spi.c 13.4 KB
Newer Older
Damien George's avatar
Damien George committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
#include <stdio.h>
#include <string.h>

#include "stm32f4xx_hal.h"

#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
#include "pin.h"
#include "genhdr/pins.h"
#include "spi.h"

16
17
18
19
#if !defined(MICROPU_HW_ENABLE_SPI1)
#define MICROPY_HW_ENABLE_SPI1  (1)
#endif

Damien George's avatar
Damien George committed
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
SPI_HandleTypeDef SPIHandle1 = {.Instance = NULL};
SPI_HandleTypeDef SPIHandle2 = {.Instance = NULL};
SPI_HandleTypeDef SPIHandle3 = {.Instance = NULL};

void spi_init0(void) {
    // reset the SPI handles
    memset(&SPIHandle1, 0, sizeof(SPI_HandleTypeDef));
    SPIHandle1.Instance = SPI1;
    memset(&SPIHandle2, 0, sizeof(SPI_HandleTypeDef));
    SPIHandle2.Instance = SPI2;
    memset(&SPIHandle3, 0, sizeof(SPI_HandleTypeDef));
    SPIHandle3.Instance = SPI3;
}

// TODO allow to take a list of pins to use
void spi_init(SPI_HandleTypeDef *spi) {
36
37
38
39
40
41
    // init the GPIO lines
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStructure.Speed = GPIO_SPEED_FAST;
    GPIO_InitStructure.Pull = GPIO_PULLUP; // ST examples use PULLUP

Damien George's avatar
Damien George committed
42
    const pin_obj_t *pins[4];
43
#if MICROPY_HW_ENABLE_SPI1
Damien George's avatar
Damien George committed
44
45
46
47
48
49
    if (spi->Instance == SPI1) {
        // X-skin: X5=PA4=SPI1_NSS, X6=PA5=SPI1_SCK, X7=PA6=SPI1_MISO, X8=PA7=SPI1_MOSI
        pins[0] = &pin_A4;
        pins[1] = &pin_A5;
        pins[2] = &pin_A6;
        pins[3] = &pin_A7;
50
        GPIO_InitStructure.Alternate = GPIO_AF5_SPI1;
51
52
53
    } else
#endif
    if (spi->Instance == SPI2) {
Damien George's avatar
Damien George committed
54
55
56
57
58
        // Y-skin: Y5=PB12=SPI2_NSS, Y6=PB13=SPI2_SCK, Y7=PB14=SPI2_MISO, Y8=PB15=SPI2_MOSI
        pins[0] = &pin_B12;
        pins[1] = &pin_B13;
        pins[2] = &pin_B14;
        pins[3] = &pin_B15;
59
        GPIO_InitStructure.Alternate = GPIO_AF5_SPI2;
60
    } else
Damien George's avatar
Damien George committed
61
#if MICROPY_HW_ENABLE_SPI3
62
    if (spi->Instance == SPI3) {
Damien George's avatar
Damien George committed
63
64
65
66
        pins[0] = &pin_A4;
        pins[1] = &pin_B3;
        pins[2] = &pin_B4;
        pins[3] = &pin_B5;
67
        GPIO_InitStructure.Alternate = GPIO_AF6_SPI3;
68
    } else
Damien George's avatar
Damien George committed
69
#endif
70
    {
Damien George's avatar
Damien George committed
71
        // SPI does not exist for this board
72
        nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "SPI bus does not exist"));
Damien George's avatar
Damien George committed
73
74
75
76
77
78
79
80
81
82
83
84
    }

    for (uint i = 0; i < 4; i++) {
        GPIO_InitStructure.Pin = pins[i]->pin_mask;
        HAL_GPIO_Init(pins[i]->gpio, &GPIO_InitStructure);
    }

    // enable the SPI clock
    if (spi->Instance == SPI1) {
        __SPI1_CLK_ENABLE();
    } else if (spi->Instance == SPI2) {
        __SPI2_CLK_ENABLE();
85
    } else if (spi->Instance == SPI3) {
Damien George's avatar
Damien George committed
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
        __SPI3_CLK_ENABLE();
    }

