esp-idf/components/driver/spi_slave.c

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15 KiB
C

// Copyright 2015-2018 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <string.h>
#include "sdkconfig.h"
#include <hal/spi_ll.h>
#include <hal/spi_slave_hal.h>
#include <soc/lldesc.h>
#include "driver/spi_common_internal.h"
#include "driver/spi_slave.h"
#include "soc/spi_periph.h"
#include "soc/gpio_caps.h"
#include "esp_types.h"
#include "esp_attr.h"
#include "esp_intr_alloc.h"
#include "esp_log.h"
#include "esp_err.h"
#include "esp_pm.h"
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#include "freertos/xtensa_api.h"
#include "freertos/task.h"
#include "soc/soc_memory_layout.h"
#include "driver/gpio.h"
#include "esp_heap_caps.h"
#include "esp_rom_gpio.h"
static const char *SPI_TAG = "spi_slave";
#define SPI_CHECK(a, str, ret_val) \
if (!(a)) { \
ESP_LOGE(SPI_TAG,"%s(%d): %s", __FUNCTION__, __LINE__, str); \
return (ret_val); \
}
#ifdef CONFIG_SPI_SLAVE_ISR_IN_IRAM
#define SPI_SLAVE_ISR_ATTR IRAM_ATTR
#else
#define SPI_SLAVE_ISR_ATTR
#endif
#ifdef CONFIG_SPI_SLAVE_IN_IRAM
#define SPI_SLAVE_ATTR IRAM_ATTR
#else
#define SPI_SLAVE_ATTR
#endif
typedef struct {
int id;
spi_slave_interface_config_t cfg;
intr_handle_t intr;
spi_slave_hal_context_t hal;
spi_slave_transaction_t *cur_trans;
uint32_t flags;
int max_transfer_sz;
QueueHandle_t trans_queue;
QueueHandle_t ret_queue;
int dma_chan;
#ifdef CONFIG_PM_ENABLE
esp_pm_lock_handle_t pm_lock;
#endif
} spi_slave_t;
static spi_slave_t *spihost[SOC_SPI_PERIPH_NUM];
static void IRAM_ATTR spi_intr(void *arg);
static inline bool is_valid_host(spi_host_device_t host)
{
#if CONFIG_IDF_TARGET_ESP32
return host >= SPI1_HOST && host <= SPI3_HOST;
#elif CONFIG_IDF_TARGET_ESP32S2
// SPI_HOST (SPI1_HOST) is not supported by the SPI Slave driver on ESP32-S2
return host >= SPI2_HOST && host <= SPI3_HOST;
#endif
}
static inline bool bus_is_iomux(spi_slave_t *host)
{
return host->flags&SPICOMMON_BUSFLAG_IOMUX_PINS;
}
static void freeze_cs(spi_slave_t *host)
{
esp_rom_gpio_connect_in_signal(GPIO_MATRIX_CONST_ONE_INPUT, spi_periph_signal[host->id].spics_in, false);
}
// Use this function instead of cs_initial to avoid overwrite the output config
// This is used in test by internal gpio matrix connections
static inline void restore_cs(spi_slave_t *host)
{
if (bus_is_iomux(host)) {
gpio_iomux_in(host->cfg.spics_io_num, spi_periph_signal[host->id].spics_in);
} else {
esp_rom_gpio_connect_in_signal(host->cfg.spics_io_num, spi_periph_signal[host->id].spics_in, false);
}
}
esp_err_t spi_slave_initialize(spi_host_device_t host, const spi_bus_config_t *bus_config, const spi_slave_interface_config_t *slave_config, int dma_chan)
{
bool spi_chan_claimed, dma_chan_claimed;
esp_err_t ret = ESP_OK;
esp_err_t err;
//We only support HSPI/VSPI, period.
