1 /**
2 ******************************************************************************
3 * @file stm32l5xx_ll_usart.c
4 * @author MCD Application Team
5 * @brief USART LL module driver.
6 ******************************************************************************
7 * @attention
8 *
9 * Copyright (c) 2019 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 "stm32l5xx_ll_usart.h"
22 #include "stm32l5xx_ll_rcc.h"
23 #include "stm32l5xx_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 STM32L5xx_LL_Driver
31 * @{
32 */
33
34 #if defined(USART1) || defined(USART2) || defined(USART3) || defined(UART4) || defined(UART5)
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__) <= 15000000U)
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 else if (USARTx == USART3)
163 {
164 /* Force reset of USART clock */
165 LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART3);
166
167 /* Release reset of USART clock */
168 LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART3);
169 }
170 else if (USARTx == UART4)
171 {
172 /* Force reset of UART clock */
173 LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_UART4);
174
175 /* Release reset of UART clock */
176 LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_UART4);
177 }
178 else if (USARTx == UART5)
179 {
180 /* Force reset of UART clock */
181 LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_UART5);
182
183 /* Release reset of UART clock */
184 LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_UART5);
185 }
186 else
187 {
188 status = ERROR;
189 }
190
191 return (status);
192 }
193
194 /**
195 * @brief Initialize USART registers according to the specified
196 * parameters in USART_InitStruct.
197 * @note As some bits in USART configuration registers can only be written when
198 * the USART is disabled (USART_CR1_UE bit =0), USART Peripheral should be in disabled state prior calling
199 * this function. Otherwise, ERROR result will be returned.
200 * @note Baud rate value stored in USART_InitStruct BaudRate field, should be valid (different from 0).
201 * @param USARTx USART Instance
202 * @param USART_InitStruct pointer to a LL_USART_InitTypeDef structure
203 * that contains the configuration information for the specified USART peripheral.
204 * @retval An ErrorStatus enumeration value:
205 * - SUCCESS: USART registers are initialized according to USART_InitStruct content
206 * - ERROR: Problem occurred during USART Registers initialization
207 */
LL_USART_Init(USART_TypeDef * USARTx,const LL_USART_InitTypeDef * USART_InitStruct)208 ErrorStatus LL_USART_Init(USART_TypeDef *USARTx, const LL_USART_InitTypeDef *USART_InitStruct)
209 {
210 ErrorStatus status = ERROR;
211 uint32_t periphclk = LL_RCC_PERIPH_FREQUENCY_NO;
212
213 /* Check the parameters */
214 assert_param(IS_UART_INSTANCE(USARTx));
215 assert_param(IS_LL_USART_PRESCALER(USART_InitStruct->PrescalerValue));
216 assert_param(IS_LL_USART_BAUDRATE(USART_InitStruct->BaudRate));
217 assert_param(IS_LL_USART_DATAWIDTH(USART_InitStruct->DataWidth));
218 assert_param(IS_LL_USART_STOPBITS(USART_InitStruct->StopBits));
219 assert_param(IS_LL_USART_PARITY(USART_InitStruct->Parity));
220 assert_param(IS_LL_USART_DIRECTION(USART_InitStruct->TransferDirection));
221 assert_param(IS_LL_USART_HWCONTROL(USART_InitStruct->HardwareFlowControl));
222 assert_param(IS_LL_USART_OVERSAMPLING(USART_InitStruct->OverSampling));
223
224 /* USART needs to be in disabled state, in order to be able to configure some bits in
225 CRx registers */
226 if (LL_USART_IsEnabled(USARTx) == 0U)
227 {
228 /*---------------------------- USART CR1 Configuration ---------------------
229 * Configure USARTx CR1 (USART Word Length, Parity, Mode and Oversampling bits) with parameters:
230 * - DataWidth: USART_CR1_M bits according to USART_InitStruct->DataWidth value
231 * - Parity: USART_CR1_PCE, USART_CR1_PS bits according to USART_InitStruct->Parity value
232 * - TransferDirection: USART_CR1_TE, USART_CR1_RE bits according to USART_InitStruct->TransferDirection value
233 * - Oversampling: USART_CR1_OVER8 bit according to USART_InitStruct->OverSampling value.
234 */
235 MODIFY_REG(USARTx->CR1,
236 (USART_CR1_M | USART_CR1_PCE | USART_CR1_PS |
237 USART_CR1_TE | USART_CR1_RE | USART_CR1_OVER8),
238 (USART_InitStruct->DataWidth | USART_InitStruct->Parity |
239 USART_InitStruct->TransferDirection | USART_InitStruct->OverSampling));
240
241 /*---------------------------- USART CR2 Configuration ---------------------
242 * Configure USARTx CR2 (Stop bits) with parameters:
243 * - Stop Bits: USART_CR2_STOP bits according to USART_InitStruct->StopBits value.
