tnetv107x-keypad.c

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/*
 * Texas Instruments TNETV107X Keypad Driver
 *
 * Copyright (C) 2010 Texas Instruments
 *
 * 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 version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/input/matrix_keypad.h>
#include <linux/module.h>

#define BITS(x)         (BIT(x) - 1)

#define KEYPAD_ROWS     9
#define KEYPAD_COLS     9

#define DEBOUNCE_MIN        0x400ul
#define DEBOUNCE_MAX        0x3ffffffful

struct keypad_regs {
    u32 rev;
    u32 mode;
    u32 mask;
    u32 pol;
    u32 dclock;
    u32 rclock;
    u32 stable_cnt;
    u32 in_en;
    u32 out;
    u32 out_en;
    u32 in;
    u32 lock;
    u32 pres[3];
};

#define keypad_read(kp, reg)        __raw_readl(&(kp)->regs->reg)
#define keypad_write(kp, reg, val)  __raw_writel(val, &(kp)->regs->reg)

struct keypad_data {
    struct input_dev        *input_dev;
    struct resource         *res;
    struct keypad_regs __iomem  *regs;
    struct clk          *clk;
    struct device           *dev;
    spinlock_t          lock;
    u32             irq_press;
    u32             irq_release;
    int             rows, cols, row_shift;
    int             debounce_ms, active_low;
    u32             prev_keys[3];
    unsigned short          keycodes[];
};

static irqreturn_t keypad_irq(int irq, void *data)
{
    struct keypad_data *kp = data;
    int i, bit, val, row, col, code;
    unsigned long flags;
    u32 curr_keys[3];
    u32 change;

    spin_lock_irqsave(&kp->lock, flags);

    memset(curr_keys, 0, sizeof(curr_keys));
    if (irq == kp->irq_press)
        for (i = 0; i < 3; i++)
            curr_keys[i] = keypad_read(kp, pres[i]);

    for (i = 0; i < 3; i++) {
        change = curr_keys[i] ^ kp->prev_keys[i];

        while (change) {
            bit     = fls(change) - 1;
            change ^= BIT(bit);
            val     = curr_keys[i] & BIT(bit);
            bit    += i * 32;
            row     = bit / KEYPAD_COLS;
            col     = bit % KEYPAD_COLS;

            code = MATRIX_SCAN_CODE(row, col, kp->row_shift);
            input_event(kp->input_dev, EV_MSC, MSC_SCAN, code);
            input_report_key(kp->input_dev, kp->keycodes[code],
                     val);
        }
    }
    input_sync(kp->input_dev);
    memcpy(kp->prev_keys, curr_keys, sizeof(curr_keys));

    if (irq == kp->irq_press)
        keypad_write(kp, lock, 0); /* Allow hardware updates */

    spin_unlock_irqrestore(&kp->lock, flags);

    return IRQ_HANDLED;
}

static int keypad_start(struct input_dev *dev)
{
    struct keypad_data *kp = input_get_drvdata(dev);
    unsigned long mask, debounce, clk_rate_khz;
    unsigned long flags;

    clk_enable(kp->clk);
    clk_rate_khz = clk_get_rate(kp->clk) / 1000;

    spin_lock_irqsave(&kp->lock, flags);

    /* Initialize device registers */
    keypad_write(kp, mode, 0);

    mask  = BITS(kp->rows) << KEYPAD_COLS;
    mask |= BITS(kp->cols);
    keypad_write(kp, mask, ~mask);

    keypad_write(kp, pol, kp->active_low ? 0 : 0x3ffff);
    keypad_write(kp, stable_cnt, 3);

    debounce = kp->debounce_ms * clk_rate_khz;
    debounce = clamp(debounce, DEBOUNCE_MIN, DEBOUNCE_MAX);
    keypad_write(kp, dclock, debounce);
    keypad_write(kp, rclock, 4 * debounce);

    keypad_write(kp, in_en, 1);

    spin_unlock_irqrestore(&kp->lock, flags);

    return 0;
}

static void keypad_stop(struct input_dev *dev)
{
    struct keypad_data *kp = input_get_drvdata(dev);

    synchronize_irq(kp->irq_press);
    synchronize_irq(kp->irq_release);
    clk_disable(kp->clk);
}

static int __devinit keypad_probe(struct platform_device *pdev)
{
    const struct matrix_keypad_platform_data *pdata;
    const struct matrix_keymap_data *keymap_data;
    struct device *dev = &pdev->dev;
    struct keypad_data *kp;
    int error = 0, sz, row_shift;
    u32 rev = 0;

    pdata = pdev->dev.platform_data;
    if (!pdata) {
        dev_err(dev, "cannot find device data\n");
        return -EINVAL;
    }

    keymap_data = pdata->keymap_data;
    if (!keymap_data) {
        dev_err(dev, "cannot find keymap data\n");
        return -EINVAL;
    }

