tegra-kbc.c

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/*
 * 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 <linux/input/tegra_kbc.h>
#include <mach/clk.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_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

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_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 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;

        switch (pdata->pin_cfg[i].type) {
        case PIN_CFG_ROW:
            row_cfg |= ((pdata->pin_cfg[i].num << 1) | 1) << r_shft;
            break;

        case PIN_CFG_COL:
            col_cfg |= ((pdata->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)
{
    const struct tegra_kbc_platform_data *pdata = kbc->pdata;
    unsigned int debounce_cnt;
    u32 val = 0;

    clk_prepare_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_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 __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];

        switch (pin_cfg->type) {
        case PIN_CFG_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)++;
            break;

        case PIN_CFG_COL:
            if (pin_cfg->num >= KBC_MAX_COL) {
                dev_err(dev,
                    "pin_cfg[%d]: invalid column number %d\n",
                    i, pin_cfg->num);
                return false;
            }
            break;

        case PIN_CFG_IGNORE:
            break;

        default:
            dev_err(dev,
                "pin_cfg[%d]: invalid entry type %d\n",
                pin_cfg->type, 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;
    u32 prop;
    int i;

    if (!np)
        return NULL;

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

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

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

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

    if (of_find_property(np, "nvidia,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].type = PIN_CFG_ROW;
    }

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

    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_kbd_setup_keymap(struct tegra_kbc *kbc)
{
    const struct tegra_kbc_platform_data *pdata = kbc->pdata;
    const struct matrix_keymap_data *keymap_data = pdata->keymap_data;
    unsigned int keymap_rows = KBC_MAX_KEY;
    int retval;

    if (keymap_data && pdata->use_fn_map)
        keymap_rows *= 2;

    retval = matrix_keypad_build_keymap(keymap_data, NULL,
                        keymap_rows, KBC_MAX_COL,
                        kbc->keycode, kbc->idev);
    if (retval == -ENOSYS || retval == -ENOENT) {
        /*
         * If there is no OF support in kernel or keymap
         * property is missing, use default keymap.
         */
        retval = matrix_keypad_build_keymap(
                    &tegra_kbc_default_keymap_data, NULL,
                    keymap_rows, KBC_MAX_COL,
                    kbc->keycode, kbc->idev);
    }

    return retval;
}

static int __devinit tegra_kbc_probe(struct platform_device *pdev)
{
    const struct tegra_kbc_platform_data *pdata = pdev->dev.platform_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);

    kbc->wakeup_key = pdata->wakeup_key;
    kbc->use_fn_map = pdata->use_fn_map;
    kbc->use_ghost_filter = pdata->use_ghost_filter;

    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;

    err = tegra_kbd_setup_keymap(kbc);
    if (err) {
        dev_err(&pdev->dev, "failed to setup keymap\n");
        goto err_put_clk;
    }

    __set_bit(EV_REP, input_dev->evbit);
    input_set_capability(input_dev, EV_MSC, MSC_SCAN);

    input_set_drvdata(input_dev, kbc);

    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 keypress interrupt before going into suspend. */
        tegra_kbc_set_keypress_interrupt(kbc, true);
        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);
        /* 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 (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 <[email protected]>");
MODULE_DESCRIPTION("Tegra matrix keyboard controller driver");
MODULE_ALIAS("platform:tegra-kbc");