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Diffstat (limited to 'platforms/chibios/drivers/serial_usart.c')
-rw-r--r--platforms/chibios/drivers/serial_usart.c318
1 files changed, 318 insertions, 0 deletions
diff --git a/platforms/chibios/drivers/serial_usart.c b/platforms/chibios/drivers/serial_usart.c
new file mode 100644
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+++ b/platforms/chibios/drivers/serial_usart.c
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1/* Copyright 2021 QMK
2 *
3 * This program is free software: you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation, either version 3 of the License, or
6 * (at your option) any later version.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16
17#include "serial_usart.h"
18
19#if defined(SERIAL_USART_CONFIG)
20static SerialConfig serial_config = SERIAL_USART_CONFIG;
21#else
22static SerialConfig serial_config = {
23 .speed = (SERIAL_USART_SPEED), /* speed - mandatory */
24 .cr1 = (SERIAL_USART_CR1),
25 .cr2 = (SERIAL_USART_CR2),
26# if !defined(SERIAL_USART_FULL_DUPLEX)
27 .cr3 = ((SERIAL_USART_CR3) | USART_CR3_HDSEL) /* activate half-duplex mode */
28# else
29 .cr3 = (SERIAL_USART_CR3)
30# endif
31};
32#endif
33
34static SerialDriver* serial_driver = &SERIAL_USART_DRIVER;
35
36static inline bool react_to_transactions(void);
37static inline bool __attribute__((nonnull)) receive(uint8_t* destination, const size_t size);
38static inline bool __attribute__((nonnull)) send(const uint8_t* source, const size_t size);
39static inline int initiate_transaction(uint8_t sstd_index);
40static inline void usart_clear(void);
41
42/**
43 * @brief Clear the receive input queue.
44 */
45static inline void usart_clear(void) {
46 osalSysLock();
47 bool volatile queue_not_empty = !iqIsEmptyI(&serial_driver->iqueue);
48 osalSysUnlock();
49
50 while (queue_not_empty) {
51 osalSysLock();
52 /* Hard reset the input queue. */
53 iqResetI(&serial_driver->iqueue);
54 osalSysUnlock();
55 /* Allow pending interrupts to preempt.
56 * Do not merge the lock/unlock blocks into one
57 * or the code will not work properly.
58 * The empty read adds a tiny amount of delay. */
59 (void)queue_not_empty;
60 osalSysLock();
61 queue_not_empty = !iqIsEmptyI(&serial_driver->iqueue);
62 osalSysUnlock();
63 }
64}
65
66/**
67 * @brief Blocking send of buffer with timeout.
68 *
69 * @return true Send success.
70 * @return false Send failed.
71 */
72static inline bool send(const uint8_t* source, const size_t size) {
73 bool success = (size_t)sdWriteTimeout(serial_driver, source, size, TIME_MS2I(SERIAL_USART_TIMEOUT)) == size;
74
75#if !defined(SERIAL_USART_FULL_DUPLEX)
76 if (success) {
77 /* Half duplex fills the input queue with the data we wrote - just throw it away.
78 Under the right circumstances (e.g. bad cables paired with high baud rates)
79 less bytes can be present in the input queue, therefore a timeout is needed. */
80 uint8_t dump[size];
81 return receive(dump, size);
82 }
83#endif
84
85 return success;
86}
87
88/**
89 * @brief Blocking receive of size * bytes with timeout.
90 *
91 * @return true Receive success.
92 * @return false Receive failed.
93 */
94static inline bool receive(uint8_t* destination, const size_t size) {
95 bool success = (size_t)sdReadTimeout(serial_driver, destination, size, TIME_MS2I(SERIAL_USART_TIMEOUT)) == size;
96 return success;
97}
98
99#if !defined(SERIAL_USART_FULL_DUPLEX)
100
101/**
102 * @brief Initiate pins for USART peripheral. Half-duplex configuration.
