1 /**
2 ******************************************************************************
3 * @file stm32g0xx_ll_usart.c
4 * @author MCD Application Team
5 * @brief USART LL module driver.
6 ******************************************************************************
7 * @attention
8 *
9 * Copyright (c) 2018 STMicroelectronics.
10 * All rights reserved.
11 *
12 * This software is licensed under terms that can be found in the LICENSE file
13 * in the root directory of this software component.
14 * If no LICENSE file comes with this software, it is provided AS-IS.
15 *
16 ******************************************************************************
17 */
18 #if defined(USE_FULL_LL_DRIVER)
19
20 /* Includes ------------------------------------------------------------------*/
21 #include "stm32g0xx_ll_usart.h"
22 #include "stm32g0xx_ll_rcc.h"
23 #include "stm32g0xx_ll_bus.h"
24 #ifdef USE_FULL_ASSERT
25 #include "stm32_assert.h"
26 #else
27 #define assert_param(expr) ((void)0U)
28 #endif /* USE_FULL_ASSERT */
29
30 /** @addtogroup STM32G0xx_LL_Driver
31 * @{
32 */
33
34 #if defined(USART1) || defined(USART2) || defined(USART3) || defined(USART4) || defined(USART5) || defined(USART6)
35
36 /** @addtogroup USART_LL
37 * @{
38 */
39
40 /* Private types -------------------------------------------------------------*/
41 /* Private variables ---------------------------------------------------------*/
42 /* Private constants ---------------------------------------------------------*/
43 /** @addtogroup USART_LL_Private_Constants
44 * @{
45 */
46
47 /* Definition of default baudrate value used for USART initialisation */
48 #define USART_DEFAULT_BAUDRATE (9600U)
49
50 /**
51 * @}
52 */
53
54 /* Private macros ------------------------------------------------------------*/
55 /** @addtogroup USART_LL_Private_Macros
56 * @{
57 */
58
59 #define IS_LL_USART_PRESCALER(__VALUE__) (((__VALUE__) == LL_USART_PRESCALER_DIV1) \
60 || ((__VALUE__) == LL_USART_PRESCALER_DIV2) \
61 || ((__VALUE__) == LL_USART_PRESCALER_DIV4) \
62 || ((__VALUE__) == LL_USART_PRESCALER_DIV6) \
63 || ((__VALUE__) == LL_USART_PRESCALER_DIV8) \
64 || ((__VALUE__) == LL_USART_PRESCALER_DIV10) \
65 || ((__VALUE__) == LL_USART_PRESCALER_DIV12) \
66 || ((__VALUE__) == LL_USART_PRESCALER_DIV16) \
67 || ((__VALUE__) == LL_USART_PRESCALER_DIV32) \
68 || ((__VALUE__) == LL_USART_PRESCALER_DIV64) \
69 || ((__VALUE__) == LL_USART_PRESCALER_DIV128) \
70 || ((__VALUE__) == LL_USART_PRESCALER_DIV256))
71
72 /* __BAUDRATE__ The maximum Baud Rate is derived from the maximum clock available
