Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 822 insertions, 0 deletions

diff --git a/drivers/input/keyboard/tegra-kbc.c b/drivers/input/keyboard/tegra-kbc.c
new file mode 100644
index 000000000..570fe18c0
--- /dev/null
+++ b/drivers/input/keyboard/tegra-kbc.c
@@ -0,0 +1,822 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Keyboard class input driver for the NVIDIA Tegra SoC internal matrix
+ * keyboard controller
+ *
+ * Copyright (c) 2009-2011, NVIDIA Corporation.
+ */
+
+#include <linux/kernel.h>
+#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/of.h>
+#include <linux/of_device.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/reset.h>
+#include <linux/err.h>
+
+#define KBC_MAX_KPENT	8
+
+/* Maximum row/column supported by Tegra KBC yet  is 16x8 */
+#define KBC_MAX_GPIO	24
+/* Maximum keys supported by Tegra KBC yet is 16 x 8*/
+#define KBC_MAX_KEY	(16 * 8)
+
+#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_MS	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_KEYPRESS_INT_EN	(1 << 1)
+#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_INT_KEYPRESS_INT_STATUS	(1 << 0)
+
+#define KBC_ROW_CFG0_0	0x8
+#define KBC_COL_CFG0_0	0x18
+#define KBC_TO_CNT_0	0x24
+#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
+
+enum tegra_pin_type {
+	PIN_CFG_IGNORE,
+	PIN_CFG_COL,
+	PIN_CFG_ROW,
+};
+
+/* Tegra KBC hw support */
+struct tegra_kbc_hw_support {
+	int max_rows;
+	int max_columns;
+};
+
+struct tegra_kbc_pin_cfg {
+	enum tegra_pin_type type;
+	unsigned char num;
+};
+
+struct tegra_kbc {
+	struct device *dev;
+	unsigned int debounce_cnt;
+	unsigned int repeat_cnt;
+	struct tegra_kbc_pin_cfg pin_cfg[KBC_MAX_GPIO];
+	const struct matrix_keymap_data *keymap_data;
+	bool wakeup;
+	void __iomem *mmio;
+	struct input_dev *idev;
+	int irq;
+	spinlock_t lock;
+	unsigned int repoll_dly;
+	unsigned long cp_dly_jiffies;
+	unsigned int cp_to_wkup_dly;
+	bool use_fn_map;
+	bool use_ghost_filter;
+	bool keypress_caused_wake;
+	unsigned short keycode[KBC_MAX_KEY * 2];
+	unsigned short current_keys[KBC_MAX_KPENT];
+	unsigned int num_pressed_keys;
+	u32 wakeup_key;
+	struct timer_list timer;
+	struct clk *clk;
+	struct reset_control *rst;
+	const struct tegra_kbc_hw_support *hw_support;
+	int max_keys;
+	int num_rows_and_columns;
+};
+
+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;
+	bool fn_keypress = false;
+	bool key_in_same_row = false;
+	bool key_in_same_col = false;
+
+	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];
+			/* If driver uses Fn map, do not report the Fn key. */
+			if ((keycodes[num_down] == KEY_FN) && kbc->use_fn_map)
+				fn_keypress = true;
+			else
+				num_down++;
+		}
+
+		val >>= 8;
+	}
+
+	/*
+	 * 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 max_keys apart from the plain keycodes.
