1 /**
2 ******************************************************************************
3 * @file stm32wlxx_ll_usart.c
4 * @author MCD Application Team
5 * @brief USART LL module driver.
6 ******************************************************************************
7 * @attention
8 *
9 * Copyright (c) 2020 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 "stm32wlxx_ll_usart.h"
22 #include "stm32wlxx_ll_rcc.h"
23 #include "stm32wlxx_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 STM32WLxx_LL_Driver
31 * @{
32 */
33
34 #if defined (USART1) || defined (USART2)
35
36 /** @addtogroup USART_LL
37 * @{
38 */
39
40 /* Private types -------------------------------------------------------------*/
41 /* Private variables ---------------------------------------------------------*/
42 /* Private constants ---------------------------------------------------------*/
43 /* Private macros ------------------------------------------------------------*/
44 /** @addtogroup USART_LL_Private_Macros
45 * @{
46 */
47
48 #define IS_LL_USART_PRESCALER(__VALUE__) (((__VALUE__) == LL_USART_PRESCALER_DIV1) \
49 || ((__VALUE__) == LL_USART_PRESCALER_DIV2) \
50 || ((__VALUE__) == LL_USART_PRESCALER_DIV4) \
51 || ((__VALUE__) == LL_USART_PRESCALER_DIV6) \
52 || ((__VALUE__) == LL_USART_PRESCALER_DIV8) \
53 || ((__VALUE__) == LL_USART_PRESCALER_DIV10) \
54 || ((__VALUE__) == LL_USART_PRESCALER_DIV12) \
55 || ((__VALUE__) == LL_USART_PRESCALER_DIV16) \
56 || ((__VALUE__) == LL_USART_PRESCALER_DIV32) \
57 || ((__VALUE__) == LL_USART_PRESCALER_DIV64) \
58 || ((__VALUE__) == LL_USART_PRESCALER_DIV128) \
59 || ((__VALUE__) == LL_USART_PRESCALER_DIV256))
60
61 /* __BAUDRATE__ The maximum Baud Rate is derived from the maximum clock available
62 * divided by the smallest oversampling used on the USART (i.e. 8) */
63 #define IS_LL_USART_BAUDRATE(__BAUDRATE__) ((__BAUDRATE__) <= 6000001U)
64
65 /* __VALUE__ In case of oversampling by 16 and 8, BRR content must be greater than or equal to 16d. */
66 #define IS_LL_USART_BRR_MIN(__VALUE__) ((__VALUE__) >= 16U)
67
68 #define IS_LL_USART_DIRECTION(__VALUE__) (((__VALUE__) == LL_USART_DIRECTION_NONE) \
69 || ((__VALUE__) == LL_USART_DIRECTION_RX) \
70 || ((__VALUE__) == LL_USART_DIRECTION_TX) \
71 || ((__VALUE__) == LL_USART_DIRECTION_TX_RX))
72
73 #define IS_LL_USART_PARITY(__VALUE__) (((__VALUE__) == LL_USART_PARITY_NONE) \
74 || ((__VALUE__) == LL_USART_PARITY_EVEN) \
75 || ((__VALUE__) == LL_USART_PARITY_ODD))
76
77 #define IS_LL_USART_DATAWIDTH(__VALUE__) (((__VALUE__) == LL_USART_DATAWIDTH_7B) \
78 || ((__VALUE__) == LL_USART_DATAWIDTH_8B) \
79 || ((__VALUE__) == LL_USART_DATAWIDTH_9B))
80
81 #define IS_LL_USART_OVERSAMPLING(__VALUE__) (((__VALUE__) == LL_USART_OVERSAMPLING_16) \
82 || ((__VALUE__) == LL_USART_OVERSAMPLING_8))
83
84 #define IS_LL_USART_LASTBITCLKOUTPUT(__VALUE__) (((__VALUE__) == LL_USART_LASTCLKPULSE_NO_OUTPUT) \
85 || ((__VALUE__) == LL_USART_LASTCLKPULSE_OUTPUT))
86
87 #define IS_LL_USART_CLOCKPHASE(__VALUE__) (((__VALUE__) == LL_USART_PHASE_1EDGE) \
88 || ((__VALUE__) == LL_USART_PHASE_2EDGE))
89
90 #define IS_LL_USART_CLOCKPOLARITY(__VALUE__) (((__VALUE__) == LL_USART_POLARITY_LOW) \
91 || ((__VALUE__) == LL_USART_POLARITY_HIGH))
92
93 #define IS_LL_USART_CLOCKOUTPUT(__VALUE__) (((__VALUE__) == LL_USART_CLOCK_DISABLE) \
94 || ((__VALUE__) == LL_USART_CLOCK_ENABLE))
95
96 #define IS_LL_USART_STOPBITS(__VALUE__) (((__VALUE__) == LL_USART_STOPBITS_0_5) \
97 || ((__VALUE__) == LL_USART_STOPBITS_1) \
98 || ((__VALUE__) == LL_USART_STOPBITS_1_5) \
99 || ((__VALUE__) == LL_USART_STOPBITS_2))
100
101 #define IS_LL_USART_HWCONTROL(__VALUE__) (((__VALUE__) == LL_USART_HWCONTROL_NONE) \
102 || ((__VALUE__) == LL_USART_HWCONTROL_RTS) \
103 || ((__VALUE__) == LL_USART_HWCONTROL_CTS) \
104 || ((__VALUE__) == LL_USART_HWCONTROL_RTS_CTS))
105
106 /**
107 * @}
108 */
109
110 /* Private function prototypes -----------------------------------------------*/
111
112 /* Exported functions --------------------------------------------------------*/
113 /** @addtogroup USART_LL_Exported_Functions
114 * @{
115 */
116
117 /** @addtogroup USART_LL_EF_Init
118 * @{
119 */
120
121 /**
122 * @brief De-initialize USART registers (Registers restored to their default values).
