device/i2c: Add i2c_read_bytes() API
Add multi-bytes read support.
BRANCH=none
BUG=none
TEST=saw edid log and dev screen
Change-Id: I106be98e751e2a3b998ccaedb28f71f3c6e18994
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 94ee0b834947e8d971943aa24e61a9353c7b7306
Original-Change-Id: Iac5fe497da92b7d09383e0d6a04d98709aea5b20
Original-Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/325211
Original-Commit-Ready: Yidi Lin <yidi.lin@mediatek.com>
Original-Tested-by: Yidi Lin <yidi.lin@mediatek.com>
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/13978
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/include/device/i2c.h b/src/include/device/i2c.h
index 78817bb..8e59ba7 100644
--- a/src/include/device/i2c.h
+++ b/src/include/device/i2c.h
@@ -88,6 +88,28 @@
}
/**
+ * Read multi-bytes with two segments in one frame
+ *
+ * [start][slave addr][w][register addr][start][slave addr][r][data...][stop]
+ */
+static inline int i2c_read_bytes(unsigned bus, uint8_t chip, uint8_t reg,
+ uint8_t *data, int len)
+{
+ struct i2c_seg seg[2];
+
+ seg[0].read = 0;
+ seg[0].chip = chip;
+ seg[0].buf = ®
+ seg[0].len = 1;
+ seg[1].read = 1;
+ seg[1].chip = chip;
+ seg[1].buf = data;
+ seg[1].len = len;
+
+ return i2c_transfer(bus, seg, ARRAY_SIZE(seg));
+}
+
+/**
* Read a byte with two segments in one frame
*
* [start][slave addr][w][register addr][start][slave addr][r][data][stop]