RE: [PATCH v5] input: tegra-kbc - Add tegra keyboard driver

-----Original Message-----
From: Dmitry Torokhov [mailto:dmitry.torokhov@gmail.com]
Sent: Monday, January 17, 2011 9:12 PM
To: Rakesh Iyer
Cc: tsoni@codeaurora.org; pavel@ucw.cz; shubhrajyoti@ti.com; ccross@android.com;
konkers@android.com; olof@lixom.net; Andrew Chew; linux-tegra@vger.kernel.org; linux-
kernel@vger.kernel.org; linux-input@vger.kernel.org
Subject: Re: [PATCH v5] input: tegra-kbc - Add tegra keyboard driver

On Thu, Jan 13, 2011 at 10:27:28AM -0800, riyer@nvidia.com wrote:

quoted

From: Rakesh Iyer <redacted>

This patch adds support for the internal matrix keyboard controller for
Nvidia Tegra platforms.

Signed-off-by: Rakesh Iyer <redacted>
---
Changes Done -
Wrap the users field check within the mutex.
Remove the KBC_MAX_KEYS define and use existing KBC_MAX_KEY.
Patch v4 was named incorrectly as PATCH 1/1, so skipping ahead to PATCH v5.

As I said, we should tty to reused definitions from matrix_keypad for
matrix keypads. Does the following still work for you?

Thanks.

--
Dmitry

Input: tegra-kbc - convert to use matrix-keypad definitions

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

and other miscellaneous rearrangements.

Signed-off-by: Dmitry Torokhov <redacted>
---

 arch/arm/mach-tegra/include/mach/kbc.h |   28 +
 drivers/input/keyboard/tegra-kbc.c     |  679 ++++++++++++++++++--------------
 2 files changed, 399 insertions(+), 308 deletions(-)

diff --git a/arch/arm/mach-tegra/include/mach/kbc.h b/arch/arm/mach-

tegra/include/mach/kbc.h
index 029a468..adb267f 100644

--- a/arch/arm/mach-tegra/include/mach/kbc.h
+++ b/arch/arm/mach-tegra/include/mach/kbc.h

@@ -1,6 +1,4 @@
 /*
- * kbc.h
- *
  * Platform definitions for tegra-kbc keyboard input driver
  *
  * Copyright (c) 2010, NVIDIA Corporation.

@@ -24,23 +22,18 @@
 #define ASMARM_ARCH_TEGRA_KBC_H

 #include <linux/types.h>
+#include <linux/input/matrix_keypad.h>

 #ifdef CONFIG_ARCH_TEGRA_2x_SOC
-#define KBC_MAX_GPIO 24
-#define KBC_MAX_KPENT 8
+#define KBC_MAX_GPIO 24
+#define KBC_MAX_KPENT        8
 #else
-#define KBC_MAX_GPIO 20
-#define KBC_MAX_KPENT 7
+#define KBC_MAX_GPIO 20
+#define KBC_MAX_KPENT        7
 #endif

-#define KBC_MAX_ROW 16
-#define KBC_MAX_COL 8
-
-#define KBC_MAX_KEY (KBC_MAX_ROW*KBC_MAX_COL)
-
 struct tegra_kbc_pin_cfg {
      bool is_row;
-     bool is_col;
      unsigned char num;
 };

@@ -52,10 +45,13 @@ struct tegra_kbc_wake_key {
 struct tegra_kbc_platform_data {
      unsigned int debounce_cnt;
      unsigned int repeat_cnt;
-     int wake_cnt; /* 0:wake on any key >1:wake on wake_cfg */
-     int *keycode;
-     bool wakeup;
+
+     unsigned int wake_cnt; /* 0:wake on any key >1:wake on wake_cfg */
+     const struct tegra_kbc_wake_key *wake_cfg;
+
      struct tegra_kbc_pin_cfg pin_cfg[KBC_MAX_GPIO];
-     struct tegra_kbc_wake_key *wake_cfg;
+     const struct matrix_keymap_data *keymap_data;
+
+     bool wakeup;
 };
 #endif

diff --git a/drivers/input/keyboard/tegra-kbc.c b/drivers/input/keyboard/tegra-kbc.c
index 02c8ece..a6ec3fc 100644
--- a/drivers/input/keyboard/tegra-kbc.c
+++ b/drivers/input/keyboard/tegra-kbc.c

@@ -1,6 +1,4 @@
 /*
- * tegra-kbc.c
- *
  * Keyboard class input driver for the NVIDIA Tegra SoC internal matrix
  * keyboard controller
  *

@@ -32,7 +30,7 @@
 #include <mach/clk.h>
 #include <mach/kbc.h>

-#define KBC_MAX_DEBOUNCE_CNT 0x3fful
+#define KBC_MAX_DEBOUNCE_CNT 0x3ffu

 /* KBC row scan time and delay for beginning the row scan. */
 #define KBC_ROW_SCAN_TIME    16

@@ -62,119 +60,201 @@
 #define KBC_KP_ENT1_0        0x34
 #define KBC_ROW0_MASK_0      0x38

