[PATCH] Input: marix-keymap - automatically allocate memory for keymap

[PATCH] Input: marix-keymap - automatically allocate memory for keymap

[Dmitry Torokhov]

In device tree enabled setups requiring preallocated memory for storing keymap
is quite often awkward, so let's provide an option of allocating it directly
in matrix_keypad_build_keymap().

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/matrix-keymap.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/input/matrix-keymap.c b/drivers/input/matrix-keymap.c
index 443ad64b..da04f13 100644
--- a/drivers/input/matrix-keymap.c
+++ b/drivers/input/matrix-keymap.c
@@ -122,6 +122,11 @@ static int matrix_keypad_parse_of_keymap(const char *propname,
  * it will attempt load the keymap from property specified by @keymap_name
  * argument (or "linux,keymap" if @keymap_name is %NULL).
  *
+ * If @keymap is %NULL the function will automatically allocate managed
+ * block of memory to store the keymap. This memory will be associated with
+ * the parent device and automatically freed when device unbinds from the
+ * driver.
+ *
  * Callers are expected to set up input_dev->dev.parent before calling this
  * function.
  */
@@ -132,12 +137,27 @@ int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data,
 			       struct input_dev *input_dev)
 {
 	unsigned int row_shift = get_count_order(cols);
+	size_t max_keys = rows << row_shift;
 	int i;
 	int error;
 
+	if (WARN_ON(!input_dev->dev.parent))
+		return -EINVAL;
+
+	if (!keymap) {
+		keymap = devm_kzalloc(input_dev->dev.parent,
+				      max_keys * sizeof(*keymap),
+				      GFP_KERNEL);
+		if (!keymap) {
+			dev_err(input_dev->dev.parent,
+				"Unable to allocate memory for keymap");
+			return -ENOMEM;
+		}
+	}
+
 	input_dev->keycode = keymap;
 	input_dev->keycodesize = sizeof(*keymap);
-	input_dev->keycodemax = rows << row_shift;
+	input_dev->keycodemax = max_keys;
 
 	__set_bit(EV_KEY, input_dev->evbit);
 
-- 
1.7.11.7


-- 
Dmitry

Re: [PATCH] Input: marix-keymap - automatically allocate memory for keymap

[Alban Bedel]

On Thu, 8 Nov 2012 08:45:21 -0800
Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:

> In device tree enabled setups requiring preallocated memory for storing keymap
> is quite often awkward, so let's provide an option of allocating it directly
> in matrix_keypad_build_keymap().
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---
>  drivers/input/matrix-keymap.c | 22 +++++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/input/matrix-keymap.c b/drivers/input/matrix-keymap.c
> index 443ad64b..da04f13 100644
> --- a/drivers/input/matrix-keymap.c
> +++ b/drivers/input/matrix-keymap.c
> @@ -122,6 +122,11 @@ static int matrix_keypad_parse_of_keymap(const char *propname,
>   * it will attempt load the keymap from property specified by @keymap_name
>   * argument (or "linux,keymap" if @keymap_name is %NULL).
>   *
> + * If @keymap is %NULL the function will automatically allocate managed
> + * block of memory to store the keymap. This memory will be associated with
> + * the parent device and automatically freed when device unbinds from the
> + * driver.
> + *
>   * Callers are expected to set up input_dev->dev.parent before calling this
>   * function.
>   */
> @@ -132,12 +137,27 @@ int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data,
>  			       struct input_dev *input_dev)
>  {
>  	unsigned int row_shift = get_count_order(cols);
> +	size_t max_keys = rows << row_shift;
>  	int i;
>  	int error;
>  
> +	if (WARN_ON(!input_dev->dev.parent))
> +		return -EINVAL;
> +
> +	if (!keymap) {
> +		keymap = devm_kzalloc(input_dev->dev.parent,
> +				      max_keys * sizeof(*keymap),
> +				      GFP_KERNEL);

In my tree GFP_KERNEL isn't defined at that point. Is an include
missing in this patch or is my tree (3.6+some next cherry picks)
missing a commit?

> +		if (!keymap) {
> +			dev_err(input_dev->dev.parent,
> +				"Unable to allocate memory for keymap");
> +			return -ENOMEM;
> +		}
> +	}
> +
>  	input_dev->keycode = keymap;
>  	input_dev->keycodesize = sizeof(*keymap);
> -	input_dev->keycodemax = rows << row_shift;
> +	input_dev->keycodemax = max_keys;
>  
>  	__set_bit(EV_KEY, input_dev->evbit);
>  

Otherwise that look good to me.

Alban

Re: [PATCH] Input: marix-keymap - automatically allocate memory for keymap

[Dmitry Torokhov]

Hi Alban,

On Wed, Nov 14, 2012 at 10:40:59AM +0100, Alban Bedel wrote:
> On Thu, 8 Nov 2012 08:45:21 -0800
> Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> 
> > +	if (!keymap) {
> > +		keymap = devm_kzalloc(input_dev->dev.parent,
> > +				      max_keys * sizeof(*keymap),
> > +				      GFP_KERNEL);
> 
> In my tree GFP_KERNEL isn't defined at that point. Is an include
> missing in this patch or is my tree (3.6+some next cherry picks)
> missing a commit?

No, I apparetnly had an older tree when I created a patch, i have since
added include/linux/gfp.h

> 
> > +		if (!keymap) {
> > +			dev_err(input_dev->dev.parent,
> > +				"Unable to allocate memory for keymap");
> > +			return -ENOMEM;
> > +		}
> > +	}
> > +
> >  	input_dev->keycode = keymap;
> >  	input_dev->keycodesize = sizeof(*keymap);
> > -	input_dev->keycodemax = rows << row_shift;
> > +	input_dev->keycodemax = max_keys;
> >  
> >  	__set_bit(EV_KEY, input_dev->evbit);
> >  
> 
> Otherwise that look good to me.

Great, I am putting you down as reviewed-by then.

Thanks.

-- 
Dmitry