244 * - CLKEN, CPOL, CPHA and LBCL bits are to be configured using LL_USART_ClockInit().
245 */
246 LL_USART_SetStopBitsLength(USARTx, USART_InitStruct->StopBits);
247
248 /*---------------------------- USART CR3 Configuration ---------------------
249 * Configure USARTx CR3 (Hardware Flow Control) with parameters:
250 * - HardwareFlowControl: USART_CR3_RTSE, USART_CR3_CTSE bits according to
251 * USART_InitStruct->HardwareFlowControl value.
252 */
253 LL_USART_SetHWFlowCtrl(USARTx, USART_InitStruct->HardwareFlowControl);
254
255 /*---------------------------- USART BRR Configuration ---------------------
256 * Retrieve Clock frequency used for USART Peripheral
257 */
258 if (USARTx == USART1)
259 {
260 periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART1_CLKSOURCE);
261 }
262 else if (USARTx == USART2)
263 {
264 periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART2_CLKSOURCE);
265 }
266 else if (USARTx == USART3)
267 {
268 periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART3_CLKSOURCE);
269 }
270 else if (USARTx == UART4)
271 {
272 periphclk = LL_RCC_GetUARTClockFreq(LL_RCC_UART4_CLKSOURCE);
273 }
274 else if (USARTx == UART5)
275 {
276 periphclk = LL_RCC_GetUARTClockFreq(LL_RCC_UART5_CLKSOURCE);
277 }
278 else
279 {
280 /* Nothing to do, as error code is already assigned to ERROR value */
281 }
282
283 /* Configure the USART Baud Rate :
284 - prescaler value is required
285 - valid baud rate value (different from 0) is required
286 - Peripheral clock as returned by RCC service, should be valid (different from 0).
287 */
288 if ((periphclk != LL_RCC_PERIPH_FREQUENCY_NO)
289 && (USART_InitStruct->BaudRate != 0U))
290 {
291 status = SUCCESS;
292 LL_USART_SetBaudRate(USARTx,
293 periphclk,
294 USART_InitStruct->PrescalerValue,
295 USART_InitStruct->OverSampling,
296 USART_InitStruct->BaudRate);
297
298 /* Check BRR is greater than or equal to 16d */
299 assert_param(IS_LL_USART_BRR_MIN(USARTx->BRR));
300 }
301
302 /*---------------------------- USART PRESC Configuration -----------------------
303 * Configure USARTx PRESC (Prescaler) with parameters:
304 * - PrescalerValue: USART_PRESC_PRESCALER bits according to USART_InitStruct->PrescalerValue value.
305 */
306 LL_USART_SetPrescaler(USARTx, USART_InitStruct->PrescalerValue);
307 }
308 /* Endif (=> USART not in Disabled state => return ERROR) */
309
310 return (status);
311 }
312
313 /**
314 * @brief Set each @ref LL_USART_InitTypeDef field to default value.
315 * @param USART_InitStruct pointer to a @ref LL_USART_InitTypeDef structure
316 * whose fields will be set to default values.
317 * @retval None
318 */
319
LL_USART_StructInit(LL_USART_InitTypeDef * USART_InitStruct)320 void LL_USART_StructInit(LL_USART_InitTypeDef *USART_InitStruct)
321 {
322 /* Set USART_InitStruct fields to default values */
323 USART_InitStruct->PrescalerValue = LL_USART_PRESCALER_DIV1;
324 USART_InitStruct->BaudRate = USART_DEFAULT_BAUDRATE;
325 USART_InitStruct->DataWidth = LL_USART_DATAWIDTH_8B;
326 USART_InitStruct->StopBits = LL_USART_STOPBITS_1;
327 USART_InitStruct->Parity = LL_USART_PARITY_NONE ;
328 USART_InitStruct->TransferDirection = LL_USART_DIRECTION_TX_RX;
329 USART_InitStruct->HardwareFlowControl = LL_USART_HWCONTROL_NONE;
330 USART_InitStruct->OverSampling = LL_USART_OVERSAMPLING_16;
331 }
332
333 /**
334 * @brief Initialize USART Clock related settings according to the
335 * specified parameters in the USART_ClockInitStruct.
336 * @note As some bits in USART configuration registers can only be written when
337 * the USART is disabled (USART_CR1_UE bit =0), USART Peripheral should be in disabled state prior calling
338 * this function. Otherwise, ERROR result will be returned.
