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extmod/machine_spi: Factor out software SPI code from esp8266 to extmod.

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This commit is contained in:
Damien George 2016-10-03 16:43:44 +11:00
parent a22a67661a
commit d434ce3fca
3 changed files with 54 additions and 51 deletions
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55
esp8266/modpybspi.c
View File

@ -28,68 +28,21 @@
#include <stdint.h>
#include <string.h>
#include "ets_sys.h"
#include "etshal.h"
#include "ets_alt_task.h"
#include "py/runtime.h"
#include "py/stream.h"
#include "py/mphal.h"
#include "extmod/machine_spi.h"
typedef struct _pyb_spi_obj_t {
mp_obj_base_t base;
uint32_t baudrate;
uint8_t polarity;
uint8_t phase;
mp_hal_pin_obj_t sck;
mp_hal_pin_obj_t mosi;
mp_hal_pin_obj_t miso;
} pyb_spi_obj_t;
STATIC void mp_hal_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8_t *src, uint8_t *dest) {
pyb_spi_obj_t *self = (pyb_spi_obj_t*)self_in;
// only MSB transfer is implemented
uint32_t delay_half = 500000 / self->baudrate + 1;
for (size_t i = 0; i < len; ++i) {
uint8_t data_out = src[i];
uint8_t data_in = 0;
for (int j = 0; j < 8; ++j, data_out <<= 1) {
mp_hal_pin_write(self->mosi, (data_out >> 7) & 1);
if (self->phase == 0) {
ets_delay_us(delay_half);
mp_hal_pin_write(self->sck, 1 - self->polarity);
} else {
mp_hal_pin_write(self->sck, 1 - self->polarity);
ets_delay_us(delay_half);
}
data_in = (data_in << 1) | mp_hal_pin_read(self->miso);
if (self->phase == 0) {
ets_delay_us(delay_half);
mp_hal_pin_write(self->sck, self->polarity);
} else {
mp_hal_pin_write(self->sck, self->polarity);
ets_delay_us(delay_half);
}
}
if (dest != NULL) {
dest[i] = data_in;
}
// make sure pending tasks have a chance to run
ets_loop_iter();
}
}
/******************************************************************************/
// MicroPython bindings for SPI
STATIC void pyb_spi_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
pyb_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_machine_soft_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "SPI(baudrate=%u, polarity=%u, phase=%u, sck=%u, mosi=%u, miso=%u)",
self->baudrate, self->polarity, self->phase, self->sck, self->mosi, self->miso);
}
STATIC void pyb_spi_init_helper(pyb_spi_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
STATIC void pyb_spi_init_helper(mp_machine_soft_spi_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_baudrate, ARG_polarity, ARG_phase, ARG_sck, ARG_mosi, ARG_miso };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_baudrate, MP_ARG_INT, {.u_int = -1} },
@ -130,7 +83,7 @@ STATIC void pyb_spi_init_helper(pyb_spi_obj_t *self, size_t n_args, const mp_obj
mp_obj_t pyb_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, true);
pyb_spi_obj_t *self = m_new_obj(pyb_spi_obj_t);
mp_machine_soft_spi_obj_t *self = m_new_obj(mp_machine_soft_spi_obj_t);
self->base.type = &pyb_spi_type;
// set defaults
self->baudrate = 500000;
@ -162,7 +115,7 @@ STATIC const mp_rom_map_elem_t pyb_spi_locals_dict_table[] = {
STATIC MP_DEFINE_CONST_DICT(pyb_spi_locals_dict, pyb_spi_locals_dict_table);
STATIC const mp_machine_spi_p_t pyb_spi_p = {
.transfer = mp_hal_spi_transfer,
.transfer = mp_machine_soft_spi_transfer,
};
const mp_obj_type_t pyb_spi_type = {

37
extmod/machine_spi.c
View File

@ -32,6 +32,43 @@
#if MICROPY_PY_MACHINE_SPI
void mp_machine_soft_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8_t *src, uint8_t *dest) {
mp_machine_soft_spi_obj_t *self = (mp_machine_soft_spi_obj_t*)self_in;
// only MSB transfer is implemented
uint32_t delay_half = 500000 / self->baudrate + 1;
for (size_t i = 0; i < len; ++i) {
uint8_t data_out = src[i];
uint8_t data_in = 0;
for (int j = 0; j < 8; ++j, data_out <<= 1) {
mp_hal_pin_write(self->mosi, (data_out >> 7) & 1);
if (self->phase == 0) {
mp_hal_delay_us_fast(delay_half);
mp_hal_pin_write(self->sck, 1 - self->polarity);
} else {
mp_hal_pin_write(self->sck, 1 - self->polarity);
mp_hal_delay_us_fast(delay_half);
}
data_in = (data_in << 1) | mp_hal_pin_read(self->miso);
if (self->phase == 0) {
mp_hal_delay_us_fast(delay_half);
mp_hal_pin_write(self->sck, self->polarity);
} else {
mp_hal_pin_write(self->sck, self->polarity);
mp_hal_delay_us_fast(delay_half);
}
}
if (dest != NULL) {
dest[i] = data_in;
}
// Some ports need a regular callback, but probably we don't need
// to do this every byte, or even at all.
#ifdef MICROPY_EVENT_POLL_HOOK
MICROPY_EVENT_POLL_HOOK;
#endif
}
}
STATIC void mp_machine_spi_transfer(mp_obj_t self, size_t len, const void *src, void *dest) {
mp_obj_base_t *s = (mp_obj_base_t*)MP_OBJ_TO_PTR(self);
mp_machine_spi_p_t *spi_p = (mp_machine_spi_p_t*)s->type->protocol;

13
extmod/machine_spi.h
View File

@ -28,12 +28,25 @@
#define MICROPY_INCLUDED_EXTMOD_MACHINE_SPI_H
#include "py/obj.h"
#include "py/mphal.h"
// SPI protocol
typedef struct _mp_machine_spi_p_t {
void (*transfer)(mp_obj_base_t *obj, size_t len, const uint8_t *src, uint8_t *dest);
} mp_machine_spi_p_t;
typedef struct _mp_machine_soft_spi_obj_t {
mp_obj_base_t base;
uint32_t baudrate;
uint8_t polarity;
uint8_t phase;
mp_hal_pin_obj_t sck;
mp_hal_pin_obj_t mosi;
mp_hal_pin_obj_t miso;
} mp_machine_soft_spi_obj_t;
void mp_machine_soft_spi_transfer(mp_obj_base_t *self, size_t len, const uint8_t *src, uint8_t *dest);
MP_DECLARE_CONST_FUN_OBJ(mp_machine_spi_read_obj);
MP_DECLARE_CONST_FUN_OBJ(mp_machine_spi_readinto_obj);
MP_DECLARE_CONST_FUN_OBJ(mp_machine_spi_write_obj);