aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/chibios/serial_usart.c
blob: 62b4913cbfbb0781b1f92d2d3c928af26dc00800 (plain)
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
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
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
195
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
226
227
228
229
230
231
232
233
234
#include "quantum.h"
#include "serial.h"
#include "printf.h"

#include "ch.h"
#include "hal.h"

#ifndef USART_CR1_M0
#    define USART_CR1_M0 USART_CR1_M  // some platforms (f1xx) dont have this so
#endif

#ifndef USE_GPIOV1
// The default PAL alternate modes are used to signal that the pins are used for USART
#    ifndef SERIAL_USART_TX_PAL_MODE
#        define SERIAL_USART_TX_PAL_MODE 7
#    endif
#endif

#ifndef SERIAL_USART_DRIVER
#    define SERIAL_USART_DRIVER SD1
#endif

#ifndef SERIAL_USART_CR1
#    define SERIAL_USART_CR1 (USART_CR1_PCE | USART_CR1_PS | USART_CR1_M0)  // parity enable, odd parity, 9 bit length
#endif

#ifndef SERIAL_USART_CR2
#    define SERIAL_USART_CR2 (USART_CR2_STOP_1)  // 2 stop bits
#endif

#ifndef SERIAL_USART_CR3
#    define SERIAL_USART_CR3 0
#endif

#ifdef SOFT_SERIAL_PIN
#    define SERIAL_USART_TX_PIN SOFT_SERIAL_PIN
#endif

#ifndef SELECT_SOFT_SERIAL_SPEED
#    define SELECT_SOFT_SERIAL_SPEED 1
#endif

#ifdef SERIAL_USART_SPEED
// Allow advanced users to directly set SERIAL_USART_SPEED
#elif SELECT_SOFT_SERIAL_SPEED == 0
#    define SERIAL_USART_SPEED 460800
#elif SELECT_SOFT_SERIAL_SPEED == 1
#    define SERIAL_USART_SPEED 230400
#elif SELECT_SOFT_SERIAL_SPEED == 2
#    define SERIAL_USART_SPEED 115200
#elif SELECT_SOFT_SERIAL_SPEED == 3
#    define SERIAL_USART_SPEED 57600
#elif SELECT_SOFT_SERIAL_SPEED == 4
#    define SERIAL_USART_SPEED 38400
#elif SELECT_SOFT_SERIAL_SPEED == 5
#    define SERIAL_USART_SPEED 19200
#else
#    error invalid SELECT_SOFT_SERIAL_SPEED value
#endif

#define TIMEOUT 100
#define HANDSHAKE_MAGIC 7

static inline msg_t sdWriteHalfDuplex(SerialDriver* driver, uint8_t* data, uint8_t size) {
    msg_t ret = sdWrite(driver, data, size);

    // Half duplex requires us to read back the data we just wrote - just throw it away
    uint8_t dump[size];
    sdRead(driver, dump, size);

    return ret;
}
#undef sdWrite
#define sdWrite sdWriteHalfDuplex

static inline msg_t sdWriteTimeoutHalfDuplex(SerialDriver* driver, uint8_t* data, uint8_t size, uint32_t timeout) {
    msg_t ret = sdWriteTimeout(driver, data, size, timeout);

    // Half duplex requires us to read back the data we just wrote - just throw it away
    uint8_t dump[size];
    sdReadTimeout(driver, dump, size, timeout);

    return ret;
}
#undef sdWriteTimeout
#define sdWriteTimeout sdWriteTimeoutHalfDuplex

static inline void sdClear(SerialDriver* driver) {
    while (sdGetTimeout(driver, TIME_IMMEDIATE) != MSG_TIMEOUT) {
        // Do nothing with the data
    }
}

static SerialConfig sdcfg = {
    (SERIAL_USART_SPEED),  // speed - mandatory
    (SERIAL_USART_CR1),    // CR1
    (SERIAL_USART_CR2),    // CR2
    (SERIAL_USART_CR3)     // CR3
};

void handle_soft_serial_slave(void);

/*
 * This thread runs on the slave and responds to transactions initiated
 * by the master
 */
static THD_WORKING_AREA(waSlaveThread, 2048);
static THD_FUNCTION(SlaveThread, arg) {
    (void)arg;
    chRegSetThreadName("slave_transport");

    while (true) {
        handle_soft_serial_slave();
    }
}

__attribute__((weak)) void usart_init(void) {
#if defined(USE_GPIOV1)
    palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_STM32_ALTERNATE_OPENDRAIN);
#else
    palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_TX_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN);
#endif
}

void usart_master_init(void) {
    usart_init();

    sdcfg.cr3 |= USART_CR3_HDSEL;
    sdStart(&SERIAL_USART_DRIVER, &sdcfg);
}

void usart_slave_init(void) {
    usart_init();

    sdcfg.cr3 |= USART_CR3_HDSEL;
    sdStart(&SERIAL_USART_DRIVER, &sdcfg);

