uart.c 33.6 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013, 2014 Damien P. George
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

27
28
#include <stdio.h>
#include <string.h>
29
#include <stdarg.h>
30

31
32
33
#include "py/nlr.h"
#include "py/runtime.h"
#include "py/stream.h"
34
#include "py/mperrno.h"
35
#include "py/mphal.h"
Damien George's avatar
Damien George committed
36
#include "uart.h"
37
#include "irq.h"
38
#include "genhdr/pins.h"
39

40
41
42
43
/// \moduleref pyb
/// \class UART - duplex serial communication bus
///
/// UART implements the standard UART/USART duplex serial communications protocol.  At
44
45
46
/// the physical level it consists of 2 lines: RX and TX.  The unit of communication
/// is a character (not to be confused with a string character) which can be 8 or 9
/// bits wide.
47
///
48
/// UART objects can be created and initialised using:
49
50
51
52
///
///     from pyb import UART
///
///     uart = UART(1, 9600)                         # init with given baudrate
53
///     uart.init(9600, bits=8, parity=None, stop=1) # init with given parameters
54
///
55
/// Bits can be 8 or 9.  Parity can be None, 0 (even) or 1 (odd).  Stop can be 1 or 2.
56
///
57
58
59
60
/// A UART object acts like a stream object and reading and writing is done
/// using the standard stream methods:
///
///     uart.read(10)       # read 10 characters, returns a bytes object
61
///     uart.read()         # read all available characters
62
63
64
65
66
67
68
69
70
71
///     uart.readline()     # read a line
///     uart.readinto(buf)  # read and store into the given buffer
///     uart.write('abc')   # write the 3 characters
///
/// Individual characters can be read/written using:
///
///     uart.readchar()     # read 1 character and returns it as an integer
///     uart.writechar(42)  # write 1 character
///
/// To check if there is anything to be read, use:
72
73
///
///     uart.any()               # returns True if any characters waiting
74

75
76
77
#define CHAR_WIDTH_8BIT (0)
#define CHAR_WIDTH_9BIT (1)

Damien George's avatar
Damien George committed
78
struct _pyb_uart_obj_t {
Dave Hylands's avatar
Dave Hylands committed
79
    mp_obj_base_t base;
80
    UART_HandleTypeDef uart;            // this is 17 words big
81
    IRQn_Type irqn;
82
83
84
85
    pyb_uart_t uart_id : 8;
    bool is_enabled : 1;
    byte char_width;                    // 0 for 7,8 bit chars, 1 for 9 bit chars
    uint16_t char_mask;                 // 0x7f for 7 bit, 0xff for 8 bit, 0x1ff for 9 bit
86
87
88
89
90
91
    uint16_t timeout;                   // timeout waiting for first char
    uint16_t timeout_char;              // timeout waiting between chars
    uint16_t read_buf_len;              // len in chars; buf can hold len-1 chars
    volatile uint16_t read_buf_head;    // indexes first empty slot
    uint16_t read_buf_tail;             // indexes first full slot (not full if equals head)
    byte *read_buf;                     // byte or uint16_t, depending on char size
Dave Hylands's avatar
Dave Hylands committed
92
};
93

94
95
96
STATIC mp_obj_t pyb_uart_deinit(mp_obj_t self_in);

void uart_init0(void) {
97
98
    for (int i = 0; i < MP_ARRAY_SIZE(MP_STATE_PORT(pyb_uart_obj_all)); i++) {
        MP_STATE_PORT(pyb_uart_obj_all)[i] = NULL;
99
100
101
102
103
    }
}

// unregister all interrupt sources
void uart_deinit(void) {
104
105
    for (int i = 0; i < MP_ARRAY_SIZE(MP_STATE_PORT(pyb_uart_obj_all)); i++) {
        pyb_uart_obj_t *uart_obj = MP_STATE_PORT(pyb_uart_obj_all)[i];
106
107
108
109
110
111
        if (uart_obj != NULL) {
            pyb_uart_deinit(uart_obj);
        }
    }
}

112
// assumes Init parameters have been set up correctly
113
STATIC bool uart_init2(pyb_uart_obj_t *uart_obj) {
114
115
    USART_TypeDef *UARTx;
    IRQn_Type irqn;
116
    int uart_unit;
117

118
    const pin_obj_t *pins[4] = {0};
119

120
121
    switch (uart_obj->uart_id) {
        #if defined(MICROPY_HW_UART1_TX) && defined(MICROPY_HW_UART1_RX)
122
        case PYB_UART_1:
123
            uart_unit = 1;
124
125
            UARTx = USART1;
            irqn = USART1_IRQn;
126
127
            pins[0] = &MICROPY_HW_UART1_TX;
            pins[1] = &MICROPY_HW_UART1_RX;
128
129
130
131
            __USART1_CLK_ENABLE();
            break;
        #endif

132
        #if defined(MICROPY_HW_UART2_TX) && defined(MICROPY_HW_UART2_RX)
Damien George's avatar
Damien George committed
133
        case PYB_UART_2:
134
            uart_unit = 2;
Damien George's avatar
Damien George committed
135
            UARTx = USART2;
136
            irqn = USART2_IRQn;
137
138
            pins[0] = &MICROPY_HW_UART2_TX;
            pins[1] = &MICROPY_HW_UART2_RX;
139
            #if defined(MICROPY_HW_UART2_RTS)
140
            if (uart_obj->uart.Init.HwFlowCtl & UART_HWCONTROL_RTS) {
141
                pins[2] = &MICROPY_HW_UART2_RTS;
142
            }
143
144
            #endif
            #if defined(MICROPY_HW_UART2_CTS)
145
            if (uart_obj->uart.Init.HwFlowCtl & UART_HWCONTROL_CTS) {
146
                pins[3] = &MICROPY_HW_UART2_CTS;
147
            }
148
            #endif
149
150
            __USART2_CLK_ENABLE();
            break;
151
        #endif
152

