restructuring

F0:F030,F042,F072/TM1637/i2c.c

@@ -0,0 +1,105 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * i2c.c
+ *
+ * Copyright 2017 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * 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 "stm32f0.h"
+#include "hardware.h"
+#include "i2c.h"
+#include "usart.h"
+
+static uint32_t cntr;
+
+static uint8_t wri2c(uint8_t byte){
+    I2C1->CR2 = byte;// | I2C_CR2_AUTOEND;
+    if(byte & 1) I2C1->CR2 |= I2C_CR2_RD_WRN;
+    // now start transfer
+    I2C1->CR2 |= I2C_CR2_START;
+    if(I2C1->ISR & I2C_ISR_RXNE) (void) I2C1->RXDR;
+    cntr = Tms;
+    while((I2C1->ISR & I2C_ISR_TC) == 0) if(Tms - cntr > I2C_TIMEOUT) return 0;
+    if(I2C1->ISR & I2C_ISR_RXNE) (void) I2C1->RXDR;
+    I2C1->ICR = 0xff; // clear all error flags
+    return 1;
+}
+
+/**
+ * write command byte to I2C
+ * @param addr - device address (TSYS01_ADDR0 or TSYS01_ADDR1)
+ * @param data - byte to write
+ * @return 0 if error
+ */
+uint8_t write_i2c(const uint8_t *commands, uint8_t nbytes){
+    uint8_t r = 1;
+    cntr = Tms;
+    while(I2C1->ISR & I2C_ISR_BUSY) if(Tms - cntr > I2C_TIMEOUT) return 0;  // check busy
+    cntr = Tms;
+    while(I2C1->CR2 & I2C_CR2_START) if(Tms - cntr > I2C_TIMEOUT) return 0; // check start
+    for(uint8_t i = 0; i < nbytes; ++i){
+        if(!wri2c(commands[i])){
+            r = 0;
+            break;
+        }
+    }
+    I2C1->CR2 |= I2C_CR2_STOP;
+    return r;
+}
+
+/**
+ * read nbytes (0..4) of data from I2C line
+ * @return 1 if all OK, 0 if NACK or no device found
+ */
+uint8_t read_i2c(uint8_t command, uint8_t *data){
+    cntr = Tms;
+    while(I2C1->ISR & I2C_ISR_BUSY) if(Tms - cntr > 5) return 0;  // check busy
+    cntr = Tms;
+    while(I2C1->CR2 & I2C_CR2_START) if(Tms - cntr > 5) return 0; // check start
+    // read 1 byte
+    if(command & 1){
+        I2C1->CR2 = (1<<16) | command | I2C_CR2_RD_WRN;
+    }else{
+        wri2c(command);
+        /*
+        I2C1->CR2 = command;
+        I2C1->CR2 |= I2C_CR2_START;
+        cntr = Tms;
+        while((I2C1->ISR & I2C_ISR_TC) == 0) if(Tms - cntr > I2C_TIMEOUT) return 0;
+        */
+        I2C1->CR2 = (1<<16) |0xff | I2C_CR2_RD_WRN;
+    }
+    I2C1->CR2 |= I2C_CR2_START;
+    I2C1->CR2 |= I2C_CR2_STOP;
+    cntr = Tms;
+    while(Tms == cntr);
+/*
+    while(!(I2C1->ISR & I2C_ISR_RXNE)){ // wait for data
+        if(I2C1->ISR & I2C_ISR_NACKF){
+            I2C1->ICR |= I2C_ICR_NACKCF;
+            return 0;
+        }
+        if(Tms - cntr > 5) return 0;
+    }
+*/
+    if(I2C1->ISR & I2C_ISR_RXNE){
+        *data = I2C1->RXDR;
+        return 1;
+    }
+    return 0;
+ }