SPI_CHECK(is_valid_host(host), "invalid host", ESP_ERR_INVALID_ARG);
#if defined(CONFIG_IDF_TARGET_ESP32)
SPI_CHECK( dma_chan >= 0 && dma_chan <= 2, "invalid dma channel", ESP_ERR_INVALID_ARG );
#elif defined(CONFIG_IDF_TARGET_ESP32S2)
SPI_CHECK( dma_chan == 0 || dma_chan == host, "invalid dma channel", ESP_ERR_INVALID_ARG );
#endif
SPI_CHECK((bus_config->intr_flags & (ESP_INTR_FLAG_HIGH|ESP_INTR_FLAG_EDGE|ESP_INTR_FLAG_INTRDISABLED))==0, "intr flag not allowed", ESP_ERR_INVALID_ARG);
#ifndef CONFIG_SPI_SLAVE_ISR_IN_IRAM
SPI_CHECK((bus_config->intr_flags & ESP_INTR_FLAG_IRAM)==0, "ESP_INTR_FLAG_IRAM should be disabled when CONFIG_SPI_SLAVE_ISR_IN_IRAM is not set.", ESP_ERR_INVALID_ARG);
#endif
spi_chan_claimed=spicommon_periph_claim(host, "spi slave");
SPI_CHECK(spi_chan_claimed, "host already in use", ESP_ERR_INVALID_STATE);
bool use_dma = dma_chan != 0;
if (use_dma) {
dma_chan_claimed=spicommon_dma_chan_claim(dma_chan);
if ( !dma_chan_claimed ) {
spicommon_periph_free( host );
SPI_CHECK(dma_chan_claimed, "dma channel already in use", ESP_ERR_INVALID_STATE);
}
}
spihost[host] = malloc(sizeof(spi_slave_t));
if (spihost[host] == NULL) {
ret = ESP_ERR_NO_MEM;
goto cleanup;
}
memset(spihost[host], 0, sizeof(spi_slave_t));
memcpy(&spihost[host]->cfg, slave_config, sizeof(spi_slave_interface_config_t));
spihost[host]->id = host;
err = spicommon_bus_initialize_io(host, bus_config, dma_chan, SPICOMMON_BUSFLAG_SLAVE|bus_config->flags, &spihost[host]->flags);
if (err!=ESP_OK) {
ret = err;
goto cleanup;
}
spicommon_cs_initialize(host, slave_config->spics_io_num, 0, !bus_is_iomux(spihost[host]));
// The slave DMA suffers from unexpected transactions. Forbid reading if DMA is enabled by disabling the CS line.
if (use_dma) freeze_cs(spihost[host]);
int dma_desc_ct = 0;
spihost[host]->dma_chan = dma_chan;
if (use_dma) {
//See how many dma descriptors we need and allocate them
dma_desc_ct = (bus_config->max_transfer_sz + SPI_MAX_DMA_LEN - 1) / SPI_MAX_DMA_LEN;
if (dma_desc_ct == 0) dma_desc_ct = 1; //default to 4k when max is not given
spihost[host]->max_transfer_sz = dma_desc_ct * SPI_MAX_DMA_LEN;
} else {
//We're limited to non-DMA transfers: the SPI work registers can hold 64 bytes at most.
spihost[host]->max_transfer_sz = SOC_SPI_MAXIMUM_BUFFER_SIZE;
}
#ifdef CONFIG_PM_ENABLE
err = esp_pm_lock_create(ESP_PM_APB_FREQ_MAX, 0, "spi_slave",
&spihost[host]->pm_lock);
if (err != ESP_OK) {
ret = err;
goto cleanup;
}
// Lock APB frequency while SPI slave driver is in use
esp_pm_lock_acquire(spihost[host]->pm_lock);
#endif //CONFIG_PM_ENABLE
//Create queues
spihost[host]->trans_queue = xQueueCreate(slave_config->queue_size, sizeof(spi_slave_transaction_t *));
spihost[host]->ret_queue = xQueueCreate(slave_config->queue_size, sizeof(spi_slave_transaction_t *));
if (!spihost[host]->trans_queue || !spihost[host]->ret_queue) {
ret = ESP_ERR_NO_MEM;
goto cleanup;
}
int flags = bus_config->intr_flags | ESP_INTR_FLAG_INTRDISABLED;
err = esp_intr_alloc(spicommon_irqsource_for_host(host), flags, spi_intr, (void *)spihost[host], &spihost[host]->intr);
if (err != ESP_OK) {
ret = err;
goto cleanup;
}
spi_slave_hal_context_t *hal = &spihost[host]->hal;
spi_slave_hal_init(hal, host);
if (dma_desc_ct) {
hal->dmadesc_tx = heap_caps_malloc(sizeof(lldesc_t) * dma_desc_ct, MALLOC_CAP_DMA);
hal->dmadesc_rx = heap_caps_malloc(sizeof(lldesc_t) * dma_desc_ct, MALLOC_CAP_DMA);
if (!hal->dmadesc_tx || !hal->dmadesc_rx) {
