8000 rp2/machine_uart: Implement a Python UART IRQ handler. · projectgus/micropython@01c046d · GitHub
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rp2/machine_uart: Implement a Python UART IRQ handler.
Supported trigger names: IRQ_RXIDLE, IRQ_TXIDLE, IRQ_BREAK - IRQ_RXIDLE: The handler for IRQ_RXIDLE is called reliably 31 UART bit times after the last incoming data. - IRQ_TXIDLE: This IRQ is triggered after at least >5 characters are sent at once. It is triggered when the TX FIFO falls below 4 elements. At that time, up to 5 bytes may still be in the FIFO and output shift register. - IRQ_BREAK: The IRQ triggers if a BREAK state is detected at RX. Properties & side effects: - After a BREAK, a valid character must be received before another break can be detected. - Each break puts a 0xff character into the input buffer. The irq.flags() value is cleared only with a new wanted event. Do not change the flags otherwise. Signed-off-by: robert-hh <robert@hammelrath.com>
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‎ports/rp2/machine_uart.c

Lines changed: 121 additions & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -80,6 +80,10 @@
8080

8181
#define UART_HWCONTROL_CTS (1)
8282
#define UART_HWCONTROL_RTS (2)
83+
// OR-ed IRQ flags which are allowed to be used by the user
84+
#define MP_UART_ALLOWED_FLAGS (UART_UARTMIS_RTMIS_BITS | UART_UARTMIS_TXMIS_BITS | UART_UARTMIS_BEMIS_BITS)
85+
#define UART_FIFO_SIZE_RX (32)
86+
#define UART_FIFO_TRIGGER_LEVEL_RX (24)
8387

8488
static mutex_t write_mutex_0;
8589
static mutex_t write_mutex_1;
@@ -111,12 +115,15 @@ typedef struct _machine_uart_obj_t {
111115
mutex_t *read_mutex;
112116
ringbuf_t write_buffer;
113117
mutex_t *write_mutex;
118+
uint16_t mp_irq_trigger; // user IRQ trigger mask
119+
uint16_t mp_irq_flags; // user IRQ active IRQ flags
120+
mp_irq_obj_t *mp_irq_obj; // user IRQ object
114121
} machine_uart_obj_t;
115122

116123
static machine_uart_obj_t machine_uart_obj[] = {
117124
{{&machine_uart_type}, uart0, 0, 0, DEFAULT_UART_BITS, UART_PARITY_NONE, DEFAULT_UART_STOP,
118125
MICROPY_HW_UART0_TX, MICROPY_HW_UART0_RX, MICROPY_HW_UART0_CTS, MICROPY_HW_UART0_RTS,
119-
0, 0, 0, 0, {NULL, 1, 0, 0}, &read_mutex_0, {NULL, 1, 0, 0}, &write_mutex_0},
126+
0, 0, 0, 0, {NULL, 1, 0, 0}, &read_mutex_0, {NULL, 1, 0, 0}, &write_mutex_0, 0, 0, NULL},
120127
{{&machine_uart_type}, uart1, 1, 0, DEFAULT_UART_BITS, UART_PARITY_NONE, DEFAULT_UART_STOP,
121128
MICROPY_HW_UART1_TX, MICROPY_HW_UART1_RX, MICROPY_HW_UART1_CTS, MICROPY_HW_UART1_RTS,
122129
0, 0, 0, 0, {NULL, 1, 0, 0}, &read_mutex_1, {NULL, 1, 0, 0}, &write_mutex_1},
@@ -144,14 +151,15 @@ static inline void read_mutex_unlock(machine_uart_obj_t *u) {
144151
mutex_exit(u->read_mutex);
145152
}
146153

147-
// take all bytes from the fifo and store them in the buffer
148-
static void uart_drain_rx_fifo(machine_uart_obj_t *self) {
154+
// take at most max_items bytes from the fifo and store them in the buffer
155+
static void uart_drain_rx_fifo(machine_uart_obj_t *self, uint32_t max_items) {
149156
if (read_mutex_try_lock(self)) {
150-
while (uart_is_readable(self->uart) && ringbuf_free(&self->read_buffer) > 0) {
157+
while (uart_is_readable(self->uart) && ringbuf_free(&self->read_buffer) > 0 && max_items > 0) {
151158
// Get a byte from uart and put into the buffer. Every entry from
152159
// the FIFO is accompanied by 4 error bits, that may be used for
153160
// error handling.
154161
uint16_t c = uart_get_hw(self->uart)->dr;
8000 162+
max_items -= 1;
155163
if (c & UART_UARTDR_OE_BITS) {
156164
// Overrun Error: We missed at least one byte. Not much we can do here.
157165
}
@@ -187,15 +195,30 @@ static void uart_fill_tx_fifo(machine_uart_obj_t *self) {
187195
}
188196