153
        #if defined(MICROPY_HW_UART3_TX) && defined(MICROPY_HW_UART3_RX)
Damien George's avatar
Damien George committed
154
        case PYB_UART_3:
155
            uart_unit = 3;
Damien George's avatar
Damien George committed
156
            UARTx = USART3;
157
            irqn = USART3_IRQn;
158
159
            pins[0] = &MICROPY_HW_UART3_TX;
            pins[1] = &MICROPY_HW_UART3_RX;
160
            #if defined(MICROPY_HW_UART3_RTS)
161
            if (uart_obj->uart.Init.HwFlowCtl & UART_HWCONTROL_RTS) {
162
                pins[2] = &MICROPY_HW_UART3_RTS;
163
            }
164
165
            #endif
            #if defined(MICROPY_HW_UART3_CTS)
166
            if (uart_obj->uart.Init.HwFlowCtl & UART_HWCONTROL_CTS) {
167
                pins[3] = &MICROPY_HW_UART3_CTS;
168
            }
169
            #endif
170
171
            __USART3_CLK_ENABLE();
            break;
172
        #endif
173

174
        #if defined(MICROPY_HW_UART4_TX) && defined(MICROPY_HW_UART4_RX)
Damien George's avatar
Damien George committed
175
        case PYB_UART_4:
176
            uart_unit = 4;
Damien George's avatar
Damien George committed
177
            UARTx = UART4;
178
            irqn = UART4_IRQn;
179
180
            pins[0] = &MICROPY_HW_UART4_TX;
            pins[1] = &MICROPY_HW_UART4_RX;
181
182
            __UART4_CLK_ENABLE();
            break;
183
        #endif
184

185
        #if defined(MICROPY_HW_UART5_TX) && defined(MICROPY_HW_UART5_RX)
Dave Hylands's avatar
Dave Hylands committed
186
        case PYB_UART_5:
187
            uart_unit = 5;
Dave Hylands's avatar
Dave Hylands committed
188
189
            UARTx = UART5;
            irqn = UART5_IRQn;
190
191
            pins[0] = &MICROPY_HW_UART5_TX;
            pins[1] = &MICROPY_HW_UART5_RX;
Dave Hylands's avatar
Dave Hylands committed
192
193
194
195
            __UART5_CLK_ENABLE();
            break;
        #endif

196
        #if defined(MICROPY_HW_UART6_TX) && defined(MICROPY_HW_UART6_RX)
Damien George's avatar
Damien George committed
197
        case PYB_UART_6:
198
            uart_unit = 6;
Damien George's avatar
Damien George committed
199
            UARTx = USART6;
200
            irqn = USART6_IRQn;
201
202
            pins[0] = &MICROPY_HW_UART6_TX;
            pins[1] = &MICROPY_HW_UART6_RX;
203
204
            __USART6_CLK_ENABLE();
            break;
205
        #endif
206

207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
        #if defined(MICROPY_HW_UART7_TX) && defined(MICROPY_HW_UART7_RX)
        case PYB_UART_7:
            uart_unit = 7;
            UARTx = UART7;
            irqn = UART7_IRQn;
            pins[0] = &MICROPY_HW_UART7_TX;
            pins[1] = &MICROPY_HW_UART7_RX;
            __UART7_CLK_ENABLE();
            break;
        #endif

        #if defined(MICROPY_HW_UART8_TX) && defined(MICROPY_HW_UART8_RX)
        case PYB_UART_8:
            uart_unit = 8;
            UARTx = UART8;
            irqn = UART8_IRQn;
            pins[0] = &MICROPY_HW_UART8_TX;
            pins[1] = &MICROPY_HW_UART8_RX;
            __UART8_CLK_ENABLE();
            break;
        #endif

229
        default:
230
            // UART does not exist or is not configured for this board
231
            return false;
232
233
    }

234
235
    uint32_t mode = MP_HAL_PIN_MODE_ALT;
    uint32_t pull = MP_HAL_PIN_PULL_UP;
236

237
238
239
240
241
242
243
    for (uint i = 0; i < 4; i++) {
        if (pins[i] != NULL) {
            bool ret = mp_hal_pin_config_alt(pins[i], mode, pull, AF_FN_UART, uart_unit);
            if (!ret) {
                return false;
            }
        }
244
245
    }

246
247
248
    uart_obj->irqn = irqn;
    uart_obj->uart.Instance = UARTx;

Damien George's avatar
Damien George committed
249
250
    // init UARTx
    HAL_UART_Init(&uart_obj->uart);
251

Damien George's avatar
Damien George committed
252
    uart_obj->is_enabled = true;
253
254
255
256

    return true;
}

257
/* obsolete and unused
Damien George's avatar
Damien George committed
258
259
bool uart_init(pyb_uart_obj_t *uart_obj, uint32_t baudrate) {
    UART_HandleTypeDef *uh = &uart_obj->uart;
Dave Hylands's avatar
Dave Hylands committed
260
261
    memset(uh, 0, sizeof(*uh));
    uh->Init.BaudRate = baudrate;
262
263
264
265
    uh->Init.WordLength = UART_WORDLENGTH_8B;
    uh->Init.StopBits = UART_STOPBITS_1;
    uh->Init.Parity = UART_PARITY_NONE;
    uh->Init.Mode = UART_MODE_TX_RX;
Dave Hylands's avatar
Dave Hylands committed
266
267
    uh->Init.HwFlowCtl = UART_HWCONTROL_NONE;
    uh->Init.OverSampling = UART_OVERSAMPLING_16;
Damien George's avatar
Damien George committed
268
    return uart_init2(uart_obj);
269
}
270
*/
271