+#define KBC_MAX_ROW  16
+#define KBC_MAX_COL  8
+#define KBC_ROW_SHIFT        3
+#define KBC_MAX_KEY  (KBC_MAX_ROW * KBC_MAX_COL)
+
 struct tegra_kbc {
      void __iomem *mmio;
      struct input_dev *idev;
-     int irq;
+     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;
-     int fifo[KBC_MAX_KPENT];
      const struct tegra_kbc_platform_data *pdata;
-     int keycode[KBC_MAX_KEY];
+     unsigned short keycode[KBC_MAX_KEY];
+     unsigned short current_keys[KBC_MAX_KPENT];
+     unsigned int num_pressed_keys;
      struct timer_list timer;
      struct clk *clk;
 };

-static int tegra_kbd_keycode[KBC_MAX_KEY] = {
-     KEY_RESERVED, KEY_RESERVED, KEY_W, KEY_S,
-             KEY_A, KEY_Z, KEY_RESERVED, KEY_FN,
-     KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
-             KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_MENU,
-     KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
-             KEY_RESERVED, KEY_RESERVED, KEY_RIGHTALT, KEY_LEFTALT,
-     KEY_5, KEY_4, KEY_R, KEY_E,
-             KEY_F, KEY_D, KEY_X, KEY_RESERVED,
-     KEY_7, KEY_6, KEY_T, KEY_H,
-             KEY_G, KEY_V, KEY_C, KEY_SPACE,
-     KEY_9, KEY_8, KEY_U, KEY_Y,
-             KEY_J, KEY_N, KEY_B, KEY_BACKSLASH,
-     KEY_MINUS, KEY_0, KEY_O, KEY_I,
-             KEY_L, KEY_K, KEY_COMMA, KEY_M,
-     KEY_RESERVED, KEY_EQUAL, KEY_RIGHTBRACE, KEY_ENTER,
-             KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_MENU,
-     KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
-             KEY_RIGHTSHIFT, KEY_LEFTSHIFT, KEY_RESERVED,

KEY_RESERVED,
-     KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
-             KEY_RESERVED, KEY_RIGHTCTRL, KEY_RESERVED, KEY_LEFTCTRL,
-     KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
-             KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
-     KEY_LEFTBRACE, KEY_P, KEY_APOSTROPHE, KEY_SEMICOLON,
-             KEY_SLASH, KEY_DOT, KEY_RESERVED, KEY_RESERVED,
-     KEY_F10, KEY_F9, KEY_BACKSPACE, KEY_3,
-             KEY_2, KEY_UP, KEY_PRINT, KEY_PAUSE,
-     KEY_INSERT, KEY_DELETE, KEY_RESERVED, KEY_PAGEUP,
-             KEY_PAGEDOWN, KEY_RIGHT, KEY_DOWN, KEY_LEFT,
-     KEY_F11, KEY_F12, KEY_F8, KEY_Q,
-             KEY_F4, KEY_F3, KEY_1, KEY_F7,
-     KEY_ESC, KEY_GRAVE, KEY_F5, KEY_TAB,
-             KEY_F1, KEY_F2, KEY_CAPSLOCK, KEY_F6
+static const u32 tegra_kbc_default_keymap[] = {
+     KEY(0, 2, KEY_W),
+     KEY(0, 3, KEY_S),
+     KEY(0, 4, KEY_A),
+     KEY(0, 5, KEY_Z),
+     KEY(0, 7, KEY_FN),
+
+     KEY(1, 7, KEY_MENU),
+
+     KEY(2, 6, KEY_RIGHTALT),
+     KEY(2, 7, KEY_LEFTALT),
+
+     KEY(3, 0, KEY_5),
+     KEY(3, 1, KEY_4),
+     KEY(3, 2, KEY_R),
+     KEY(3, 3, KEY_E),
+     KEY(3, 4, KEY_F),
+     KEY(3, 5, KEY_D),
+     KEY(3, 6, KEY_X),
+
+     KEY(4, 0, KEY_7),
+     KEY(4, 1, KEY_6),
+     KEY(4, 2, KEY_T),
+     KEY(4, 3, KEY_H),
+     KEY(4, 4, KEY_G),
+     KEY(4, 5, KEY_V),
+     KEY(4, 6, KEY_C),
+     KEY(4, 7, KEY_SPACE),
+
+     KEY(5, 0, KEY_9),
+     KEY(5, 1, KEY_8),
+     KEY(5, 2, KEY_U),
+     KEY(5, 3, KEY_Y),
+     KEY(5, 4, KEY_J),
+     KEY(5, 5, KEY_N),
+     KEY(5, 6, KEY_B),
+     KEY(5, 7, KEY_BACKSLASH),
+
+     KEY(6, 0, KEY_MINUS),
+     KEY(6, 1, KEY_0),
+     KEY(6, 2, KEY_O),
+     KEY(6, 3, KEY_I),
+     KEY(6, 4, KEY_L),
+     KEY(6, 5, KEY_K),
+     KEY(6, 6, KEY_COMMA),
+     KEY(6, 7, KEY_M),
+
+     KEY(7, 1, KEY_EQUAL),
+     KEY(7, 2, KEY_RIGHTBRACE),
+     KEY(7, 3, KEY_ENTER),
+     KEY(7, 7, KEY_MENU),
+
+     KEY(8, 4, KEY_RIGHTSHIFT),
+     KEY(8, 5, KEY_LEFTSHIFT),
+
+     KEY(9, 5, KEY_RIGHTCTRL),
+     KEY(9, 7, KEY_LEFTCTRL),
+
+     KEY(11, 0, KEY_LEFTBRACE),
+     KEY(11, 1, KEY_P),
+     KEY(11, 2, KEY_APOSTROPHE),
+     KEY(11, 3, KEY_SEMICOLON),
+     KEY(11, 4, KEY_SLASH),
+     KEY(11, 5, KEY_DOT),
+
+     KEY(12, 0, KEY_F10),
+     KEY(12, 1, KEY_F9),
+     KEY(12, 2, KEY_BACKSPACE),
+     KEY(12, 3, KEY_3),
+     KEY(12, 4, KEY_2),
+     KEY(12, 5, KEY_UP),
+     KEY(12, 6, KEY_PRINT),
+     KEY(12, 7, KEY_PAUSE),
+
+     KEY(13, 0, KEY_INSERT),
+     KEY(13, 1, KEY_DELETE),
+     KEY(13, 3, KEY_PAGEUP),
+     KEY(13, 4, KEY_PAGEDOWN),
+     KEY(13, 5, KEY_RIGHT),
+     KEY(13, 6, KEY_DOWN),
+     KEY(13, 7, KEY_LEFT),
+
+     KEY(14, 0, KEY_F11),
+     KEY(14, 1, KEY_F12),
+     KEY(14, 2, KEY_F8),
+     KEY(14, 3, KEY_Q),
+     KEY(14, 4, KEY_F4),
+     KEY(14, 5, KEY_F3),
+     KEY(14, 6, KEY_1),
+     KEY(14, 7, KEY_F7),
+
+     KEY(15, 0, KEY_ESC),
+     KEY(15, 1, KEY_GRAVE),
+     KEY(15, 2, KEY_F5),
+     KEY(15, 3, KEY_TAB),
+     KEY(15, 4, KEY_F1),
+     KEY(15, 5, KEY_F2),
+     KEY(15, 6, KEY_CAPSLOCK),
+     KEY(15, 7, KEY_F6),
 };