    // init the I2C device
    if (HAL_SPI_Init(spi) != HAL_OK) {
        // init error
        // TODO should raise an exception, but this function is not necessarily going to be
        // called via Python, so may not be properly wrapped in an NLR handler
        printf("HardwareError: HAL_SPI_Init failed\n");
        return;
    }
}

void spi_deinit(SPI_HandleTypeDef *spi) {
    HAL_SPI_DeInit(spi);
    if (spi->Instance == SPI1) {
        __SPI1_CLK_DISABLE();
    } else if (spi->Instance == SPI2) {
        __SPI2_CLK_DISABLE();
105
    } else if (spi->Instance == SPI3) {
Damien George's avatar
Damien George committed
106
107
108
109
110
111
112
        __SPI3_CLK_DISABLE();
    }
}

/******************************************************************************/
/* Micro Python bindings                                                      */

113
#define PYB_NUM_SPI (2)
Damien George's avatar
Damien George committed
114
115
116
117
118
119

typedef struct _pyb_spi_obj_t {
    mp_obj_base_t base;
    SPI_HandleTypeDef *spi;
} pyb_spi_obj_t;

120
121
122
123
STATIC const pyb_spi_obj_t pyb_spi_obj[PYB_NUM_SPI] = {
    {{&pyb_spi_type}, &SPIHandle1},
    {{&pyb_spi_type}, &SPIHandle2}
};
Damien George's avatar
Damien George committed
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194

STATIC void pyb_spi_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
    pyb_spi_obj_t *self = self_in;

    uint spi_num;
    if (self->spi->Instance == SPI1) { spi_num = 1; }
    else if (self->spi->Instance == SPI2) { spi_num = 2; }
    else { spi_num = 3; }

    if (self->spi->State == HAL_SPI_STATE_RESET) {
        print(env, "SPI(%u)", spi_num);
    } else {
        if (self->spi->Init.Mode == SPI_MODE_MASTER) {
            // compute baudrate
            uint spi_clock;
            if (self->spi->Instance == SPI1) {
                // SPI1 is on APB2
                spi_clock = HAL_RCC_GetPCLK2Freq();
            } else {
                // SPI2 and SPI3 are on APB1
                spi_clock = HAL_RCC_GetPCLK1Freq();
            }
            uint baudrate = spi_clock >> ((self->spi->Init.BaudRatePrescaler >> 3) + 1);
            print(env, "SPI(%u, SPI.MASTER, clock=%u, baudrate=%u)", spi_num, spi_clock, baudrate);
        } else {
            print(env, "SPI(%u, SPI.SLAVE)", spi_num);
        }
    }
}

STATIC const mp_arg_parse_t pyb_spi_init_accepted_args[] = {
    { MP_QSTR_mode,     MP_ARG_PARSE_REQUIRED | MP_ARG_PARSE_INT, {.u_int = 0} },
    { MP_QSTR_baudrate, MP_ARG_PARSE_INT,  {.u_int = 328125} },
    { MP_QSTR_clkpol,   MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT,  {.u_int = SPI_POLARITY_LOW} },
    { MP_QSTR_clkphase, MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT,  {.u_int = SPI_PHASE_1EDGE} },
    { MP_QSTR_dir,      MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT,  {.u_int = SPI_DIRECTION_2LINES} },
    { MP_QSTR_size,     MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT,  {.u_int = 8} },
    { MP_QSTR_nss,      MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT,  {.u_int = SPI_NSS_SOFT} },
    { MP_QSTR_firstbit, MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_INT,  {.u_int = SPI_FIRSTBIT_MSB} },
    { MP_QSTR_ti,       MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_BOOL, {.u_bool = false} },
    { MP_QSTR_crcpoly,  MP_ARG_PARSE_KW_ONLY | MP_ARG_PARSE_OBJ,  {.u_obj = mp_const_none} },
};
#define PYB_SPI_INIT_NUM_ARGS (sizeof(pyb_spi_init_accepted_args) / sizeof(pyb_spi_init_accepted_args[0]))

STATIC mp_obj_t pyb_spi_init_helper(const pyb_spi_obj_t *self, uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
    // parse keyword args
    mp_arg_parse_val_t vals[PYB_SPI_INIT_NUM_ARGS];
    mp_arg_parse_all(n_args, args, kw_args, PYB_SPI_INIT_NUM_ARGS, pyb_spi_init_accepted_args, vals);

    // set the SPI configuration values
    SPI_InitTypeDef *init = &self->spi->Init;
    init->Mode = vals[0].u_int;

