cc2500: optimize set channel and packet_size

BossHobby · Nov 17, 2022 · c16d52e · c16d52e
1 parent 471ee2d
commit c16d52e
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Showing 6 changed files with 62 additions and 39 deletions.
diff --git a/src/drivers/drv_spi_cc2500.c b/src/drivers/drv_spi_cc2500.c
@@ -124,6 +124,59 @@ static void cc2500_write_multi(uint8_t reg, uint8_t *data, uint8_t len) {
   spi_txn_continue_ex(&bus, true);
 }
 
+void cc2500_set_channel(uint8_t channel, uint8_t *cal_data) {
+  {
+    spi_txn_t *txn = spi_txn_init(&bus, NULL);
+    spi_txn_add_seg_const(txn, CC2500_SIDLE);
+    spi_txn_submit(txn);
+  }
+  {
+    spi_txn_t *txn = spi_txn_init(&bus, NULL);
+    spi_txn_add_seg_const(txn, CC2500_FSCAL3 | CC2500_WRITE_BURST);
+    spi_txn_add_seg(txn, NULL, cal_data, 3);
+    spi_txn_submit(txn);
+  }
+  {
+    spi_txn_t *txn = spi_txn_init(&bus, NULL);
+    spi_txn_add_seg_const(txn, CC2500_CHANNR | CC2500_WRITE_SINGLE);
+    spi_txn_add_seg_const(txn, channel);
+    spi_txn_submit(txn);
+  }
+  spi_txn_continue(&bus);
+}
+
+uint8_t cc2500_packet_size() {
+  if (cc2500_read_gdo0() == 0) {
+    return 0;
+  }
+
+  // there is a bug in the cc2500
+  // see p3 http:// www.ti.com/lit/er/swrz002e/swrz002e.pdf
+  // workaround: read len register very quickly twice:
+
+  // try this 10 times befor giving up:
+  for (uint8_t i = 0; i < 10; i++) {
+    uint8_t len1 = 0;
+    uint8_t len2 = 0;
+
+    {
+      spi_txn_t *txn = spi_txn_init(&bus, NULL);
+      spi_txn_add_seg_const(txn, CC2500_RXBYTES | CC2500_READ_SINGLE);
+      spi_txn_add_seg(txn, &len1, NULL, 1);
+      spi_txn_add_seg_const(txn, CC2500_RXBYTES | CC2500_READ_SINGLE);
+      spi_txn_add_seg(txn, &len2, NULL, 1);
+      spi_txn_submit_wait(&bus, txn);
+    }
+
+    // valid len found?
+    if (len1 == len2) {
+      return len1;
+    }
+  }
+
+  return 0;
+}
+
 uint8_t cc2500_read_fifo(uint8_t *result, uint8_t len) {
   return cc2500_read_multi(CC2500_FIFO | CC2500_READ_BURST, result, len);
 }

diff --git a/src/drivers/drv_spi_cc2500.h b/src/drivers/drv_spi_cc2500.h
@@ -105,6 +105,8 @@ void cc2500_write_reg(uint8_t reg, uint8_t data);
 uint8_t cc2500_read_fifo(uint8_t *result, uint8_t len);
 void cc2500_write_fifo(uint8_t *data, uint8_t len);
 uint8_t cc2500_read_gdo0();
+void cc2500_set_channel(uint8_t channel, uint8_t *cal_data);
+uint8_t cc2500_packet_size();
 
 void cc2500_enter_rxmode();
 void cc2500_enter_txmode();

diff --git a/src/rx/rx_frsky.c b/src/rx/rx_frsky.c
@@ -74,13 +74,7 @@ void set_address(uint8_t is_bind) {
 }
 
 static void set_channel(uint8_t channel) {
-  cc2500_strobe(CC2500_SIDLE);
-
-  cc2500_write_reg(CC2500_FSCAL3, cal_data[channel][0]);
-  cc2500_write_reg(CC2500_FSCAL2, cal_data[channel][1]);
-  cc2500_write_reg(CC2500_FSCAL1, cal_data[channel][2]);
-
-  cc2500_write_reg(CC2500_CHANNR, channel);
+  cc2500_set_channel(channel, cal_data[channel]);
 }
 
 uint8_t next_channel(uint8_t skip) {
@@ -101,31 +95,8 @@ uint8_t next_channel(uint8_t skip) {
   return channr;
 }
 