ret = ESP_ERR_NO_MEM;
goto cleanup;
}
}
hal->dmadesc_n = dma_desc_ct;
hal->rx_lsbfirst = (slave_config->flags & SPI_SLAVE_RXBIT_LSBFIRST) ? 1 : 0;
hal->tx_lsbfirst = (slave_config->flags & SPI_SLAVE_TXBIT_LSBFIRST) ? 1 : 0;
hal->mode = slave_config->mode;
hal->use_dma = use_dma;
spi_slave_hal_setup_device(hal);
return ESP_OK;
cleanup:
if (spihost[host]) {
if (spihost[host]->trans_queue) vQueueDelete(spihost[host]->trans_queue);
if (spihost[host]->ret_queue) vQueueDelete(spihost[host]->ret_queue);
free(spihost[host]->hal.dmadesc_tx);
free(spihost[host]->hal.dmadesc_rx);
#ifdef CONFIG_PM_ENABLE
if (spihost[host]->pm_lock) {
esp_pm_lock_release(spihost[host]->pm_lock);
esp_pm_lock_delete(spihost[host]->pm_lock);
}
#endif
}
spi_slave_hal_deinit(&spihost[host]->hal);
free(spihost[host]);
spihost[host] = NULL;
spicommon_periph_free(host);
if (dma_chan != 0) spicommon_dma_chan_free(dma_chan);
return ret;
}
esp_err_t spi_slave_free(spi_host_device_t host)
{
SPI_CHECK(is_valid_host(host), "invalid host", ESP_ERR_INVALID_ARG);
SPI_CHECK(spihost[host], "host not slave", ESP_ERR_INVALID_ARG);
if (spihost[host]->trans_queue) vQueueDelete(spihost[host]->trans_queue);
if (spihost[host]->ret_queue) vQueueDelete(spihost[host]->ret_queue);
if ( spihost[host]->dma_chan > 0 ) {
spicommon_dma_chan_free ( spihost[host]->dma_chan );
}
free(spihost[host]->hal.dmadesc_tx);
free(spihost[host]->hal.dmadesc_rx);
esp_intr_free(spihost[host]->intr);
#ifdef CONFIG_PM_ENABLE
esp_pm_lock_release(spihost[host]->pm_lock);
esp_pm_lock_delete(spihost[host]->pm_lock);
#endif //CONFIG_PM_ENABLE
free(spihost[host]);
spihost[host] = NULL;
spicommon_periph_free(host);
return ESP_OK;
}
esp_err_t SPI_SLAVE_ATTR spi_slave_queue_trans(spi_host_device_t host, const spi_slave_transaction_t *trans_desc, TickType_t ticks_to_wait)
{
BaseType_t r;
SPI_CHECK(is_valid_host(host), "invalid host", ESP_ERR_INVALID_ARG);
SPI_CHECK(spihost[host], "host not slave", ESP_ERR_INVALID_ARG);
SPI_CHECK(spihost[host]->dma_chan == 0 || trans_desc->tx_buffer==NULL || esp_ptr_dma_capable(trans_desc->tx_buffer),
"txdata not in DMA-capable memory", ESP_ERR_INVALID_ARG);
SPI_CHECK(spihost[host]->dma_chan == 0 || trans_desc->rx_buffer==NULL ||
(esp_ptr_dma_capable(trans_desc->rx_buffer) && esp_ptr_word_aligned(trans_desc->rx_buffer) &&
(trans_desc->length%4==0)),
"rxdata not in DMA-capable memory or not WORD aligned", ESP_ERR_INVALID_ARG);
SPI_CHECK(trans_desc->length <= spihost[host]->max_transfer_sz * 8, "data transfer > host maximum", ESP_ERR_INVALID_ARG);
r = xQueueSend(spihost[host]->trans_queue, (void *)&trans_desc, ticks_to_wait);
if (!r) return ESP_ERR_TIMEOUT;
esp_intr_enable(spihost[host]->intr);
return ESP_OK;
}
esp_err_t SPI_SLAVE_ATTR spi_slave_get_trans_result(spi_host_device_t host, spi_slave_transaction_t **trans_desc, TickType_t ticks_to_wait)
{
BaseType_t r;
SPI_CHECK(is_valid_host(host), "invalid host", ESP_ERR_INVALID_ARG);
SPI_CHECK(spihost[host], "host not slave", ESP_ERR_INVALID_ARG);
r = xQueueReceive(spihost[host]->ret_queue, (void *)trans_desc, ticks_to_wait);
if (!r) return ESP_ERR_TIMEOUT;
return ESP_OK;
}
esp_err_t SPI_SLAVE_ATTR spi_slave_transmit(spi_host_device_t host, spi_slave_transaction_t *trans_desc, TickType_t ticks_to_wait)
{
esp_err_t ret;
spi_slave_transaction_t *ret_trans;
//ToDo: check if any spi transfers in flight
ret = spi_slave_queue_trans(host, trans_desc, ticks_to_wait);
if (ret != ESP_OK) return ret;
