/*
* SPDX-FileCopyrightText: 2010-2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
// Internal header, don't use it in the user code
#pragma once
#include <esp_intr_alloc.h>
#include "driver/spi_common.h"
#include "freertos/FreeRTOS.h"
#include "hal/spi_types.h"
#include "esp_pm.h"
#if SOC_GDMA_SUPPORTED
#include "esp_private/gdma.h"
#endif
#ifdef __cplusplus
extern "C"
{
#endif
#ifdef CONFIG_SPI_MASTER_ISR_IN_IRAM
#define SPI_MASTER_ISR_ATTR IRAM_ATTR
#else
#define SPI_MASTER_ISR_ATTR
#endif
#ifdef CONFIG_SPI_MASTER_IN_IRAM
#define SPI_MASTER_ATTR IRAM_ATTR
#else
#define SPI_MASTER_ATTR
#endif
#define BUS_LOCK_DEBUG 0
#if BUS_LOCK_DEBUG
#define BUS_LOCK_DEBUG_EXECUTE_CHECK(x) assert(x)
#else
#define BUS_LOCK_DEBUG_EXECUTE_CHECK(x)
#endif
struct spi_bus_lock_t;
struct spi_bus_lock_dev_t;
/// Handle to the lock of an SPI bus
typedef struct spi_bus_lock_t* spi_bus_lock_handle_t;
/// Handle to lock of one of the device on an SPI bus
typedef struct spi_bus_lock_dev_t* spi_bus_lock_dev_handle_t;
/// Background operation control function
typedef void (*bg_ctrl_func_t)(void*);
typedef struct lldesc_s lldesc_t;
/// Attributes of an SPI bus
typedef struct {
spi_bus_config_t bus_cfg; ///< Config used to initialize the bus
uint32_t flags; ///< Flags (attributes) of the bus
int max_transfer_sz; ///< Maximum length of bytes available to send
bool dma_enabled; ///< To enable DMA or not
int tx_dma_chan; ///< TX DMA channel, on ESP32 and ESP32S2, tx_dma_chan and rx_dma_chan are same
int rx_dma_chan; ///< RX DMA channel, on ESP32 and ESP32S2, tx_dma_chan and rx_dma_chan are same
int dma_desc_num; ///< DMA descriptor number of dmadesc_tx or dmadesc_rx.
lldesc_t *dmadesc_tx; ///< DMA descriptor array for TX
lldesc_t *dmadesc_rx; ///< DMA descriptor array for RX
spi_bus_lock_handle_t lock;
#ifdef CONFIG_PM_ENABLE
esp_pm_lock_handle_t pm_lock; ///< Power management lock
#endif
} spi_bus_attr_t;
/// Destructor called when a bus is deinitialized.
typedef esp_err_t (*spi_destroy_func_t)(void*);
/**
* @brief Try to claim a SPI peripheral
*
* Call this if your driver wants to manage a SPI peripheral.
*
* @param host Peripheral to claim
* @param source The caller indentification string.
*
* @return True if peripheral is claimed successfully; false if peripheral already is claimed.
*/
bool spicommon_periph_claim(spi_host_device_t host, const char* source);
/**
* @brief Check whether the spi periph is in use.
*
* @param host Peripheral to check.
*
* @return True if in use, otherwise false.
*/
bool spicommon_periph_in_use(spi_host_device_t host);
/**
* @brief Return the SPI peripheral so another driver can claim it.
*
* @param host Peripheral to return
*
* @return True if peripheral is returned successfully; false if peripheral was free to claim already.
