/* * geany_encoding=koi8-r * i2c.c * * Copyright 2017 Edward V. Emelianov * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, * MA 02110-1301, USA. * */ #include "hardware.h" #include "i2c.h" #include "proto.h" #include "usb.h" I2C_SPEED curI2Cspeed = LOW_SPEED; extern volatile uint32_t Tms; static uint32_t cntr; volatile uint8_t I2C_scan_mode = 0; // == 1 when I2C is in scan mode static uint8_t i2caddr = I2C_ADDREND; // not active void i2c_setup(I2C_SPEED speed){ if(speed >= CURRENT_SPEED){ speed = curI2Cspeed; }else{ curI2Cspeed = speed; } I2C1->CR1 = 0; /* * GPIO Resources: I2C1_SCL - PB6, I2C1_SDA - PB7 (AF1) */ GPIOB->AFR[0] = (GPIOB->AFR[0] & ~(GPIO_AFRL_AFRL6 | GPIO_AFRL_AFRL7)) | 1 << (6 * 4) | 1 << (7 * 4); GPIOB->MODER = (GPIOB->MODER & ~(GPIO_MODER_MODER6 | GPIO_MODER_MODER7)) | GPIO_MODER_MODER6_AF | GPIO_MODER_MODER7_AF; GPIOB->OTYPER |= GPIO_OTYPER_OT_6 | GPIO_OTYPER_OT_7; // both open-drain outputs // I2C RCC->APB1ENR |= RCC_APB1ENR_I2C1EN; // timing RCC->CFGR3 |= RCC_CFGR3_I2C1SW; // use sysclock for timing if(speed == LOW_SPEED){ // 10kHz // PRESC=B, SCLDEL=4, SDADEL=2, SCLH=0xC3, SCLL=0xB0 I2C1->TIMINGR = (0xB<<28) | (4<<20) | (2<<16) | (0xC3<<8) | (0xB0); }else if(speed == HIGH_SPEED){ // 100kHz I2C1->TIMINGR = (0xB<<28) | (4<<20) | (2<<16) | (0x12<<8) | (0x11); }else{ // VERYLOW_SPEED - the lowest speed by STM register: 5.8kHz (presc = 16-1 = 15; ) I2C1->TIMINGR = (0xf<<28) | (4<<20) | (2<<16) | (0xff<<8) | (0xff); } I2C1->CR1 = I2C_CR1_PE; } /** * write command byte to I2C * @param addr - device address (TSYS01_ADDR0 or TSYS01_ADDR1) * @param data - bytes to write * @param nbytes - amount of bytes to write * @param stop - to set STOP * @return 0 if error */ static uint8_t write_i2cs(uint8_t addr, uint8_t *data, uint8_t nbytes, uint8_t stop){ cntr = Tms; I2C1->CR1 = 0; // clear busy flag I2C1->ICR = 0x3f38; // clear all errors I2C1->CR1 = I2C_CR1_PE; while(I2C1->ISR & I2C_ISR_BUSY){ IWDG->KR = IWDG_REFRESH; if(Tms - cntr > I2C_TIMEOUT){ USND("Line busy\n"); return 0; // check busy }} cntr = Tms; while(I2C1->CR2 & I2C_CR2_START){ IWDG->KR = IWDG_REFRESH; if(Tms - cntr > I2C_TIMEOUT){ return 0; // check start }} //I2C1->ICR = 0x3f38; // clear all errors I2C1->CR2 = nbytes << 16 | addr; if(stop) I2C1->CR2 |= I2C_CR2_AUTOEND; // autoend // now start transfer I2C1->CR2 |= I2C_CR2_START; for(int i = 0; i < nbytes; ++i){ cntr = Tms; while(!(I2C1->ISR & I2C_ISR_TXIS)){ // ready to transmit IWDG->KR = IWDG_REFRESH; if(I2C1->ISR & I2C_ISR_NACKF){ I2C1->ICR |= I2C_ICR_NACKCF; USND("NAK\n"); return 0; } if(Tms - cntr > I2C_TIMEOUT){ USND("Timeout\n"); return 0; } } I2C1->TXDR = data[i]; // send data } // wait for data gone while(I2C1->ISR & I2C_ISR_BUSY){ IWDG->KR = IWDG_REFRESH; if(Tms - cntr > I2C_TIMEOUT){break;} } return 1; } uint8_t write_i2c(uint8_t addr, uint8_t *data, uint8_t nbytes){ return write_i2cs(addr, data, nbytes, 1); } /** * read nbytes of data from I2C line * `data` should be an array with at least `nbytes` length * @return 1 if all OK, 0 if NACK or no device found */ static uint8_t read_i2cb(uint8_t addr, uint8_t *data, uint8_t nbytes, uint8_t busychk){ if(busychk){ cntr = Tms; while(I2C1->ISR & I2C_ISR_BUSY){ IWDG->KR = IWDG_REFRESH; if(Tms - cntr > I2C_TIMEOUT){ USND("Line busy\n"); return 0; // check busy }} } cntr = Tms; while(I2C1->CR2 & I2C_CR2_START){ IWDG->KR = IWDG_REFRESH; if(Tms - cntr > I2C_TIMEOUT){ USND("No start\n"); return 0; // check start }} // read N bytes I2C1->CR2 = (nbytes<<16) | addr | 1 | I2C_CR2_AUTOEND | I2C_CR2_RD_WRN; I2C1->CR2 |= I2C_CR2_START; uint8_t i; for(i = 0; i < nbytes; ++i){ cntr = Tms; while(!(I2C1->ISR & I2C_ISR_RXNE)){ // wait for data IWDG->KR = IWDG_REFRESH; if(I2C1->ISR & I2C_ISR_NACKF){ I2C1->ICR |= I2C_ICR_NACKCF; USND("NAK\n"); return 0; } if(Tms - cntr > I2C_TIMEOUT){ USND("Timeout\n"); return 0; } } *data++ = I2C1->RXDR; } return 1; } uint8_t read_i2c(uint8_t addr, uint8_t *data, uint8_t nbytes){ return read_i2cb(addr, data, nbytes, 1); } // read register reg uint8_t read_i2c_reg(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t nbytes){ if(!write_i2cs(addr, ®, 1, 0)) return 0; return read_i2cb(addr, data, nbytes, 0); } void i2c_init_scan_mode(){ i2caddr = 0; I2C_scan_mode = 1; } // return 1 if next addr is active & return in as `addr` // if addresses are over, return 1 and set addr to I2C_NOADDR // if scan mode inactive, return 0 and set addr to I2C_NOADDR int i2c_scan_next_addr(uint8_t *addr){ *addr = i2caddr; if(i2caddr == I2C_ADDREND){ *addr = I2C_ADDREND; I2C_scan_mode = 0; return 0; } if(!read_i2c_reg((i2caddr++)<<1, 0, NULL, 0)) return 0; return 1; }