1 files changed, 411 insertions, 0 deletions
diff --git a/yocto/esp32d/spi.c b/yocto/esp32d/spi.c
new file mode 100644
index 0000000..db46a63
--- /dev/null
+++ b/yocto/esp32d/spi.c
@@ -0,0 +1,411 @@
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+#include <linux/spi/spidev.h>
+
+#include <gpiod.h>
+#include <pthread.h>
+
+#include "msgq.h"
+#include "tun.h"
+#include "spi.h"
+
+static pthread_t worker_thd;
+static pthread_t rtscts_thd;
+static pthread_t msg_handler_thd;
+static pthread_t tun_handler_thd;
+static pthread_mutex_t mutex;
+static pthread_cond_t cond;
+
+static MSGQueue spi_bufq;
+static unsigned char *spi_bufq_array[SPI_SIZE_BUFQ];
+
+static MSGQueue spi_msgq_in;
+static unsigned char *spi_msgq_in_array[SPI_SIZE_MSGQ_IN];
+
+static MSGQueue spi_msgq_out;
+static unsigned char *spi_msgq_out_array[SPI_SIZE_MSGQ_OUT];
+
+static uint32_t spi_speed = SPI_SPEED;
+static int spi_fd;
+static volatile int spi_cts;
+
+struct gpiod_line_request *request = NULL;
+
+static void _spi_wait4cts(void) {
+    pthread_mutex_lock(&mutex);
+    while (!spi_cts) {
+        pthread_cond_wait(&cond, &mutex);
+    }
+    spi_cts = 0;
+    pthread_mutex_unlock(&mutex);
+}
+
+static int _spi_xchg(unsigned char *buffer) {
+    int rv;
+    uint16_t len_tx;
+    uint16_t len_rx;
+    struct spi_ioc_transfer tr;
+
+    memset(&tr, 0, sizeof(tr));
+    tr.tx_buf = (unsigned long)buffer;
+    tr.rx_buf = (unsigned long)buffer;
+    tr.speed_hz = spi_speed;
+
+    len_tx  = (uint16_t)buffer[1] << 8;
+    len_tx |= (uint16_t)buffer[2] & 0xFF;
+    if (len_tx > SPI_MTU) return SPI_ERR;
+
+    if (buffer[0]) {
+        len_tx += SPI_SIZE_HDR;
+        // esp32 dma workaraund
+        if (len_tx < 8) {
+            len_tx = 8;
+        } else if (len_tx % 4 != 0) {
+            len_tx = (len_tx / 4 + 1) * 4;
+        }
+
+        tr.len = len_tx;
+    } else {
+        /* nothing to send, reset esp32 spi transaction */
+        tr.len = 1;
+
+        _spi_wait4cts();
+        rv = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr);
+        if (rv < 0) return SPI_ERR_MSG;
+
+        /* receive SPI_SIZE_RECEIVE bytes in first transaction (estimate) */
+        len_tx = SPI_SIZE_RECEIVE + SPI_SIZE_HDR;
+        tr.len = len_tx;
+        buffer[1] = 0;
+        buffer[2] = 0;
+    }
+
+    _spi_wait4cts();
+    rv = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr);
+    if (rv < 0) return SPI_ERR_MSG;
+
+    len_rx  = (uint16_t)buffer[1] << 8;
+    len_rx |= (uint16_t)buffer[2] & 0xFF;
+    if (len_rx > SPI_MTU) return SPI_ERR;
+
+    len_rx += SPI_SIZE_HDR;
+    if (len_rx > len_tx) {
+        tr.tx_buf = (unsigned long)NULL;
+        tr.rx_buf = (unsigned long)(buffer + len_tx);
+
+        len_tx = len_rx - len_tx;
+        // esp32 dma workaraund
+        if (len_tx < 8) {
+            len_tx = 8;
+        } else if (len_tx % 4 != 0) {
+            len_tx = (len_tx / 4 + 1) * 4;
+        }
+
+        tr.len = len_tx;
+
+        _spi_wait4cts();
+        rv = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr);
+        if (rv < 0) return SPI_ERR_MSG;
+    }
+
+    return SPI_OK;
+}
+
+static void *worker(void *arg) {
+    MSGQueue *bufq = &spi_bufq;
+    MSGQueue *msgq_in = &spi_msgq_in;
+    MSGQueue *msgq_out = &spi_msgq_out;
+    int rv;
+    unsigned char *buffer;
+
+    while (1) {
+        pthread_mutex_lock(&msgq_out->mutex);
+        buffer = msgq_pop(msgq_out);
+        if ((buffer == NULL) && (gpiod_line_request_get_value(request, SPI_GPIO_RTS) == GPIOD_LINE_VALUE_INACTIVE)) {
+            pthread_mutex_lock(&bufq->mutex);
+            buffer = msgq_pop(bufq);
+            pthread_mutex_unlock(&bufq->mutex);
+        }
+        if (buffer == NULL) {
+            pthread_cond_wait(&msgq_out->cond, &msgq_out->mutex);
+            buffer = msgq_pop(msgq_out);
+        }
