Input: tegra-kbc - add tegra keyboard driver

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

Signed-off-by: Rakesh Iyer <riyer@nvidia.com>
Reviewed-by: Trilok Soni <tsoni@codeaurora.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

arch/arm/mach-tegra/include/mach/kbc.h

@@ -0,0 +1,61 @@
+/*
+ * Platform definitions for tegra-kbc keyboard input driver
+ *
+ * Copyright (c) 2010-2011, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#ifndef ASMARM_ARCH_TEGRA_KBC_H
+#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
+#else
+#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;
+	unsigned char num;
+};
+
+struct tegra_kbc_wake_key {
+	u8 row:4;
+	u8 col:4;
+};
+
+struct tegra_kbc_platform_data {
+	unsigned int debounce_cnt;
+	unsigned int repeat_cnt;
+
+	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];
+	const struct matrix_keymap_data *keymap_data;
+
+	bool wakeup;
+};
+#endif

drivers/input/keyboard/Kconfig

@@ -343,6 +343,16 @@ config KEYBOARD_NOMADIK
 	  To compile this driver as a module, choose M here: the
 	  module will be called nmk-ske-keypad.
 
+config KEYBOARD_TEGRA
+	tristate "NVIDIA Tegra internal matrix keyboard controller support"
+	depends on ARCH_TEGRA
+	help
+	  Say Y here if you want to use a matrix keyboard connected directly
+	  to the internal keyboard controller on Tegra SoCs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called tegra-kbc.
+
 config KEYBOARD_OPENCORES
 	tristate "OpenCores Keyboard Controller"
 	help

drivers/input/keyboard/Makefile

@@ -41,6 +41,7 @@ obj-$(CONFIG_KEYBOARD_SPEAR)		+= spear-keyboard.o
 obj-$(CONFIG_KEYBOARD_STMPE)		+= stmpe-keypad.o
 obj-$(CONFIG_KEYBOARD_STOWAWAY)		+= stowaway.o
 obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
+obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
 obj-$(CONFIG_KEYBOARD_TNETV107X)	+= tnetv107x-keypad.o
 obj-$(CONFIG_KEYBOARD_TWL4030)		+= twl4030_keypad.o
 obj-$(CONFIG_KEYBOARD_XTKBD)		+= xtkbd.o

drivers/input/keyboard/tegra-kbc.c

@@ -0,0 +1,727 @@
+/*
+ * Keyboard class input driver for the NVIDIA Tegra SoC internal matrix
+ * keyboard controller
+ *
+ * Copyright (c) 2009-2011, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <mach/clk.h>
+#include <mach/kbc.h>
+
+#define KBC_MAX_DEBOUNCE_CNT	0x3ffu
+
+/* KBC row scan time and delay for beginning the row scan. */
+#define KBC_ROW_SCAN_TIME	16
+#define KBC_ROW_SCAN_DLY	5
+
+/* KBC uses a 32KHz clock so a cycle = 1/32Khz */
+#define KBC_CYCLE_USEC	32
+
+/* KBC Registers */
+
+/* KBC Control Register */
+#define KBC_CONTROL_0	0x0
+#define KBC_FIFO_TH_CNT_SHIFT(cnt)	(cnt << 14)
+#define KBC_DEBOUNCE_CNT_SHIFT(cnt)	(cnt << 4)
+#define KBC_CONTROL_FIFO_CNT_INT_EN	(1 << 3)
+#define KBC_CONTROL_KBC_EN		(1 << 0)
+
+/* KBC Interrupt Register */
+#define KBC_INT_0	0x4
+#define KBC_INT_FIFO_CNT_INT_STATUS	(1 << 2)
+
+#define KBC_ROW_CFG0_0	0x8
+#define KBC_COL_CFG0_0	0x18
+#define KBC_INIT_DLY_0	0x28
+#define KBC_RPT_DLY_0	0x2c
+#define KBC_KP_ENT0_0	0x30
+#define KBC_KP_ENT1_0	0x34
+#define KBC_ROW0_MASK_0	0x38
+
+#define KBC_ROW_SHIFT	3
+
+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;
+	const struct tegra_kbc_platform_data *pdata;
+	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 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 const struct matrix_keymap_data tegra_kbc_default_keymap_data = {
+	.keymap		= tegra_kbc_default_keymap,
+	.keymap_size	= ARRAY_SIZE(tegra_kbc_default_keymap),
+};
+
+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;
+
+	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 (j == new_num_keys)
+			input_report_key(input, old_keycodes[i], 0);
+	}
+}
+
+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);
+	}
+}
+
+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 ((i % 4) == 0)
+			val = readl(kbc->mmio + KBC_KP_ENT0_0 + i);
+
+		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];
+		}
+
+		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)
+{
+	struct tegra_kbc *kbc = (struct tegra_kbc *)data;
+	unsigned long flags;
+	u32 val;
+	unsigned int i;
+
+	val = (readl(kbc->mmio + KBC_INT_0) >> 4) & 0xf;
+	if (val) {
+		unsigned long dly;
+
+		tegra_kbc_report_keys(kbc);
+
+		/*
+		 * 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 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);
+		val = readl(kbc->mmio + KBC_CONTROL_0);
+		val |= KBC_CONTROL_FIFO_CNT_INT_EN;
+		writel(val, kbc->mmio + KBC_CONTROL_0);
+		spin_unlock_irqrestore(&kbc->lock, flags);
+	}
+}
+
+static irqreturn_t tegra_kbc_isr(int irq, void *args)
+{
+	struct tegra_kbc *kbc = args;
+	u32 val, ctl;
+
+	/*
+	 * 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);
+
+	/*
+	 * 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(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);
+
+	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)
+{
+	const struct tegra_kbc_platform_data *pdata = kbc->pdata;
+	int i;
+
+	for (i = 0; i < KBC_MAX_GPIO; i++) {
+		u32 r_shft = 5 * (i % 6);
+		u32 c_shft = 4 * (i % 8);
+		u32 r_mask = 0x1f << r_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;
+		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_shft;
+		else
+			col_cfg |= ((pdata->pin_cfg[i].num << 1) | 1) << c_shft;
+
+		writel(row_cfg, kbc->mmio + r_offs);
+		writel(col_cfg, kbc->mmio + c_offs);
+	}
+}
+
+static int tegra_kbc_start(struct tegra_kbc *kbc)
+{
+	const struct tegra_kbc_platform_data *pdata = kbc->pdata;
+	unsigned long flags;
+	unsigned int debounce_cnt;
+	u32 val = 0;
+
+	clk_enable(kbc->clk);
+
+	/* Reset the KBC controller to clear all previous status.*/
+	tegra_periph_reset_assert(kbc->clk);
+	udelay(100);
+	tegra_periph_reset_deassert(kbc->clk);
+	udelay(100);
+
+	tegra_kbc_config_pins(kbc);
+	tegra_kbc_setup_wakekeys(kbc, false);
+
+	writel(pdata->repeat_cnt, kbc->mmio + KBC_RPT_DLY_0);
+
+	/* Keyboard debounce count is maximum of 12 bits. */
+	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.
+	 */
+	val = readl(kbc->mmio + KBC_INIT_DLY_0);
+	kbc->cp_dly_jiffies = usecs_to_jiffies((val & 0xfffff) * 32);
+
+	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)
+			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 void tegra_kbc_stop(struct tegra_kbc *kbc)
+{
+	unsigned long flags;
+	u32 val;
+
+	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);
+}
+