73 * divided by the smallest oversampling used on the USART (i.e. 8) */
74 #define IS_LL_USART_BAUDRATE(__BAUDRATE__) ((__BAUDRATE__) <= 8000000U)
75
76 /* __VALUE__ In case of oversampling by 16 and 8, BRR content must be greater than or equal to 16d. */
77 #define IS_LL_USART_BRR_MIN(__VALUE__) ((__VALUE__) >= 16U)
78
79 #define IS_LL_USART_DIRECTION(__VALUE__) (((__VALUE__) == LL_USART_DIRECTION_NONE) \
80 || ((__VALUE__) == LL_USART_DIRECTION_RX) \
81 || ((__VALUE__) == LL_USART_DIRECTION_TX) \
82 || ((__VALUE__) == LL_USART_DIRECTION_TX_RX))
83
84 #define IS_LL_USART_PARITY(__VALUE__) (((__VALUE__) == LL_USART_PARITY_NONE) \
85 || ((__VALUE__) == LL_USART_PARITY_EVEN) \
86 || ((__VALUE__) == LL_USART_PARITY_ODD))
87
88 #define IS_LL_USART_DATAWIDTH(__VALUE__) (((__VALUE__) == LL_USART_DATAWIDTH_7B) \
89 || ((__VALUE__) == LL_USART_DATAWIDTH_8B) \
90 || ((__VALUE__) == LL_USART_DATAWIDTH_9B))
91
92 #define IS_LL_USART_OVERSAMPLING(__VALUE__) (((__VALUE__) == LL_USART_OVERSAMPLING_16) \
93 || ((__VALUE__) == LL_USART_OVERSAMPLING_8))
94
95 #define IS_LL_USART_LASTBITCLKOUTPUT(__VALUE__) (((__VALUE__) == LL_USART_LASTCLKPULSE_NO_OUTPUT) \
96 || ((__VALUE__) == LL_USART_LASTCLKPULSE_OUTPUT))
97
98 #define IS_LL_USART_CLOCKPHASE(__VALUE__) (((__VALUE__) == LL_USART_PHASE_1EDGE) \
99 || ((__VALUE__) == LL_USART_PHASE_2EDGE))
100
101 #define IS_LL_USART_CLOCKPOLARITY(__VALUE__) (((__VALUE__) == LL_USART_POLARITY_LOW) \
102 || ((__VALUE__) == LL_USART_POLARITY_HIGH))
103
104 #define IS_LL_USART_CLOCKOUTPUT(__VALUE__) (((__VALUE__) == LL_USART_CLOCK_DISABLE) \
105 || ((__VALUE__) == LL_USART_CLOCK_ENABLE))
106
107 #define IS_LL_USART_STOPBITS(__VALUE__) (((__VALUE__) == LL_USART_STOPBITS_0_5) \
108 || ((__VALUE__) == LL_USART_STOPBITS_1) \
109 || ((__VALUE__) == LL_USART_STOPBITS_1_5) \
110 || ((__VALUE__) == LL_USART_STOPBITS_2))
111
112 #define IS_LL_USART_HWCONTROL(__VALUE__) (((__VALUE__) == LL_USART_HWCONTROL_NONE) \
113 || ((__VALUE__) == LL_USART_HWCONTROL_RTS) \
114 || ((__VALUE__) == LL_USART_HWCONTROL_CTS) \
115 || ((__VALUE__) == LL_USART_HWCONTROL_RTS_CTS))
116
117 /**
118 * @}
119 */
120
121 /* Private function prototypes -----------------------------------------------*/
122
123 /* Exported functions --------------------------------------------------------*/
124 /** @addtogroup USART_LL_Exported_Functions
125 * @{
126 */
127
128 /** @addtogroup USART_LL_EF_Init
129 * @{
130 */
131
132 /**
133 * @brief De-initialize USART registers (Registers restored to their default values).
134 * @param USARTx USART Instance
135 * @retval An ErrorStatus enumeration value:
136 * - SUCCESS: USART registers are de-initialized
137 * - ERROR: USART registers are not de-initialized
138 */
LL_USART_DeInit(const USART_TypeDef * USARTx)139 ErrorStatus LL_USART_DeInit(const USART_TypeDef *USARTx)
140 {
141 ErrorStatus status = SUCCESS;
142
143 /* Check the parameters */
144 assert_param(IS_UART_INSTANCE(USARTx));
145
146 if (USARTx == USART1)
147 {
148 /* Force reset of USART clock */
149 LL_APB2_GRP1_ForceReset(LL_APB2_GRP1_PERIPH_USART1);
150
151 /* Release reset of USART clock */
152 LL_APB2_GRP1_ReleaseReset(LL_APB2_GRP1_PERIPH_USART1);
153 }
154 else if (USARTx == USART2)
155 {
156 /* Force reset of USART clock */
157 LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART2);
158
159 /* Release reset of USART clock */
160 LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART2);
161 }
162 #if defined(USART3)
163 else if (USARTx == USART3)
164 {
165 /* Force reset of USART clock */
166 LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART3);
167
168 /* Release reset of USART clock */
169 LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART3);
170 }
171 #endif /* USART3 */
172 #if defined(USART4)
173 else if (USARTx == USART4)
174 {
175 /* Force reset of USART clock */
176 LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART4);
177
178 /* Release reset of USART clock */
179 LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART4);
180 }
181 #endif /* USART4 */
182 #if defined(USART5)
183 else if (USARTx == USART5)
184 {
185 /* Force reset of USART clock */
186 LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART5);
187
188 /* Release reset of USART clock */
189 LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART5);
190 }
191 #endif /* USART5 */
192 #if defined(USART6)
193 else if (USARTx == USART6)
194 {
195 /* Force reset of USART clock */
196 LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART6);
197
198 /* Release reset of USART clock */
199 LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART6);
200 }
201 #endif /* USART6 */
202 else
203 {
204 status = ERROR;
205 }
206
207 return (status);
208 }
209
210 /**
211 * @brief Initialize USART registers according to the specified
212 * parameters in USART_InitStruct.
213 * @note As some bits in USART configuration registers can only be written when
214 * the USART is disabled (USART_CR1_UE bit =0), USART Peripheral should be in disabled state prior calling
215 * this function. Otherwise, ERROR result will be returned.
216 * @note Baud rate value stored in USART_InitStruct BaudRate field, should be valid (different from 0).
217 * @param USARTx USART Instance
218 * @param USART_InitStruct pointer to a LL_USART_InitTypeDef structure
219 * that contains the configuration information for the specified USART peripheral.
220 * @retval An ErrorStatus enumeration value:
221 * - SUCCESS: USART registers are initialized according to USART_InitStruct content
222 * - ERROR: Problem occurred during USART Registers initialization
223 */
LL_USART_Init(USART_TypeDef * USARTx,const LL_USART_InitTypeDef * USART_InitStruct)224 ErrorStatus LL_USART_Init(USART_TypeDef *USARTx, const LL_USART_InitTypeDef *USART_InitStruct)
225 {
226 ErrorStatus status = ERROR;
227 uint32_t periphclk = LL_RCC_PERIPH_FREQUENCY_NO;
228 #if !defined(RCC_CCIPR_USART3SEL)&&!defined(RCC_CCIPR_USART4SEL)||(!defined(RCC_CCIPR_USART2SEL))||!defined(RCC_CCIPR_USART5SEL)||!defined(RCC_CCIPR_USART6SEL)
229 LL_RCC_ClocksTypeDef RCC_Clocks;
230 #endif /* USART clock selection flags */
231
232 /* Check the parameters */
233 assert_param(IS_UART_INSTANCE(USARTx));
234 assert_param(IS_LL_USART_PRESCALER(USART_InitStruct->PrescalerValue));
235 assert_param(IS_LL_USART_BAUDRATE(USART_InitStruct->BaudRate));
236 assert_param(IS_LL_USART_DATAWIDTH(USART_InitStruct->DataWidth));
237 assert_param(IS_LL_USART_STOPBITS(USART_InitStruct->StopBits));
238 assert_param(IS_LL_USART_PARITY(USART_InitStruct->Parity));
239 assert_param(IS_LL_USART_DIRECTION(USART_InitStruct->TransferDirection));
240 assert_param(IS_LL_USART_HWCONTROL(USART_InitStruct->HardwareFlowControl));
241 assert_param(IS_LL_USART_OVERSAMPLING(USART_InitStruct->OverSampling));
242
243 /* USART needs to be in disabled state, in order to be able to configure some bits in
244 CRx registers */
245 if (LL_USART_IsEnabled(USARTx) == 0U)
246 {
247 /*---------------------------- USART CR1 Configuration ---------------------
248 * Configure USARTx CR1 (USART Word Length, Parity, Mode and Oversampling bits) with parameters:
249 * - DataWidth: USART_CR1_M bits according to USART_InitStruct->DataWidth value
250 * - Parity: USART_CR1_PCE, USART_CR1_PS bits according to USART_InitStruct->Parity value
251 * - TransferDirection: USART_CR1_TE, USART_CR1_RE bits according to USART_InitStruct->TransferDirection value
252 * - Oversampling: USART_CR1_OVER8 bit according to USART_InitStruct->OverSampling value.
253 */
254 MODIFY_REG(USARTx->CR1,
255 (USART_CR1_M | USART_CR1_PCE | USART_CR1_PS |
256 USART_CR1_TE | USART_CR1_RE | USART_CR1_OVER8),
257 (USART_InitStruct->DataWidth | USART_InitStruct->Parity |
258 USART_InitStruct->TransferDirection | USART_InitStruct->OverSampling));
259
260 /*---------------------------- USART CR2 Configuration ---------------------
261 * Configure USARTx CR2 (Stop bits) with parameters:
262 * - Stop Bits: USART_CR2_STOP bits according to USART_InitStruct->StopBits value.
263 * - CLKEN, CPOL, CPHA and LBCL bits are to be configured using LL_USART_ClockInit().
264 */
265 LL_USART_SetStopBitsLength(USARTx, USART_InitStruct->StopBits);
266
267 /*---------------------------- USART CR3 Configuration ---------------------
268 * Configure USARTx CR3 (Hardware Flow Control) with parameters:
269 * - HardwareFlowControl: USART_CR3_RTSE, USART_CR3_CTSE bits according to
270 * USART_InitStruct->HardwareFlowControl value.
271 */
272 LL_USART_SetHWFlowCtrl(USARTx, USART_InitStruct->HardwareFlowControl);
273
274 /*---------------------------- USART BRR Configuration ---------------------
275 * Retrieve Clock frequency used for USART Peripheral
276 */
277 if (USARTx == USART1)
278 {
279 periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART1_CLKSOURCE);
280 }
281 else if (USARTx == USART2)
282 {
283 #if defined(RCC_CCIPR_USART2SEL)
284 periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART2_CLKSOURCE);
285 #else
286 /* USART2 clock is PCLK */
287 LL_RCC_GetSystemClocksFreq(&RCC_Clocks);
288 periphclk = RCC_Clocks.PCLK1_Frequency;
289 #endif /* USART2 Clock selector flag */
290 }
291 #if defined(USART3)
292 else if (USARTx == USART3)
293 {
294 #if defined(RCC_CCIPR_USART3SEL)
295 periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART3_CLKSOURCE);
296 #else
297 /* USART3 clock is PCLK */
298 LL_RCC_GetSystemClocksFreq(&RCC_Clocks);
299 periphclk = RCC_Clocks.PCLK1_Frequency;
300 #endif /* USART3 Clock selector flag */
301 }
302 #endif /* USART3 */
303 #if defined(USART4)
304 else if (USARTx == USART4)
305 {
306 #if defined(RCC_CCIPR_USART4SEL)
307 periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART4_CLKSOURCE);
308 #else
309 /* USART4 clock is PCLK1 */
310 LL_RCC_GetSystemClocksFreq(&RCC_Clocks);
311 periphclk = RCC_Clocks.PCLK1_Frequency;
312 #endif /* RCC_CCIPR_USART4SEL */
313 }
314 #endif /* USART4 */
315 #if defined(USART5)
316 else if (USARTx == USART5)
317 {
318 /* USART5 clock is PCLK1 */
319 LL_RCC_GetSystemClocksFreq(&RCC_Clocks);
320 periphclk = RCC_Clocks.PCLK1_Frequency;
321 }
322 #endif /* USART5 */
323 #if defined(USART6)
324 else if (USARTx == USART6)
325 {
326 /* USART6 clock is PCLK1 */
327 LL_RCC_GetSystemClocksFreq(&RCC_Clocks);
328 periphclk = RCC_Clocks.PCLK1_Frequency;
329 }
330 #endif /* USART6 */
331 else
332 {
333 /* Nothing to do, as error code is already assigned to ERROR value */
334 }
335
336 /* Configure the USART Baud Rate :
337 - prescaler value is required
338 - valid baud rate value (different from 0) is required
339 - Peripheral clock as returned by RCC service, should be valid (different from 0).
340 */
341 if ((periphclk != LL_RCC_PERIPH_FREQUENCY_NO)
342 && (USART_InitStruct->BaudRate != 0U))
343 {
344 status = SUCCESS;
345 LL_USART_SetBaudRate(USARTx,
346 periphclk,
347 USART_InitStruct->PrescalerValue,
348 USART_InitStruct->OverSampling,
349 USART_InitStruct->BaudRate);
350
351 /* Check BRR is greater than or equal to 16d */
352 assert_param(IS_LL_USART_BRR_MIN(USARTx->BRR));
353 }
354
355 /*---------------------------- USART PRESC Configuration -----------------------
356 * Configure USARTx PRESC (Prescaler) with parameters:
357 * - PrescalerValue: USART_PRESC_PRESCALER bits according to USART_InitStruct->PrescalerValue value.
358 */
359 LL_USART_SetPrescaler(USARTx, USART_InitStruct->PrescalerValue);
360 }
361 /* Endif (=> USART not in Disabled state => return ERROR) */
362
363 return (status);
364 }
365
366 /**
367 * @brief Set each @ref LL_USART_InitTypeDef field to default value.
368 * @param USART_InitStruct pointer to a @ref LL_USART_InitTypeDef structure
369 * whose fields will be set to default values.
370 * @retval None
371 */
372
LL_USART_StructInit(LL_USART_InitTypeDef * USART_InitStruct)373 void LL_USART_StructInit(LL_USART_InitTypeDef *USART_InitStruct)
374 {
375 /* Set USART_InitStruct fields to default values */
376 USART_InitStruct->PrescalerValue = LL_USART_PRESCALER_DIV1;
377 USART_InitStruct->BaudRate = USART_DEFAULT_BAUDRATE;
378 USART_InitStruct->DataWidth = LL_USART_DATAWIDTH_8B;
379 USART_InitStruct->StopBits = LL_USART_STOPBITS_1;
380 USART_InitStruct->Parity = LL_USART_PARITY_NONE ;
381 USART_InitStruct->TransferDirection = LL_USART_DIRECTION_TX_RX;
382 USART_InitStruct->HardwareFlowControl = LL_USART_HWCONTROL_NONE;
383 USART_InitStruct->OverSampling = LL_USART_OVERSAMPLING_16;
384 }
385
386 /**
387 * @brief Initialize USART Clock related settings according to the
388 * specified parameters in the USART_ClockInitStruct.
389 * @note As some bits in USART configuration registers can only be written when
390 * the USART is disabled (USART_CR1_UE bit =0), USART Peripheral should be in disabled state prior calling
391 * this function. Otherwise, ERROR result will be returned.
392 * @param USARTx USART Instance
393 * @param USART_ClockInitStruct pointer to a @ref LL_USART_ClockInitTypeDef structure
394 * that contains the Clock configuration information for the specified USART peripheral.