ret = spi_slave_get_trans_result(host, &ret_trans, ticks_to_wait);
if (ret != ESP_OK) return ret;
assert(ret_trans == trans_desc);
return ESP_OK;
}
#ifdef DEBUG_SLAVE
static void dumpregs(spi_dev_t *hw)
{
ets_printf("***REG DUMP ***\n");
ets_printf("mosi_dlen : %08X\n", hw->mosi_dlen.val);
ets_printf("miso_dlen : %08X\n", hw->miso_dlen.val);
ets_printf("slv_wrbuf_dlen : %08X\n", hw->slv_wrbuf_dlen.val);
ets_printf("slv_rdbuf_dlen : %08X\n", hw->slv_rdbuf_dlen.val);
ets_printf("slave : %08X\n", hw->slave.val);
ets_printf("slv_rdata_bit : %x\n", hw->slv_rd_bit.slv_rdata_bit);
ets_printf("dma_rx_status : %08X\n", hw->dma_rx_status);
ets_printf("dma_tx_status : %08X\n", hw->dma_tx_status);
}
static void dumpll(lldesc_t *ll)
{
ets_printf("****LL DUMP****\n");
ets_printf("Size %d\n", ll->size);
ets_printf("Len: %d\n", ll->length);
ets_printf("Owner: %s\n", ll->owner ? "dma" : "cpu");
}
#endif
static void SPI_SLAVE_ISR_ATTR spi_slave_restart_after_dmareset(void *arg)
{
spi_slave_t *host = (spi_slave_t *)arg;
esp_intr_enable(host->intr);
}
//This is run in interrupt context and apart from initialization and destruction, this is the only code
//touching the host (=spihost[x]) variable. The rest of the data arrives in queues. That is why there are
//no muxes in this code.
static void SPI_SLAVE_ISR_ATTR spi_intr(void *arg)
{
BaseType_t r;
BaseType_t do_yield = pdFALSE;
spi_slave_transaction_t *trans = NULL;
spi_slave_t *host = (spi_slave_t *)arg;
spi_slave_hal_context_t *hal = &host->hal;
#ifdef DEBUG_SLAVE
dumpregs(host->hw);
if (host->dmadesc_rx) dumpll(&host->dmadesc_rx[0]);
#endif
assert(spi_slave_hal_usr_is_done(hal));
bool use_dma = host->dma_chan != 0;
if (host->cur_trans) {
// When DMA is enabled, the slave rx dma suffers from unexpected transactions. Forbid reading until transaction ready.
if (use_dma) freeze_cs(host);
spi_slave_hal_store_result(hal);
host->cur_trans->trans_len = spi_slave_hal_get_rcv_bitlen(hal);
if (spi_slave_hal_dma_need_reset(hal)) {
spicommon_dmaworkaround_req_reset(host->dma_chan, spi_slave_restart_after_dmareset, host);
}
if (host->cfg.post_trans_cb) host->cfg.post_trans_cb(host->cur_trans);
//Okay, transaction is done.
//Return transaction descriptor.
xQueueSendFromISR(host->ret_queue, &host->cur_trans, &do_yield);
host->cur_trans = NULL;
}
if (use_dma) {
spicommon_dmaworkaround_idle(host->dma_chan);
if (spicommon_dmaworkaround_reset_in_progress()) {
//We need to wait for the reset to complete. Disable int (will be re-enabled on reset callback) and exit isr.
esp_intr_disable(host->intr);
if (do_yield) portYIELD_FROM_ISR();
return;
}
}
//Disable interrupt before checking to avoid concurrency issue.
esp_intr_disable(host->intr);
//Grab next transaction
r = xQueueReceiveFromISR(host->trans_queue, &trans, &do_yield);
if (r) {
//enable the interrupt again if there is packet to send
esp_intr_enable(host->intr);
//We have a transaction. Send it.
host->cur_trans = trans;
hal->bitlen = trans->length;
hal->rx_buffer = trans->rx_buffer;
hal->tx_buffer = trans->tx_buffer;
if (use_dma) {
spicommon_dmaworkaround_transfer_active(host->dma_chan);
}
spi_slave_hal_prepare_data(hal);
//The slave rx dma get disturbed by unexpected transaction. Only connect the CS when slave is ready.
if (use_dma) {
restore_cs(host);
}
//Kick off transfer
spi_slave_hal_user_start(hal);
if (host->cfg.post_setup_cb) host->cfg.post_setup_cb(trans);
}
if (do_yield) portYIELD_FROM_ISR();
}