272
273
274
275
276
277
278
279
280
mp_uint_t uart_rx_any(pyb_uart_obj_t *self) {
    int buffer_bytes = self->read_buf_head - self->read_buf_tail;
    if (buffer_bytes < 0) {
        return buffer_bytes + self->read_buf_len;
    } else if (buffer_bytes > 0) {
        return buffer_bytes;
    } else {
        return __HAL_UART_GET_FLAG(&self->uart, UART_FLAG_RXNE) != RESET;
    }
281
282
}

283
284
285
286
287
288
289
290
291
292
293
294
295
296
// Waits at most timeout milliseconds for at least 1 char to become ready for
// reading (from buf or for direct reading).
// Returns true if something available, false if not.
STATIC bool uart_rx_wait(pyb_uart_obj_t *self, uint32_t timeout) {
    uint32_t start = HAL_GetTick();
    for (;;) {
        if (self->read_buf_tail != self->read_buf_head || __HAL_UART_GET_FLAG(&self->uart, UART_FLAG_RXNE) != RESET) {
            return true; // have at least 1 char ready for reading
        }
        if (HAL_GetTick() - start >= timeout) {
            return false; // timeout
        }
        __WFI();
    }
297
298
}

299
300
301
302
303
304
305
306
307
308
309
// assumes there is a character available
int uart_rx_char(pyb_uart_obj_t *self) {
    if (self->read_buf_tail != self->read_buf_head) {
        // buffering via IRQ
        int data;
        if (self->char_width == CHAR_WIDTH_9BIT) {
            data = ((uint16_t*)self->read_buf)[self->read_buf_tail];
        } else {
            data = self->read_buf[self->read_buf_tail];
        }
        self->read_buf_tail = (self->read_buf_tail + 1) % self->read_buf_len;
310
311
312
313
        if (__HAL_UART_GET_FLAG(&self->uart, UART_FLAG_RXNE) != RESET) {
            // UART was stalled by flow ctrl: re-enable IRQ now we have room in buffer
            __HAL_UART_ENABLE_IT(&self->uart, UART_IT_RXNE);
        }
314
315
316
        return data;
    } else {
        // no buffering
317
        #if defined(MCU_SERIES_F7) || defined(MCU_SERIES_L4)
318
319
        return self->uart.Instance->RDR & self->char_mask;
        #else
320
        return self->uart.Instance->DR & self->char_mask;
321
        #endif
322
323
324
    }
}

325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
// Waits at most timeout milliseconds for TX register to become empty.
// Returns true if can write, false if can't.
STATIC bool uart_tx_wait(pyb_uart_obj_t *self, uint32_t timeout) {
    uint32_t start = HAL_GetTick();
    for (;;) {
        if (__HAL_UART_GET_FLAG(&self->uart, UART_FLAG_TXE)) {
            return true; // tx register is empty
        }
        if (HAL_GetTick() - start >= timeout) {
            return false; // timeout
        }
        __WFI();
    }
}

STATIC HAL_StatusTypeDef uart_tx_data(pyb_uart_obj_t *self, uint8_t *data, uint16_t len) {
341
342
343
344
345
    if (self->uart.Init.HwFlowCtl & UART_HWCONTROL_CTS) {
        // CTS can hold off transmission for an arbitrarily long time. Apply
        // the overall timeout rather than the character timeout.
        return HAL_UART_Transmit(&self->uart, data, len, self->timeout);
    }
346
347
348
349
350
351
352
353
    // The timeout specified here is for waiting for the TX data register to
    // become empty (ie between chars), as well as for the final char to be
    // completely transferred.  The default value for timeout_char is long
    // enough for 1 char, but we need to double it to wait for the last char
    // to be transferred to the data register, and then to be transmitted.
    return HAL_UART_Transmit(&self->uart, data, len, 2 * self->timeout_char);
}

354
STATIC void uart_tx_char(pyb_uart_obj_t *uart_obj, int c) {
355
    uint8_t ch = c;
356
    uart_tx_data(uart_obj, &ch, 1);
357
358
}

Damien George's avatar
Damien George committed
359
void uart_tx_strn(pyb_uart_obj_t *uart_obj, const char *str, uint len) {
360
    uart_tx_data(uart_obj, (uint8_t*)str, len);
361
362
}

Damien George's avatar
Damien George committed
363
void uart_tx_strn_cooked(pyb_uart_obj_t *uart_obj, const char *str, uint len) {
364
365
    for (const char *top = str + len; str < top; str++) {
        if (*str == '\n') {
Damien George's avatar
Damien George committed
366
            uart_tx_char(uart_obj, '\r');
367
        }
Damien George's avatar
Damien George committed
368
        uart_tx_char(uart_obj, *str);
369
370
371
    }
}

372
373
374
// this IRQ handler is set up to handle RXNE interrupts only
void uart_irq_handler(mp_uint_t uart_id) {
    // get the uart object
375
    pyb_uart_obj_t *self = MP_STATE_PORT(pyb_uart_obj_all)[uart_id - 1];
376
377
378
379
380
381
382
383
384
385
386

    if (self == NULL) {
        // UART object has not been set, so we can't do anything, not
        // even disable the IRQ.  This should never happen.
        return;
    }

    if (__HAL_UART_GET_FLAG(&self->uart, UART_FLAG_RXNE) != RESET) {
        if (self->read_buf_len != 0) {
            uint16_t next_head = (self->read_buf_head + 1) % self->read_buf_len;
            if (next_head != self->read_buf_tail) {
387
                // only read data if room in buf
388
                #if defined(MCU_SERIES_F7) || defined(MCU_SERIES_L4)
389
390
391
392
393
                int data = self->uart.Instance->RDR; // clears UART_FLAG_RXNE
                #else
                int data = self->uart.Instance->DR; // clears UART_FLAG_RXNE
                #endif
                data &= self->char_mask;
394
395
396
397
398
399
                if (self->char_width == CHAR_WIDTH_9BIT) {
                    ((uint16_t*)self->read_buf)[self->read_buf_head] = data;
                } else {
                    self->read_buf[self->read_buf_head] = data;
                }
                self->read_buf_head = next_head;
400
401
            } else { // No room: leave char in buf, disable interrupt
                __HAL_UART_DISABLE_IT(&self->uart, UART_IT_RXNE);
402
403
404
405
406
            }
        }
    }
}

407
408
409
/******************************************************************************/
/* Micro Python bindings                                                      */

410
STATIC void pyb_uart_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
Damien George's avatar
Damien George committed
411
    pyb_uart_obj_t *self = self_in;
412
    if (!self->is_enabled) {
413
        mp_printf(print, "UART(%u)", self->uart_id);
414
    } else {
415
416
417
418
        mp_int_t bits = (self->uart.Init.WordLength == UART_WORDLENGTH_8B ? 8 : 9);
        if (self->uart.Init.Parity != UART_PARITY_NONE) {
            bits -= 1;
        }
419
        mp_printf(print, "UART(%u, baudrate=%u, bits=%u, parity=",
420
            self->uart_id, self->uart.Init.BaudRate, bits);
421
        if (self->uart.Init.Parity == UART_PARITY_NONE) {
422
            mp_print_str(print, "None");
423
        } else {
424
            mp_printf(print, "%u", self->uart.Init.Parity == UART_PARITY_EVEN ? 0 : 1);
425
        }
426
427
428
429
430
431
432
433
434
        if (self->uart.Init.HwFlowCtl) {
            mp_printf(print, ", flow=");
            if (self->uart.Init.HwFlowCtl & UART_HWCONTROL_RTS) {
                mp_printf(print, "RTS%s", self->uart.Init.HwFlowCtl & UART_HWCONTROL_CTS ? "|" : "");
            }
            if (self->uart.Init.HwFlowCtl & UART_HWCONTROL_CTS) {
                mp_printf(print, "CTS");
            }
        }
435
        mp_printf(print, ", stop=%u, timeout=%u, timeout_char=%u, read_buf_len=%u)",
436
            self->uart.Init.StopBits == UART_STOPBITS_1 ? 1 : 2,
437
438
            self->timeout, self->timeout_char,
            self->read_buf_len == 0 ? 0 : self->read_buf_len - 1); // -1 to adjust for usable length of buffer
439
    }
440
441
}

442
/// \method init(baudrate, bits=8, parity=None, stop=1, *, timeout=1000, timeout_char=0, flow=0, read_buf_len=64)
443
///
444
/// Initialise the UART bus with the given parameters:
445
446
///
///   - `baudrate` is the clock rate.
447
///   - `bits` is the number of bits per byte, 7, 8 or 9.
448
///   - `parity` is the parity, `None`, 0 (even) or 1 (odd).
449
450
451
///   - `stop` is the number of stop bits, 1 or 2.
///   - `timeout` is the timeout in milliseconds to wait for the first character.
///   - `timeout_char` is the timeout in milliseconds to wait between characters.
452
///   - `flow` is RTS | CTS where RTS == 256, CTS == 512
453
454
455
456
457
458
459
///   - `read_buf_len` is the character length of the read buffer (0 to disable).
STATIC mp_obj_t pyb_uart_init_helper(pyb_uart_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
    static const mp_arg_t allowed_args[] = {
        { MP_QSTR_baudrate, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 9600} },
        { MP_QSTR_bits, MP_ARG_INT, {.u_int = 8} },
        { MP_QSTR_parity, MP_ARG_OBJ, {.u_obj = mp_const_none} },
        { MP_QSTR_stop, MP_ARG_INT, {.u_int = 1} },
460
        { MP_QSTR_flow, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = UART_HWCONTROL_NONE} },
461
462
463
464
        { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1000} },
        { MP_QSTR_timeout_char, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
        { MP_QSTR_read_buf_len, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 64} },
    };
465
466

    // parse args
467
468
469
470
471
    struct {
        mp_arg_val_t baudrate, bits, parity, stop, flow, timeout, timeout_char, read_buf_len;
    } args;
    mp_arg_parse_all(n_args, pos_args, kw_args,
        MP_ARRAY_SIZE(allowed_args), allowed_args, (mp_arg_val_t*)&args);
472

Damien George's avatar
Damien George committed
473
    // set the UART configuration values
474
475
    memset(&self->uart, 0, sizeof(self->uart));
    UART_InitTypeDef *init = &self->uart.Init;
476
477

    // baudrate
478
    init->BaudRate = args.baudrate.u_int;
479
480

    // parity
481
482
    mp_int_t bits = args.bits.u_int;
    if (args.parity.u_obj == mp_const_none) {
483
484
        init->Parity = UART_PARITY_NONE;
    } else {
485
        mp_int_t parity = mp_obj_get_int(args.parity.u_obj);
486
        init->Parity = (parity & 1) ? UART_PARITY_ODD : UART_PARITY_EVEN;
487
        bits += 1; // STs convention has bits including parity
488
    }
489
490
491
492
493
494
495
496
497
498
499

    // number of bits
    if (bits == 8) {
        init->WordLength = UART_WORDLENGTH_8B;
    } else if (bits == 9) {
        init->WordLength = UART_WORDLENGTH_9B;
    } else {
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "unsupported combination of bits and parity"));
    }

    // stop bits
500
    switch (args.stop.u_int) {
501
502
503
        case 1: init->StopBits = UART_STOPBITS_1; break;
        default: init->StopBits = UART_STOPBITS_2; break;
    }
504
505

    // flow control
506
    init->HwFlowCtl = args.flow.u_int;
507
508
509

    // extra config (not yet configurable)
    init->Mode = UART_MODE_TX_RX;
510
511
    init->OverSampling = UART_OVERSAMPLING_16;

Damien George's avatar
Damien George committed
512
513
    // init UART (if it fails, it's because the port doesn't exist)
    if (!uart_init2(self)) {
514
515
516
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "UART(%d) does not exist", self->uart_id));
    }

517
    // set timeout
518
    self->timeout = args.timeout.u_int;
519
520
521

    // set timeout_char
    // make sure it is at least as long as a whole character (13 bits to be safe)
522
    self->timeout_char = args.timeout_char.u_int;
523
524
525
526
    uint32_t min_timeout_char = 13000 / init->BaudRate + 1;
    if (self->timeout_char < min_timeout_char) {
        self->timeout_char = min_timeout_char;
    }
527
528
529
530

    // setup the read buffer
    m_del(byte, self->read_buf, self->read_buf_len << self->char_width);
    if (init->WordLength == UART_WORDLENGTH_9B && init->Parity == UART_PARITY_NONE) {
531
        self->char_mask = 0x1ff;
532
533
        self->char_width = CHAR_WIDTH_9BIT;
    } else {
534
535
536
537
538
        if (init->WordLength == UART_WORDLENGTH_9B || init->Parity == UART_PARITY_NONE) {
            self->char_mask = 0xff;
        } else {
            self->char_mask = 0x7f;
        }
539
540
541
542
        self->char_width = CHAR_WIDTH_8BIT;
    }
    self->read_buf_head = 0;
    self->read_buf_tail = 0;
543
    if (args.read_buf_len.u_int <= 0) {
544
545
546
547
548
549
550
        // no read buffer
        self->read_buf_len = 0;
        self->read_buf = NULL;
        HAL_NVIC_DisableIRQ(self->irqn);
        __HAL_UART_DISABLE_IT(&self->uart, UART_IT_RXNE);
    } else {
        // read buffer using interrupts
551
        self->read_buf_len = args.read_buf_len.u_int + 1; // +1 to adjust for usable length of buffer
552
        self->read_buf = m_new(byte, self->read_buf_len << self->char_width);
553
        __HAL_UART_ENABLE_IT(&self->uart, UART_IT_RXNE);
554
        HAL_NVIC_SetPriority(self->irqn, IRQ_PRI_UART, IRQ_SUBPRI_UART); 
555
        HAL_NVIC_EnableIRQ(self->irqn);
556
557
    }

558
559
    // compute actual baudrate that was configured
    // (this formula assumes UART_OVERSAMPLING_16)
560
561
562
563
564
565
566
567
568
569
570
571
572
    uint32_t actual_baudrate = 0;
    #if defined(MCU_SERIES_F7)
    UART_ClockSourceTypeDef clocksource = UART_CLOCKSOURCE_UNDEFINED;
    UART_GETCLOCKSOURCE(&self->uart, clocksource);
    switch (clocksource) {
        case UART_CLOCKSOURCE_PCLK1:  actual_baudrate = HAL_RCC_GetPCLK1Freq(); break;
        case UART_CLOCKSOURCE_PCLK2:  actual_baudrate = HAL_RCC_GetPCLK2Freq(); break;
        case UART_CLOCKSOURCE_HSI:    actual_baudrate = HSI_VALUE; break;
        case UART_CLOCKSOURCE_SYSCLK: actual_baudrate = HAL_RCC_GetSysClockFreq(); break;
        case UART_CLOCKSOURCE_LSE:    actual_baudrate = LSE_VALUE; break;
        case UART_CLOCKSOURCE_UNDEFINED: break;
    }
    #else
573
574
575
576
577
    if (self->uart.Instance == USART1
        #if defined(USART6)
        || self->uart.Instance == USART6
        #endif
        ) {
578
579
580
581
        actual_baudrate = HAL_RCC_GetPCLK2Freq();
    } else {
        actual_baudrate = HAL_RCC_GetPCLK1Freq();
    }
582
    #endif
583
584
585
586
587
588
589
590
591
592
593
594
595
596
    actual_baudrate /= self->uart.Instance->BRR;

    // check we could set the baudrate within 5%
    uint32_t baudrate_diff;
    if (actual_baudrate > init->BaudRate) {
        baudrate_diff = actual_baudrate - init->BaudRate;
    } else {
        baudrate_diff = init->BaudRate - actual_baudrate;
    }
    init->BaudRate = actual_baudrate; // remember actual baudrate for printing
    if (20 * baudrate_diff > init->BaudRate) {
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "set baudrate %d is not within 5%% of desired value", actual_baudrate));
    }