*/
bool spicommon_periph_free(spi_host_device_t host);
/**
* @brief Alloc DMA for SPI
*
* @param host_id SPI host ID
* @param dma_chan DMA channel to be used
* @param[out] out_actual_tx_dma_chan Actual TX DMA channel (if you choose to assign a specific DMA channel, this will be the channel you assigned before)
* @param[out] out_actual_rx_dma_chan Actual RX DMA channel (if you choose to assign a specific DMA channel, this will be the channel you assigned before)
*
* @return
* - ESP_OK: On success
* - ESP_ERR_NO_MEM: No enough memory
* - ESP_ERR_NOT_FOUND: There is no available DMA channel
*/
esp_err_t spicommon_dma_chan_alloc(spi_host_device_t host_id, spi_dma_chan_t dma_chan, uint32_t *out_actual_tx_dma_chan, uint32_t *out_actual_rx_dma_chan);
/**
* @brief Free DMA for SPI
*
* @param host_id SPI host ID
*
* @return
* - ESP_OK: On success
*/
esp_err_t spicommon_dma_chan_free(spi_host_device_t host_id);
#if SOC_GDMA_SUPPORTED
/**
* @brief Get SPI GDMA Handle for GMDA Supported Chip
*
* @param host_id SPI host ID
* @param gdma_handle GDMA Handle to Return
* @param gdma_direction GDMA Channel Direction in Enum
* - GDMA_CHANNEL_DIRECTION_TX
* - GDMA_CHANNEL_DIRECTION_RX
*
* @return
* - ESP_OK: On success
*/
esp_err_t spicommon_gdma_get_handle(spi_host_device_t host_id, gdma_channel_handle_t *gdma_handle, gdma_channel_direction_t gdma_direction);
#endif
/**
* @brief Connect a SPI peripheral to GPIO pins
*
* This routine is used to connect a SPI peripheral to the IO-pads and DMA channel given in
* the arguments. Depending on the IO-pads requested, the routing is done either using the
* IO_mux or using the GPIO matrix.
*
* @param host SPI peripheral to be routed
* @param bus_config Pointer to a spi_bus_config struct detailing the GPIO pins
* @param flags Combination of SPICOMMON_BUSFLAG_* flags, set to ensure the pins set are capable with some functions:
* - ``SPICOMMON_BUSFLAG_MASTER``: Initialize I/O in master mode
* - ``SPICOMMON_BUSFLAG_SLAVE``: Initialize I/O in slave mode
* - ``SPICOMMON_BUSFLAG_IOMUX_PINS``: Pins set should match the iomux pins of the controller.
* - ``SPICOMMON_BUSFLAG_SCLK``, ``SPICOMMON_BUSFLAG_MISO``, ``SPICOMMON_BUSFLAG_MOSI``:
* Make sure SCLK/MISO/MOSI is/are set to a valid GPIO. Also check output capability according to the mode.
* - ``SPICOMMON_BUSFLAG_DUAL``: Make sure both MISO and MOSI are output capable so that DIO mode is capable.
* - ``SPICOMMON_BUSFLAG_WPHD`` Make sure WP and HD are set to valid output GPIOs.
* - ``SPICOMMON_BUSFLAG_QUAD``: Combination of ``SPICOMMON_BUSFLAG_DUAL`` and ``SPICOMMON_BUSFLAG_WPHD``.
* - ``SPICOMMON_BUSFLAG_IO4_IO7``: Make sure spi data4 ~ spi data7 are set to valid output GPIOs.
* - ``SPICOMMON_BUSFLAG_OCTAL``: Combination of ``SPICOMMON_BUSFLAG_QUAL`` and ``SPICOMMON_BUSFLAG_IO4_IO7``.
* @param[out] flags_o A SPICOMMON_BUSFLAG_* flag combination of bus abilities will be written to this address.
* Leave to NULL if not needed.
* - ``SPICOMMON_BUSFLAG_IOMUX_PINS``: The bus is connected to iomux pins.
* - ``SPICOMMON_BUSFLAG_SCLK``, ``SPICOMMON_BUSFLAG_MISO``, ``SPICOMMON_BUSFLAG_MOSI``: The bus has
* CLK/MISO/MOSI connected.
* - ``SPICOMMON_BUSFLAG_DUAL``: The bus is capable with DIO mode.
* - ``SPICOMMON_BUSFLAG_WPHD`` The bus has WP and HD connected.
* - ``SPICOMMON_BUSFLAG_QUAD``: Combination of ``SPICOMMON_BUSFLAG_DUAL`` and ``SPICOMMON_BUSFLAG_WPHD``.
* - ``SPICOMMON_BUSFLAG_IO4_IO7``: The bus has spi data4 ~ spi data7 connected.
* - ``SPICOMMON_BUSFLAG_OCTAL``: Combination of ``SPICOMMON_BUSFLAG_QUAL`` and ``SPICOMMON_BUSFLAG_IO4_IO7``.
* @return
* - ESP_ERR_INVALID_ARG if parameter is invalid
* - ESP_OK on success
*/
esp_err_t spicommon_bus_initialize_io(spi_host_device_t host, const spi_bus_config_t *bus_config, uint32_t flags, uint32_t *flags_o);
/**
* @brief Free the IO used by a SPI peripheral
*
* @param bus_cfg Bus config struct which defines which pins to be used.
*
* @return
* - ESP_ERR_INVALID_ARG if parameter is invalid
* - ESP_OK on success
*/
esp_err_t spicommon_bus_free_io_cfg(const spi_bus_config_t *bus_cfg);
/**
* @brief Initialize a Chip Select pin for a specific SPI peripheral
*
* @param host SPI peripheral
* @param cs_io_num GPIO pin to route
* @param cs_num CS id to route
* @param force_gpio_matrix If true, CS will always be routed through the GPIO matrix. If false,
* if the GPIO number allows it, the routing will happen through the IO_mux.
*/
void spicommon_cs_initialize(spi_host_device_t host, int cs_io_num, int cs_num, int force_gpio_matrix);
/**
* @brief Free a chip select line
*
* @param cs_gpio_num CS gpio num to free
*/
void spicommon_cs_free_io(int cs_gpio_num);
/**
* @brief Check whether all pins used by a host are through IOMUX.
*
* @param host SPI peripheral
*
* @return false if any pins are through the GPIO matrix, otherwise true.
*/
bool spicommon_bus_using_iomux(spi_host_device_t host);
/**
* @brief Get the IRQ source for a specific SPI host
*
* @param host The SPI host
*
* @return The hosts IRQ source
*/
int spicommon_irqsource_for_host(spi_host_device_t host);
/**
* @brief Get the IRQ source for a specific SPI DMA
*
* @param host The SPI host
*
* @return The hosts IRQ source
*/
int spicommon_irqdma_source_for_host(spi_host_device_t host);
/**
* Callback, to be called when a DMA engine reset is completed
*/
typedef void(*dmaworkaround_cb_t)(void *arg);
#if CONFIG_IDF_TARGET_ESP32
//This workaround is only for esp32
/**
* @brief Request a reset for a certain DMA channel
*
* @note In some (well-defined) cases in the ESP32 (at least rev v.0 and v.1), a SPI DMA channel will get confused. This can be remedied
* by resetting the SPI DMA hardware in case this happens. Unfortunately, the reset knob used for thsi will reset _both_ DMA channels, and
* as such can only done safely when both DMA channels are idle. These functions coordinate this.
*
* Essentially, when a reset is needed, a driver can request this using spicommon_dmaworkaround_req_reset. This is supposed to be called
* with an user-supplied function as an argument. If both DMA channels are idle, this call will reset the DMA subsystem and return true.
* If the other DMA channel is still busy, it will return false; as soon as the other DMA channel is done, however, it will reset the
* DMA subsystem and call the callback. The callback is then supposed to be used to continue the SPI drivers activity.
*
* @param dmachan DMA channel associated with the SPI host that needs a reset
* @param cb Callback to call in case DMA channel cannot be reset immediately
* @param arg Argument to the callback
*
* @return True when a DMA reset could be executed immediately. False when it could not; in this
* case the callback will be called with the specified argument when the logic can execute
* a reset, after that reset.
*/
bool spicommon_dmaworkaround_req_reset(int dmachan, dmaworkaround_cb_t cb, void *arg);
/**
* @brief Check if a DMA reset is requested but has not completed yet
*
* @return True when a DMA reset is requested but hasn't completed yet. False otherwise.
*/
bool spicommon_dmaworkaround_reset_in_progress(void);
/**
* @brief Mark a DMA channel as idle.
*
* A call to this function tells the workaround logic that this channel will
* not be affected by a global SPI DMA reset.
*/
void spicommon_dmaworkaround_idle(int dmachan);
/**
* @brief Mark a DMA channel as active.
*
* A call to this function tells the workaround logic that this channel will
* be affected by a global SPI DMA reset, and a reset like that should not be attempted.
*/
void spicommon_dmaworkaround_transfer_active(int dmachan);
#endif //#if CONFIG_IDF_TARGET_ESP32
/*******************************************************************************
* Bus attributes
******************************************************************************/
/**
* @brief Set bus lock for the main bus, called by startup code.
*
* @param lock The lock to be used by the main SPI bus.
*/
void spi_bus_main_set_lock(spi_bus_lock_handle_t lock);
/**
* @brief Get the attributes of a specified SPI bus.
*
* @param host_id The specified host to get attribute
* @return (Const) Pointer to the attributes
*/
const spi_bus_attr_t* spi_bus_get_attr(spi_host_device_t host_id);
/**
* @brief Register a function to a initialized bus to make it called when deinitializing the bus.
*
* @param host_id The SPI bus to register the destructor.
* @param f Destructor to register
* @param arg The argument to call the destructor
* @return Always ESP_OK.
*/
esp_err_t spi_bus_register_destroy_func(spi_host_device_t host_id,
spi_destroy_func_t f, void *arg);
/*******************************************************************************
* SPI Bus Lock for arbitration among SPI master (intr, polling) trans, SPI flash operations and
* flash/psram cache access.
*
* NON-PUBLIC API. Don't use it directly in applications.
*
* There is the main lock corresponding to an SPI bus, of which several devices (holding child
* locks) attaching to it. Each of the device is STRONGLY RECOMMENDED to be used in only one task
* to avoid concurrency issues.
*
* Terms:
* - BG operations (BackGround operations) means some transaction that will not immediately /
* explicitly be sent in the task. It can be some cache access, or interrupt transactions.
*
* - Operation: usage of the bus, for example, do SPI transactions.
*
* - Acquiring processor: the task or the ISR that is allowed to use the bus. No operations will be
* performed if there is no acquiring processor. A processor becomes the acquiring processor if
* it ask for that when no acquiring processor exist, otherwise it has to wait for the acquiring
* processor to handle over the role to it. The acquiring processor will and will only assign one
* acquiring processor in the waiting list (if not empty) when it finishes its operation.
*
* - Acquiring device: the only device allowed to use the bus. Operations can be performed in
* either the BG or the task. When there's no acquiring device, only the ISR is allowed to be the
* acquiring processor and perform operations on the bus.
*
* When a device wants to perform operations, it either:
* 1. Acquire the bus, and operate in the task (e.g. polling transactions of SPI master, and SPI flash
* operations)
*
* 2. Request a BG operation. And the ISR will be enabled at proper time.
*
* For example if a task wants to send an interrupt transaction, it prepares the data in the task,
* call `spi_bus_lock_bg_request`, and handle sending in the ISR.
*
* 3. When a device has already acquired the bus, BG operations are also allowed. After the
* `spi_bus_lock_bg_request` is called, call `spi_bus_lock_wait_bg_done` before operations in task
* again to wait until BG operations are done.
*
* Any device may try to invoke the ISR (by `spi_bus_lock_bg_request`). The ISR will be invoked and
* become the acquiring processor immediately when the bus is not acquired by other processors. Any
* device may also try to acquire the bus (by `spi_bus_lock_acquire_start`). The device will become
* the acquiring processor immediately when the bus is not acquired and there is no request active.
*
* The acquiring processor must be aware of its acquiring role, and properly transfer the acquiring
* processor to other tasks or ISR when they have nothing else to do. Before picking a new
* acquiring processor, a new acquiring device must be picked first, if there are other devices,
* asking to be acquiring device. After that, the new acquiring processor is picked by the sequence
* below:
*
* 1. If there is an acquiring device:
* 1.1 The ISR, if acquiring device has active BG requests
* 1.2 The task of the device, if no active BG request for the device
* 2. The ISR, if there's no acquiring device, but any BG request is active
* 3. No one becomes the acquiring processor
*
* The API also helps on the arbitration of SPI cs lines. The bus is initialized with a cs_num
* argument. When attaching devices onto the bus with `spi_bus_lock_register_dev`, it will allocate
* devices with different device ID according to the flags given. If the ID is smaller than the
* cs_num given when bus is initialized, error will be returned.
