rtc-da9052.c

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/*
 * Real time clock driver for DA9052
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: Dajun Dajun Chen <[email protected]>
 *
 * 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.
 *
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>

#include <linux/mfd/da9052/da9052.h>
#include <linux/mfd/da9052/reg.h>

#define rtc_err(da9052, fmt, ...) \
        dev_err(da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)

struct da9052_rtc {
    struct rtc_device *rtc;
    struct da9052 *da9052;
    int irq;
};

static int da9052_rtc_enable_alarm(struct da9052 *da9052, bool enable)
{
    int ret;
    if (enable) {
        ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
                    DA9052_ALARM_Y_ALARM_ON,
                    DA9052_ALARM_Y_ALARM_ON);
        if (ret != 0)
            rtc_err(da9052, "Failed to enable ALM: %d\n", ret);
    } else {
        ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
                    DA9052_ALARM_Y_ALARM_ON, 0);
        if (ret != 0)
            rtc_err(da9052, "Write error: %d\n", ret);
    }
    return ret;
}

static irqreturn_t da9052_rtc_irq(int irq, void *data)
{
    struct da9052_rtc *rtc = data;
    int ret;

    ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_MI_REG);
    if (ret < 0) {
        rtc_err(rtc->da9052, "Read error: %d\n", ret);
        return IRQ_NONE;
    }

    if (ret & DA9052_ALARMMI_ALARMTYPE) {
        da9052_rtc_enable_alarm(rtc->da9052, 0);
        rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
    } else
        rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_PF);

    return IRQ_HANDLED;
}

static int da9052_read_alarm(struct da9052 *da9052, struct rtc_time *rtc_tm)
{
    int ret;
    uint8_t v[5];

    ret = da9052_group_read(da9052, DA9052_ALARM_MI_REG, 5, v);
    if (ret != 0) {
        rtc_err(da9052, "Failed to group read ALM: %d\n", ret);
        return ret;
    }

    rtc_tm->tm_year = (v[4] & DA9052_RTC_YEAR) + 100;
    rtc_tm->tm_mon  = (v[3] & DA9052_RTC_MONTH) - 1;
    rtc_tm->tm_mday = v[2] & DA9052_RTC_DAY;
    rtc_tm->tm_hour = v[1] & DA9052_RTC_HOUR;
    rtc_tm->tm_min  = v[0] & DA9052_RTC_MIN;

    ret = rtc_valid_tm(rtc_tm);
    if (ret != 0)
        return ret;
    return ret;
}

static int da9052_set_alarm(struct da9052 *da9052, struct rtc_time *rtc_tm)
{
    int ret;
    uint8_t v[3];

    rtc_tm->tm_year -= 100;
    rtc_tm->tm_mon += 1;

    ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
                DA9052_RTC_MIN, rtc_tm->tm_min);
    if (ret != 0) {
        rtc_err(da9052, "Failed to write ALRM MIN: %d\n", ret);
        return ret;
    }

    v[0] = rtc_tm->tm_hour;
    v[1] = rtc_tm->tm_mday;
    v[2] = rtc_tm->tm_mon;

    ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
    if (ret < 0)
        return ret;

    ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
                DA9052_RTC_YEAR, rtc_tm->tm_year);
    if (ret != 0)
        rtc_err(da9052, "Failed to write ALRM YEAR: %d\n", ret);

    return ret;
}

static int da9052_rtc_get_alarm_status(struct da9052 *da9052)
{
    int ret;

    ret = da9052_reg_read(da9052, DA9052_ALARM_Y_REG);
    if (ret < 0) {
        rtc_err(da9052, "Failed to read ALM: %d\n", ret);
        return ret;
    }
    ret &= DA9052_ALARM_Y_ALARM_ON;
    return (ret > 0) ? 1 : 0;
}

static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
{
    struct da9052_rtc *rtc = dev_get_drvdata(dev);
    uint8_t v[6];
    int ret;

    ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
    if (ret < 0) {
        rtc_err(rtc->da9052, "Failed to read RTC time : %d\n", ret);
        return ret;
    }

    rtc_tm->tm_year = (v[5] & DA9052_RTC_YEAR) + 100;
    rtc_tm->tm_mon  = (v[4] & DA9052_RTC_MONTH) - 1;
    rtc_tm->tm_mday = v[3] & DA9052_RTC_DAY;
    rtc_tm->tm_hour = v[2] & DA9052_RTC_HOUR;
    rtc_tm->tm_min  = v[1] & DA9052_RTC_MIN;
    rtc_tm->tm_sec  = v[0] & DA9052_RTC_SEC;

    ret = rtc_valid_tm(rtc_tm);
    if (ret != 0) {
        rtc_err(rtc->da9052, "rtc_valid_tm failed: %d\n", ret);
        return ret;
    }

    return 0;
}

static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
    struct da9052_rtc *rtc;
    uint8_t v[6];

    rtc = dev_get_drvdata(dev);

    v[0] = tm->tm_sec;
    v[1] = tm->tm_min;
    v[2] = tm->tm_hour;
    v[3] = tm->tm_mday;
    v[4] = tm->tm_mon + 1;
    v[5] = tm->tm_year - 100;

    return da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
}

static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
    int ret;
    struct rtc_time *tm = &alrm->time;
    struct da9052_rtc *rtc = dev_get_drvdata(dev);

    ret = da9052_read_alarm(rtc->da9052, tm);

    if (ret)
        return ret;

    alrm->enabled = da9052_rtc_get_alarm_status(rtc->da9052);

    return 0;
}

static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
    int ret;
    struct rtc_time *tm = &alrm->time;
    struct da9052_rtc *rtc = dev_get_drvdata(dev);

    ret = da9052_rtc_enable_alarm(rtc->da9052, 0);
    if (ret < 0)
        return ret;

    ret = da9052_set_alarm(rtc->da9052, tm);
    if (ret)
        return ret;

    ret = da9052_rtc_enable_alarm(rtc->da9052, 1);

    return ret;
}

static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
    struct da9052_rtc *rtc = dev_get_drvdata(dev);

    return da9052_rtc_enable_alarm(rtc->da9052, enabled);
}

static const struct rtc_class_ops da9052_rtc_ops = {
    .read_time  = da9052_rtc_read_time,
    .set_time   = da9052_rtc_set_time,
    .read_alarm = da9052_rtc_read_alarm,
    .set_alarm  = da9052_rtc_set_alarm,
    .alarm_irq_enable = da9052_rtc_alarm_irq_enable,
};

static int __devinit da9052_rtc_probe(struct platform_device *pdev)
{
    struct da9052_rtc *rtc;
    int ret;

    rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
    if (!rtc)
        return -ENOMEM;

    rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
    platform_set_drvdata(pdev, rtc);
    rtc->irq = platform_get_irq_byname(pdev, "ALM");
    ret = request_threaded_irq(rtc->irq, NULL, da9052_rtc_irq,
                   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                   "ALM", rtc);
    if (ret != 0) {
        rtc_err(rtc->da9052, "irq registration failed: %d\n", ret);
        return ret;
    }

    rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
                       &da9052_rtc_ops, THIS_MODULE);
    if (IS_ERR(rtc->rtc)) {
        ret = PTR_ERR(rtc->rtc);
        goto err_free_irq;
    }

    return 0;

err_free_irq:
    free_irq(rtc->irq, rtc);
    return ret;
}

static int __devexit da9052_rtc_remove(struct platform_device *pdev)
{
    struct da9052_rtc *rtc = pdev->dev.platform_data;

    rtc_device_unregister(rtc->rtc);
    free_irq(rtc->irq, rtc);
    platform_set_drvdata(pdev, NULL);

    return 0;
}

static struct platform_driver da9052_rtc_driver = {
    .probe  = da9052_rtc_probe,
    .remove = __devexit_p(da9052_rtc_remove),
    .driver = {
        .name   = "da9052-rtc",
        .owner  = THIS_MODULE,
    },
};

module_platform_driver(da9052_rtc_driver);

MODULE_AUTHOR("David Dajun Chen <[email protected]>");
MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9052-rtc");