Merge pull request commaai#34 from diamondman/feature/ELM327_support

Feature/elm327 support

board/drivers/can.h

@@ -53,6 +53,12 @@ int can_push(can_ring *q, CAN_FIFOMailBox_TypeDef *elem) {
   return ret;
 }
 
+void can_clear(can_ring *q) {
+  enter_critical_section();
+  q->w_ptr = 0;
+  q->r_ptr = 0;
+  exit_critical_section();
+}
 
 // assign CAN numbering
 // bus num: Can bus number on ODB connector. Sent to/from USB
@@ -393,4 +399,3 @@ void can_send(CAN_FIFOMailBox_TypeDef *to_push, uint8_t bus_number) {
 void can_set_forwarding(int from, int to) {
   can_forwarding[from] = to;
 }
-

board/drivers/uart.h

@@ -126,6 +126,15 @@ int putc(uart_ring *q, char elem) {
   return ret;
 }
 
+void clear_uart_buff(uart_ring *q) {
+  enter_critical_section();
+  q->w_ptr_tx = 0;
+  q->r_ptr_tx = 0;
+  q->w_ptr_rx = 0;
+  q->r_ptr_rx = 0;
+  exit_critical_section();
+}
+
 // ***************************** start UART code *****************************
 
 #define __DIV(_PCLK_, _BAUD_)                        (((_PCLK_)*25)/(4*(_BAUD_)))
@@ -146,7 +155,7 @@ void uart_init(USART_TypeDef *u, int baud) {
   // enable uart and tx+rx mode
   u->CR1 = USART_CR1_UE;
   uart_set_baud(u, baud);
-  
+
   u->CR1 |= USART_CR1_TE | USART_CR1_RE;
   //u->CR2 = USART_CR2_STOP_0 | USART_CR2_STOP_1;
   //u->CR2 = USART_CR2_STOP_0;
@@ -213,4 +222,3 @@ void hexdump(const void *a, int l) {
   }
   puts("\n");
 }
-

board/main.c

@@ -117,12 +117,11 @@ int usb_cb_ep1_in(uint8_t *usbdata, int len, int hardwired) {
 
 // send on serial, first byte to select the ring
 void usb_cb_ep2_out(uint8_t *usbdata, int len, int hardwired) {
-  int i;
   if (len == 0) return;
   uart_ring *ur = get_ring_by_number(usbdata[0]);
   if (!ur) return;
   if ((usbdata[0] < 2) || safety_tx_lin_hook(usbdata[0]-2, usbdata+1, len-1)) {
-    for (i = 1; i < len; i++) while (!putc(ur, usbdata[i]));
+    for (int i = 1; i < len; i++) while (!putc(ur, usbdata[i]));
   }
 }
 
@@ -251,7 +250,8 @@ int usb_cb_control_msg(USB_Setup_TypeDef *setup, uint8_t *resp, int hardwired) {
     case 0xdc:
       // this is the only way to leave silent mode
       // and it's blocked over WiFi
-      if (hardwired) {
+      // Allow ELM security mode to be set over wifi.
+      if (hardwired || setup->b.wValue.w == SAFETY_ELM327) {
         safety_set_mode(setup->b.wValue.w);
         can_silent = (setup->b.wValue.w == SAFETY_NOOUTPUT);
         can_init_all();
@@ -358,6 +358,26 @@ int usb_cb_control_msg(USB_Setup_TypeDef *setup, uint8_t *resp, int hardwired) {
 
       delay(140 * 9000);
       break;
+    // **** 0xf1: Clear CAN ring buffer.
+    case 0xf1:
+      if (setup->b.wValue.w == 0xFFFF) {
+        puts("Clearing CAN Rx queue\n");
+        can_clear(&can_rx_q);
+      } else if (setup->b.wValue.w < BUS_MAX) {
+        puts("Clearing CAN Tx queue\n");
+        can_clear(can_queues[setup->b.wValue.w]);
+      }
+      break;
+    // **** 0xf2: Clear UART ring buffer.
+    case 0xf2:
+      {
+        uart_ring * rb = get_ring_by_number(setup->b.wValue.w);
+        if (rb) {
+          puts("Clearing UART queue.\n");
+          clear_uart_buff(rb);
+        }
+        break;
+      }
     default:
       puts("NO HANDLER ");
       puth(setup->b.bRequest);
@@ -508,4 +528,3 @@ int main() {
 