*
* Usage:
* * Initialization:
* 1. Call `spi_bus_init_lock` to register a lock for a bus.
* 2. Call `spi_bus_lock_set_bg_control` to prepare BG enable/disable functions for
* the lock.
* 3. Call `spi_bus_lock_register_dev` for each devices that may make use of the
* bus, properly store the returned handle, representing those devices.
*
* * Acquiring:
* 1. Call `spi_bus_lock_acquire_start` when a device wants to use the bus
* 2. Call `spi_bus_lock_touch` to mark the bus as touched by this device. Also check if the bus
* has been touched by other devices.
* 3. (optional) Do something on the bus...
* 4. (optional) Call `spi_bus_lock_bg_request` to inform and invoke the BG. See ISR below about
* ISR operations.
* 5. (optional) If `spi_bus_lock_bg_request` is done, you have to call `spi_bus_lock_wait_bg_done`
* before touching the bus again, or do the following steps.
* 6. Call `spi_bus_lock_acquire_end` to release the bus to other devices.
*
* * ISR:
* 1. Call `spi_bus_lock_bg_entry` when entering the ISR, run or skip the closure for the previous
* operation according to the return value.
* 2. Call `spi_bus_lock_get_acquiring_dev` to get the acquiring device. If there is no acquiring
* device, call `spi_bus_lock_bg_check_dev_acq` to check and update a new acquiring device.
* 3. Call `spi_bus_lock_bg_check_dev_req` to check for request of the desired device. If the
* desired device is not requested, go to step 5.
* 4. Check, start operation for the desired device and go to step 6; otherwise if no operations
* can be performed, call `spi_bus_lock_bg_clear_req` to clear the request for this device. If
* `spi_bus_lock_bg_clear_req` is called and there is no BG requests active, goto step 6.
* 5. (optional) If the device is the acquiring device, go to step 6, otherwise
* find another desired device, and go back to step 3.
* 6. Call `spi_bus_lock_bg_exit` to try quitting the ISR. If failed, go back to step 2 to look for
* a new request again. Otherwise, quit the ISR.
*
* * Deinitialization (optional):
* 1. Call `spi_bus_lock_unregister_dev` for each device when they are no longer needed.
* 2. Call `spi_bus_deinit_lock` to release the resources occupied by the lock.
*
* Some technical details:
*
* The child-lock of each device will have its own Binary Semaphore, which allows the task serving
* this device (task A) being blocked when it fail to become the acquiring processor while it's
* calling `spi_bus_lock_acquire_start` or `spi_bus_lock_wait_bg_done`. If it is blocked, there
* must be an acquiring processor (either the ISR or another task (task B)), is doing transaction
* on the bus. After that, task A will get unblocked and become the acquiring processor when the
* ISR call `spi_bus_lock_bg_resume_acquired_dev`, or task B call `spi_bus_lock_acquire_end`.
*
* When the device wants to send ISR transaction, it should call `spi_bus_lock_bg_request` after
* the data is prepared. This function sets a request bit in the critical resource. The ISR will be
* invoked and become the new acquiring processor, when:
*
* 1. A task calls `spi_bus_lock_bg_request` while there is no acquiring processor;
* 2. A tasks calls `spi_bus_lock_bg_request` while the task is the acquiring processor. Then the
* acquiring processor is handled over to the ISR;
* 3. A tasks who is the acquiring processor release the bus by calling `spi_bus_lock_acquire_end`,
* and the ISR happens to be the next acquiring processor.
*
* The ISR will check (by `spi_bus_lock_bg_check_dev_req`) and clear a request bit (by
* `spi_bus_lock_bg_clear_req`) after it confirm that all the requests of the corresponding device
* are served. The request bit supports being written to recursively, which means, the task don't
* need to wait for `spi_bus_lock_bg_clear_req` before call another `spi_bus_lock_bg_request`. The
* API will handle the concurrency conflicts properly.
