/*
 * Keypad driver for Analog Devices ADP5520 MFD PMICs
 *
 * Copyright 2009 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/mfd/adp5520.h>
#include <linux/slab.h>
#include <linux/device.h>

struct adp5520_keys {
        struct input_dev *input;
        struct notifier_block notifier;
        struct device *master;
        unsigned short keycode[ADP5520_KEYMAPSIZE];
};

static void adp5520_keys_report_event(struct adp5520_keys *dev,
                                        unsigned short keymask, int value)
{
        int i;

        for (i = 0; i < ADP5520_MAXKEYS; i++)
                if (keymask & (1 << i))
                        input_report_key(dev->input, dev->keycode[i], value);

        input_sync(dev->input);
}

static int adp5520_keys_notifier(struct notifier_block *nb,
                                 unsigned long event, void *data)
{
        struct adp5520_keys *dev;
        uint8_t reg_val_lo, reg_val_hi;
        unsigned short keymask;

        dev = container_of(nb, struct adp5520_keys, notifier);

        if (event & ADP5520_KP_INT) {
                adp5520_read(dev->master, ADP5520_KP_INT_STAT_1, &reg_val_lo);
                adp5520_read(dev->master, ADP5520_KP_INT_STAT_2, &reg_val_hi);

                keymask = (reg_val_hi << 8) | reg_val_lo;
                /* Read twice to clear */
                adp5520_read(dev->master, ADP5520_KP_INT_STAT_1, &reg_val_lo);
                adp5520_read(dev->master, ADP5520_KP_INT_STAT_2, &reg_val_hi);
                keymask |= (reg_val_hi << 8) | reg_val_lo;
                adp5520_keys_report_event(dev, keymask, 1);
        }

        if (event & ADP5520_KR_INT) {
                adp5520_read(dev->master, ADP5520_KR_INT_STAT_1, &reg_val_lo);
                adp5520_read(dev->master, ADP5520_KR_INT_STAT_2, &reg_val_hi);

                keymask = (reg_val_hi << 8) | reg_val_lo;
                /* Read twice to clear */
                adp5520_read(dev->master, ADP5520_KR_INT_STAT_1, &reg_val_lo);
                adp5520_read(dev->master, ADP5520_KR_INT_STAT_2, &reg_val_hi);
                keymask |= (reg_val_hi << 8) | reg_val_lo;
                adp5520_keys_report_event(dev, keymask, 0);
        }

        return 0;
}

static int adp5520_keys_probe(struct platform_device *pdev)
{
        struct adp5520_keys_platform_data *pdata = dev_get_platdata(&pdev->dev);
        struct input_dev *input;
        struct adp5520_keys *dev;
        int ret, i;
        unsigned char en_mask, ctl_mask = 0;

        if (pdev->id != ID_ADP5520) {
                dev_err(&pdev->dev, "only ADP5520 supports Keypad\n");
                return -EINVAL;
        }

        if (!pdata) {
                dev_err(&pdev->dev, "missing platform data\n");
                return -EINVAL;
        }

        if (!(pdata->rows_en_mask && pdata->cols_en_mask))
                return -EINVAL;

        dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
        if (!dev) {
                dev_err(&pdev->dev, "failed to alloc memory\n");
                return -ENOMEM;
        }

        input = devm_input_allocate_device(&pdev->dev);
        if (!input)
                return -ENOMEM;

        dev->master = pdev->dev.parent;
        dev->input = input;

        input->name = pdev->name;
        input->phys = "adp5520-keys/input0";
        input->dev.parent = &pdev->dev;

        input_set_drvdata(input, dev);

        input->id.bustype = BUS_I2C;
        input->id.vendor = 0x0001;
        input->id.product = 0x5520;
        input->id.version = 0x0001;

        input->keycodesize = sizeof(dev->keycode[0]);
        input->keycodemax = pdata->keymapsize;
        input->keycode = dev->keycode;

        memcpy(dev->keycode, pdata->keymap,
                pdata->keymapsize * input->keycodesize);

        /* setup input device */
        __set_bit(EV_KEY, input->evbit);

        if (pdata->repeat)
                __set_bit(EV_REP, input->evbit);

        for (i = 0; i < input->keycodemax; i++)
                __set_bit(dev->keycode[i], input->keybit);
        __clear_bit(KEY_RESERVED, input->keybit);

        ret = input_register_device(input);
        if (ret) {
                dev_err(&pdev->dev, "unable to register input device\n");
                return ret;
        }

        en_mask = pdata->rows_en_mask | pdata->cols_en_mask;

        ret = adp5520_set_bits(dev->master, ADP5520_GPIO_CFG_1, en_mask);

        if (en_mask & ADP5520_COL_C3)
                ctl_mask |= ADP5520_C3_MODE;

        if (en_mask & ADP5520_ROW_R3)
                ctl_mask |= ADP5520_R3_MODE;

        if (ctl_mask)
                ret |= adp5520_set_bits(dev->master, ADP5520_LED_CONTROL,
                        ctl_mask);

        ret |= adp5520_set_bits(dev->master, ADP5520_GPIO_PULLUP,
                pdata->rows_en_mask);

        if (ret) {
                dev_err(&pdev->dev, "failed to write\n");
                return -EIO;
        }

        dev->notifier.notifier_call = adp5520_keys_notifier;
        ret = adp5520_register_notifier(dev->master, &dev->notifier,
                        ADP5520_KP_IEN | ADP5520_KR_IEN);
        if (ret) {
                dev_err(&pdev->dev, "failed to register notifier\n");
                return ret;
        }

        platform_set_drvdata(pdev, dev);
        return 0;
}

static int adp5520_keys_remove(struct platform_device *pdev)
{
        struct adp5520_keys *dev = platform_get_drvdata(pdev);

        adp5520_unregister_notifier(dev->master, &dev->notifier,
                                ADP5520_KP_IEN | ADP5520_KR_IEN);

        return 0;
}

static struct platform_driver adp5520_keys_driver = {
        .driver = {
                .name   = "adp5520-keys",
                .owner  = THIS_MODULE,
        },
        .probe          = adp5520_keys_probe,
        .remove         = adp5520_keys_remove,
};
module_platform_driver(adp5520_keys_driver);

MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Keys ADP5520 Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:adp5520-keys");