251 lines
9.2 KiB
C
251 lines
9.2 KiB
C
// Copyright 2010-2017 Espressif Systems (Shanghai) PTE LTD
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#ifndef _DRIVER_SPI_COMMON_H_
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#define _DRIVER_SPI_COMMON_H_
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#include <stdint.h>
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#include <stdbool.h>
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#include "esp_err.h"
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#include "soc/spi_struct.h"
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#include "rom/lldesc.h"
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#ifdef __cplusplus
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extern "C"
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{
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#endif
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//Maximum amount of bytes that can be put in one DMA descriptor
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#define SPI_MAX_DMA_LEN (4096-4)
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/**
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* @brief Enum with the three SPI peripherals that are software-accessible in it
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*/
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typedef enum {
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SPI_HOST=0, ///< SPI1, SPI
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HSPI_HOST=1, ///< SPI2, HSPI
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VSPI_HOST=2 ///< SPI3, VSPI
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} spi_host_device_t;
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/**
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* @brief This is a configuration structure for a SPI bus.
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*
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* You can use this structure to specify the GPIO pins of the bus. Normally, the driver will use the
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* GPIO matrix to route the signals. An exception is made when all signals either can be routed through
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* the IO_MUX or are -1. In that case, the IO_MUX is used, allowing for >40MHz speeds.
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*
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* @note Be advised that the slave driver does not use the quadwp/quadhd lines and fields in spi_bus_config_t refering to these lines will be ignored and can thus safely be left uninitialized.
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*/
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typedef struct {
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int mosi_io_num; ///< GPIO pin for Master Out Slave In (=spi_d) signal, or -1 if not used.
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int miso_io_num; ///< GPIO pin for Master In Slave Out (=spi_q) signal, or -1 if not used.
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int sclk_io_num; ///< GPIO pin for Spi CLocK signal, or -1 if not used.
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int quadwp_io_num; ///< GPIO pin for WP (Write Protect) signal which is used as D2 in 4-bit communication modes, or -1 if not used.
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int quadhd_io_num; ///< GPIO pin for HD (HolD) signal which is used as D3 in 4-bit communication modes, or -1 if not used.
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int max_transfer_sz; ///< Maximum transfer size, in bytes. Defaults to 4094 if 0.
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} spi_bus_config_t;
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/**
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* @brief Try to claim a SPI peripheral
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*
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* Call this if your driver wants to manage a SPI peripheral.
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*
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* @param host Peripheral to claim
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* @return True if peripheral is claimed successfully; false if peripheral already is claimed.
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*/
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bool spicommon_periph_claim(spi_host_device_t host);
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/**
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* @brief Return the SPI peripheral so another driver can claim it.
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*
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* @param host Peripheral to return
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* @return True if peripheral is returned successfully; false if peripheral was free to claim already.
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*/
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bool spicommon_periph_free(spi_host_device_t host);
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/**
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* @brief Try to claim a SPI DMA channel
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*
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* Call this if your driver wants to use SPI with a DMA channnel.
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*
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* @param dma_chan channel to claim
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*
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* @return True if success; false otherwise.
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*/
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bool spicommon_dma_chan_claim(int dma_chan);
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/**
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* @brief Return the SPI DMA channel so other driver can claim it, or just to power down DMA.
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*
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* @param dma_chan channel to return
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*
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* @return True if success; false otherwise.
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*/
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bool spicommon_dma_chan_free(int dma_chan);
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#define SPICOMMON_BUSFLAG_SLAVE 0 ///< Initialize I/O in slave mode
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#define SPICOMMON_BUSFLAG_MASTER (1<<0) ///< Initialize I/O in master mode
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#define SPICOMMON_BUSFLAG_QUAD (1<<1) ///< Also initialize WP/HD pins, if specified
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/**
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* @brief Connect a SPI peripheral to GPIO pins
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*
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* This routine is used to connect a SPI peripheral to the IO-pads and DMA channel given in
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* the arguments. Depending on the IO-pads requested, the routing is done either using the
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* IO_mux or using the GPIO matrix.
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*
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* @param host SPI peripheral to be routed
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* @param bus_config Pointer to a spi_bus_config struct detailing the GPIO pins
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* @param dma_chan DMA-channel (1 or 2) to use, or 0 for no DMA.
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* @param flags Combination of SPICOMMON_BUSFLAG_* flags
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* @param[out] is_native A value of 'true' will be written to this address if the GPIOs can be
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* routed using the IO_mux, 'false' if the GPIO matrix is used.