-static void tegra_kbc_report_keys(struct tegra_kbc *kbc, int *fifo)
-{
-     int curr_fifo[KBC_MAX_KPENT];
-     int rows_val[KBC_MAX_KPENT], cols_val[KBC_MAX_KPENT];
-     u32 kp_ent_val[(KBC_MAX_KPENT + 3) / 4];
-     u32 *kp_ents = kp_ent_val;
-     u32 kp_ent = 0;
-     unsigned long flags;
-     int i, j, valid = 0;
+static const struct matrix_keymap_data tegra_kbc_default_keymap_data = {
+     .keymap         = tegra_kbc_default_keymap,
+     .keymap_size    = ARRAY_SIZE(tegra_kbc_default_keymap),
+};

-     spin_lock_irqsave(&kbc->lock, flags);
-     for (i = 0; i < ARRAY_SIZE(kp_ent_val); i++)
-             kp_ent_val[i] = readl(kbc->mmio + KBC_KP_ENT0_0 + (i*4));
-     spin_unlock_irqrestore(&kbc->lock, flags);
+static void tegra_kbc_report_released_keys(struct input_dev *input,
+                                        unsigned short old_keycodes[],
+                                        unsigned int old_num_keys,
+                                        unsigned short new_keycodes[],
+                                        unsigned int new_num_keys)
+{
+     unsigned int i, j;

-     valid = 0;
-     for (i = 0; i < KBC_MAX_KPENT; i++) {
-             if (!(i&3))
-                     kp_ent = *kp_ents++;
+     for (i = 0; i < old_num_keys; i++) {
+             for (j = 0; j < new_num_keys; j++)
+                     if (old_keycodes[i] == new_keycodes[j])
+                             break;

-             if (kp_ent & 0x80) {
-                     cols_val[valid] = kp_ent & 0x7;
-                     rows_val[valid++] = (kp_ent >> 3) & 0xf;
-             }
-             kp_ent >>= 8;
+             if (j == new_num_keys)
+                     input_report_key(input, old_keycodes[i], 0);
      }
+}

-     j = 0;
-     for (i = 0; i < valid; i++) {
-             int k = kbc->keycode[(rows_val[i] * KBC_MAX_COL) + cols_val[i]];
-             if (likely(k != -1))
-                     curr_fifo[j++] = k;
+static void tegra_kbc_report_pressed_keys(struct input_dev *input,
+                                       unsigned char scancodes[],
+                                       unsigned short keycodes[],
+                                       unsigned int num_pressed_keys)
+{
+     unsigned int i;
+
+     for (i = 0; i < num_pressed_keys; i++) {
+             input_event(input, EV_MSC, MSC_SCAN, scancodes[i]);
+             input_report_key(input, keycodes[i], 1);
      }
-     valid = j;
+}
+
+static void tegra_kbc_report_keys(struct tegra_kbc *kbc)
+{
+     unsigned char scancodes[KBC_MAX_KPENT];
+     unsigned short keycodes[KBC_MAX_KPENT];
+     u32 val = 0;
+     unsigned int i;
+     unsigned int num_down = 0;
+     unsigned long flags;

