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circuitpython/extmod/machine_i2c.c
Michael Buesch cef678b2db extmod/machine_i2c: Fix buffer overrun if 'addrsize' is bigger than 32. 
The memory operation functions read_mem() and write_mem() create a
temporary buffer on the local C stack for the address bytes with the size
of 4 bytes.  This buffer is filled in a loop from the user supplied address
and address length.  If the user supplied 'addrsize' is bigger than 32, the
local buffer is overrun.

Fix this by raising an exception for invalid 'addrsize' values.

Signed-off-by: Michael Buesch <m@bues.ch>
2020-08-27 12:39:11 +10:00

712 lines
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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 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 <stdint.h>
#include <string.h>
#include "py/mperrno.h"
#include "py/mphal.h"
#include "py/runtime.h"
#include "extmod/machine_i2c.h"
#if MICROPY_PY_MACHINE_I2C
typedef mp_machine_soft_i2c_obj_t machine_i2c_obj_t;
STATIC void mp_hal_i2c_delay(machine_i2c_obj_t *self) {
// We need to use an accurate delay to get acceptable I2C
// speeds (eg 1us should be not much more than 1us).
mp_hal_delay_us_fast(self->us_delay);
}
STATIC void mp_hal_i2c_scl_low(machine_i2c_obj_t *self) {
mp_hal_pin_od_low(self->scl);
}
STATIC int mp_hal_i2c_scl_release(machine_i2c_obj_t *self) {
uint32_t count = self->us_timeout;
mp_hal_pin_od_high(self->scl);
mp_hal_i2c_delay(self);
// For clock stretching, wait for the SCL pin to be released, with timeout.
for (; mp_hal_pin_read(self->scl) == 0 && count; --count) {
mp_hal_delay_us_fast(1);
}
if (count == 0) {
return -MP_ETIMEDOUT;
}
return 0; // success
}
STATIC void mp_hal_i2c_sda_low(machine_i2c_obj_t *self) {
mp_hal_pin_od_low(self->sda);
}
STATIC void mp_hal_i2c_sda_release(machine_i2c_obj_t *self) {
mp_hal_pin_od_high(self->sda);
}
STATIC int mp_hal_i2c_sda_read(machine_i2c_obj_t *self) {
return mp_hal_pin_read(self->sda);
}
STATIC int mp_hal_i2c_start(machine_i2c_obj_t *self) {
mp_hal_i2c_sda_release(self);
mp_hal_i2c_delay(self);
int ret = mp_hal_i2c_scl_release(self);
if (ret != 0) {
return ret;
}
mp_hal_i2c_sda_low(self);
mp_hal_i2c_delay(self);
return 0; // success
}
STATIC int mp_hal_i2c_stop(machine_i2c_obj_t *self) {
mp_hal_i2c_delay(self);
mp_hal_i2c_sda_low(self);
mp_hal_i2c_delay(self);
int ret = mp_hal_i2c_scl_release(self);
mp_hal_i2c_sda_release(self);
mp_hal_i2c_delay(self);
return ret;
}
STATIC void mp_hal_i2c_init(machine_i2c_obj_t *self, uint32_t freq) {
self->us_delay = 500000 / freq;
if (self->us_delay == 0) {
self->us_delay = 1;
}
mp_hal_pin_open_drain(self->scl);
mp_hal_pin_open_drain(self->sda);
mp_hal_i2c_stop(self); // ignore error
}
// return value:
// 0 - byte written and ack received
// 1 - byte written and nack received
// <0 - error, with errno being the negative of the return value
STATIC int mp_hal_i2c_write_byte(machine_i2c_obj_t *self, uint8_t val) {
mp_hal_i2c_delay(self);
mp_hal_i2c_scl_low(self);
for (int i = 7; i >= 0; i--) {
if ((val >> i) & 1) {
mp_hal_i2c_sda_release(self);
} else {
mp_hal_i2c_sda_low(self);
}
mp_hal_i2c_delay(self);
int ret = mp_hal_i2c_scl_release(self);
if (ret != 0) {
mp_hal_i2c_sda_release(self);
return ret;
}
mp_hal_i2c_scl_low(self);
}
mp_hal_i2c_sda_release(self);
mp_hal_i2c_delay(self);
int ret = mp_hal_i2c_scl_release(self);
if (ret != 0) {
return ret;
}
int ack = mp_hal_i2c_sda_read(self);
mp_hal_i2c_delay(self);
mp_hal_i2c_scl_low(self);
return ack;
}
// return value:
// 0 - success
// <0 - error, with errno being the negative of the return value
