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circuitpython/stmhal/i2c.c

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#include <stdio.h>
#include <string.h>
#include "stm32f4xx_hal.h"
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
#include "pin.h"
#include "genhdr/pins.h"
#include "bufhelper.h"
#include "i2c.h"
// Usage model:
//
// I2C objects are created attached to a specific bus. They can be initialised
// when created, or initialised later on:
//
// from pyb import I2C
//
// i2c = I2C(1) # create on bus 1
// i2c = I2C(1, I2C.MASTER) # create and init as a master
// i2c.deinit() # turn off the peripheral
// i2c.init(I2C.MASTER, baudrate=20000) # init as a master
// i2c.init(I2C.SLAVE, addr=0x42) # init as a slave with given address
//
// Printing the i2c object gives you information about its configuration.
//
// Basic methods for slave are send and recv:
//
// i2c.send('abc') # send 3 bytes
// i2c.send(0x42) # send a single byte, given by the number
// data = i2c.recv(3) # receive 3 bytes
//
// To receive inplace, first create a bytearray:
//
// data = bytearray(3) # create a buffer
// i2c.recv(data) # receive 3 bytes, writing them into data
//
// You can specify a timeout (in ms):
//
// i2c.send(b'123', timeout=2000) # timout after 2 seconds
//
// A master must specify the recipient's address:
//
// i2c.init(I2C.MASTER)
// i2c.send('123', 0x42) # send 3 bytes to slave with address 0x42
// i2c.send(b'456', addr=0x42) # keyword for address
//
// Master also has other methods:
//
// i2c.is_ready(0x42) # check if slave 0x42 is ready
// i2c.scan() # scan for slaves on the bus, returning
// # a list of valid addresses
// i2c.mem_read(3, 0x42, 2) # read 3 bytes from memory of slave 0x42,
// # starting at address 2 in the slave
// i2c.mem_write('abc', 0x42, 2, timeout=1000)
#define PYB_I2C_MASTER (0)
#define PYB_I2C_SLAVE (1)
#if MICROPY_HW_ENABLE_I2C1
I2C_HandleTypeDef I2CHandle1 = {.Instance = NULL};
#endif
I2C_HandleTypeDef I2CHandle2 = {.Instance = NULL};
void i2c_init0(void) {
// reset the I2C1 handles
#if MICROPY_HW_ENABLE_I2C1
memset(&I2CHandle1, 0, sizeof(I2C_HandleTypeDef));
I2CHandle1.Instance = I2C1;
#endif
memset(&I2CHandle2, 0, sizeof(I2C_HandleTypeDef));
I2CHandle2.Instance = I2C2;
}
void i2c_init(I2C_HandleTypeDef *i2c) {
// init the GPIO lines
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.Mode = GPIO_MODE_AF_OD;
GPIO_InitStructure.Speed = GPIO_SPEED_FAST;
GPIO_InitStructure.Pull = GPIO_NOPULL; // have external pull-up resistors on both lines
const pin_obj_t *pins[2];
if (0) {
#if MICROPY_HW_ENABLE_I2C1
} else if (i2c == &I2CHandle1) {
// X-skin: X9=PB6=SCL, X10=PB7=SDA
pins[0] = &pin_B6;
pins[1] = &pin_B7;
GPIO_InitStructure.Alternate = GPIO_AF4_I2C1;
// enable the I2C clock
__I2C1_CLK_ENABLE();
#endif
} else if (i2c == &I2CHandle2) {
// Y-skin: Y9=PB10=SCL, Y10=PB11=SDA
pins[0] = &pin_B10;
pins[1] = &pin_B11;
GPIO_InitStructure.Alternate = GPIO_AF4_I2C2;
// enable the I2C clock
__I2C2_CLK_ENABLE();
} else {
// I2C does not exist for this board (shouldn't get here, should be checked by caller)
return;
}
// init the GPIO lines
for (uint i = 0; i < 2; i++) {
GPIO_InitStructure.Pin = pins[i]->pin_mask;
HAL_GPIO_Init(pins[i]->gpio, &GPIO_InitStructure);
}
// init the I2C device
if (HAL_I2C_Init(i2c) != HAL_OK) {
// init error
// TODO should raise an exception, but this function is not necessarily going to be
// called via Python, so may not be properly wrapped in an NLR handler
printf("HardwareError: HAL_I2C_Init failed\n");
return;
}
}
void i2c_deinit(I2C_HandleTypeDef *i2c) {
HAL_I2C_DeInit(i2c);
if (0) {
#if MICROPY_HW_ENABLE_I2C1
} else if (i2c->Instance == I2C1) {
__I2C1_FORCE_RESET();
__I2C1_RELEASE_RESET();
__I2C1_CLK_DISABLE();
#endif
} else if (i2c->Instance == I2C2) {