395 * @retval An ErrorStatus enumeration value:
396 * - SUCCESS: USART registers related to Clock settings are initialized according
397 * to USART_ClockInitStruct content
398 * - ERROR: Problem occurred during USART Registers initialization
399 */
LL_USART_ClockInit(USART_TypeDef * USARTx,const LL_USART_ClockInitTypeDef * USART_ClockInitStruct)400 ErrorStatus LL_USART_ClockInit(USART_TypeDef *USARTx, const LL_USART_ClockInitTypeDef *USART_ClockInitStruct)
401 {
402 ErrorStatus status = SUCCESS;
403
404 /* Check USART Instance and Clock signal output parameters */
405 assert_param(IS_UART_INSTANCE(USARTx));
406 assert_param(IS_LL_USART_CLOCKOUTPUT(USART_ClockInitStruct->ClockOutput));
407
408 /* USART needs to be in disabled state, in order to be able to configure some bits in
409 CRx registers */
410 if (LL_USART_IsEnabled(USARTx) == 0U)
411 {
412 /* Ensure USART instance is USART capable */
413 assert_param(IS_USART_INSTANCE(USARTx));
414
415 /* Check clock related parameters */
416 assert_param(IS_LL_USART_CLOCKPOLARITY(USART_ClockInitStruct->ClockPolarity));
417 assert_param(IS_LL_USART_CLOCKPHASE(USART_ClockInitStruct->ClockPhase));
418 assert_param(IS_LL_USART_LASTBITCLKOUTPUT(USART_ClockInitStruct->LastBitClockPulse));
419
420 /*---------------------------- USART CR2 Configuration -----------------------
421 * Configure USARTx CR2 (Clock signal related bits) with parameters:
422 * - Clock Output: USART_CR2_CLKEN bit according to USART_ClockInitStruct->ClockOutput value
423 * - Clock Polarity: USART_CR2_CPOL bit according to USART_ClockInitStruct->ClockPolarity value
424 * - Clock Phase: USART_CR2_CPHA bit according to USART_ClockInitStruct->ClockPhase value
425 * - Last Bit Clock Pulse Output: USART_CR2_LBCL bit according to USART_ClockInitStruct->LastBitClockPulse value.
426 */
427 MODIFY_REG(USARTx->CR2,
428 USART_CR2_CLKEN | USART_CR2_CPHA | USART_CR2_CPOL | USART_CR2_LBCL,
429 USART_ClockInitStruct->ClockOutput | USART_ClockInitStruct->ClockPolarity |
430 USART_ClockInitStruct->ClockPhase | USART_ClockInitStruct->LastBitClockPulse);
431 }
432 /* Else (USART not in Disabled state => return ERROR */
433 else
434 {
435 status = ERROR;
436 }
437
438 return (status);
439 }
440
441 /**
442 * @brief Set each field of a @ref LL_USART_ClockInitTypeDef type structure to default value.
443 * @param USART_ClockInitStruct pointer to a @ref LL_USART_ClockInitTypeDef structure
444 * whose fields will be set to default values.
445 * @retval None
446 */
LL_USART_ClockStructInit(LL_USART_ClockInitTypeDef * USART_ClockInitStruct)447 void LL_USART_ClockStructInit(LL_USART_ClockInitTypeDef *USART_ClockInitStruct)
448 {
449 /* Set LL_USART_ClockInitStruct fields with default values */
450 USART_ClockInitStruct->ClockOutput = LL_USART_CLOCK_DISABLE;
451 USART_ClockInitStruct->ClockPolarity = LL_USART_POLARITY_LOW; /* Not relevant when ClockOutput =
452 LL_USART_CLOCK_DISABLE */
453 USART_ClockInitStruct->ClockPhase = LL_USART_PHASE_1EDGE; /* Not relevant when ClockOutput =
454 LL_USART_CLOCK_DISABLE */
455 USART_ClockInitStruct->LastBitClockPulse = LL_USART_LASTCLKPULSE_NO_OUTPUT; /* Not relevant when ClockOutput =
456 LL_USART_CLOCK_DISABLE */
457 }
458
459 /**
460 * @}
461 */
462
463 /**
464 * @}
465 */
466
467 /**
468 * @}
469 */
470
471 #endif /* USART1 || USART2 || USART3 || USART4 || USART5 || USART6 */
472
473 /**
474 * @}
475 */
476
477 #endif /* USE_FULL_LL_DRIVER */
478
479