STATIC int mp_hal_i2c_read_byte(machine_i2c_obj_t *self, uint8_t *val, int nack) {
mp_hal_i2c_delay(self);
mp_hal_i2c_scl_low(self);
mp_hal_i2c_delay(self);
uint8_t data = 0;
for (int i = 7; i >= 0; i--) {
int ret = mp_hal_i2c_scl_release(self);
if (ret != 0) {
return ret;
}
data = (data << 1) | mp_hal_i2c_sda_read(self);
mp_hal_i2c_scl_low(self);
mp_hal_i2c_delay(self);
}
*val = data;
// send ack/nack bit
if (!nack) {
mp_hal_i2c_sda_low(self);
}
mp_hal_i2c_delay(self);
int ret = mp_hal_i2c_scl_release(self);
if (ret != 0) {
mp_hal_i2c_sda_release(self);
return ret;
}
mp_hal_i2c_scl_low(self);
mp_hal_i2c_sda_release(self);
return 0; // success
}
// return value:
// >=0 - success; for read it's 0, for write it's number of acks received
// <0 - error, with errno being the negative of the return value
int mp_machine_soft_i2c_transfer(mp_obj_base_t *self_in, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags) {
machine_i2c_obj_t *self = (machine_i2c_obj_t *)self_in;
// start the I2C transaction
int ret = mp_hal_i2c_start(self);
if (ret != 0) {
return ret;
}
// write the slave address
ret = mp_hal_i2c_write_byte(self, (addr << 1) | (flags & MP_MACHINE_I2C_FLAG_READ));
if (ret < 0) {
return ret;
} else if (ret != 0) {
// nack received, release the bus cleanly
mp_hal_i2c_stop(self);
return -MP_ENODEV;
}
int transfer_ret = 0;
for (; n--; ++bufs) {
size_t len = bufs->len;
uint8_t *buf = bufs->buf;
if (flags & MP_MACHINE_I2C_FLAG_READ) {
// read bytes from the slave into the given buffer(s)
while (len--) {
ret = mp_hal_i2c_read_byte(self, buf++, (n | len) == 0);
if (ret != 0) {
return ret;
}
}
} else {
// write bytes from the given buffer(s) to the slave
while (len--) {
ret = mp_hal_i2c_write_byte(self, *buf++);
if (ret < 0) {
return ret;
} else if (ret != 0) {
// nack received, stop sending
n = 0;
break;
}
++transfer_ret; // count the number of acks
}
}
}
// finish the I2C transaction
if (flags & MP_MACHINE_I2C_FLAG_STOP) {
ret = mp_hal_i2c_stop(self);
if (ret != 0) {
return ret;
}
}
return transfer_ret;
}
/******************************************************************************/
// Generic helper functions
// For use by ports that require a single buffer of data for a read/write transfer
int mp_machine_i2c_transfer_adaptor(mp_obj_base_t *self, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags) {
size_t len;
uint8_t *buf;
if (n == 1) {
// Use given single buffer
len = bufs[0].len;
buf = bufs[0].buf;
} else {
// Combine buffers into a single one
len = 0;
for (size_t i = 0; i < n; ++i) {
len += bufs[i].len;
}
buf = m_new(uint8_t, len);
if (!(flags & MP_MACHINE_I2C_FLAG_READ)) {
len = 0;
for (size_t i = 0; i < n; ++i) {
memcpy(buf + len, bufs[i].buf, bufs[i].len);
len += bufs[i].len;
}
}
}
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
int ret = i2c_p->transfer_single(self, addr, len, buf, flags);
if (n > 1) {
if (flags & MP_MACHINE_I2C_FLAG_READ) {
// Copy data from single buffer to individual ones
len = 0;
for (size_t i = 0; i < n; ++i) {
memcpy(bufs[i].buf, buf + len, bufs[i].len);
len += bufs[i].len;
}
}
m_del(uint8_t, buf, len);
}
return ret;
}
STATIC int mp_machine_i2c_readfrom(mp_obj_base_t *self, uint16_t addr, uint8_t *dest, size_t len, bool stop) {
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
mp_machine_i2c_buf_t buf = {.len = len, .buf = dest};
unsigned int flags = MP_MACHINE_I2C_FLAG_READ | (stop ? MP_MACHINE_I2C_FLAG_STOP : 0);
return i2c_p->transfer(self, addr, 1, &buf, flags);
}
STATIC int mp_machine_i2c_writeto(mp_obj_base_t *self, uint16_t addr, const uint8_t *src, size_t len, bool stop) {
