rtc: Add MAX8998 rtc driver
This adds support for the RTC provided by the Maxim 8998 chip. This
driver was tested on a GONI board by using the rtc-test application from
the Documentation/rtc.txt.
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/rtc/rtc-max8998.c b/drivers/rtc/rtc-max8998.c
new file mode 100644
index 0000000..f22dee3
--- /dev/null
+++ b/drivers/rtc/rtc-max8998.c
@@ -0,0 +1,300 @@
+/*
+ * RTC driver for Maxim MAX8998
+ *
+ * Copyright (C) 2010 Samsung Electronics Co.Ltd
+ * Author: Minkyu Kang <mk7.kang@samsung.com>
+ * Author: Joonyoung Shim <jy0922.shim@samsung.com>
+ *
+ * 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/i2c.h>
+#include <linux/slab.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/max8998.h>
+#include <linux/mfd/max8998-private.h>
+
+#define MAX8998_RTC_SEC 0x00
+#define MAX8998_RTC_MIN 0x01
+#define MAX8998_RTC_HOUR 0x02
+#define MAX8998_RTC_WEEKDAY 0x03
+#define MAX8998_RTC_DATE 0x04
+#define MAX8998_RTC_MONTH 0x05
+#define MAX8998_RTC_YEAR1 0x06
+#define MAX8998_RTC_YEAR2 0x07
+#define MAX8998_ALARM0_SEC 0x08
+#define MAX8998_ALARM0_MIN 0x09
+#define MAX8998_ALARM0_HOUR 0x0a
+#define MAX8998_ALARM0_WEEKDAY 0x0b
+#define MAX8998_ALARM0_DATE 0x0c
+#define MAX8998_ALARM0_MONTH 0x0d
+#define MAX8998_ALARM0_YEAR1 0x0e
+#define MAX8998_ALARM0_YEAR2 0x0f
+#define MAX8998_ALARM1_SEC 0x10
+#define MAX8998_ALARM1_MIN 0x11
+#define MAX8998_ALARM1_HOUR 0x12
+#define MAX8998_ALARM1_WEEKDAY 0x13
+#define MAX8998_ALARM1_DATE 0x14
+#define MAX8998_ALARM1_MONTH 0x15
+#define MAX8998_ALARM1_YEAR1 0x16
+#define MAX8998_ALARM1_YEAR2 0x17
+#define MAX8998_ALARM0_CONF 0x18
+#define MAX8998_ALARM1_CONF 0x19
+#define MAX8998_RTC_STATUS 0x1a
+#define MAX8998_WTSR_SMPL_CNTL 0x1b
+#define MAX8998_TEST 0x1f
+
+#define HOUR_12 (1 << 7)
+#define HOUR_PM (1 << 5)
+#define ALARM0_STATUS (1 << 1)
+#define ALARM1_STATUS (1 << 2)
+
+enum {
+ RTC_SEC = 0,
+ RTC_MIN,
+ RTC_HOUR,
+ RTC_WEEKDAY,
+ RTC_DATE,
+ RTC_MONTH,
+ RTC_YEAR1,
+ RTC_YEAR2,
+};
+
+struct max8998_rtc_info {
+ struct device *dev;
+ struct max8998_dev *max8998;
+ struct i2c_client *rtc;
+ struct rtc_device *rtc_dev;
+ int irq;
+};
+
+static void max8998_data_to_tm(u8 *data, struct rtc_time *tm)
+{
+ tm->tm_sec = bcd2bin(data[RTC_SEC]);
+ tm->tm_min = bcd2bin(data[RTC_MIN]);
+ if (data[RTC_HOUR] & HOUR_12) {
+ tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f);
+ if (data[RTC_HOUR] & HOUR_PM)
+ tm->tm_hour += 12;
+ } else
+ tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);
+
+ tm->tm_wday = data[RTC_WEEKDAY] & 0x07;
+ tm->tm_mday = bcd2bin(data[RTC_DATE]);
+ tm->tm_mon = bcd2bin(data[RTC_MONTH]);
+ tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100;
+ tm->tm_year -= 1900;
+}
+
+static void max8998_tm_to_data(struct rtc_time *tm, u8 *data)
+{
+ data[RTC_SEC] = bin2bcd(tm->tm_sec);
+ data[RTC_MIN] = bin2bcd(tm->tm_min);
+ data[RTC_HOUR] = bin2bcd(tm->tm_hour);
+ data[RTC_WEEKDAY] = tm->tm_wday;
+ data[RTC_DATE] = bin2bcd(tm->tm_mday);
+ data[RTC_MONTH] = bin2bcd(tm->tm_mon);
+ data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100);
+ data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100);
+}
+
+static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max8998_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[8];
+ int ret;
+
+ ret = max8998_bulk_read(info->rtc, MAX8998_RTC_SEC, 8, data);
+ if (ret < 0)
+ return ret;
+
+ max8998_data_to_tm(data, tm);
+
+ return rtc_valid_tm(tm);
+}
+
+static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max8998_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[8];
+
+ max8998_tm_to_data(tm, data);
+
+ return max8998_bulk_write(info->rtc, MAX8998_RTC_SEC, 8, data);
+}
+