    // compute the baudrate prescaler from the requested baudrate
    // select a prescaler that yields at most the requested baudrate
    uint spi_clock;
    if (self->spi->Instance == SPI1) {
        // SPI1 is on APB2
        spi_clock = HAL_RCC_GetPCLK2Freq();
    } else {
        // SPI2 and SPI3 are on APB1
        spi_clock = HAL_RCC_GetPCLK1Freq();
    }
    uint br_prescale = spi_clock / vals[1].u_int;
    if (br_prescale <= 2) { init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2; }
    else if (br_prescale <= 4) { init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_4; }
    else if (br_prescale <= 8) { init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_8; }
    else if (br_prescale <= 16) { init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_16; }
    else if (br_prescale <= 32) { init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_32; }
    else if (br_prescale <= 64) { init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_64; }
    else if (br_prescale <= 128) { init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_128; }
195
    else { init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_256; }
Damien George's avatar
Damien George committed
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225

    init->CLKPolarity = vals[2].u_int;
    init->CLKPhase = vals[3].u_int;
    init->Direction = vals[4].u_int;
    init->DataSize = (vals[5].u_int == 16) ? SPI_DATASIZE_16BIT : SPI_DATASIZE_8BIT;
    init->NSS = vals[6].u_int;
    init->FirstBit = vals[7].u_int;
    init->TIMode = vals[8].u_bool ? SPI_TIMODE_ENABLED : SPI_TIMODE_DISABLED;
    if (vals[9].u_obj == mp_const_none) {
        init->CRCCalculation = SPI_CRCCALCULATION_DISABLED;
        init->CRCPolynomial = 0;
    } else {
        init->CRCCalculation = SPI_CRCCALCULATION_ENABLED;
        init->CRCPolynomial = mp_obj_get_int(vals[9].u_obj);
    }

    // init the SPI bus
    spi_init(self->spi);

    return mp_const_none;
}

STATIC mp_obj_t pyb_spi_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
    // check arguments
    mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);

    // get SPI number
    machine_int_t spi_id = mp_obj_get_int(args[0]) - 1;

    // check SPI number
226
    if (!(0 <= spi_id && spi_id < PYB_NUM_SPI)) {
Damien George's avatar
Damien George committed
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "SPI bus %d does not exist", spi_id + 1));
    }

    // get SPI object
    const pyb_spi_obj_t *spi_obj = &pyb_spi_obj[spi_id];

    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);
        pyb_spi_init_helper(spi_obj, n_args - 1, args + 1, &kw_args);
    }

    return (mp_obj_t)spi_obj;
}

STATIC mp_obj_t pyb_spi_init(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
    return pyb_spi_init_helper(args[0], n_args - 1, args + 1, kw_args);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_spi_init_obj, 1, pyb_spi_init);

STATIC mp_obj_t pyb_spi_deinit(mp_obj_t self_in) {
    pyb_spi_obj_t *self = self_in;
    spi_deinit(self->spi);
    return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_spi_deinit_obj, pyb_spi_deinit);

STATIC mp_obj_t pyb_spi_send(mp_obj_t self_in, mp_obj_t data_in) {
    // TODO assumes transmission size is 8-bits wide
    // TODO accept timeout as keyword argument

    pyb_spi_obj_t *self = self_in;

    uint8_t data[1];
    mp_buffer_info_t bufinfo;
    if (MP_OBJ_IS_INT(data_in)) {
        data[0] = mp_obj_get_int(data_in);
        bufinfo.buf = data;
        bufinfo.len = 1;
        bufinfo.typecode = 'B';
    } else {
        mp_get_buffer_raise(data_in, &bufinfo, MP_BUFFER_READ);
    }

    HAL_StatusTypeDef status = HAL_SPI_Transmit(self->spi, bufinfo.buf, bufinfo.len, 1000);

    if (status != HAL_OK) {
        // TODO really need a HardwareError object, or something
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_SPI_Transmit failed with code %d", status));
    }

    return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_spi_send_obj, pyb_spi_send);

STATIC mp_obj_t pyb_spi_recv(mp_obj_t self_in, mp_obj_t n_in) {
    // TODO assumes transmission size is 8-bits wide
    // TODO accept timeout as keyword argument

    pyb_spi_obj_t *self = self_in;
    machine_uint_t n = mp_obj_get_int(n_in);

    byte *data;
    mp_obj_t o = mp_obj_str_builder_start(&mp_type_bytes, n, &data);
    HAL_StatusTypeDef status = HAL_SPI_Receive(self->spi, data, n, 1000);

    if (status != HAL_OK) {
        // TODO really need a HardwareError object, or something
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_SPI_Receive failed with code %d", status));
    }

    return mp_obj_str_builder_end(o);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_spi_recv_obj, pyb_spi_recv);

