rtc: Enable rtc in max8925

MAX8925 is a PMIC that contains RTC component.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 314 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-max8925.c b/drivers/rtc/rtc-max8925.c
new file mode 100644
index 000000000000..acdbb1760187
--- /dev/null
+++ b/drivers/rtc/rtc-max8925.c
@@ -0,0 +1,314 @@
+/*
+ * RTC driver for Maxim MAX8925
+ *
+ * Copyright (C) 2009-2010 Marvell International Ltd.
+ *      Haojian Zhuang <haojian.zhuang@marvell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/max8925.h>
+
+enum {
+        RTC_SEC = 0,
+        RTC_MIN,
+        RTC_HOUR,
+        RTC_WEEKDAY,
+        RTC_DATE,
+        RTC_MONTH,
+        RTC_YEAR1,
+        RTC_YEAR2,
+};
+
+#define MAX8925_RTC_SEC                 0x00
+#define MAX8925_RTC_MIN                 0x01
+#define MAX8925_RTC_HOUR                0x02
+#define MAX8925_RTC_WEEKDAY             0x03
+#define MAX8925_RTC_DATE                0x04
+#define MAX8925_RTC_MONTH               0x05
+#define MAX8925_RTC_YEAR1               0x06
+#define MAX8925_RTC_YEAR2               0x07
+#define MAX8925_ALARM0_SEC              0x08
+#define MAX8925_ALARM0_MIN              0x09
+#define MAX8925_ALARM0_HOUR             0x0a
+#define MAX8925_ALARM0_WEEKDAY          0x0b
+#define MAX8925_ALARM0_DATE             0x0c
+#define MAX8925_ALARM0_MON              0x0d
+#define MAX8925_ALARM0_YEAR1            0x0e
+#define MAX8925_ALARM0_YEAR2            0x0f
+#define MAX8925_ALARM1_SEC              0x10
+#define MAX8925_ALARM1_MIN              0x11
+#define MAX8925_ALARM1_HOUR             0x12
+#define MAX8925_ALARM1_WEEKDAY          0x13
+#define MAX8925_ALARM1_DATE             0x14
+#define MAX8925_ALARM1_MON              0x15
+#define MAX8925_ALARM1_YEAR1            0x16
+#define MAX8925_ALARM1_YEAR2            0x17
+#define MAX8925_RTC_CNTL                0x1b
+#define MAX8925_RTC_STATUS              0x20
+
+#define TIME_NUM                        8
+#define ALARM_1SEC                      (1 << 7)
+#define HOUR_12                         (1 << 7)
+#define HOUR_AM_PM                      (1 << 5)
+#define ALARM0_IRQ                      (1 << 3)
+#define ALARM1_IRQ                      (1 << 2)
+#define ALARM0_STATUS                   (1 << 2)
+#define ALARM1_STATUS                   (1 << 1)
+
+
+struct max8925_rtc_info {
+        struct rtc_device       *rtc_dev;
+        struct max8925_chip     *chip;
+        struct i2c_client       *rtc;
+        struct device           *dev;
+};
+
+static irqreturn_t rtc_update_handler(int irq, void *data)
+{
+        struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
+
+        /* disable ALARM0 except for 1SEC alarm */
+        max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
+        rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
+        return IRQ_HANDLED;
+}
+
+static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
+{
+        if (len < TIME_NUM)
+                return -EINVAL;
+        tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
+                        + (buf[RTC_YEAR2] & 0xf) * 100
+                        + (buf[RTC_YEAR1] >> 4) * 10
+                        + (buf[RTC_YEAR1] & 0xf);
+        tm->tm_year -= 1900;
+        tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
+                        + (buf[RTC_MONTH] & 0x0f);
+        tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
+                        + (buf[RTC_DATE] & 0x0f);
+        tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
+        if (buf[RTC_HOUR] & HOUR_12) {
+                tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
+                                + (buf[RTC_HOUR] & 0x0f);
+                if (buf[RTC_HOUR] & HOUR_AM_PM)
+                        tm->tm_hour += 12;
+        } else
+                tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
+                                + (buf[RTC_HOUR] & 0x0f);
+        tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
+                        + (buf[RTC_MIN] & 0x0f);
+        tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
+                        + (buf[RTC_SEC] & 0x0f);
+        return 0;
+}
+
+static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
+{
+        unsigned char high, low;
+
+        if (len < TIME_NUM)
+                return -EINVAL;
+
+        high = (tm->tm_year + 1900) / 1000;
+        low = (tm->tm_year + 1900) / 100;
+        low = low - high * 10;
+        buf[RTC_YEAR2] = (high << 4) + low;
+        high = (tm->tm_year + 1900) / 10;
+        low = tm->tm_year + 1900;
+        low = low - high * 10;
+        high = high - (high / 10) * 10;
+        buf[RTC_YEAR1] = (high << 4) + low;
+        high = tm->tm_mon / 10;
+        low = tm->tm_mon;
+        low = low - high * 10;
+        buf[RTC_MONTH] = (high << 4) + low;
+        high = tm->tm_mday / 10;
+        low = tm->tm_mday;
+        low = low - high * 10;
+        buf[RTC_DATE] = (high << 4) + low;
+        buf[RTC_WEEKDAY] = tm->tm_wday;
+        high = tm->tm_hour / 10;
+        low = tm->tm_hour;
+        low = low - high * 10;