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
mp_machine_i2c_buf_t buf = {.len = len, .buf = (uint8_t *)src};
unsigned int flags = stop ? MP_MACHINE_I2C_FLAG_STOP : 0;
return i2c_p->transfer(self, addr, 1, &buf, flags);
}
/******************************************************************************/
// MicroPython bindings for I2C
STATIC void machine_i2c_obj_init_helper(machine_i2c_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_scl, ARG_sda, ARG_freq, ARG_timeout };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 255} },
};
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);
self->scl = mp_hal_get_pin_obj(args[ARG_scl].u_obj);
self->sda = mp_hal_get_pin_obj(args[ARG_sda].u_obj);
self->us_timeout = args[ARG_timeout].u_int;
mp_hal_i2c_init(self, args[ARG_freq].u_int);
}
STATIC mp_obj_t machine_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
// check the id argument, if given
if (n_args > 0) {
if (args[0] != MP_OBJ_NEW_SMALL_INT(-1)) {
#if defined(MICROPY_PY_MACHINE_I2C_MAKE_NEW)
// dispatch to port-specific constructor
extern mp_obj_t MICROPY_PY_MACHINE_I2C_MAKE_NEW(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args);
return MICROPY_PY_MACHINE_I2C_MAKE_NEW(type, n_args, n_kw, args);
#else
mp_raise_ValueError(MP_ERROR_TEXT("invalid I2C peripheral"));
#endif
}
--n_args;
++args;
}
// create new soft I2C object
machine_i2c_obj_t *self = m_new_obj(machine_i2c_obj_t);
self->base.type = &machine_i2c_type;
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
machine_i2c_obj_init_helper(self, n_args, args, &kw_args);
return MP_OBJ_FROM_PTR(self);
}
STATIC mp_obj_t machine_i2c_obj_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
machine_i2c_obj_init_helper(MP_OBJ_TO_PTR(args[0]), n_args - 1, args + 1, kw_args);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_init_obj, 1, machine_i2c_obj_init);
STATIC mp_obj_t machine_i2c_scan(mp_obj_t self_in) {
mp_obj_base_t *self = MP_OBJ_TO_PTR(self_in);
mp_obj_t list = mp_obj_new_list(0, NULL);
// 7-bit addresses 0b0000xxx and 0b1111xxx are reserved
for (int addr = 0x08; addr < 0x78; ++addr) {
int ret = mp_machine_i2c_writeto(self, addr, NULL, 0, true);
if (ret == 0) {
mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr));
}
}
return list;
}
MP_DEFINE_CONST_FUN_OBJ_1(machine_i2c_scan_obj, machine_i2c_scan);
STATIC mp_obj_t machine_i2c_start(mp_obj_t self_in) {
mp_obj_base_t *self = (mp_obj_base_t *)MP_OBJ_TO_PTR(self_in);
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
if (i2c_p->start == NULL) {
mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("I2C operation not supported"));
}
int ret = i2c_p->start(self);
if (ret != 0) {
mp_raise_OSError(-ret);
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_1(machine_i2c_start_obj, machine_i2c_start);
STATIC mp_obj_t machine_i2c_stop(mp_obj_t self_in) {
mp_obj_base_t *self = (mp_obj_base_t *)MP_OBJ_TO_PTR(self_in);
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
if (i2c_p->stop == NULL) {
mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("I2C operation not supported"));
}
int ret = i2c_p->stop(self);
if (ret != 0) {
mp_raise_OSError(-ret);
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_1(machine_i2c_stop_obj, machine_i2c_stop);
STATIC mp_obj_t machine_i2c_readinto(size_t n_args, const mp_obj_t *args) {
mp_obj_base_t *self = (mp_obj_base_t *)MP_OBJ_TO_PTR(args[0]);
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
if (i2c_p->read == NULL) {
mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("I2C operation not supported"));
