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77 mjames 1
/**
2
  ******************************************************************************
3
  * @file    stm32l1xx_ll_usart.c
4
  * @author  MCD Application Team
5
  * @brief   USART LL module driver.
6
  ******************************************************************************
7
  * @attention
8
  *
9
  * Copyright (c) 2016 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
 
19
#if defined(USE_FULL_LL_DRIVER)
20
 
21
/* Includes ------------------------------------------------------------------*/
22
#include "stm32l1xx_ll_usart.h"
23
#include "stm32l1xx_ll_rcc.h"
24
#include "stm32l1xx_ll_bus.h"
25
#ifdef  USE_FULL_ASSERT
26
#include "stm32_assert.h"
27
#else
28
#define assert_param(expr) ((void)0U)
29
#endif
30
 
31
/** @addtogroup STM32L1xx_LL_Driver
32
  * @{
33
  */
34
 
35
#if defined (USART1) || defined (USART2) || defined (USART3) || defined (UART4) || defined (UART5)
36
 
37
/** @addtogroup USART_LL
38
  * @{
39
  */
40
 
41
/* Private types -------------------------------------------------------------*/
42
/* Private variables ---------------------------------------------------------*/
43
/* Private constants ---------------------------------------------------------*/
44
/** @addtogroup USART_LL_Private_Constants
45
  * @{
46
  */
47
 
48
/**
49
  * @}
50
  */
51
 
52
 
53
/* Private macros ------------------------------------------------------------*/
54
/** @addtogroup USART_LL_Private_Macros
55
  * @{
56
  */
57
 
58
/* __BAUDRATE__ The maximum Baud Rate is derived from the maximum clock available
59
 *              divided by the smallest oversampling used on the USART (i.e. 8)    */
60
#define IS_LL_USART_BAUDRATE(__BAUDRATE__) ((__BAUDRATE__) <= 4000000U)
61
 
62
/* __VALUE__ In case of oversampling by 16 and 8, BRR content must be greater than or equal to 16d. */
63
#define IS_LL_USART_BRR_MIN(__VALUE__) ((__VALUE__) >= 16U)
64
 
65
#define IS_LL_USART_DIRECTION(__VALUE__) (((__VALUE__) == LL_USART_DIRECTION_NONE) \
66
                                          || ((__VALUE__) == LL_USART_DIRECTION_RX) \
67
                                          || ((__VALUE__) == LL_USART_DIRECTION_TX) \
68
                                          || ((__VALUE__) == LL_USART_DIRECTION_TX_RX))
69
 
70
#define IS_LL_USART_PARITY(__VALUE__) (((__VALUE__) == LL_USART_PARITY_NONE) \
71
                                       || ((__VALUE__) == LL_USART_PARITY_EVEN) \
72
                                       || ((__VALUE__) == LL_USART_PARITY_ODD))
73
 
74
#define IS_LL_USART_DATAWIDTH(__VALUE__) (((__VALUE__) == LL_USART_DATAWIDTH_8B) \
75
                                          || ((__VALUE__) == LL_USART_DATAWIDTH_9B))
76
 
77
#define IS_LL_USART_OVERSAMPLING(__VALUE__) (((__VALUE__) == LL_USART_OVERSAMPLING_16) \
78
                                             || ((__VALUE__) == LL_USART_OVERSAMPLING_8))
79
 
80
#define IS_LL_USART_LASTBITCLKOUTPUT(__VALUE__) (((__VALUE__) == LL_USART_LASTCLKPULSE_NO_OUTPUT) \
81
                                                 || ((__VALUE__) == LL_USART_LASTCLKPULSE_OUTPUT))
82
 
83
#define IS_LL_USART_CLOCKPHASE(__VALUE__) (((__VALUE__) == LL_USART_PHASE_1EDGE) \
84
                                           || ((__VALUE__) == LL_USART_PHASE_2EDGE))
85
 
86
#define IS_LL_USART_CLOCKPOLARITY(__VALUE__) (((__VALUE__) == LL_USART_POLARITY_LOW) \
87
                                              || ((__VALUE__) == LL_USART_POLARITY_HIGH))
88
 
