1 /**
2 ******************************************************************************
3 * @file stm32l4xx_ll_lpuart.c
4 * @author MCD Application Team
5 * @brief LPUART LL module driver.
6 ******************************************************************************
7 * @attention
8 *
9 * Copyright (c) 2017 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 "stm32l4xx_ll_lpuart.h"
22 #include "stm32l4xx_ll_rcc.h"
23 #include "stm32l4xx_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 STM32L4xx_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 #if defined(USART_PRESC_PRESCALER)
63 #define IS_LL_LPUART_PRESCALER(__VALUE__) (((__VALUE__) == LL_LPUART_PRESCALER_DIV1) \
64 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV2) \
65 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV4) \
66 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV6) \
67 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV8) \
68 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV10) \
69 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV12) \
70 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV16) \
71 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV32) \
72 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV64) \
73 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV128) \
74 || ((__VALUE__) == LL_LPUART_PRESCALER_DIV256))
75
76 #endif /* USART_PRESC_PRESCALER */
77 /* __BAUDRATE__ Depending on constraints applicable for LPUART BRR register */
78 /* value : */
79 /* - fck must be in the range [3 x baudrate, 4096 x baudrate] */
80 /* - LPUART_BRR register value should be >= 0x300 */
81 /* - LPUART_BRR register value should be <= 0xFFFFF (20 bits) */
82 /* Baudrate specified by the user should belong to [8, 40000000].*/
83 #define IS_LL_LPUART_BAUDRATE(__BAUDRATE__) (((__BAUDRATE__) <= 40000000U) && ((__BAUDRATE__) >= 8U))
84
85 /* __VALUE__ BRR content must be greater than or equal to 0x300. */
86 #define IS_LL_LPUART_BRR_MIN(__VALUE__) ((__VALUE__) >= 0x300U)
87
88 /* __VALUE__ BRR content must be lower than or equal to 0xFFFFF. */
89 #define IS_LL_LPUART_BRR_MAX(__VALUE__) ((__VALUE__) <= 0x000FFFFFU)
90
91 #define IS_LL_LPUART_DIRECTION(__VALUE__) (((__VALUE__) == LL_LPUART_DIRECTION_NONE) \
92 || ((__VALUE__) == LL_LPUART_DIRECTION_RX) \
93 || ((__VALUE__) == LL_LPUART_DIRECTION_TX) \
94 || ((__VALUE__) == LL_LPUART_DIRECTION_TX_RX))
95
96 #define IS_LL_LPUART_PARITY(__VALUE__) (((__VALUE__) == LL_LPUART_PARITY_NONE) \
97 || ((__VALUE__) == LL_LPUART_PARITY_EVEN) \
98 || ((__VALUE__) == LL_LPUART_PARITY_ODD))
99
100 #define IS_LL_LPUART_DATAWIDTH(__VALUE__) (((__VALUE__) == LL_LPUART_DATAWIDTH_7B) \
101 || ((__VALUE__) == LL_LPUART_DATAWIDTH_8B) \
102 || ((__VALUE__) == LL_LPUART_DATAWIDTH_9B))
103
104 #define IS_LL_LPUART_STOPBITS(__VALUE__) (((__VALUE__) == LL_LPUART_STOPBITS_1) \
105 || ((__VALUE__) == LL_LPUART_STOPBITS_2))
106
107 #define IS_LL_LPUART_HWCONTROL(__VALUE__) (((__VALUE__) == LL_LPUART_HWCONTROL_NONE) \
108 || ((__VALUE__) == LL_LPUART_HWCONTROL_RTS) \
109 || ((__VALUE__) == LL_LPUART_HWCONTROL_CTS) \
110 || ((__VALUE__) == LL_LPUART_HWCONTROL_RTS_CTS))
111
112 /**
113 * @}
114 */
115
116 /* Private function prototypes -----------------------------------------------*/
117
118 /* Exported functions --------------------------------------------------------*/
119 /** @addtogroup LPUART_LL_Exported_Functions
120 * @{
121 */
122
123 /** @addtogroup LPUART_LL_EF_Init
124 * @{
125 */
126
127 /**
128 * @brief De-initialize LPUART registers (Registers restored to their default values).
129 * @param LPUARTx LPUART Instance
130 * @retval An ErrorStatus enumeration value:
131 * - SUCCESS: LPUART registers are de-initialized
132 * - ERROR: not applicable
133 */
LL_LPUART_DeInit(const USART_TypeDef * LPUARTx)134 ErrorStatus LL_LPUART_DeInit(const USART_TypeDef *LPUARTx)
135 {
136 ErrorStatus status = SUCCESS;
137
138 /* Check the parameters */
139 assert_param(IS_LPUART_INSTANCE(LPUARTx));
140
141 if (LPUARTx == LPUART1)
142 {
143 /* Force reset of LPUART peripheral */
144 LL_APB1_GRP2_ForceReset(LL_APB1_GRP2_PERIPH_LPUART1);
145
146 /* Release reset of LPUART peripheral */
147 LL_APB1_GRP2_ReleaseReset(LL_APB1_GRP2_PERIPH_LPUART1);
148 }
149 else
150 {
151 status = ERROR;
152 }
153
154 return (status);
155 }
156
157 /**
158 * @brief Initialize LPUART registers according to the specified
159 * parameters in LPUART_InitStruct.
160 * @note As some bits in LPUART configuration registers can only be written when
161 * the LPUART is disabled (USART_CR1_UE bit =0),
162 * LPUART Peripheral should be in disabled state prior calling this function.
163 * Otherwise, ERROR result will be returned.
164 * @note Baud rate value stored in LPUART_InitStruct BaudRate field, should be valid (different from 0).
165 * @param LPUARTx LPUART Instance
166 * @param LPUART_InitStruct pointer to a @ref LL_LPUART_InitTypeDef structure
167 * that contains the configuration information for the specified LPUART peripheral.
168 * @retval An ErrorStatus enumeration value:
169 * - SUCCESS: LPUART registers are initialized according to LPUART_InitStruct content
170 * - ERROR: Problem occurred during LPUART Registers initialization
171 */
LL_LPUART_Init(USART_TypeDef * LPUARTx,const LL_LPUART_InitTypeDef * LPUART_InitStruct)172 ErrorStatus LL_LPUART_Init(USART_TypeDef *LPUARTx, const LL_LPUART_InitTypeDef *LPUART_InitStruct)
173 {
174 ErrorStatus status = ERROR;
175 uint32_t periphclk;
176
177 /* Check the parameters */
178 assert_param(IS_LPUART_INSTANCE(LPUARTx));
179 #if defined(USART_PRESC_PRESCALER)
180 assert_param(IS_LL_LPUART_PRESCALER(LPUART_InitStruct->PrescalerValue));
181 #endif /* USART_PRESC_PRESCALER */
182 assert_param(IS_LL_LPUART_BAUDRATE(LPUART_InitStruct->BaudRate));
183 assert_param(IS_LL_LPUART_DATAWIDTH(LPUART_InitStruct->DataWidth));
184 assert_param(IS_LL_LPUART_STOPBITS(LPUART_InitStruct->StopBits));
185 assert_param(IS_LL_LPUART_PARITY(LPUART_InitStruct->Parity));
186 assert_param(IS_LL_LPUART_DIRECTION(LPUART_InitStruct->TransferDirection));
187 assert_param(IS_LL_LPUART_HWCONTROL(LPUART_InitStruct->HardwareFlowControl));
188
189 /* LPUART needs to be in disabled state, in order to be able to configure some bits in
190 CRx registers. Otherwise (LPUART not in Disabled state) => return ERROR */
191 if (LL_LPUART_IsEnabled(LPUARTx) == 0U)
192 {
193 /*---------------------------- LPUART CR1 Configuration -----------------------
194 * Configure LPUARTx CR1 (LPUART Word Length, Parity and Transfer Direction bits) with parameters:
195 * - DataWidth: USART_CR1_M bits according to LPUART_InitStruct->DataWidth value
196 * - Parity: USART_CR1_PCE, USART_CR1_PS bits according to LPUART_InitStruct->Parity value
197 * - TransferDirection: USART_CR1_TE, USART_CR1_RE bits according to LPUART_InitStruct->TransferDirection value
198 */
199 MODIFY_REG(LPUARTx->CR1,
200 (USART_CR1_M | USART_CR1_PCE | USART_CR1_PS | USART_CR1_TE | USART_CR1_RE),
201 (LPUART_InitStruct->DataWidth | LPUART_InitStruct->Parity | LPUART_InitStruct->TransferDirection));
202
203 /*---------------------------- LPUART CR2 Configuration -----------------------
204 * Configure LPUARTx CR2 (Stop bits) with parameters:
205 * - Stop Bits: USART_CR2_STOP bits according to LPUART_InitStruct->StopBits value.
206 */
207 LL_LPUART_SetStopBitsLength(LPUARTx, LPUART_InitStruct->StopBits);
208
209 /*---------------------------- LPUART CR3 Configuration -----------------------
210 * Configure LPUARTx CR3 (Hardware Flow Control) with parameters:
211 * - HardwareFlowControl: USART_CR3_RTSE, USART_CR3_CTSE bits according
212 * to LPUART_InitStruct->HardwareFlowControl value.
213 */
214 LL_LPUART_SetHWFlowCtrl(LPUARTx, LPUART_InitStruct->HardwareFlowControl);
215
216 /*---------------------------- LPUART BRR Configuration -----------------------
217 * Retrieve Clock frequency used for LPUART Peripheral
218 */
219 periphclk = LL_RCC_GetLPUARTClockFreq(LL_RCC_LPUART1_CLKSOURCE);
220
221 /* Configure the LPUART Baud Rate :
222 #if defined(USART_PRESC_PRESCALER)
223 - prescaler value is required
224 #endif
225 - valid baud rate value (different from 0) is required
226 - Peripheral clock as returned by RCC service, should be valid (different from 0).
227 */
228 if ((periphclk != LL_RCC_PERIPH_FREQUENCY_NO)
229 && (LPUART_InitStruct->BaudRate != 0U))
230 {
231 status = SUCCESS;
232 LL_LPUART_SetBaudRate(LPUARTx,
233 periphclk,
234 #if defined(USART_PRESC_PRESCALER)
235 LPUART_InitStruct->PrescalerValue,
236 #endif /* USART_PRESC_PRESCALER */
237 LPUART_InitStruct->BaudRate);
238
239 /* Check BRR is greater than or equal to 0x300 */
240 assert_param(IS_LL_LPUART_BRR_MIN(LPUARTx->BRR));
241
242 /* Check BRR is lower than or equal to 0xFFFFF */
243 assert_param(IS_LL_LPUART_BRR_MAX(LPUARTx->BRR));
244 }
245
246 #if defined(USART_PRESC_PRESCALER)
247 /*---------------------------- LPUART PRESC Configuration -----------------------
248 * Configure LPUARTx PRESC (Prescaler) with parameters:
249 * - PrescalerValue: LPUART_PRESC_PRESCALER bits according to LPUART_InitStruct->PrescalerValue value.
250 */
251 LL_LPUART_SetPrescaler(LPUARTx, LPUART_InitStruct->PrescalerValue);
252 #endif /* USART_PRESC_PRESCALER */
253 }
254
255 return (status);
256 }
257
258 /**
259 * @brief Set each @ref LL_LPUART_InitTypeDef field to default value.
260 * @param LPUART_InitStruct pointer to a @ref LL_LPUART_InitTypeDef structure
261 * whose fields will be set to default values.
262 * @retval None
263 */
264
LL_LPUART_StructInit(LL_LPUART_InitTypeDef * LPUART_InitStruct)265 void LL_LPUART_StructInit(LL_LPUART_InitTypeDef *LPUART_InitStruct)
266 {
267 /* Set LPUART_InitStruct fields to default values */
268 #if defined(USART_PRESC_PRESCALER)
269 LPUART_InitStruct->PrescalerValue = LL_LPUART_PRESCALER_DIV1;
270 #endif /* USART_PRESC_PRESCALER */
271 LPUART_InitStruct->BaudRate = LPUART_DEFAULT_BAUDRATE;
272 LPUART_InitStruct->DataWidth = LL_LPUART_DATAWIDTH_8B;
273 LPUART_InitStruct->StopBits = LL_LPUART_STOPBITS_1;
274 LPUART_InitStruct->Parity = LL_LPUART_PARITY_NONE ;
275 LPUART_InitStruct->TransferDirection = LL_LPUART_DIRECTION_TX_RX;
276 LPUART_InitStruct->HardwareFlowControl = LL_LPUART_HWCONTROL_NONE;
277 }
278
279 /**
280 * @}
281 */
282
283 /**
284 * @}
285 */
286
287 /**
288 * @}
289 */
290
291 #endif /* LPUART1 */
292
293 /**
294 * @}
295 */
296
297 #endif /* USE_FULL_LL_DRIVER */
298
