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extmod/machine_i2c: Implement I2C memory reading/writing.

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This commit is contained in:
Damien George 2016-04-12 15:52:17 +01:00
parent 9314b2df4f
commit eec8a94f04
2 changed files with 110 additions and 6 deletions
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112
extmod/machine_i2c.c
View File

@ -188,6 +188,55 @@ er:
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error"));
}
STATIC void mp_hal_i2c_write_mem(machine_i2c_obj_t *self, uint8_t addr, uint16_t memaddr, const uint8_t *src, size_t len) {
// start the I2C transaction
mp_hal_i2c_start(self);
// write the slave address and the memory address within the slave
if (!mp_hal_i2c_write_byte(self, addr << 1)) {
goto er;
}
if (!mp_hal_i2c_write_byte(self, memaddr)) {
goto er;
}
// write the buffer to the I2C memory
while (len--) {
if (!mp_hal_i2c_write_byte(self, *src++)) {
goto er;
}
}
// finish the I2C transaction
mp_hal_i2c_stop(self);
return;
er:
mp_hal_i2c_stop(self);
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error"));
}
STATIC void mp_hal_i2c_read_mem(machine_i2c_obj_t *self, uint8_t addr, uint16_t memaddr, uint8_t *dest, size_t len) {
// start the I2C transaction
mp_hal_i2c_start(self);
// write the slave address and the memory address within the slave
if (!mp_hal_i2c_write_byte(self, addr << 1)) {
goto er;
}
if (!mp_hal_i2c_write_byte(self, memaddr)) {
goto er;
}
// i2c_read will do a repeated start, and then read the I2C memory
mp_hal_i2c_read(self, addr, dest, len);
return;
er:
mp_hal_i2c_stop(self);
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error"));
}
/******************************************************************************/
// MicroPython bindings for I2C
@ -316,18 +365,69 @@ STATIC mp_obj_t machine_i2c_writeto(mp_obj_t self_in, mp_obj_t addr_in, mp_obj_t
}
STATIC MP_DEFINE_CONST_FUN_OBJ_3(machine_i2c_writeto_obj, machine_i2c_writeto);
STATIC mp_obj_t machine_i2c_readfrom_mem(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
mp_not_implemented("I2C.readfrom_mem");
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 };
static const mp_arg_t 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_n, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
//{ MP_QSTR_addrsize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, TODO
};
machine_i2c_obj_t *self = MP_OBJ_TO_PTR(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);
// create the buffer to store data into
vstr_t vstr;
vstr_init_len(&vstr, args[ARG_n].u_int);
// do the transfer
mp_hal_i2c_read_mem(self, args[ARG_addr].u_int, args[ARG_memaddr].u_int, (uint8_t*)vstr.buf, vstr.len);
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 *args, mp_map_t *kw_args) {
mp_not_implemented("I2C.readfrom_mem_into");
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 };
static const mp_arg_t 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_buf, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
//{ MP_QSTR_addrsize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, TODO
};
machine_i2c_obj_t *self = MP_OBJ_TO_PTR(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 store data into
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[ARG_buf].u_obj, &bufinfo, MP_BUFFER_WRITE);
// do the transfer
mp_hal_i2c_read_mem(self, args[ARG_addr].u_int, args[ARG_memaddr].u_int, bufinfo.buf, bufinfo.len);
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 *args, mp_map_t *kw_args) {
mp_not_implemented("I2C.writeto_mem");
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 };
static const mp_arg_t 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_buf, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
//{ MP_QSTR_addrsize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, TODO
};
machine_i2c_obj_t *self = MP_OBJ_TO_PTR(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 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
mp_hal_i2c_write_mem(self, args[ARG_addr].u_int, args[ARG_memaddr].u_int, bufinfo.buf, bufinfo.len);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_writeto_mem_obj, 1, machine_i2c_writeto_mem);

4
py/qstrdefs.h
View File

@ -699,6 +699,10 @@ Q(writeto)
Q(readfrom_mem)
Q(readfrom_mem_into)
Q(writeto_mem)
Q(addr)
Q(memaddr)
Q(n)
Q(buf)
#endif
#if MICROPY_PY_USSL