rtc-88pm80x.c

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/*
 * Real Time Clock driver for Marvell 88PM80x PMIC
 *
 * Copyright (c) 2012 Marvell International Ltd.
 *  Wenzeng Chen<[email protected]>
 *  Qiao Zhou <[email protected]>
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License. See the file "COPYING" in the main directory of this
 * archive for more details.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/regmap.h>
#include <linux/mfd/core.h>
#include <linux/mfd/88pm80x.h>
#include <linux/rtc.h>

#define PM800_RTC_COUNTER1      (0xD1)
#define PM800_RTC_COUNTER2      (0xD2)
#define PM800_RTC_COUNTER3      (0xD3)
#define PM800_RTC_COUNTER4      (0xD4)
#define PM800_RTC_EXPIRE1_1     (0xD5)
#define PM800_RTC_EXPIRE1_2     (0xD6)
#define PM800_RTC_EXPIRE1_3     (0xD7)
#define PM800_RTC_EXPIRE1_4     (0xD8)
#define PM800_RTC_TRIM1         (0xD9)
#define PM800_RTC_TRIM2         (0xDA)
#define PM800_RTC_TRIM3         (0xDB)
#define PM800_RTC_TRIM4         (0xDC)
#define PM800_RTC_EXPIRE2_1     (0xDD)
#define PM800_RTC_EXPIRE2_2     (0xDE)
#define PM800_RTC_EXPIRE2_3     (0xDF)
#define PM800_RTC_EXPIRE2_4     (0xE0)

#define PM800_POWER_DOWN_LOG1   (0xE5)
#define PM800_POWER_DOWN_LOG2   (0xE6)

struct pm80x_rtc_info {
    struct pm80x_chip *chip;
    struct regmap *map;
    struct rtc_device *rtc_dev;
    struct device *dev;
    struct delayed_work calib_work;

    int irq;
    int vrtc;
};

static irqreturn_t rtc_update_handler(int irq, void *data)
{
    struct pm80x_rtc_info *info = (struct pm80x_rtc_info *)data;
    int mask;

    mask = PM800_ALARM | PM800_ALARM_WAKEUP;
    regmap_update_bits(info->map, PM800_RTC_CONTROL, mask | PM800_ALARM1_EN,
               mask);
    rtc_update_irq(info->rtc_dev, 1, RTC_AF);
    return IRQ_HANDLED;
}

static int pm80x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
    struct pm80x_rtc_info *info = dev_get_drvdata(dev);

    if (enabled)
        regmap_update_bits(info->map, PM800_RTC_CONTROL,
                   PM800_ALARM1_EN, PM800_ALARM1_EN);
    else
        regmap_update_bits(info->map, PM800_RTC_CONTROL,
                   PM800_ALARM1_EN, 0);
    return 0;
}

/*
 * Calculate the next alarm time given the requested alarm time mask
 * and the current time.
 */
static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
                struct rtc_time *alrm)
{
    unsigned long next_time;
    unsigned long now_time;

    next->tm_year = now->tm_year;
    next->tm_mon = now->tm_mon;
    next->tm_mday = now->tm_mday;
    next->tm_hour = alrm->tm_hour;
    next->tm_min = alrm->tm_min;
    next->tm_sec = alrm->tm_sec;

    rtc_tm_to_time(now, &now_time);
    rtc_tm_to_time(next, &next_time);

    if (next_time < now_time) {
        /* Advance one day */
        next_time += 60 * 60 * 24;
        rtc_time_to_tm(next_time, next);
    }
}

static int pm80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
    struct pm80x_rtc_info *info = dev_get_drvdata(dev);
    unsigned char buf[4];
    unsigned long ticks, base, data;
    regmap_raw_read(info->map, PM800_RTC_EXPIRE2_1, buf, 4);
    base = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
    dev_dbg(info->dev, "%x-%x-%x-%x\n", buf[0], buf[1], buf[2], buf[3]);

    /* load 32-bit read-only counter */
    regmap_raw_read(info->map, PM800_RTC_COUNTER1, buf, 4);
    data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
    ticks = base + data;
    dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
        base, data, ticks);
    rtc_time_to_tm(ticks, tm);
    return 0;
}

static int pm80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
    struct pm80x_rtc_info *info = dev_get_drvdata(dev);
    unsigned char buf[4];
    unsigned long ticks, base, data;
    if ((tm->tm_year < 70) || (tm->tm_year > 138)) {
        dev_dbg(info->dev,
            "Set time %d out of range. Please set time between 1970 to 2038.\n",
            1900 + tm->tm_year);
        return -EINVAL;
    }
    rtc_tm_to_time(tm, &ticks);

