diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-mux | 16 | ||||
| -rw-r--r-- | Documentation/driver-model/devres.txt | 5 | ||||
| -rw-r--r-- | MAINTAINERS | 3 | ||||
| -rw-r--r-- | drivers/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/Makefile | 1 | ||||
| -rw-r--r-- | drivers/mux/Kconfig | 16 | ||||
| -rw-r--r-- | drivers/mux/Makefile | 5 | ||||
| -rw-r--r-- | drivers/mux/mux-core.c | 547 | ||||
| -rw-r--r-- | include/linux/mux/consumer.h | 32 | ||||
| -rw-r--r-- | include/linux/mux/driver.h | 108 |
10 files changed, 735 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-mux b/Documentation/ABI/testing/sysfs-class-mux new file mode 100644 index 000000000000..8715f9c7bd4f --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-mux @@ -0,0 +1,16 @@ +What: /sys/class/mux/ +Date: April 2017 +KernelVersion: 4.13 +Contact: Peter Rosin <peda@axentia.se> +Description: + The mux/ class sub-directory belongs to the Generic MUX + Framework and provides a sysfs interface for using MUX + controllers. + +What: /sys/class/mux/muxchipN/ +Date: April 2017 +KernelVersion: 4.13 +Contact: Peter Rosin <peda@axentia.se> +Description: + A /sys/class/mux/muxchipN directory is created for each + probed MUX chip where N is a simple enumeration. diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index af08b4cd7968..40e4787c399c 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -337,6 +337,11 @@ MEM MFD devm_mfd_add_devices() +MUX + devm_mux_chip_alloc() + devm_mux_chip_register() + devm_mux_control_get() + PER-CPU MEM devm_alloc_percpu() devm_free_percpu() diff --git a/MAINTAINERS b/MAINTAINERS index b2cc32caabb9..a507bb4316ce 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8719,8 +8719,11 @@ F: include/linux/spi/mmc_spi.h MULTIPLEXER SUBSYSTEM M: Peter Rosin <peda@axentia.se> S: Maintained +F: Documentation/ABI/testing/mux/sysfs-class-mux* F: Documentation/devicetree/bindings/mux/ F: include/linux/dt-bindings/mux/ +F: include/linux/mux/ +F: drivers/mux/ MULTISOUND SOUND DRIVER M: Andrew Veliath <andrewtv@usa.net> diff --git a/drivers/Kconfig b/drivers/Kconfig index ba2901e76769..505c676fa9c7 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -206,4 +206,6 @@ source "drivers/fsi/Kconfig" source "drivers/tee/Kconfig" +source "drivers/mux/Kconfig" + endmenu diff --git a/drivers/Makefile b/drivers/Makefile index cfabd141dba2..dfdcda00bfe3 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -181,3 +181,4 @@ obj-$(CONFIG_NVMEM) += nvmem/ obj-$(CONFIG_FPGA) += fpga/ obj-$(CONFIG_FSI) += fsi/ obj-$(CONFIG_TEE) += tee/ +obj-$(CONFIG_MULTIPLEXER) += mux/ diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig new file mode 100644 index 000000000000..23ab2cde83b1 --- /dev/null +++ b/drivers/mux/Kconfig @@ -0,0 +1,16 @@ +# +# Multiplexer devices +# + +menuconfig MULTIPLEXER + tristate "Multiplexer subsystem" + help + Multiplexer controller subsystem. Multiplexers are used in a + variety of settings, and this subsystem abstracts their use + so that the rest of the kernel sees a common interface. When + multiple parallel multiplexers are controlled by one single + multiplexer controller, this subsystem also coordinates the + multiplexer accesses. + + To compile the subsystem as a module, choose M here: the module will + be called mux-core. diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile new file mode 100644 index 000000000000..09f0299e109d --- /dev/null +++ b/drivers/mux/Makefile @@ -0,0 +1,5 @@ +# +# Makefile for multiplexer devices. +# + +obj-$(CONFIG_MULTIPLEXER) += mux-core.o diff --git a/drivers/mux/mux-core.c b/drivers/mux/mux-core.c new file mode 100644 index 000000000000..90b8995f07cb --- /dev/null +++ b/drivers/mux/mux-core.c @@ -0,0 +1,547 @@ +/* + * Multiplexer subsystem + * + * 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. + */ + +#define pr_fmt(fmt) "mux-core: " fmt + +#include <linux/device.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/idr.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mux/consumer.h> +#include <linux/mux/driver.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/slab.h> + +/* + * The idle-as-is "state" is not an actual state that may be selected, it + * only implies that the state should not be changed. So, use that state + * as indication that the cached state of the multiplexer is unknown. + */ +#define MUX_CACHE_UNKNOWN MUX_IDLE_AS_IS + +static struct class mux_class = { + .name = "mux", + .owner = THIS_MODULE, +}; + +static DEFINE_IDA(mux_ida); + +static int __init mux_init(void) +{ + ida_init(&mux_ida); + return class_register(&mux_class); +} + +static void __exit mux_exit(void) +{ + class_register(&mux_class); + ida_destroy(&mux_ida); +} + +static void mux_chip_release(struct device *dev) +{ + struct mux_chip *mux_chip = to_mux_chip(dev); + + ida_simple_remove(&mux_ida, mux_chip->id); + kfree(mux_chip); +} + +static struct device_type mux_type = { + .name = "mux-chip", + .release = mux_chip_release, +}; + +/** + * mux_chip_alloc() - Allocate a mux-chip. + * @dev: The parent device implementing the mux interface. + * @controllers: The number of mux controllers to allocate for this chip. + * @sizeof_priv: Size of extra memory area for private use by the caller. + * + * After allocating the mux-chip with the desired number of mux controllers + * but before registering the chip, the mux driver is required to configure + * the number of valid mux states in the mux_chip->mux[N].states members and + * the desired idle state in the returned mux_chip->mux[N].idle_state members. + * The default idle state is MUX_IDLE_AS_IS. The mux driver also needs to + * provide a pointer to the operations struct in the mux_chip->ops member + * before registering the mux-chip with mux_chip_register. + * + * Return: A pointer to the new mux-chip, or an ERR_PTR with a negative errno. + */ +struct mux_chip *mux_chip_alloc(struct device *dev, + unsigned int controllers, size_t sizeof_priv) +{ + struct mux_chip *mux_chip; + int i; + + if (WARN_ON(!dev || !controllers)) + return ERR_PTR(-EINVAL); + + mux_chip = kzalloc(sizeof(*mux_chip) + + controllers * sizeof(*mux_chip->mux) + + sizeof_priv, GFP_KERNEL); + if (!mux_chip) + return ERR_PTR(-ENOMEM); + + mux_chip->mux = (struct mux_control *)(mux_chip + 1); + mux_chip->dev.class = &mux_class; + mux_chip->dev.type = &mux_type; + mux_chip->dev.parent = dev; + mux_chip->dev.of_node = dev->of_node; + dev_set_drvdata(&mux_chip->dev, mux_chip); + + mux_chip->id = ida_simple_get(&mux_ida, 0, 0, GFP_KERNEL); + if (mux_chip->id < 0) { + int err = mux_chip->id; + + pr_err("muxchipX failed to get a device id\n"); + kfree(mux_chip); + return ERR_PTR(err); + } + dev_set_name(&mux_chip->dev, "muxchip%d", mux_chip->id); + + mux_chip->controllers = controllers; + for (i = 0; i < controllers; ++i) { + struct mux_control *mux = &mux_chip->mux[i]; + + mux->chip = mux_chip; + sema_init(&mux->lock, 1); + mux->cached_state = MUX_CACHE_UNKNOWN; + mux->idle_state = MUX_IDLE_AS_IS; + } + + device_initialize(&mux_chip->dev); + + return mux_chip; +} +EXPORT_SYMBOL_GPL(mux_chip_alloc); + +static int mux_control_set(struct mux_control *mux, int state) +{ + int ret = mux->chip->ops->set(mux, state); + + mux->cached_state = ret < 0 ? MUX_CACHE_UNKNOWN : state; + + return ret; +} + +/** + * mux_chip_register() - Register a mux-chip, thus readying the controllers + * for use. + * @mux_chip: The mux-chip to register. + * + * Do not retry registration of the same mux-chip on failure. You should + * instead put it away with mux_chip_free() and allocate a new one, if you + * for some reason would like to retry registration. + * + * Return: Zero on success or a negative errno