189197
static inline void uart_service_interrupt(machine_uart_obj_t *self) {
190-
if (uart_get_hw(self->uart)->mis & (UART_UARTMIS_RXMIS_BITS | UART_UARTMIS_RTMIS_BITS)) { // rx interrupt?
191-
// clear all interrupt bits but tx
192-
uart_get_hw(self->uart)->icr = UART_UARTICR_BITS & (~UART_UARTICR_TXIC_BITS);
193-
uart_drain_rx_fifo(self);
198+
uint16_t mp_irq_flags = uart_get_hw(self->uart)->mis & (UART_UARTMIS_RXMIS_BITS | UART_UARTMIS_RTMIS_BITS);
199+
if (mp_irq_flags) { // rx interrupt?
200+
// clear all interrupt bits but tx and break
201+
uart_get_hw(self->uart)->icr = UART_UARTICR_BITS & ~(UART_UARTICR_TXIC_BITS | UART_UARTICR_BEIC_BITS);
202+
uart_drain_rx_fifo(self, UART_FIFO_TRIGGER_LEVEL_RX - 1);
194203
}
195204
if (uart_get_hw(self->uart)->mis & UART_UARTMIS_TXMIS_BITS) { // tx interrupt?
196-
// clear all interrupt bits but rx
197-
uart_get_hw(self->uart)->icr = UART_UARTICR_BITS & ~(UART_UARTICR_RXIC_BITS | UART_UARTICR_RTIC_BITS);
198-
uart_fill_tx_fifo(self);
205+
// clear all interrupt bits but rx and break
206+
uart_get_hw(self->uart)->icr = UART_UARTICR_BITS & ~(UART_UARTICR_RXIC_BITS | UART_UARTICR_RTIC_BITS | UART_UARTICR_BEIC_BITS);
207+
if (ringbuf_avail(&self->write_buffer) == 0) {
208+
mp_irq_flags |= UART_UARTMIS_TXMIS_BITS;
209+
} else {
210+
uart_fill_tx_fifo(self);
211+
}
212+
}
213+
if (uart_get_hw(self->uart)->mis & UART_UARTMIS_BEMIS_BITS) { // break interrupt?
214+
// CLear the event
215+
hw_set_bits(&uart_get_hw(self->uart)->icr, UART_UARTICR_BEIC_BITS);
216+
mp_irq_flags |= UART_UARTMIS_BEMIS_BITS;
217+
}
218+
// Check the flags to see if the user handler should be called
219+
if (self->mp_irq_trigger & mp_irq_flags) {
220+
self->mp_irq_flags = mp_irq_flags;
221+
mp_irq_handler(self->mp_irq_obj);
199222
}
200223
}
201224

@@ -215,14 +238,17 @@ static void uart1_irq_handler(void) {
215238
{ MP_ROM_QSTR(MP_QSTR_INV_RX), MP_ROM_INT(UART_INVERT_RX) }, \
216239
{ MP_ROM_QSTR(MP_QSTR_CTS), MP_ROM_INT(UART_HWCONTROL_CTS) }, \
217240
{ MP_ROM_QSTR(MP_QSTR_RTS), MP_ROM_INT(UART_HWCONTROL_RTS) }, \
241+
{ MP_ROM_QSTR(MP_QSTR_IRQ_RXIDLE), MP_ROM_INT(UART_UARTMIS_RTMIS_BITS) }, \
242+
{ MP_ROM_QSTR(MP_QSTR_IRQ_TXIDLE), MP_ROM_INT(UART_UARTMIS_TXMIS_BITS) }, \
243+
{ MP_ROM_QSTR(MP_QSTR_IRQ_BREAK), MP_ROM_INT(UART_UARTMIS_BEMIS_BITS) }, \
218244

