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authorJitao Shi <jitao.shi@mediatek.com>2016-02-01 17:33:49 +0800
committerPatrick Georgi <pgeorgi@google.com>2016-03-12 09:11:43 +0100
commit5ffb6887c27d86215c5ffa603131ff9b1f0929ae (patch)
tree05b1e7c548145987e318767bab9ffeaa42a9f1b4
parent358f66a44266afd5b6ee9cfa3bcbe45b0dd3a799 (diff)
downloadcoreboot-5ffb6887c27d86215c5ffa603131ff9b1f0929ae.tar.xz
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>
-rw-r--r--src/include/device/i2c.h22
1 files changed, 22 insertions, 0 deletions
diff --git a/src/include/device/i2c.h b/src/include/device/i2c.h
index 78817bb300..8e59ba7c21 100644
--- a/src/include/device/i2c.h
+++ b/src/include/device/i2c.h
@@ -88,6 +88,28 @@ static inline int i2c_write_raw(unsigned bus, uint8_t chip, uint8_t *data,
}
/**
+ * 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 = &reg;
+ 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]