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stmhal/spi: Enable use of fast software SPI.

This commit is contained in:
Damien George 2016-10-04 13:51:30 +11:00
parent b0eb0d6153
commit bd925b59c3
2 changed files with 18 additions and 6 deletions
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1
stmhal/mpconfigport.h
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@ -94,6 +94,7 @@
#define MICROPY_PY_MACHINE (1)
#define MICROPY_PY_MACHINE_I2C (1)
#define MICROPY_PY_MACHINE_SPI (1)
#define MICROPY_PY_MACHINE_SPI_MIN_DELAY (0)
#define MICROPY_PY_FRAMEBUF (1)
#define MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF (1)

23
stmhal/spi.c
View File

@ -944,17 +944,28 @@ STATIC MP_DEFINE_CONST_DICT(machine_spi_locals_dict, machine_spi_locals_dict_tab
/* code for soft implementation ***********************************************/
// for the software SPI implementation, this is roughly the max baudrate
#define MAX_BAUDRATE (HAL_RCC_GetSysClockFreq() / 48)
STATIC uint32_t baudrate_from_delay_half(uint32_t delay_half) {
return 500000 / delay_half;
if (delay_half == MICROPY_PY_MACHINE_SPI_MIN_DELAY) {
return MAX_BAUDRATE;
} else {
return 500000 / delay_half;
}
}
STATIC uint32_t baudrate_to_delay_half(uint32_t baudrate) {
uint32_t delay_half = 500000 / baudrate;
// round delay_half up so that: actual_baudrate <= requested_baudrate
if (500000 % baudrate != 0) {
delay_half += 1;
if (baudrate >= MAX_BAUDRATE) {
return MICROPY_PY_MACHINE_SPI_MIN_DELAY;
} else {
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;
}
return delay_half;
}
STATIC void machine_soft_spi_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {