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authorYidi Lin <yidi.lin@mediatek.com>2016-03-15 14:38:44 +0800
committerMartin Roth <martinroth@google.com>2016-03-21 23:10:55 +0100
commitd33ebd13741b7473e93a1a6780edbb1e2dca8258 (patch)
tree66fd6e199ad63397f4d2c3fbb16debb088231c91 /src/device/i2c.c
parentf7d4f73053f0c26bfe411a9f3ef86f98389538b5 (diff)
downloadcoreboot-d33ebd13741b7473e93a1a6780edbb1e2dca8258.tar.xz
device: Add i2c read/write register field API
i2c_read_field() - read the value from the specific register field i2c_write_field() - write the value to the specific register field BRANCH=none BUG=none TEST=none Change-Id: I2098715b4583c1936c93b3ff45ec330910964304 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 0817fc76d07491b39c066f1393a6435f0831b50c Original-Change-Id: I92c187a89d10cfcecf3dfd9291e0bc015459c393 Original-Signed-off-by: Yidi Lin <yidi.lin@mediatek.com> Original-Reviewed-on: https://chromium-review.googlesource.com/332712 Original-Reviewed-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://review.coreboot.org/14105 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org> Reviewed-by: Martin Roth <martinroth@google.com>
Diffstat (limited to 'src/device/i2c.c')
-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;
+}