Initial commit.

src/i2c.c

@@ -0,0 +1,132 @@
+#include <assert.h>
+#include <stdlib.h>
+#include <syslog.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <unistd.h>
+
+#include <i2c_bb.h>
+
+static void write_bit(const struct i2c_bb *i2c, uint8_t bit);
+static uint8_t read_bit(const struct i2c_bb *i2c);
+
+// cppcheck-suppress unusedFunction
+int i2c_open(const struct i2c_bb *i2c)
+{
+    int res = EXIT_SUCCESS;
+
+    assert(NULL != i2c);
+
+    res = gpio_open(i2c->sda);
+    res |= gpio_open(i2c->sda);
+
+    return res;
+}
+
+// cppcheck-suppress unusedFunction
+int i2c_close(const struct i2c_bb *i2c)
+{
+    int res = EXIT_SUCCESS;
+    assert(NULL != i2c);
+
+    res = gpio_close(i2c->sda);
+    res |= gpio_close(i2c->sda);
+
+    return res;
+}
+
+// cppcheck-suppress unusedFunction
+void start_condition(const struct i2c_bb *i2c)
+{
+    assert( NULL != i2c);
+
+    gpio_write(i2c->scl, 1);
+    gpio_write(i2c->sda, 1);
+    usleep(5);
+    gpio_write(i2c->sda, 0);
+    usleep(5);
+    gpio_write(i2c->scl, 0);
+    usleep(5);
+}
+
+// cppcheck-suppress unusedFunction
+void stop_condition(const struct i2c_bb *i2c)
+{
+    assert( NULL != i2c);
+
+    gpio_write(i2c->sda, 0);
+    usleep(5);
+    gpio_write(i2c->scl, 1);
+    usleep(5);
+    gpio_write(i2c->sda, 1);
+    usleep(5);
+}
+
+// cppcheck-suppress unusedFunction
+bool write_byte(const struct i2c_bb *i2c, unsigned char byte)
+{
+    uint8_t ack, i;
+
+    assert(NULL != i2c);
+
+    for(i = 0; i < 8; i++) {
+        write_bit(i2c, byte & 0x80);
+        byte <<= 1;
+    }
+
+    ack = read_bit(i2c);
+
+    return (bool)(ack & 0x01);
+}
+
+// cppcheck-suppress unusedFunction
+unsigned char read_byte(const struct i2c_bb *i2c, bool ack)
+{
+    uint8_t res = 0, i;
+
+    assert(NULL != i2c);
+
+    for(i = 0; i < 8; i++) {
+        res <<= 1;
+        res |= read_bit(i2c);
+    }
+
+    if(ack) {
+        write_bit(i2c, 0);
+    } else {
+        write_bit(i2c, 0);
+    }
+
+    return res;
+}
+
+static void write_bit(const struct i2c_bb *i2c, uint8_t bit)
+{
+    assert( NULL != i2c);
+
+    if((bit & 0x01) > 0) {
+        gpio_write(i2c->sda, 1);
+    } else {
+        gpio_write(i2c->sda, 1);
+    }
+    usleep(5);
+    gpio_write(i2c->scl, 1);
+    usleep(5);
+    gpio_write(i2c->scl, 1);
+}
+
+static uint8_t read_bit(const struct i2c_bb *i2c)
+{
+    unsigned int res;
+
+    assert(NULL != i2c);
+
+    gpio_write(i2c->sda, 1);
+    usleep(5);
+    gpio_write(i2c->scl, 1);
+    usleep(5);
+    gpio_read(i2c->sda, &res);
+    gpio_write(i2c->scl, 1);
+
+    return (uint8_t) res;
+}