From 8f75bc3377fa6f2af16383cc8346abd81909353f Mon Sep 17 00:00:00 2001 From: Damien Riegel Date: Thu, 19 Oct 2017 15:34:55 -0700 Subject: [PATCH] Input: tca8418 - enable interrupt after it has been requested Currently, enabling keypad interrupts is one of the first operations done on the keypad, even before the interrupt is requested, so there is a small time window where the keypad can fire interrupts but the driver is not yet ready to handle them. It's fine for level interrupts because they will be handled anyway, but not so much for edge ones. This commit modifies and moves the function in charge of configuring the keypad. Enabling interrupts is now the last thing done on the keypad, and after the interrupt has been requested by the driver. Writing to the config register was also used to determine if the device was indeed present on the bus or not, this has been replaced by reading the lock/event count register to keep the same functionality. Signed-off-by: Damien Riegel Signed-off-by: Dmitry Torokhov --- drivers/input/keyboard/tca8418_keypad.c | 29 +++++++++++++++---------- 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/drivers/input/keyboard/tca8418_keypad.c b/drivers/input/keyboard/tca8418_keypad.c index e37e335e406f..6da607d3b811 100644 --- a/drivers/input/keyboard/tca8418_keypad.c +++ b/drivers/input/keyboard/tca8418_keypad.c @@ -234,14 +234,7 @@ static irqreturn_t tca8418_irq_handler(int irq, void *dev_id) static int tca8418_configure(struct tca8418_keypad *keypad_data, u32 rows, u32 cols) { - int reg, error; - - /* Write config register, if this fails assume device not present */ - error = tca8418_write_byte(keypad_data, REG_CFG, - CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN); - if (error < 0) - return -ENODEV; - + int reg, error = 0; /* Assemble a mask for row and column registers */ reg = ~(~0 << rows); @@ -257,6 +250,12 @@ static int tca8418_configure(struct tca8418_keypad *keypad_data, error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8); error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16); + if (error) + return error; + + error = tca8418_write_byte(keypad_data, REG_CFG, + CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN); + return error; } @@ -268,6 +267,7 @@ static int tca8418_keypad_probe(struct i2c_client *client, struct input_dev *input; u32 rows = 0, cols = 0; int error, row_shift, max_keys; + u8 reg; /* Check i2c driver capabilities */ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) { @@ -301,10 +301,10 @@ static int tca8418_keypad_probe(struct i2c_client *client, keypad_data->client = client; keypad_data->row_shift = row_shift; - /* Initialize the chip or fail if chip isn't present */ - error = tca8418_configure(keypad_data, rows, cols); - if (error < 0) - return error; + /* Read key lock register, if this fails assume device not present */ + error = tca8418_read_byte(keypad_data, REG_KEY_LCK_EC, ®); + if (error) + return -ENODEV; /* Configure input device */ input = devm_input_allocate_device(dev); @@ -340,6 +340,11 @@ static int tca8418_keypad_probe(struct i2c_client *client, return error; } + /* Initialize the chip */ + error = tca8418_configure(keypad_data, rows, cols); + if (error < 0) + return error; + error = input_register_device(input); if (error) { dev_err(dev, "Unable to register input device, error: %d\n", -- 2.30.2