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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150/* SPDX-License-Identifier: GPL-2.0 *//* * I2C Address Translator * * Copyright (c) 2019,2022 Luca Ceresoli <luca@lucaceresoli.net> * Copyright (c) 2022,2023 Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> * * Based on i2c-mux.h */
#ifndef _LINUX_I2C_ATR_H#define _LINUX_I2C_ATR_H
#include <linux/i2c.h>#include <linux/types.h>
struct device;struct fwnode_handle;struct i2c_atr;
/** * enum i2c_atr_flags - Flags for an I2C ATR driver * * @I2C_ATR_F_STATIC: ATR does not support dynamic mapping, use static mapping. * Mappings will only be added or removed as a result of * devices being added or removed from a child bus. * The ATR pool will have to be big enough to accomodate all * devices expected to be added to the child buses. * @I2C_ATR_F_PASSTHROUGH: Allow unmapped incoming addresses to pass through */enum i2c_atr_flags { I2C_ATR_F_STATIC = BIT(0), I2C_ATR_F_PASSTHROUGH = BIT(1),};
/** * struct i2c_atr_ops - Callbacks from ATR to the device driver. * @attach_addr: Notify the driver of a new device connected on a child * bus, with the alias assigned to it. The driver must * configure the hardware to use the alias. * @detach_addr: Notify the driver of a device getting disconnected. The * driver must configure the hardware to stop using the * alias. * * All these functions return 0 on success, a negative error code otherwise. */struct i2c_atr_ops { int (*attach_addr)(struct i2c_atr *atr, u32 chan_id, u16 addr, u16 alias); void (*detach_addr)(struct i2c_atr *atr, u32 chan_id, u16 addr);};
/** * struct i2c_atr_adap_desc - An ATR downstream bus descriptor * @chan_id: Index of the new adapter (0 .. max_adapters-1). This value is * passed to the callbacks in `struct i2c_atr_ops`. * @parent: The device used as the parent of the new i2c adapter, or NULL * to use the i2c-atr device as the parent. * @bus_handle: The fwnode handle that points to the adapter's i2c * peripherals, or NULL. * @num_aliases: The number of aliases in this adapter's private alias pool. Set * to zero if this adapter uses the ATR's global alias pool. * @aliases: An optional array of private aliases used by the adapter * instead of the ATR's global pool of aliases. Must contain * exactly num_aliases entries if num_aliases > 0, is ignored * otherwise. */struct i2c_atr_adap_desc { u32 chan_id; struct device *parent; struct fwnode_handle *bus_handle; size_t num_aliases; u16 *aliases __counted_by_ptr(num_aliases);};
/** * i2c_atr_new() - Allocate and initialize an I2C ATR helper. * @parent: The parent (upstream) adapter * @dev: The device acting as an ATR * @ops: Driver-specific callbacks * @max_adapters: Maximum number of child adapters * @flags: Flags for ATR * * The new ATR helper is connected to the parent adapter but has no child * adapters. Call i2c_atr_add_adapter() to add some. * * Call i2c_atr_delete() to remove. * * Return: pointer to the new ATR helper object, or ERR_PTR */struct i2c_atr *i2c_atr_new(struct i2c_adapter *parent, struct device *dev, const struct i2c_atr_ops *ops, int max_adapters, u32 flags);
/** * i2c_atr_delete - Delete an I2C ATR helper. * @atr: I2C ATR helper to be deleted. * * Precondition: all the adapters added with i2c_atr_add_adapter() must be * removed by calling i2c_atr_del_adapter(). */void i2c_atr_delete(struct i2c_atr *atr);
/** * i2c_atr_add_adapter - Create a child ("downstream") I2C bus. * @atr: The I2C ATR * @desc: An ATR adapter descriptor * * After calling this function a new i2c bus will appear. Adding and removing * devices on the downstream bus will result in calls to the * &i2c_atr_ops->attach_client and &i2c_atr_ops->detach_client callbacks for the * driver to assign an alias to the device. * * The adapter's fwnode is set to @bus_handle, or if @bus_handle is NULL the * function looks for a child node whose 'reg' property matches the chan_id * under the i2c-atr device's 'i2c-atr' node. * * Call i2c_atr_del_adapter() to remove the adapter. * * Return: 0 on success, a negative error code otherwise. */int i2c_atr_add_adapter(struct i2c_atr *atr, struct i2c_atr_adap_desc *desc);
/** * i2c_atr_del_adapter - Remove a child ("downstream") I2C bus added by * i2c_atr_add_adapter(). If no I2C bus has been added * this function is a no-op. * @atr: The I2C ATR * @chan_id: Index of the adapter to be removed (0 .. max_adapters-1) */void i2c_atr_del_adapter(struct i2c_atr *atr, u32 chan_id);
/** * i2c_atr_set_driver_data - Set private driver data to the i2c-atr instance. * @atr: The I2C ATR * @data: Pointer to the data to store */void i2c_atr_set_driver_data(struct i2c_atr *atr, void *data);
/** * i2c_atr_get_driver_data - Get the stored drive data. * @atr: The I2C ATR * * Return: Pointer to the stored data */void *i2c_atr_get_driver_data(struct i2c_atr *atr);
#endif /* _LINUX_I2C_ATR_H */