esp-idf/components/driver/spi_slave.c

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20 KiB
C
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// 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 "driver/spi_common.h"
#include "driver/spi_slave.h"
#include "soc/dport_reg.h"
#include "soc/spi_periph.h"
#include "rom/ets_sys.h"
#include "esp_types.h"
#include "esp_attr.h"
#include "esp_intr.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.h"
#include "soc/soc_memory_layout.h"
#include "soc/dport_reg.h"
#include "rom/lldesc.h"
#include "driver/gpio.h"
#include "driver/periph_ctrl.h"
#include "esp_heap_caps.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); \
}
#define VALID_HOST(x) (x>SPI_HOST && x<=VSPI_HOST)
#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_dev_t *hw;
spi_slave_transaction_t *cur_trans;
lldesc_t *dmadesc_tx;
lldesc_t *dmadesc_rx;
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[3];
static void IRAM_ATTR spi_intr(void *arg);
static inline bool bus_is_iomux(spi_slave_t *host)
{
return host->flags&SPICOMMON_BUSFLAG_NATIVE_PINS;
}
static void freeze_cs(spi_slave_t *host)
{
gpio_matrix_in(GPIO_FUNC_IN_HIGH, 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 {
gpio_matrix_in(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(VALID_HOST(host), "invalid host", ESP_ERR_INVALID_ARG);
SPI_CHECK( dma_chan >= 0 && dma_chan <= 2, "invalid dma channel", ESP_ERR_INVALID_ARG );
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);
if ( dma_chan != 0 ) {
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);
}
}
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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 (dma_chan != 0) freeze_cs(spihost[host]);
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spihost[host]->dma_chan = dma_chan;
if (dma_chan != 0) {
//See how many dma descriptors we need and allocate them
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int 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;
spihost[host]->dmadesc_tx = heap_caps_malloc(sizeof(lldesc_t) * dma_desc_ct, MALLOC_CAP_DMA);
spihost[host]->dmadesc_rx = heap_caps_malloc(sizeof(lldesc_t) * dma_desc_ct, MALLOC_CAP_DMA);
if (!spihost[host]->dmadesc_tx || !spihost[host]->dmadesc_rx) {
ret = ESP_ERR_NO_MEM;
goto cleanup;
}
} else {
//We're limited to non-DMA transfers: the SPI work registers can hold 64 bytes at most.
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spihost[host]->max_transfer_sz = 16 * 4;
}
#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
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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;
}
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spihost[host]->hw = spicommon_hw_for_host(host);
//Configure slave
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spihost[host]->hw->clock.val = 0;
spihost[host]->hw->user.val = 0;
spihost[host]->hw->ctrl.val = 0;
spihost[host]->hw->slave.wr_rd_buf_en = 1; //no sure if needed
spihost[host]->hw->user.doutdin = 1; //we only support full duplex
spihost[host]->hw->user.sio = 0;
spihost[host]->hw->slave.slave_mode = 1;
spihost[host]->hw->dma_conf.val |= SPI_OUT_RST | SPI_IN_RST | SPI_AHBM_RST | SPI_AHBM_FIFO_RST;
spihost[host]->hw->dma_out_link.start = 0;
spihost[host]->hw->dma_in_link.start = 0;
spihost[host]->hw->dma_conf.val &= ~(SPI_OUT_RST | SPI_IN_RST | SPI_AHBM_RST | SPI_AHBM_FIFO_RST);
spihost[host]->hw->dma_conf.out_data_burst_en = 1;
spihost[host]->hw->slave.sync_reset = 1;
spihost[host]->hw->slave.sync_reset = 0;
bool nodelay = true;
spihost[host]->hw->ctrl.rd_bit_order = (slave_config->flags & SPI_SLAVE_RXBIT_LSBFIRST) ? 1 : 0;
spihost[host]->hw->ctrl.wr_bit_order = (slave_config->flags & SPI_SLAVE_TXBIT_LSBFIRST) ? 1 : 0;
if (slave_config->mode == 0) {
spihost[host]->hw->pin.ck_idle_edge = 0;
spihost[host]->hw->user.ck_i_edge = 1;
spihost[host]->hw->ctrl2.miso_delay_mode = nodelay ? 0 : 2;
} else if (slave_config->mode == 1) {
spihost[host]->hw->pin.ck_idle_edge = 0;
spihost[host]->hw->user.ck_i_edge = 0;
spihost[host]->hw->ctrl2.miso_delay_mode = nodelay ? 0 : 1;
} else if (slave_config->mode == 2) {
spihost[host]->hw->pin.ck_idle_edge = 1;
spihost[host]->hw->user.ck_i_edge = 0;
spihost[host]->hw->ctrl2.miso_delay_mode = nodelay ? 0 : 1;
} else if (slave_config->mode == 3) {
spihost[host]->hw->pin.ck_idle_edge = 1;
spihost[host]->hw->user.ck_i_edge = 1;
spihost[host]->hw->ctrl2.miso_delay_mode = nodelay ? 0 : 2;
}
//Reset DMA