339 * @param USARTx USART Instance
340 * @param USART_ClockInitStruct pointer to a @ref LL_USART_ClockInitTypeDef structure
341 * that contains the Clock configuration information for the specified USART peripheral.
342 * @retval An ErrorStatus enumeration value:
343 * - SUCCESS: USART registers related to Clock settings are initialized according
344 * to USART_ClockInitStruct content
345 * - ERROR: Problem occurred during USART Registers initialization
346 */
LL_USART_ClockInit(USART_TypeDef * USARTx,const LL_USART_ClockInitTypeDef * USART_ClockInitStruct)347 ErrorStatus LL_USART_ClockInit(USART_TypeDef *USARTx, const LL_USART_ClockInitTypeDef *USART_ClockInitStruct)
348 {
349 ErrorStatus status = SUCCESS;
350
351 /* Check USART Instance and Clock signal output parameters */
352 assert_param(IS_UART_INSTANCE(USARTx));
353 assert_param(IS_LL_USART_CLOCKOUTPUT(USART_ClockInitStruct->ClockOutput));
354
355 /* USART needs to be in disabled state, in order to be able to configure some bits in
356 CRx registers */
357 if (LL_USART_IsEnabled(USARTx) == 0U)
358 {
359 /* Ensure USART instance is USART capable */
360 assert_param(IS_USART_INSTANCE(USARTx));
361
362 /* Check clock related parameters */
363 assert_param(IS_LL_USART_CLOCKPOLARITY(USART_ClockInitStruct->ClockPolarity));
364 assert_param(IS_LL_USART_CLOCKPHASE(USART_ClockInitStruct->ClockPhase));
365 assert_param(IS_LL_USART_LASTBITCLKOUTPUT(USART_ClockInitStruct->LastBitClockPulse));
366
367 /*---------------------------- USART CR2 Configuration -----------------------
368 * Configure USARTx CR2 (Clock signal related bits) with parameters:
369 * - Clock Output: USART_CR2_CLKEN bit according to USART_ClockInitStruct->ClockOutput value
370 * - Clock Polarity: USART_CR2_CPOL bit according to USART_ClockInitStruct->ClockPolarity value
371 * - Clock Phase: USART_CR2_CPHA bit according to USART_ClockInitStruct->ClockPhase value
372 * - Last Bit Clock Pulse Output: USART_CR2_LBCL bit according to USART_ClockInitStruct->LastBitClockPulse value.
373 */
374 MODIFY_REG(USARTx->CR2,
375 USART_CR2_CLKEN | USART_CR2_CPHA | USART_CR2_CPOL | USART_CR2_LBCL,
376 USART_ClockInitStruct->ClockOutput | USART_ClockInitStruct->ClockPolarity |
377 USART_ClockInitStruct->ClockPhase | USART_ClockInitStruct->LastBitClockPulse);
378 }
379 /* Else (USART not in Disabled state => return ERROR */
380 else
381 {
382 status = ERROR;
383 }
384
385 return (status);
386 }
387
388 /**
389 * @brief Set each field of a @ref LL_USART_ClockInitTypeDef type structure to default value.
390 * @param USART_ClockInitStruct pointer to a @ref LL_USART_ClockInitTypeDef structure
391 * whose fields will be set to default values.
392 * @retval None
393 */
LL_USART_ClockStructInit(LL_USART_ClockInitTypeDef * USART_ClockInitStruct)394 void LL_USART_ClockStructInit(LL_USART_ClockInitTypeDef *USART_ClockInitStruct)
395 {
396 /* Set LL_USART_ClockInitStruct fields with default values */
397 USART_ClockInitStruct->ClockOutput = LL_USART_CLOCK_DISABLE;
398 USART_ClockInitStruct->ClockPolarity = LL_USART_POLARITY_LOW; /* Not relevant when ClockOutput =
399 LL_USART_CLOCK_DISABLE */
400 USART_ClockInitStruct->ClockPhase = LL_USART_PHASE_1EDGE; /* Not relevant when ClockOutput =
401 LL_USART_CLOCK_DISABLE */
402 USART_ClockInitStruct->LastBitClockPulse = LL_USART_LASTCLKPULSE_NO_OUTPUT; /* Not relevant when ClockOutput =
403 LL_USART_CLOCK_DISABLE */
404 }
405
406 /**
407 * @}
408 */
409
410 /**
411 * @}
412 */
413
414 /**
415 * @}
416 */
417
418 #endif /* USART1 || USART2 || USART3 || UART4 || UART5 */
419
420 /**
421 * @}
422 */
423
424 #endif /* USE_FULL_LL_DRIVER */
425
426
427
