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path: root/drivers/rtc/rtc-max8907.c
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Diffstat (limited to 'drivers/rtc/rtc-max8907.c')
-rw-r--r--drivers/rtc/rtc-max8907.c221
1 files changed, 221 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-max8907.c b/drivers/rtc/rtc-max8907.c
new file mode 100644
index 000000000..db3495d10
--- /dev/null
+++ b/drivers/rtc/rtc-max8907.c
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * RTC driver for Maxim MAX8907
+ *
+ * Copyright (c) 2011-2012, NVIDIA Corporation.
+ *
+ * Based on drivers/rtc/rtc-max8925.c,
+ * Copyright (C) 2009-2010 Marvell International Ltd.
+ */
+
+#include <linux/bcd.h>
+#include <linux/i2c.h>
+#include <linux/mfd/max8907.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+enum {
+ RTC_SEC = 0,
+ RTC_MIN,
+ RTC_HOUR,
+ RTC_WEEKDAY,
+ RTC_DATE,
+ RTC_MONTH,
+ RTC_YEAR1,
+ RTC_YEAR2,
+};
+
+#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 max8907_rtc {
+ struct max8907 *max8907;
+ struct regmap *regmap;
+ struct rtc_device *rtc_dev;
+ int irq;
+};
+
+static irqreturn_t max8907_irq_handler(int irq, void *data)
+{
+ struct max8907_rtc *rtc = data;
+
+ regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0);
+
+ rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
+
+ return IRQ_HANDLED;
+}
+
+static void regs_to_tm(u8 *regs, struct rtc_time *tm)
+{
+ tm->tm_year = bcd2bin(regs[RTC_YEAR2]) * 100 +
+ bcd2bin(regs[RTC_YEAR1]) - 1900;
+ tm->tm_mon = bcd2bin(regs[RTC_MONTH] & 0x1f) - 1;
+ tm->tm_mday = bcd2bin(regs[RTC_DATE] & 0x3f);
+ tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07);
+ if (regs[RTC_HOUR] & HOUR_12) {
+ tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x01f);
+ if (tm->tm_hour == 12)
+ tm->tm_hour = 0;
+ if (regs[RTC_HOUR] & HOUR_AM_PM)
+ tm->tm_hour += 12;
+ } else {
+ tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x03f);
+ }
+ tm->tm_min = bcd2bin(regs[RTC_MIN] & 0x7f);
+ tm->tm_sec = bcd2bin(regs[RTC_SEC] & 0x7f);
+}
+
+static void tm_to_regs(struct rtc_time *tm, u8 *regs)
+{
+ u8 high, low;
+
+ high = (tm->tm_year + 1900) / 100;
+ low = tm->tm_year % 100;
+ regs[RTC_YEAR2] = bin2bcd(high);
+ regs[RTC_YEAR1] = bin2bcd(low);
+ regs[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
+ regs[RTC_DATE] = bin2bcd(tm->tm_mday);
+ regs[RTC_WEEKDAY] = tm->tm_wday;
+ regs[RTC_HOUR] = bin2bcd(tm->tm_hour);
+ regs[RTC_MIN] = bin2bcd(tm->tm_min);
+ regs[RTC_SEC] = bin2bcd(tm->tm_sec);
+}
+
+static int max8907_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max8907_rtc *rtc = dev_get_drvdata(dev);
+ u8 regs[TIME_NUM];
+ int ret;
+
+ ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_RTC_SEC, regs,
+ TIME_NUM);
+ if (ret < 0)
+ return ret;
+
+ regs_to_tm(regs, tm);
+
+ return 0;
+}
+
+static int max8907_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max8907_rtc *rtc = dev_get_drvdata(dev);
+ u8 regs[TIME_NUM];
+
+ tm_to_regs(tm, regs);
+
+ return regmap_bulk_write(rtc->regmap, MAX8907_REG_RTC_SEC, regs,
+ TIME_NUM);
+}
+
+static int max8907_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max8907_rtc *rtc = dev_get_drvdata(dev);
+ u8 regs[TIME_NUM];
+ unsigned int val;
+ int ret;
+
+ ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs,
+ TIME_NUM);
+ if (ret < 0)
+ return ret;
+
+ regs_to_tm(regs, &alrm->time);
+
+ ret = regmap_read(rtc->regmap, MAX8907_REG_ALARM0_CNTL, &val);
+ if (ret < 0)
+ return ret;
+
+ alrm->enabled = !!(val & 0x7f);
+
+ return 0;
+}
+
+static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max8907_rtc *rtc = dev_get_drvdata(dev);
+ u8 regs[TIME_NUM];
+ int ret;
+
+ tm_to_regs(&alrm->time, regs);
+
+ /* Disable alarm while we update the target time */
+ ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_bulk_write(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs,
+ TIME_NUM);
+ if (ret < 0)
+ return ret;
+
+ if (alrm->enabled)
+ ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x77);
+
+ return ret;
+}
+
+static const struct rtc_class_ops max8907_rtc_ops = {
+ .read_time = max8907_rtc_read_time,
+ .set_time = max8907_rtc_set_time,
+ .read_alarm = max8907_rtc_read_alarm,
+ .set_alarm = max8907_rtc_set_alarm,
+};
+
+static int max8907_rtc_probe(struct platform_device *pdev)
+{
+ struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent);
+ struct max8907_rtc *rtc;
+ int ret;
+
+ rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+ if (!rtc)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, rtc);
+
+ rtc->max8907 = max8907;
+ rtc->regmap = max8907->regmap_rtc;
+
+ rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8907-rtc",
+ &max8907_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc->rtc_dev)) {
+ ret = PTR_ERR(rtc->rtc_dev);
+ dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
+ return ret;
+ }
+
+ rtc->irq = regmap_irq_get_virq(max8907->irqc_rtc,
+ MAX8907_IRQ_RTC_ALARM0);
+ if (rtc->irq < 0)
+ return rtc->irq;
+
+ ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
+ max8907_irq_handler,
+ IRQF_ONESHOT, "max8907-alarm0", rtc);
+ if (ret < 0)
+ dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n",
+ rtc->irq, ret);
+
+ return ret;
+}
+
+static struct platform_driver max8907_rtc_driver = {
+ .driver = {
+ .name = "max8907-rtc",
+ },
+ .probe = max8907_rtc_probe,
+};
+module_platform_driver(max8907_rtc_driver);
+
+MODULE_DESCRIPTION("Maxim MAX8907 RTC driver");
+MODULE_LICENSE("GPL v2");