103 */
104__attribute__((weak)) void usart_init(void) {
105# if defined(MCU_STM32)
106# if defined(USE_GPIOV1)
107 palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_STM32_ALTERNATE_OPENDRAIN);
108# else
109 palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_TX_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN);
110# endif
111
112# if defined(USART_REMAP)
113 USART_REMAP;
114# endif
115# else
116# pragma message "usart_init: MCU Familiy not supported by default, please supply your own init code by implementing usart_init() in your keyboard files."
117# endif
118}
119
120#else
121
122/**
123 * @brief Initiate pins for USART peripheral. Full-duplex configuration.
124 */
125__attribute__((weak)) void usart_init(void) {
126# if defined(MCU_STM32)
127# if defined(USE_GPIOV1)
128 palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_STM32_ALTERNATE_PUSHPULL);
129 palSetLineMode(SERIAL_USART_RX_PIN, PAL_MODE_INPUT);
130# else
131 palSetLineMode(SERIAL_USART_TX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_TX_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL | PAL_STM32_OSPEED_HIGHEST);
132 palSetLineMode(SERIAL_USART_RX_PIN, PAL_MODE_ALTERNATE(SERIAL_USART_RX_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL | PAL_STM32_OSPEED_HIGHEST);
133# endif
134
135# if defined(USART_REMAP)
136 USART_REMAP;
137# endif
138# else
139# pragma message "usart_init: MCU Familiy not supported by default, please supply your own init code by implementing usart_init() in your keyboard files."
140# endif
141}
142
143#endif
144
145/**
146 * @brief Overridable master specific initializations.
147 */
148__attribute__((weak, nonnull)) void usart_master_init(SerialDriver** driver) {
149 (void)driver;
150 usart_init();
151}
152
153/**
154 * @brief Overridable slave specific initializations.
155 */
156__attribute__((weak, nonnull)) void usart_slave_init(SerialDriver** driver) {
157 (void)driver;
158 usart_init();
159}
160
161/**
162 * @brief This thread runs on the slave and responds to transactions initiated
163 * by the master.
164 */
165static THD_WORKING_AREA(waSlaveThread, 1024);
166static THD_FUNCTION(SlaveThread, arg) {
167 (void)arg;
168 chRegSetThreadName("usart_tx_rx");
169
170 while (true) {
171 if (!react_to_transactions()) {
172 /* Clear the receive queue, to start with a clean slate.
173 * Parts of failed transactions or spurious bytes could still be in it. */
174 usart_clear();
175 }
176 }
177}
178
179/**
180 * @brief Slave specific initializations.
181 */
182void soft_serial_target_init(void) {
183 usart_slave_init(&serial_driver);
184
185 sdStart(serial_driver, &serial_config);
186
187 /* Start transport thread. */
188 chThdCreateStatic(waSlaveThread, sizeof(waSlaveThread), HIGHPRIO, SlaveThread, NULL);
189}
190
191/**
192 * @brief React to transactions started by the master.
193 */
194static inline bool react_to_transactions(void) {
195 /* Wait until there is a transaction for us. */
196 uint8_t sstd_index = (uint8_t)sdGet(serial_driver);
197
198 /* Sanity check that we are actually responding to a valid transaction. */
199 if (sstd_index >= NUM_TOTAL_TRANSACTIONS) {
200 return false;
201 }
202
203 split_transaction_desc_t* trans = &split_transaction_table[sstd_index];
204
205 /* Send back the handshake which is XORed as a simple checksum,
206 to signal that the slave is ready to receive possible transaction buffers */
207 sstd_index ^= HANDSHAKE_MAGIC;
208 if (!send(&sstd_index, sizeof(sstd_index))) {
209 *trans->status = TRANSACTION_DATA_ERROR;
210 return false;
211 }
212
213 /* Receive transaction buffer from the master. If this transaction requires it.*/
214 if (trans->initiator2target_buffer_size) {
215 if (!receive(split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size)) {
216 *trans->status = TRANSACTION_DATA_ERROR;
217 return false;
218 }
219 }
220
221 /* Allow any slave processing to occur. */
222 if (trans->slave_callback) {
223 trans->slave_callback(trans->initiator2target_buffer_size, split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size, split_trans_target2initiator_buffer(trans));
224 }
225
226 /* Send transaction buffer to the master. If this transaction requires it. */
227 if (trans->target2initiator_buffer_size) {
228 if (!send(split_trans_target2initiator_buffer(trans), trans->target2initiator_buffer_size)) {
229 *trans->status = TRANSACTION_DATA_ERROR;
230 return false;
231 }
232 }
233
234 *trans->status = TRANSACTION_ACCEPTED;
235 return true;
236}
237
238/**
239 * @brief Master specific initializations.
