stmhal: Add basic CAN bus support.

5 files changed, 509 insertions, 0 deletions

diff --git a/stmhal/Makefile b/stmhal/Makefile
index 21e09666b..8ff2d9294 100644
--- a/stmhal/Makefile
+++ b/stmhal/Makefile
@@ -90,6 +90,7 @@ SRC_C = \
 	i2c.c \
 	spi.c \
 	uart.c \
+	can.c \
 	usb.c \
 	printf.c \
 	gccollect.c \
@@ -132,6 +133,7 @@ SRC_HAL = $(addprefix $(HAL_DIR)/src/,\
 	stm32f4xx_hal.c \
 	stm32f4xx_hal_adc.c \
 	stm32f4xx_hal_adc_ex.c \
+	stm32f4xx_hal_can.c \
 	stm32f4xx_hal_cortex.c \
 	stm32f4xx_hal_dac.c \
 	stm32f4xx_hal_dac_ex.c \
diff --git a/stmhal/can.c b/stmhal/can.c
new file mode 100644
index 000000000..82324a638
--- /dev/null
+++ b/stmhal/can.c
@@ -0,0 +1,453 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+#include <errno.h>
+
+#include "stm32f4xx_hal.h"
+
+#include "mpconfig.h"
+#include "nlr.h"
+#include "misc.h"
+#include "qstr.h"
+#include "obj.h"
+#include "objtuple.h"
+#include "runtime.h"
+#include "bufhelper.h"
+#include "can.h"
+#include "pybioctl.h"
+
+/// \moduleref pyb
+/// \class CAN - controller area network communication bus
+///
+/// CAN implements the standard CAN communications protocol.  At
+/// the physical level it consists of 2 lines: RX and TX.  Note that
+/// to connect the pyboard to a CAN bus you must use a CAN transceiver
+/// to convert the CAN logic signals from the pyboard to the correct
+/// voltage levels on the bus.
+///
+/// Note that this driver does not yet support filter configuration
+/// (it defaults to a single filter that lets through all messages),
+/// or bus timing configuration (except for setting the prescaler).
+///
+/// Example usage (works without anything connected):
+///
+///     from pyb import CAN
+///     can = pyb.CAN(1, pyb.CAN.LOOPBACK)
+///     can.send('message!', 123)   # send message to id 123
+///     can.recv(0)                 # receive message on FIFO 0
+
+typedef struct _pyb_can_obj_t {
+    mp_obj_base_t base;
+    mp_uint_t can_id : 8;
+    bool is_enabled : 1;
+    CAN_HandleTypeDef can;
+} pyb_can_obj_t;
+
+// assumes Init parameters have been set up correctly
+STATIC bool can_init(pyb_can_obj_t *can_obj) {
+    CAN_TypeDef *CANx = NULL;
+
+    uint32_t GPIO_Pin = 0;
+    uint8_t  GPIO_AF_CANx = 0;
+    GPIO_TypeDef* GPIO_Port = NULL;
+
+    switch (can_obj->can_id) {
+        // CAN1 is on RX,TX = Y3,Y4 = PB9,PB9
+        case PYB_CAN_1:
+            CANx = CAN1;
+            GPIO_AF_CANx = GPIO_AF9_CAN1;
+            GPIO_Port = GPIOB;
+            GPIO_Pin = GPIO_PIN_8 | GPIO_PIN_9;
+            __CAN1_CLK_ENABLE();
+            break;
+
+        // CAN2 is on RX,TX = Y5,Y6 = PB12,PB13
+        case PYB_CAN_2:
+            CANx = CAN2;
+            GPIO_AF_CANx = GPIO_AF9_CAN2;
+            GPIO_Port = GPIOB;
+            GPIO_Pin = GPIO_PIN_12 | GPIO_PIN_13;
+            __CAN1_CLK_ENABLE(); // CAN2 is a "slave" and needs CAN1 enabled as well
+            __CAN2_CLK_ENABLE();
+            break;
+
+        default:
+            return false;
+    }
+
+    // init GPIO
+    GPIO_InitTypeDef GPIO_InitStructure;
+    GPIO_InitStructure.Pin = GPIO_Pin;
+    GPIO_InitStructure.Speed = GPIO_SPEED_HIGH;
+    GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
+    GPIO_InitStructure.Pull = GPIO_PULLUP;
+    GPIO_InitStructure.Alternate = GPIO_AF_CANx;
+    HAL_GPIO_Init(GPIO_Port, &GPIO_InitStructure);
+
+    // init CANx