    /* load 32-bit read-only counter */
    regmap_raw_read(info->map, PM800_RTC_COUNTER1, buf, 4);
    data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
    base = ticks - data;
    dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
        base, data, ticks);
    buf[0] = base & 0xFF;
    buf[1] = (base >> 8) & 0xFF;
    buf[2] = (base >> 16) & 0xFF;
    buf[3] = (base >> 24) & 0xFF;
    regmap_raw_write(info->map, PM800_RTC_EXPIRE2_1, buf, 4);

    return 0;
}

static int pm80x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
    struct pm80x_rtc_info *info = dev_get_drvdata(dev);
    unsigned char buf[4];
    unsigned long ticks, base, data;
    int ret;

    regmap_raw_read(info->map, PM800_RTC_EXPIRE2_1, buf, 4);
    base = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
    dev_dbg(info->dev, "%x-%x-%x-%x\n", buf[0], buf[1], buf[2], buf[3]);

    regmap_raw_read(info->map, PM800_RTC_EXPIRE1_1, buf, 4);
    data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
    ticks = base + data;
    dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
        base, data, ticks);

    rtc_time_to_tm(ticks, &alrm->time);
    regmap_read(info->map, PM800_RTC_CONTROL, &ret);
    alrm->enabled = (ret & PM800_ALARM1_EN) ? 1 : 0;
    alrm->pending = (ret & (PM800_ALARM | PM800_ALARM_WAKEUP)) ? 1 : 0;
    return 0;
}

static int pm80x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
    struct pm80x_rtc_info *info = dev_get_drvdata(dev);
    struct rtc_time now_tm, alarm_tm;
    unsigned long ticks, base, data;
    unsigned char buf[4];
    int mask;

    regmap_update_bits(info->map, PM800_RTC_CONTROL, PM800_ALARM1_EN, 0);

    regmap_raw_read(info->map, PM800_RTC_EXPIRE2_1, buf, 4);
    base = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
    dev_dbg(info->dev, "%x-%x-%x-%x\n", buf[0], buf[1], buf[2], buf[3]);

    /* load 32-bit read-only counter */
    regmap_raw_read(info->map, PM800_RTC_COUNTER1, buf, 4);
    data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
    ticks = base + data;
    dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
        base, data, ticks);

    rtc_time_to_tm(ticks, &now_tm);
    dev_dbg(info->dev, "%s, now time : %lu\n", __func__, ticks);
    rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time);
    /* get new ticks for alarm in 24 hours */
    rtc_tm_to_time(&alarm_tm, &ticks);
    dev_dbg(info->dev, "%s, alarm time: %lu\n", __func__, ticks);
    data = ticks - base;

    buf[0] = data & 0xff;
    buf[1] = (data >> 8) & 0xff;
    buf[2] = (data >> 16) & 0xff;
    buf[3] = (data >> 24) & 0xff;
    regmap_raw_write(info->map, PM800_RTC_EXPIRE1_1, buf, 4);
    if (alrm->enabled) {
        mask = PM800_ALARM | PM800_ALARM_WAKEUP | PM800_ALARM1_EN;
        regmap_update_bits(info->map, PM800_RTC_CONTROL, mask, mask);
    } else {
        mask = PM800_ALARM | PM800_ALARM_WAKEUP | PM800_ALARM1_EN;
        regmap_update_bits(info->map, PM800_RTC_CONTROL, mask,
                   PM800_ALARM | PM800_ALARM_WAKEUP);
    }
    return 0;
}

static const struct rtc_class_ops pm80x_rtc_ops = {
    .read_time = pm80x_rtc_read_time,
    .set_time = pm80x_rtc_set_time,
    .read_alarm = pm80x_rtc_read_alarm,
    .set_alarm = pm80x_rtc_set_alarm,
    .alarm_irq_enable = pm80x_rtc_alarm_irq_enable,
};

