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-rw-r--r--src/device/i2c.c46
1 files changed, 46 insertions, 0 deletions
diff --git a/src/device/i2c.c b/src/device/i2c.c
new file mode 100644
index 0000000000..53bfdf0c94
--- /dev/null
+++ b/src/device/i2c.c
@@ -0,0 +1,46 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 MediaTek Inc.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#include <device/i2c.h>
+
+int i2c_read_field(unsigned bus, uint8_t chip, uint8_t reg, uint8_t *data,
+ uint8_t mask, uint8_t shift)
+{
+ int ret;
+ uint8_t buf = 0;
+
+ ret = i2c_readb(bus, chip, reg, &buf);
+
+ buf &= (mask << shift);
+ *data = (buf >> shift);
+
+ return ret;
+}
+
+int i2c_write_field(unsigned bus, uint8_t chip, uint8_t reg, uint8_t data,
+ uint8_t mask, uint8_t shift)
+{
+ int ret;
+ uint8_t buf = 0;
+
+ ret = i2c_readb(bus, chip, reg, &buf);
+
+ buf &= ~(mask << shift);
+ buf |= (data << shift);
+
+ ret |= i2c_writeb(bus, chip, reg, buf);
+
+ return ret;
+}