Re: [PATCH V2 1/2] Input: of_keymap: Introduce matrix_keypad_of_build_keymap()

[Stephen Warren <swarren@wwwdotorg.org>]

On 03/26/2012 11:38 PM, Viresh Kumar wrote:
> We don't need to allocate memory for keymap in matrix_keyboard_of_fill_keymap(),
> as this would only be used by matrix_keyboard_of_free_keymap(). Instead create
> another routine matrix_keypad_of_build_keymap() which reads directly the
> property from struct device_node and builds keymap.
> 
> With this eariler routines matrix_keyboard_of_fill_keymap() and
> matrix_keyboard_of_free_keymap() go away.
> 
> This patch also fixes tegra driver according to these changes.

> diff --git a/drivers/input/keyboard/tegra-kbc.c b/drivers/input/keyboard/tegra-kbc.c
...
>  static int __devinit tegra_kbc_probe(struct platform_device *pdev)
...
> +	if (pdev->dev.of_node) {
> +		/* FIXME: Add handling of linux,fn-keymap here */
> +		err = matrix_keypad_of_build_keymap(&pdev->dev, KBC_ROW_SHIFT,
> +				input_dev->keycode, input_dev->keybit,
> +				"linux,keymap");

Where do input_dev->keycode/keybit get allocated? As far as I can tell,
matrix_keypad_of_build_keymap() just writes to those and assumes they're
already allocated.

> diff --git a/drivers/input/of_keymap.c b/drivers/input/of_keymap.c
...
> +int matrix_keypad_of_build_keymap(struct device *dev, unsigned int row_shift,
...
> +		keymap[MATRIX_SCAN_CODE(row, col, row_shift)] = code;
> +		__set_bit(code, keybit);

How bit are keymap and keybit? I think we need range-checking here to
make sure that row/col/row_shift/code are valid and in-range.