rp2/machine_uart: Add machine.UART init/deinit methods.

Without these methods a lot of existing "portable" scripts are broken.
This change improves portability by making rp2 machine.UART more compliant
with the documented machine UART interface.

ports/rp2/machine_uart.c

@@ -162,11 +162,10 @@ STATIC void machine_uart_print(const mp_print_t *print, mp_obj_t self_in, mp_pri
         self->timeout, self->timeout_char, _invert_name[self->invert]);
 }
 
-STATIC mp_obj_t machine_uart_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
-    enum { ARG_id, ARG_baudrate, ARG_bits, ARG_parity, ARG_stop, ARG_tx, ARG_rx, ARG_cts, ARG_rts,
+STATIC void machine_uart_init_helper(machine_uart_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_baudrate, ARG_bits, ARG_parity, ARG_stop, ARG_tx, ARG_rx, ARG_cts, ARG_rts,
            ARG_timeout, ARG_timeout_char, ARG_invert, ARG_flow, ARG_txbuf, ARG_rxbuf};
     static const mp_arg_t allowed_args[] = {
-        { MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
         { MP_QSTR_baudrate, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_bits, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_parity, MP_ARG_OBJ, {.u_rom_obj = MP_ROM_INT(-1)} },
@@ -185,16 +184,7 @@ STATIC mp_obj_t machine_uart_make_new(const mp_obj_type_t *type, size_t n_args,
 
     // Parse args.
     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);
-
-    // Get UART bus.
-    int uart_id = mp_obj_get_int(args[ARG_id].u_obj);
-    if (uart_id < 0 || uart_id >= MP_ARRAY_SIZE(machine_uart_obj)) {
-        mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("UART(%d) doesn't exist"), uart_id);
-    }
-
-    // Get static peripheral object.
-    machine_uart_obj_t *self = (machine_uart_obj_t *)&machine_uart_obj[uart_id];
+    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
 
     // Set baudrate if configured.
     if (args[ARG_baudrate].u_int > 0) {
@@ -305,7 +295,7 @@ STATIC mp_obj_t machine_uart_make_new(const mp_obj_type_t *type, size_t n_args,
     }
 
     // Initialise the UART peripheral if any arguments given, or it was not initialised previously.
-    if (n_args > 1 || n_kw > 0 || self->baudrate == 0) {
+    if (n_args > 0 || kw_args->used > 0 || self->baudrate == 0) {
         if (self->baudrate == 0) {
             self->baudrate = DEFAULT_UART_BAUDRATE;
         }
@@ -339,10 +329,10 @@ STATIC mp_obj_t machine_uart_make_new(const mp_obj_type_t *type, size_t n_args,
 
         // Allocate the RX/TX buffers.
         ringbuf_alloc(&(self->read_buffer), rxbuf_len + 1);
-        MP_STATE_PORT(rp2_uart_rx_buffer[uart_id]) = self->read_buffer.buf;
+        MP_STATE_PORT(rp2_uart_rx_buffer[self->uart_id]) = self->read_buffer.buf;
 
         ringbuf_alloc(&(self->write_buffer), txbuf_len + 1);
-        MP_STATE_PORT(rp2_uart_tx_buffer[uart_id]) = self->write_buffer.buf;
+        MP_STATE_PORT(rp2_uart_tx_buffer[self->uart_id]) = self->write_buffer.buf;
 
         // Set the irq handler.
         if (self->uart_id == 0) {
@@ -356,10 +346,50 @@ STATIC mp_obj_t machine_uart_make_new(const mp_obj_type_t *type, size_t n_args,
         // Enable the uart irq; this macro sets the rx irq level to 4.
         uart_set_irq_enables(self->uart, true, true);
     }
+}
+
+STATIC mp_obj_t machine_uart_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, 1, MP_OBJ_FUN_ARGS_MAX, true);
+
+    // Get UART bus.
+    int uart_id = mp_obj_get_int(args[0]);
+    if (uart_id < 0 || uart_id >= MP_ARRAY_SIZE(machine_uart_obj)) {
+        mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("UART(%d) doesn't exist"), uart_id);
+    }
+
+    // Get static peripheral object.
+    machine_uart_obj_t *self = (machine_uart_obj_t *)&machine_uart_obj[uart_id];
+
+    // Initialise the UART peripheral.
+    mp_map_t kw_args;
+    mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
+    machine_uart_init_helper(self, n_args - 1, args + 1, &kw_args);
 
     return MP_OBJ_FROM_PTR(self);
 }
 
+STATIC mp_obj_t machine_uart_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    // Initialise the UART peripheral.
+    machine_uart_init_helper(args[0], n_args - 1, args + 1, kw_args);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(machine_uart_init_obj, 1, machine_uart_init);
+
+STATIC mp_obj_t machine_uart_deinit(mp_obj_t self_in) {
+    machine_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    uart_deinit(self->uart);
+    if (self->uart_id == 0) {
+        irq_set_enabled(UART0_IRQ, false);
+    } else {
+        irq_set_enabled(UART1_IRQ, false);
+    }
+    self->baudrate = 0;
+    MP_STATE_PORT(rp2_uart_rx_buffer[self->uart_id]) = NULL;
+    MP_STATE_PORT(rp2_uart_tx_buffer[self->uart_id]) = NULL;
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_uart_deinit_obj, machine_uart_deinit);
+
 STATIC mp_obj_t machine_uart_any(mp_obj_t self_in) {
     machine_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
     // get all bytes from the fifo first
@@ -380,8 +410,10 @@ STATIC mp_obj_t machine_uart_sendbreak(mp_obj_t self_in) {
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_uart_sendbreak_obj, machine_uart_sendbreak);
 
 STATIC const mp_rom_map_elem_t machine_uart_locals_dict_table[] = {
-    { MP_ROM_QSTR(MP_QSTR_any), MP_ROM_PTR(&machine_uart_any_obj) },
+    { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&machine_uart_init_obj) },
+    { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&machine_uart_deinit_obj) },
 
+    { MP_ROM_QSTR(MP_QSTR_any), MP_ROM_PTR(&machine_uart_any_obj) },
     { MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
     { MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
     { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },