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   1 /*
   2  * Copyright © 2012 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  */
  17
  18 #include <ao.h>
  19
  20 struct ao_stm_usart {
  21         struct ao_fifo          rx_fifo;
  22         struct ao_fifo          tx_fifo;
  23         struct stm_usart        *reg;
  24         uint8_t                 tx_started;
  25 };
  26
  27 void
  28 ao_debug_out(char c)
  29 {
  30         if (c == '\n')
  31                 ao_debug_out('\r');
  32         while (!(stm_usart1.sr & (1 << STM_USART_SR_TXE)));
  33         stm_usart1.dr = c;
  34 }
  35
  36 static void
  37 _ao_usart_tx_start(struct ao_stm_usart *usart)
  38 {
  39         if (!ao_fifo_empty(usart->tx_fifo) && !usart->tx_started)
  40         {
  41                 usart->tx_started = 1;
  42                 ao_fifo_remove(usart->tx_fifo, usart->reg->dr);
  43         }
  44 }
  45
  46 static void
  47 ao_usart_isr(struct ao_stm_usart *usart, int stdin)
  48 {
  49         uint32_t        sr;
  50
  51         sr = usart->reg->sr;
  52         usart->reg->sr = 0;
  53
  54         if (sr & (1 << STM_USART_SR_RXNE)) {
  55                 char c = usart->reg->dr;
  56                 if (!ao_fifo_full(usart->rx_fifo))
  57                         ao_fifo_insert(usart->rx_fifo, c);
  58                 ao_wakeup(&usart->rx_fifo);
  59                 if (stdin)
  60                         ao_wakeup(&ao_stdin_ready);
  61         }
  62         if (sr & (1 << STM_USART_SR_TC)) {
  63                 usart->tx_started = 0;
  64                 _ao_usart_tx_start(usart);
  65                 ao_wakeup(&usart->tx_fifo);
  66         }
  67 }
  68
  69 char
  70 ao_usart_getchar(struct ao_stm_usart *usart)
  71 {
  72         char c;
  73         ao_arch_block_interrupts();
  74         while (ao_fifo_empty(usart->rx_fifo))
  75                 ao_sleep(&usart->rx_fifo);
  76         ao_fifo_remove(usart->rx_fifo, c);
  77         ao_arch_release_interrupts();
  78         return c;
  79 }
  80
  81 char
  82 ao_usart_pollchar(struct ao_stm_usart *usart)
  83 {
  84         char    c;
  85
  86         ao_arch_block_interrupts();
  87         if (ao_fifo_empty(usart->rx_fifo))
  88                 c = AO_READ_AGAIN;
  89         else
  90                 ao_fifo_remove(usart->rx_fifo,c);
  91         ao_arch_release_interrupts();
  92         return c;
  93 }
  94
  95 void
  96 ao_usart_putchar(struct ao_stm_usart *usart, char c)
  97 {
  98         ao_arch_block_interrupts();
  99         while (ao_fifo_full(usart->tx_fifo))
 100                 ao_sleep(&usart->tx_fifo);
 101         ao_fifo_insert(usart->tx_fifo, c);
 102         _ao_usart_tx_start(usart);
 103         ao_arch_release_interrupts();
 104 }
 105
 106 void
 107 ao_usart_drain(struct ao_stm_usart *usart)
 108 {
 109         ao_arch_block_interrupts();
 110         while (!ao_fifo_empty(usart->tx_fifo))
 111                 ao_sleep(&usart->tx_fifo);
 112         ao_arch_release_interrupts();
 113 }
 114
 115 static const struct {
 116         uint32_t brr;
 117 } ao_usart_speeds[] = {
 118         [AO_SERIAL_SPEED_4800] = {
 119                 AO_PCLK1 / 4800
 120         },
 121         [AO_SERIAL_SPEED_9600] = {
 122                 AO_PCLK1 / 9600
 123         },
 124         [AO_SERIAL_SPEED_19200] = {
 125                 AO_PCLK1 / 19200
 126         },
 127         [AO_SERIAL_SPEED_57600] = {
 128                 AO_PCLK1 / 57600
 129         },
 130 };
 131
 132 void
 133 ao_usart_set_speed(struct ao_stm_usart *usart, uint8_t speed)
 134 {
 135         if (speed > AO_SERIAL_SPEED_57600)
 136                 return;
 137         usart->reg->brr = ao_usart_speeds[speed].brr;
 138 }
 139
 140 void
 141 ao_usart_init(struct ao_stm_usart *usart)
 142 {
 143         usart->reg->cr1 = ((0 << STM_USART_CR1_OVER8) |
 144                           (1 << STM_USART_CR1_UE) |
 145                           (0 << STM_USART_CR1_M) |
 146                           (0 << STM_USART_CR1_WAKE) |
 147                           (0 << STM_USART_CR1_PCE) |
 148                           (0 << STM_USART_CR1_PS) |
 149                           (0 << STM_USART_CR1_PEIE) |
 150                           (0 << STM_USART_CR1_TXEIE) |
 151                           (1 << STM_USART_CR1_TCIE) |
 152                           (1 << STM_USART_CR1_RXNEIE) |
 153                           (0 << STM_USART_CR1_IDLEIE) |
 154                           (1 << STM_USART_CR1_TE) |
 155                           (1 << STM_USART_CR1_RE) |
 156                           (0 << STM_USART_CR1_RWU) |
 157                           (0 << STM_USART_CR1_SBK));
 158
 159         usart->reg->cr2 = ((0 << STM_USART_CR2_LINEN) |
 160                           (STM_USART_CR2_STOP_1 << STM_USART_CR2_STOP) |
 161                           (0 << STM_USART_CR2_CLKEN) |
 162                           (0 << STM_USART_CR2_CPOL) |
 163                           (0 << STM_USART_CR2_CPHA) |
 164                           (0 << STM_USART_CR2_LBCL) |
 165                           (0 << STM_USART_CR2_LBDIE) |
 166                           (0 << STM_USART_CR2_LBDL) |
 167                           (0 << STM_USART_CR2_ADD));
 168
 169         usart->reg->cr3 = ((0 << STM_USART_CR3_ONEBITE) |
 170                           (0 << STM_USART_CR3_CTSIE) |
 171                           (0 << STM_USART_CR3_CTSE) |
 172                           (0 << STM_USART_CR3_RTSE) |
 173                           (0 << STM_USART_CR3_DMAT) |
 174                           (0 << STM_USART_CR3_DMAR) |
 175                           (0 << STM_USART_CR3_SCEN) |
 176                           (0 << STM_USART_CR3_NACK) |
 177                           (0 << STM_USART_CR3_HDSEL) |
 178                           (0 << STM_USART_CR3_IRLP) |
 179                           (0 << STM_USART_CR3_IREN) |
 180                           (0 << STM_USART_CR3_EIE));
 181
 182         /* Pick a 9600 baud rate */
 183         ao_usart_set_speed(usart, AO_SERIAL_SPEED_9600);
 184 }
 185
 186 #if HAS_SERIAL_1
 187
 188 struct ao_stm_usart ao_stm_usart1;
 189
 190 void stm_usart1_isr(void) { ao_usart_isr(&ao_stm_usart1, USE_SERIAL_1_STDIN); }
 191
 192 char
 193 ao_serial1_getchar(void)
 194 {
 195         return ao_usart_getchar(&ao_stm_usart1);
 196 }
 197
 198 void
 199 ao_serial1_putchar(char c)
 200 {
 201         ao_usart_putchar(&ao_stm_usart1, c);
 202 }
 203
 204 char
 205 ao_serial1_pollchar(void)
 206 {
 207         return ao_usart_pollchar(&ao_stm_usart1);
 208 }
 209
 210 void
 211 ao_serial1_set_speed(uint8_t speed)
 212 {
 213         ao_usart_set_speed(&ao_stm_usart1, speed);
 214 }
 215 #endif  /* HAS_SERIAL_1 */
 216
 217 #if HAS_SERIAL_2
 218
 219 struct ao_stm_usart ao_stm_usart2;
 220
 221 void stm_usart2_isr(void) { ao_usart_isr(&ao_stm_usart2, USE_SERIAL_2_STDIN); }
 222
 223 char
 224 ao_serial2_getchar(void)
 225 {
 226         return ao_usart_getchar(&ao_stm_usart2);
 227 }
 228
 229 void
 230 ao_serial2_putchar(char c)
 231 {
 232         ao_usart_putchar(&ao_stm_usart2, c);
 233 }
 234
 235 char
 236 ao_serial2_pollchar(void)
 237 {
 238         return ao_usart_pollchar(&ao_stm_usart2);
 239 }
 240
 241 void
 242 ao_serial2_set_speed(uint8_t speed)
 243 {
 244         ao_usart_set_speed(&ao_stm_usart2, speed);
 245 }
 246 #endif  /* HAS_SERIAL_2 */
 247
 248 #if HAS_SERIAL_3
 249
 250 struct ao_stm_usart ao_stm_usart3;
 251
 252 void stm_usart3_isr(void) { ao_usart_isr(&ao_stm_usart3, USE_SERIAL_2_STDIN); }
 253
 254 char
 255 ao_serial3_getchar(void)
 256 {
 257         return ao_usart_getchar(&ao_stm_usart3);
 258 }
 259
 260 void
 261 ao_serial3_putchar(char c)
 262 {
 263         ao_usart_putchar(&ao_stm_usart3, c);
 264 }
 265
 266 char
 267 ao_serial3_pollchar(void)
 268 {
 269         return ao_usart_pollchar(&ao_stm_usart3);
 270 }
 271
 272 void
 273 ao_serial3_set_speed(uint8_t speed)
 274 {
