diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/dm/uclass-id.h | 1 | ||||
| -rw-r--r-- | include/dt-bindings/mux/mux.h | 17 | ||||
| -rw-r--r-- | include/mux-internal.h | 109 | ||||
| -rw-r--r-- | include/mux.h | 147 |
4 files changed, 274 insertions, 0 deletions
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index 88f10c4622..17542de2f3 100644 --- a/include/dm/uclass-id.h +++ b/include/dm/uclass-id.h @@ -71,6 +71,7 @@ enum uclass_id { UCLASS_MMC, /* SD / MMC card or chip */ UCLASS_MOD_EXP, /* RSA Mod Exp device */ UCLASS_MTD, /* Memory Technology Device (MTD) device */ + UCLASS_MUX, /* Multiplexer device */ UCLASS_NOP, /* No-op devices */ UCLASS_NORTHBRIDGE, /* Intel Northbridge / SDRAM controller */ UCLASS_NVME, /* NVM Express device */ diff --git a/include/dt-bindings/mux/mux.h b/include/dt-bindings/mux/mux.h new file mode 100644 index 0000000000..042719218d --- /dev/null +++ b/include/dt-bindings/mux/mux.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * This header provides constants for most Multiplexer bindings. + * + * Most Multiplexer bindings specify an idle state. In most cases, the + * the multiplexer can be left as is when idle, and in some cases it can + * disconnect the input/output and leave the multiplexer in a high + * impedance state. + */ + +#ifndef _DT_BINDINGS_MUX_MUX_H +#define _DT_BINDINGS_MUX_MUX_H + +#define MUX_IDLE_AS_IS (-1) +#define MUX_IDLE_DISCONNECT (-2) + +#endif diff --git a/include/mux-internal.h b/include/mux-internal.h new file mode 100644 index 0000000000..93e3a5cdd7 --- /dev/null +++ b/include/mux-internal.h @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Based on the linux multiplexer framework + * + * Copyright (C) 2017 Axentia Technologies AB + * Author: Peter Rosin <peda@axentia.se> + * + * Copyright (C) 2017-2018 Texas Instruments Incorporated - http://www.ti.com/ + * Jean-Jacques Hiblot <jjhiblot@ti.com> + */ + +#ifndef _MUX_INTERNAL_H +#define _MUX_INTERNAL_H + +/* See mux.h for background documentation. */ + +struct ofnode_phandle_args; + +/** + * 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. + * + * This a per-device uclass-private data. + */ +struct mux_chip { + unsigned int controllers; + struct mux_control *mux; +}; + +/** + * struct mux_control_ops - Mux controller operations for a mux chip. + * @set: Set the state of the given mux controller. + */ +struct mux_control_ops { + /** + * set - Apply a state to a multiplexer control + * + * @mux: A multiplexer control + * @return 0 if OK, or a negative error code. + */ + int (*set)(struct mux_control *mux, int state); + + /** + * of_xlate - Translate a client's device-tree (OF) multiplexer + * specifier. + * + * If this function pointer is set to NULL, the multiplexer core will + * use a default implementation, which assumes #mux-control-cells = <1> + * and that the DT cell contains a simple integer channel ID. + * + * @dev_mux: The multiplexer device. A single device may handle + * several multiplexer controls. + * @args: The multiplexer specifier values from device tree. + * @muxp: (out) A multiplexer control + * @return 0 if OK, or a negative error code. + */ + int (*of_xlate)(struct mux_chip *dev_mux, + struct ofnode_phandle_args *args, + struct mux_control **muxp); +}; + +/** + * struct mux_control - Represents a mux controller. + * @in_use: Whether the mux controller is in use or not. + * @dev: The client device. + * @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. + * @id: The index of the mux controller within the mux chip + * it is a part of. + * + * 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 { + bool in_use; + struct udevice *dev; + int cached_state; + unsigned int states; + int idle_state; + int id; +}; + +/** + * 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->id; +} + +/** + * mux_alloc_controllers() - Allocate the given number of mux controllers. + * @dev: The client device. + * controllers: Number of controllers to allocate. + * + * Return: 0 of OK, -errno otherwise. + */ +int mux_alloc_controllers(struct udevice *dev, unsigned int controllers); + +#endif diff --git a/include/mux.h b/include/mux.h new file mode 100644 index 0000000000..85eb7d42fc --- /dev/null +++ b/include/mux.h @@ -0,0 +1,147 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Based on the linux multiplexer framework + * + * At its core, a multiplexer (or mux), also known as a data selector, is a + * device that selects between several analog or digital input signals and + * forwards it to a single output line. This notion can be extended to work + * with buses, like a I2C bus multiplexer for example. + * + * Copyright (C) 2017 Axentia Technologies AB + * Author: Peter Rosin <peda@axentia.se> + * + * Copyright (C) 2017-2018 Texas Instruments Incorporated - http://www.ti.com/ + * Jean-Jacques Hiblot <jjhiblot@ti.com> + */ + +#ifndef _MUX_H_ +#define _MUX_H_ + +#include <linux/errno.h> +#include <linux/types.h> + +struct udevice; +struct mux_control; + +#if CONFIG_IS_ENABLED(MULTIPLEXER) +/** + * 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); + +/** + * 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 function will indicate + * -EBUSY + * + * 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 __must_check mux_control_select(struct mux_control *mux, + unsigned int state); +#define mux_control_try_select(mux) mux_control_select(mux) + +/** + * 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); + +/** + * mux_get_by_index() = Get a mux by integer index. + * @dev: The client device. + * @index: The index of the mux to get. + * @mux: A pointer to the 'mux_control' struct to initialize. + * + * This looks up and initializes a mux. The index is relative to the client + * device. + * + * Return: 0 if OK, or a negative error code. + */ +int mux_get_by_index(struct udevice *dev, int index, struct mux_control **mux); + +/** + * 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. + * @mux: A pointer to the mux-control pointer. + * + * Return: 0 of OK, or a negative error code. + */ +int mux_control_get(struct udevice *dev, const char *name, + struct mux_control **mux); + +/** + * 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); + +/** + * 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 udevice *dev, + const char *mux_name); +#else +unsigned int mux_control_states(struct mux_control *mux) +{ + return -ENOSYS; +} + +int __must_check mux_control_select(struct mux_control *mux, + unsigned int state) +{ + return -ENOSYS; +} + +#define mux_control_try_select(mux) mux_control_select(mux) + +int mux_control_deselect(struct mux_control *mux) +{ + return -ENOSYS; +} + +struct mux_control *mux_control_get(struct udevice *dev, const char *mux_name) +{ + return NULL; +} + +void mux_control_put(struct mux_control *mux) +{ +} + +struct mux_control *devm_mux_control_get(struct udevice *dev, + const char *mux_name) +{ + return NULL; +} +#endif + +#endif |