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* @return
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* - ESP_ERR_INVALID_ARG if parameter is invalid
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* - ESP_OK on success
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*/
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esp_err_t spicommon_bus_initialize_io(spi_host_device_t host, const spi_bus_config_t *bus_config, int dma_chan, int flags, bool *is_native);
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/**
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* @brief Free the IO used by a SPI peripheral
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*
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* @param host SPI peripheral to be freed
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* @return
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* - ESP_ERR_INVALID_ARG if parameter is invalid
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* - ESP_OK on success
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*/
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esp_err_t spicommon_bus_free_io(spi_host_device_t host);
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/**
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* @brief Initialize a Chip Select pin for a specific SPI peripheral
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*
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*
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* @param host SPI peripheral
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* @param cs_io_num GPIO pin to route
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* @param cs_num CS id to route
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* @param force_gpio_matrix If true, CS will always be routed through the GPIO matrix. If false,
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* if the GPIO number allows it, the routing will happen through the IO_mux.
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*/
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void spicommon_cs_initialize(spi_host_device_t host, int cs_io_num, int cs_num, int force_gpio_matrix);
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/**
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* @brief Free a chip select line
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*
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* @param host SPI peripheral
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* @param cs_num CS id to free
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*/
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void spicommon_cs_free(spi_host_device_t host, int cs_num);
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/**
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* @brief Setup a DMA link chain
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*
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* This routine will set up a chain of linked DMA descriptors in the array pointed to by
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* ``dmadesc``. Enough DMA descriptors will be used to fit the buffer of ``len`` bytes in, and the
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* descriptors will point to the corresponding positions in ``buffer`` and linked together. The
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* end result is that feeding ``dmadesc[0]`` into DMA hardware results in the entirety ``len`` bytes
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* of ``data`` being read or written.
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*
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* @param dmadesc Pointer to array of DMA descriptors big enough to be able to convey ``len`` bytes
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* @param len Length of buffer
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* @param data Data buffer to use for DMA transfer
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* @param isrx True if data is to be written into ``data``, false if it's to be read from ``data``.
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*/
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void spicommon_setup_dma_desc_links(lldesc_t *dmadesc, int len, const uint8_t *data, bool isrx);
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/**
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* @brief Get the position of the hardware registers for a specific SPI host
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*
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* @param host The SPI host
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*
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* @return A register descriptor stuct pointer, pointed at the hardware registers
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*/
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spi_dev_t *spicommon_hw_for_host(spi_host_device_t host);
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/**
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* @brief Get the IRQ source for a specific SPI host
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*
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* @param host The SPI host
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*
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* @return The hosts IRQ source
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*/
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int spicommon_irqsource_for_host(spi_host_device_t host);
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/**
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* Callback, to be called when a DMA engine reset is completed
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*/
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typedef void(*dmaworkaround_cb_t)(void *arg);
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/**
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* @brief Request a reset for a certain DMA channel
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*
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* @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
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* by resetting the SPI DMA hardware in case this happens. Unfortunately, the reset knob used for thsi will reset _both_ DMA channels, and
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* as such can only done safely when both DMA channels are idle. These functions coordinate this.
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*
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* Essentially, when a reset is needed, a driver can request this using spicommon_dmaworkaround_req_reset. This is supposed to be called
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* with an user-supplied function as an argument. If both DMA channels are idle, this call will reset the DMA subsystem and return true.
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* 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
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* DMA subsystem and call the callback. The callback is then supposed to be used to continue the SPI drivers activity.
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*
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* @param dmachan DMA channel associated with the SPI host that needs a reset
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* @param cb Callback to call in case DMA channel cannot be reset immediately
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* @param arg Argument to the callback
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*
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* @return True when a DMA reset could be executed immediately. False when it could not; in this
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* case the callback will be called with the specified argument when the logic can execute
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* a reset, after that reset.
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*/
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bool spicommon_dmaworkaround_req_reset(int dmachan, dmaworkaround_cb_t cb, void *arg);
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/**
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* @brief Check if a DMA reset is requested but has not completed yet
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*
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* @return True when a DMA reset is requested but hasn't completed yet. False otherwise.
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*/
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bool spicommon_dmaworkaround_reset_in_progress();
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/**
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* @brief Mark a DMA channel as idle.
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*
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* A call to this function tells the workaround logic that this channel will
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* not be affected by a global SPI DMA reset.
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*/
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void spicommon_dmaworkaround_idle(int dmachan);
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/**
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* @brief Mark a DMA channel as active.
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*
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* A call to this function tells the workaround logic that this channel will
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* be affected by a global SPI DMA reset, and a reset like that should not be attempted.
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*/
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void spicommon_dmaworkaround_transfer_active(int dmachan);
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#ifdef __cplusplus
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}
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#endif
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#endif
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