+     spin_lock_irqsave(&kbc->lock, flags);
      for (i = 0; i < KBC_MAX_KPENT; i++) {
-             if (fifo[i] == -1)
-                     continue;
-             for (j = 0; j < valid; j++) {
-                     if (curr_fifo[j] == fifo[i]) {
-                             curr_fifo[j] = -1;
-                             break;
-                     }
-             }
-             if (j == valid) {
-                     input_report_key(kbc->idev, fifo[i], 0);
-                     fifo[i] = -1;
-             }
-     }
-     for (j = 0; j < valid; j++) {
-             if (curr_fifo[j] == -1)
-                     continue;
-             for (i = 0; i < KBC_MAX_KPENT; i++) {
-                     if (fifo[i] == -1)
-                             break;
+             if ((i % 4) == 0)
+                     val = readl(kbc->mmio + KBC_KP_ENT0_0 + (i * 4));
+
+             if (val & 0x80) {
+                     unsigned int col = val & 0x07;
+                     unsigned int row = (val >> 3) & 0x0f;
+                     unsigned char scancode =
+                             MATRIX_SCAN_CODE(row, col, KBC_ROW_SHIFT);
+
+                     scancodes[num_down] = scancode;
+                     keycodes[num_down++] = kbc->keycode[scancode];
              }
-             if (i != KBC_MAX_KPENT) {
-                     fifo[i] = curr_fifo[j];
-                     input_report_key(kbc->idev, fifo[i], 1);
-             } else
-                     WARN_ON(1);
+
+             val >>= 8;
      }
+     spin_unlock_irqrestore(&kbc->lock, flags);
+
+     tegra_kbc_report_released_keys(kbc->idev,
+                                    kbc->current_keys, kbc->num_pressed_keys,
+                                    keycodes, num_down);
+     tegra_kbc_report_pressed_keys(kbc->idev, scancodes, keycodes, num_down);
+     input_sync(kbc->idev);
+
+     memcpy(kbc->current_keys, keycodes, sizeof(kbc->current_keys));
+     kbc->num_pressed_keys = num_down;
 }

 static void tegra_kbc_keypress_timer(unsigned long data)

@@ -182,26 +262,27 @@ static void tegra_kbc_keypress_timer(unsigned long data)
      struct tegra_kbc *kbc = (struct tegra_kbc *)data;
      unsigned long flags;
      u32 val;
-     int i;
+     unsigned int i;

      val = (readl(kbc->mmio + KBC_INT_0) >> 4) & 0xf;
      if (val) {
              unsigned long dly;

-             tegra_kbc_report_keys(kbc, kbc->fifo);
+             tegra_kbc_report_keys(kbc);

-             /* If more than one keys are pressed we need not wait
-              * for the repoll delay. */
+             /*
+              * If more than one keys are pressed we need not wait
+              * for the repoll delay.
+              */
              dly = (val == 1) ? kbc->repoll_dly : 1;
              mod_timer(&kbc->timer, jiffies + msecs_to_jiffies(dly));
      } else {
-             /* release any pressed keys and exit the loop */
-             for (i = 0; i < ARRAY_SIZE(kbc->fifo); i++) {
-                     if (kbc->fifo[i] == -1)
-                             continue;
-                     input_report_key(kbc->idev, kbc->fifo[i], 0);
-                     kbc->fifo[i] = -1;
-             }
+             /* Release any pressed keys and exit the polling loop */
+             for (i = 0; i < kbc->num_pressed_keys; i++)
+                     input_report_key(kbc->idev, kbc->current_keys[i], 0);
+             input_sync(kbc->idev);
+
+             kbc->num_pressed_keys = 0;

              /* All keys are released so enable the keypress interrupt */
              spin_lock_irqsave(&kbc->lock, flags);

@@ -212,38 +293,58 @@ static void tegra_kbc_keypress_timer(unsigned long data)
      }
 }

-static void tegra_kbc_close(struct input_dev *dev)
+static irqreturn_t tegra_kbc_isr(int irq, void *args)
 {
-     struct tegra_kbc *kbc = input_get_drvdata(dev);
-     unsigned long flags;
-     u32 val;
+     struct tegra_kbc *kbc = args;
+     u32 val, ctl;

-     spin_lock_irqsave(&kbc->lock, flags);
-     val = readl(kbc->mmio + KBC_CONTROL_0);
-     val &= ~1;
-     writel(val, kbc->mmio + KBC_CONTROL_0);
-     spin_unlock_irqrestore(&kbc->lock, flags);
+     /*
+      * Until all keys are released, defer further processing to
+      * the polling loop in tegra_kbc_keypress_timer
+      */
+     ctl = readl(kbc->mmio + KBC_CONTROL_0);
+     ctl &= ~KBC_CONTROL_FIFO_CNT_INT_EN;
+     writel(ctl, kbc->mmio + KBC_CONTROL_0);

-     clk_disable(kbc->clk);
+     /*
+      * Quickly bail out & reenable interrupts if the fifo threshold
+      * count interrupt wasn't the interrupt source
+      */
+     val = readl(kbc->mmio + KBC_INT_0);
+     writel(val, kbc->mmio + KBC_INT_0);
+
+     if (val & KBC_INT_FIFO_CNT_INT_STATUS) {
+             /*
+              * Schedule timer to run when hardware is in continuous
+              * polling mode.
+              */
+             mod_timer(&kbc->timer, jiffies + kbc->cp_dly_jiffies);
+     } else {
+             ctl |= KBC_CONTROL_FIFO_CNT_INT_EN;
+             writel(ctl, kbc->mmio + KBC_CONTROL_0);
+     }
+
+     return IRQ_HANDLED;
 }

 static void tegra_kbc_setup_wakekeys(struct tegra_kbc *kbc, bool filter)
 {
+     const struct tegra_kbc_platform_data *pdata = kbc->pdata;
      int i;
      unsigned int rst_val;