*
* The `spi_bus_lock_bg_exit` (together with `spi_bus_lock_bg_entry` called before)` is responsible
* to ensure ONE and ONLY ONE of the following will happen when the ISR try to give up its
* acquiring processor rule:
*
* 1. ISR quit, no any task unblocked while the interrupt disabled, and none of the BG bits is
* active.
* 2. ISR quit, there is an acquiring device, and the acquiring processor is passed to the task
* serving the acquiring device by unblocking the task.
* 3. The ISR failed to quit and have to try again.
******************************************************************************/
#define DEV_NUM_MAX 6 ///< Number of devices supported by this lock
/// Lock configuration struct
typedef struct {
int host_id; ///< SPI host id
int cs_num; ///< Physical cs numbers of the host
} spi_bus_lock_config_t;
/// Child-lock configuration struct
typedef struct {
uint32_t flags; ///< flags for the lock, OR-ed of `SPI_BUS_LOCK_DEV_*` flags.
#define SPI_BUS_LOCK_DEV_FLAG_CS_REQUIRED BIT(0) ///< The device needs a physical CS pin.
} spi_bus_lock_dev_config_t;
/************* Common *********************/
/**
* Initialize a lock for an SPI bus.
*
* @param out_lock Output of the handle to the lock
* @return
* - ESP_ERR_NO_MEM: if memory exhausted
* - ESP_OK: if success
*/
esp_err_t spi_bus_init_lock(spi_bus_lock_handle_t *out_lock, const spi_bus_lock_config_t *config);
/**
* Free the resources used by an SPI bus lock.
*
* @note All attached devices should have been unregistered before calling this
* funciton.
*
* @param lock Handle to the lock to free.
*/
void spi_bus_deinit_lock(spi_bus_lock_handle_t lock);
/**
* @brief Get the corresponding lock according to bus id.
*
* @param host_id The bus id to get the lock
* @return The lock handle
*/
spi_bus_lock_handle_t spi_bus_lock_get_by_id(spi_host_device_t host_id);
/**
* @brief Configure how the SPI bus lock enable the background operation.
*
* @note The lock will not try to stop the background operations, but wait for
* The background operations finished indicated by `spi_bus_lock_bg_resume_acquired_dev`.
*
* @param lock Handle to the lock to set
* @param bg_enable The enabling function
* @param bg_disable The disabling function, set to NULL if not required
* @param arg Argument to pass to the enabling/disabling function.
*/
void spi_bus_lock_set_bg_control(spi_bus_lock_handle_t lock, bg_ctrl_func_t bg_enable,
bg_ctrl_func_t bg_disable, void *arg);
/**
* Attach a device onto an SPI bus lock. The returning handle is used to perform
* following requests for the attached device.
*
* @param lock SPI bus lock to attach
* @param out_dev_handle Output handle corresponding to the device
* @param flags requirement of the device, bitwise OR of SPI_BUS_LOCK_FLAG_* flags
*
* @return
* - ESP_ERR_NOT_SUPPORTED: if there's no hardware resources for new devices.
* - ESP_ERR_NO_MEM: if memory exhausted
* - ESP_OK: if success
*/
esp_err_t spi_bus_lock_register_dev(spi_bus_lock_handle_t lock,
spi_bus_lock_dev_config_t *config,
spi_bus_lock_dev_handle_t *out_dev_handle);
/**
* Detach a device from its bus and free the resources used
*
* @param dev_handle Handle to the device.
*/
void spi_bus_lock_unregister_dev(spi_bus_lock_dev_handle_t dev_handle);
/**
* @brief Get the parent bus lock of the device
*
* @param dev_handle Handle to the device to get bus lock
* @return The bus lock handle
*/
spi_bus_lock_handle_t spi_bus_lock_get_parent(spi_bus_lock_dev_handle_t dev_handle);
/**
* @brief Get the device ID of a lock.
*
* The callers should allocate CS pins according to this ID.