    row_shift = get_count_order(pdata->num_col_gpios);
    sz  = offsetof(struct keypad_data, keycodes);
    sz += (pdata->num_row_gpios << row_shift) * sizeof(kp->keycodes[0]);
    kp = kzalloc(sz, GFP_KERNEL);
    if (!kp) {
        dev_err(dev, "cannot allocate device info\n");
        return -ENOMEM;
    }

    kp->dev  = dev;
    kp->rows = pdata->num_row_gpios;
    kp->cols = pdata->num_col_gpios;
    kp->row_shift = row_shift;
    platform_set_drvdata(pdev, kp);
    spin_lock_init(&kp->lock);

    kp->irq_press   = platform_get_irq_byname(pdev, "press");
    kp->irq_release = platform_get_irq_byname(pdev, "release");
    if (kp->irq_press < 0 || kp->irq_release < 0) {
        dev_err(dev, "cannot determine device interrupts\n");
        error = -ENODEV;
        goto error_res;
    }

    kp->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!kp->res) {
        dev_err(dev, "cannot determine register area\n");
        error = -ENODEV;
        goto error_res;
    }

    if (!request_mem_region(kp->res->start, resource_size(kp->res),
                pdev->name)) {
        dev_err(dev, "cannot claim register memory\n");
        kp->res = NULL;
        error = -EINVAL;
        goto error_res;
    }

    kp->regs = ioremap(kp->res->start, resource_size(kp->res));
    if (!kp->regs) {
        dev_err(dev, "cannot map register memory\n");
        error = -ENOMEM;
        goto error_map;
    }

    kp->clk = clk_get(dev, NULL);
    if (IS_ERR(kp->clk)) {
        dev_err(dev, "cannot claim device clock\n");
        error = PTR_ERR(kp->clk);
        goto error_clk;
    }

    error = request_threaded_irq(kp->irq_press, NULL, keypad_irq,
                     IRQF_ONESHOT, dev_name(dev), kp);
    if (error < 0) {
        dev_err(kp->dev, "Could not allocate keypad press key irq\n");
        goto error_irq_press;
    }

    error = request_threaded_irq(kp->irq_release, NULL, keypad_irq,
                     IRQF_ONESHOT, dev_name(dev), kp);
    if (error < 0) {
        dev_err(kp->dev, "Could not allocate keypad release key irq\n");
        goto error_irq_release;
    }

    kp->input_dev = input_allocate_device();
    if (!kp->input_dev) {
        dev_err(dev, "cannot allocate input device\n");
        error = -ENOMEM;
        goto error_input;
    }

    kp->input_dev->name   = pdev->name;
    kp->input_dev->dev.parent = &pdev->dev;
    kp->input_dev->open   = keypad_start;
    kp->input_dev->close      = keypad_stop;

    clk_enable(kp->clk);
    rev = keypad_read(kp, rev);
    kp->input_dev->id.bustype = BUS_HOST;
    kp->input_dev->id.product = ((rev >>  8) & 0x07);
    kp->input_dev->id.version = ((rev >> 16) & 0xfff);
    clk_disable(kp->clk);

    error = matrix_keypad_build_keymap(keymap_data, NULL,
                       kp->rows, kp->cols,
                       kp->keycodes, kp->input_dev);
    if (error) {
        dev_err(dev, "Failed to build keymap\n");
        goto error_reg;
    }

    if (!pdata->no_autorepeat)
        kp->input_dev->evbit[0] |= BIT_MASK(EV_REP);
    input_set_capability(kp->input_dev, EV_MSC, MSC_SCAN);

    input_set_drvdata(kp->input_dev, kp);

    error = input_register_device(kp->input_dev);
    if (error < 0) {
        dev_err(dev, "Could not register input device\n");
        goto error_reg;
    }

    return 0;


error_reg:
    input_free_device(kp->input_dev);
error_input:
    free_irq(kp->irq_release, kp);
error_irq_release:
    free_irq(kp->irq_press, kp);
error_irq_press:
    clk_put(kp->clk);
error_clk:
    iounmap(kp->regs);
error_map:
    release_mem_region(kp->res->start, resource_size(kp->res));
error_res:
    platform_set_drvdata(pdev, NULL);
    kfree(kp);
    return error;
}

static int __devexit keypad_remove(struct platform_device *pdev)
{
    struct keypad_data *kp = platform_get_drvdata(pdev);

    free_irq(kp->irq_press, kp);
    free_irq(kp->irq_release, kp);
    input_unregister_device(kp->input_dev);
    clk_put(kp->clk);
    iounmap(kp->regs);
    release_mem_region(kp->res->start, resource_size(kp->res));
    platform_set_drvdata(pdev, NULL);
    kfree(kp);

    return 0;
}

static struct platform_driver keypad_driver = {
    .probe      = keypad_probe,
    .remove     = __devexit_p(keypad_remove),
    .driver.name    = "tnetv107x-keypad",
    .driver.owner   = THIS_MODULE,
};
module_platform_driver(keypad_driver);

MODULE_AUTHOR("Cyril Chemparathy");
MODULE_DESCRIPTION("TNETV107X Keypad Driver");
MODULE_ALIAS("platform:tnetv107x-keypad");
MODULE_LICENSE("GPL");