/* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (C) 2018 Cadence Design Systems Inc. * * Author: Boris Brezillon <boris.brezillon@bootlin.com> */ #ifndef I3C_MASTER_H #define I3C_MASTER_H #include <asm/bitsperlong.h> #include <linux/bitops.h> #include <linux/i2c.h> #include <linux/i3c/ccc.h> #include <linux/i3c/device.h> #include <linux/rwsem.h> #include <linux/spinlock.h> #include <linux/workqueue.h> #define I3C_HOT_JOIN_ADDR 0x2 #define I3C_BROADCAST_ADDR 0x7e #define I3C_MAX_ADDR GENMASK(6, 0) struct i2c_client; struct i3c_master_controller; struct i3c_bus; struct i3c_device; /** * struct i3c_i2c_dev_desc - Common part of the I3C/I2C device descriptor * @node: node element used to insert the slot into the I2C or I3C device * list * @master: I3C master that instantiated this device. Will be used to do * I2C/I3C transfers * @master_priv: master private data assigned to the device. Can be used to * add master specific information * * This structure is describing common I3C/I2C dev information. */ struct i3c_i2c_dev_desc { struct list_head node; struct i3c_master_controller *master; void *master_priv; }; #define I3C_LVR_I2C_INDEX_MASK GENMASK(7, 5) #define I3C_LVR_I2C_INDEX(x) ((x) << 5) #define I3C_LVR_I2C_FM_MODE BIT(4) #define I2C_MAX_ADDR GENMASK(6, 0) /** * struct i2c_dev_boardinfo - I2C device board information * @node: used to insert the boardinfo object in the I2C boardinfo list * @base: regular I2C board information * @lvr: LVR (Legacy Virtual Register) needed by the I3C core to know about * the I2C device limitations * * This structure is used to attach board-level information to an I2C device. * Each I2C device connected on the I3C bus should have one. */ struct i2c_dev_boardinfo { struct list_head node; struct i2c_board_info base; u8 lvr; }; /** * struct i2c_dev_desc - I2C device descriptor * @common: common part of the I2C device descriptor * @boardinfo: pointer to the boardinfo attached to this I2C device * @dev: I2C device object registered to the I2C framework * @addr: I2C device address * @lvr: LVR (Legacy Virtual Register) needed by the I3C core to know about * the I2C device limitations * * Each I2C device connected on the bus will have an i2c_dev_desc. * This object is created by the core and later attached to the controller * using &struct_i3c_master_controller->ops->attach_i2c_dev(). * * &struct_i2c_dev_desc is the internal representation of an I2C device * connected on an I3C bus. This object is also passed to all * &struct_i3c_master_controller_ops hooks. */ struct i2c_dev_desc { struct i3c_i2c_dev_desc common; struct i2c_client *dev; u16 addr; u8 lvr; }; /** * struct i3c_ibi_slot - I3C IBI (In-Band Interrupt) slot * @work: work associated to this slot. The IBI handler will be called from * there * @dev: the I3C device that has generated this IBI * @len: length of the payload associated to this IBI * @data: payload buffer * * An IBI slot is an object pre-allocated by the controller and used when an * IBI comes in. * Every time an IBI comes in, the I3C master driver should find a free IBI * slot in its IBI slot pool, retrieve the IBI payload and queue the IBI using * i3c_master_queue_ibi(). * * How IBI slots are allocated is left to the I3C master driver, though, for * simple kmalloc-based allocation, the generic IBI slot pool can be used. */ struct i3c_ibi_slot { struct work_struct work; struct i3c_dev_desc *dev; unsigned int len; void *data; }; /** * struct i3c_device_ibi_info - IBI information attached to a specific device * @all_ibis_handled: used to be informed when no more IBIs are waiting to be * processed. Used by i3c_device_disable_ibi() to wait for * all IBIs to be dequeued * @pending_ibis: count the number of pending IBIs. Each pending IBI has its * work element queued to the controller workqueue * @max_payload_len: maximum payload length for an IBI coming from this device. * this value is specified when calling * i3c_device_request_ibi() and should not change at run * time. All messages IBIs exceeding this limit should be * rejected by