-     BUG_ON(kbc->pdata->wake_cnt > KBC_MAX_KEY);
-     rst_val = (filter && kbc->pdata->wake_cnt) ? ~0 : 0;
+     BUG_ON(pdata->wake_cnt > KBC_MAX_KEY);
+     rst_val = (filter && pdata->wake_cnt) ? ~0 : 0;

      for (i = 0; i < KBC_MAX_ROW; i++)
-             writel(rst_val, kbc->mmio+KBC_ROW0_MASK_0+i*4);
+             writel(rst_val, kbc->mmio + KBC_ROW0_MASK_0 + i * 4);

      if (filter) {
-             for (i = 0; i < kbc->pdata->wake_cnt; i++) {
+             for (i = 0; i < pdata->wake_cnt; i++) {
                      u32 val, addr;
-                     addr = kbc->pdata->wake_cfg[i].row*4 + KBC_ROW0_MASK_0;
+                     addr = pdata->wake_cfg[i].row * 4 + KBC_ROW0_MASK_0;
                      val = readl(kbc->mmio + addr);
-                     val &= ~(1<<kbc->pdata->wake_cfg[i].col);
+                     val &= ~(1 << pdata->wake_cfg[i].col);
                      writel(val, kbc->mmio + addr);
              }
      }

@@ -255,33 +356,31 @@ static void tegra_kbc_config_pins(struct tegra_kbc *kbc)
      int i;

      for (i = 0; i < KBC_MAX_GPIO; i++) {
-             u32 row_cfg, col_cfg;
-             u32 r_shift = 5 * (i%6);
-             u32 c_shift = 4 * (i%8);
+             u32 r_shift = 5 * (i % 6);
+             u32 c_shift = 4 * (i % 8);
              u32 r_mask = 0x1f << r_shift;
-             u32 c_mask = 0xf << c_shift;
+             u32 c_mask = 0x0f << c_shift;
              u32 r_offs = (i / 6) * 4 + KBC_ROW_CFG0_0;
              u32 c_offs = (i / 8) * 4 + KBC_COL_CFG0_0;
-
-             row_cfg = readl(kbc->mmio + r_offs);
-             col_cfg = readl(kbc->mmio + c_offs);
+             u32 row_cfg = readl(kbc->mmio + r_offs);
+             u32 col_cfg = readl(kbc->mmio + c_offs);

              row_cfg &= ~r_mask;
              col_cfg &= ~c_mask;

              if (pdata->pin_cfg[i].is_row)
-                     row_cfg |= ((pdata->pin_cfg[i].num<<1) | 1) << r_shift;
-             else if (pdata->pin_cfg[i].is_col)
-                     col_cfg |= ((pdata->pin_cfg[i].num<<1) | 1) << c_shift;
+                     row_cfg |= ((pdata->pin_cfg[i].num << 1) | 1) << r_shift;
+             else
+                     col_cfg |= ((pdata->pin_cfg[i].num << 1) | 1) << c_shift;

              writel(row_cfg, kbc->mmio + r_offs);
              writel(col_cfg, kbc->mmio + c_offs);
      }
 }

-static int tegra_kbc_open(struct input_dev *dev)
+static int tegra_kbc_start(struct tegra_kbc *kbc)
 {
-     struct tegra_kbc *kbc = input_get_drvdata(dev);
+     const struct tegra_kbc_platform_data *pdata = kbc->pdata;
      unsigned long flags;
      unsigned int debounce_cnt;
      u32 val = 0;

@@ -297,98 +396,120 @@ static int tegra_kbc_open(struct input_dev *dev)
      tegra_kbc_config_pins(kbc);
      tegra_kbc_setup_wakekeys(kbc, false);

-     writel(kbc->pdata->repeat_cnt, kbc->mmio + KBC_RPT_DLY_0);
+     writel(pdata->repeat_cnt, kbc->mmio + KBC_RPT_DLY_0);

      /* Keyboard debounce count is maximum of 12 bits. */
-     debounce_cnt = kbc->pdata->debounce_cnt;
-     debounce_cnt = min_t(unsigned int, debounce_cnt, KBC_MAX_DEBOUNCE_CNT);
+     debounce_cnt = min(pdata->debounce_cnt, KBC_MAX_DEBOUNCE_CNT);
      val = KBC_DEBOUNCE_CNT_SHIFT(debounce_cnt);
      val |= KBC_FIFO_TH_CNT_SHIFT(1); /* set fifo interrupt threshold to 1 */
      val |= KBC_CONTROL_FIFO_CNT_INT_EN;  /* interrupt on FIFO threshold */
      val |= KBC_CONTROL_KBC_EN;     /* enable */
      writel(val, kbc->mmio + KBC_CONTROL_0);

-     /* Compute the delay(ns) from interrupt mode to continuous polling mode
-      * so the timer routine is scheduled appropriately. */
+     /*
+      * Compute the delay(ns) from interrupt mode to continuous polling
+      * mode so the timer routine is scheduled appropriately.
+      */
      val = readl(kbc->mmio + KBC_INIT_DLY_0);
      kbc->cp_dly_jiffies = usecs_to_jiffies((val & 0xfffff) * 32);