-uint8_t packet_size() {
-  if (cc2500_read_gdo0() == 0) {
-    return 0;
-  }
-
-  // there is a bug in the cc2500
-  // see p3 http:// www.ti.com/lit/er/swrz002e/swrz002e.pdf
-  // workaround: read len register very quickly twice:
-
-  // try this 10 times befor giving up:
-  for (uint8_t i = 0; i < 10; i++) {
-    uint8_t len1 = cc2500_read_reg(CC2500_RXBYTES | CC2500_READ_BURST) & 0x7F;
-    uint8_t len2 = cc2500_read_reg(CC2500_RXBYTES | CC2500_READ_BURST) & 0x7F;
-
-    // valid len found?
-    if (len1 == len2) {
-      return len1;
-    }
-  }
-
-  return 0;
-}
-
 static uint8_t read_packet() {
-  uint8_t len = packet_size();
+  uint8_t len = cc2500_packet_size();
   if (len == 0) {
     return 0;
   }

diff --git a/src/rx/rx_frsky_d16.c b/src/rx/rx_frsky_d16.c
@@ -103,7 +103,6 @@ void handle_overflows();
 void calibrate_channels();
 void set_address(uint8_t is_bind);
 uint8_t next_channel(uint8_t skip);
-uint8_t packet_size();
 
 static uint16_t frsky_d16_crc(const uint8_t *data, uint8_t len) {
   uint16_t crc = 0;
@@ -303,7 +302,7 @@ static uint8_t frsky_d16_handle_packet() {
     last_packet_received_time = time_micros();
     // fallthrough
   case FRSKY_STATE_DATA: {
-    uint8_t len = packet_size();
+    uint8_t len = cc2500_packet_size();
     if (frame_had_packet == 0 && len >= FRSKY_D16_PACKET_LENGTH) {
       cc2500_read_fifo(packet, FRSKY_D16_PACKET_LENGTH);
       frsky_d16_frame_header *header = (frsky_d16_frame_header *)packet;

diff --git a/src/rx/rx_frsky_d8.c b/src/rx/rx_frsky_d8.c
@@ -42,7 +42,6 @@ void handle_overflows();
 void calibrate_channels();
 void set_address(uint8_t is_bind);
 uint8_t next_channel(uint8_t skip);
-uint8_t packet_size();
 
 static void frsky_d8_set_rc_data() {
   uint16_t channels[FRSKY_D8_CHANNEL_COUNT];
@@ -201,7 +200,7 @@ static uint8_t frsky_d8_handle_packet() {
     last_packet_received_time = current_packet_received_time;
     // fallthrough
   case FRSKY_STATE_DATA: {
-    uint8_t len = packet_size();
+    uint8_t len = cc2500_packet_size();
     if (len >= 20) {
       cc2500_read_fifo(packet, 20);
       frsky_d8_frame *frame = (frsky_d8_frame *)packet;

diff --git a/src/rx/rx_frsky_redpine.c b/src/rx/rx_frsky_redpine.c
@@ -35,7 +35,6 @@ void handle_overflows();
 void calibrate_channels();
 void set_address(uint8_t is_bind);
 uint8_t next_channel(uint8_t skip);
-uint8_t packet_size();
 
 static void redpine_set_rc_data() {
   if (packet[REDPINE_CHANNEL_START] == 1 && packet[REDPINE_CHANNEL_START + 1] == 0) {
@@ -110,7 +109,9 @@ static uint8_t redpine_handle_packet() {
 
     // fallthrough
   case FRSKY_STATE_DATA: {
-    uint8_t len = packet_size();
+    handle_overflows();
+
+    uint8_t len = cc2500_packet_size();
     if (len == REDPINE_PACKET_SIZE_W_ADDONS) {
       cc2500_read_fifo(packet, len);
 
@@ -149,8 +150,6 @@ static uint8_t redpine_handle_packet() {
       cc2500_strobe(CC2500_SFRX);
     }
 
-    handle_overflows();
-
     if ((time_micros() - total_time) > 50 * max_sync_delay) {
       // out of sync with packets - do a complete resysnc
       quic_debugf("REDPINE: resync %u", (time_micros() - total_time));