+    can_obj->can.Instance = CANx;
+    HAL_CAN_Init(&can_obj->can);
+
+    can_obj->is_enabled = true;
+
+    return true;
+}
+
+STATIC void can_deinit(pyb_can_obj_t *can_obj) {
+    can_obj->is_enabled = false;
+    CAN_HandleTypeDef *can = &can_obj->can;
+    HAL_CAN_DeInit(can);
+    if (can->Instance == CAN1) {
+        __CAN1_FORCE_RESET();
+        __CAN1_RELEASE_RESET();
+        __CAN1_CLK_DISABLE();
+    } else if (can->Instance == CAN2) {
+        __CAN2_FORCE_RESET();
+        __CAN2_RELEASE_RESET();
+        __CAN2_CLK_DISABLE();
+    }
+}
+
+/******************************************************************************/
+// Micro Python bindings
+
+STATIC void pyb_can_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
+    pyb_can_obj_t *self = self_in;
+    if (!self->is_enabled) {
+        print(env, "CAN(%u)", self->can_id);
+    } else {
+        print(env, "CAN(%u, ", self->can_id);
+        qstr mode;
+        switch (self->can.Init.Mode) {
+            case CAN_MODE_NORMAL: mode = MP_QSTR_NORMAL; break;
+            case CAN_MODE_LOOPBACK: mode = MP_QSTR_LOOPBACK; break;
+            case CAN_MODE_SILENT: mode = MP_QSTR_SILENT; break;
+            case CAN_MODE_SILENT_LOOPBACK: default: mode = MP_QSTR_SILENT_LOOPBACK; break;
+        }
+        print(env, "%s)", qstr_str(mode));
+    }
+}
+
+/// \method init(mode, prescaler=100, *, sjw=1, bs1=6, bs2=8)
+///
+/// Initialise the CAN bus with the given parameters:
+///
+///   - `mode` is one of:  NORMAL, LOOPBACK, SILENT, SILENT_LOOPBACK
+STATIC mp_obj_t pyb_can_init_helper(pyb_can_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_mode,         MP_ARG_REQUIRED | MP_ARG_INT,   {.u_int = CAN_MODE_NORMAL} },
+        { MP_QSTR_prescaler,    MP_ARG_INT,                     {.u_int = 100} },
+        /*
+        { MP_QSTR_sjw,          MP_ARG_KW_ONLY | MP_ARG_INT,    {.u_int = 1} },
+        { MP_QSTR_bs1,          MP_ARG_KW_ONLY | MP_ARG_INT,    {.u_int = 6} },
+        { MP_QSTR_bs2,          MP_ARG_KW_ONLY | MP_ARG_INT,    {.u_int = 8} },
+        */
+    };
+
+    // parse args
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    // set the CAN configuration values
+    memset(&self->can, 0, sizeof(self->can));
+    CAN_InitTypeDef *init = &self->can.Init;
+    init->Mode = args[0].u_int << 4; // shift-left so modes fit in a small-int
+    init->Prescaler = args[1].u_int;
+    init->SJW = CAN_SJW_1TQ; // TODO set from args
+    init->BS1 = CAN_BS1_6TQ; // TODO set from args
+    init->BS2 = CAN_BS2_8TQ; // TODO set from args
+    init->TTCM = DISABLE;
+    init->ABOM = DISABLE;
+    init->AWUM = DISABLE;
+    init->NART = DISABLE;
+    init->RFLM = DISABLE;
+    init->TXFP = DISABLE;
+
+    // init CAN (if it fails, it's because the port doesn't exist)
+    if (!can_init(self)) {
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "CAN port %d does not exist", self->can_id));
+    }
+
+    // set CAN filter to accept everything
+    CAN_FilterConfTypeDef filter;
+    filter.FilterIdHigh = 0;
+    filter.FilterIdLow = 0;
+    filter.FilterMaskIdHigh = 0;
+    filter.FilterMaskIdLow = 0;
+    filter.FilterFIFOAssignment = CAN_FILTER_FIFO0;
+    filter.FilterNumber = 0; // 0-27
+    filter.FilterMode = CAN_FILTERMODE_IDMASK;
+    filter.FilterScale = CAN_FILTERSCALE_32BIT;
+    filter.FilterActivation = ENABLE;
+    filter.BankNumber = 0; // what's this for?
