/* 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 i3c_master_controller;
struct i3c_bus;
struct i2c_device;
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(9, 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
*
* 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;
const struct i2c_dev_boardinfo *boardinfo;
struct i2c_client *dev;
};
/**
* 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_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_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.
* @i2c_funcs: expose the supported I2C functionalities.
* 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);
u32 (*i2c_funcs)(struct i3c_master_controller *master);
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);
int 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 */