__I2C2_FORCE_RESET();
__I2C2_RELEASE_RESET();
__I2C2_CLK_DISABLE();
}
}
/******************************************************************************/
/* Micro Python bindings */
typedef struct _pyb_i2c_obj_t {
mp_obj_base_t base;
I2C_HandleTypeDef *i2c;
} pyb_i2c_obj_t;
STATIC inline bool in_master_mode(pyb_i2c_obj_t *self) { return self->i2c->Init.OwnAddress1 == PYB_I2C_MASTER_ADDRESS; }
STATIC const pyb_i2c_obj_t pyb_i2c_obj[] = {
#if MICROPY_HW_ENABLE_I2C1
{{&pyb_i2c_type}, &I2CHandle1},
#else
{{&pyb_i2c_type}, NULL},
#endif
{{&pyb_i2c_type}, &I2CHandle2}
};
#define PYB_NUM_I2C (sizeof(pyb_i2c_obj) / sizeof(pyb_i2c_obj[0]))
STATIC void pyb_i2c_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
pyb_i2c_obj_t *self = self_in;
uint i2c_num;
if (self->i2c->Instance == I2C1) { i2c_num = 1; }
else { i2c_num = 2; }
if (self->i2c->State == HAL_I2C_STATE_RESET) {
print(env, "I2C(%u)", i2c_num);
} else {
if (in_master_mode(self)) {
print(env, "I2C(%u, I2C.MASTER, baudrate=%u)", i2c_num, self->i2c->Init.ClockSpeed);
} else {
print(env, "I2C(%u, I2C.SLAVE, addr=0x%02x)", i2c_num, (self->i2c->Instance->OAR1 >> 1) & 0x7f);
}
}
}
STATIC const mp_arg_parse_t pyb_i2c_init_accepted_args[] = {
{ MP_QSTR_mode, MP_ARG_PARSE_REQUIRED | MP_ARG_PARSE_INT, {.u_int = 0} },
{ MP_QSTR_addr, MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT, {.u_int = 0x12} },
{ MP_QSTR_baudrate, MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT, {.u_int = 400000} },
{ MP_QSTR_gencall, MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_BOOL, {.u_bool = false} },
};
#define PYB_I2C_INIT_NUM_ARGS (sizeof(pyb_i2c_init_accepted_args) / sizeof(pyb_i2c_init_accepted_args[0]))
STATIC mp_obj_t pyb_i2c_init_helper(const pyb_i2c_obj_t *self, uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
// parse args
mp_arg_parse_val_t vals[PYB_I2C_INIT_NUM_ARGS];
mp_arg_parse_all(n_args, args, kw_args, PYB_I2C_INIT_NUM_ARGS, pyb_i2c_init_accepted_args, vals);
// set the I2C configuration values
I2C_InitTypeDef *init = &self->i2c->Init;
if (vals[0].u_int == PYB_I2C_MASTER) {
// use a special address to indicate we are a master
init->OwnAddress1 = PYB_I2C_MASTER_ADDRESS;
} else {
init->OwnAddress1 = (vals[1].u_int << 1) & 0xfe;
}
init->AddressingMode = I2C_ADDRESSINGMODE_7BIT;
init->ClockSpeed = MIN(vals[2].u_int, 400000);
init->DualAddressMode = I2C_DUALADDRESS_DISABLED;
init->DutyCycle = I2C_DUTYCYCLE_16_9;
init->GeneralCallMode = vals[3].u_bool ? I2C_GENERALCALL_ENABLED : I2C_GENERALCALL_DISABLED;
init->NoStretchMode = I2C_NOSTRETCH_DISABLED;
init->OwnAddress2 = 0xfe; // unused
// init the I2C bus
i2c_init(self->i2c);
return mp_const_none;
}
STATIC mp_obj_t pyb_i2c_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
// check arguments
mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
// get i2c number
machine_int_t i2c_id = mp_obj_get_int(args[0]) - 1;
// check i2c number
if (!(0 <= i2c_id && i2c_id < PYB_NUM_I2C && pyb_i2c_obj[i2c_id].i2c != NULL)) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "I2C bus %d does not exist", i2c_id + 1));
}
// get I2C object
const pyb_i2c_obj_t *i2c_obj = &pyb_i2c_obj[i2c_id];
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_i2c_init_helper(i2c_obj, n_args - 1, args + 1, &kw_args);
}
return (mp_obj_t)i2c_obj;
}
STATIC mp_obj_t pyb_i2c_init(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
return pyb_i2c_init_helper(args[0], n_args - 1, args + 1, kw_args);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_init_obj, 1, pyb_i2c_init);
STATIC mp_obj_t pyb_i2c_deinit(mp_obj_t self_in) {
pyb_i2c_obj_t *self = self_in;
i2c_deinit(self->i2c);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_i2c_deinit_obj, pyb_i2c_deinit);
// Check if an I2C device responds to the given address.
