1 files changed, 38 insertions, 22 deletions

diff --git a/drivers/input/keyboard/tegra-kbc.c b/drivers/input/keyboard/tegra-kbc.c
index 99ce9032d08c..2b3b73ec6689 100644
--- a/drivers/input/keyboard/tegra-kbc.c
+++ b/drivers/input/keyboard/tegra-kbc.c
@@ -66,12 +66,11 @@ struct tegra_kbc {
         void __iomem *mmio;
         struct input_dev *idev;
         unsigned int irq;
-        unsigned int wake_enable_rows;
-        unsigned int wake_enable_cols;
         spinlock_t lock;
         unsigned int repoll_dly;
         unsigned long cp_dly_jiffies;
         bool use_fn_map;
+        bool use_ghost_filter;
         const struct tegra_kbc_platform_data *pdata;
         unsigned short keycode[KBC_MAX_KEY * 2];
         unsigned short current_keys[KBC_MAX_KPENT];
@@ -260,6 +259,8 @@ static void tegra_kbc_report_keys(struct tegra_kbc *kbc)
         unsigned int num_down = 0;
         unsigned long flags;
         bool fn_keypress = false;
+        bool key_in_same_row = false;
+        bool key_in_same_col = false;
 
         spin_lock_irqsave(&kbc->lock, flags);
         for (i = 0; i < KBC_MAX_KPENT; i++) {
@@ -285,6 +286,34 @@ static void tegra_kbc_report_keys(struct tegra_kbc *kbc)
         }
 
         /*
+         * Matrix keyboard designs are prone to keyboard ghosting.
+         * Ghosting occurs if there are 3 keys such that -
+         * any 2 of the 3 keys share a row, and any 2 of them share a column.
+         * If so ignore the key presses for this iteration.
+         */
+        if ((kbc->use_ghost_filter) && (num_down >= 3)) {
+                for (i = 0; i < num_down; i++) {
+                        unsigned int j;
+                        u8 curr_col = scancodes[i] & 0x07;
+                        u8 curr_row = scancodes[i] >> KBC_ROW_SHIFT;
+
+                        /*
+                         * Find 2 keys such that one key is in the same row
+                         * and the other is in the same column as the i-th key.
+                         */
+                        for (j = i + 1; j < num_down; j++) {
+                                u8 col = scancodes[j] & 0x07;
+                                u8 row = scancodes[j] >> KBC_ROW_SHIFT;
+
+                                if (col == curr_col)
+                                        key_in_same_col = true;
+                                if (row == curr_row)
+                                        key_in_same_row = true;
+                        }
+                }
+        }
+
+        /*
          * If the platform uses Fn keymaps, translate keys on a Fn keypress.
          * Function keycodes are KBC_MAX_KEY apart from the plain keycodes.
          */
@@ -297,6 +326,10 @@ static void tegra_kbc_report_keys(struct tegra_kbc *kbc)
 
         spin_unlock_irqrestore(&kbc->lock, flags);
 
+        /* Ignore the key presses for this iteration? */
+        if (key_in_same_col && key_in_same_row)
+                return;
+
         tegra_kbc_report_released_keys(kbc->idev,
                                        kbc->current_keys, kbc->num_pressed_keys,
                                        keycodes, num_down);
@@ -383,21 +416,11 @@ static void tegra_kbc_setup_wakekeys(struct tegra_kbc *kbc, bool filter)
         int i;
         unsigned int rst_val;
 
-        BUG_ON(pdata->wake_cnt > KBC_MAX_KEY);
-        rst_val = (filter && pdata->wake_cnt) ? ~0 : 0;
+        /* Either mask all keys or none. */
+        rst_val = (filter && !pdata->wakeup) ? ~0 : 0;
 
         for (i = 0; i < KBC_MAX_ROW; i++)
                 writel(rst_val, kbc->mmio + KBC_ROW0_MASK_0 + i * 4);
-
-        if (filter) {
-                for (i = 0; i < pdata->wake_cnt; i++) {
-                        u32 val, addr;
-                        addr = pdata->wake_cfg[i].row * 4 + KBC_ROW0_MASK_0;
-                        val = readl(kbc->mmio + addr);
-                        val &= ~(1 << pdata->wake_cfg[i].col);
-                        writel(val, kbc->mmio + addr);
-                }
-        }
 }
 
 static void tegra_kbc_config_pins(struct tegra_kbc *kbc)
@@ -559,7 +582,6 @@ static int __devinit tegra_kbc_probe(struct platform_device *pdev)
         struct resource *res;
         int irq;
         int err;
-        int i;
         int num_rows = 0;
         unsigned int debounce_cnt;
         unsigned int scan_time_rows;
@@ -616,13 +638,6 @@ static int __devinit tegra_kbc_probe(struct platform_device *pdev)
                 goto err_iounmap;
         }
 
-        kbc->wake_enable_rows = 0;
-        kbc->wake_enable_cols = 0;
-        for (i = 0; i < pdata->wake_cnt; i++) {
-                kbc->wake_enable_rows |= (1 << pdata->wake_cfg[i].row);
-                kbc->wake_enable_cols |= (1 << pdata->wake_cfg[i].col);
-        }
-
         /*
          * The time delay between two consecutive reads of the FIFO is
          * the sum of the repeat time and the time taken for scanning
@@ -652,6 +667,7 @@ static int __devinit tegra_kbc_probe(struct platform_device *pdev)
                 input_dev->keycodemax *= 2;
 
         kbc->use_fn_map = pdata->use_fn_map;
+        kbc->use_ghost_filter = pdata->use_ghost_filter;
         keymap_data = pdata->keymap_data ?: &tegra_kbc_default_keymap_data;
         matrix_keypad_build_keymap(keymap_data, KBC_ROW_SHIFT,
                                    input_dev->keycode, input_dev->keybit);