-     /* atomically clear out any remaining entries in the key FIFO
-      * and enable keyboard interrupts */
+     kbc->num_pressed_keys = 0;
+
+     /*
+      * Atomically clear out any remaining entries in the key FIFO
+      * and enable keyboard interrupts.
+      */
      spin_lock_irqsave(&kbc->lock, flags);
      while (1) {
              val = readl(kbc->mmio + KBC_INT_0);
              val >>= 4;
-             if (val) {
-                     val = readl(kbc->mmio + KBC_KP_ENT0_0);
-                     val = readl(kbc->mmio + KBC_KP_ENT1_0);
-             } else {
+             if (!val)
                      break;
-             }
+
+             val = readl(kbc->mmio + KBC_KP_ENT0_0);
+             val = readl(kbc->mmio + KBC_KP_ENT1_0);
      }
      writel(0x7, kbc->mmio + KBC_INT_0);
      spin_unlock_irqrestore(&kbc->lock, flags);

+     enable_irq(kbc->irq);
+
      return 0;
 }

-
-static int __devexit tegra_kbc_remove(struct platform_device *pdev)
+static void tegra_kbc_stop( struct tegra_kbc *kbc)
 {
-     struct tegra_kbc *kbc = platform_get_drvdata(pdev);
-     struct resource *res;
+     unsigned long flags;
+     u32 val;

-     free_irq(kbc->irq, pdev);
+     spin_lock_irqsave(&kbc->lock, flags);
+     val = readl(kbc->mmio + KBC_CONTROL_0);
+     val &= ~1;
+     writel(val, kbc->mmio + KBC_CONTROL_0);
+     spin_unlock_irqrestore(&kbc->lock, flags);
+
+     disable_irq(kbc->irq);
      del_timer_sync(&kbc->timer);
+
      clk_disable(kbc->clk);
-     clk_put(kbc->clk);
+}

-     input_unregister_device(kbc->idev);
-     iounmap(kbc->mmio);
-     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-     release_mem_region(res->start, resource_size(res));
+static int tegra_kbc_open(struct input_dev *dev)
+{
+     struct tegra_kbc *kbc = input_get_drvdata(dev);

-     kfree(kbc);
-     return 0;
+     return tegra_kbc_start(kbc);
 }

-static irqreturn_t tegra_kbc_isr(int irq, void *args)
+static void tegra_kbc_close(struct input_dev *dev)
 {
-     struct tegra_kbc *kbc = args;
-     u32 val, ctl;
+     struct tegra_kbc *kbc = input_get_drvdata(dev);

-     /* until all keys are released, defer further processing to
-      * the polling loop in tegra_kbc_keypress_timer */
-     ctl = readl(kbc->mmio + KBC_CONTROL_0);
-     ctl &= ~KBC_CONTROL_FIFO_CNT_INT_EN;
-     writel(ctl, kbc->mmio + KBC_CONTROL_0);
+     return tegra_kbc_stop(kbc);
+}

-     /* quickly bail out & reenable interrupts if the fifo threshold count
-      * interrupt wasn't the interrupt source */
-     val = readl(kbc->mmio + KBC_INT_0);
-     writel(val, kbc->mmio + KBC_INT_0);
+static bool __devinit
+tegra_kbc_check_pin_cfg(const struct tegra_kbc_platform_data *pdata,
+                     struct device *dev, unsigned int *num_rows)
+{
+     int i;

-     if (!(val & KBC_INT_FIFO_CNT_INT_STATUS)) {
-             ctl |= KBC_CONTROL_FIFO_CNT_INT_EN;
-             writel(ctl, kbc->mmio + KBC_CONTROL_0);
-             return IRQ_HANDLED;
+     *num_rows = 0;
+
+     for (i = 0; i < KBC_MAX_GPIO; i++) {
+             const struct tegra_kbc_pin_cfg *pin_cfg = &pdata->pin_cfg[i];
+
+             if (pin_cfg->is_row) {
+                     if (pin_cfg->num >= KBC_MAX_ROW) {
+                             dev_err(dev,
+                                     "pin_cfg[%d]: invalid row number %d\n",
+                                     i, pin_cfg->num);
+                             return false;
+                     }
+                     (*num_rows)++;
+             } else {
+                     if (pin_cfg->num >= KBC_MAX_COL) {
+                             dev_err(dev,
+                                     "pin_cfg[%d]: invalid column number %d\n",
+                                     i, pin_cfg->num);
+                             return false;
+                     }
+             }
      }

-     /* Schedule timer to run when hardware is in continuous polling mode. */
-     mod_timer(&kbc->timer, jiffies + kbc->cp_dly_jiffies);
-     return IRQ_HANDLED;
+     return true;
 }

 static int __devinit tegra_kbc_probe(struct platform_device *pdev)
 {
-     struct tegra_kbc *kbc;
      const struct tegra_kbc_platform_data *pdata = pdev->dev.platform_data;
+     const struct matrix_keymap_data *keymap_data;
+     struct tegra_kbc *kbc;
+     struct input_dev *input_dev;
      struct resource *res;
      int irq;
      int err;
-     int rows[KBC_MAX_ROW];
-     int cols[KBC_MAX_COL];
-     int i, j;
+     int i;
      int num_rows = 0;
      unsigned int debounce_cnt;
      unsigned int scan_time_rows;

@@ -396,173 +517,147 @@ static int __devinit tegra_kbc_probe(struct platform_device

*pdev)
      if (!pdata)
              return -EINVAL;

-     kbc = kzalloc(sizeof(*kbc), GFP_KERNEL);
-     if (!kbc)
-             return -ENOMEM;
+     if (!tegra_kbc_check_pin_cfg(pdata, &pdev->dev, &num_rows))
+             return -EINVAL;