89
#define IS_LL_USART_CLOCKOUTPUT(__VALUE__) (((__VALUE__) == LL_USART_CLOCK_DISABLE) \
90
                                            || ((__VALUE__) == LL_USART_CLOCK_ENABLE))
91
 
92
#define IS_LL_USART_STOPBITS(__VALUE__) (((__VALUE__) == LL_USART_STOPBITS_0_5) \
93
                                         || ((__VALUE__) == LL_USART_STOPBITS_1) \
94
                                         || ((__VALUE__) == LL_USART_STOPBITS_1_5) \
95
                                         || ((__VALUE__) == LL_USART_STOPBITS_2))
96
 
97
#define IS_LL_USART_HWCONTROL(__VALUE__) (((__VALUE__) == LL_USART_HWCONTROL_NONE) \
98
                                          || ((__VALUE__) == LL_USART_HWCONTROL_RTS) \
99
                                          || ((__VALUE__) == LL_USART_HWCONTROL_CTS) \
100
                                          || ((__VALUE__) == LL_USART_HWCONTROL_RTS_CTS))
101
 
102
/**
103
  * @}
104
  */
105
 
106
/* Private function prototypes -----------------------------------------------*/
107
 
108
/* Exported functions --------------------------------------------------------*/
109
/** @addtogroup USART_LL_Exported_Functions
110
  * @{
111
  */
112
 
113
/** @addtogroup USART_LL_EF_Init
114
  * @{
115
  */
116
 
117
/**
118
  * @brief  De-initialize USART registers (Registers restored to their default values).
119
  * @param  USARTx USART Instance
120
  * @retval An ErrorStatus enumeration value:
121
  *          - SUCCESS: USART registers are de-initialized
122
  *          - ERROR: USART registers are not de-initialized
123
  */
124
ErrorStatus LL_USART_DeInit(const USART_TypeDef *USARTx)
125
{
126
  ErrorStatus status = SUCCESS;
127
 
128
  /* Check the parameters */
129
  assert_param(IS_UART_INSTANCE(USARTx));
130
 
131
  if (USARTx == USART1)
132
  {
133
    /* Force reset of USART clock */
134
    LL_APB2_GRP1_ForceReset(LL_APB2_GRP1_PERIPH_USART1);
135
 
136
    /* Release reset of USART clock */
137
    LL_APB2_GRP1_ReleaseReset(LL_APB2_GRP1_PERIPH_USART1);
138
  }
139
  else if (USARTx == USART2)
140
  {
141
    /* Force reset of USART clock */
142
    LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART2);
143
 
144
    /* Release reset of USART clock */
145
    LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART2);
146
  }
147
  else if (USARTx == USART3)
148
  {
149
    /* Force reset of USART clock */
150
    LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_USART3);
151
 
152
    /* Release reset of USART clock */
153
    LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_USART3);
154
  }
155
#if defined(UART4)
156
  else if (USARTx == UART4)
157
  {
158
    /* Force reset of UART clock */
159
    LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_UART4);
160
 
161
    /* Release reset of UART clock */
162
    LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_UART4);
163
  }
164
#endif /* UART4 */
165
#if defined(UART5)
166
  else if (USARTx == UART5)
167
  {
168
    /* Force reset of UART clock */
169
    LL_APB1_GRP1_ForceReset(LL_APB1_GRP1_PERIPH_UART5);
170
 
171
    /* Release reset of UART clock */
172
    LL_APB1_GRP1_ReleaseReset(LL_APB1_GRP1_PERIPH_UART5);
173
  }
174
#endif /* UART5 */
175
  else
176
  {
177
    status = ERROR;
178
  }
179
 