STATIC mp_obj_t pyb_i2c_is_ready(mp_obj_t self_in, mp_obj_t i2c_addr_o) {
pyb_i2c_obj_t *self = self_in;
if (!in_master_mode(self)) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "I2C must be a master"));
}
machine_uint_t i2c_addr = mp_obj_get_int(i2c_addr_o) << 1;
for (int i = 0; i < 10; i++) {
HAL_StatusTypeDef status = HAL_I2C_IsDeviceReady(self->i2c, i2c_addr, 10, 200);
if (status == HAL_OK) {
return mp_const_true;
}
}
return mp_const_false;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_i2c_is_ready_obj, pyb_i2c_is_ready);
// Scan all I2C addresses from 0x01 to 0x7f and return a list of those that respond.
STATIC mp_obj_t pyb_i2c_scan(mp_obj_t self_in) {
pyb_i2c_obj_t *self = self_in;
if (!in_master_mode(self)) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "I2C must be a master"));
}
mp_obj_t list = mp_obj_new_list(0, NULL);
for (uint addr = 1; addr <= 127; addr++) {
for (int i = 0; i < 10; i++) {
HAL_StatusTypeDef status = HAL_I2C_IsDeviceReady(self->i2c, addr << 1, 10, 200);
if (status == HAL_OK) {
mp_obj_list_append(list, mp_obj_new_int(addr));
break;
}
}
}
return list;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_i2c_scan_obj, pyb_i2c_scan);
STATIC const mp_arg_parse_t pyb_i2c_send_accepted_args[] = {
{ MP_QSTR_send, MP_ARG_PARSE_REQUIRED | MP_ARG_PARSE_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_addr, MP_ARG_PARSE_INT, {.u_int = PYB_I2C_MASTER_ADDRESS} },
{ MP_QSTR_timeout, MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT, {.u_int = 5000} },
};
#define PYB_I2C_SEND_NUM_ARGS (sizeof(pyb_i2c_send_accepted_args) / sizeof(pyb_i2c_send_accepted_args[0]))
STATIC mp_obj_t pyb_i2c_send(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
pyb_i2c_obj_t *self = args[0];
// parse args
mp_arg_parse_val_t vals[PYB_I2C_SEND_NUM_ARGS];
mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_SEND_NUM_ARGS, pyb_i2c_send_accepted_args, vals);
// get the buffer to send from
mp_buffer_info_t bufinfo;
uint8_t data[1];
pyb_buf_get_for_send(vals[0].u_obj, &bufinfo, data);
// send the data
HAL_StatusTypeDef status;
if (in_master_mode(self)) {
if (vals[1].u_int == PYB_I2C_MASTER_ADDRESS) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "addr argument required"));
}
machine_uint_t i2c_addr = vals[1].u_int << 1;
status = HAL_I2C_Master_Transmit(self->i2c, i2c_addr, bufinfo.buf, bufinfo.len, vals[2].u_int);
} else {
status = HAL_I2C_Slave_Transmit(self->i2c, bufinfo.buf, bufinfo.len, vals[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_I2C_xxx_Transmit failed with code %d", status));
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_send_obj, 1, pyb_i2c_send);
STATIC const mp_arg_parse_t pyb_i2c_recv_accepted_args[] = {
{ MP_QSTR_recv, MP_ARG_PARSE_REQUIRED | MP_ARG_PARSE_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_addr, MP_ARG_PARSE_INT, {.u_int = PYB_I2C_MASTER_ADDRESS} },
{ MP_QSTR_timeout, MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT, {.u_int = 5000} },
};
#define PYB_I2C_RECV_NUM_ARGS (sizeof(pyb_i2c_recv_accepted_args) / sizeof(pyb_i2c_recv_accepted_args[0]))
STATIC mp_obj_t pyb_i2c_recv(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
pyb_i2c_obj_t *self = args[0];
// parse args
mp_arg_parse_val_t vals[PYB_I2C_RECV_NUM_ARGS];
mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_RECV_NUM_ARGS, pyb_i2c_recv_accepted_args, vals);
// get the buffer to receive into
mp_buffer_info_t bufinfo;
mp_obj_t o_ret = pyb_buf_get_for_recv(vals[0].u_obj, &bufinfo);
// receive the data
HAL_StatusTypeDef status;
if (in_master_mode(self)) {
if (vals[1].u_int == PYB_I2C_MASTER_ADDRESS) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "addr argument required"));
}
machine_uint_t i2c_addr = vals[1].u_int << 1;
status = HAL_I2C_Master_Receive(self->i2c, i2c_addr, bufinfo.buf, bufinfo.len, vals[2].u_int);
} else {
status = HAL_I2C_Slave_Receive(self->i2c, bufinfo.buf, bufinfo.len, vals[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_I2C_xxx_Receive failed with code %d", status));
}
// return the received data