123 * @param USARTx USART Instance
124 * @retval An ErrorStatus enumeration value:
125 * - SUCCESS: USART registers are de-initialized
126 * - ERROR: USART registers are not de-initialized
127 */
LL_USART_DeInit(const USART_TypeDef * USARTx)128 ErrorStatus LL_USART_DeInit(const USART_TypeDef *USARTx)
129 {
130 ErrorStatus status = SUCCESS;
131
132 /* Check the parameters */
133 assert_param(IS_UART_INSTANCE(USARTx));
134
135 if (USARTx == USART1)
136 {
137 /* Force reset of USART clock */
138 LL_APB2_GRP1_ForceReset(LL_APB2_GRP1_PERIPH_USART1);
139
140 /* Release reset of USART clock */
141 LL_APB2_GRP1_ReleaseReset(LL_APB2_GRP1_PERIPH_USART1);
142 }
143 else if (USARTx == USART2)
144 {
145 /* Force reset of USART clock */
146 LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART2);
147
148 /* Release reset of USART clock */
149 LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART2);
150 }
151 else
152 {
153 status = ERROR;
154 }
155
156 return (status);
157 }
158
159 /**
160 * @brief Initialize USART registers according to the specified
161 * parameters in USART_InitStruct.
162 * @note As some bits in USART configuration registers can only be written when the USART is disabled (USART_CR1_UE bit =0),
163 * USART Peripheral should be in disabled state prior calling this function. Otherwise, ERROR result will be returned.
164 * @note Baud rate value stored in USART_InitStruct BaudRate field, should be valid (different from 0).
165 * @param USARTx USART Instance
166 * @param USART_InitStruct pointer to a LL_USART_InitTypeDef structure
167 * that contains the configuration information for the specified USART peripheral.
168 * @retval An ErrorStatus enumeration value:
169 * - SUCCESS: USART registers are initialized according to USART_InitStruct content
170 * - ERROR: Problem occurred during USART Registers initialization
171 */
LL_USART_Init(USART_TypeDef * USARTx,const LL_USART_InitTypeDef * USART_InitStruct)172 ErrorStatus LL_USART_Init(USART_TypeDef *USARTx, const LL_USART_InitTypeDef *USART_InitStruct)
173 {
174 ErrorStatus status = ERROR;
175 uint32_t periphclk = LL_RCC_PERIPH_FREQUENCY_NO;
176
177 /* Check the parameters */
178 assert_param(IS_UART_INSTANCE(USARTx));
179 assert_param(IS_LL_USART_PRESCALER(USART_InitStruct->PrescalerValue));
180 assert_param(IS_LL_USART_BAUDRATE(USART_InitStruct->BaudRate));
181 assert_param(IS_LL_USART_DATAWIDTH(USART_InitStruct->DataWidth));
182 assert_param(IS_LL_USART_STOPBITS(USART_InitStruct->StopBits));
183 assert_param(IS_LL_USART_PARITY(USART_InitStruct->Parity));
184 assert_param(IS_LL_USART_DIRECTION(USART_InitStruct->TransferDirection));
185 assert_param(IS_LL_USART_HWCONTROL(USART_InitStruct->HardwareFlowControl));
186 assert_param(IS_LL_USART_OVERSAMPLING(USART_InitStruct->OverSampling));
187
188 /* USART needs to be in disabled state, in order to be able to configure some bits in
189 CRx registers */
190 if (LL_USART_IsEnabled(USARTx) == 0U)
191 {
192 /*---------------------------- USART CR1 Configuration ---------------------
193 * Configure USARTx CR1 (USART Word Length, Parity, Mode and Oversampling bits) with parameters:
194 * - DataWidth: USART_CR1_M bits according to USART_InitStruct->DataWidth value
195 * - Parity: USART_CR1_PCE, USART_CR1_PS bits according to USART_InitStruct->Parity value
196 * - TransferDirection: USART_CR1_TE, USART_CR1_RE bits according to USART_InitStruct->TransferDirection value
197 * - Oversampling: USART_CR1_OVER8 bit according to USART_InitStruct->OverSampling value.
