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| 1 | +/* mbed Microcontroller Library |
| 2 | + * SPDX-License-Identifier: BSD-3-Clause |
| 3 | + ****************************************************************************** |
| 4 | + * |
| 5 | + * Copyright (c) 2021 STMicroelectronics. |
| 6 | + * All rights reserved. |
| 7 | + * |
| 8 | + * This software component is licensed by ST under BSD 3-Clause license, |
| 9 | + * the "License"; You may not use this file except in compliance with the |
| 10 | + * License. You may obtain a copy of the License at: |
| 11 | + * opensource.org/licenses/BSD-3-Clause |
| 12 | + * |
| 13 | + ****************************************************************************** |
| 14 | + */ |
| 15 | + |
| 16 | +#include "i2c_device.h" |
| 17 | +#include "mbed_assert.h" |
| 18 | +#include "mbed_error.h" |
| 19 | +#include "stm32f3xx_ll_rcc.h" |
| 20 | + |
| 21 | +/* Define I2C Device */ |
| 22 | +#if DEVICE_I2C |
| 23 | + |
| 24 | +/** |
| 25 | + * @brief Get I2C clock source frequency according I2C instance used. |
| 26 | + * @param i2c I2C instance name. |
| 27 | + * @retval I2C clock source frequency in Hz. |
| 28 | + */ |
| 29 | +uint32_t i2c_get_pclk(I2CName i2c) |
| 30 | +{ |
| 31 | + uint32_t clocksource; |
| 32 | + uint32_t pclk = 0; |
| 33 | + if (i2c == I2C_1) { |
| 34 | + clocksource = __HAL_RCC_GET_I2C1_SOURCE(); |
| 35 | + switch (clocksource) { |
| 36 | + case RCC_I2C1CLKSOURCE_SYSCLK: |
| 37 | + pclk = HAL_RCC_GetSysClockFreq(); |
| 38 | + break; |
| 39 | + |
| 40 | + case RCC_I2C1CLKSOURCE_HSI: |
| 41 | + pclk = HSI_VALUE; |
| 42 | + break; |
| 43 | + } |
| 44 | + } |
| 45 | +#if defined I2C2_BASE |
| 46 | + else if (i2c == I2C_2) { |
| 47 | + clocksource = __HAL_RCC_GET_I2C2_SOURCE(); |
| 48 | + switch (clocksource) { |
| 49 | + case RCC_I2C2CLKSOURCE_SYSCLK: |
| 50 | + pclk = HAL_RCC_GetSysClockFreq(); |
| 51 | + break; |
| 52 | + |
| 53 | + case RCC_I2C2CLKSOURCE_HSI: |
| 54 | + pclk = HSI_VALUE; |
| 55 | + break; |
| 56 | + } |
| 57 | + } |
| 58 | +#endif |
| 59 | +#if defined I2C3_BASE |
| 60 | + else if (i2c == I2C_3) { |
| 61 | + clocksource = __HAL_RCC_GET_I2C3_SOURCE(); |
| 62 | + switch (clocksource) { |
| 63 | + case RCC_I2C3CLKSOURCE_SYSCLK: |
| 64 | + pclk = HAL_RCC_GetSysClockFreq(); |
| 65 | + break; |
| 66 | + |
| 67 | + case RCC_I2C3CLKSOURCE_HSI: |
| 68 | + pclk = HSI_VALUE; |
| 69 | + break; |
| 70 | + } |
| 71 | + } |
| 72 | +#endif |
| 73 | + else { |
| 74 | + // should not happend |
| 75 | + error("I2C: unknown instance"); |
| 76 | + } |
| 77 | + return pclk; |
| 78 | +} |
| 79 | + |
| 80 | +/** |
| 81 | + * @brief Provide the suitable timing depending on requested frequency |
| 82 | + * @param hz Required I2C clock in Hz. |
| 83 | + * @retval I2C timing or 0 in case of error. |
| 84 | + */ |
| 85 | +uint32_t i2c_get_timing(I2CName i2c, int hz) |
| 86 | +{ |
| 87 | + uint32_t tim; |
| 88 | + uint32_t pclk; |
| 89 | + |
| 90 | + pclk = i2c_get_pclk(i2c); |
| 91 | + |
| 92 | + if (pclk == I2C_PCLK_HSI) { |
| 93 | + switch (hz) { |
| 94 | + case 100000: |
| 95 | + tim = TIMING_VAL_64M_CLK_100KHZ; |
| 96 | + break; |
| 97 | + case 400000: |
| 98 | + tim = TIMING_VAL_64M_CLK_400KHZ; |
| 99 | + break; |
| 100 | + case 1000000: |
| 101 | + tim = TIMING_VAL_64M_CLK_1MHZ; |
| 102 | + break; |
| 103 | + default: |
| 104 | + MBED_ASSERT((hz == 100000) || (hz == 400000) || (hz == 1000000)); |
| 105 | + break; |
| 106 | + } |
| 107 | + } else if (pclk == I2C_PCLK_HSE) { |
| 108 | + switch (hz) { |
| 109 | + case 100000: |
| 110 | + tim = TIMING_VAL_72M_CLK_100KHZ; |
| 111 | + break; |
| 112 | + case 400000: |
| 113 | + tim = TIMING_VAL_72M_CLK_400KHZ; |
| 114 | + break; |
| 115 | + case 1000000: |
| 116 | + tim = TIMING_VAL_72M_CLK_1MHZ; |
| 117 | + break; |
| 118 | + default: |
| 119 | + MBED_ASSERT((hz == 100000) || (hz == 400000) || (hz == 1000000)); |
| 120 | + break; |
| 121 | + } |
| 122 | + } |
| 123 | + |
| 124 | + else { |
| 125 | + tim = i2c_compute_timing(pclk, hz); |
| 126 | + } |
| 127 | + return tim; |
| 128 | +} |
| 129 | + |
| 130 | +/** |
| 131 | + * @} |
| 132 | + */ |
| 133 | + |
| 134 | +#endif // DEVICE_I2C |
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