+static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max8998_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[8];
+ u8 val;
+ int ret;
+
+ ret = max8998_bulk_read(info->rtc, MAX8998_ALARM0_SEC, 8, data);
+ if (ret < 0)
+ return ret;
+
+ max8998_data_to_tm(data, &alrm->time);
+
+ ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val);
+ if (ret < 0)
+ return ret;
+
+ alrm->enabled = !!val;
+
+ ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &val);
+ if (ret < 0)
+ return ret;
+
+ if (val & ALARM0_STATUS)
+ alrm->pending = 1;
+ else
+ alrm->pending = 0;
+
+ return 0;
+}
+
+static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info)
+{
+ return max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0);
+}
+
+static int max8998_rtc_start_alarm(struct max8998_rtc_info *info)
+{
+ return max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0x77);
+}
+
+static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max8998_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[8];
+ int ret;
+
+ max8998_tm_to_data(&alrm->time, data);
+
+ ret = max8998_rtc_stop_alarm(info);
+ if (ret < 0)
+ return ret;
+
+ ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data);
+ if (ret < 0)
+ return ret;
+
+ if (alrm->enabled)
+ return max8998_rtc_start_alarm(info);
+
+ return 0;
+}
+
+static int max8998_rtc_alarm_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct max8998_rtc_info *info = dev_get_drvdata(dev);
+
+ if (enabled)
+ return max8998_rtc_start_alarm(info);
+ else
+ return max8998_rtc_stop_alarm(info);
+}
+
+static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data)
+{
+ struct max8998_rtc_info *info = data;
+
+ rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
+
+ return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops max8998_rtc_ops = {
+ .read_time = max8998_rtc_read_time,
+ .set_time = max8998_rtc_set_time,
+ .read_alarm = max8998_rtc_read_alarm,
+ .set_alarm = max8998_rtc_set_alarm,
+ .alarm_irq_enable = max8998_rtc_alarm_irq_enable,
+};
+
+static int __devinit max8998_rtc_probe(struct platform_device *pdev)
+{
+ struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent);
+ struct max8998_rtc_info *info;
+ int ret;
+
+ info = kzalloc(sizeof(struct max8998_rtc_info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ info->dev = &pdev->dev;
+ info->max8998 = max8998;
+ info->rtc = max8998->rtc;
+ info->irq = max8998->irq_base + MAX8998_IRQ_ALARM0;
+
+ info->rtc_dev = rtc_device_register("max8998-rtc", &pdev->dev,
+ &max8998_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;
+ }
+
+ platform_set_drvdata(pdev, info);
+
+ ret = request_threaded_irq(info->irq, NULL, max8998_rtc_alarm_irq, 0,
+ "rtc-alarm0", info);
+ if (ret < 0)
+ dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
+ info->irq, ret);
+
+ return 0;
+
+out_rtc:
+ kfree(info);
+ return ret;
+}
+
+static int __devexit max8998_rtc_remove(struct platform_device *pdev)
+{
+ struct max8998_rtc_info *info = platform_get_drvdata(pdev);
+
+ if (info) {
+ free_irq(info->irq, info);
+ rtc_device_unregister(info->rtc_dev);
+ kfree(info);
+ }
+
+ return 0;
+}
+
+static struct platform_driver max8998_rtc_driver = {
+ .driver = {
+ .name = "max8998-rtc",
+ .owner = THIS_MODULE,
+ },
+ .probe = max8998_rtc_probe,
+ .remove = __devexit_p(max8998_rtc_remove),
+};
+
+static int __init max8998_rtc_init(void)
+{
+ return platform_driver_register(&max8998_rtc_driver);
+}
+module_init(max8998_rtc_init);
+
+static void __exit max8998_rtc_exit(void)
+{
+ platform_driver_unregister(&max8998_rtc_driver);
+}
+module_exit(max8998_rtc_exit);
+
+MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
+MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
+MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");
+MODULE_LICENSE("GPL");