the master * @num_slots: number of IBI slots reserved for this device * @enabled: reflect the IBI status * @handler: IBI handler specified at i3c_device_request_ibi() call time. This * handler will be called from the controller workqueue, and as such * is allowed to sleep (though it is recommended to process the IBI * as fast as possible to not stall processing of other IBIs queued * on the same workqueue). * New I3C messages can be sent from the IBI handler * * The &struct_i3c_device_ibi_info object is allocated when * i3c_device_request_ibi() is called and attached to a specific device. This * object is here to manage IBIs coming from a specific I3C device. * * Note that this structure is the generic view of the IBI management * infrastructure. I3C master drivers may have their own internal * representation which they can associate to the device using * controller-private data. */ struct i3c_device_ibi_info { struct completion all_ibis_handled; atomic_t pending_ibis; unsigned int max_payload_len; unsigned int num_slots; unsigned int enabled; void (*handler)(struct i3c_device *dev, const struct i3c_ibi_payload *payload); }; /** * struct i3c_dev_boardinfo - I3C device board information * @node: used to insert the boardinfo object in the I3C boardinfo list * @init_dyn_addr: initial dynamic address requested by the FW. We provide no * guarantee that the device will end up using this address, * but try our best to assign this specific address to the * device * @static_addr: static address the I3C device listen on before it's been * assigned a dynamic address by the master. Will be used during * bus initialization to assign it a specific dynamic address * before starting DAA (Dynamic Address Assignment) * @pid: I3C Provisional ID exposed by the device. This is a unique identifier * that may be used to attach boardinfo to i3c_dev_desc when the device * does not have a static address * @of_node: optional DT node in case the device has been described in the DT * * This structure is used to attach board-level information to an I3C device. * Not all I3C devices connected on the bus will have a boardinfo. It's only * needed if you want to attach extra resources to a device or assign it a * specific dynamic address. */ struct i3c_dev_boardinfo { struct list_head node; u8 init_dyn_addr; u8 static_addr; u64 pid; struct device_node *of_node; }; /** * struct i3c_dev_desc - I3C device descriptor * @common: common part of the I3C device descriptor * @info: I3C device information. Will be automatically filled when you create * your device with i3c_master_add_i3c_dev_locked() * @ibi_lock: lock used to protect the &struct_i3c_device->ibi * @ibi: IBI info attached to a device. Should be NULL until * i3c_device_request_ibi() is called * @dev: pointer to the I3C device object exposed to I3C device drivers. This * should never be accessed from I3C master controller drivers. Only core * code should manipulate it in when updating the dev <-> desc link or * when propagating IBI events to the driver * @boardinfo: pointer to the boardinfo attached to this I3C device * * Internal representation of an I3C device. This object is only used by the * core and passed to I3C master controller drivers when they're requested to * do some operations on the device. * The core maintains the link between the internal I3C dev descriptor and the * object exposed to the I3C device drivers (&struct_i3c_device). */ struct i3c_dev_desc { struct i3c_i2c_dev_desc common; struct i3c_device_info info; struct mutex ibi_lock; struct i3c_device_ibi_info *ibi; struct i3c_device *dev; const struct i3c_dev_boardinfo *boardinfo; }; /** * struct i3c_device - I3C device object * @dev: device object to register the I3C dev to the device model * @desc: pointer to an i3c device descriptor object. This link is updated * every time the I3C device is rediscovered with a different dynamic * address assigned * @bus: I3C bus this device is attached to * * I3C device object exposed to I3C device drivers. The takes care of linking * this object to