*
* @param dev_handle Handle to the device to get ID
* @return ID of the device
*/
int spi_bus_lock_get_dev_id(spi_bus_lock_dev_handle_t dev_handle);
/**
* @brief The device request to touch bus registers. Can only be called by the acquiring processor.
*
* Also check if the registers has been touched by other devices.
*
* @param dev_handle Handle to the device to operate the registers
* @return true if there has been other devices touching SPI registers.
* The caller may need to do a full-configuration. Otherwise return
* false.
*/
bool spi_bus_lock_touch(spi_bus_lock_dev_handle_t dev_handle);
/************* Acquiring service *********************/
/**
* Acquiring the SPI bus for exclusive use. Will also wait for the BG to finish all requests of
* this device before it returns.
*
* After successfully return, the caller becomes the acquiring processor.
*
* @note For the main flash bus, `bg_disable` will be called to disable the cache.
*
* @param dev_handle Handle to the device request for acquiring.
* @param wait Time to wait until timeout or succeed, must be `portMAX_DELAY` for now.
* @return
* - ESP_OK: on success
* - ESP_ERR_INVALID_ARG: timeout is not portMAX_DELAY
*/
esp_err_t spi_bus_lock_acquire_start(spi_bus_lock_dev_handle_t dev_handle, TickType_t wait);
/**
* Release the bus acquired. Will pass the acquiring processor to other blocked
* processors (tasks or ISR), and cause them to be unblocked or invoked.
*
* The acquiring device may also become NULL if no device is asking for acquiring.
* In this case, the BG may be invoked if there is any BG requests.
*
* If the new acquiring device has BG requests, the BG will be invoked before the
* task is resumed later after the BG finishes all requests of the new acquiring
* device. Otherwise the task of the new acquiring device will be resumed immediately.
*
* @param dev_handle Handle to the device releasing the bus.
* @return
* - ESP_OK: on success
* - ESP_ERR_INVALID_STATE: the device hasn't acquired the lock yet
*/
esp_err_t spi_bus_lock_acquire_end(spi_bus_lock_dev_handle_t dev_handle);
/**
* Get the device acquiring the bus.
*
* @note Return value is not stable as the acquiring processor may change
* when this function is called.
*
* @param lock Lock of SPI bus to get the acquiring device.
* @return The argument corresponding to the acquiring device, see
* `spi_bus_lock_register_dev`.
*/
spi_bus_lock_dev_handle_t spi_bus_lock_get_acquiring_dev(spi_bus_lock_handle_t lock);
/************* BG (Background, for ISR or cache) service *********************/
/**
* Call by a device to request a BG operation.
*
* Depending on the bus lock state, the BG operations may be resumed by this
* call, or pending until BG operations allowed.
*
* Cleared by `spi_bus_lock_bg_clear_req` in the BG.
*
* @param dev_handle The device requesting BG operations.
* @return always ESP_OK
*/
esp_err_t spi_bus_lock_bg_request(spi_bus_lock_dev_handle_t dev_handle);
/**
* Wait until the ISR has finished all the BG operations for the acquiring device.
* If any `spi_bus_lock_bg_request` for this device has been called after
* `spi_bus_lock_acquire_start`, this function must be called before any operation
* in the task.
*
* @note Can only be called when bus acquired by this device.
*
* @param dev_handle Handle to the device acquiring the bus.
* @param wait Time to wait until timeout or succeed, must be `portMAX_DELAY` for now.
* @return
* - ESP_OK: on success
* - ESP_ERR_INVALID_STATE: The device is not the acquiring bus.
* - ESP_ERR_INVALID_ARG: Timeout is not portMAX_DELAY.
*/
esp_err_t spi_bus_lock_wait_bg_done(spi_bus_lock_dev_handle_t dev_handle, TickType_t wait);
/**
* Handle interrupt and closure of last operation. Should be called at the beginning of the ISR,
* when the ISR is acting as the acquiring processor.
*
* @param lock The SPI bus lock
*
* @return false if the ISR has already touched the HW, should run closure of the
* last operation first; otherwise true if the ISR just start operating
* on the HW, closure should be skipped.