219245
static void mp_machine_uart_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
220246
machine_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
221247
mp_printf(print, "UART(%u, baudrate=%u, bits=%u, parity=%s, stop=%u, tx=%d, rx=%d, "
222-
"txbuf=%d, rxbuf=%d, timeout=%u, timeout_char=%u, invert=%s)",
248+
"txbuf=%d, rxbuf=%d, timeout=%u, timeout_char=%u, invert=%s, irq=%d)",
223249
self->uart_id, self->baudrate, self->bits, _parity_name[self->parity],
224250
self->stop, self->tx, self->rx, self->write_buffer.size - 1, self->read_buffer.size - 1,
225-
self->timeout, self->timeout_char, _invert_name[self->invert]);
251+
self->timeout, self->timeout_char, _invert_name[self->invert], self->mp_irq_trigger);
226252
}
227253

228254
static void mp_machine_uart_init_helper(machine_uart_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
@@ -441,11 +467,19 @@ static void mp_machine_uart_deinit(machine_uart_obj_t *self) {
441467
self->baudrate = 0;
442468
MP_STATE_PORT(rp2_uart_rx_buffer[self->uart_id]) = NULL;
443469
MP_STATE_PORT(rp2_uart_tx_buffer[self->uart_id]) = NULL;
470+
MP_STATE_PORT(rp2_uart_irq_obj)[self->uart_id] = NULL;
471+
self->mp_irq_obj = NULL;
472+
self->mp_irq_trigger = 0;
473+
}
474+
475+
void machine_uart_deinit_all() {
476+
mp_machine_uart_deinit((machine_uart_obj_t *)&machine_uart_obj[0]);
477+
mp_machine_uart_deinit((machine_uart_obj_t *)&machine_uart_obj[1]);
444478
}
445479

446480
static mp_int_t mp_machine_uart_any(machine_uart_obj_t *self) {
447481
// get all bytes from the fifo first
448-
uart_drain_rx_fifo(self);
482+
uart_drain_rx_fifo(self, UART_FIFO_SIZE_RX + 1);
449483
return ringbuf_avail(&self->read_buffer);
450484
}
451485

@@ -460,6 +494,77 @@ static void mp_machine_uart_sendbreak(machine_uart_obj_t *self) {
460494
uart_set_break(self->uart, false);
461495
}
462496