+    HAL_CAN_ConfigFilter(&self->can, &filter);
+
+    return mp_const_none;
+}
+
+/// \classmethod \constructor(bus, ...)
+///
+/// Construct a CAN object on the given bus.  `bus` can be 1-2, or 'YA' or 'YB'.
+/// With no additional parameters, the CAN object is created but not
+/// initialised (it has the settings from the last initialisation of
+/// the bus, if any).  If extra arguments are given, the bus is initialised.
+/// See `init` for parameters of initialisation.
+///
+/// The physical pins of the CAN busses are:
+///
+///   - `CAN(1)` is on `YA`: `(RX, TX) = (Y3, Y4) = (PB8, PB9)`
+///   - `CAN(2)` is on `YB`: `(RX, TX) = (Y5, Y6) = (PB12, PB13)`
+STATIC mp_obj_t pyb_can_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+    // check arguments
+    mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
+
+    // create object
+    pyb_can_obj_t *o = m_new_obj(pyb_can_obj_t);
+    o->base.type = &pyb_can_type;
+    o->is_enabled = false;
+
+    // work out port
+    o->can_id = 0;
+    if (MP_OBJ_IS_STR(args[0])) {
+        const char *port = mp_obj_str_get_str(args[0]);
+        if (0) {
+        #if defined(PYBV10)
+        } else if (strcmp(port, "YA") == 0) {
+            o->can_id = PYB_CAN_YA;
+        } else if (strcmp(port, "YB") == 0) {
+            o->can_id = PYB_CAN_YB;
+        #endif
+        } else {
+            nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "CAN port %s does not exist", port));
+        }
+    } else {
+        o->can_id = mp_obj_get_int(args[0]);
+    }
+
+    if (n_args > 1 || n_kw > 0) {
+        // start the peripheral
+        mp_map_t kw_args;
+        mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
+        pyb_can_init_helper(o, n_args - 1, args + 1, &kw_args);
+    }
+
+    return o;
+}
+
+STATIC mp_obj_t pyb_can_init(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    return pyb_can_init_helper(args[0], n_args - 1, args + 1, kw_args);
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_can_init_obj, 1, pyb_can_init);
+
+/// \method deinit()
+/// Turn off the CAN bus.
+STATIC mp_obj_t pyb_can_deinit(mp_obj_t self_in) {
+    pyb_can_obj_t *self = self_in;
+    can_deinit(self);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_can_deinit_obj, pyb_can_deinit);
+
+/// \method any(fifo)
+/// Return `True` if any message waiting on the FIFO, else `False`.
+STATIC mp_obj_t pyb_can_any(mp_obj_t self_in, mp_obj_t fifo_in) {
+    pyb_can_obj_t *self = self_in;
+    mp_int_t fifo = mp_obj_get_int(fifo_in);
+    if (fifo == 0) {
+        if (__HAL_CAN_MSG_PENDING(&self->can, CAN_FIFO0) != 0) {
+            return mp_const_true;
+        }
+    } else {
+        if (__HAL_CAN_MSG_PENDING(&self->can, CAN_FIFO1) != 0) {
+            return mp_const_true;
+        }
+    }
+    return mp_const_false;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_can_any_obj, pyb_can_any);
+
+/// \method send(send, addr, *, timeout=5000)
+/// Send a message on the bus:
+///
+///   - `send` is the data to send (an integer to send, or a buffer object).
+///   - `addr` is the address to send to
+///   - `timeout` is the timeout in milliseconds to wait for the send.
+///
+/// Return value: `None`.