the relevant &struct_i3c_dev_desc one. * All I3C devs on the I3C bus are represented, including I3C masters. For each * of them, we have an instance of &struct i3c_device. */ struct i3c_device { struct device dev; struct i3c_dev_desc *desc; struct i3c_bus *bus; }; /* * The I3C specification says the maximum number of devices connected on the * bus is 11, but this number depends on external parameters like trace length, * capacitive load per Device, and the types of Devices present on the Bus. * I3C master can also have limitations, so this number is just here as a * reference and should be adjusted on a per-controller/per-board basis. */ #define I3C_BUS_MAX_DEVS 11 #define I3C_BUS_MAX_I3C_SCL_RATE 12900000 #define I3C_BUS_TYP_I3C_SCL_RATE 12500000 #define I3C_BUS_I2C_FM_PLUS_SCL_RATE 1000000 #define I3C_BUS_I2C_FM_SCL_RATE 400000 #define I3C_BUS_TLOW_OD_MIN_NS 200 /** * enum i3c_bus_mode - I3C bus mode * @I3C_BUS_MODE_PURE: only I3C devices are connected to the bus. No limitation * expected * @I3C_BUS_MODE_MIXED_FAST: I2C devices with 50ns spike filter are present on * the bus. The only impact in this mode is that the * high SCL pulse has to stay below 50ns to trick I2C * devices when transmitting I3C frames * @I3C_BUS_MODE_MIXED_LIMITED: I2C devices without 50ns spike filter are * present on the bus. However they allow * compliance up to the maximum SDR SCL clock * frequency. * @I3C_BUS_MODE_MIXED_SLOW: I2C devices without 50ns spike filter are present * on the bus */ enum i3c_bus_mode { I3C_BUS_MODE_PURE, I3C_BUS_MODE_MIXED_FAST, I3C_BUS_MODE_MIXED_LIMITED, I3C_BUS_MODE_MIXED_SLOW, }; /** * enum i3c_addr_slot_status - I3C address slot status * @I3C_ADDR_SLOT_FREE: address is free * @I3C_ADDR_SLOT_RSVD: address is reserved * @I3C_ADDR_SLOT_I2C_DEV: address is assigned to an I2C device * @I3C_ADDR_SLOT_I3C_DEV: address is assigned to an I3C device * @I3C_ADDR_SLOT_STATUS_MASK: address slot mask * * On an I3C bus, addresses are assigned dynamically, and we need to know which * addresses are free to use and which ones are already assigned. * * Addresses marked as reserved are those reserved by the I3C protocol * (broadcast address, ...). */ enum i3c_addr_slot_status { I3C_ADDR_SLOT_FREE, I3C_ADDR_SLOT_RSVD, I3C_ADDR_SLOT_I2C_DEV, I3C_ADDR_SLOT_I3C_DEV, I3C_ADDR_SLOT_STATUS_MASK = 3, }; /** * struct i3c_bus - I3C bus object * @cur_master: I3C master currently driving the bus. Since I3C is multi-master * this can change over the time. Will be used to let a master * know whether it needs to request bus ownership before sending * a frame or not * @id: bus ID. Assigned by the framework when register the bus * @addrslots: a bitmap with 2-bits per-slot to encode the address status and * ease the DAA (Dynamic Address Assignment) procedure (see * &enum i3c_addr_slot_status) * @mode: bus mode (see &enum i3c_bus_mode) * @scl_rate.i3c: maximum rate for the clock signal when doing I3C SDR/priv * transfers * @scl_rate.i2c: maximum rate for the clock signal when doing I2C transfers * @scl_rate: SCL signal rate for I3C and I2C mode * @devs.i3c: contains a list of I3C device descriptors representing I3C * devices connected on the bus and successfully attached to the * I3C master * @devs.i2c: contains a list of I2C device descriptors representing I2C * devices connected on the bus and successfully attached to the * I3C master * @devs: 2 lists containing all I3C/I2C devices connected to the bus * @lock: read/write lock on the bus. This is needed to protect against * operations that have an impact on the whole bus and the devices * connected to it. For example, when asking slaves to drop their * dynamic address (RSTDAA CCC), we need to make sure no one is trying * to send I3C frames to these devices. * Note that this lock does not protect against concurrency between * devices: several drivers can send different I3C/I2C frames through * the same master in parallel. This is the responsibility of the * master to guarantee that frames are actually sent sequentially and * not interlaced * * The I3C bus