+	 */
+	if (fn_keypress) {
+		for (i = 0; i < num_down; i++) {
+			scancodes[i] += kbc->max_keys;
+			keycodes[i] = kbc->keycode[scancodes[i]];
+		}
+	}
+
+	/* 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);
+	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_set_fifo_interrupt(struct tegra_kbc *kbc, bool enable)
+{
+	u32 val;
+
+	val = readl(kbc->mmio + KBC_CONTROL_0);
+	if (enable)
+		val |= KBC_CONTROL_FIFO_CNT_INT_EN;
+	else
+		val &= ~KBC_CONTROL_FIFO_CNT_INT_EN;
+	writel(val, kbc->mmio + KBC_CONTROL_0);
+}
+
+static void tegra_kbc_keypress_timer(struct timer_list *t)
+{
+	struct tegra_kbc *kbc = from_timer(kbc, t, timer);
+	unsigned long flags;
+	u32 val;
+	unsigned int i;
+
+	spin_lock_irqsave(&kbc->lock, flags);
+
+	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 */
+		tegra_kbc_set_fifo_interrupt(kbc, true);
+	}
+
+	spin_unlock_irqrestore(&kbc->lock, flags);
+}
+
+static irqreturn_t tegra_kbc_isr(int irq, void *args)
+{
+	struct tegra_kbc *kbc = args;
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&kbc->lock, flags);
+
+	/*
+	 * 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) {
+		/*
+		 * Until all keys are released, defer further processing to
+		 * the polling loop in tegra_kbc_keypress_timer.
+		 */
+		tegra_kbc_set_fifo_interrupt(kbc, false);
+		mod_timer(&kbc->timer, jiffies + kbc->cp_dly_jiffies);
+	} else if (val & KBC_INT_KEYPRESS_INT_STATUS) {
+		/* We can be here only through system resume path */
+		kbc->keypress_caused_wake = true;
+	}
+
+	spin_unlock_irqrestore(&kbc->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static void tegra_kbc_setup_wakekeys(struct tegra_kbc *kbc, bool filter)
+{
+	int i;
+	unsigned int rst_val;
+
+	/* Either mask all keys or none. */
+	rst_val = (filter && !kbc->wakeup) ? ~0 : 0;
+
+	for (i = 0; i < kbc->hw_support->max_rows; i++)
+		writel(rst_val, kbc->mmio + KBC_ROW0_MASK_0 + i * 4);
+}
+
+static void tegra_kbc_config_pins(struct tegra_kbc *kbc)
+{
+	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_shft;
+		u32 c_mask = 0x0f << c_shft;
+		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;
+
+		switch (kbc->pin_cfg[i].type) {
+		case PIN_CFG_ROW:
+			row_cfg |= ((kbc->pin_cfg[i].num << 1) | 1) << r_shft;
+			break;
+
+		case PIN_CFG_COL:
+			col_cfg |= ((kbc->pin_cfg[i].num << 1) | 1) << c_shft;
+			break;
+
+		case PIN_CFG_IGNORE:
+			break;
+		}
+
+		writel(row_cfg, kbc->mmio + r_offs);
+		writel(col_cfg, kbc->mmio + c_offs);
+	}
+}
+
+static int tegra_kbc_start(struct tegra_kbc *kbc)
+{
+	unsigned int debounce_cnt;
+	u32 val = 0;
+	int ret;
+
+	ret = clk_prepare_enable(kbc->clk);
+	if (ret)
+		return ret;
+
+	/* Reset the KBC controller to clear all previous status.*/
+	reset_control_assert(kbc->rst);
+	udelay(100);
+	reset_control_deassert(kbc->rst);
+	udelay(100);
+
+	tegra_kbc_config_pins(kbc);
+	tegra_kbc_setup_wakekeys(kbc, false);
+
+	writel(kbc->repeat_cnt, kbc->mmio + KBC_RPT_DLY_0);
+
+	/* Keyboard debounce count is maximum of 12 bits. */
+	debounce_cnt = min(kbc->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.