-     kbc->pdata = pdata;
-     kbc->irq = -EINVAL;
+     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+     if (!res) {
+             dev_err(&pdev->dev, "failed to get I/O memory\n");
+             return -ENXIO;
+     }

-     memset(rows, 0, sizeof(rows));
-     memset(cols, 0, sizeof(cols));
+     irq = platform_get_irq(pdev, 0);
+     if (irq < 0) {
+             dev_err(&pdev->dev, "failed to get keyboard IRQ\n");
+             return -ENXIO;
+     }

-     kbc->idev = input_allocate_device();
-     if (!kbc->idev) {
+     kbc = kzalloc(sizeof(*kbc), GFP_KERNEL);
+     input_dev = input_allocate_device();
+     if (!kbc || !input_dev) {
              err = -ENOMEM;
-             goto fail_allocateinput;
+             goto err_free_mem;
      }

-     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-     if (!res) {
-             dev_err(&pdev->dev, "failed to get I/O memory\n");
-             err = -ENXIO;
-             goto fail_memoryresource;
-     }
+     kbc->pdata = pdata;
+     kbc->idev = input_dev;
+     kbc->irq = irq;
+     spin_lock_init(&kbc->lock);
+     setup_timer(&kbc->timer, tegra_kbc_keypress_timer, (unsigned long)kbc);
+
      res = request_mem_region(res->start, resource_size(res), pdev->name);
      if (!res) {
              dev_err(&pdev->dev, "failed to request I/O memory\n");
              err = -EBUSY;
-             goto fail_memoryresource;
+             goto err_free_mem;
      }
+
      kbc->mmio = ioremap(res->start, resource_size(res));
      if (!kbc->mmio) {
              dev_err(&pdev->dev, "failed to remap I/O memory\n");
              err = -ENXIO;
-             goto fail_memoryresource;
-     }
-     irq = platform_get_irq(pdev, 0);
-     if (irq < 0) {
-             dev_err(&pdev->dev, "failed to get keyboard IRQ\n");
-             err = -ENXIO;
-             goto fail_keyboardresource;
+             goto err_free_mem_region;
      }
+
      kbc->clk = clk_get(&pdev->dev, NULL);
-     if (IS_ERR_OR_NULL(kbc->clk)) {
+     if (IS_ERR(kbc->clk)) {
              dev_err(&pdev->dev, "failed to get keyboard clock\n");
-             err = (kbc->clk) ? PTR_ERR(kbc->clk) : -ENODEV;
-             kbc->clk = NULL;
-             goto fail_keyboardresource;
+             err = PTR_ERR(kbc->clk);
+             goto err_iounmap;
      }

-     platform_set_drvdata(pdev, kbc);
-
-     kbc->idev->name = pdev->name;
-     input_set_drvdata(kbc->idev, kbc);
-     kbc->idev->id.bustype = BUS_HOST;
-     kbc->idev->open = tegra_kbc_open;
-     kbc->idev->close = tegra_kbc_close;
-     kbc->idev->dev.parent = &pdev->dev;
-     spin_lock_init(&kbc->lock);
-
-     for (i = 0; i < KBC_MAX_GPIO; i++) {
-             if (pdata->pin_cfg[i].is_row && pdata->pin_cfg[i].is_col) {
-                     dev_err(&pdev->dev, "invalid pin configuration data\n");
-                     err = -EINVAL;
-                     goto fail_configurekeyboard;
-             }
-
-             if (pdata->pin_cfg[i].is_row) {
-                     if (pdata->pin_cfg[i].num >= KBC_MAX_ROW) {
-                             dev_err(&pdev->dev, "invalid row number\n");
-                             err = -EINVAL;
-                             goto fail_configurekeyboard;
-                     }
-                     rows[pdata->pin_cfg[i].num] = 1;
-                     num_rows++;
-             } else if (pdata->pin_cfg[i].is_col) {
-                     if (pdata->pin_cfg[i].num >= KBC_MAX_COL) {
-                             dev_err(&pdev->dev, "invalid column number\n");
-                             err = -EINVAL;
-                             goto fail_configurekeyboard;
-                     }
-                     cols[pdata->pin_cfg[i].num] = 1;
-             }
-     }
      kbc->wake_enable_rows = 0;
      kbc->wake_enable_cols = 0;
-
      for (i = 0; i < pdata->wake_cnt; i++) {
-             kbc->wake_enable_rows |= (1 << kbc->pdata->wake_cfg[i].row);
-             kbc->wake_enable_cols |= (1 << kbc->pdata->wake_cfg[i].col);
+             kbc->wake_enable_rows |= (1 << pdata->wake_cfg[i].row);
+             kbc->wake_enable_cols |= (1 << pdata->wake_cfg[i].col);
      }

-     debounce_cnt = pdata->debounce_cnt;
-     debounce_cnt = min_t(unsigned int, debounce_cnt, KBC_MAX_DEBOUNCE_CNT);
-
-     /* The time delay between two consecutive reads of the FIFO is the sum
-      * of the repeat time and the time taken for scanning the rows.
-      * There is an additional delay before the row scanning starts.
-      * The repoll delay is computed in milliseconds. */
+     /*
+      * The time delay between two consecutive reads of the FIFO is
+      * the sum of the repeat time and the time taken for scanning
+      * the rows. There is an additional delay before the row scanning
+      * starts. The repoll delay is computed in milliseconds.
+      */
+     debounce_cnt = min(pdata->debounce_cnt, KBC_MAX_DEBOUNCE_CNT);
      scan_time_rows = (KBC_ROW_SCAN_TIME + debounce_cnt) * num_rows;
      kbc->repoll_dly = KBC_ROW_SCAN_DLY + scan_time_rows + pdata->repeat_cnt;
      kbc->repoll_dly = ((kbc->repoll_dly * KBC_CYCLE_USEC) + 999) / 1000;