is represented with its own object and not implicitly described * by the I3C master to cope with the multi-master functionality, where one bus * can be shared amongst several masters, each of them requesting bus ownership * when they need to. */ struct i3c_bus { struct i3c_dev_desc *cur_master; int id; unsigned long addrslots[((I2C_MAX_ADDR + 1) * 2) / BITS_PER_LONG]; enum i3c_bus_mode mode; struct { unsigned long i3c; unsigned long i2c; } scl_rate; struct { struct list_head i3c; struct list_head i2c; } devs; struct rw_semaphore lock; }; /** * struct i3c_master_controller_ops - I3C master methods * @bus_init: hook responsible for the I3C bus initialization. You should at * least call master_set_info() from there and set the bus mode. * You can also put controller specific initialization in there. * This method is mandatory. * @bus_cleanup: cleanup everything done in * &i3c_master_controller_ops->bus_init(). * This method is optional. * @attach_i3c_dev: called every time an I3C device is attached to the bus. It * can be after a DAA or when a device is statically declared * by the FW, in which case it will only have a static address * and the dynamic address will be 0. * When this function is called, device information have not * been retrieved yet. * This is a good place to attach master controller specific * data to I3C devices. * This method is optional. * @reattach_i3c_dev: called every time an I3C device has its addressed * changed. It can be because the device has been powered * down and has lost its address, or it can happen when a * device had a static address and has been assigned a * dynamic address with SETDASA. * This method is optional. * @detach_i3c_dev: called when an I3C device is detached from the bus. Usually * happens when the master device is unregistered. * This method is optional. * @do_daa: do a DAA (Dynamic Address Assignment) procedure. This is procedure * should send an ENTDAA CCC command and then add all devices * discovered sure the DAA using i3c_master_add_i3c_dev_locked(). * Add devices added with i3c_master_add_i3c_dev_locked() will then be * attached or re-attached to the controller. * This method is mandatory. * @supports_ccc_cmd: should return true if the CCC command is supported, false * otherwise. * This method is optional, if not provided the core assumes * all CCC commands are supported. * @send_ccc_cmd: send a CCC command * This method is mandatory. * @priv_xfers: do one or several private I3C SDR transfers * This method is mandatory. * @attach_i2c_dev: called every time an I2C device is attached to the bus. * This is a good place to attach master controller specific * data to I2C devices. * This method is optional. * @detach_i2c_dev: called when an I2C device is detached from the bus. Usually * happens when the master device is unregistered. * This method is optional. * @i2c_xfers: do one or several I2C transfers. Note that, unlike i3c * transfers, the core does not guarantee that buffers attached to * the transfers are DMA-safe. If drivers want to have DMA-safe * buffers, they should use the i2c_get_dma_safe_msg_buf() * and i2c_put_dma_safe_msg_buf() helpers provided by the I2C * framework. * This method is mandatory. * @request_ibi: attach an IBI handler to an I3C device. This implies defining * an IBI handler and the constraints of the IBI (maximum payload * length and number of pre-allocated slots). * Some controllers support less IBI-capable devices than regular * devices, so this method might return -%EBUSY if there's no * more space for an extra IBI registration * This method is optional. * @free_ibi: free an IBI previously requested with ->request_ibi(). The IBI * should have been disabled with ->disable_irq() prior to that * This method is mandatory only if ->request_ibi is not NULL. * @enable_ibi: enable the IBI. Only valid if ->request_ibi() has been called * prior to ->enable_ibi(). The controller should first enable * the IBI on the controller end (for example, unmask the hardware * IRQ) and then send the ENEC CCC command (with