+	 */
+	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);
+
+	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_unprepare(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 tegra_kbc_check_pin_cfg(const struct tegra_kbc *kbc,
+					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 = &kbc->pin_cfg[i];
+
+		switch (pin_cfg->type) {
+		case PIN_CFG_ROW:
+			if (pin_cfg->num >= kbc->hw_support->max_rows) {
+				dev_err(kbc->dev,
+					"pin_cfg[%d]: invalid row number %d\n",
+					i, pin_cfg->num);
+				return false;
+			}
+			(*num_rows)++;
+			break;
+
+		case PIN_CFG_COL:
+			if (pin_cfg->num >= kbc->hw_support->max_columns) {
+				dev_err(kbc->dev,
+					"pin_cfg[%d]: invalid column number %d\n",
+					i, pin_cfg->num);
+				return false;
+			}
+			break;
+
+		case PIN_CFG_IGNORE:
+			break;
+
+		default:
+			dev_err(kbc->dev,
+				"pin_cfg[%d]: invalid entry type %d\n",
+				pin_cfg->type, pin_cfg->num);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static int tegra_kbc_parse_dt(struct tegra_kbc *kbc)
+{
+	struct device_node *np = kbc->dev->of_node;
+	u32 prop;
+	int i;
+	u32 num_rows = 0;
+	u32 num_cols = 0;
+	u32 cols_cfg[KBC_MAX_GPIO];
+	u32 rows_cfg[KBC_MAX_GPIO];
+	int proplen;
+	int ret;
+
+	if (!of_property_read_u32(np, "nvidia,debounce-delay-ms", &prop))
+		kbc->debounce_cnt = prop;
+
+	if (!of_property_read_u32(np, "nvidia,repeat-delay-ms", &prop))
+		kbc->repeat_cnt = prop;
+
+	if (of_find_property(np, "nvidia,needs-ghost-filter", NULL))
+		kbc->use_ghost_filter = true;
+
+	if (of_property_read_bool(np, "wakeup-source") ||
+	    of_property_read_bool(np, "nvidia,wakeup-source")) /* legacy */
+		kbc->wakeup = true;
+
+	if (!of_get_property(np, "nvidia,kbc-row-pins", &proplen)) {
+		dev_err(kbc->dev, "property nvidia,kbc-row-pins not found\n");
+		return -ENOENT;
+	}
+	num_rows = proplen / sizeof(u32);
+
+	if (!of_get_property(np, "nvidia,kbc-col-pins", &proplen)) {
+		dev_err(kbc->dev, "property nvidia,kbc-col-pins not found\n");
+		return -ENOENT;
+	}
+	num_cols = proplen / sizeof(u32);
+
+	if (num_rows > kbc->hw_support->max_rows) {
+		dev_err(kbc->dev,
+			"Number of rows is more than supported by hardware\n");
+		return -EINVAL;
+	}
+
+	if (num_cols > kbc->hw_support->max_columns) {
+		dev_err(kbc->dev,
+			"Number of cols is more than supported by hardware\n");
+		return -EINVAL;
+	}
+
+	if (!of_get_property(np, "linux,keymap", &proplen)) {
+		dev_err(kbc->dev, "property linux,keymap not found\n");
+		return -ENOENT;
+	}
+
+	if (!num_rows || !num_cols || ((num_rows + num_cols) > KBC_MAX_GPIO)) {
+		dev_err(kbc->dev,
+			"keypad rows/columns not properly specified\n");
+		return -EINVAL;
+	}
+
+	/* Set all pins as non-configured */
+	for (i = 0; i < kbc->num_rows_and_columns; i++)
+		kbc->pin_cfg[i].type = PIN_CFG_IGNORE;
+
+	ret = of_property_read_u32_array(np, "nvidia,kbc-row-pins",
+				rows_cfg, num_rows);
+	if (ret < 0) {
+		dev_err(kbc->dev, "Rows configurations are not proper\n");
+		return -EINVAL;
+	}
+
+	ret = of_property_read_u32_array(np, "nvidia,kbc-col-pins",
+				cols_cfg, num_cols);
+	if (ret < 0) {
+		dev_err(kbc->dev, "Cols configurations are not proper\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < num_rows; i++) {