240 */
241void soft_serial_initiator_init(void) {
242 usart_master_init(&serial_driver);
243
244#if defined(MCU_STM32) && defined(SERIAL_USART_PIN_SWAP)
245 serial_config.cr2 |= USART_CR2_SWAP; // master has swapped TX/RX pins
246#endif
247
248 sdStart(serial_driver, &serial_config);
249}
250
251/**
252 * @brief Start transaction from the master half to the slave half.
253 *
254 * @param index Transaction Table index of the transaction to start.
255 * @return int TRANSACTION_NO_RESPONSE in case of Timeout.
256 * TRANSACTION_TYPE_ERROR in case of invalid transaction index.
257 * TRANSACTION_END in case of success.
258 */
259int soft_serial_transaction(int index) {
260 /* Clear the receive queue, to start with a clean slate.
261 * Parts of failed transactions or spurious bytes could still be in it. */
262 usart_clear();
263 return initiate_transaction((uint8_t)index);
264}
265
266/**
267 * @brief Initiate transaction to slave half.
268 */
269static inline int initiate_transaction(uint8_t sstd_index) {
270 /* Sanity check that we are actually starting a valid transaction. */
271 if (sstd_index >= NUM_TOTAL_TRANSACTIONS) {
272 dprintln("USART: Illegal transaction Id.");
273 return TRANSACTION_TYPE_ERROR;
274 }
275
276 split_transaction_desc_t* trans = &split_transaction_table[sstd_index];
277
278 /* Transaction is not registered. Abort. */
279 if (!trans->status) {
280 dprintln("USART: Transaction not registered.");
281 return TRANSACTION_TYPE_ERROR;
282 }
283
284 /* Send transaction table index to the slave, which doubles as basic handshake token. */
285 if (!send(&sstd_index, sizeof(sstd_index))) {
286 dprintln("USART: Send Handshake failed.");
287 return TRANSACTION_TYPE_ERROR;
288 }
289
290 uint8_t sstd_index_shake = 0xFF;
291
292 /* Which we always read back first so that we can error out correctly.
293 * - due to the half duplex limitations on return codes, we always have to read *something*.
294 * - without the read, write only transactions *always* succeed, even during the boot process where the slave is not ready.
295 */
296 if (!receive(&sstd_index_shake, sizeof(sstd_index_shake)) || (sstd_index_shake != (sstd_index ^ HANDSHAKE_MAGIC))) {
297 dprintln("USART: Handshake failed.");
298 return TRANSACTION_NO_RESPONSE;
299 }
300
301 /* Send transaction buffer to the slave. If this transaction requires it. */
302 if (trans->initiator2target_buffer_size) {
303 if (!send(split_trans_initiator2target_buffer(trans), trans->initiator2target_buffer_size)) {
304 dprintln("USART: Send failed.");
305 return TRANSACTION_NO_RESPONSE;
306 }
307 }
308
309 /* Receive transaction buffer from the slave. If this transaction requires it. */
310 if (trans->target2initiator_buffer_size) {
311 if (!receive(split_trans_target2initiator_buffer(trans), trans->target2initiator_buffer_size)) {
312 dprintln("USART: Receive failed.");
313 return TRANSACTION_NO_RESPONSE;
314 }
315 }
316
317 return TRANSACTION_END;
318}