-     kbc->idev->evbit[0] = BIT_MASK(EV_KEY);
+     input_dev->name = pdev->name;
+     input_dev->id.bustype = BUS_HOST;
+     input_dev->dev.parent = &pdev->dev;
+     input_dev->open = tegra_kbc_open;
+     input_dev->close = tegra_kbc_close;

-     /* Override the default keycodes with the board supplied ones. */
-     if (pdata->keycode)
-             memcpy(kbc->keycode, pdata->keycode, sizeof(kbc->keycode));
-     else
-             memcpy(kbc->keycode, tegra_kbd_keycode, sizeof(kbc->keycode));
+     input_set_drvdata(input_dev, kbc);

-     kbc->idev->keycode = kbc->keycode;
-     kbc->idev->keycodesize = sizeof(kbc->keycode[0]);
-     kbc->idev->keycodemax = ARRAY_SIZE(kbc->keycode);
+     input_dev->evbit[0] = BIT_MASK(EV_KEY);
+     input_set_capability(input_dev, EV_MSC, MSC_SCAN);

-     for (i = 0; i < KBC_MAX_COL; i++) {
-             if (!cols[i])
-                     continue;
-             for (j = 0; j < KBC_MAX_ROW; j++) {
-                     int keycode;
+     input_dev->keycode = kbc->keycode;
+     input_dev->keycodesize = sizeof(kbc->keycode[0]);
+     input_dev->keycodemax = ARRAY_SIZE(kbc->keycode);

-                     if (!rows[j])
-                             continue;
+     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);

-                     /* enable all the mapped keys. */
-                     keycode = kbc->keycode[(j * KBC_MAX_COL) + i];
-                     if (keycode != -1)
-                             set_bit(keycode, kbc->idev->keybit);
-
-             }
-     }
-
-     setup_timer(&kbc->timer, tegra_kbc_keypress_timer, (unsigned long)kbc);
-     /* Initialize the FIFO to invalid entries */
-     for (i = 0; i < ARRAY_SIZE(kbc->fifo); i++)
-             kbc->fifo[i] = -1;
-
-     /* keycode FIFO needs to be read atomically; leave local
-      * interrupts disabled when handling KBC interrupt */
-     err = request_irq(irq, tegra_kbc_isr, IRQF_TRIGGER_HIGH,
-             pdev->name, kbc);
+     err = request_irq(kbc->irq, tegra_kbc_isr, IRQF_TRIGGER_HIGH,
+                       pdev->name, kbc);
      if (err) {
              dev_err(&pdev->dev, "failed to request keyboard IRQ\n");
-             goto fail_configurekeyboard;
+             goto err_put_clk;
      }
-     kbc->irq = irq;
+
+     disable_irq(kbc->irq);

      err = input_register_device(kbc->idev);
      if (err) {
              dev_err(&pdev->dev, "failed to register input device\n");
-             goto fail_registerinput;
+             goto err_free_irq;
      }

+     platform_set_drvdata(pdev, kbc);
      device_init_wakeup(&pdev->dev, pdata->wakeup);
+
      return 0;

-fail_registerinput:
+err_free_irq:
      free_irq(kbc->irq, pdev);
-fail_configurekeyboard:
+err_put_clk:
      clk_put(kbc->clk);
-fail_keyboardresource:
+err_iounmap:
      iounmap(kbc->mmio);
-fail_memoryresource:
+err_free_mem_region:
+     release_mem_region(res->start, resource_size(res));
+err_free_mem:
      input_free_device(kbc->idev);
-fail_allocateinput:
      kfree(kbc);
+
      return err;
 }

+static int __devexit tegra_kbc_remove(struct platform_device *pdev)
+{
+     struct tegra_kbc *kbc = platform_get_drvdata(pdev);
+     struct resource *res;
+
+     free_irq(kbc->irq, pdev);
+     clk_put(kbc->clk);
+
+     input_unregister_device(kbc->idev);
+     iounmap(kbc->mmio);
+     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+     release_mem_region(res->start, resource_size(res));
+
+     kfree(kbc);
+
+     platform_set_drvdata(pdev, NULL);
+
+     return 0;
+}
+
 #ifdef CONFIG_PM
 static int tegra_kbc_suspend(struct platform_device *pdev, pm_message_t state)
 {

@@ -577,7 +672,7 @@ static int tegra_kbc_suspend(struct platform_device *pdev,

pm_message_t state)
      } else {
              mutex_lock(&kbc->idev->mutex);
              if (kbc->idev->users)
-                     tegra_kbc_close(kbc->idev);
+                     tegra_kbc_stop(kbc);
              mutex_unlock(&kbc->idev->mutex);
      }

@@ -595,7 +690,7 @@ static int tegra_kbc_resume(struct platform_device *pdev)
      } else {
              mutex_lock(&kbc->idev->mutex);
              if (kbc->idev->users)
-                     err = tegra_kbc_open(kbc->idev);
+                     err = tegra_kbc_start(kbc);
              mutex_unlock(&kbc->idev->mutex);
      }