the IBI flag set) * to the I3C device. * This method is mandatory only if ->request_ibi is not NULL. * @disable_ibi: disable an IBI. First send the DISEC CCC command with the IBI * flag set and then deactivate the hardware IRQ on the * controller end. * This method is mandatory only if ->request_ibi is not NULL. * @recycle_ibi_slot: recycle an IBI slot. Called every time an IBI has been * processed by its handler. The IBI slot should be put back * in the IBI slot pool so that the controller can re-use it * for a future IBI * This method is mandatory only if ->request_ibi is not * NULL. */ struct i3c_master_controller_ops { int (*bus_init)(struct i3c_master_controller *master); void (*bus_cleanup)(struct i3c_master_controller *master); int (*attach_i3c_dev)(struct i3c_dev_desc *dev); int (*reattach_i3c_dev)(struct i3c_dev_desc *dev, u8 old_dyn_addr); void (*detach_i3c_dev)(struct i3c_dev_desc *dev); int (*do_daa)(struct i3c_master_controller *master); bool (*supports_ccc_cmd)(struct i3c_master_controller *master, const struct i3c_ccc_cmd *cmd); int (*send_ccc_cmd)(struct i3c_master_controller *master, struct i3c_ccc_cmd *cmd); int (*priv_xfers)(struct i3c_dev_desc *dev, struct i3c_priv_xfer *xfers, int nxfers); int (*attach_i2c_dev)(struct i2c_dev_desc *dev); void (*detach_i2c_dev)(struct i2c_dev_desc *dev); int (*i2c_xfers)(struct i2c_dev_desc *dev, const struct i2c_msg *xfers, int nxfers); int (*request_ibi)(struct i3c_dev_desc *dev, const struct i3c_ibi_setup *req); void (*free_ibi)(struct i3c_dev_desc *dev); int (*enable_ibi)(struct i3c_dev_desc *dev); int (*disable_ibi)(struct i3c_dev_desc *dev); void (*recycle_ibi_slot)(struct i3c_dev_desc *dev, struct i3c_ibi_slot *slot); }; /** * struct i3c_master_controller - I3C master controller object * @dev: device to be registered to the device-model * @this: an I3C device object representing this master. This device will be * added to the list of I3C devs available on the bus * @i2c: I2C adapter used for backward compatibility. This adapter is * registered to the I2C subsystem to be as transparent as possible to * existing I2C drivers * @ops: master operations. See &struct i3c_master_controller_ops * @secondary: true if the master is a secondary master * @init_done: true when the bus initialization is done * @boardinfo.i3c: list of I3C boardinfo objects * @boardinfo.i2c: list of I2C boardinfo objects * @boardinfo: board-level information attached to devices connected on the bus * @bus: I3C bus exposed by this master * @wq: workqueue used to execute IBI handlers. Can also be used by master * drivers if they need to postpone operations that need to take place * in a thread context. Typical examples are Hot Join processing which * requires taking the bus lock in maintenance, which in turn, can only * be done from a sleep-able context * * A &struct i3c_master_controller has to be registered to the I3C subsystem * through i3c_master_register(). None of &struct i3c_master_controller fields * should be set manually, just pass appropriate values to * i3c_master_register(). */ struct i3c_master_controller { struct device dev; struct i3c_dev_desc *this; struct i2c_adapter i2c; const struct i3c_master_controller_ops *ops; unsigned int secondary : 1; unsigned int init_done : 1; struct { struct list_head i3c; struct list_head i2c; } boardinfo; struct i3c_bus bus; struct workqueue_struct *wq; }; /** * i3c_bus_for_each_i2cdev() - iterate over all I2C devices present on the bus * @bus: the I3C bus * @dev: an I2C device descriptor pointer updated to point to the current slot * at each iteration of the loop * * Iterate over all I2C devs present on the bus. */ #define i3c_bus_for_each_i2cdev(bus, dev) \ list_for_each_entry(dev, &(bus)->devs.i2c, common.node) /** * i3c_bus_for_each_i3cdev() - iterate over all I3C devices present on the bus * @bus: the I3C bus * @dev: and I3C device descriptor pointer updated to point to the current slot * at each iteration of the loop * * Iterate over all I3C devs present on the bus. */ #define i3c_bus_for_each_i3cdev(bus, dev) \ list_for_each_entry(dev, &(bus)->devs.i3c, common.node) int i3c_master_do_i2c_xfers(struct i3c_master_controller *master, const struct i2c_msg *xfers, int nxfers); int i3c_master_disec_locked(struct i3c_master_controller *master, u8 addr, u8 evts); int i3c_master_enec_locked(struct i3c_master_controller *master, u8 addr, u8 evts); int i3c_master_entdaa_locked(struct i3c_master_controller *master); int i3c_master_defslvs_locked(struct i3c_master_controller *master); int i3c_master_get_free_addr(struct i3c_master_controller *master, u8 start_addr); int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master, u8 addr); int i3c_master_do_daa(struct i3c_master_controller *master); int i3c_master_set_info(struct i3c_master_controller *master, const struct i3c_device_info *info); int i3c_master_register(struct i3c_master_controller *master, struct device *parent, const struct i3c_master_controller_ops *ops, bool secondary); void i3c_master_unregister(struct i3c_master_controller *master); /** * i3c_dev_get_master_data() - get master private data attached to an I3C * device descriptor * @dev: the I3C device descriptor to get private data from * * Return: the private data previously attached with i3c_dev_set_master_data() * or NULL if no data has been attached to the device. */ static inline void *i3c_dev_get_master_data(const struct i3c_dev_desc *dev) { return dev->common.master_priv; } /** * i3c_dev_set_master_data() - attach master private data to an I3C device * descriptor * @dev: the I3C device descriptor to attach private data to * @data: private data * * This functions allows a master controller to attach per-device private data * which can then be retrieved with i3c_dev_get_master_data(). */ static inline void i3c_dev_set_master_data(struct i3c_dev_desc *dev, void *data) { dev->common.master_priv = data; } /** * i2c_dev_get_master_data() - get master private data attached to an I2C * device descriptor * @dev: the I2C device descriptor to get private data from * * Return: the private data previously attached with i2c_dev_set_master_data() * or NULL if no data has been attached to the device. */ static inline void *i2c_dev_get_master_data(const struct i2c_dev_desc *dev) { return dev->common.master_priv; } /** * i2c_dev_set_master_data() - attach master private data to an I2C device * descriptor * @dev: the I2C device descriptor to attach private data to * @data: private data * * This functions allows a master controller to attach per-device private data * which can then be retrieved with i2c_device_get_master_data(). */ static inline void i2c_dev_set_master_data(struct i2c_dev_desc *dev, void *data) { dev->common.master_priv = data; } /** * i3c_dev_get_master() - get master used to communicate with a device * @dev: I3C dev * * Return: the master controller driving @dev */ static inline struct i3c_master_controller * i3c_dev_get_master(struct i3c_dev_desc *dev) { return dev->common.master; } /** * i2c_dev_get_master() - get master used to communicate with a device * @dev: I2C dev * * Return: the master controller driving @dev */ static inline struct i3c_master_controller * i2c_dev_get_master(struct i2c_dev_desc *dev) { return dev->common.master; } /** * i3c_master_get_bus() - get the bus attached to a master * @master: master object * * Return: the I3C bus @master is connected to */ static inline struct i3c_bus * i3c_master_get_bus(struct i3c_master_controller *master) { return &master->bus; } struct i3c_generic_ibi_pool; struct i3c_generic_ibi_pool * i3c_generic_ibi_alloc_pool(struct i3c_dev_desc *dev, const struct i3c_ibi_setup *req); void i3c_generic_ibi_free_pool(struct i3c_generic_ibi_pool *pool); struct i3c_ibi_slot * i3c_generic_ibi_get_free_slot(struct i3c_generic_ibi_pool *pool); void i3c_generic_ibi_recycle_slot(struct i3c_generic_ibi_pool *pool, struct i3c_ibi_slot *slot); void i3c_master_queue_ibi(struct i3c_dev_desc *dev, struct i3c_ibi_slot *slot); struct i3c_ibi_slot *i3c_master_get_free_ibi_slot(struct i3c_dev_desc *dev); #endif /* I3C_MASTER_H */