STATIC mp_obj_t pyb_spi_send_recv(mp_obj_t self_in, mp_obj_t data_in) {
    // TODO assumes transmission size is 8-bits wide
    // TODO accept timeout as keyword argument

    pyb_spi_obj_t *self = self_in;

    uint8_t data_send[1];
    mp_buffer_info_t bufinfo;
    if (MP_OBJ_IS_INT(data_in)) {
        data_send[0] = mp_obj_get_int(data_in);
        bufinfo.buf = data_send;
        bufinfo.len = 1;
        bufinfo.typecode = 'B';
    } else {
        mp_get_buffer_raise(data_in, &bufinfo, MP_BUFFER_READ);
    }

    byte *data_recv;
    mp_obj_t o = mp_obj_str_builder_start(&mp_type_bytes, bufinfo.len, &data_recv);
    HAL_StatusTypeDef status = HAL_SPI_TransmitReceive(self->spi, bufinfo.buf, data_recv, bufinfo.len, 1000);

    if (status != HAL_OK) {
        // TODO really need a HardwareError object, or something
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_SPI_TransmitReceive failed with code %d", status));
    }

    return mp_obj_str_builder_end(o);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_spi_send_recv_obj, pyb_spi_send_recv);

STATIC const mp_map_elem_t pyb_spi_locals_dict_table[] = {
    // instance methods
    { MP_OBJ_NEW_QSTR(MP_QSTR_init), (mp_obj_t)&pyb_spi_init_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_deinit), (mp_obj_t)&pyb_spi_deinit_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_send), (mp_obj_t)&pyb_spi_send_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_recv), (mp_obj_t)&pyb_spi_recv_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_send_recv), (mp_obj_t)&pyb_spi_send_recv_obj },

    // class constants
    { MP_OBJ_NEW_QSTR(MP_QSTR_MASTER),        MP_OBJ_NEW_SMALL_INT(SPI_MODE_MASTER) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_SLAVE),        MP_OBJ_NEW_SMALL_INT(SPI_MODE_SLAVE) },
    /* TODO
    { MP_OBJ_NEW_QSTR(MP_QSTR_DIRECTION_2LINES             ((uint32_t)0x00000000)
    { MP_OBJ_NEW_QSTR(MP_QSTR_DIRECTION_2LINES_RXONLY      SPI_CR1_RXONLY
    { MP_OBJ_NEW_QSTR(MP_QSTR_DIRECTION_1LINE              SPI_CR1_BIDIMODE
    { MP_OBJ_NEW_QSTR(MP_QSTR_POLARITY_LOW                ((uint32_t)0x00000000)
    { MP_OBJ_NEW_QSTR(MP_QSTR_POLARITY_HIGH               SPI_CR1_CPOL
    { MP_OBJ_NEW_QSTR(MP_QSTR_PHASE_1EDGE                 ((uint32_t)0x00000000)
    { MP_OBJ_NEW_QSTR(MP_QSTR_PHASE_2EDGE                 SPI_CR1_CPHA
    { MP_OBJ_NEW_QSTR(MP_QSTR_NSS_SOFT                    SPI_CR1_SSM
    { MP_OBJ_NEW_QSTR(MP_QSTR_NSS_HARD_INPUT              ((uint32_t)0x00000000)
    { MP_OBJ_NEW_QSTR(MP_QSTR_NSS_HARD_OUTPUT             ((uint32_t)0x00040000)
    { MP_OBJ_NEW_QSTR(MP_QSTR_FIRSTBIT_MSB                ((uint32_t)0x00000000)
    { MP_OBJ_NEW_QSTR(MP_QSTR_FIRSTBIT_LSB                SPI_CR1_LSBFIRST
    */
};

STATIC MP_DEFINE_CONST_DICT(pyb_spi_locals_dict, pyb_spi_locals_dict_table);

const mp_obj_type_t pyb_spi_type = {
    { &mp_type_type },
    .name = MP_QSTR_SPI,
    .print = pyb_spi_print,
    .make_new = pyb_spi_make_new,
    .locals_dict = (mp_obj_t)&pyb_spi_locals_dict,
};