+        buf[RTC_HOUR] = (high << 4) + low;
+        high = tm->tm_min / 10;
+        low = tm->tm_min;
+        low = low - high * 10;
+        buf[RTC_MIN] = (high << 4) + low;
+        high = tm->tm_sec / 10;
+        low = tm->tm_sec;
+        low = low - high * 10;
+        buf[RTC_SEC] = (high << 4) + low;
+        return 0;
+}
+
+static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        struct max8925_rtc_info *info = dev_get_drvdata(dev);
+        unsigned char buf[TIME_NUM];
+        int ret;
+
+        ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
+        if (ret < 0)
+                goto out;
+        ret = tm_calc(tm, buf, TIME_NUM);
+out:
+        return ret;
+}
+
+static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+        struct max8925_rtc_info *info = dev_get_drvdata(dev);
+        unsigned char buf[TIME_NUM];
+        int ret;
+
+        ret = data_calc(buf, tm, TIME_NUM);
+        if (ret < 0)
+                goto out;
+        ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
+out:
+        return ret;
+}
+
+static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct max8925_rtc_info *info = dev_get_drvdata(dev);
+        unsigned char buf[TIME_NUM];
+        int ret;
+
+        ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
+        if (ret < 0)
+                goto out;
+        ret = tm_calc(&alrm->time, buf, TIME_NUM);
+        if (ret < 0)
+                goto out;
+        ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
+        if (ret < 0)
+                goto out;
+        if ((ret & ALARM0_IRQ) == 0)
+                alrm->enabled = 1;
+        else
+                alrm->enabled = 0;
+        ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
+        if (ret < 0)
+                goto out;
+        if (ret & ALARM0_STATUS)
+                alrm->pending = 1;
+        else
+                alrm->pending = 0;
+out:
+        return ret;
+}
+
+static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct max8925_rtc_info *info = dev_get_drvdata(dev);
+        unsigned char buf[TIME_NUM];
+        int ret;
+
+        ret = data_calc(buf, &alrm->time, TIME_NUM);
+        if (ret < 0)
+                goto out;
+        ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
+        if (ret < 0)
+                goto out;
+        /* only enable alarm on year/month/day/hour/min/sec */
+        ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
+        if (ret < 0)
+                goto out;
+out:
+        return ret;
+}
+
+static const struct rtc_class_ops max8925_rtc_ops = {
+        .read_time      = max8925_rtc_read_time,
+        .set_time       = max8925_rtc_set_time,
+        .read_alarm     = max8925_rtc_read_alarm,
+        .set_alarm      = max8925_rtc_set_alarm,
+};
+
+static int __devinit max8925_rtc_probe(struct platform_device *pdev)
+{
+        struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
+        struct max8925_rtc_info *info;
+        int irq, ret;
+
+        info = kzalloc(sizeof(struct max8925_rtc_info), GFP_KERNEL);
+        if (!info)
+                return -ENOMEM;
+        info->chip = chip;
+        info->rtc = chip->rtc;
+        info->dev = &pdev->dev;
+        irq = chip->irq_base + MAX8925_IRQ_RTC_ALARM0;
+
+        ret = request_threaded_irq(irq, NULL, rtc_update_handler,
+                                   IRQF_ONESHOT, "rtc-alarm0", info);
+        if (ret < 0) {
+                dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
+                        irq, ret);
+                goto out_irq;
+        }
+
+        info->rtc_dev = rtc_device_register("max8925-rtc", &pdev->dev,
+                                        &max8925_rtc_ops, THIS_MODULE);
+        ret = PTR_ERR(info->rtc_dev);
+        if (IS_ERR(info->rtc_dev)) {
+                dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
+                goto out_rtc;
+        }
+
+        dev_set_drvdata(&pdev->dev, info);
+        platform_set_drvdata(pdev, info);
+
+        return 0;
+out_rtc:
+        free_irq(chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
+out_irq:
+        kfree(info);
+        return ret;
+}
+
+static int __devexit max8925_rtc_remove(struct platform_device *pdev)
+{
+        struct max8925_rtc_info *info = platform_get_drvdata(pdev);
+
+        if (info) {
+                free_irq(info->chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
+                rtc_device_unregister(info->rtc_dev);
+                kfree(info);
+        }
+        return 0;
+}
+
+static struct platform_driver max8925_rtc_driver = {
+        .driver         = {
+                .name   = "max8925-rtc",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = max8925_rtc_probe,
+        .remove         = __devexit_p(max8925_rtc_remove),
+};
+
+static int __init max8925_rtc_init(void)
+{
+        return platform_driver_register(&max8925_rtc_driver);
+}
+module_init(max8925_rtc_init);
+
+static void __exit max8925_rtc_exit(void)
+{
+        platform_driver_unregister(&max8925_rtc_driver);
+}
+module_exit(max8925_rtc_exit);
+
+MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");
+