+        pthread_mutex_unlock(&msgq_out->mutex);
+        if (buffer) {
+            rv = _spi_xchg(buffer);
+            if (rv || (buffer[0] == 0)) {
+                buffer[0] = 0;
+                buffer[1] = 0;
+                buffer[2] = 0;
+                pthread_mutex_lock(&bufq->mutex);
+                msgq_push(bufq, buffer);
+                pthread_mutex_unlock(&bufq->mutex);
+            } else {
+                pthread_mutex_lock(&msgq_in->mutex);
+                rv = msgq_push(msgq_in, buffer);
+                if (rv == MSGQ_OK) pthread_cond_signal(&msgq_in->cond);
+                pthread_mutex_unlock(&msgq_in->mutex);
+
+                if (rv) {
+                    pthread_mutex_lock(&bufq->mutex);
+                    msgq_push(bufq, buffer);
+                    pthread_mutex_unlock(&bufq->mutex);
+                }
+            }
+        }
+    }
+
+    return NULL;
+}
+
+static void *rtscts_handler(void *arg) {
+    MSGQueue *msgq_out = &spi_msgq_out;
+    struct gpiod_edge_event_buffer *event_buffer;
+    struct gpiod_edge_event *event;
+    int rv;
+
+    event_buffer = gpiod_edge_event_buffer_new(1);
+
+    while (1) {
+        rv = gpiod_line_request_read_edge_events(request, event_buffer, 1);
+        if (rv != 1) continue;
+
+        event = gpiod_edge_event_buffer_get_event(event_buffer, 0);
+        switch (gpiod_edge_event_get_line_offset(event)) {
+            case SPI_GPIO_RTS: {
+                pthread_mutex_lock(&msgq_out->mutex);
+                pthread_cond_signal(&msgq_out->cond);
+                pthread_mutex_unlock(&msgq_out->mutex);
+                break;
+            }
+
+            case SPI_GPIO_CTS: {
+                pthread_mutex_lock(&mutex);
+                spi_cts = 1;
+                pthread_cond_signal(&cond);
+                pthread_mutex_unlock(&mutex);
+                break;
+            }
+        }
+    }
+
+    gpiod_edge_event_buffer_free(event_buffer);
+    return NULL;
+}
+
+static void *msg_handler(void *arg) {
+    MSGQueue *bufq = &spi_bufq;
+    MSGQueue *msgq_in = &spi_msgq_in;
+    unsigned char *buffer;
+    unsigned char mtype;
+    uint16_t len;
+    int rv;
+
+    while (1) {
+        pthread_mutex_lock(&msgq_in->mutex);
+        buffer = msgq_pop(msgq_in);
+        if (buffer == NULL) {
+            pthread_cond_wait(&msgq_in->cond, &msgq_in->mutex);
+            buffer = msgq_pop(msgq_in);
+        }
+        pthread_mutex_unlock(&msgq_in->mutex);
+        if (buffer) {
+            mtype = buffer[0];
+            len  = (uint16_t)buffer[1] << 8;
+            len |= (uint16_t)buffer[2] & 0xFF;
+
+            switch (mtype) {
+                case SPI_MTYPE_TUN:
+                    tun_write(buffer + SPI_SIZE_HDR, len);
+                    break;
+            }
+            buffer[0] = 0;
+            buffer[1] = 0;
+            buffer[2] = 0;
+            pthread_mutex_lock(&bufq->mutex);
+            msgq_push(bufq, buffer);
+            pthread_mutex_unlock(&bufq->mutex);
+        }
+    }
+
+    return NULL;
+}
+
+static void *tun_handler(void *arg) {
+    unsigned char *buffer;
+    ssize_t len;
+
+    while (1) {
+        buffer = spi_alloc();
+        if (buffer == NULL) continue;
+
+        len = tun_read(buffer + SPI_SIZE_HDR, SPI_SIZE_BUF - SPI_SIZE_HDR);
+        if (len < 0) {
+            perror("tun read");
+            continue;
+        }
+        spi_xchg(SPI_MTYPE_TUN, buffer, len);
+    }
+
+    return NULL;
+}
+
+unsigned char *spi_alloc(void) {
+    MSGQueue *bufq = &spi_bufq;
+    unsigned char *buffer;
+
+    pthread_mutex_lock(&bufq->mutex);
+    buffer = msgq_pop(bufq);
+    pthread_mutex_unlock(&bufq->mutex);
+
+    return buffer;
+}
+
+void spi_free(unsigned char *buffer) {
+    MSGQueue *bufq = &spi_bufq;
+
+    buffer[0] = 0;
+    buffer[1] = 0;
+    buffer[2] = 0;
+    pthread_mutex_lock(&bufq->mutex);