if (o_ret == MP_OBJ_NULL) {
return vals[0].u_obj;
} else {
return mp_obj_str_builder_end(o_ret);
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_recv_obj, 1, pyb_i2c_recv);
STATIC const mp_arg_parse_t pyb_i2c_mem_read_accepted_args[] = {
{ MP_QSTR_data, MP_ARG_PARSE_REQUIRED | MP_ARG_PARSE_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_addr, MP_ARG_PARSE_REQUIRED | MP_ARG_PARSE_INT, {.u_int = 0} },
{ MP_QSTR_memaddr, MP_ARG_PARSE_REQUIRED | MP_ARG_PARSE_INT, {.u_int = 0} },
{ MP_QSTR_timeout, MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT, {.u_int = 5000} },
};
#define PYB_I2C_MEM_READ_NUM_ARGS (sizeof(pyb_i2c_mem_read_accepted_args) / sizeof(pyb_i2c_mem_read_accepted_args[0]))
STATIC mp_obj_t pyb_i2c_mem_read(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
pyb_i2c_obj_t *self = args[0];
if (!in_master_mode(self)) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "I2C must be a master"));
}
// parse args
mp_arg_parse_val_t vals[PYB_I2C_MEM_READ_NUM_ARGS];
mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_MEM_READ_NUM_ARGS, pyb_i2c_mem_read_accepted_args, vals);
// get the buffer to read into
mp_buffer_info_t bufinfo;
mp_obj_t o_ret = pyb_buf_get_for_recv(vals[0].u_obj, &bufinfo);
// get the addresses
machine_uint_t i2c_addr = vals[1].u_int << 1;
machine_uint_t mem_addr = vals[2].u_int;
HAL_StatusTypeDef status = HAL_I2C_Mem_Read(self->i2c, i2c_addr, mem_addr, I2C_MEMADD_SIZE_8BIT, bufinfo.buf, bufinfo.len, vals[3].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_I2C_Mem_Read failed with code %d", status));
}
// return the read data
if (o_ret == MP_OBJ_NULL) {
return vals[0].u_obj;
} else {
return mp_obj_str_builder_end(o_ret);
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_mem_read_obj, 1, pyb_i2c_mem_read);
STATIC mp_obj_t pyb_i2c_mem_write(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
pyb_i2c_obj_t *self = args[0];
if (!in_master_mode(self)) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "I2C must be a master"));
}
// parse args (same as mem_read)
mp_arg_parse_val_t vals[PYB_I2C_MEM_READ_NUM_ARGS];
mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_MEM_READ_NUM_ARGS, pyb_i2c_mem_read_accepted_args, vals);
// get the buffer to write from
mp_buffer_info_t bufinfo;
uint8_t data[1];
pyb_buf_get_for_send(vals[0].u_obj, &bufinfo, data);
// get the addresses
machine_uint_t i2c_addr = vals[1].u_int << 1;
machine_uint_t mem_addr = vals[2].u_int;
HAL_StatusTypeDef status = HAL_I2C_Mem_Write(self->i2c, i2c_addr, mem_addr, I2C_MEMADD_SIZE_8BIT, bufinfo.buf, bufinfo.len, vals[3].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_I2C_Mem_Write failed with code %d", status));
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_mem_write_obj, 1, pyb_i2c_mem_write);
STATIC const mp_map_elem_t pyb_i2c_locals_dict_table[] = {
// instance methods
{ MP_OBJ_NEW_QSTR(MP_QSTR_init), (mp_obj_t)&pyb_i2c_init_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_deinit), (mp_obj_t)&pyb_i2c_deinit_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_is_ready), (mp_obj_t)&pyb_i2c_is_ready_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_scan), (mp_obj_t)&pyb_i2c_scan_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_send), (mp_obj_t)&pyb_i2c_send_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_recv), (mp_obj_t)&pyb_i2c_recv_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_mem_read), (mp_obj_t)&pyb_i2c_mem_read_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_mem_write), (mp_obj_t)&pyb_i2c_mem_write_obj },
// class constants
{ MP_OBJ_NEW_QSTR(MP_QSTR_MASTER), MP_OBJ_NEW_SMALL_INT(PYB_I2C_MASTER) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_SLAVE), MP_OBJ_NEW_SMALL_INT(PYB_I2C_SLAVE) },
};
STATIC MP_DEFINE_CONST_DICT(pyb_i2c_locals_dict, pyb_i2c_locals_dict_table);
const mp_obj_type_t pyb_i2c_type = {
{ &mp_type_type },
.name = MP_QSTR_I2C,
.print = pyb_i2c_print,
.make_new = pyb_i2c_make_new,
.locals_dict = (mp_obj_t)&pyb_i2c_locals_dict,
};
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