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spihost[host]->hw->dma_conf.val |= SPI_OUT_RST | SPI_IN_RST | SPI_AHBM_RST | SPI_AHBM_FIFO_RST;
spihost[host]->hw->dma_out_link.start = 0;
spihost[host]->hw->dma_in_link.start = 0;
spihost[host]->hw->dma_conf.val &= ~(SPI_OUT_RST | SPI_IN_RST | SPI_AHBM_RST | SPI_AHBM_FIFO_RST);
//Disable unneeded ints
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spihost[host]->hw->slave.rd_buf_done = 0;
spihost[host]->hw->slave.wr_buf_done = 0;
spihost[host]->hw->slave.rd_sta_done = 0;
spihost[host]->hw->slave.wr_sta_done = 0;
spihost[host]->hw->slave.rd_buf_inten = 0;
spihost[host]->hw->slave.wr_buf_inten = 0;
spihost[host]->hw->slave.rd_sta_inten = 0;
spihost[host]->hw->slave.wr_sta_inten = 0;
//Force a transaction done interrupt. This interrupt won't fire yet because we initialized the SPI interrupt as
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//disabled. This way, we can just enable the SPI interrupt and the interrupt handler will kick in, handling
//any transactions that are queued.
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spihost[host]->hw->slave.trans_inten = 1;
spihost[host]->hw->slave.trans_done = 1;
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]->dmadesc_tx);
free(spihost[host]->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
}
free(spihost[host]);
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spihost[host] = NULL;
spicommon_periph_free(host);
spicommon_dma_chan_free(dma_chan);
return ret;
}
esp_err_t spi_slave_free(spi_host_device_t host)
{
SPI_CHECK(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]->dmadesc_tx);
free(spihost[host]->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]);
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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(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),
"rxdata not in DMA-capable memory", ESP_ERR_INVALID_ARG);
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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(VALID_HOST(host), "invalid host", ESP_ERR_INVALID_ARG);
SPI_CHECK(spihost[host], "host not slave", ESP_ERR_INVALID_ARG);
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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
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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
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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);
}
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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);
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ets_printf("Owner: %s\n", ll->owner ? "dma" : "cpu");
}
#endif
static void SPI_SLAVE_ISR_ATTR spi_slave_restart_after_dmareset(void *arg)
{
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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;
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BaseType_t do_yield = pdFALSE;
spi_slave_transaction_t *trans = NULL;
spi_slave_t *host = (spi_slave_t *)arg;
#ifdef DEBUG_SLAVE
dumpregs(host->hw);
if (host->dmadesc_rx) dumpll(&host->dmadesc_rx[0]);
#endif
//Ignore all but the trans_done int.
if (!host->hw->slave.trans_done) return;
if (host->cur_trans) {
// When DMA is enabled, the slave rx dma suffers from unexpected transactions. Forbid reading until transaction ready.
if (host->dma_chan != 0) freeze_cs(host);
//when data of cur_trans->length are all sent, the slv_rdata_bit
//will be the length sent-1 (i.e. cur_trans->length-1 ), otherwise
//the length sent.
host->cur_trans->trans_len = host->hw->slv_rd_bit.slv_rdata_bit;
if (host->cur_trans->trans_len == host->cur_trans->length - 1) {
host->cur_trans->trans_len++;
}
if (host->dma_chan == 0 && host->cur_trans->rx_buffer) {
//Copy result out
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uint32_t *data = host->cur_trans->rx_buffer;
for (int x = 0; x < host->cur_trans->trans_len; x += 32) {
uint32_t word;
int len = host->cur_trans->trans_len - x;
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if (len > 32) len = 32;
word = host->hw->data_buf[(x / 32)];
memcpy(&data[x / 32], &word, (len + 7) / 8);
}
} else if (host->dma_chan != 0 && host->cur_trans->rx_buffer) {
int i;
//In case CS goes high too soon, the transfer is aborted while the DMA channel still thinks it's going. This
//leads to issues later on, so in that case we need to reset the channel. The state can be detected because
//the DMA system doesn't give back the offending descriptor; the owner is still set to DMA.
