A27系列优化I2C/RTC处理，新增版本A270Y

A27-STEPLDR/Src/i2c.c

@@ -0,0 +1,72 @@
+#include <string.h>
+#include "FreeRTOS.h"
+#include "amt630h.h"
+#include "board.h"
+#include "timer.h"
+#include "i2c.h"
+#include "i2c-gpio.h"
+
+
+#ifdef I2C_SUPPORT
+#define MAX_I2C_DEVICE_NUM		4
+
+static struct i2c_adapter *i2c_devs[MAX_I2C_DEVICE_NUM] = {NULL};
+static int i2c_devices_count = 0;
+
+int i2c_add_adapter(struct i2c_adapter *adap)
+{
+	if (i2c_devices_count >= MAX_I2C_DEVICE_NUM)
+		return -1;
+
+	/* Set default timeout to 1 second if not already set */
+	if (adap->timeout == 0)
+		adap->timeout = configTICK_RATE_HZ;
+
+	i2c_devs[i2c_devices_count++] = adap;
+
+	return 0;
+}
+
+struct i2c_adapter *i2c_open(const char *i2cdev)
+{
+	struct i2c_adapter *adap;
+	int i;
+
+	for (i = 0; i < i2c_devices_count; i++) {
+		adap = i2c_devs[i];
+		if (!strcmp(adap->name, i2cdev)) {
+			adap->open_count++;
+			return adap;
+		}
+	}
+
+	return NULL;
+}
+
+int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	unsigned long orig_jiffies;
+	int ret, try;
+
+	configASSERT(adap && msgs);
+
+	/* Retry automatically on arbitration loss */
+	orig_jiffies = get_timer(0);
+	for (ret = 0, try = 0; try <= adap->retries; try++) {
+		ret = adap->algo->master_xfer(adap, msgs, num);
+		if (ret != -EAGAIN)
+			break;
+		if (get_timer(orig_jiffies) > adap->timeout)
+			break;
+	}
+
+	return ret;
+}
+
+void i2c_init(void)
+{
+#ifdef ANALOG_I2C_SUPPORT
+	i2c_gpio_init();
+#endif
+}
+#endif