+static int tegra_kbc_open(struct input_dev *dev)
+{
+	struct tegra_kbc *kbc = input_get_drvdata(dev);
+
+	return tegra_kbc_start(kbc);
+}
+
+static void tegra_kbc_close(struct input_dev *dev)
+{
+	struct tegra_kbc *kbc = input_get_drvdata(dev);
+
+	return tegra_kbc_stop(kbc);
+}
+
+static bool __devinit
+tegra_kbc_check_pin_cfg(const struct tegra_kbc_platform_data *pdata,
+			struct device *dev, unsigned int *num_rows)
+{
+	int i;
+
+	*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;
+			}
+		}
+	}
+
+	return true;
+}
+
+static int __devinit tegra_kbc_probe(struct platform_device *pdev)
+{
+	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 i;
+	int num_rows = 0;
+	unsigned int debounce_cnt;
+	unsigned int scan_time_rows;
+
+	if (!pdata)
+		return -EINVAL;
+
+	if (!tegra_kbc_check_pin_cfg(pdata, &pdev->dev, &num_rows))
+		return -EINVAL;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "failed to get I/O memory\n");
+		return -ENXIO;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "failed to get keyboard IRQ\n");
+		return -ENXIO;
+	}
+
+	kbc = kzalloc(sizeof(*kbc), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!kbc || !input_dev) {
+		err = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	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 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 err_free_mem_region;
+	}
+
+	kbc->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(kbc->clk)) {
+		dev_err(&pdev->dev, "failed to get keyboard clock\n");
+		err = PTR_ERR(kbc->clk);
+		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
+	 * 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;
+
+	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;
+
+	input_set_drvdata(input_dev, kbc);
+
+	input_dev->evbit[0] = BIT_MASK(EV_KEY);
+	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
+
+	input_dev->keycode = kbc->keycode;
+	input_dev->keycodesize = sizeof(kbc->keycode[0]);
+	input_dev->keycodemax = ARRAY_SIZE(kbc->keycode);
+
+	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);
+
+	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 err_put_clk;
+	}
+
+	disable_irq(kbc->irq);
+
+	err = input_register_device(kbc->idev);
+	if (err) {
+		dev_err(&pdev->dev, "failed to register input device\n");
+		goto err_free_irq;
+	}
+
+	platform_set_drvdata(pdev, kbc);
+	device_init_wakeup(&pdev->dev, pdata->wakeup);
+
+	return 0;
+
+err_free_irq:
+	free_irq(kbc->irq, pdev);
+err_put_clk:
+	clk_put(kbc->clk);
+err_iounmap:
+	iounmap(kbc->mmio);
+err_free_mem_region:
+	release_mem_region(res->start, resource_size(res));
+err_free_mem:
+	input_free_device(kbc->idev);
+	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_SLEEP
+static int tegra_kbc_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct tegra_kbc *kbc = platform_get_drvdata(pdev);
+
+	if (device_may_wakeup(&pdev->dev)) {
+		tegra_kbc_setup_wakekeys(kbc, true);
+		enable_irq_wake(kbc->irq);
+		/* Forcefully clear the interrupt status */
+		writel(0x7, kbc->mmio + KBC_INT_0);
+		msleep(30);
+	} else {
+		mutex_lock(&kbc->idev->mutex);
+		if (kbc->idev->users)
+			tegra_kbc_stop(kbc);
+		mutex_unlock(&kbc->idev->mutex);
+	}
+
+	return 0;
+}
+
+static int tegra_kbc_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct tegra_kbc *kbc = platform_get_drvdata(pdev);
+	int err = 0;
+
+	if (device_may_wakeup(&pdev->dev)) {
+		disable_irq_wake(kbc->irq);
+		tegra_kbc_setup_wakekeys(kbc, false);
+	} else {
+		mutex_lock(&kbc->idev->mutex);
+		if (kbc->idev->users)
+			err = tegra_kbc_start(kbc);
+		mutex_unlock(&kbc->idev->mutex);
+	}
+
+	return err;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(tegra_kbc_pm_ops, tegra_kbc_suspend, tegra_kbc_resume);
+
+static struct platform_driver tegra_kbc_driver = {
+	.probe		= tegra_kbc_probe,
+	.remove		= __devexit_p(tegra_kbc_remove),
+	.driver	= {
+		.name	= "tegra-kbc",
+		.owner  = THIS_MODULE,
+		.pm	= &tegra_kbc_pm_ops,
+	},
+};
+
+static void __exit tegra_kbc_exit(void)
+{
+	platform_driver_unregister(&tegra_kbc_driver);
+}
+module_exit(tegra_kbc_exit);
+
+static int __init tegra_kbc_init(void)
+{
+	return platform_driver_register(&tegra_kbc_driver);
+}
+module_init(tegra_kbc_init);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Rakesh Iyer <riyer@nvidia.com>");
+MODULE_DESCRIPTION("Tegra matrix keyboard controller driver");
+MODULE_ALIAS("platform:tegra-kbc");