597
598
599
    return mp_const_none;
}

600
601
602
603
604
605
606
/// \classmethod \constructor(bus, ...)
///
/// Construct a UART object on the given bus.  `bus` can be 1-6, or 'XA', 'XB', 'YA', or 'YB'.
/// With no additional parameters, the UART object is created but not
/// initialised (it has the settings from the last initialisation of
/// the bus, if any).  If extra arguments are given, the bus is initialised.
/// See `init` for parameters of initialisation.
607
608
609
610
611
612
613
614
///
/// The physical pins of the UART busses are:
///
///   - `UART(4)` is on `XA`: `(TX, RX) = (X1, X2) = (PA0, PA1)`
///   - `UART(1)` is on `XB`: `(TX, RX) = (X9, X10) = (PB6, PB7)`
///   - `UART(6)` is on `YA`: `(TX, RX) = (Y1, Y2) = (PC6, PC7)`
///   - `UART(3)` is on `YB`: `(TX, RX) = (Y9, Y10) = (PB10, PB11)`
///   - `UART(2)` is on: `(TX, RX) = (X3, X4) = (PA2, PA3)`
615
STATIC mp_obj_t pyb_uart_make_new(const mp_obj_type_t *type, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
616
617
618
    // check arguments
    mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);

619
    // work out port
620
    int uart_id = 0;
621
622
    if (MP_OBJ_IS_STR(args[0])) {
        const char *port = mp_obj_str_get_str(args[0]);
623
        if (0) {
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
        #ifdef MICROPY_HW_UART1_NAME
        } else if (strcmp(port, MICROPY_HW_UART1_NAME) == 0) {
            uart_id = PYB_UART_1;
        #endif
        #ifdef MICROPY_HW_UART2_NAME
        } else if (strcmp(port, MICROPY_HW_UART2_NAME) == 0) {
            uart_id = PYB_UART_2;
        #endif
        #ifdef MICROPY_HW_UART3_NAME
        } else if (strcmp(port, MICROPY_HW_UART3_NAME) == 0) {
            uart_id = PYB_UART_3;
        #endif
        #ifdef MICROPY_HW_UART4_NAME
        } else if (strcmp(port, MICROPY_HW_UART4_NAME) == 0) {
            uart_id = PYB_UART_4;
        #endif
        #ifdef MICROPY_HW_UART5_NAME
        } else if (strcmp(port, MICROPY_HW_UART5_NAME) == 0) {
            uart_id = PYB_UART_5;
        #endif
        #ifdef MICROPY_HW_UART6_NAME
        } else if (strcmp(port, MICROPY_HW_UART6_NAME) == 0) {
            uart_id = PYB_UART_6;
        #endif
648
        } else {
649
            nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "UART(%s) does not exist", port));
650
        }
651
    } else {
652
        uart_id = mp_obj_get_int(args[0]);
653
        if (uart_id < 1 || uart_id > MP_ARRAY_SIZE(MP_STATE_PORT(pyb_uart_obj_all))) {
654
655
656
657
658
            nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "UART(%d) does not exist", uart_id));
        }
    }

    pyb_uart_obj_t *self;
659
    if (MP_STATE_PORT(pyb_uart_obj_all)[uart_id - 1] == NULL) {
660
661
662
663
        // create new UART object
        self = m_new0(pyb_uart_obj_t, 1);
        self->base.type = &pyb_uart_type;
        self->uart_id = uart_id;
664
        MP_STATE_PORT(pyb_uart_obj_all)[uart_id - 1] = self;
665
666
    } else {
        // reference existing UART object
667
        self = MP_STATE_PORT(pyb_uart_obj_all)[uart_id - 1];
668
669
    }

670
671
672
673
    if (n_args > 1 || n_kw > 0) {
        // start the peripheral
        mp_map_t kw_args;
        mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
674
        pyb_uart_init_helper(self, n_args - 1, args + 1, &kw_args);
675
676
    }

677
    return self;
678
679
}

680
STATIC mp_obj_t pyb_uart_init(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
Damien George's avatar
Damien George committed
681
    return pyb_uart_init_helper(args[0], n_args - 1, args + 1, kw_args);
682
}
Damien George's avatar
Damien George committed
683
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_uart_init_obj, 1, pyb_uart_init);
684