}
// get the buffer to read into
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_WRITE);
// work out if we want to send a nack at the end
bool nack = (n_args == 2) ? true : mp_obj_is_true(args[2]);
// do the read
int ret = i2c_p->read(self, bufinfo.buf, bufinfo.len, nack);
if (ret != 0) {
mp_raise_OSError(-ret);
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_i2c_readinto_obj, 2, 3, machine_i2c_readinto);
STATIC mp_obj_t machine_i2c_write(mp_obj_t self_in, mp_obj_t buf_in) {
mp_obj_base_t *self = (mp_obj_base_t *)MP_OBJ_TO_PTR(self_in);
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
if (i2c_p->write == NULL) {
mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("I2C operation not supported"));
}
// get the buffer to write from
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_READ);
// do the write
int ret = i2c_p->write(self, bufinfo.buf, bufinfo.len);
if (ret < 0) {
mp_raise_OSError(-ret);
}
// return number of acks received
return MP_OBJ_NEW_SMALL_INT(ret);
}
MP_DEFINE_CONST_FUN_OBJ_2(machine_i2c_write_obj, machine_i2c_write);
STATIC mp_obj_t machine_i2c_readfrom(size_t n_args, const mp_obj_t *args) {
mp_obj_base_t *self = (mp_obj_base_t *)MP_OBJ_TO_PTR(args[0]);
mp_int_t addr = mp_obj_get_int(args[1]);
vstr_t vstr;
vstr_init_len(&vstr, mp_obj_get_int(args[2]));
bool stop = (n_args == 3) ? true : mp_obj_is_true(args[3]);
int ret = mp_machine_i2c_readfrom(self, addr, (uint8_t *)vstr.buf, vstr.len, stop);
if (ret < 0) {
mp_raise_OSError(-ret);
}
return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_i2c_readfrom_obj, 3, 4, machine_i2c_readfrom);
STATIC mp_obj_t machine_i2c_readfrom_into(size_t n_args, const mp_obj_t *args) {
mp_obj_base_t *self = (mp_obj_base_t *)MP_OBJ_TO_PTR(args[0]);
mp_int_t addr = mp_obj_get_int(args[1]);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[2], &bufinfo, MP_BUFFER_WRITE);
bool stop = (n_args == 3) ? true : mp_obj_is_true(args[3]);
int ret = mp_machine_i2c_readfrom(self, addr, bufinfo.buf, bufinfo.len, stop);
if (ret < 0) {
mp_raise_OSError(-ret);
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_i2c_readfrom_into_obj, 3, 4, machine_i2c_readfrom_into);
STATIC mp_obj_t machine_i2c_writeto(size_t n_args, const mp_obj_t *args) {
mp_obj_base_t *self = (mp_obj_base_t *)MP_OBJ_TO_PTR(args[0]);
mp_int_t addr = mp_obj_get_int(args[1]);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[2], &bufinfo, MP_BUFFER_READ);
bool stop = (n_args == 3) ? true : mp_obj_is_true(args[3]);
int ret = mp_machine_i2c_writeto(self, addr, bufinfo.buf, bufinfo.len, stop);
if (ret < 0) {
mp_raise_OSError(-ret);
}
// return number of acks received
return MP_OBJ_NEW_SMALL_INT(ret);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_i2c_writeto_obj, 3, 4, machine_i2c_writeto);
STATIC mp_obj_t machine_i2c_writevto(size_t n_args, const mp_obj_t *args) {
mp_obj_base_t *self = (mp_obj_base_t *)MP_OBJ_TO_PTR(args[0]);
mp_int_t addr = mp_obj_get_int(args[1]);
// Get the list of data buffer(s) to write
size_t nitems;
const mp_obj_t *items;
mp_obj_get_array(args[2], &nitems, (mp_obj_t **)&items);
// Get the stop argument
bool stop = (n_args == 3) ? true : mp_obj_is_true(args[3]);
// Extract all buffer data, skipping zero-length buffers
size_t alloc = nitems == 0 ? 1 : nitems;
size_t nbufs = 0;
mp_machine_i2c_buf_t *bufs = mp_local_alloc(alloc * sizeof(mp_machine_i2c_buf_t));
for (; nitems--; ++items) {
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(*items, &bufinfo, MP_BUFFER_READ);
if (bufinfo.len > 0) {
bufs[nbufs].len = bufinfo.len;
