diff options
| author | Randall Spangler <rspangler@chromium.org> | 2012-06-06 12:29:43 -0700 |
|---|---|---|
| committer | Gerrit <chrome-bot@google.com> | 2012-06-07 09:59:54 -0700 |
| commit | c736b2874c5144c752491c5bfe7025a91034767a (patch) | |
| tree | 2d9a97cc0b230a5a4dad087a32230f04cc51ebf9 | |
| parent | 12eecc012ba5c0c37beafa03fe70f97fedf3e726 (diff) | |
| download | chrome-ec-c736b2874c5144c752491c5bfe7025a91034767a.tar.gz | |
Switch keyboard outputs to open-drain
BUG=chrome-os-partner:10209
TEST=boot system and type on console; should still work
Change-Id: I9f89420acd59947baee445fc2a655857809f8fb9
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/24636
| -rw-r--r-- | chip/lm4/keyboard_scan.c | 34 |
1 files changed, 13 insertions, 21 deletions
diff --git a/chip/lm4/keyboard_scan.c b/chip/lm4/keyboard_scan.c index ae7223f69f..0d2909e53a 100644 --- a/chip/lm4/keyboard_scan.c +++ b/chip/lm4/keyboard_scan.c @@ -87,25 +87,20 @@ static void select_column(int col) { if (col == COLUMN_TRI_STATE_ALL || !enable_scanning) { /* Tri-state all outputs */ - LM4_GPIO_DIR(LM4_GPIO_P) = 0; - LM4_GPIO_DIR(LM4_GPIO_Q) &= ~0x1f; + LM4_GPIO_DATA(LM4_GPIO_P, 0xff) = 0xff; + LM4_GPIO_DATA(LM4_GPIO_Q, 0x1f) = 0x1f; } else if (col == COLUMN_ASSERT_ALL) { /* Assert all outputs */ - LM4_GPIO_DIR(LM4_GPIO_P) = 0xff; - LM4_GPIO_DIR(LM4_GPIO_Q) |= 0x1f; LM4_GPIO_DATA(LM4_GPIO_P, 0xff) = 0; LM4_GPIO_DATA(LM4_GPIO_Q, 0x1f) = 0; } else { /* Assert a single output */ - LM4_GPIO_DIR(LM4_GPIO_P) = 0; - LM4_GPIO_DIR(LM4_GPIO_Q) &= ~0x1f; - if (col < 8) { - LM4_GPIO_DIR(LM4_GPIO_P) |= 1 << col; + LM4_GPIO_DATA(LM4_GPIO_P, 0xff) = 0xff; + LM4_GPIO_DATA(LM4_GPIO_Q, 0x1f) = 0x1f; + if (col < 8) LM4_GPIO_DATA(LM4_GPIO_P, 1 << col) = 0; - } else { - LM4_GPIO_DIR(LM4_GPIO_Q) |= 1 << (col - 8); + else LM4_GPIO_DATA(LM4_GPIO_Q, 1 << (col - 8)) = 0; - } } } @@ -278,19 +273,16 @@ static int check_boot_key(int index, int mask) int keyboard_scan_init(void) { - volatile uint32_t scratch __attribute__((unused)); - - /* Enable clock to GPIO modules N,P,Q */ - /* TODO: gpio_pre_init() enables all the GPIO modules, so can remove - * this entirely. */ - LM4_SYSTEM_RCGCGPIO |= 0x7000; - scratch = LM4_SYSTEM_RCGCGPIO; - - /* Clear GPIOAFSEL and enable digital function for rows */ + /* Set column outputs as open-drain; we either pull them low or let + * them float high. */ LM4_GPIO_AFSEL(LM4_GPIO_P) = 0; /* KSO[7:0] */ - LM4_GPIO_DEN(LM4_GPIO_P) = 0xff; LM4_GPIO_AFSEL(LM4_GPIO_Q) &= ~0x1f; /* KSO[12:8] */ + LM4_GPIO_DEN(LM4_GPIO_P) = 0xff; LM4_GPIO_DEN(LM4_GPIO_Q) |= 0x1f; + LM4_GPIO_DIR(LM4_GPIO_P) = 0xff; + LM4_GPIO_DIR(LM4_GPIO_Q) |= 0x1f; + LM4_GPIO_ODR(LM4_GPIO_P) = 0xff; + LM4_GPIO_ODR(LM4_GPIO_Q) |= 0x1f; /* Set row inputs with pull-up */ LM4_GPIO_AFSEL(KB_SCAN_ROW_GPIO) &= 0xff; |