#ifdef CONFIG_PM
static int pm80x_rtc_suspend(struct device *dev)
{
    return pm80x_dev_suspend(dev);
}

static int pm80x_rtc_resume(struct device *dev)
{
    return pm80x_dev_resume(dev);
}
#endif

static SIMPLE_DEV_PM_OPS(pm80x_rtc_pm_ops, pm80x_rtc_suspend, pm80x_rtc_resume);

static int __devinit pm80x_rtc_probe(struct platform_device *pdev)
{
    struct pm80x_chip *chip = dev_get_drvdata(pdev->dev.parent);
    struct pm80x_platform_data *pm80x_pdata;
    struct pm80x_rtc_pdata *pdata = NULL;
    struct pm80x_rtc_info *info;
    struct rtc_time tm;
    unsigned long ticks = 0;
    int ret;

    pdata = pdev->dev.platform_data;
    if (pdata == NULL)
        dev_warn(&pdev->dev, "No platform data!\n");

    info =
        devm_kzalloc(&pdev->dev, sizeof(struct pm80x_rtc_info), GFP_KERNEL);
    if (!info)
        return -ENOMEM;
    info->irq = platform_get_irq(pdev, 0);
    if (info->irq < 0) {
        dev_err(&pdev->dev, "No IRQ resource!\n");
        ret = -EINVAL;
        goto out;
    }

    info->chip = chip;
    info->map = chip->regmap;
    if (!info->map) {
        dev_err(&pdev->dev, "no regmap!\n");
        ret = -EINVAL;
        goto out;
    }

    info->dev = &pdev->dev;
    dev_set_drvdata(&pdev->dev, info);

    ret = pm80x_request_irq(chip, info->irq, rtc_update_handler,
                IRQF_ONESHOT, "rtc", info);
    if (ret < 0) {
        dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
            info->irq, ret);
        goto out;
    }

    ret = pm80x_rtc_read_time(&pdev->dev, &tm);
    if (ret < 0) {
        dev_err(&pdev->dev, "Failed to read initial time.\n");
        goto out_rtc;
    }
    if ((tm.tm_year < 70) || (tm.tm_year > 138)) {
        tm.tm_year = 70;
        tm.tm_mon = 0;
        tm.tm_mday = 1;
        tm.tm_hour = 0;
        tm.tm_min = 0;
        tm.tm_sec = 0;
        ret = pm80x_rtc_set_time(&pdev->dev, &tm);
        if (ret < 0) {
            dev_err(&pdev->dev, "Failed to set initial time.\n");
            goto out_rtc;
        }
    }
    rtc_tm_to_time(&tm, &ticks);

    info->rtc_dev = rtc_device_register("88pm80x-rtc", &pdev->dev,
                        &pm80x_rtc_ops, THIS_MODULE);
    if (IS_ERR(info->rtc_dev)) {
        ret = PTR_ERR(info->rtc_dev);
        dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
        goto out_rtc;
    }
    /*
     * enable internal XO instead of internal 3.25MHz clock since it can
     * free running in PMIC power-down state.
     */
    regmap_update_bits(info->map, PM800_RTC_CONTROL, PM800_RTC1_USE_XO,
               PM800_RTC1_USE_XO);

    if (pdev->dev.parent->platform_data) {
        pm80x_pdata = pdev->dev.parent->platform_data;
        pdata = pm80x_pdata->rtc;
        if (pdata)
            info->rtc_dev->dev.platform_data = &pdata->rtc_wakeup;
    }

    device_init_wakeup(&pdev->dev, 1);

    return 0;
out_rtc:
    pm80x_free_irq(chip, info->irq, info);
out:
    return ret;
}

static int __devexit pm80x_rtc_remove(struct platform_device *pdev)
{
    struct pm80x_rtc_info *info = platform_get_drvdata(pdev);
    platform_set_drvdata(pdev, NULL);
    rtc_device_unregister(info->rtc_dev);
    pm80x_free_irq(info->chip, info->irq, info);
    return 0;
}

static struct platform_driver pm80x_rtc_driver = {
    .driver = {
           .name = "88pm80x-rtc",
           .owner = THIS_MODULE,
           .pm = &pm80x_rtc_pm_ops,
           },
    .probe = pm80x_rtc_probe,
    .remove = __devexit_p(pm80x_rtc_remove),
};

module_platform_driver(pm80x_rtc_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Marvell 88PM80x RTC driver");
MODULE_AUTHOR("Qiao Zhou <[email protected]>");
MODULE_ALIAS("platform:88pm80x-rtc");