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tegra124: set MOT bit for I2C-over-AUX

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According to DP version 1.2a, The MOT (Middle-of-Transaction) bit
must be set when the I2C transaction does not stop with the current
AUX transaction.
Thus the correct steps for an I2C read shall be:
1. I2C command write with MOT set to 1
2. I2C command read to the same address with MOT set to 0

BUG=chrome-os-partner:27679
TEST=EDID data read from LP140WH8 panel is correct while it's a
repeated pattern of the first 16 bytes without this CL
BRANCH=none

Change-Id: I0526beffb8852fbbe0eb5bb80e370261617a59b8
Signed-off-by: Ken Chang <kenc@nvidia.com>
Reviewed-on: https://chromium-review.googlesource.com/194915
Reviewed-by: Tom Warren <twarren@nvidia.com>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
This commit is contained in:
Ken Chang 2014-04-15 17:00:17 +08:00 • committed by chrome-internal-fetch
commit 466ab0e007
1 changed files with 1 additions and 1 deletions
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2
src/soc/nvidia/tegra124/dp.c
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@ -337,7 +337,7 @@ int tegra_dc_i2c_aux_read(struct tegra_dc_dp_data *dp, u32 i2c_addr,
u32 len = 1;
ret = tegra_dc_dpaux_write_chunk(
dp, DPAUX_DP_AUXCTL_CMD_I2CWR, i2c_addr,
dp, DPAUX_DP_AUXCTL_CMD_MOTWR, i2c_addr,
&addr, &len, aux_stat);
if (ret) {
printk(BIOS_ERR, "%s: error sending address to read.\n",