*/
bool spi_bus_lock_bg_entry(spi_bus_lock_handle_t lock);
/**
* Handle the scheduling of other acquiring devices, and control of HW operation
* status.
*
* If no BG request is found, call with `wip=false`. This function will return false,
* indicating there is incoming BG requests for the current acquiring device (or
* for all devices if there is no acquiring device) and the ISR needs retry.
* Otherwise may schedule a new acquiring processor (unblock the task) if there
* is, and return true.
*
* Otherwise if a BG request is started in this ISR, call with `wip=true` and the
* function will enable the interrupt to make the ISR be called again when the
* request is done.
*
* This function is safe and should still be called when the ISR just lost its acquiring processor
* role, but hasn't quit.
*
* @note This function will not change acquiring device. The ISR call
* `spi_bus_lock_bg_update_acquiring` to check for new acquiring device,
* when acquiring devices need to be served before other devices.
*
* @param lock The SPI bus lock.
* @param wip Whether an operation is being executed when quitting the ISR.
* @param do_yield[out] Not touched when no yielding required, otherwise set
* to pdTRUE.
* @return false if retry is required, indicating that there is pending BG request.
* otherwise true and quit ISR is allowed.
*/
bool spi_bus_lock_bg_exit(spi_bus_lock_handle_t lock, bool wip, BaseType_t* do_yield);
/**
* Check whether there is device asking for the acquiring device, and the desired
* device for the next operation is also recommended.
*
* @note Must be called when the ISR is acting as the acquiring processor, and
* there is no acquiring device.
*
* @param lock The SPI bus lock.
* @param out_dev_lock The recommended device for hte next operation. It's the new
* acquiring device when found, otherwise a device that has active BG request.
*
* @return true if the ISR need to quit (new acquiring device has no active BG
* request, or no active BG requests for all devices when there is no
* acquiring device), otherwise false.
*/
bool spi_bus_lock_bg_check_dev_acq(spi_bus_lock_handle_t lock, spi_bus_lock_dev_handle_t *out_dev_lock);
/**
* Check if the device has BG requests. Must be called when the ISR is acting as
* the acquiring processor.
*
* @note This is not stable, may become true again when a task request for BG
* operation (by `spi_bus_lock_bg_request`).
*
* @param dev_lock The device to check.
* @return true if the device has BG requests, otherwise false.
*/
bool spi_bus_lock_bg_check_dev_req(spi_bus_lock_dev_handle_t dev_lock);
/**
* Clear the pending BG operation request of a device after served. Must be
* called when the ISR is acting as the acquiring processor.
*
* @note When the return value is true, the ISR will lost the acquiring processor role. Then
* `spi_bus_lock_bg_exit` must be called and checked before calling all other functions that
* require to be called when the ISR is the acquiring processor again.
*
* @param dev_handle The device whose request is served.
* @return True if no pending requests for the acquiring device, or for all devices
* if there is no acquiring device. Otherwise false. When the return value is
* true, the ISR is no longer the acquiring processor.
*/
bool spi_bus_lock_bg_clear_req(spi_bus_lock_dev_handle_t dev_lock);
/**
* Check if there is any active BG requests.
*
* @param lock The SPI bus lock.
* @return true if any device has active BG requst, otherwise false.
*/
bool spi_bus_lock_bg_req_exist(spi_bus_lock_handle_t lock);
/*******************************************************************************
* Variable and APIs for the OS to initialize the locks for the main chip
******************************************************************************/
/// The lock for the main bus
extern const spi_bus_lock_handle_t g_main_spi_bus_lock;
/**
* @brief Initialize the main SPI bus, called during chip startup.
*
* @return always ESP_OK
*/
esp_err_t spi_bus_lock_init_main_bus(void);
/// The lock for the main flash device
extern const spi_bus_lock_dev_handle_t g_spi_lock_main_flash_dev;
/**
* @brief Initialize the main flash device, called during chip startup.
*
* @return
* - ESP_OK: if success
* - ESP_ERR_NO_MEM: memory exhausted
*/
esp_err_t spi_bus_lock_init_main_dev(void);
#ifdef __cplusplus
}
#endif