on error. + */ +int mux_chip_register(struct mux_chip *mux_chip) +{ + int i; + int ret; + + for (i = 0; i < mux_chip->controllers; ++i) { + struct mux_control *mux = &mux_chip->mux[i]; + + if (mux->idle_state == mux->cached_state) + continue; + + ret = mux_control_set(mux, mux->idle_state); + if (ret < 0) { + dev_err(&mux_chip->dev, "unable to set idle state\n"); + return ret; + } + } + + ret = device_add(&mux_chip->dev); + if (ret < 0) + dev_err(&mux_chip->dev, + "device_add failed in %s: %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL_GPL(mux_chip_register); + +/** + * mux_chip_unregister() - Take the mux-chip off-line. + * @mux_chip: The mux-chip to unregister. + * + * mux_chip_unregister() reverses the effects of mux_chip_register(). + * But not completely, you should not try to call mux_chip_register() + * on a mux-chip that has been registered before. + */ +void mux_chip_unregister(struct mux_chip *mux_chip) +{ + device_del(&mux_chip->dev); +} +EXPORT_SYMBOL_GPL(mux_chip_unregister); + +/** + * mux_chip_free() - Free the mux-chip for good. + * @mux_chip: The mux-chip to free. + * + * mux_chip_free() reverses the effects of mux_chip_alloc(). + */ +void mux_chip_free(struct mux_chip *mux_chip) +{ + if (!mux_chip) + return; + + put_device(&mux_chip->dev); +} +EXPORT_SYMBOL_GPL(mux_chip_free); + +static void devm_mux_chip_release(struct device *dev, void *res) +{ + struct mux_chip *mux_chip = *(struct mux_chip **)res; + + mux_chip_free(mux_chip); +} + +/** + * devm_mux_chip_alloc() - Resource-managed version of mux_chip_alloc(). + * @dev: The parent device implementing the mux interface. + * @controllers: The number of mux controllers to allocate for this chip. + * @sizeof_priv: Size of extra memory area for private use by the caller. + * + * See mux_chip_alloc() for more details. + * + * Return: A pointer to the new mux-chip, or an ERR_PTR with a negative errno. + */ +struct mux_chip *devm_mux_chip_alloc(struct device *dev, + unsigned int controllers, + size_t sizeof_priv) +{ + struct mux_chip **ptr, *mux_chip; + + ptr = devres_alloc(devm_mux_chip_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + mux_chip = mux_chip_alloc(dev, controllers, sizeof_priv); + if (IS_ERR(mux_chip)) { + devres_free(ptr); + return mux_chip; + } + + *ptr = mux_chip; + devres_add(dev, ptr); + + return mux_chip; +} +EXPORT_SYMBOL_GPL(devm_mux_chip_alloc); + +static void devm_mux_chip_reg_release(struct device *dev, void *res) +{ + struct mux_chip *mux_chip = *(struct mux_chip **)res; + + mux_chip_unregister(mux_chip); +} + +/** + * devm_mux_chip_register() - Resource-managed version mux_chip_register(). + * @dev: The parent device implementing the mux interface. + * @mux_chip: The mux-chip to register. + * + * See mux_chip_register() for more details. + * + * Return: Zero on success or a negative errno on error. + */ +int devm_mux_chip_register(struct device *dev, + struct mux_chip *mux_chip) +{ + struct mux_chip **ptr; + int res; + + ptr = devres_alloc(devm_mux_chip_reg_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + res = mux_chip_register(mux_chip); + if (res) { + devres_free(ptr); + return res; + } + + *ptr = mux_chip; + devres_add(dev, ptr); + + return res; +} +EXPORT_SYMBOL_GPL(devm_mux_chip_register); + +/** + * mux_control_states() - Query the number of multiplexer states. + * @mux: The mux-control to query. + * + * Return: The number of multiplexer states. + */ +unsigned int mux_control_states(struct mux_control *mux) +{ + return mux->states; +} +EXPORT_SYMBOL_GPL(mux_control_states); + +/* + * The mux->lock must be down when calling this function. + */ +static int __mux_control_select(struct mux_control *mux, int state) +{ + int ret; + + if (WARN_ON(state < 0 || state >= mux->states)) + return -EINVAL; + + if (mux->cached_state == state) + return 0; + + ret = mux_control_set(mux, state); + if (ret >= 0) + return 0; + + /* The mux update failed, try to revert if appropriate... */ + if (mux->idle_state != MUX_IDLE_AS_IS) + mux_control_set(mux, mux->idle_state); + + return ret; +} + +/** + * mux_control_select() - Select the given multiplexer state. + * @mux: The mux-control to request a change of state from. + * @state: The new requested state. + * + * On successfully selecting the mux-control state, it will be locked until + * there is a call to mux_control_deselect(). If the mux-control is already + * selected when mux_control_select() is called, the caller will be blocked + * until mux_control_deselect() is called (by someone else). + * + * Therefore, make sure to call mux_control_deselect() when the operation is + * complete and the mux-control is free for others to use, but do not call + * mux_control_deselect() if mux_control_select() fails. + * + * Return: 0 when the mux-control state has the requested state or a negative + * errno on error. + */ +int mux_control_select(struct mux_control *mux, unsigned int state) +{ + int ret; + + ret = down_killable(&mux->lock); + if (ret < 0) + return ret; + + ret = __mux_control_select(mux, state); + + if (ret < 0) + up(&mux->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(mux_control_select); + +/** + * mux_control_try_select() - Try to select the given multiplexer state. + * @mux: The mux-control to request a change of state from. + * @state: The new requested state. + * + * On successfully selecting the mux-control state, it will be locked until + * mux_control_deselect() called. + * + * Therefore, make sure to call mux_control_deselect() when the operation is + * complete and the mux-control is free for others to use, but do not call + * mux_control_deselect() if mux_control_try_select() fails. + * + * Return: 0 when the mux-control state has the requested state or a negative + * errno on error. Specifically -EBUSY if the mux-control is contended. + */ +int mux_control_try_select(struct mux_control *mux, unsigned int state) +{ + int ret; + + if (down_trylock(&mux->lock)) + return -EBUSY; + + ret = __mux_control_select(mux, state); + + if (ret < 0) + up(&mux->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(mux_control_try_select); + +/** + * mux_control_deselect() - Deselect the previously selected multiplexer state. + * @mux: The mux-control to deselect. + * + * It is required that a single call is made to mux_control_deselect() for + * each and every successful call made to either of mux_control_select() or + * mux_control_try_select(). + * + * Return: 0 on success and a negative errno on error. An error can only + * occur if the mux has an idle state. Note that even if an error occurs, the + * mux-control is unlocked and is thus free for the next access. + */ +int mux_control_deselect(struct mux_control *mux) +{ + int ret = 0; + + if (mux->idle_state != MUX_IDLE_AS_IS && + mux->idle_state != mux->cached_state) + ret = mux_control_set(mux, mux->idle_state); + + up(&mux->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(mux_control_deselect); + +static int of_dev_node_match(struct device *dev, const void *data) +{ + return dev->of_node == data; +} + +static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np) +{ + struct device *dev; + + dev = class_find_device(&mux_class, NULL, np, of_dev_node_match); + + return dev ? to_mux_chip(dev) : NULL; +} + +/** + * mux_control_get() - Get the mux-control for a device. + * @dev: The device that needs a mux-control. + * @mux_name: The name identifying the mux-control. + * + * Return: A pointer to the mux-control, or an ERR_PTR with a negative errno. + */ +struct mux_control *mux_control_get(struct device *dev, const char *mux_name) +{ + struct device_node *np = dev->of_node; + struct of_phandle_args args; + struct