Commit 1eb3c66e authored by Damien George's avatar Damien George
Browse files

extmod/machine_spi: Provide reusable software SPI class.

So long as a port defines relevant mp_hal_pin_xxx functions (and delay) it
can make use of this software SPI class without the need for additional
code.
parent d9c83974
......@@ -76,8 +76,10 @@ void ets_event_poll(void);
#include "etshal.h"
#include "gpio.h"
#include "esp8266/modmachine.h"
#define MP_HAL_PIN_FMT "%u"
#define mp_hal_pin_obj_t uint32_t
#define mp_hal_get_pin_obj(o) mp_obj_get_pin(o)
#define mp_hal_pin_name(p) (p)
void mp_hal_pin_input(mp_hal_pin_obj_t pin);
void mp_hal_pin_output(mp_hal_pin_obj_t pin);
void mp_hal_pin_open_drain(mp_hal_pin_obj_t pin);
......
......@@ -32,6 +32,12 @@
#if MICROPY_PY_MACHINE_SPI
// if a port didn't define MSB/LSB constants then provide them
#ifndef MICROPY_PY_MACHINE_SPI_MSB
#define MICROPY_PY_MACHINE_SPI_MSB (0)
#define MICROPY_PY_MACHINE_SPI_LSB (1)
#endif
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;
uint32_t delay_half = self->delay_half;
......@@ -93,6 +99,49 @@ void mp_machine_soft_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint
}
}
/******************************************************************************/
// MicroPython bindings for generic machine.SPI
STATIC mp_obj_t mp_machine_soft_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args);
mp_obj_t mp_machine_spi_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_SPI_MAKE_NEW)
// dispatch to port-specific constructor
extern mp_obj_t MICROPY_PY_MACHINE_SPI_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_SPI_MAKE_NEW(type, n_args, n_kw, args);
#else
mp_raise_ValueError("invalid SPI peripheral");
#endif
}
--n_args;
++args;
}
// software SPI
return mp_machine_soft_spi_make_new(type, n_args, n_kw, args);
}
STATIC mp_obj_t machine_spi_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
mp_obj_base_t *s = (mp_obj_base_t*)MP_OBJ_TO_PTR(args[0]);
mp_machine_spi_p_t *spi_p = (mp_machine_spi_p_t*)s->type->protocol;
spi_p->init(s, n_args - 1, args + 1, kw_args);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_spi_init_obj, 1, machine_spi_init);
STATIC mp_obj_t machine_spi_deinit(mp_obj_t self) {
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;
if (spi_p->deinit != NULL) {
spi_p->deinit(s);
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_spi_deinit_obj, machine_spi_deinit);
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;
......@@ -138,4 +187,159 @@ STATIC mp_obj_t mp_machine_spi_write_readinto(mp_obj_t self, mp_obj_t wr_buf, mp
}
MP_DEFINE_CONST_FUN_OBJ_3(mp_machine_spi_write_readinto_obj, mp_machine_spi_write_readinto);
STATIC const mp_rom_map_elem_t machine_spi_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&machine_spi_init_obj) },
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&machine_spi_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_machine_spi_read_obj) },
{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_machine_spi_readinto_obj) },
{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_machine_spi_write_obj) },
{ MP_ROM_QSTR(MP_QSTR_write_readinto), MP_ROM_PTR(&mp_machine_spi_write_readinto_obj) },
{ MP_ROM_QSTR(MP_QSTR_MSB), MP_ROM_INT(MICROPY_PY_MACHINE_SPI_MSB) },
{ MP_ROM_QSTR(MP_QSTR_LSB), MP_ROM_INT(MICROPY_PY_MACHINE_SPI_LSB) },
};
MP_DEFINE_CONST_DICT(mp_machine_spi_locals_dict, machine_spi_locals_dict_table);