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for (i = 0; host->dmadesc_rx[i].eof == 0 && host->dmadesc_rx[i].owner == 0; i++) ;
if (host->dmadesc_rx[i].owner) {
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);
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host->cur_trans = NULL;
}
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if (host->dma_chan != 0) {
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;
}
}
//Grab next transaction
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r = xQueueReceiveFromISR(host->trans_queue, &trans, &do_yield);
if (!r) {
//No packet waiting. Disable interrupt.
esp_intr_disable(host->intr);
} else {
//We have a transaction. Send it.
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host->hw->slave.trans_done = 0; //clear int bit
host->cur_trans = trans;
if (host->dma_chan != 0) {
spicommon_dmaworkaround_transfer_active(host->dma_chan);
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host->hw->dma_conf.val |= SPI_OUT_RST | SPI_IN_RST | SPI_AHBM_RST | SPI_AHBM_FIFO_RST;
host->hw->dma_out_link.start = 0;
host->hw->dma_in_link.start = 0;
host->hw->dma_conf.val &= ~(SPI_OUT_RST | SPI_IN_RST | SPI_AHBM_RST | SPI_AHBM_FIFO_RST);
host->hw->dma_conf.out_data_burst_en = 0;
host->hw->dma_conf.indscr_burst_en = 0;
host->hw->dma_conf.outdscr_burst_en = 0;
//Fill DMA descriptors
if (trans->rx_buffer) {
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host->hw->user.usr_miso_highpart = 0;
spicommon_setup_dma_desc_links(host->dmadesc_rx, ((trans->length + 7) / 8), trans->rx_buffer, true);
host->hw->dma_in_link.addr = (int)(&host->dmadesc_rx[0]) & 0xFFFFF;
host->hw->dma_in_link.start = 1;
}
if (trans->tx_buffer) {
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spicommon_setup_dma_desc_links(host->dmadesc_tx, (trans->length + 7) / 8, trans->tx_buffer, false);
host->hw->user.usr_mosi_highpart = 0;
host->hw->dma_out_link.addr = (int)(&host->dmadesc_tx[0]) & 0xFFFFF;
host->hw->dma_out_link.start = 1;
}
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host->hw->slave.sync_reset = 1;
host->hw->slave.sync_reset = 0;
} else {
//No DMA. Turn off SPI and copy data to transmit buffers.
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host->hw->cmd.usr = 0;
host->hw->slave.sync_reset = 1;
host->hw->slave.sync_reset = 0;
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host->hw->user.usr_miso_highpart = 0;
host->hw->user.usr_mosi_highpart = 0;
if (trans->tx_buffer) {
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const uint32_t *data = host->cur_trans->tx_buffer;
for (int x = 0; x < trans->length; x += 32) {
uint32_t word;
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memcpy(&word, &data[x / 32], 4);
host->hw->data_buf[(x / 32)] = word;
}
}
}
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host->hw->slv_rd_bit.slv_rdata_bit = 0;
host->hw->slv_wrbuf_dlen.bit_len = trans->length - 1;
host->hw->slv_rdbuf_dlen.bit_len = trans->length - 1;
host->hw->mosi_dlen.usr_mosi_dbitlen = trans->length - 1;
host->hw->miso_dlen.usr_miso_dbitlen = trans->length - 1;
host->hw->user.usr_mosi = (trans->tx_buffer == NULL) ? 0 : 1;
host->hw->user.usr_miso = (trans->rx_buffer == NULL) ? 0 : 1;
//The slave rx dma get disturbed by unexpected transaction. Only connect the CS when slave is ready.
if (host->dma_chan != 0) restore_cs(host);
//Kick off transfer
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host->hw->cmd.usr = 1;
if (host->cfg.post_setup_cb) host->cfg.post_setup_cb(trans);
}
if (do_yield) portYIELD_FROM_ISR();
}