+STATIC mp_obj_t pyb_can_send(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_send,    MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
+        { MP_QSTR_addr,    MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 5000} },
+    };
+
+    // parse args
+    pyb_can_obj_t *self = pos_args[0];
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    // get the buffer to send from
+    mp_buffer_info_t bufinfo;
+    uint8_t data[1];
+    pyb_buf_get_for_send(args[0].u_obj, &bufinfo, data);
+    // TODO check bufinfo.len <= 8
+
+    // send the data
+    CanTxMsgTypeDef tx_msg;
+    tx_msg.StdId = args[1].u_int & 0x7ff;
+    tx_msg.ExtId = 0; // TODO support extended ids
+    tx_msg.IDE = CAN_ID_STD;
+    tx_msg.RTR = CAN_RTR_DATA;
+    tx_msg.DLC = bufinfo.len;
+    for (mp_uint_t i = 0; i < bufinfo.len; i++) {
+        tx_msg.Data[i] = ((byte*)bufinfo.buf)[i]; // Data is uint32_t but holds only 1 byte
+    }
+    self->can.pTxMsg = &tx_msg;
+    HAL_StatusTypeDef status = HAL_CAN_Transmit(&self->can, args[2].u_int);
+
+    if (status != HAL_OK) {
+        // TODO really need a HardwareError object, or something
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_CAN_Transmit failed with code %d", status));
+    }
+
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_can_send_obj, 1, pyb_can_send);
+
+/// \method recv(fifo, *, timeout=5000)
+///
+/// Receive data on the bus:
+///
+///   - `fifo` is an integer, which is the FIFO to receive on
+///   - `timeout` is the timeout in milliseconds to wait for the receive.
+///
+/// Return value: buffer of data bytes.
+STATIC mp_obj_t pyb_can_recv(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_fifo,    MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 5000} },
+    };
+
+    // parse args
+    pyb_can_obj_t *self = pos_args[0];
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    // receive the data
+    CanRxMsgTypeDef rx_msg;
+    self->can.pRxMsg = &rx_msg;
+    HAL_StatusTypeDef status = HAL_CAN_Receive(&self->can, args[0].u_int, args[1].u_int);
+
+    if (status != HAL_OK) {
+        // TODO really need a HardwareError object, or something
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_CAN_Receive failed with code %d", status));
+    }
+
+    // return the received data
+    // TODO use a namedtuple (when namedtuple types can be stored in ROM)
+    mp_obj_tuple_t *tuple = mp_obj_new_tuple(4, NULL);
+    if (rx_msg.IDE == CAN_ID_STD) {
+        tuple->items[0] = MP_OBJ_NEW_SMALL_INT(rx_msg.StdId);
+    } else {
+        tuple->items[0] = MP_OBJ_NEW_SMALL_INT(rx_msg.ExtId);
+    }
+    tuple->items[1] = MP_OBJ_NEW_SMALL_INT(rx_msg.RTR);
+    tuple->items[2] = MP_OBJ_NEW_SMALL_INT(rx_msg.FMI);
+    byte *data;
+    tuple->items[3] = mp_obj_str_builder_start(&mp_type_bytes, rx_msg.DLC, &data);
+    for (mp_uint_t i = 0; i < rx_msg.DLC; i++) {
+        data[i] = rx_msg.Data[i]; // Data is uint32_t but holds only 1 byte
+    }
+    tuple->items[3] = mp_obj_str_builder_end(tuple->items[3]);
+    return tuple;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_can_recv_obj, 1, pyb_can_recv);
+
+STATIC const mp_map_elem_t pyb_can_locals_dict_table[] = {
+    // instance methods
+    { MP_OBJ_NEW_QSTR(MP_QSTR_init), (mp_obj_t)&pyb_can_init_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_deinit), (mp_obj_t)&pyb_can_deinit_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_any), (mp_obj_t)&pyb_can_any_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_send), (mp_obj_t)&pyb_can_send_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_recv), (mp_obj_t)&pyb_can_recv_obj },
+
+    // class constants
+    /// \constant MASTER - for initialising the bus to master mode
+    /// \constant SLAVE - for initialising the bus to slave mode
+    /// \constant MSB - set the first bit to MSB
+    /// \constant LSB - set the first bit to LSB
+    // Note: we use the ST constants >> 4 so they fit in a small-int.  The
+    // right-shift is undone when the constants are used in the init function.