bufs[nbufs++].buf = bufinfo.buf;
}
}
// Make sure there is at least one buffer, empty if needed
if (nbufs == 0) {
bufs[0].len = 0;
bufs[0].buf = NULL;
nbufs = 1;
}
// Do the I2C transfer
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
int ret = i2c_p->transfer(self, addr, nbufs, bufs, stop ? MP_MACHINE_I2C_FLAG_STOP : 0);
mp_local_free(bufs);
if (ret < 0) {
mp_raise_OSError(-ret);
}
// Return number of acks received
return MP_OBJ_NEW_SMALL_INT(ret);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_i2c_writevto_obj, 3, 4, machine_i2c_writevto);
STATIC size_t fill_memaddr_buf(uint8_t *memaddr_buf, uint32_t memaddr, uint8_t addrsize) {
size_t memaddr_len = 0;
if ((addrsize & 7) != 0 || addrsize > 32) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid addrsize"));
}
for (int16_t i = addrsize - 8; i >= 0; i -= 8) {
memaddr_buf[memaddr_len++] = memaddr >> i;
}
return memaddr_len;
}
STATIC int read_mem(mp_obj_t self_in, uint16_t addr, uint32_t memaddr, uint8_t addrsize, uint8_t *buf, size_t len) {
mp_obj_base_t *self = (mp_obj_base_t *)MP_OBJ_TO_PTR(self_in);
// Create buffer with memory address
uint8_t memaddr_buf[4];
size_t memaddr_len = fill_memaddr_buf(&memaddr_buf[0], memaddr, addrsize);
int ret = mp_machine_i2c_writeto(self, addr, memaddr_buf, memaddr_len, false);
if (ret != memaddr_len) {
// must generate STOP
mp_machine_i2c_writeto(self, addr, NULL, 0, true);
return ret;
}
return mp_machine_i2c_readfrom(self, addr, buf, len, true);
}
STATIC int write_mem(mp_obj_t self_in, uint16_t addr, uint32_t memaddr, uint8_t addrsize, const uint8_t *buf, size_t len) {
mp_obj_base_t *self = (mp_obj_base_t *)MP_OBJ_TO_PTR(self_in);
// Create buffer with memory address
uint8_t memaddr_buf[4];
size_t memaddr_len = fill_memaddr_buf(&memaddr_buf[0], memaddr, addrsize);
// Create partial write buffers
mp_machine_i2c_buf_t bufs[2] = {
{.len = memaddr_len, .buf = memaddr_buf},
{.len = len, .buf = (uint8_t *)buf},
};
// Do I2C transfer
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
return i2c_p->transfer(self, addr, 2, bufs, MP_MACHINE_I2C_FLAG_STOP);
}
STATIC const mp_arg_t machine_i2c_mem_allowed_args[] = {
{ MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_memaddr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_arg, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_addrsize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} },
};
STATIC mp_obj_t machine_i2c_readfrom_mem(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_addr, ARG_memaddr, ARG_n, ARG_addrsize };
mp_arg_val_t args[MP_ARRAY_SIZE(machine_i2c_mem_allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args,
MP_ARRAY_SIZE(machine_i2c_mem_allowed_args), machine_i2c_mem_allowed_args, args);
// create the buffer to store data into
vstr_t vstr;
vstr_init_len(&vstr, mp_obj_get_int(args[ARG_n].u_obj));
// do the transfer
int ret = read_mem(pos_args[0], args[ARG_addr].u_int, args[ARG_memaddr].u_int,
args[ARG_addrsize].u_int, (uint8_t *)vstr.buf, vstr.len);
if (ret < 0) {
mp_raise_OSError(-ret);
}
return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
}
MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_readfrom_mem_obj, 1, machine_i2c_readfrom_mem);
STATIC mp_obj_t machine_i2c_readfrom_mem_into(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_addr, ARG_memaddr, ARG_buf, ARG_addrsize };
mp_arg_val_t args[MP_ARRAY_SIZE(machine_i2c_mem_allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args,
MP_ARRAY_SIZE(machine_i2c_mem_allowed_args), machine_i2c_mem_allowed_args, args);
// get the buffer to store data into
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[ARG_buf].u_obj, &bufinfo, MP_BUFFER_WRITE);
// do the transfer
int ret = read_mem(pos_args[0], args[ARG_addr].u_int, args[ARG_memaddr].u_int,
args[ARG_addrsize].u_int, bufinfo.buf, bufinfo.len);
if (ret < 0) {
mp_raise_OSError(-ret);
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_readfrom_mem_into_obj, 1, machine_i2c_readfrom_mem_into);
STATIC mp_obj_t machine_i2c_writeto_mem(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_addr, ARG_memaddr, ARG_buf, ARG_addrsize };
mp_arg_val_t args[MP_ARRAY_SIZE(machine_i2c_mem_allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args,
MP_ARRAY_SIZE(machine_i2c_mem_allowed_args), machine_i2c_mem_allowed_args, args);
// get the buffer to write the data from
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[ARG_buf].u_obj, &bufinfo, MP_BUFFER_READ);
// do the transfer
int ret = write_mem(pos_args[0], args[ARG_addr].u_int, args[ARG_memaddr].u_int,
args[ARG_addrsize].u_int, bufinfo.buf, bufinfo.len);
if (ret < 0) {
mp_raise_OSError(-ret);
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_writeto_mem_obj, 1, machine_i2c_writeto_mem);
STATIC const mp_rom_map_elem_t machine_i2c_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&machine_i2c_init_obj) },
{ MP_ROM_QSTR(MP_QSTR_scan), MP_ROM_PTR(&machine_i2c_scan_obj) },
// primitive I2C operations
{ MP_ROM_QSTR(MP_QSTR_start), MP_ROM_PTR(&machine_i2c_start_obj) },
{ MP_ROM_QSTR(MP_QSTR_stop), MP_ROM_PTR(&machine_i2c_stop_obj) },
{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&machine_i2c_readinto_obj) },
{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&machine_i2c_write_obj) },
// standard bus operations
{ MP_ROM_QSTR(MP_QSTR_readfrom), MP_ROM_PTR(&machine_i2c_readfrom_obj) },
{ MP_ROM_QSTR(MP_QSTR_readfrom_into), MP_ROM_PTR(&machine_i2c_readfrom_into_obj) },
{ MP_ROM_QSTR(MP_QSTR_writeto), MP_ROM_PTR(&machine_i2c_writeto_obj) },
{ MP_ROM_QSTR(MP_QSTR_writevto), MP_ROM_PTR(&machine_i2c_writevto_obj) },
// memory operations
{ MP_ROM_QSTR(MP_QSTR_readfrom_mem), MP_ROM_PTR(&machine_i2c_readfrom_mem_obj) },
{ MP_ROM_QSTR(MP_QSTR_readfrom_mem_into), MP_ROM_PTR(&machine_i2c_readfrom_mem_into_obj) },
{ MP_ROM_QSTR(MP_QSTR_writeto_mem), MP_ROM_PTR(&machine_i2c_writeto_mem_obj) },
};
MP_DEFINE_CONST_DICT(mp_machine_soft_i2c_locals_dict, machine_i2c_locals_dict_table);
int mp_machine_soft_i2c_read(mp_obj_base_t *self_in, uint8_t *dest, size_t len, bool nack) {
machine_i2c_obj_t *self = (machine_i2c_obj_t *)self_in;
while (len--) {
int ret = mp_hal_i2c_read_byte(self, dest++, nack && (len == 0));
if (ret != 0) {
return ret;
}
}
return 0; // success
}
int mp_machine_soft_i2c_write(mp_obj_base_t *self_in, const uint8_t *src, size_t len) {
machine_i2c_obj_t *self = (machine_i2c_obj_t *)self_in;
int num_acks = 0;
while (len--) {
int ret = mp_hal_i2c_write_byte(self, *src++);
if (ret < 0) {
return ret;
} else if (ret != 0) {
// nack received, stop sending
break;
}
++num_acks;
}
return num_acks;
}
STATIC const mp_machine_i2c_p_t mp_machine_soft_i2c_p = {
.start = (int (*)(mp_obj_base_t *))mp_hal_i2c_start,
.stop = (int (*)(mp_obj_base_t *))mp_hal_i2c_stop,
.read = mp_machine_soft_i2c_read,
.write = mp_machine_soft_i2c_write,
.transfer = mp_machine_soft_i2c_transfer,
};
const mp_obj_type_t machine_i2c_type = {
{ &mp_type_type },
.name = MP_QSTR_I2C,
.make_new = machine_i2c_make_new,
.protocol = &mp_machine_soft_i2c_p,
.locals_dict = (mp_obj_dict_t *)&mp_machine_soft_i2c_locals_dict,
};
#endif // MICROPY_PY_MACHINE_I2C
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