+		kbc->pin_cfg[rows_cfg[i]].type = PIN_CFG_ROW;
+		kbc->pin_cfg[rows_cfg[i]].num = i;
+	}
+
+	for (i = 0; i < num_cols; i++) {
+		kbc->pin_cfg[cols_cfg[i]].type = PIN_CFG_COL;
+		kbc->pin_cfg[cols_cfg[i]].num = i;
+	}
+
+	return 0;
+}
+
+static const struct tegra_kbc_hw_support tegra20_kbc_hw_support = {
+	.max_rows	= 16,
+	.max_columns	= 8,
+};
+
+static const struct tegra_kbc_hw_support tegra11_kbc_hw_support = {
+	.max_rows	= 11,
+	.max_columns	= 8,
+};
+
+static const struct of_device_id tegra_kbc_of_match[] = {
+	{ .compatible = "nvidia,tegra114-kbc", .data = &tegra11_kbc_hw_support},
+	{ .compatible = "nvidia,tegra30-kbc", .data = &tegra20_kbc_hw_support},
+	{ .compatible = "nvidia,tegra20-kbc", .data = &tegra20_kbc_hw_support},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tegra_kbc_of_match);
+
+static int tegra_kbc_probe(struct platform_device *pdev)
+{
+	struct tegra_kbc *kbc;
+	struct resource *res;
+	int err;
+	int num_rows = 0;
+	unsigned int debounce_cnt;
+	unsigned int scan_time_rows;
+	unsigned int keymap_rows;
+	const struct of_device_id *match;
+
+	match = of_match_device(tegra_kbc_of_match, &pdev->dev);
+
+	kbc = devm_kzalloc(&pdev->dev, sizeof(*kbc), GFP_KERNEL);
+	if (!kbc) {
+		dev_err(&pdev->dev, "failed to alloc memory for kbc\n");
+		return -ENOMEM;
+	}
+
+	kbc->dev = &pdev->dev;
+	kbc->hw_support = match->data;
+	kbc->max_keys = kbc->hw_support->max_rows *
+				kbc->hw_support->max_columns;
+	kbc->num_rows_and_columns = kbc->hw_support->max_rows +
+					kbc->hw_support->max_columns;
+	keymap_rows = kbc->max_keys;
+	spin_lock_init(&kbc->lock);
+
+	err = tegra_kbc_parse_dt(kbc);
+	if (err)
+		return err;
+
+	if (!tegra_kbc_check_pin_cfg(kbc, &num_rows))
+		return -EINVAL;
+
+	kbc->irq = platform_get_irq(pdev, 0);
+	if (kbc->irq < 0)
+		return -ENXIO;
+
+	kbc->idev = devm_input_allocate_device(&pdev->dev);
+	if (!kbc->idev) {
+		dev_err(&pdev->dev, "failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	timer_setup(&kbc->timer, tegra_kbc_keypress_timer, 0);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	kbc->mmio = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(kbc->mmio))
+		return PTR_ERR(kbc->mmio);
+
+	kbc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(kbc->clk)) {
+		dev_err(&pdev->dev, "failed to get keyboard clock\n");
+		return PTR_ERR(kbc->clk);
+	}
+
+	kbc->rst = devm_reset_control_get(&pdev->dev, "kbc");
+	if (IS_ERR(kbc->rst)) {
+		dev_err(&pdev->dev, "failed to get keyboard reset\n");
+		return PTR_ERR(kbc->rst);
+	}
+
+	/*
+	 * 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(kbc->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 + kbc->repeat_cnt;
+	kbc->repoll_dly = DIV_ROUND_UP(kbc->repoll_dly, KBC_CYCLE_MS);
+
+	kbc->idev->name = pdev->name;
+	kbc->idev->id.bustype = BUS_HOST;
+	kbc->idev->dev.parent = &pdev->dev;
+	kbc->idev->open = tegra_kbc_open;
+	kbc->idev->close = tegra_kbc_close;
+
+	if (kbc->keymap_data && kbc->use_fn_map)
+		keymap_rows *= 2;
+
+	err = matrix_keypad_build_keymap(kbc->keymap_data, NULL,
+					 keymap_rows,
+					 kbc->hw_support->max_columns,
+					 kbc->keycode, kbc->idev);
+	if (err) {
+		dev_err(&pdev->dev, "failed to setup keymap\n");
+		return err;
+	}
+
