drivers/bus: Pull out software SPI implementation to dedicated driver.

This patch takes the software SPI implementation from extmod/machine_spi.c
and moves it to a dedicated file in drivers/bus/softspi.c.  This allows the
SPI driver to be used independently of the uPy runtime, making it a more
general component.
This commit is contained in:
Damien George
2018-03-09 17:25:58 +11:00
parent ad2a6e538c
commit 58ebeca6a9
11 changed files with 202 additions and 98 deletions

View File

@@ -38,61 +38,6 @@
#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;
// only MSB transfer is implemented
// If a port defines MICROPY_PY_MACHINE_SPI_MIN_DELAY, and the configured
// delay_half is equal to this value, then the software SPI implementation
// will run as fast as possible, limited only by CPU speed and GPIO time.
#ifdef MICROPY_PY_MACHINE_SPI_MIN_DELAY
if (delay_half == MICROPY_PY_MACHINE_SPI_MIN_DELAY) {
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);
mp_hal_pin_write(self->sck, 1 - self->polarity);
data_in = (data_in << 1) | mp_hal_pin_read(self->miso);
mp_hal_pin_write(self->sck, self->polarity);
}
if (dest != NULL) {
dest[i] = data_in;
}
}
return;
}
#endif
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;
}
}
}
/******************************************************************************/
// MicroPython bindings for generic machine.SPI
@@ -199,9 +144,9 @@ 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;
#ifdef MICROPY_HW_SOFTSPI_MIN_DELAY
if (delay_half == MICROPY_HW_SOFTSPI_MIN_DELAY) {
return MICROPY_HW_SOFTSPI_MAX_BAUDRATE;
} else
#endif
{
@@ -210,9 +155,9 @@ STATIC uint32_t baudrate_from_delay_half(uint32_t 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;
#ifdef MICROPY_HW_SOFTSPI_MIN_DELAY
if (baudrate >= MICROPY_HW_SOFTSPI_MAX_BAUDRATE) {
return MICROPY_HW_SOFTSPI_MIN_DELAY;
} else
#endif
{
@@ -229,8 +174,8 @@ STATIC void mp_machine_soft_spi_print(const mp_print_t *print, mp_obj_t self_in,
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));
baudrate_from_delay_half(self->spi.delay_half), self->spi.polarity, self->spi.phase,
mp_hal_pin_name(self->spi.sck), mp_hal_pin_name(self->spi.mosi), mp_hal_pin_name(self->spi.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) {
@@ -253,9 +198,9 @@ STATIC mp_obj_t mp_machine_soft_spi_make_new(const mp_obj_type_t *type, size_t n
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;
self->spi.delay_half = baudrate_to_delay_half(args[ARG_baudrate].u_int);
self->spi.polarity = args[ARG_polarity].u_int;
self->spi.phase = args[ARG_phase].u_int;
if (args[ARG_bits].u_int != 8) {
mp_raise_ValueError("bits must be 8");
}
@@ -267,15 +212,12 @@ STATIC mp_obj_t mp_machine_soft_spi_make_new(const mp_obj_type_t *type, size_t n
|| 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);
self->spi.sck = mp_hal_get_pin_obj(args[ARG_sck].u_obj);
self->spi.mosi = mp_hal_get_pin_obj(args[ARG_mosi].u_obj);
self->spi.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);
// configure bus
mp_soft_spi_ioctl(&self->spi, MP_SPI_IOCTL_INIT);
return MP_OBJ_FROM_PTR(self);
}
@@ -296,29 +238,31 @@ STATIC void mp_machine_soft_spi_init(mp_obj_base_t *self_in, size_t n_args, cons
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);
self->spi.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;
self->spi.polarity = args[ARG_polarity].u_int;
}
if (args[ARG_phase].u_int != -1) {
self->phase = args[ARG_phase].u_int;
self->spi.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);
self->spi.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);
self->spi.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);
self->spi.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);
// configure bus
mp_soft_spi_ioctl(&self->spi, MP_SPI_IOCTL_INIT);
}
STATIC 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;
mp_soft_spi_transfer(&self->spi, len, src, dest);
}
const mp_machine_spi_p_t mp_machine_soft_spi_p = {