Merge tag 'v3.3.7' into 3.3/master

[zen-stable.git] / drivers / input / keyboard / tegra-kbc.c

/*
 * 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/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/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_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_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

struct tegra_kbc {
        void __iomem *mmio;
        struct input_dev *idev;
        unsigned 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;
        const struct tegra_kbc_platform_data *pdata;
        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;
};

static const u32 tegra_kbc_default_keymap[] __devinitdata = {
        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_LEFTMETA),

        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),

        /* Software Handled Function Keys */
        KEY(20, 0, KEY_KP7),

        KEY(21, 0, KEY_KP9),
        KEY(21, 1, KEY_KP8),
        KEY(21, 2, KEY_KP4),
        KEY(21, 4, KEY_KP1),

        KEY(22, 1, KEY_KPSLASH),
        KEY(22, 2, KEY_KP6),
        KEY(22, 3, KEY_KP5),
        KEY(22, 4, KEY_KP3),
        KEY(22, 5, KEY_KP2),
        KEY(22, 7, KEY_KP0),

        KEY(27, 1, KEY_KPASTERISK),
        KEY(27, 3, KEY_KPMINUS),
        KEY(27, 4, KEY_KPPLUS),
        KEY(27, 5, KEY_KPDOT),

        KEY(28, 5, KEY_VOLUMEUP),

        KEY(29, 3, KEY_HOME),
        KEY(29, 4, KEY_END),
        KEY(29, 5, KEY_BRIGHTNESSDOWN),
        KEY(29, 6, KEY_VOLUMEDOWN),
        KEY(29, 7, KEY_BRIGHTNESSUP),

        KEY(30, 0, KEY_NUMLOCK),
        KEY(30, 1, KEY_SCROLLLOCK),
        KEY(30, 2, KEY_MUTE),

        KEY(31, 4, KEY_HELP),
};

static const
struct matrix_keymap_data tegra_kbc_default_keymap_data __devinitdata = {
        .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;
        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 KBC_MAX_KEY apart from the plain keycodes.
         */
        if (fn_keypress) {
                for (i = 0; i < num_down; i++) {
                        scancodes[i] += KBC_MAX_KEY;
                        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(unsigned long data)
{
        struct tegra_kbc *kbc = (struct tegra_kbc *)data;
        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)
{
        const struct tegra_kbc_platform_data *pdata = kbc->pdata;
        int i;
        unsigned int rst_val;

        /* 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);
}

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_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;

                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 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.
         */
        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(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;
}

#ifdef CONFIG_OF
static struct tegra_kbc_platform_data * __devinit
tegra_kbc_dt_parse_pdata(struct platform_device *pdev)
{
        struct tegra_kbc_platform_data *pdata;
        struct device_node *np = pdev->dev.of_node;

        if (!np)
                return NULL;

        pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return NULL;

        if (!of_property_read_u32(np, "debounce-delay", &prop))
                pdata->debounce_cnt = prop;

        if (!of_property_read_u32(np, "repeat-delay", &prop))
                pdata->repeat_cnt = prop;

        if (of_find_property(np, "needs-ghost-filter", NULL))
                pdata->use_ghost_filter = true;

        if (of_find_property(np, "wakeup-source", NULL))
                pdata->wakeup = true;

        /*
         * All currently known keymaps with device tree support use the same
         * pin_cfg, so set it up here.
         */
        for (i = 0; i < KBC_MAX_ROW; i++) {
                pdata->pin_cfg[i].num = i;
                pdata->pin_cfg[i].is_row = true;
        }

        for (i = 0; i < KBC_MAX_COL; i++) {
                pdata->pin_cfg[KBC_MAX_ROW + i].num = i;
                pdata->pin_cfg[KBC_MAX_ROW + i].is_row = false;
        }

        return pdata;
}
#else
static inline struct tegra_kbc_platform_data *tegra_kbc_dt_parse_pdata(
        struct platform_device *pdev)
{
        return NULL;
}
#endif

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 num_rows = 0;
        unsigned int debounce_cnt;
        unsigned int scan_time_rows;

        if (!pdata)
                pdata = tegra_kbc_dt_parse_pdata(pdev);

        if (!pdata)
                return -EINVAL;

        if (!tegra_kbc_check_pin_cfg(pdata, &pdev->dev, &num_rows)) {
                err = -EINVAL;
                goto err_free_pdata;
        }

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res) {
                dev_err(&pdev->dev, "failed to get I/O memory\n");
                err = -ENXIO;
                goto err_free_pdata;
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                dev_err(&pdev->dev, "failed to get keyboard IRQ\n");
                err = -ENXIO;
                goto err_free_pdata;
        }

        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;
        }

        /*
         * 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 = DIV_ROUND_UP(kbc->repoll_dly, KBC_CYCLE_MS);

        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) | BIT_MASK(EV_REP);
        input_set_capability(input_dev, EV_MSC, MSC_SCAN);

        input_dev->keycode = kbc->keycode;
        input_dev->keycodesize = sizeof(kbc->keycode[0]);
        input_dev->keycodemax = KBC_MAX_KEY;
        if (pdata->use_fn_map)
                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);
        kbc->wakeup_key = pdata->wakeup_key;

        err = request_irq(kbc->irq, tegra_kbc_isr,
                          IRQF_NO_SUSPEND | 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(input_dev);
        kfree(kbc);
err_free_pdata:
        if (!pdev->dev.platform_data)
                kfree(pdata);

        return err;
}

static int __devexit tegra_kbc_remove(struct platform_device *pdev)
{
        struct tegra_kbc *kbc = platform_get_drvdata(pdev);
        struct resource *res;

        platform_set_drvdata(pdev, NULL);

        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));

        /*
         * If we do not have platform data attached to the device we
         * allocated it ourselves and thus need to free it.
         */
        if (!pdev->dev.platform_data)
                kfree(kbc->pdata);

        kfree(kbc);

        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);

        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_irq(kbc->irq);
                enable_irq_wake(kbc->irq);
        } else {
                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;

        mutex_lock(&kbc->idev->mutex);
        if (device_may_wakeup(&pdev->dev)) {
                disable_irq_wake(kbc->irq);
                tegra_kbc_setup_wakekeys(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 (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 const struct of_device_id tegra_kbc_of_match[] = {
        { .compatible = "nvidia,tegra20-kbc", },
        { },
};
MODULE_DEVICE_TABLE(of, tegra_kbc_of_match);

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,
                .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");