685
686
/// \method deinit()
/// Turn off the UART bus.
Damien George's avatar
Damien George committed
687
688
STATIC mp_obj_t pyb_uart_deinit(mp_obj_t self_in) {
    pyb_uart_obj_t *self = self_in;
689
690
691
692
693
694
695
696
697
698
699
700
701
    self->is_enabled = false;
    UART_HandleTypeDef *uart = &self->uart;
    HAL_UART_DeInit(uart);
    if (uart->Instance == USART1) {
        HAL_NVIC_DisableIRQ(USART1_IRQn);
        __USART1_FORCE_RESET();
        __USART1_RELEASE_RESET();
        __USART1_CLK_DISABLE();
    } else if (uart->Instance == USART2) {
        HAL_NVIC_DisableIRQ(USART2_IRQn);
        __USART2_FORCE_RESET();
        __USART2_RELEASE_RESET();
        __USART2_CLK_DISABLE();
702
    #if defined(USART3)
703
704
705
706
707
    } else if (uart->Instance == USART3) {
        HAL_NVIC_DisableIRQ(USART3_IRQn);
        __USART3_FORCE_RESET();
        __USART3_RELEASE_RESET();
        __USART3_CLK_DISABLE();
708
709
    #endif
    #if defined(UART4)
710
711
712
713
714
    } else if (uart->Instance == UART4) {
        HAL_NVIC_DisableIRQ(UART4_IRQn);
        __UART4_FORCE_RESET();
        __UART4_RELEASE_RESET();
        __UART4_CLK_DISABLE();
715
    #endif
Dave Hylands's avatar
Dave Hylands committed
716
717
718
719
720
721
722
    #if defined(UART5)
    } else if (uart->Instance == UART5) {
        HAL_NVIC_DisableIRQ(UART5_IRQn);
        __UART5_FORCE_RESET();
        __UART5_RELEASE_RESET();
        __UART5_CLK_DISABLE();
    #endif
723
    #if defined(UART6)
724
725
726
727
728
    } else if (uart->Instance == USART6) {
        HAL_NVIC_DisableIRQ(USART6_IRQn);
        __USART6_FORCE_RESET();
        __USART6_RELEASE_RESET();
        __USART6_CLK_DISABLE();
729
    #endif
730
731
732
733
734
735
736
737
738
739
740
741
742
743
    #if defined(UART7)
    } else if (uart->Instance == UART7) {
        HAL_NVIC_DisableIRQ(UART7_IRQn);
        __UART7_FORCE_RESET();
        __UART7_RELEASE_RESET();
        __UART7_CLK_DISABLE();
    #endif
    #if defined(UART8)
    } else if (uart->Instance == UART8) {
        HAL_NVIC_DisableIRQ(UART8_IRQn);
        __UART8_FORCE_RESET();
        __UART8_RELEASE_RESET();
        __UART8_CLK_DISABLE();
    #endif
744
    }
745
746
    return mp_const_none;
}
Damien George's avatar
Damien George committed
747
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_deinit_obj, pyb_uart_deinit);
748

749
750
/// \method any()
/// Return `True` if any characters waiting, else `False`.
Damien George's avatar
Damien George committed
751
752
STATIC mp_obj_t pyb_uart_any(mp_obj_t self_in) {
    pyb_uart_obj_t *self = self_in;
753
    return MP_OBJ_NEW_SMALL_INT(uart_rx_any(self));
754
}
Damien George's avatar
Damien George committed
755
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_any_obj, pyb_uart_any);
756

757
758
/// \method writechar(char)
/// Write a single character on the bus.  `char` is an integer to write.
759
/// Return value: `None`.
760
761
STATIC mp_obj_t pyb_uart_writechar(mp_obj_t self_in, mp_obj_t char_in) {
    pyb_uart_obj_t *self = self_in;
762

763
764
    // get the character to write (might be 9 bits)
    uint16_t data = mp_obj_get_int(char_in);
765

766
767
768
769
770
771
772
    // write the character
    HAL_StatusTypeDef status;
    if (uart_tx_wait(self, self->timeout)) {
        status = uart_tx_data(self, (uint8_t*)&data, 1);
    } else {
        status = HAL_TIMEOUT;
    }
773
774

    if (status != HAL_OK) {
775
        mp_hal_raise(status);
776
    }
777

778
779
    return mp_const_none;
}
780
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_uart_writechar_obj, pyb_uart_writechar);
781

782
783
784
785
786
787
788
789
790
791
792
793
794
795
/// \method readchar()
/// Receive a single character on the bus.
/// Return value: The character read, as an integer.  Returns -1 on timeout.
STATIC mp_obj_t pyb_uart_readchar(mp_obj_t self_in) {
    pyb_uart_obj_t *self = self_in;
    if (uart_rx_wait(self, self->timeout)) {
        return MP_OBJ_NEW_SMALL_INT(uart_rx_char(self));
    } else {
        // return -1 on timeout
        return MP_OBJ_NEW_SMALL_INT(-1);
    }
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_readchar_obj, pyb_uart_readchar);

796
797
798
// uart.sendbreak()
STATIC mp_obj_t pyb_uart_sendbreak(mp_obj_t self_in) {
    pyb_uart_obj_t *self = self_in;
799
    #if defined(MCU_SERIES_F7) || defined(MCU_SERIES_L4)
800
801
    self->uart.Instance->RQR = USART_RQR_SBKRQ; // write-only register
    #else
802
    self->uart.Instance->CR1 |= USART_CR1_SBK;
803
    #endif
804
805
806
807
    return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_sendbreak_obj, pyb_uart_sendbreak);

Damien George's avatar
Damien George committed
808
STATIC const mp_map_elem_t pyb_uart_locals_dict_table[] = {
809
    // instance methods
810

Damien George's avatar
Damien George committed
811
812
813
    { MP_OBJ_NEW_QSTR(MP_QSTR_init), (mp_obj_t)&pyb_uart_init_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_deinit), (mp_obj_t)&pyb_uart_deinit_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_any), (mp_obj_t)&pyb_uart_any_obj },
814
815
816
817
818

    /// \method read([nbytes])
    { MP_OBJ_NEW_QSTR(MP_QSTR_read), (mp_obj_t)&mp_stream_read_obj },
    /// \method readline()
    { MP_OBJ_NEW_QSTR(MP_QSTR_readline), (mp_obj_t)&mp_stream_unbuffered_readline_obj},
Damien George's avatar
Damien George committed
819
820
    /// \method readinto(buf[, nbytes])
    { MP_OBJ_NEW_QSTR(MP_QSTR_readinto), (mp_obj_t)&mp_stream_readinto_obj },
821
822
823
824
825
    /// \method write(buf)
    { MP_OBJ_NEW_QSTR(MP_QSTR_write), (mp_obj_t)&mp_stream_write_obj },