/******************************************************************************/
// Implementation of soft SPI
STATIC uint32_t baudrate_from_delay_half(uint32_t delay_half) {
#ifdef MICROPY_PY_MACHINE_SPI_MIN_DELAY
if (delay_half == MICROPY_PY_MACHINE_SPI_MIN_DELAY) {
return MICROPY_PY_MACHINE_SPI_MAX_BAUDRATE;
} else
#endif
{
return 500000 / delay_half;
}
}
STATIC uint32_t baudrate_to_delay_half(uint32_t baudrate) {
#ifdef MICROPY_PY_MACHINE_SPI_MIN_DELAY
if (baudrate >= MICROPY_PY_MACHINE_SPI_MAX_BAUDRATE) {
return MICROPY_PY_MACHINE_SPI_MIN_DELAY;
} else
#endif
{
uint32_t delay_half = 500000 / baudrate;
// round delay_half up so that: actual_baudrate <= requested_baudrate
if (500000 % baudrate != 0) {
delay_half += 1;
}
return delay_half;
}
}
STATIC void mp_machine_soft_spi_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
mp_machine_soft_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "SoftSPI(baudrate=%u, polarity=%u, phase=%u,"
" sck=" MP_HAL_PIN_FMT ", mosi=" MP_HAL_PIN_FMT ", miso=" MP_HAL_PIN_FMT ")",
baudrate_from_delay_half(self->delay_half), self->polarity, self->phase,
mp_hal_pin_name(self->sck), mp_hal_pin_name(self->mosi), mp_hal_pin_name(self->miso));
}
STATIC mp_obj_t mp_machine_soft_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
enum { ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits, ARG_firstbit, ARG_sck, ARG_mosi, ARG_miso };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_baudrate, MP_ARG_INT, {.u_int = 500000} },
{ MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_phase, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_bits, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} },
{ MP_QSTR_firstbit, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = MICROPY_PY_MACHINE_SPI_MSB} },
{ MP_QSTR_sck, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_mosi, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_miso, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// create new object
mp_machine_soft_spi_obj_t *self = m_new_obj(mp_machine_soft_spi_obj_t);
self->base.type = &mp_machine_soft_spi_type;
// set parameters
self->delay_half = baudrate_to_delay_half(args[ARG_baudrate].u_int);
self->polarity = args[ARG_polarity].u_int;
self->phase = args[ARG_phase].u_int;
if (args[ARG_bits].u_int != 8) {
mp_raise_ValueError("bits must be 8");
}
if (args[ARG_firstbit].u_int != MICROPY_PY_MACHINE_SPI_MSB) {
mp_raise_ValueError("firstbit must be MSB");
}
if (args[ARG_sck].u_obj == MP_OBJ_NULL
|| args[ARG_mosi].u_obj == MP_OBJ_NULL
|| args[ARG_miso].u_obj == MP_OBJ_NULL) {
mp_raise_ValueError("must specify all of sck/mosi/miso");
}
self->sck = mp_hal_get_pin_obj(args[ARG_sck].u_obj);
self->mosi = mp_hal_get_pin_obj(args[ARG_mosi].u_obj);
self->miso = mp_hal_get_pin_obj(args[ARG_miso].u_obj);
// configure pins
mp_hal_pin_write(self->sck, self->polarity);
mp_hal_pin_output(self->sck);
mp_hal_pin_output(self->mosi);
mp_hal_pin_input(self->miso);
return MP_OBJ_FROM_PTR(self);
}
STATIC void mp_machine_soft_spi_init(mp_obj_base_t *self_in, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
mp_machine_soft_spi_obj_t *self = (mp_machine_soft_spi_obj_t*)self_in;
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} },
{ MP_QSTR_polarity, MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_phase, MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_sck, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_mosi, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_miso, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