mux_chip *mux_chip; + unsigned int controller; + int index = 0; + int ret; + + if (mux_name) { + index = of_property_match_string(np, "mux-control-names", + mux_name); + if (index < 0) { + dev_err(dev, "mux controller '%s' not found\n", + mux_name); + return ERR_PTR(index); + } + } + + ret = of_parse_phandle_with_args(np, + "mux-controls", "#mux-control-cells", + index, &args); + if (ret) { + dev_err(dev, "%s: failed to get mux-control %s(%i)\n", + np->full_name, mux_name ?: "", index); + return ERR_PTR(ret); + } + + mux_chip = of_find_mux_chip_by_node(args.np); + of_node_put(args.np); + if (!mux_chip) + return ERR_PTR(-EPROBE_DEFER); + + if (args.args_count > 1 || + (!args.args_count && (mux_chip->controllers > 1))) { + dev_err(dev, "%s: wrong #mux-control-cells for %s\n", + np->full_name, args.np->full_name); + return ERR_PTR(-EINVAL); + } + + controller = 0; + if (args.args_count) + controller = args.args[0]; + + if (controller >= mux_chip->controllers) { + dev_err(dev, "%s: bad mux controller %u specified in %s\n", + np->full_name, controller, args.np->full_name); + return ERR_PTR(-EINVAL); + } + + get_device(&mux_chip->dev); + return &mux_chip->mux[controller]; +} +EXPORT_SYMBOL_GPL(mux_control_get); + +/** + * mux_control_put() - Put away the mux-control for good. + * @mux: The mux-control to put away. + * + * mux_control_put() reverses the effects of mux_control_get(). + */ +void mux_control_put(struct mux_control *mux) +{ + put_device(&mux->chip->dev); +} +EXPORT_SYMBOL_GPL(mux_control_put); + +static void devm_mux_control_release(struct device *dev, void *res) +{ + struct mux_control *mux = *(struct mux_control **)res; + + mux_control_put(mux); +} + +/** + * devm_mux_control_get() - Get the mux-control for a device, with resource + * management. + * @dev: The device that needs a mux-control. + * @mux_name: The name identifying the mux-control. + * + * Return: Pointer to the mux-control, or an ERR_PTR with a negative errno. + */ +struct mux_control *devm_mux_control_get(struct device *dev, + const char *mux_name) +{ + struct mux_control **ptr, *mux; + + ptr = devres_alloc(devm_mux_control_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + mux = mux_control_get(dev, mux_name); + if (IS_ERR(mux)) { + devres_free(ptr); + return mux; + } + + *ptr = mux; + devres_add(dev, ptr); + + return mux; +} +EXPORT_SYMBOL_GPL(devm_mux_control_get); + +/* + * Using subsys_initcall instead of module_init here to try to ensure - for + * the non-modular case - that the subsystem is initialized when mux consumers + * and mux controllers start to use it. + * For the modular case, the ordering is ensured with module dependencies. + */ +subsys_initcall(mux_init); +module_exit(mux_exit); + +MODULE_DESCRIPTION("Multiplexer subsystem"); +MODULE_AUTHOR("Peter Rosin <peda@axentia.se>"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/mux/consumer.h b/include/linux/mux/consumer.h new file mode 100644 index 000000000000..5577e1b773c4 --- /dev/null +++ b/include/linux/mux/consumer.h @@ -0,0 +1,32 @@ +/* + * mux/consumer.h - definitions for the multiplexer consumer 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_CONSUMER_H +#define _LINUX_MUX_CONSUMER_H + +struct device; +struct mux_control; + +unsigned int mux_control_states(struct mux_control *mux); +int __must_check mux_control_select(struct mux_control *mux, + unsigned int state); +int __must_check mux_control_try_select(struct mux_control *mux, + unsigned int state); +int mux_control_deselect(struct mux_control *mux); + +struct mux_control *mux_control_get(struct device *dev, const char *mux_name); +void mux_control_put(struct mux_control *mux); + +struct mux_control *devm_mux_control_get(struct device *dev, + const char *mux_name); + +#endif /* _LINUX_MUX_CONSUMER_H */ 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 */ |