1 /**
2   ******************************************************************************
3   * @file    stm32u5xx_ll_lpuart.c
4   * @author  MCD Application Team
5   * @brief   LPUART LL module driver.
6   ******************************************************************************
7   * @attention
8   *
9   * Copyright (c) 2021 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 "stm32u5xx_ll_lpuart.h"
22 #include "stm32u5xx_ll_rcc.h"
23 #include "stm32u5xx_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 STM32U5xx_LL_Driver
31   * @{
32   */
33 
34 #if defined (LPUART1)
35 
36 /** @addtogroup LPUART_LL
37   * @{
38   */
39 
40 /* Private types -------------------------------------------------------------*/
41 /* Private variables ---------------------------------------------------------*/
42 /* Private constants ---------------------------------------------------------*/
43 /** @addtogroup LPUART_LL_Private_Constants
44   * @{
45   */
46 
47 /* Definition of default baudrate value used for LPUART initialisation */
48 #define LPUART_DEFAULT_BAUDRATE          (9600U)
49 
50 /**
51   * @}
52   */
53 
54 
55 /* Private macros ------------------------------------------------------------*/
56 /** @addtogroup LPUART_LL_Private_Macros
57   * @{
58   */
59 
60 /* Check of parameters for configuration of LPUART registers                  */
61 
62 #define IS_LL_LPUART_PRESCALER(__VALUE__)  (((__VALUE__) == LL_LPUART_PRESCALER_DIV1) \
63                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV2) \
64                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV4) \
65                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV6) \
66                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV8) \
67                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV10) \
68                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV12) \
69                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV16) \
70                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV32) \
71                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV64) \
72                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV128) \
73                                             || ((__VALUE__) == LL_LPUART_PRESCALER_DIV256))
74 
75 /* __BAUDRATE__ Depending on constraints applicable for LPUART BRR register   */
76 /*              value :                                                       */
77 /*                - fck must be in the range [3 x baudrate, 4096 x baudrate]  */
78 /*                - LPUART_BRR register value should be >= 0x300              */
79 /*                - LPUART_BRR register value should be <= 0xFFFFF (20 bits)  */
80 /*              Baudrate specified by the user should belong to [8, 33000000].*/
81 #define IS_LL_LPUART_BAUDRATE(__BAUDRATE__) (((__BAUDRATE__) <= 33000000U) && ((__BAUDRATE__) >= 8U))
82 
83 /* __VALUE__ BRR content must be greater than or equal to 0x300. */
84 #define IS_LL_LPUART_BRR_MIN(__VALUE__)   ((__VALUE__) >= 0x300U)
85 
86 /* __VALUE__ BRR content must be lower than or equal to 0xFFFFF. */
87 #define IS_LL_LPUART_BRR_MAX(__VALUE__)   ((__VALUE__) <= 0x000FFFFFU)
88 
89 #define IS_LL_LPUART_DIRECTION(__VALUE__) (((__VALUE__) == LL_LPUART_DIRECTION_NONE) \
90                                            || ((__VALUE__) == LL_LPUART_DIRECTION_RX) \
91                                            || ((__VALUE__) == LL_LPUART_DIRECTION_TX) \
92                                            || ((__VALUE__) == LL_LPUART_DIRECTION_TX_RX))
93 
94 #define IS_LL_LPUART_PARITY(__VALUE__) (((__VALUE__) == LL_LPUART_PARITY_NONE) \
95                                         || ((__VALUE__) == LL_LPUART_PARITY_EVEN) \
96                                         || ((__VALUE__) == LL_LPUART_PARITY_ODD))
97 
98 #define IS_LL_LPUART_DATAWIDTH(__VALUE__) (((__VALUE__) == LL_LPUART_DATAWIDTH_7B) \
99                                            || ((__VALUE__) == LL_LPUART_DATAWIDTH_8B) \
100                                            || ((__VALUE__) == LL_LPUART_DATAWIDTH_9B))
101 
102 #define IS_LL_LPUART_STOPBITS(__VALUE__) (((__VALUE__) == LL_LPUART_STOPBITS_1) \
103                                           || ((__VALUE__) == LL_LPUART_STOPBITS_2))
104 
105 #define IS_LL_LPUART_HWCONTROL(__VALUE__) (((__VALUE__) == LL_LPUART_HWCONTROL_NONE) \
106                                            || ((__VALUE__) == LL_LPUART_HWCONTROL_RTS) \
107                                            || ((__VALUE__) == LL_LPUART_HWCONTROL_CTS) \
108                                            || ((__VALUE__) == LL_LPUART_HWCONTROL_RTS_CTS))
109 
110 /**
111   * @}
112   */
113 
114 /* Private function prototypes -----------------------------------------------*/
115 
116 /* Exported functions --------------------------------------------------------*/
117 /** @addtogroup LPUART_LL_Exported_Functions
118   * @{
119   */
120 
121 /** @addtogroup LPUART_LL_EF_Init
122   * @{
123   */
124 
125 /**
126   * @brief  De-initialize LPUART registers (Registers restored to their default values).
127   * @param  LPUARTx LPUART Instance
128   * @retval An ErrorStatus enumeration value:
129   *          - SUCCESS: LPUART registers are de-initialized
130   *          - ERROR: not applicable
131   */
LL_LPUART_DeInit(const USART_TypeDef * LPUARTx)132 ErrorStatus LL_LPUART_DeInit(const USART_TypeDef *LPUARTx)
133 {
134   ErrorStatus status = SUCCESS;
135 
136   /* Check the parameters */
137   assert_param(IS_LPUART_INSTANCE(LPUARTx));
138 
139   if (LPUARTx == LPUART1)
140   {
141     /* Force reset of LPUART peripheral */
142     LL_APB3_GRP1_ForceReset(LL_APB3_GRP1_PERIPH_LPUART1);
143 
144     /* Release reset of LPUART peripheral */
145     LL_APB3_GRP1_ReleaseReset(LL_APB3_GRP1_PERIPH_LPUART1);
146   }
147   else
148   {
149     status = ERROR;
150   }
151 
152   return (status);
153 }
154 
155 /**
156   * @brief  Initialize LPUART registers according to the specified
157   *         parameters in LPUART_InitStruct.
158   * @note   As some bits in LPUART configuration registers can only be written when
159   *         the LPUART is disabled (USART_CR1_UE bit =0),
160   *         LPUART Peripheral should be in disabled state prior calling this function.
161   *         Otherwise, ERROR result will be returned.
162   * @note   Baud rate value stored in LPUART_InitStruct BaudRate field, should be valid (different from 0).
163   * @param  LPUARTx LPUART Instance
164   * @param  LPUART_InitStruct pointer to a @ref LL_LPUART_InitTypeDef structure
165   *         that contains the configuration information for the specified LPUART peripheral.
166   * @retval An ErrorStatus enumeration value:
167   *          - SUCCESS: LPUART registers are initialized according to LPUART_InitStruct content
168   *          - ERROR: Problem occurred during LPUART Registers initialization
169   */
LL_LPUART_Init(USART_TypeDef * LPUARTx,const LL_LPUART_InitTypeDef * LPUART_InitStruct)170 ErrorStatus LL_LPUART_Init(USART_TypeDef *LPUARTx, const LL_LPUART_InitTypeDef *LPUART_InitStruct)
171 {
172   ErrorStatus status = ERROR;
173   uint32_t periphclk;
174 
175   /* Check the parameters */
176   assert_param(IS_LPUART_INSTANCE(LPUARTx));
177   assert_param(IS_LL_LPUART_PRESCALER(LPUART_InitStruct->PrescalerValue));
178   assert_param(IS_LL_LPUART_BAUDRATE(LPUART_InitStruct->BaudRate));
179   assert_param(IS_LL_LPUART_DATAWIDTH(LPUART_InitStruct->DataWidth));
180   assert_param(IS_LL_LPUART_STOPBITS(LPUART_InitStruct->StopBits));
181   assert_param(IS_LL_LPUART_PARITY(LPUART_InitStruct->Parity));
182   assert_param(IS_LL_LPUART_DIRECTION(LPUART_InitStruct->TransferDirection));
183   assert_param(IS_LL_LPUART_HWCONTROL(LPUART_InitStruct->HardwareFlowControl));
184 
185   /* LPUART needs to be in disabled state, in order to be able to configure some bits in
186      CRx registers. Otherwise (LPUART not in Disabled state) => return ERROR */
187   if (LL_LPUART_IsEnabled(LPUARTx) == 0U)
188   {
189     /*---------------------------- LPUART CR1 Configuration -----------------------
190      * Configure LPUARTx CR1 (LPUART Word Length, Parity and Transfer Direction bits) with parameters:
191      * - DataWidth:          USART_CR1_M bits according to LPUART_InitStruct->DataWidth value
192      * - Parity:             USART_CR1_PCE, USART_CR1_PS bits according to LPUART_InitStruct->Parity value
193      * - TransferDirection:  USART_CR1_TE, USART_CR1_RE bits according to LPUART_InitStruct->TransferDirection value
194      */
195     MODIFY_REG(LPUARTx->CR1,
196                (USART_CR1_M | USART_CR1_PCE | USART_CR1_PS | USART_CR1_TE | USART_CR1_RE),
197                (LPUART_InitStruct->DataWidth | LPUART_InitStruct->Parity | LPUART_InitStruct->TransferDirection));
198 
199     /*---------------------------- LPUART CR2 Configuration -----------------------
200      * Configure LPUARTx CR2 (Stop bits) with parameters:
201      * - Stop Bits:          USART_CR2_STOP bits according to LPUART_InitStruct->StopBits value.
202      */
203     LL_LPUART_SetStopBitsLength(LPUARTx, LPUART_InitStruct->StopBits);
204 
205     /*---------------------------- LPUART CR3 Configuration -----------------------
206      * Configure LPUARTx CR3 (Hardware Flow Control) with parameters:
207      * - HardwareFlowControl: USART_CR3_RTSE, USART_CR3_CTSE bits according
208      *   to LPUART_InitStruct->HardwareFlowControl value.
209      */
210     LL_LPUART_SetHWFlowCtrl(LPUARTx, LPUART_InitStruct->HardwareFlowControl);
211 
212     /*---------------------------- LPUART BRR Configuration -----------------------
213      * Retrieve Clock frequency used for LPUART Peripheral
214      */
215     periphclk = LL_RCC_GetLPUARTClockFreq(LL_RCC_LPUART1_CLKSOURCE);
216 
217     /* Configure the LPUART Baud Rate :
218        - prescaler value is required
219        - valid baud rate value (different from 0) is required
220        - Peripheral clock as returned by RCC service, should be valid (different from 0).
221     */
222     if ((periphclk != LL_RCC_PERIPH_FREQUENCY_NO)
223         && (LPUART_InitStruct->BaudRate != 0U))
224     {
225       status = SUCCESS;
226       LL_LPUART_SetBaudRate(LPUARTx,
227                             periphclk,
228                             LPUART_InitStruct->PrescalerValue,
229                             LPUART_InitStruct->BaudRate);
230 
231       /* Check BRR is greater than or equal to 0x300 */
232       assert_param(IS_LL_LPUART_BRR_MIN(LPUARTx->BRR));
233 
234       /* Check BRR is lower than or equal to 0xFFFFF */
235       assert_param(IS_LL_LPUART_BRR_MAX(LPUARTx->BRR));
236     }
237 
238     /*---------------------------- LPUART PRESC Configuration -----------------------
239      * Configure LPUARTx PRESC (Prescaler) with parameters:
240      * - PrescalerValue: LPUART_PRESC_PRESCALER bits according to LPUART_InitStruct->PrescalerValue value.
241      */
242     LL_LPUART_SetPrescaler(LPUARTx, LPUART_InitStruct->PrescalerValue);
243   }
244 
245   return (status);
246 }
247 
248 /**
249   * @brief Set each @ref LL_LPUART_InitTypeDef field to default value.
250   * @param LPUART_InitStruct pointer to a @ref LL_LPUART_InitTypeDef structure
251   *                          whose fields will be set to default values.
252   * @retval None
253   */
254 
LL_LPUART_StructInit(LL_LPUART_InitTypeDef * LPUART_InitStruct)255 void LL_LPUART_StructInit(LL_LPUART_InitTypeDef *LPUART_InitStruct)
256 {
257   /* Set LPUART_InitStruct fields to default values */
258   LPUART_InitStruct->PrescalerValue      = LL_LPUART_PRESCALER_DIV1;
259   LPUART_InitStruct->BaudRate            = LPUART_DEFAULT_BAUDRATE;
260   LPUART_InitStruct->DataWidth           = LL_LPUART_DATAWIDTH_8B;
261   LPUART_InitStruct->StopBits            = LL_LPUART_STOPBITS_1;
262   LPUART_InitStruct->Parity              = LL_LPUART_PARITY_NONE ;
263   LPUART_InitStruct->TransferDirection   = LL_LPUART_DIRECTION_TX_RX;
264   LPUART_InitStruct->HardwareFlowControl = LL_LPUART_HWCONTROL_NONE;
265 }
266 
267 /**
268   * @}
269   */
270 
271 /**
272   * @}
273   */
274 
275 /**
276   * @}
277   */
278 
279 #endif /* LPUART1 */
280 
281 /**
282   * @}
283   */
284 
285 #endif /* USE_FULL_LL_DRIVER */
286