    // Start transport thread
    chThdCreateStatic(waSlaveThread, sizeof(waSlaveThread), HIGHPRIO, SlaveThread, NULL);
}

static SSTD_t* Transaction_table      = NULL;
static uint8_t Transaction_table_size = 0;

void soft_serial_initiator_init(SSTD_t* sstd_table, int sstd_table_size) {
    Transaction_table      = sstd_table;
    Transaction_table_size = (uint8_t)sstd_table_size;

    usart_master_init();
}

void soft_serial_target_init(SSTD_t* sstd_table, int sstd_table_size) {
    Transaction_table      = sstd_table;
    Transaction_table_size = (uint8_t)sstd_table_size;

    usart_slave_init();
}

void handle_soft_serial_slave(void) {
    uint8_t sstd_index = sdGet(&SERIAL_USART_DRIVER);  // first chunk is always transaction id
    SSTD_t* trans      = &Transaction_table[sstd_index];

    // Always write back the sstd_index as part of a basic handshake
    sstd_index ^= HANDSHAKE_MAGIC;
    sdWrite(&SERIAL_USART_DRIVER, &sstd_index, sizeof(sstd_index));

    if (trans->initiator2target_buffer_size) {
        sdRead(&SERIAL_USART_DRIVER, trans->initiator2target_buffer, trans->initiator2target_buffer_size);
    }

    if (trans->target2initiator_buffer_size) {
        sdWrite(&SERIAL_USART_DRIVER, trans->target2initiator_buffer, trans->target2initiator_buffer_size);
    }

    if (trans->status) {
        *trans->status = TRANSACTION_ACCEPTED;
    }
}

/////////
//  start transaction by initiator
//
// int  soft_serial_transaction(int sstd_index)
//
// Returns:
//    TRANSACTION_END
//    TRANSACTION_NO_RESPONSE
//    TRANSACTION_DATA_ERROR
#ifndef SERIAL_USE_MULTI_TRANSACTION
int soft_serial_transaction(void) {
    uint8_t sstd_index = 0;
#else
int soft_serial_transaction(int index) {
    uint8_t sstd_index = index;
#endif

    if (sstd_index > Transaction_table_size) return TRANSACTION_TYPE_ERROR;
    SSTD_t* trans = &Transaction_table[sstd_index];
    msg_t   res   = 0;

    sdClear(&SERIAL_USART_DRIVER);

    // First chunk is always transaction id
    sdWriteTimeout(&SERIAL_USART_DRIVER, &sstd_index, sizeof(sstd_index), TIME_MS2I(TIMEOUT));

    uint8_t sstd_index_shake = 0xFF;

    // Which we always read back first so that we can error out correctly
    //   - due to the half duplex limitations on return codes, we always have to read *something*
    //   - without the read, write only transactions *always* succeed, even during the boot process where the slave is not ready
    res = sdReadTimeout(&SERIAL_USART_DRIVER, &sstd_index_shake, sizeof(sstd_index_shake), TIME_MS2I(TIMEOUT));
    if (res < 0 || (sstd_index_shake != (sstd_index ^ HANDSHAKE_MAGIC))) {
        dprintf("serial::usart_shake NO_RESPONSE\n");
        return TRANSACTION_NO_RESPONSE;
    }

    if (trans->initiator2target_buffer_size) {
        res = sdWriteTimeout(&SERIAL_USART_DRIVER, trans->initiator2target_buffer, trans->initiator2target_buffer_size, TIME_MS2I(TIMEOUT));
        if (res < 0) {
            dprintf("serial::usart_transmit NO_RESPONSE\n");
            return TRANSACTION_NO_RESPONSE;
        }
    }

    if (trans->target2initiator_buffer_size) {
        res = sdReadTimeout(&SERIAL_USART_DRIVER, trans->target2initiator_buffer, trans->target2initiator_buffer_size, TIME_MS2I(TIMEOUT));
        if (res < 0) {
            dprintf("serial::usart_receive NO_RESPONSE\n");
            return TRANSACTION_NO_RESPONSE;
        }
    }

    return TRANSACTION_END;
}