+    msgq_push(bufq, buffer);
+    pthread_mutex_unlock(&bufq->mutex);
+}
+
+int spi_xchg(unsigned char mtype, unsigned char *buffer, uint16_t len) {
+    MSGQueue *bufq = &spi_bufq;
+    MSGQueue *msgq_out = &spi_msgq_out;
+    int rv;
+
+    buffer[0] = mtype;
+    buffer[1] = len >> 8;
+    buffer[2] = len & 0xFF;
+
+    pthread_mutex_lock(&msgq_out->mutex);
+    rv = msgq_push(msgq_out, buffer);
+    if (rv == MSGQ_OK) pthread_cond_signal(&msgq_out->cond);
+    pthread_mutex_unlock(&msgq_out->mutex);
+
+    if (rv) {
+        pthread_mutex_lock(&bufq->mutex);
+        msgq_push(bufq, buffer);
+        pthread_mutex_unlock(&bufq->mutex);
+    }
+
+    return rv;
+}
+
+int gpio_init(void) {
+    struct gpiod_chip *chip = NULL;
+    struct gpiod_line_settings *line_settings = NULL;
+    struct gpiod_line_config *line_cfg = NULL;
+    struct gpiod_request_config *req_cfg = NULL;
+    int rv;
+
+    unsigned int line_offsets[2] = { SPI_GPIO_RTS, SPI_GPIO_CTS };
+
+    chip = gpiod_chip_open(SPI_GPIO_DEV);
+    if (chip == NULL) goto gpio_init_fin;
+
+    line_settings = gpiod_line_settings_new();
+    if (line_settings == NULL) goto gpio_init_fin;
+
+    gpiod_line_settings_set_direction(line_settings, GPIOD_LINE_DIRECTION_INPUT);
+    gpiod_line_settings_set_edge_detection(line_settings, GPIOD_LINE_EDGE_FALLING);
+    gpiod_line_settings_set_bias(line_settings, GPIOD_LINE_BIAS_PULL_UP);
+
+    line_cfg = gpiod_line_config_new();
+    if (line_cfg == NULL) goto gpio_init_fin;
+
+    rv = gpiod_line_config_add_line_settings(line_cfg, line_offsets, 2, line_settings);
+    if (rv) goto gpio_init_fin;
+
+    req_cfg = gpiod_request_config_new();
+    if (req_cfg == NULL) goto gpio_init_fin;
+
+    gpiod_request_config_set_consumer(req_cfg, "rts-cts");
+
+    request = gpiod_chip_request_lines(chip, req_cfg, line_cfg);
+
+gpio_init_fin:
+    rv = (request ? SPI_OK : (chip ? SPI_ERR : SPI_ERR_OPEN));
+
+    if (req_cfg) gpiod_request_config_free(req_cfg);
+    if (line_cfg) gpiod_line_config_free(line_cfg);
+    if (line_settings) gpiod_line_settings_free(line_settings);
+    if (chip) gpiod_chip_close(chip);
+
+    return rv;
+}
+
+int spi_init(void) {
+    unsigned char *buffer;
+    int rv, i;
+
+    spi_fd = open(SPI_DEV, O_RDWR);
+    if (spi_fd < 0) return SPI_ERR_OPEN;
+
+    rv = ioctl(spi_fd, SPI_IOC_WR_MAX_SPEED_HZ, &spi_speed);
+    if (rv == -1) return SPI_ERR;
+
+    rv = msgq_init(&spi_bufq, spi_bufq_array, SPI_SIZE_BUFQ);
+    assert(rv == MSGQ_OK);
+
+    rv = msgq_init(&spi_msgq_in, spi_msgq_in_array, SPI_SIZE_MSGQ_IN);
+    assert(rv == MSGQ_OK);
+
+    rv = msgq_init(&spi_msgq_out, spi_msgq_out_array, SPI_SIZE_MSGQ_OUT);
+    assert(rv == MSGQ_OK);
+
+    for (i=0; i<SPI_SIZE_BUFQ; i++) {
+        buffer = malloc(SPI_SIZE_BUF);
+        assert(buffer);
+        msgq_push(&spi_bufq, buffer);
+    }
+
+    rv = pthread_mutex_init(&mutex, NULL);
+    assert(rv == 0);
+
+    rv = pthread_cond_init(&cond, NULL);
+    assert(rv == 0);
+
+    /* assret initial contitions */
+    pthread_mutex_lock(&mutex);
+    spi_cts = (gpiod_line_request_get_value(request, SPI_GPIO_CTS) == GPIOD_LINE_VALUE_INACTIVE);
+    pthread_mutex_unlock(&mutex);
+
+    rv = pthread_create(&worker_thd, NULL, worker, NULL);
+    assert(rv == 0);
+
+    rv = pthread_create(&rtscts_thd, NULL, rtscts_handler, NULL);
+    assert(rv == 0);
+
+    rv = pthread_create(&msg_handler_thd, NULL, msg_handler, NULL);
+    assert(rv == 0);
+
+    rv = pthread_create(&tun_handler_thd, NULL, tun_handler, NULL);
+    assert(rv == 0);
+
+    return SPI_OK;
+}
+
+int main(int argc, char *argv[]) {
+    int rv;
+
+    rv = tun_init(SPI_TUN_NAME);
+    if (rv) printf("TUN INIT ERR\n");
+
+    rv = gpio_init();
+    if (rv) printf("GPIO INIT ERR\n");
+
+    rv = spi_init();
+    if (rv) printf("SPI INIT ERR\n");
+
+    while (1);
+}