 275         ao_usart_set_speed(&ao_stm_usart3, speed);
 276 }
 277 #endif  /* HAS_SERIAL_3 */
 278
 279 void
 280 ao_serial_init(void)
 281 {
 282 #if HAS_SERIAL_1
 283         /*
 284          *      TX      RX
 285          *      PA9     PA10
 286          *      PB6     PB7     *
 287          */
 288
 289 #if SERIAL_1_PA9_PA10
 290         stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOAEN);
 291
 292         stm_afr_set(&stm_gpioa, 9, STM_AFR_AF7);
 293         stm_afr_set(&stm_gpioa, 10, STM_AFR_AF7);
 294 #else
 295 #if SERIAL_1_PB6_PB7
 296         stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOBEN);
 297
 298         stm_afr_set(&stm_gpiob, 6, STM_AFR_AF7);
 299         stm_afr_set(&stm_gpiob, 7, STM_AFR_AF7);
 300 #else
 301 #error "No SERIAL_1 port configuration specified"
 302 #endif
 303 #endif
 304         /* Enable USART */
 305         stm_rcc.apb2enr |= (1 << STM_RCC_APB2ENR_USART1EN);
 306
 307         ao_stm_usart1.reg = &stm_usart1;
 308         ao_usart_init(&ao_stm_usart1);
 309
 310         stm_nvic_set_enable(STM_ISR_USART1_POS);
 311         stm_nvic_set_priority(STM_ISR_USART1_POS, 4);
 312 #if USE_SERIAL_1_STDIN
 313         ao_add_stdio(ao_serial1_pollchar,
 314                      ao_serial1_putchar,
 315                      NULL);
 316 #endif
 317 #endif
 318
 319 #if HAS_SERIAL_2
 320         /*
 321          *      TX      RX
 322          *      PA2     PA3
 323          *      PD5     PD6
 324          */
 325
 326 #if SERIAL_2_PA2_PA3
 327         stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOAEN);
 328
 329         stm_afr_set(&stm_gpioa, 2, STM_AFR_AF7);
 330         stm_afr_set(&stm_gpioa, 3, STM_AFR_AF7);
 331 #else
 332 #if SERIAL_2_PD5_PD6
 333         stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIODEN);
 334
 335         stm_afr_set(&stm_gpiod, 5, STM_AFR_AF7);
 336         stm_afr_set(&stm_gpiod, 6, STM_AFR_AF7);
 337 #else
 338 #error "No SERIAL_2 port configuration specified"
 339 #endif
 340 #endif
 341         /* Enable USART */
 342         stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_USART2EN);
 343
 344         ao_stm_usart2.reg = &stm_usart2;
 345         ao_usart_init(&ao_stm_usart2);
 346
 347         stm_nvic_set_enable(STM_ISR_USART2_POS);
 348         stm_nvic_set_priority(STM_ISR_USART2_POS, 4);
 349 #if USE_SERIAL_2_STDIN
 350         ao_add_stdio(ao_serial2_pollchar,
 351                      ao_serial2_putchar,
 352                      NULL);
 353 #endif
 354 #endif
 355
 356 #if HAS_SERIAL_3
 357         /*
 358          *      TX      RX
 359          *      PB10    PB11
 360          *      PC10    PC11
 361          *      PD8     PD9
 362          */
 363 #if SERIAL_3_PB10_PB11
 364         stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOBEN);
 365
 366         stm_afr_set(&stm_gpiob, 10, STM_AFR_AF7);
 367         stm_afr_set(&stm_gpiob, 11, STM_AFR_AF7);
 368 #else
 369 #if SERIAL_3_PC10_PC11
 370         stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOCEN);
 371
 372         stm_afr_set(&stm_gpioc, 10, STM_AFR_AF7);
 373         stm_afr_set(&stm_gpioc, 11, STM_AFR_AF7);
 374 #else
 375 #if SERIAL_3_PD8_PD9
 376         stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIODEN);
 377
 378         stm_afr_set(&stm_gpiod, 8, STM_AFR_AF7);
 379         stm_afr_set(&stm_gpiod, 9, STM_AFR_AF7);
 380 #else
 381 #error "No SERIAL_3 port configuration specified"
 382 #endif
 383 #endif
 384 #endif
 385         /* Enable USART */
 386         stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_USART3EN);
 387
 388         ao_stm_usart3.reg = &stm_usart3;
 389         ao_usart_init(&ao_stm_usart3);
 390
 391         stm_nvic_set_enable(STM_ISR_USART3_POS);
 392         stm_nvic_set_priority(STM_ISR_USART3_POS, 4);
 393 #if USE_SERIAL_3_STDIN
 394         ao_add_stdio(ao_serial3_pollchar,
 395                      ao_serial3_putchar,
 396                      NULL);
 397 #endif
 398 #endif
 399 }
 400
 401