circuitpython/stmhal/modstm.c

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#include <stdio.h>
#include <stdint.h>
#include "stm32f4xx_hal.h"
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "modstm.h"
// To use compile-time constants we are restricted to 31-bit numbers (a small int,
// so it fits in a Micro Python object pointer). Thus, when extracting a constant
// from an object, we must clear the MSB.
STATIC uint32_t get_read_addr(mp_obj_t addr_o, uint align) {
uint32_t addr = mp_obj_get_int(addr_o) & 0x7fffffff;
/*
if (addr < 0x10000000) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "cannot read from address %08x", addr));
}
*/
if ((addr & (align - 1)) != 0) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "address %08x is not aligned to %d bytes", addr, align));
}
return addr;
}
STATIC uint32_t get_write_addr(mp_obj_t addr_o, uint align) {
uint32_t addr = mp_obj_get_int(addr_o) & 0x7fffffff;
if (addr < 0x10000000) {
// Everything below 0x10000000 is either ROM or aliased to something higher, so we don't
// lose anything by restricting writes to this area, and we gain some safety.
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "cannot write to address %08x", addr));
}
if ((addr & (align - 1)) != 0) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "address %08x is not aligned to %d bytes", addr, align));
}
return addr;
}
typedef struct _stm_mem_obj_t {
mp_obj_base_t base;
uint32_t elem_size; // in bytes
} stm_mem_obj_t;
STATIC void stm_mem_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
stm_mem_obj_t *self = self_in;
print(env, "<%u-bit memory>", 8 * self->elem_size);
}
STATIC mp_obj_t stm_mem_subscr(mp_obj_t self_in, mp_obj_t index, mp_obj_t value) {
// TODO support slice index to read/write multiple values at once
stm_mem_obj_t *self = self_in;
if (value == MP_OBJ_NULL) {
// delete
return MP_OBJ_NOT_SUPPORTED;
} else if (value == MP_OBJ_SENTINEL) {
// load
uint32_t addr = get_read_addr(index, self->elem_size);
uint32_t val;
switch (self->elem_size) {
case 1: val = (*(uint8_t*)addr); break;
case 2: val = (*(uint16_t*)addr); break;
default: val = (*(uint32_t*)addr); break;
}
return mp_obj_new_int(val);
} else {
// store
uint32_t addr = get_write_addr(index, self->elem_size);
uint32_t val = mp_obj_get_int(value);
switch (self->elem_size) {
case 1: (*(uint8_t*)addr) = val; break;
case 2: (*(uint16_t*)addr) = val; break;
default: (*(uint32_t*)addr) = val; break;
}
return mp_const_none;
}
}
STATIC const mp_obj_type_t stm_mem_type = {
{ &mp_type_type },
.name = MP_QSTR_mem,
.print = stm_mem_print,
.subscr = stm_mem_subscr,
};
STATIC const stm_mem_obj_t stm_mem8_obj = {{&stm_mem_type}, 1};
STATIC const stm_mem_obj_t stm_mem16_obj = {{&stm_mem_type}, 2};
STATIC const stm_mem_obj_t stm_mem32_obj = {{&stm_mem_type}, 4};
STATIC const mp_map_elem_t stm_module_globals_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_stm) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_mem8), (mp_obj_t)&stm_mem8_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_mem16), (mp_obj_t)&stm_mem16_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_mem32), (mp_obj_t)&stm_mem32_obj },
#include "modstmconst.gen.c"
};
STATIC const mp_obj_dict_t stm_module_globals = {
.base = {&mp_type_dict},
.map = {
.all_keys_are_qstrs = 1,
.table_is_fixed_array = 1,
.used = ARRAY_SIZE(stm_module_globals_table),
.alloc = ARRAY_SIZE(stm_module_globals_table),
.table = (mp_map_elem_t*)stm_module_globals_table,
},
};
const mp_obj_module_t stm_module = {
.base = { &mp_type_module },
.name = MP_QSTR_stm,
.globals = (mp_obj_dict_t*)&stm_module_globals,
};