180
  return (status);
181
}
182
 
183
/**
184
  * @brief  Initialize USART registers according to the specified
185
  *         parameters in USART_InitStruct.
186
  * @note   As some bits in USART configuration registers can only be written when the USART is disabled (USART_CR1_UE bit =0),
187
  *         USART IP should be in disabled state prior calling this function. Otherwise, ERROR result will be returned.
188
  * @note   Baud rate value stored in USART_InitStruct BaudRate field, should be valid (different from 0).
189
  * @param  USARTx USART Instance
190
  * @param  USART_InitStruct pointer to a LL_USART_InitTypeDef structure
191
  *         that contains the configuration information for the specified USART peripheral.
192
  * @retval An ErrorStatus enumeration value:
193
  *          - SUCCESS: USART registers are initialized according to USART_InitStruct content
194
  *          - ERROR: Problem occurred during USART Registers initialization
195
  */
196
ErrorStatus LL_USART_Init(USART_TypeDef *USARTx, const LL_USART_InitTypeDef *USART_InitStruct)
197
{
198
  ErrorStatus status = ERROR;
199
  uint32_t periphclk = LL_RCC_PERIPH_FREQUENCY_NO;
200
  LL_RCC_ClocksTypeDef rcc_clocks;
201
 
202
  /* Check the parameters */
203
  assert_param(IS_UART_INSTANCE(USARTx));
204
  assert_param(IS_LL_USART_BAUDRATE(USART_InitStruct->BaudRate));
205
  assert_param(IS_LL_USART_DATAWIDTH(USART_InitStruct->DataWidth));
206
  assert_param(IS_LL_USART_STOPBITS(USART_InitStruct->StopBits));
207
  assert_param(IS_LL_USART_PARITY(USART_InitStruct->Parity));
208
  assert_param(IS_LL_USART_DIRECTION(USART_InitStruct->TransferDirection));
209
  assert_param(IS_LL_USART_HWCONTROL(USART_InitStruct->HardwareFlowControl));
210
  assert_param(IS_LL_USART_OVERSAMPLING(USART_InitStruct->OverSampling));
211
 
212
  /* USART needs to be in disabled state, in order to be able to configure some bits in
213
     CRx registers */
214
  if (LL_USART_IsEnabled(USARTx) == 0U)
215
  {
216
    /*---------------------------- USART CR1 Configuration -----------------------
217
     * Configure USARTx CR1 (USART Word Length, Parity, Mode and Oversampling bits) with parameters:
218
     * - DataWidth:          USART_CR1_M bits according to USART_InitStruct->DataWidth value
219
     * - Parity:             USART_CR1_PCE, USART_CR1_PS bits according to USART_InitStruct->Parity value
220
     * - TransferDirection:  USART_CR1_TE, USART_CR1_RE bits according to USART_InitStruct->TransferDirection value
221
     * - Oversampling:       USART_CR1_OVER8 bit according to USART_InitStruct->OverSampling value.
222
     */
223
    MODIFY_REG(USARTx->CR1,
224
               (USART_CR1_M | USART_CR1_PCE | USART_CR1_PS |
225
                USART_CR1_TE | USART_CR1_RE | USART_CR1_OVER8),
226
               (USART_InitStruct->DataWidth | USART_InitStruct->Parity |
227
                USART_InitStruct->TransferDirection | USART_InitStruct->OverSampling));
228
 
229
    /*---------------------------- USART CR2 Configuration -----------------------
230
     * Configure USARTx CR2 (Stop bits) with parameters:
231
     * - Stop Bits:          USART_CR2_STOP bits according to USART_InitStruct->StopBits value.
232
     * - CLKEN, CPOL, CPHA and LBCL bits are to be configured using LL_USART_ClockInit().
233
     */
234
    LL_USART_SetStopBitsLength(USARTx, USART_InitStruct->StopBits);
235
 
236
    /*---------------------------- USART CR3 Configuration -----------------------
237
     * Configure USARTx CR3 (Hardware Flow Control) with parameters:
238
     * - HardwareFlowControl: USART_CR3_RTSE, USART_CR3_CTSE bits according to USART_InitStruct->HardwareFlowControl value.
239
     */
240
    LL_USART_SetHWFlowCtrl(USARTx, USART_InitStruct->HardwareFlowControl);
241
 
242
    /*---------------------------- USART BRR Configuration -----------------------
243
     * Retrieve Clock frequency used for USART Peripheral
244
     */
245
    LL_RCC_GetSystemClocksFreq(&rcc_clocks);
246
    if (USARTx == USART1)
247
    {
248
      periphclk = rcc_clocks.PCLK2_Frequency;
249
    }
250
    else if (USARTx == USART2)
251
    {
252
      periphclk = rcc_clocks.PCLK1_Frequency;
253
    }
254
    else if (USARTx == USART3)
255
    {
256
      periphclk = rcc_clocks.PCLK1_Frequency;
257
    }
258
#if defined(UART4)
259
    else if (USARTx == UART4)
260
    {
261
      periphclk = rcc_clocks.PCLK1_Frequency;
262
    }
263
#endif /* UART4 */
264
#if defined(UART5)
265
    else if (USARTx == UART5)
266
    {
267
      periphclk = rcc_clocks.PCLK1_Frequency;
268
    }
269
#endif /* UART5 */
270
    else
271
    {
272
      /* Nothing to do, as error code is already assigned to ERROR value */
273
    }
274
 
275
    /* Configure the USART Baud Rate :
276
       - valid baud rate value (different from 0) is required
277
       - Peripheral clock as returned by RCC service, should be valid (different from 0).
278
    */
279
    if ((periphclk != LL_RCC_PERIPH_FREQUENCY_NO)
280
        && (USART_InitStruct->BaudRate != 0U))
281
    {
282
      status = SUCCESS;
283
      LL_USART_SetBaudRate(USARTx,
284
                           periphclk,
285
                           USART_InitStruct->OverSampling,
286
                           USART_InitStruct->BaudRate);
287
 
288
      /* Check BRR is greater than or equal to 16d */
289
      assert_param(IS_LL_USART_BRR_MIN(USARTx->BRR));
290
    }
291
  }
292
  /* Endif (=> USART not in Disabled state => return ERROR) */
293
 
294
  return (status);
295
}
296
 
297
/**
298
  * @brief Set each @ref LL_USART_InitTypeDef field to default value.
299
  * @param USART_InitStruct Pointer to a @ref LL_USART_InitTypeDef structure
300
  *                         whose fields will be set to default values.
301
  * @retval None
302
  */
303
 
304
void LL_USART_StructInit(LL_USART_InitTypeDef *USART_InitStruct)
305
{
306
  /* Set USART_InitStruct fields to default values */
307
  USART_InitStruct->BaudRate            = 9600U;
308
  USART_InitStruct->DataWidth           = LL_USART_DATAWIDTH_8B;
309
  USART_InitStruct->StopBits            = LL_USART_STOPBITS_1;
310
  USART_InitStruct->Parity              = LL_USART_PARITY_NONE ;
311
  USART_InitStruct->TransferDirection   = LL_USART_DIRECTION_TX_RX;
312
  USART_InitStruct->HardwareFlowControl = LL_USART_HWCONTROL_NONE;
313
  USART_InitStruct->OverSampling        = LL_USART_OVERSAMPLING_16;
314
}
315
 
316
/**
317
  * @brief  Initialize USART Clock related settings according to the
318
  *         specified parameters in the USART_ClockInitStruct.
319
  * @note   As some bits in USART configuration registers can only be written when the USART is disabled (USART_CR1_UE bit =0),
320
  *         USART IP should be in disabled state prior calling this function. Otherwise, ERROR result will be returned.
321
  * @param  USARTx USART Instance
322
  * @param  USART_ClockInitStruct Pointer to a @ref LL_USART_ClockInitTypeDef structure
323
  *         that contains the Clock configuration information for the specified USART peripheral.
324
  * @retval An ErrorStatus enumeration value:
325
  *          - SUCCESS: USART registers related to Clock settings are initialized according to USART_ClockInitStruct content
326
  *          - ERROR: Problem occurred during USART Registers initialization
327
  */
328
ErrorStatus LL_USART_ClockInit(USART_TypeDef *USARTx, const LL_USART_ClockInitTypeDef *USART_ClockInitStruct)
329
{
330
  ErrorStatus status = SUCCESS;
331
 
332
  /* Check USART Instance and Clock signal output parameters */
333
  assert_param(IS_UART_INSTANCE(USARTx));
334
  assert_param(IS_LL_USART_CLOCKOUTPUT(USART_ClockInitStruct->ClockOutput));
335
 
336
  /* USART needs to be in disabled state, in order to be able to configure some bits in
337
     CRx registers */
338
  if (LL_USART_IsEnabled(USARTx) == 0U)
339
  {
340
    /*---------------------------- USART CR2 Configuration -----------------------*/
341
    /* If Clock signal has to be output */
342
    if (USART_ClockInitStruct->ClockOutput == LL_USART_CLOCK_DISABLE)
343
    {
344
      /* Deactivate Clock signal delivery :
345
       * - Disable Clock Output:        USART_CR2_CLKEN cleared
346
       */
347
      LL_USART_DisableSCLKOutput(USARTx);
348
    }
349
    else
350
    {
351
      /* Ensure USART instance is USART capable */
352
      assert_param(IS_USART_INSTANCE(USARTx));
353
 
354
      /* Check clock related parameters */
355
      assert_param(IS_LL_USART_CLOCKPOLARITY(USART_ClockInitStruct->ClockPolarity));
356
      assert_param(IS_LL_USART_CLOCKPHASE(USART_ClockInitStruct->ClockPhase));
357
      assert_param(IS_LL_USART_LASTBITCLKOUTPUT(USART_ClockInitStruct->LastBitClockPulse));
358
 
359
      /*---------------------------- USART CR2 Configuration -----------------------
360
       * Configure USARTx CR2 (Clock signal related bits) with parameters:
361
       * - Enable Clock Output:         USART_CR2_CLKEN set
362
       * - Clock Polarity:              USART_CR2_CPOL bit according to USART_ClockInitStruct->ClockPolarity value
363
       * - Clock Phase:                 USART_CR2_CPHA bit according to USART_ClockInitStruct->ClockPhase value
364
       * - Last Bit Clock Pulse Output: USART_CR2_LBCL bit according to USART_ClockInitStruct->LastBitClockPulse value.
365
       */
366
      MODIFY_REG(USARTx->CR2,
367
                 USART_CR2_CLKEN | USART_CR2_CPHA | USART_CR2_CPOL | USART_CR2_LBCL,
368
                 USART_CR2_CLKEN | USART_ClockInitStruct->ClockPolarity |
369
                 USART_ClockInitStruct->ClockPhase | USART_ClockInitStruct->LastBitClockPulse);
370
    }
371
  }
372
  /* Else (USART not in Disabled state => return ERROR */
373
  else
374
  {
375
    status = ERROR;
376
  }
377
 
378
  return (status);
379
}
380
 
381
/**
382
  * @brief Set each field of a @ref LL_USART_ClockInitTypeDef type structure to default value.
383
  * @param USART_ClockInitStruct Pointer to a @ref LL_USART_ClockInitTypeDef structure
384
  *                              whose fields will be set to default values.
385
  * @retval None
386
  */
387
void LL_USART_ClockStructInit(LL_USART_ClockInitTypeDef *USART_ClockInitStruct)
388
{
389
  /* Set LL_USART_ClockInitStruct fields with default values */
390
  USART_ClockInitStruct->ClockOutput       = LL_USART_CLOCK_DISABLE;
391
  USART_ClockInitStruct->ClockPolarity     = LL_USART_POLARITY_LOW;            /* Not relevant when ClockOutput = LL_USART_CLOCK_DISABLE */
392
  USART_ClockInitStruct->ClockPhase        = LL_USART_PHASE_1EDGE;             /* Not relevant when ClockOutput = LL_USART_CLOCK_DISABLE */
393
  USART_ClockInitStruct->LastBitClockPulse = LL_USART_LASTCLKPULSE_NO_OUTPUT;  /* Not relevant when ClockOutput = LL_USART_CLOCK_DISABLE */
394
}
395
 
396
/**
397
  * @}
398
  */
399
 
400
/**
401
  * @}
402
  */
403
 
404
/**
405
  * @}
406
  */
407
 
408
#endif /* USART1 || USART2|| USART3 || UART4 || UART5 */
409
 
410
/**
411
  * @}
412
  */
413
 
414
#endif /* USE_FULL_LL_DRIVER */
415
 
416