+	__set_bit(EV_REP, kbc->idev->evbit);
+	input_set_capability(kbc->idev, EV_MSC, MSC_SCAN);
+
+	input_set_drvdata(kbc->idev, kbc);
+
+	err = devm_request_irq(&pdev->dev, kbc->irq, tegra_kbc_isr,
+			       IRQF_TRIGGER_HIGH | IRQF_NO_AUTOEN,
+			       pdev->name, kbc);
+	if (err) {
+		dev_err(&pdev->dev, "failed to request keyboard IRQ\n");
+		return err;
+	}
+
+	err = input_register_device(kbc->idev);
+	if (err) {
+		dev_err(&pdev->dev, "failed to register input device\n");
+		return err;
+	}
+
+	platform_set_drvdata(pdev, kbc);
+	device_init_wakeup(&pdev->dev, kbc->wakeup);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static void tegra_kbc_set_keypress_interrupt(struct tegra_kbc *kbc, bool enable)
+{
+	u32 val;
+
+	val = readl(kbc->mmio + KBC_CONTROL_0);
+	if (enable)
+		val |= KBC_CONTROL_KEYPRESS_INT_EN;
+	else
+		val &= ~KBC_CONTROL_KEYPRESS_INT_EN;
+	writel(val, kbc->mmio + KBC_CONTROL_0);
+}
+
+static int tegra_kbc_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct tegra_kbc *kbc = platform_get_drvdata(pdev);
+
+	mutex_lock(&kbc->idev->mutex);
+	if (device_may_wakeup(&pdev->dev)) {
+		disable_irq(kbc->irq);
+		del_timer_sync(&kbc->timer);
+		tegra_kbc_set_fifo_interrupt(kbc, false);
+
+		/* Forcefully clear the interrupt status */
+		writel(0x7, kbc->mmio + KBC_INT_0);
+		/*
+		 * Store the previous resident time of continuous polling mode.
+		 * Force the keyboard into interrupt mode.
+		 */
+		kbc->cp_to_wkup_dly = readl(kbc->mmio + KBC_TO_CNT_0);
+		writel(0, kbc->mmio + KBC_TO_CNT_0);
+
+		tegra_kbc_setup_wakekeys(kbc, true);
+		msleep(30);
+
+		kbc->keypress_caused_wake = false;
+		/* Enable keypress interrupt before going into suspend. */
+		tegra_kbc_set_keypress_interrupt(kbc, true);
+		enable_irq(kbc->irq);
+		enable_irq_wake(kbc->irq);
+	} else {
+		if (input_device_enabled(kbc->idev))
+			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;
+
+	mutex_lock(&kbc->idev->mutex);
+	if (device_may_wakeup(&pdev->dev)) {
+		disable_irq_wake(kbc->irq);
+		tegra_kbc_setup_wakekeys(kbc, false);
+		/* We will use fifo interrupts for key detection. */
+		tegra_kbc_set_keypress_interrupt(kbc, false);
+
+		/* Restore the resident time of continuous polling mode. */
+		writel(kbc->cp_to_wkup_dly, kbc->mmio + KBC_TO_CNT_0);
+
+		tegra_kbc_set_fifo_interrupt(kbc, true);
+
+		if (kbc->keypress_caused_wake && kbc->wakeup_key) {
+			/*
+			 * We can't report events directly from the ISR
+			 * because timekeeping is stopped when processing
+			 * wakeup request and we get a nasty warning when
+			 * we try to call do_gettimeofday() in evdev
+			 * handler.
+			 */
+			input_report_key(kbc->idev, kbc->wakeup_key, 1);
+			input_sync(kbc->idev);
+			input_report_key(kbc->idev, kbc->wakeup_key, 0);
+			input_sync(kbc->idev);
+		}
+	} else {
+		if (input_device_enabled(kbc->idev))
+			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,
+	.driver	= {
+		.name	= "tegra-kbc",
+		.pm	= &tegra_kbc_pm_ops,
+		.of_match_table = tegra_kbc_of_match,
+	},
+};
+module_platform_driver(tegra_kbc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Rakesh Iyer <riyer@nvidia.com>");
+MODULE_DESCRIPTION("Tegra matrix keyboard controller driver");
+MODULE_ALIAS("platform:tegra-kbc");