Merge pull request #122 from commaai/gmbitbang

Gmbitbang

board/drivers/can.h

@@ -461,14 +461,21 @@ void CAN3_SCE_IRQHandler() { can_sce(CAN3); }
 
 #endif
 
+#include "canbitbang.h"
+
 void can_send(CAN_FIFOMailBox_TypeDef *to_push, uint8_t bus_number) {
   if (safety_tx_hook(to_push) && !can_autobaud_enabled[bus_number]) {
     if (bus_number < BUS_MAX) {
       // add CAN packet to send queue
       // bus number isn't passed through
       to_push->RDTR &= 0xF;
-      can_push(can_queues[bus_number], to_push);
-      process_can(CAN_NUM_FROM_BUS_NUM(bus_number));
+      if (bus_number == 3 && can_num_lookup[3] == 0xFF) {
+        // TODO: why uint8 bro? only int8?
+        bitbang_gmlan(to_push);
+      } else {
+        can_push(can_queues[bus_number], to_push);
+        process_can(CAN_NUM_FROM_BUS_NUM(bus_number));
+      }
     }
   }
 }

board/drivers/canbitbang.h

@@ -0,0 +1,156 @@
+#define MAX_BITS_CAN_PACKET (64+44+25)
+
+// returns out_len
+int do_bitstuff(char *out, char *in, int in_len) {
+  int last_bit = -1;
+  int bit_cnt = 0;
+  int j = 0;
+  for (int i = 0; i < in_len; i++) {
+    char bit = in[i];
+    out[j++] = bit;
+
+    // do the stuffing
+    if (bit == last_bit) {
+      bit_cnt++;
+      if (bit_cnt == 5) {
+        // 5 in a row the same, do stuff
+        last_bit = !bit;
+        out[j++] = last_bit;
+        bit_cnt = 1;
+      }
+    } else {
+      // this is a new bit
+      last_bit = bit;
+      bit_cnt = 1;
+    }
+  }
+  return j;
+}
+
+int append_crc(char *in, int in_len) {
+  int crc = 0;
+  for (int i = 0; i < in_len; i++) {
+    crc <<= 1;
+    if (in[i] ^ ((crc>>15)&1)) {
+      crc = crc ^ 0x4599;
+    }
+    crc &= 0x7fff;
+  }
+  for (int i = 14; i >= 0; i--) {
+    in[in_len++] = (crc>>i)&1;
+  }
+  return in_len;
+}
+
+int append_bits(char *in, int in_len, char *app, int app_len) {
+  for (int i = 0; i < app_len; i++) {
+    in[in_len++] = app[i];
+  }
+  return in_len;
+}
+
+int append_int(char *in, int in_len, int val, int val_len) {
+  for (int i = val_len-1; i >= 0; i--) {
+    in[in_len++] = (val&(1<<i)) != 0;
+  }
+  return in_len;
+}
+
+int get_bit_message(char *out, CAN_FIFOMailBox_TypeDef *to_bang) {
+  char pkt[MAX_BITS_CAN_PACKET];
+  char footer[] = {
+    1,  // CRC delimiter
+    1,  // ACK
+    1,  // ACK delimiter
+    1,1,1,1,1,1,1, // EOF
+    1,1,1, // IFS
+  };
+  #define SPEEED 30
+
+  int len = 0;
+
+  // test packet
+  int dlc_len = to_bang->RDTR & 0xF;
+  len = append_int(pkt, len, 0, 1);    // Start-of-frame
+  len = append_int(pkt, len, to_bang->RIR >> 21, 11);  // Identifier
+  len = append_int(pkt, len, 0, 3);    // RTR+IDE+reserved
+  len = append_int(pkt, len, dlc_len, 4);    // Data length code
+
+  // append data
+  for (int i = 0; i < dlc_len; i++) {
+    unsigned char dat = ((unsigned char *)(&(to_bang->RDLR)))[i];
+    len = append_int(pkt, len, dat, 8);
+  }
+
+  // append crc
+  len = append_crc(pkt, len);
+
+  // do bitstuffing
+  len = do_bitstuff(out, pkt, len);
+
+  // append footer
+  len = append_bits(out, len, footer, sizeof(footer));
+  return len;
+}
+
+// hardware stuff below this line
+
+#ifdef PANDA
+
+void set_bitbanged_gmlan(int val) {
+  if (val) {
+    GPIOB->ODR |= (1 << 13);
+  } else {
+    GPIOB->ODR &= ~(1 << 13);
+  }
+}
+
+void bitbang_gmlan(CAN_FIFOMailBox_TypeDef *to_bang) {
+  puts("called bitbang_gmlan\n");
+
+  char pkt_stuffed[MAX_BITS_CAN_PACKET];
+  int len = get_bit_message(pkt_stuffed, to_bang);
+
+  // actual bitbang loop
+  set_bitbanged_gmlan(1); // recessive
+  set_gpio_mode(GPIOB, 13, MODE_OUTPUT);
+  enter_critical_section();
+
+  // wait for bus silent for 7 frames
+  int silent_count = 0;
+  while (silent_count < 7) {
+    int read = get_gpio_input(GPIOB, 12);
+    silent_count++;
+    if (read == 0) {
+      silent_count = 0;
+    }
+    int lwait = TIM2->CNT;
+    while (get_ts_elapsed(TIM2->CNT, lwait) < SPEEED);
+  }
+
+  // send my message with optional failure
+  int last = 1;
+  int init = TIM2->CNT;
+  for (int i = 0; i < len; i++) {
+    while (get_ts_elapsed(TIM2->CNT, init) < (SPEEED*i));
+    int read = get_gpio_input(GPIOB, 12);
+    if ((read == 0 && last == 1) && i != (len-11)) {
+      puts("ERR: bus driven at ");
+      puth(i);
+      puts("\n");
+      goto fail;
+    }
+    set_bitbanged_gmlan(pkt_stuffed[i]);
+    last = pkt_stuffed[i];
+  }
+
+fail:
+  set_bitbanged_gmlan(1); // recessive
+  exit_critical_section();
+  set_gpio_mode(GPIOB, 13, MODE_INPUT);
+
+  puts("bitbang done\n");
+}
+
+#endif
+

