From 7c12a5b19e13ee78c3acb759f264df87ad984ffa Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Mon, 15 Dec 2014 22:23:40 -0800 Subject: Input: stmpe - bias keypad columns properly All keypad column pins used as inputs should be pulled up on the STMPE24xx, but this is not done by the current driver. Add some logic that will do this properly. The STMPE1601 also has a keypad controller, but explicitly does *NOT* require you to set up any pull-ups. Signed-off-by: Linus Walleij Signed-off-by: Dmitry Torokhov --- drivers/input/keyboard/stmpe-keypad.c | 37 +++++++++++++++++++++++++++++++++-- 1 file changed, 35 insertions(+), 2 deletions(-) (limited to 'drivers/input') diff --git a/drivers/input/keyboard/stmpe-keypad.c b/drivers/input/keyboard/stmpe-keypad.c index 8d1e7af3c5b1..64514e64d557 100644 --- a/drivers/input/keyboard/stmpe-keypad.c +++ b/drivers/input/keyboard/stmpe-keypad.c @@ -52,6 +52,7 @@ * struct stmpe_keypad_variant - model-specific attributes * @auto_increment: whether the KPC_DATA_BYTE register address * auto-increments on multiple read + * @set_pullup: whether the pins need to have their pull-ups set * @num_data: number of data bytes * @num_normal_data: number of normal keys' data bytes * @max_cols: maximum number of columns supported @@ -61,6 +62,7 @@ */ struct stmpe_keypad_variant { bool auto_increment; + bool set_pullup; int num_data; int num_normal_data; int max_cols; @@ -81,6 +83,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = { }, [STMPE2401] = { .auto_increment = false, + .set_pullup = true, .num_data = 3, .num_normal_data = 2, .max_cols = 8, @@ -90,6 +93,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = { }, [STMPE2403] = { .auto_increment = true, + .set_pullup = true, .num_data = 5, .num_normal_data = 3, .max_cols = 8, @@ -185,7 +189,10 @@ static int stmpe_keypad_altfunc_init(struct stmpe_keypad *keypad) unsigned int col_gpios = variant->col_gpios; unsigned int row_gpios = variant->row_gpios; struct stmpe *stmpe = keypad->stmpe; + u8 pureg = stmpe->regs[STMPE_IDX_GPPUR_LSB]; unsigned int pins = 0; + unsigned int pu_pins = 0; + int ret; int i; /* @@ -202,8 +209,10 @@ static int stmpe_keypad_altfunc_init(struct stmpe_keypad *keypad) for (i = 0; i < variant->max_cols; i++) { int num = __ffs(col_gpios); - if (keypad->cols & (1 << i)) + if (keypad->cols & (1 << i)) { pins |= 1 << num; + pu_pins |= 1 << num; + } col_gpios &= ~(1 << num); } @@ -217,7 +226,31 @@ static int stmpe_keypad_altfunc_init(struct stmpe_keypad *keypad) row_gpios &= ~(1 << num); } - return stmpe_set_altfunc(stmpe, pins, STMPE_BLOCK_KEYPAD); + ret = stmpe_set_altfunc(stmpe, pins, STMPE_BLOCK_KEYPAD); + if (ret) + return ret; + + /* + * On STMPE24xx, set pin bias to pull-up on all keypad input + * pins (columns), this incidentally happen to be maximum 8 pins + * and placed at GPIO0-7 so only the LSB of the pull up register + * ever needs to be written. + */ + if (variant->set_pullup) { + u8 val; + + ret = stmpe_reg_read(stmpe, pureg); + if (ret) + return ret; + + /* Do not touch unused pins, may be used for GPIO */ + val = ret & ~pu_pins; + val |= pu_pins; + + ret = stmpe_reg_write(stmpe, pureg, val); + } + + return 0; } static int stmpe_keypad_chip_init(struct stmpe_keypad *keypad) -- cgit v1.2.3