+    { MP_OBJ_NEW_QSTR(MP_QSTR_NORMAL), MP_OBJ_NEW_SMALL_INT(CAN_MODE_NORMAL >> 4) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_LOOPBACK), MP_OBJ_NEW_SMALL_INT(CAN_MODE_LOOPBACK >> 4) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_SILENT), MP_OBJ_NEW_SMALL_INT(CAN_MODE_SILENT >> 4) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_SILENT_LOOPBACK), MP_OBJ_NEW_SMALL_INT(CAN_MODE_SILENT_LOOPBACK >> 4) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(pyb_can_locals_dict, pyb_can_locals_dict_table);
+
+mp_uint_t can_ioctl(mp_obj_t self_in, mp_uint_t request, int *errcode, ...) {
+    pyb_can_obj_t *self = self_in;
+    va_list vargs;
+    va_start(vargs, errcode);
+    mp_uint_t ret;
+    if (request == MP_IOCTL_POLL) {
+        mp_uint_t flags = va_arg(vargs, mp_uint_t);
+        ret = 0;
+        if ((flags & MP_IOCTL_POLL_RD)
+            && ((__HAL_CAN_MSG_PENDING(&self->can, CAN_FIFO0) != 0)
+                || (__HAL_CAN_MSG_PENDING(&self->can, CAN_FIFO1) != 0))) {
+            ret |= MP_IOCTL_POLL_RD;
+        }
+        if ((flags & MP_IOCTL_POLL_WR) && (self->can.Instance->TSR & CAN_TSR_TME)) {
+            ret |= MP_IOCTL_POLL_WR;
+        }
+    } else {
+        *errcode = EINVAL;
+        ret = -1;
+    }
+    va_end(vargs);
+    return ret;
+}
+
+STATIC const mp_stream_p_t can_stream_p = {
+    //.read = can_read, // is read sensible for CAN?
+    //.write = can_write, // is write sensible for CAN?
+    .ioctl = can_ioctl,
+    .is_text = false,
+};
+
+const mp_obj_type_t pyb_can_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_CAN,
+    .print = pyb_can_print,
+    .make_new = pyb_can_make_new,
+    .stream_p = &can_stream_p,
+    .locals_dict = (mp_obj_t)&pyb_can_locals_dict,
+};
diff --git a/stmhal/can.h b/stmhal/can.h
new file mode 100644
index 000000000..07b654d2e
--- /dev/null
+++ b/stmhal/can.h
@@ -0,0 +1,36 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#define PYB_CAN_1 (1)
+#define PYB_CAN_2 (2)
+
+// aliases for pyboard
+#if defined(PYBV10)
+#define PYB_CAN_YA PYB_CAN_1 // CAN1 on RX,TX = Y3,Y4 = PB8,PB9
+#define PYB_CAN_YB PYB_CAN_2 // CAN2 on RX,TX = Y5,Y6 = PB12,PB13
+#endif
+
+extern const mp_obj_type_t pyb_can_type;
diff --git a/stmhal/modpyb.c b/stmhal/modpyb.c
index 7f39098ca..ae2a1d7c4 100644
--- a/stmhal/modpyb.c
+++ b/stmhal/modpyb.c
@@ -49,6 +49,7 @@
 #include "i2c.h"
 #include "spi.h"
 #include "uart.h"
+#include "can.h"
 #include "adc.h"
 #include "storage.h"
 #include "sdcard.h"
@@ -436,6 +437,7 @@ STATIC const mp_map_elem_t pyb_module_globals_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_I2C), (mp_obj_t)&pyb_i2c_type },
     { MP_OBJ_NEW_QSTR(MP_QSTR_SPI), (mp_obj_t)&pyb_spi_type },
     { MP_OBJ_NEW_QSTR(MP_QSTR_UART), (mp_obj_t)&pyb_uart_type },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_CAN), (mp_obj_t)&pyb_can_type },
 
     { MP_OBJ_NEW_QSTR(MP_QSTR_ADC), (mp_obj_t)&pyb_adc_type },
     { MP_OBJ_NEW_QSTR(MP_QSTR_ADCAll), (mp_obj_t)&pyb_adc_all_type },
diff --git a/stmhal/qstrdefsport.h b/stmhal/qstrdefsport.h
index d0d8c113b..fd939d25d 100644
--- a/stmhal/qstrdefsport.h
+++ b/stmhal/qstrdefsport.h
@@ -144,6 +144,22 @@ Q(all)
 Q(send)
 Q(recv)
 
+// for CAN class
+Q(CAN)
+Q(prescaler)
+Q(init)
+Q(deinit)
+Q(all)
+Q(send)
+Q(recv)
+Q(addr)
+Q(fifo)
+Q(timeout)
+Q(NORMAL)
+Q(LOOPBACK)
+Q(SILENT)
+Q(SILENT_LOOPBACK)
+
 // for Timer class
 Q(Timer)
 Q(init)