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Diffstat (limited to 'include/linux/mux/driver.h')
-rw-r--r-- | include/linux/mux/driver.h | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/include/linux/mux/driver.h b/include/linux/mux/driver.h new file mode 100644 index 000000000000..35c3579c3304 --- /dev/null +++ b/include/linux/mux/driver.h @@ -0,0 +1,108 @@ +/* + * mux/driver.h - definitions for the multiplexer driver interface + * + * Copyright (C) 2017 Axentia Technologies AB + * + * Author: Peter Rosin <peda@axentia.se> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _LINUX_MUX_DRIVER_H +#define _LINUX_MUX_DRIVER_H + +#include <dt-bindings/mux/mux.h> +#include <linux/device.h> +#include <linux/semaphore.h> + +struct mux_chip; +struct mux_control; + +/** + * struct mux_control_ops - Mux controller operations for a mux chip. + * @set: Set the state of the given mux controller. + */ +struct mux_control_ops { + int (*set)(struct mux_control *mux, int state); +}; + +/** + * struct mux_control - Represents a mux controller. + * @lock: Protects the mux controller state. + * @chip: The mux chip that is handling this mux controller. + * @cached_state: The current mux controller state, or -1 if none. + * @states: The number of mux controller states. + * @idle_state: The mux controller state to use when inactive, or one + * of MUX_IDLE_AS_IS and MUX_IDLE_DISCONNECT. + * + * Mux drivers may only change @states and @idle_state, and may only do so + * between allocation and registration of the mux controller. Specifically, + * @cached_state is internal to the mux core and should never be written by + * mux drivers. + */ +struct mux_control { + struct semaphore lock; /* protects the state of the mux */ + + struct mux_chip *chip; + int cached_state; + + unsigned int states; + int idle_state; +}; + +/** + * struct mux_chip - Represents a chip holding mux controllers. + * @controllers: Number of mux controllers handled by the chip. + * @mux: Array of mux controllers that are handled. + * @dev: Device structure. + * @id: Used to identify the device internally. + * @ops: Mux controller operations. + */ +struct mux_chip { + unsigned int controllers; + struct mux_control *mux; + struct device dev; + int id; + + const struct mux_control_ops *ops; +}; + +#define to_mux_chip(x) container_of((x), struct mux_chip, dev) + +/** + * mux_chip_priv() - Get the extra memory reserved by mux_chip_alloc(). + * @mux_chip: The mux-chip to get the private memory from. + * + * Return: Pointer to the private memory reserved by the allocator. + */ +static inline void *mux_chip_priv(struct mux_chip *mux_chip) +{ + return &mux_chip->mux[mux_chip->controllers]; +} + +struct mux_chip *mux_chip_alloc(struct device *dev, + unsigned int controllers, size_t sizeof_priv); +int mux_chip_register(struct mux_chip *mux_chip); +void mux_chip_unregister(struct mux_chip *mux_chip); +void mux_chip_free(struct mux_chip *mux_chip); + +struct mux_chip *devm_mux_chip_alloc(struct device *dev, + unsigned int controllers, + size_t sizeof_priv); +int devm_mux_chip_register(struct device *dev, struct mux_chip *mux_chip); + +/** + * mux_control_get_index() - Get the index of the given mux controller + * @mux: The mux-control to get the index for. + * + * Return: The index of the mux controller within the mux chip the mux + * controller is a part of. + */ +static inline unsigned int mux_control_get_index(struct mux_control *mux) +{ + return mux - mux->chip->mux; +} + +#endif /* _LINUX_MUX_DRIVER_H */ |