On Wed, Oct 24, 2012 at 01:38:55PM +0200, Matthias Brugger wrote:
> This patch encapsulates the variables used by the default debounce
> filter in a struct. The values are allocated only if the debounce filter
> is used by the platform.
>
> Signed-off-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> ---
> drivers/input/touchscreen/ads7846.c | 42 ++++++++++++++++++++++-------------
> 1 file changed, 27 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
> index f02028e..9e61a4b 100644
> --- a/drivers/input/touchscreen/ads7846.c
> +++ b/drivers/input/touchscreen/ads7846.c
> @@ -90,6 +90,15 @@ struct ads7846_packet {
> u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
> };
>
> +struct ads7846_filterd {
> + int read_cnt;
> + int read_rep;
> + int last_read;
> + u16 debounce_max;
> + u16 debounce_tol;
> + u16 debounce_rep;
> +};
> +
> struct ads7846 {
> struct input_dev *input;
> char phys[32];
> @@ -121,14 +130,6 @@ struct ads7846 {
>
> bool pendown;
>
> - int read_cnt;
> - int read_rep;
> - int last_read;
> -
> - u16 debounce_max;
> - u16 debounce_tol;
> - u16 debounce_rep;
> -
> u16 penirq_recheck_delay_usecs;
>
> struct mutex lock;
> @@ -643,9 +644,14 @@ static void null_wait_for_sync(void)
> {
> }
>
> +static void ads7864_filter_cleanup(void *data)
> +{
> + kfree(data);
> +}
> +
> static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
> {
> - struct ads7846 *ts = ads;
> + struct ads7846_filterd *ts = (struct ads7846_filterd*) ads;
>
> if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
> /* Start over collecting consistent readings. */
> @@ -1261,13 +1267,19 @@ static int __devinit ads7846_probe(struct spi_device *spi)
> ts->filter = pdata->filter;
> ts->filter_cleanup = pdata->filter_cleanup;
> } else if (pdata->debounce_max) {
> - ts->debounce_max = pdata->debounce_max;
> - if (ts->debounce_max < 2)
> - ts->debounce_max = 2;
> - ts->debounce_tol = pdata->debounce_tol;
> - ts->debounce_rep = pdata->debounce_rep;
> + struct ads7846_filterd *fdata = kmalloc(sizeof(struct ads7846_filterd), GFP_KERNEL);
> + if (!fdata) {
> + err = -ENOMEM;
> + goto err_free_mem;
> + }
> + fdata->debounce_max = pdata->debounce_max;
> + if (fdata->debounce_max < 2)
> + fdata->debounce_max = 2;
> + fdata->debounce_tol = pdata->debounce_tol;
> + fdata->debounce_rep = pdata->debounce_rep;
> ts->filter = ads7846_debounce_filter;
> - ts->filter_data = ts;
> + ts->filter_cleanup = ads7864_filter_cleanup;
> + ts->filter_data = fdata;
So you are maybe saving 18 bytes if data in ads7846 at the expense
of more code... Not really see the great benefit. Maybe just embed
your new ads7846_debounce_data structure in ads7846 to provide logical
separation?
--
Dmitry
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