Input: tca6416-keypad - add support for tca6408a

Support 8-bit tca6408a I/O expander as a keypad.
Signed-off-by: Tony SIM <chinyeow.sim.xt@renesas.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/keyboard/Kconfig

@@ -180,20 +180,22 @@ config KEYBOARD_GPIO
 	  module will be called gpio_keys.
 
 config KEYBOARD_TCA6416
-	tristate "TCA6416 Keypad Support"
+	tristate "TCA6416/TCA6408A Keypad Support"
 	depends on I2C
 	help
 	  This driver implements basic keypad functionality
-	  for keys connected through TCA6416 IO expander
+	  for keys connected through TCA6416/TCA6408A IO expanders.
 
 	  Say Y here if your device has keys connected to
-	  TCA6416 IO expander. Your board-specific setup logic
+	  TCA6416/TCA6408A IO expander. Your board-specific setup logic
 	  must also provide pin-mask details(of which TCA6416 pins
 	  are used for keypad).
 
-	  If enabled the complete TCA6416 device will be managed through
+	  If enabled the entire TCA6416 device will be managed through
 	  this driver.
 
+	  To compile this driver as a module, choose M here: the
+	  module will be called tca6416_keypad.
 
 config KEYBOARD_MATRIX
 	tristate "GPIO driven matrix keypad support"

drivers/input/keyboard/tca6416-keypad.c

@@ -29,6 +29,7 @@
 
 static const struct i2c_device_id tca6416_id[] = {
 	{ "tca6416-keys", 16, },
+	{ "tca6408-keys", 8, },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, tca6416_id);
@@ -46,8 +47,9 @@ struct tca6416_keypad_chip {
 	struct i2c_client *client;
 	struct input_dev *input;
 	struct delayed_work dwork;
-	u16 pinmask;
+	int io_size;
 	int irqnum;
+	u16 pinmask;
 	bool use_polling;
 	struct tca6416_button buttons[0];
 };
@@ -56,7 +58,9 @@ static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg, u16 val)
 {
 	int error;
 
-	error = i2c_smbus_write_word_data(chip->client, reg << 1, val);
+	error = chip->io_size > 8 ?
+		i2c_smbus_write_word_data(chip->client, reg << 1, val) :
+		i2c_smbus_write_byte_data(chip->client, reg, val);
 	if (error < 0) {
 		dev_err(&chip->client->dev,
 			"%s failed, reg: %d, val: %d, error: %d\n",
@@ -71,7 +75,9 @@ static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg, u16 *val)
 {
 	int retval;
 
-	retval = i2c_smbus_read_word_data(chip->client, reg << 1);
+	retval = chip->io_size > 8 ?
+		 i2c_smbus_read_word_data(chip->client, reg << 1) :
+		 i2c_smbus_read_byte_data(chip->client, reg);
 	if (retval < 0) {
 		dev_err(&chip->client->dev, "%s failed, reg: %d, error: %d\n",
 			__func__, reg, retval);
@@ -224,6 +230,7 @@ static int __devinit tca6416_keypad_probe(struct i2c_client *client,
 
 	chip->client = client;
 	chip->input = input;
+	chip->io_size = id->driver_data;
 	chip->pinmask = pdata->pinmask;
 	chip->use_polling = pdata->use_polling;