input: Allow key ghosting filter to be disabled

Some keyboards will not need a key ghosting filter, so make this feature
optional.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/input/key_matrix.c b/drivers/input/key_matrix.c
index c08caa68295b8230c83f6065098535a8ac809523..287bf0dcc9ca15a1095bbed05a31267b4c875a4f 100644 (file)
--- a/drivers/input/key_matrix.c
+++ b/drivers/input/key_matrix.c
@@ -46,6 +46,9 @@ static int has_ghosting(struct key_matrix *config, struct key_matrix_key *keys,
        int key_in_same_col = 0, key_in_same_row = 0;
        int i, j;
 
+       if (!config->ghost_filter || valid < 3)
+               return 0;
+
        for (i = 0; i < valid; i++) {
                /*
                 * Find 2 keys such that one key is in the same row
@@ -92,7 +95,7 @@ int key_matrix_decode(struct key_matrix *config, struct key_matrix_key keys[],
        }
 
        /* For a ghost key config, ignore the keypresses for this iteration. */
-       if (valid >= 3 && has_ghosting(config, keys, valid)) {
+       if (has_ghosting(config, keys, valid)) {
                valid = 0;
                debug("    ghosting detected!\n");
        }
@@ -200,12 +203,14 @@ int key_matrix_decode_fdt(struct key_matrix *config, const void *blob,
        return 0;
 }
 
-int key_matrix_init(struct key_matrix *config, int rows, int cols)
+int key_matrix_init(struct key_matrix *config, int rows, int cols,
+                   int ghost_filter)
 {
        memset(config, '\0', sizeof(*config));
        config->num_rows = rows;
        config->num_cols = cols;
        config->key_count = rows * cols;
+       config->ghost_filter = ghost_filter;
        assert(config->key_count > 0);
 
        return 0;

diff --git a/drivers/input/tegra-kbc.c b/drivers/input/tegra-kbc.c
index 9a309421f04f91a01e3f10e8a9b75d1d72024142..6f1cfd81559c4c0a461bf1d9c69628fd5054c1ca 100644 (file)
--- a/drivers/input/tegra-kbc.c
+++ b/drivers/input/tegra-kbc.c
@@ -325,7 +325,7 @@ static int init_tegra_keyboard(void)
                        KBC_REPEAT_RATE_MS);
 
        /* Decode the keyboard matrix information (16 rows, 8 columns) */
-       if (key_matrix_init(&config.matrix, 16, 8)) {
+       if (key_matrix_init(&config.matrix, 16, 8, 1)) {
                debug("%s: Could not init key matrix\n", __func__);
                return -1;
        }

diff --git a/include/key_matrix.h b/include/key_matrix.h
index f41331407dc63b795636eb7b293f0c5497320df5..962971650ea10684cac49b6a5b84e8620e77b174 100644 (file)
--- a/include/key_matrix.h
+++ b/include/key_matrix.h
@@ -40,6 +40,7 @@ struct key_matrix {
        const u8 *plain_keycode;        /* key code for each row / column */
        const u8 *fn_keycode;           /* ...when Fn held down */
        int fn_pos;                     /* position of Fn key in key (or -1) */
+       int ghost_filter;               /* non-zero to enable ghost filter */
 };
 
 /* Information about a particular key (row, column pair) in the matrix */
@@ -92,8 +93,10 @@ int key_matrix_decode_fdt(struct key_matrix *config, const void *blob,
  * @param config       Keyboard matrix config
  * @param rows         Number of rows in key matrix
  * @param cols         Number of columns in key matrix
+ * @param ghost_filter Non-zero to enable ghost filtering
  * @return 0 if ok, -1 on error
  */
-int key_matrix_init(struct key_matrix *config, int rows, int cols);
+int key_matrix_init(struct key_matrix *config, int rows, int cols,
+                   int ghost_filter);
 
 #endif