};
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);
if (args[ARG_baudrate].u_int != -1) {
self->delay_half = baudrate_to_delay_half(args[ARG_baudrate].u_int);
}
if (args[ARG_polarity].u_int != -1) {
self->polarity = args[ARG_polarity].u_int;
}
if (args[ARG_phase].u_int != -1) {
self->phase = args[ARG_phase].u_int;
}
if (args[ARG_sck].u_obj != MP_OBJ_NULL) {
self->sck = mp_hal_get_pin_obj(args[ARG_sck].u_obj);
}
if (args[ARG_mosi].u_obj != MP_OBJ_NULL) {
self->mosi = mp_hal_get_pin_obj(args[ARG_mosi].u_obj);
}
if (args[ARG_miso].u_obj != MP_OBJ_NULL) {
self->miso = mp_hal_get_pin_obj(args[ARG_miso].u_obj);
}
// configure pins
mp_hal_pin_write(self->sck, self->polarity);
mp_hal_pin_output(self->sck);
mp_hal_pin_output(self->mosi);
mp_hal_pin_input(self->miso);
}
STATIC const mp_machine_spi_p_t mp_machine_soft_spi_p = {
.init = mp_machine_soft_spi_init,
.deinit = NULL,
.transfer = mp_machine_soft_spi_transfer,
};
const mp_obj_type_t mp_machine_soft_spi_type = {
{ &mp_type_type },
.name = MP_QSTR_SoftSPI,
.print = mp_machine_soft_spi_print,
.make_new = mp_machine_spi_make_new, // delegate to master constructor
.protocol = &mp_machine_soft_spi_p,
.locals_dict = (mp_obj_dict_t*)&mp_machine_spi_locals_dict,
};
#endif // MICROPY_PY_MACHINE_SPI
......@@ -32,6 +32,8 @@
// SPI protocol
typedef struct _mp_machine_spi_p_t {
void (*init)(mp_obj_base_t *obj, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args);
void (*deinit)(mp_obj_base_t *obj); // can be NULL
void (*transfer)(mp_obj_base_t *obj, size_t len, const uint8_t *src, uint8_t *dest);
} mp_machine_spi_p_t;
......@@ -45,8 +47,13 @@ typedef struct _mp_machine_soft_spi_obj_t {
mp_hal_pin_obj_t miso;
} mp_machine_soft_spi_obj_t;
extern const mp_obj_type_t mp_machine_soft_spi_type;
extern const mp_obj_dict_t mp_machine_spi_locals_dict;
void mp_machine_soft_spi_transfer(mp_obj_base_t *self, size_t len, const uint8_t *src, uint8_t *dest);
mp_obj_t mp_machine_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args);
MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(mp_machine_spi_read_obj);
MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(mp_machine_spi_readinto_obj);
MP_DECLARE_CONST_FUN_OBJ_2(mp_machine_spi_write_obj);
......
......@@ -106,6 +106,7 @@
#define MICROPY_PY_MACHINE_I2C_MAKE_NEW machine_hard_i2c_make_new
#define MICROPY_PY_MACHINE_SPI (1)
#define MICROPY_PY_MACHINE_SPI_MIN_DELAY (0)
#define MICROPY_PY_MACHINE_SPI_MAX_BAUDRATE (HAL_RCC_GetSysClockFreq() / 48)
#define MICROPY_PY_FRAMEBUF (1)
#ifndef MICROPY_PY_USOCKET
......
......@@ -48,6 +48,7 @@ static inline mp_uint_t mp_hal_ticks_cpu(void) {
#include "stmhal/pin.h"
#define MP_HAL_PIN_FMT "%q"
#define MP_HAL_PIN_MODE_INPUT (0)
#define MP_HAL_PIN_MODE_OUTPUT (1)
#define MP_HAL_PIN_MODE_ALT (2)
......@@ -60,6 +61,7 @@ static inline mp_uint_t mp_hal_ticks_cpu(void) {
#define mp_hal_pin_obj_t const pin_obj_t*
#define mp_hal_get_pin_obj(o) pin_find(o)
#define mp_hal_pin_name(p) ((p)->name)
#define mp_hal_pin_input(p) mp_hal_pin_config((p), MP_HAL_PIN_MODE_INPUT, MP_HAL_PIN_PULL_NONE, 0)
#define mp_hal_pin_output(p) mp_hal_pin_config((p), MP_HAL_PIN_MODE_OUTPUT, MP_HAL_PIN_PULL_NONE, 0)
#define mp_hal_pin_open_drain(p) mp_hal_pin_config((p), MP_HAL_PIN_MODE_OPEN_DRAIN, MP_HAL_PIN_PULL_NONE, 0)
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment