mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-22 14:28:07 +00:00
125 lines
3.8 KiB
C
125 lines
3.8 KiB
C
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#include STM32_HAL_H
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#include "i2c.h"
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#include "common.h"
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static I2C_HandleTypeDef i2c_handle;
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void HAL_I2C_MspInit(I2C_HandleTypeDef *hi2c) {
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// enable I2C clock
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__HAL_RCC_I2C1_CLK_ENABLE();
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// GPIO have already been initialised by touch_init
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}
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void HAL_I2C_MspDeInit(I2C_HandleTypeDef *hi2c) {
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__HAL_RCC_I2C1_CLK_DISABLE();
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}
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void i2c_init(void) {
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if (i2c_handle.Instance) {
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return;
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}
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GPIO_InitTypeDef GPIO_InitStructure;
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// configure CTP I2C SCL and SDA GPIO lines (PB6 & PB7)
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GPIO_InitStructure.Mode = GPIO_MODE_AF_OD;
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GPIO_InitStructure.Pull = GPIO_NOPULL;
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GPIO_InitStructure.Speed =
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GPIO_SPEED_FREQ_LOW; // I2C is a KHz bus and low speed is still good into
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// the low MHz
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GPIO_InitStructure.Alternate = GPIO_AF4_I2C1;
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GPIO_InitStructure.Pin = GPIO_PIN_6 | GPIO_PIN_7;
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HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);
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i2c_handle.Instance = I2C1;
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i2c_handle.Init.ClockSpeed = 200000;
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i2c_handle.Init.DutyCycle = I2C_DUTYCYCLE_16_9;
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i2c_handle.Init.OwnAddress1 = 0xFE; // master
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i2c_handle.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
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i2c_handle.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
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i2c_handle.Init.OwnAddress2 = 0;
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i2c_handle.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
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i2c_handle.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
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if (HAL_OK != HAL_I2C_Init(&i2c_handle)) {
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ensure(secfalse, "I2C was not loaded properly.");
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return;
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}
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}
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void _i2c_deinit(void) {
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if (i2c_handle.Instance) {
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HAL_I2C_DeInit(&i2c_handle);
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i2c_handle.Instance = NULL;
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}
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}
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void _i2c_ensure_pin(uint16_t GPIO_Pin, GPIO_PinState PinState) {
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HAL_GPIO_WritePin(GPIOB, GPIO_Pin, PinState);
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while (HAL_GPIO_ReadPin(GPIOB, GPIO_Pin) != PinState)
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;
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}
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// I2C cycle described in section 2.9.7 of STM CD00288116 Errata sheet
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//
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// https://www.st.com/content/ccc/resource/technical/document/errata_sheet/7f/05/b0/bc/34/2f/4c/21/CD00288116.pdf/files/CD00288116.pdf/jcr:content/translations/en.CD00288116.pdf
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void i2c_cycle(void) {
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// PIN6 is SCL, PIN7 is SDA
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// 1. Disable I2C peripheral
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_i2c_deinit();
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// 2. Configure SCL/SDA as GPIO OUTPUT Open Drain
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GPIO_InitTypeDef GPIO_InitStructure;
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GPIO_InitStructure.Mode = GPIO_MODE_OUTPUT_OD;
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GPIO_InitStructure.Pull = GPIO_NOPULL;
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GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_LOW;
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GPIO_InitStructure.Pin = GPIO_PIN_6 | GPIO_PIN_7;
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HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);
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HAL_Delay(50);
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// 3. Check SCL and SDA High level
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_i2c_ensure_pin(GPIO_PIN_6, GPIO_PIN_SET);
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_i2c_ensure_pin(GPIO_PIN_7, GPIO_PIN_SET);
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// 4+5. Check SDA Low level
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_i2c_ensure_pin(GPIO_PIN_7, GPIO_PIN_RESET);
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// 6+7. Check SCL Low level
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_i2c_ensure_pin(GPIO_PIN_6, GPIO_PIN_RESET);
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// 8+9. Check SCL High level
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_i2c_ensure_pin(GPIO_PIN_6, GPIO_PIN_SET);
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// 10+11. Check SDA High level
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_i2c_ensure_pin(GPIO_PIN_7, GPIO_PIN_SET);
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// 12. Configure SCL/SDA as Alternate function Open-Drain
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GPIO_InitStructure.Mode = GPIO_MODE_AF_OD;
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GPIO_InitStructure.Pull = GPIO_NOPULL;
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GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_LOW;
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GPIO_InitStructure.Alternate = GPIO_AF4_I2C1;
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GPIO_InitStructure.Pin = GPIO_PIN_6 | GPIO_PIN_7;
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HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);
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HAL_Delay(50);
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// 13. Set SWRST bit in I2Cx_CR1 register
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__HAL_RCC_I2C1_FORCE_RESET();
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HAL_Delay(50);
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// 14. Clear SWRST bit in I2Cx_CR1 register
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__HAL_RCC_I2C1_RELEASE_RESET();
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// 15. Enable the I2C peripheral
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i2c_init();
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HAL_Delay(10);
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}
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HAL_StatusTypeDef i2c_transmit(uint8_t addr, uint8_t *data, uint16_t len,
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uint32_t timeout) {
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return HAL_I2C_Master_Transmit(&i2c_handle, addr, data, len, timeout);
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}
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HAL_StatusTypeDef i2c_receive(uint8_t addr, uint8_t *data, uint16_t len,
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uint32_t timeout) {
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return HAL_I2C_Master_Receive(&i2c_handle, addr, data, len, timeout);
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}
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