497+
static void uart_set_irq_level(machine_uart_obj_t *self, uint16_t trigger) {
498+
if (trigger & UART_UARTMIS_BEMIS_BITS) {
499+
// Enable the break Interrupt
500+
hw_set_bits(&uart_get_hw(self->uart)->imsc, UART_UARTIMSC_BEIM_BITS);
501+
} else {
502+
// Disable the break Interrupt
503+
hw_clear_bits(&uart_get_hw(self->uart)->imsc, UART_UARTIMSC_BEIM_BITS);
504+
}
505+
if (trigger & UART_UARTMIS_RTMIS_BITS) {
506+
// Set the RX trigger level to 3/4 FIFO_size
507+
hw_write_masked(&uart_get_hw(self->uart)->ifls, 0b011 << UART_UARTIFLS_RXIFLSEL_LSB,
508+
UART_UARTIFLS_RXIFLSEL_BITS);
509+
} else {
510+
// Set the RX trigger level to 1/8 FIFO_size
511+
hw_write_masked(&uart_get_hw(self->uart)->ifls, 0 << UART_UARTIFLS_RXIFLSEL_LSB,
512+
UART_UARTIFLS_RXIFLSEL_BITS);
513+
}
514+
}
515+
516+
static mp_uint_t uart_irq_trigger(mp_obj_t self_in, mp_uint_t new_trigger) {
517+
machine_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
518+
self->mp_irq_trigger = new_trigger;
519+
uart_set_irq_level(self, new_trigger);
520+
return 0;
521+
}
522+
523+
static mp_uint_t uart_irq_info(mp_obj_t self_in, mp_uint_t info_type) {
524+
machine_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
525+
if (info_type == MP_IRQ_INFO_FLAGS) {
526+
return self->mp_irq_flags;
527+
} else if (info_type == MP_IRQ_INFO_TRIGGERS) {
528+
return self->mp_irq_trigger;
529+
}
530+
return 0;
531+
}
532+
533+
static const mp_irq_methods_t uart_irq_methods = {
534+
.trigger = uart_irq_trigger,
535+
.info = uart_irq_info,
536+
};
537+
538+
static mp_irq_obj_t *mp_machine_uart_irq(machine_uart_obj_t *self, bool any_args, mp_arg_val_t *args) {
539+
if (self->mp_irq_obj == NULL) {
540+
self->mp_irq_trigger = 0;
541+
self->mp_irq_obj = mp_irq_new(&uart_irq_methods, MP_OBJ_FROM_PTR(self));
542+
MP_STATE_PORT(rp2_uart_irq_obj)[self->uart_id] = self->mp_irq_obj;
543+
}
544+
545+
if (any_args) {
546+
// Check the handler
547+
mp_obj_t handler = args[MP_IRQ_ARG_INIT_handler].u_obj;
548+
if (handler != mp_const_none && !mp_obj_is_callable(handler)) {
549+
mp_raise_ValueError(MP_ERROR_TEXT("handler must be None or callable"));
550+
}
551+
552+
// Check the trigger
553+
mp_uint_t trigger = args[MP_IRQ_ARG_INIT_trigger].u_int;
554+
mp_uint_t not_supported = trigger & ~MP_UART_ALLOWED_FLAGS;
555+
if (trigger != 0 && not_supported) {
556+
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("trigger 0x%04x unsupported"), not_supported);
557+
}
558+
559+
self->mp_irq_obj->handler = handler;
560+
self->mp_irq_obj->ishard = args[MP_IRQ_ARG_INIT_hard].u_bool;
561+
self->mp_irq_trigger = trigger;
562+
uart_set_irq_level(self, trigger);
563+
}
564+
565+
return self->mp_irq_obj;
566+
}
567+
463568
static mp_uint_t mp_machine_uart_read(mp_obj_t self_in, void *buf_in, mp_uint_t size, int *errcode) {
464569
machine_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
465570
mp_uint_t start = mp_hal_ticks_ms();
@@ -471,7 +576,7 @@ static mp_uint_t mp_machine_uart_read(mp_obj_t self_in, void *buf_in, mp_uint_t
471576
while (ringbuf_avail(&self->read_buffer) == 0) {
472577
if (uart_is_readable(self->uart)) {
473578
// Force a few incoming bytes to the buffer
474-
uart_drain_rx_fifo(self);
579+
uart_drain_rx_fifo(self, UART_FIFO_SIZE_RX + 1);
475580
break;
476581
}
477582
mp_uint_t elapsed = mp_hal_ticks_ms() - start;
@@ -572,3 +677,4 @@ static mp_uint_t mp_machine_uart_ioctl(mp_obj_t self_in, mp_uint_t request, uint
572677

573678
MP_REGISTER_ROOT_POINTER(void *rp2_uart_rx_buffer[2]);
574679
MP_REGISTER_ROOT_POINTER(void *rp2_uart_tx_buffer[2]);
680+
MP_REGISTER_ROOT_POINTER(void *rp2_uart_irq_obj[2]);

‎ports/rp2/main.c

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -224,6 +224,7 @@ int main(int argc, char **argv) {
224224
#endif
225225
machine_pwm_deinit_all();
226226
machine_pin_deinit();
227+
machine_uart_deinit_all();
227228
#if MICROPY_PY_THREAD
228229
mp_thread_deinit();
229230
#endif

‎ports/rp2/modmachine.h

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -8,6 +8,7 @@ void machine_pin_deinit(void);
88
void machine_i2s_init0(void);
99
void machine_i2s_deinit_all(void);
1010
void machine_pwm_deinit_all(void);
11+
void machine_uart_deinit_all(void);
1112

1213
struct _machine_spi_obj_t *spi_from_mp_obj(mp_obj_t o);
1314

‎ports/rp2/mpconfigport.h

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -146,6 +146,7 @@
146146
#define MICROPY_PY_MACHINE_UART (1)
147147
#define MICROPY_PY_MACHINE_UART_INCLUDEFILE "ports/rp2/machine_uart.c"
148148
#define MICROPY_PY_MACHINE_UART_SENDBREAK (1)
149+
#define MICROPY_PY_MACHINE_UART_IRQ (1)
149150
#define MICROPY_PY_MACHINE_WDT (1)
150151
#define MICROPY_PY_MACHINE_WDT_INCLUDEFILE "ports/rp2/machine_wdt.c"
151152
#define MICROPY_PY_MACHINE_FREQ_NUM_ARGS_MAX (2)

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