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| author | Vic (Chun-Ju) Yang <victoryang@chromium.org> | 2014-01-09 15:01:23 +0800 |
|---|---|---|
| committer | chrome-internal-fetch <chrome-internal-fetch@google.com> | 2014-01-09 13:58:39 +0000 |
| commit | aea8b2d79860ee0cf1117455070c6af45892309c (patch) | |
| tree | f423a41aadc93f7025f56bb8943565d8494f2ca3 | |
| parent | 9867f8379a09d60b3df8c62c269627714e97b2ac (diff) | |
| download | chrome-ec-aea8b2d79860ee0cf1117455070c6af45892309c.tar.gz | |
Enable internal pull-up for MEC1322 EVB I2C bus
The external pull-up resistors are too weak, and cause slow-down on I2C
speed. Let's enable internal pull-up to compensate this.
BUG=chrome-os-partner:24389
TEST=Measure I2C speed with scope, and see better slew rate.
BRANCH=None
Change-Id: Iefb5fca3c88250bbd8cad29d7998d590a7cc7c35
Signed-off-by: Vic (Chun-Ju) Yang <victoryang@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/181999
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
| -rw-r--r-- | board/mec1322_evb/board.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/board/mec1322_evb/board.c b/board/mec1322_evb/board.c index 5d7dd42bb9..f363baf788 100644 --- a/board/mec1322_evb/board.c +++ b/board/mec1322_evb/board.c @@ -35,7 +35,11 @@ const struct gpio_alt_func gpio_alt_funcs[] = { {GPIO_PORT(16), 0x24, 1, MODULE_UART}, /* UART0 */ {GPIO_PORT(3), (1 << 4), 3, MODULE_PWM_FAN}, {GPIO_PORT(14), (1 << 0), 3, MODULE_PWM_FAN}, - {GPIO_PORT(1), 0x60, 2, MODULE_I2C}, /* I2C0 */ + /* + * I2C0: External pull-up resistors on EVB are too weak. Let's + * also enable internal pull-up here. + */ + {GPIO_PORT(1), 0x60, 2, MODULE_I2C, GPIO_PULL_UP}, {GPIO_PORT(0), 0xfe, 3, MODULE_KEYBOARD_SCAN, GPIO_KB_OUTPUT}, {GPIO_PORT(1), 0x03, 3, MODULE_KEYBOARD_SCAN, GPIO_KB_OUTPUT}, {GPIO_PORT(3), 0x04, 3, MODULE_KEYBOARD_SCAN, GPIO_KB_INPUT}, |