198 */
199 MODIFY_REG(USARTx->CR1,
200 (USART_CR1_M | USART_CR1_PCE | USART_CR1_PS |
201 USART_CR1_TE | USART_CR1_RE | USART_CR1_OVER8),
202 (USART_InitStruct->DataWidth | USART_InitStruct->Parity |
203 USART_InitStruct->TransferDirection | USART_InitStruct->OverSampling));
204
205 /*---------------------------- USART CR2 Configuration ---------------------
206 * Configure USARTx CR2 (Stop bits) with parameters:
207 * - Stop Bits: USART_CR2_STOP bits according to USART_InitStruct->StopBits value.
208 * - CLKEN, CPOL, CPHA and LBCL bits are to be configured using LL_USART_ClockInit().
209 */
210 LL_USART_SetStopBitsLength(USARTx, USART_InitStruct->StopBits);
211
212 /*---------------------------- USART CR3 Configuration ---------------------
213 * Configure USARTx CR3 (Hardware Flow Control) with parameters:
214 * - HardwareFlowControl: USART_CR3_RTSE, USART_CR3_CTSE bits according to USART_InitStruct->HardwareFlowControl value.
215 */
216 LL_USART_SetHWFlowCtrl(USARTx, USART_InitStruct->HardwareFlowControl);
217
218 /*---------------------------- USART BRR Configuration ---------------------
219 * Retrieve Clock frequency used for USART Peripheral
220 */
221 if (USARTx == USART1)
222 {
223 periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART1_CLKSOURCE);
224 }
225 else if (USARTx == USART2)
226 {
227 periphclk = LL_RCC_GetUSARTClockFreq(LL_RCC_USART2_CLKSOURCE);
228 }
229 else
230 {
231 /* Nothing to do, as error code is already assigned to ERROR value */
232 }
233
234 /* Configure the USART Baud Rate :
235 - prescaler value is required
236 - valid baud rate value (different from 0) is required
237 - Peripheral clock as returned by RCC service, should be valid (different from 0).
238 */
239 if ((periphclk != LL_RCC_PERIPH_FREQUENCY_NO)
240 && (USART_InitStruct->BaudRate != 0U))
241 {
242 status = SUCCESS;
243 LL_USART_SetBaudRate(USARTx,
244 periphclk,
245 USART_InitStruct->PrescalerValue,
246 USART_InitStruct->OverSampling,
247 USART_InitStruct->BaudRate);
248
249 /* Check BRR is greater than or equal to 16d */
250 assert_param(IS_LL_USART_BRR_MIN(USARTx->BRR));
251 }
252
253 /*---------------------------- USART PRESC Configuration -----------------------
254 * Configure USARTx PRESC (Prescaler) with parameters:
255 * - PrescalerValue: USART_PRESC_PRESCALER bits according to USART_InitStruct->PrescalerValue value.
256 */
257 LL_USART_SetPrescaler(USARTx, USART_InitStruct->PrescalerValue);
258 }
259 /* Endif (=> USART not in Disabled state => return ERROR) */
260
261 return (status);
262 }
263
264 /**
265 * @brief Set each @ref LL_USART_InitTypeDef field to default value.
266 * @param USART_InitStruct pointer to a @ref LL_USART_InitTypeDef structure
267 * whose fields will be set to default values.
268 * @retval None
269 */
270
LL_USART_StructInit(LL_USART_InitTypeDef * USART_InitStruct)271 void LL_USART_StructInit(LL_USART_InitTypeDef *USART_InitStruct)
272 {
273 /* Set USART_InitStruct fields to default values */
274 USART_InitStruct->PrescalerValue = LL_USART_PRESCALER_DIV1;
275 USART_InitStruct->BaudRate = 9600U;
276 USART_InitStruct->DataWidth = LL_USART_DATAWIDTH_8B;
277 USART_InitStruct->StopBits = LL_USART_STOPBITS_1;
278 USART_InitStruct->Parity = LL_USART_PARITY_NONE ;
279 USART_InitStruct->TransferDirection = LL_USART_DIRECTION_TX_RX;
280 USART_InitStruct->HardwareFlowControl = LL_USART_HWCONTROL_NONE;
281 USART_InitStruct->OverSampling = LL_USART_OVERSAMPLING_16;
282 }
283
284 /**
285 * @brief Initialize USART Clock related settings according to the
286 * specified parameters in the USART_ClockInitStruct.
287 * @note As some bits in USART configuration registers can only be written when the USART is disabled (USART_CR1_UE bit =0),
288 * USART Peripheral should be in disabled state prior calling this function. Otherwise, ERROR result will be returned.
289 * @param USARTx USART Instance
290 * @param USART_ClockInitStruct pointer to a @ref LL_USART_ClockInitTypeDef structure
291 * that contains the Clock configuration information for the specified USART peripheral.
292 * @retval An ErrorStatus enumeration value:
293 * - SUCCESS: USART registers related to Clock settings are initialized according to USART_ClockInitStruct content
294 * - ERROR: Problem occurred during USART Registers initialization
295 */
LL_USART_ClockInit(USART_TypeDef * USARTx,const LL_USART_ClockInitTypeDef * USART_ClockInitStruct)296 ErrorStatus LL_USART_ClockInit(USART_TypeDef *USARTx, const LL_USART_ClockInitTypeDef *USART_ClockInitStruct)
297 {
298 ErrorStatus status = SUCCESS;
299
300 /* Check USART Instance and Clock signal output parameters */
301 assert_param(IS_UART_INSTANCE(USARTx));
302 assert_param(IS_LL_USART_CLOCKOUTPUT(USART_ClockInitStruct->ClockOutput));
303
304 /* USART needs to be in disabled state, in order to be able to configure some bits in
305 CRx registers */
306 if (LL_USART_IsEnabled(USARTx) == 0U)
307 {
308 /* Ensure USART instance is USART capable */
309 assert_param(IS_USART_INSTANCE(USARTx));
310
311 /* Check clock related parameters */
312 assert_param(IS_LL_USART_CLOCKPOLARITY(USART_ClockInitStruct->ClockPolarity));
313 assert_param(IS_LL_USART_CLOCKPHASE(USART_ClockInitStruct->ClockPhase));
314 assert_param(IS_LL_USART_LASTBITCLKOUTPUT(USART_ClockInitStruct->LastBitClockPulse));
315
316 /*---------------------------- USART CR2 Configuration -----------------------
317 * Configure USARTx CR2 (Clock signal related bits) with parameters:
318 * - Clock Output: USART_CR2_CLKEN bit according to USART_ClockInitStruct->ClockOutput value
319 * - Clock Polarity: USART_CR2_CPOL bit according to USART_ClockInitStruct->ClockPolarity value
320 * - Clock Phase: USART_CR2_CPHA bit according to USART_ClockInitStruct->ClockPhase value
321 * - Last Bit Clock Pulse Output: USART_CR2_LBCL bit according to USART_ClockInitStruct->LastBitClockPulse value.
322 */
323 MODIFY_REG(USARTx->CR2,
324 USART_CR2_CLKEN | USART_CR2_CPHA | USART_CR2_CPOL | USART_CR2_LBCL,
325 USART_ClockInitStruct->ClockOutput | USART_ClockInitStruct->ClockPolarity |
326 USART_ClockInitStruct->ClockPhase | USART_ClockInitStruct->LastBitClockPulse);
327 }
328 /* Else (USART not in Disabled state => return ERROR */
329 else
330 {
331 status = ERROR;
332 }
333
334 return (status);
335 }
336
337 /**
338 * @brief Set each field of a @ref LL_USART_ClockInitTypeDef type structure to default value.
339 * @param USART_ClockInitStruct pointer to a @ref LL_USART_ClockInitTypeDef structure
340 * whose fields will be set to default values.
341 * @retval None
342 */
LL_USART_ClockStructInit(LL_USART_ClockInitTypeDef * USART_ClockInitStruct)343 void LL_USART_ClockStructInit(LL_USART_ClockInitTypeDef *USART_ClockInitStruct)
344 {
345 /* Set LL_USART_ClockInitStruct fields with default values */
346 USART_ClockInitStruct->ClockOutput = LL_USART_CLOCK_DISABLE;
347 USART_ClockInitStruct->ClockPolarity = LL_USART_POLARITY_LOW; /* Not relevant when ClockOutput = LL_USART_CLOCK_DISABLE */
348 USART_ClockInitStruct->ClockPhase = LL_USART_PHASE_1EDGE; /* Not relevant when ClockOutput = LL_USART_CLOCK_DISABLE */
349 USART_ClockInitStruct->LastBitClockPulse = LL_USART_LASTCLKPULSE_NO_OUTPUT; /* Not relevant when ClockOutput = LL_USART_CLOCK_DISABLE */
350 }
351
352 /**
353 * @}
354 */
355
356 /**
357 * @}
358 */
359
360 /**
361 * @}
362 */
363
364 #endif /* USART1 || USART2 */
365
366 /**
367 * @}
368 */
369
370 #endif /* USE_FULL_LL_DRIVER */
371
372