    { MP_OBJ_NEW_QSTR(MP_QSTR_writechar), (mp_obj_t)&pyb_uart_writechar_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_readchar), (mp_obj_t)&pyb_uart_readchar_obj },
826
    { MP_OBJ_NEW_QSTR(MP_QSTR_sendbreak), (mp_obj_t)&pyb_uart_sendbreak_obj },
827
828
829
830

    // class constants
    { MP_OBJ_NEW_QSTR(MP_QSTR_RTS), MP_OBJ_NEW_SMALL_INT(UART_HWCONTROL_RTS) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_CTS), MP_OBJ_NEW_SMALL_INT(UART_HWCONTROL_CTS) },
831
832
};

Damien George's avatar
Damien George committed
833
STATIC MP_DEFINE_CONST_DICT(pyb_uart_locals_dict, pyb_uart_locals_dict_table);
834

835
836
837
838
839
840
STATIC mp_uint_t pyb_uart_read(mp_obj_t self_in, void *buf_in, mp_uint_t size, int *errcode) {
    pyb_uart_obj_t *self = self_in;
    byte *buf = buf_in;

    // check that size is a multiple of character width
    if (size & self->char_width) {
841
        *errcode = MP_EIO;
842
843
844
845
846
847
848
849
850
851
852
853
854
        return MP_STREAM_ERROR;
    }

    // convert byte size to char size
    size >>= self->char_width;

    // make sure we want at least 1 char
    if (size == 0) {
        return 0;
    }

    // wait for first char to become available
    if (!uart_rx_wait(self, self->timeout)) {
855
        // return EAGAIN error to indicate non-blocking (then read() method returns None)
856
        *errcode = MP_EAGAIN;
857
        return MP_STREAM_ERROR;
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
    }

    // read the data
    byte *orig_buf = buf;
    for (;;) {
        int data = uart_rx_char(self);
        if (self->char_width == CHAR_WIDTH_9BIT) {
            *(uint16_t*)buf = data;
            buf += 2;
        } else {
            *buf++ = data;
        }
        if (--size == 0 || !uart_rx_wait(self, self->timeout_char)) {
            // return number of bytes read
            return buf - orig_buf;
        }
    }
}

STATIC mp_uint_t pyb_uart_write(mp_obj_t self_in, const void *buf_in, mp_uint_t size, int *errcode) {
    pyb_uart_obj_t *self = self_in;
    const byte *buf = buf_in;

    // check that size is a multiple of character width
    if (size & self->char_width) {
883
        *errcode = MP_EIO;
884
885
886
        return MP_STREAM_ERROR;
    }

887
    // wait to be able to write the first character. EAGAIN causes write to return None
888
    if (!uart_tx_wait(self, self->timeout)) {
889
        *errcode = MP_EAGAIN;
890
891
892
        return MP_STREAM_ERROR;
    }

893
    // write the data
894
    HAL_StatusTypeDef status = uart_tx_data(self, (uint8_t*)buf, size >> self->char_width);
895
896
897
898

    if (status == HAL_OK) {
        // return number of bytes written
        return size;
899
900
901
902
903
904
905
906
907
908
909
    } else if (status == HAL_TIMEOUT) { // UART_WaitOnFlagUntilTimeout() disables RXNE interrupt on timeout
        if (self->read_buf_len > 0) {
            __HAL_UART_ENABLE_IT(&self->uart, UART_IT_RXNE); // re-enable RXNE
        }
        // return number of bytes written
        if (self->char_width == CHAR_WIDTH_8BIT) {
            return size - self->uart.TxXferCount - 1;
        } else {
            int written = self->uart.TxXferCount * 2;
            return size - written - 2;
        }
910
    } else {
911
        *errcode = mp_hal_status_to_errno_table[status];
912
913
914
915
        return MP_STREAM_ERROR;
    }
}

916
STATIC mp_uint_t pyb_uart_ioctl(mp_obj_t self_in, mp_uint_t request, mp_uint_t arg, int *errcode) {
917
918
    pyb_uart_obj_t *self = self_in;
    mp_uint_t ret;
919
    if (request == MP_STREAM_POLL) {
920
        mp_uint_t flags = arg;
921
        ret = 0;
922
923
        if ((flags & MP_STREAM_POLL_RD) && uart_rx_any(self)) {
            ret |= MP_STREAM_POLL_RD;
924
        }
925
926
        if ((flags & MP_STREAM_POLL_WR) && __HAL_UART_GET_FLAG(&self->uart, UART_FLAG_TXE)) {
            ret |= MP_STREAM_POLL_WR;
927
928
        }
    } else {
929
        *errcode = MP_EINVAL;
930
        ret = MP_STREAM_ERROR;
931
932
933
934
935
    }
    return ret;
}

STATIC const mp_stream_p_t uart_stream_p = {
936
937
938
    .read = pyb_uart_read,
    .write = pyb_uart_write,
    .ioctl = pyb_uart_ioctl,
939
940
941
    .is_text = false,
};

Damien George's avatar
Damien George committed
942
const mp_obj_type_t pyb_uart_type = {
943
    { &mp_type_type },
Damien George's avatar
Damien George committed
944
945
946
    .name = MP_QSTR_UART,
    .print = pyb_uart_print,
    .make_new = pyb_uart_make_new,
947
948
    .getiter = mp_identity,
    .iternext = mp_stream_unbuffered_iter,
949
    .protocol = &uart_stream_p,
Damien George's avatar
Damien George committed
950
    .locals_dict = (mp_obj_t)&pyb_uart_locals_dict,
951
};