tests/gmbitbang/rigol.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+import numpy as np
+import visa
+import matplotlib.pyplot as plt
+
+resources = visa.ResourceManager()
+print resources.list_resources()
+
+scope = resources.open_resource('USB0::0x1AB1::0x04CE::DS1ZA184652242::INSTR', timeout=2000, chunk_size=1024000)
+print(scope.query('*IDN?').strip())
+
+#voltscale = scope.ask_for_values(':CHAN1:SCAL?')[0]
+#voltoffset = scope.ask_for_values(":CHAN1:OFFS?")[0]
+
+#scope.write(":STOP")
+scope.write(":WAV:POIN:MODE RAW")
+scope.write(":WAV:DATA? CHAN1")[10:]
+rawdata = scope.read_raw()
+data = np.frombuffer(rawdata, 'B')
+print data.shape
+
+s1 = data[0:650]
+s2 = data[650:]
+s1i = np.argmax(s1 > 100)
+s2i = np.argmax(s2 > 100)
+s1 = s1[s1i:]
+s2 = s2[s2i:]
+
+plt.plot(s1)
+plt.plot(s2)
+plt.show()
+#data = (data - 130.0 - voltoffset/voltscale*25) / 25 * voltscale
+
+print data
+

tests/gmbitbang/test.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python
+import time
+from panda import Panda
+
+p1 = Panda('430026000951363338383037')
+p2 = Panda('380016000551363338383037')
+
+# this is a test, no safety
+p1.set_safety_mode(Panda.SAFETY_ALLOUTPUT)
+p2.set_safety_mode(Panda.SAFETY_ALLOUTPUT)
+
+# get versions
+print(p1.get_version())
+print(p2.get_version())
+
+# this sets bus 2 to actually be GMLAN
+p2.set_gmlan(bus=2)
+
+# send w bitbang then without
+while 1:
+  p1.set_gmlan(bus=None)
+  p1.can_send(123, "\x01\x02\x03\x04\x05\x06\x07\x08", bus=3)
+  p1.set_gmlan(bus=2)
+  p1.can_send(123, "\x01\x02\x03\x04\x05\x06\x07\x08", bus=3)
+  time.sleep(0.01)
+  print p2.can_recv()
+  exit(0)
+

tests/gmbitbang/test_packer.c

@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <stdint.h>
+
+typedef struct {
+  uint32_t RIR;  /*!< CAN receive FIFO mailbox identifier register */
+  uint32_t RDTR; /*!< CAN receive FIFO mailbox data length control and time stamp register */
+  uint32_t RDLR; /*!< CAN receive FIFO mailbox data low register */
+  uint32_t RDHR; /*!< CAN receive FIFO mailbox data high register */
+} CAN_FIFOMailBox_TypeDef;
+
+#include "../../board/drivers/canbitbang.h"
+
+int main() {
+  char out[300];
+  CAN_FIFOMailBox_TypeDef to_bang = {0};
+  to_bang.RIR = 20 << 21;
+  to_bang.RDTR = 1;
+  to_bang.RDLR = 1;
+
+  int len = get_bit_message(out, &to_bang);
+  printf("T:");
+  for (int i = 0; i < len; i++) {
+    printf("%d", out[i]);
+  }
+  printf("\n");
+  printf("R:0000010010100000100010000010011110111010100111111111111111");
+  printf("\n");
+  return 0;
+}
+
+
+