   return 0;
 }
-

board/safety.h

@@ -20,6 +20,7 @@ int controls_allowed = 0;
 // Include the actual safety policies.
 #include "safety/safety_defaults.h"
 #include "safety/safety_honda.h"
+#include "safety/safety_elm327.h"
 
 const safety_hooks *current_hooks = &nooutput_hooks;
 
@@ -43,11 +44,13 @@ typedef struct {
 #define SAFETY_NOOUTPUT 0
 #define SAFETY_HONDA 1
 #define SAFETY_ALLOUTPUT 0x1337
+#define SAFETY_ELM327 0xE327
 
 const safety_hook_config safety_hook_registry[] = {
   {SAFETY_NOOUTPUT, &nooutput_hooks},
   {SAFETY_HONDA, &honda_hooks},
   {SAFETY_ALLOUTPUT, &alloutput_hooks},
+  {SAFETY_ELM327, &elm327_hooks},
 };
 
 #define HOOK_CONFIG_COUNT (sizeof(safety_hook_registry)/sizeof(safety_hook_config))
@@ -56,10 +59,9 @@ int safety_set_mode(uint16_t mode){
   for (int i = 0; i < HOOK_CONFIG_COUNT; i++) {
     if (safety_hook_registry[i].id == mode) {
       current_hooks = safety_hook_registry[i].hooks;
-      current_hooks->init();
+      if(current_hooks->init) current_hooks->init();
       return 0;
     }
   }
   return -1;
 }
-

board/safety/safety_elm327.h

@@ -0,0 +1,35 @@
+static void elm327_rx_hook(CAN_FIFOMailBox_TypeDef *to_push) {}
+
+static int elm327_tx_hook(CAN_FIFOMailBox_TypeDef *to_send) {
+  //All ELM traffic must appear on CAN0
+  if(((to_send->RDTR >> 4) & 0xf) != 0) return 0;
+  //All ISO 15765-4 messages must be 8 bytes long
+  if((to_send->RDTR & 0xf) != 8) return 0;
+
+  if(to_send->RIR & 4){
+    uint32_t addr = to_send->RIR >> 3;
+    //Check valid 29 bit send addresses for ISO 15765-4
+    if(!(addr == 0x18DB33F1 || (addr & 0x1FFF00FF) == 0x18DA00F1)) return 0;
+  } else {
+    uint32_t addr = to_send->RIR >> 21;
+    //Check valid 11 bit send addresses for ISO 15765-4
+    if(!(addr == 0x7DF || (addr & 0x7F8) == 0x7E0)) return 0;
+  }
+
+  return true;
+}
+
+static int elm327_tx_lin_hook(int lin_num, uint8_t *data, int len) {
+  if(lin_num != 0) return false; //Only operate on LIN 0, aka serial 2
+  if(len < 5 || len > 11) return false; //Valid KWP size
+  if(!((data[0] & 0xF8) == 0xC0 && (data[0] & 0x07) > 0 &&
+       data[1] == 0x33 && data[2] == 0xF1)) return false; //Bad msg
+  return true;
+}
+
+const safety_hooks elm327_hooks = {
+  .init = NULL,
+  .rx = elm327_rx_hook,
+  .tx = elm327_tx_hook,
+  .tx_lin = elm327_tx_lin_hook,
+};

boardesp/ELM327.md

@@ -0,0 +1,101 @@
+ELM327 support for panda
+======
+The panda now has basic ELM327 support.
+
+### What is ELM327?
+
+ELM327 is a command protocol for interfacing with cars using an OBD-II
+port to read [list](standard vehicle diagnostic codes). ELM327
+originally referred to a line of programmable microcontrollers that
+implemented the ELM327 command protocol, and are still being
+developed.
+
+ELM327 devices present a shell and commands are sent via a UART. The
+official ELM327 chips only support raw UART communication, but most
+devices built with the ELM327 devices (official or clones) expose the
+UART in a more modern way (Wifi, USB, etc).
+
+Mechanics use ELM to diagnose vehicles, and reset fault codes in the
+car's computer after fixing the issue (turning off the dreaded check
+engine light). Car owners can use ELM devices to perform the same
+diagnostics in their garage using either a raw terminal to send
+commands to the ELM device directly, or using a GUI (like one of
+several popular smart phone apps) to translate the OBD error codes
+into readable messages. These GUIs also often allow monitoring of the
+performance of the car's speed, engine rpm, etc.
+
+The panda natively supports sending all the important OBD diagnostic
+messages, but ELM327 support removes the need for the user to manually
+craft CAN or LIN packets using the native panda API, and grants
+compatibility with many existing tools.
+
+[Wikipedia](https://en.wikipedia.org/wiki/ELM327) can provide
+additional information.
+
+### OBD Protocols?
+
+While the commands that the OBD standard describe are in fact
+standard, there are several different protocols that those messages
+can be sent and received with. All cars after 1991 support one of
+these protocols. Which one depends on the car's year and country, as
+legal requirements change over the years.
+
+The panda supports the most popular/modern of these protocols, and all
+but two can be added as needed. Below is a chart of the OBD-II
+protocols supported by the panda.
+
+| Protocol | Support Status |
+| --- | --- |
+| SAE J1850 PWM (41.6 kbit/s) | Never/Obsolete |
+| SAE J1850 VPW (10.4 kbit/s) | Never/Obsolete |
+| ISO 9141-2 (5 baud init, 10.4 kbit/s) | Unsupported |
+| ISO 14230-4 KWP (5 baud init, 10.4 kbit/s) | Unsupported |
+| ISO 14230-4 KWP (fast init, 10.4 kbit/s) | Supported |
+| ISO 15765-4 CAN (11 bit ID, 500 kbit/s) | Supported |
+| ISO 15765-4 CAN (29 bit ID, 500 kbit/s) | Supported |
+| ISO 15765-4 CAN (11 bit ID, 250 kbit/s) | Supported |
+| ISO 15765-4 CAN (29 bit ID, 250 kbit/s) | Supported |
+| SAE J1939 (250kbps) | Unsupported |
+
+### The Implementation
+
+The panda ELM327 implementation is not a full implementation of all
+the features of the official ELM327 microcontroller. Like most ELM327
+clones, the panda reports its ELM version as the unreleased version
+1.5, despite only implementing commands from protocol version 1.0.
+
+
+### Testing
+
+These tests require two pandas. One to be tested, and the second to
+simulate the vehicle.
+
+The panda used to simulate the vehicle must be plugged into a USB port
+of the testing computer.
+
+The computer running the tests must be connected to the panda being
+tested's wifi network.
+
+The following command will run the tests (nosetest should work fine
+instead of pytest if you still prefer using that). The CANSIMSERIAL
+environment variable will force the car simulator to use the correct
+panda as the simulator if multiple pandas are attached via usb to the
+host computer.
+
+```
+CANSIMSERIAL=car_sim_panda_serial pytest tests/automated/elm_wifi.py
+```
+
+A single test can be run by putting the test name after the file name
+and two colons, like so:
+
+```
+CANSIMSERIAL=car_sim_panda_serial pytest tests/automated/elm_wifi.py::test_important_thing
+```
+
+For more detail, provide the -s (show output) and the -vv (very
+verbose) flags.
+
+```
+CANSIMSERIAL=car_sim_panda_serial pytest -s -vv tests/automated/elm_wifi.py
+```