 94 int devm_mux_chip_register(struct device *dev, struct mux_chip *mux_chip); 95 96 /** 97 * mux_control_get_index() - Get the index of the given mux controller 98 * @mux: The mux-control to get the index for. 99 * 100 * Return: The index of the mux controller within the mux chip the mux 101 * controller is a part of. 102 */ 103 static inline unsigned int mux_control_get_index(struct mux_control *mux) 104 { 105 return mux - mux->chip->mux; 106 } 107 108 #endif /* _LINUX_MUX_DRIVER_H */ 109