1 files changed, 334 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-da9052.c b/drivers/rtc/rtc-da9052.c
new file mode 100644
index 000000000..03044e1bc
--- /dev/null
+++ b/drivers/rtc/rtc-da9052.c
@@ -0,0 +1,334 @@
+/*
+ * Real time clock driver for DA9052
+ *
+ * Copyright(c) 2012 Dialog Semiconductor Ltd.
+ *
+ * Author: Dajun Dajun Chen <dajun.chen@diasemi.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/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+
+#include <linux/mfd/da9052/da9052.h>
+#include <linux/mfd/da9052/reg.h>
+
+#define rtc_err(rtc, fmt, ...) \
+		dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)
+
+#define DA9052_GET_TIME_RETRIES 5
+
+struct da9052_rtc {
+	struct rtc_device *rtc;
+	struct da9052 *da9052;
+};
+
+static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable)
+{
+	int ret;
+	if (enable) {
+		ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
+				DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON,
+				DA9052_ALARM_Y_ALARM_ON);
+		if (ret != 0)
+			rtc_err(rtc, "Failed to enable ALM: %d\n", ret);
+	} else {
+		ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
+			DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0);
+		if (ret != 0)
+			rtc_err(rtc, "Write error: %d\n", ret);
+	}
+	return ret;
+}
+
+static irqreturn_t da9052_rtc_irq(int irq, void *data)
+{
+	struct da9052_rtc *rtc = data;
+
+	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
+
+	return IRQ_HANDLED;
+}
+
+static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
+{
+	int ret;
+	uint8_t v[2][5];
+	int idx = 1;
+	int timeout = DA9052_GET_TIME_RETRIES;
+
+	ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, &v[0][0]);
+	if (ret) {
+		rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
+		return ret;
+	}
+
+	do {
+		ret = da9052_group_read(rtc->da9052,
+					DA9052_ALARM_MI_REG, 5, &v[idx][0]);
+		if (ret) {
+			rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
+			return ret;
+		}
+
+		if (memcmp(&v[0][0], &v[1][0], 5) == 0) {
+			rtc_tm->tm_year = (v[0][4] & DA9052_RTC_YEAR) + 100;
+			rtc_tm->tm_mon  = (v[0][3] & DA9052_RTC_MONTH) - 1;
+			rtc_tm->tm_mday = v[0][2] & DA9052_RTC_DAY;
+			rtc_tm->tm_hour = v[0][1] & DA9052_RTC_HOUR;
+			rtc_tm->tm_min  = v[0][0] & DA9052_RTC_MIN;
+			rtc_tm->tm_sec = 0;
+
+			ret = rtc_valid_tm(rtc_tm);
+			return ret;
+		}
+
+		idx = (1-idx);
+		msleep(20);
+
+	} while (timeout--);
+
+	rtc_err(rtc, "Timed out reading alarm time\n");
+
+	return -EIO;
+}
+
+static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
+{
+	struct da9052 *da9052 = rtc->da9052;
+	unsigned long alm_time;
+	int ret;
+	uint8_t v[3];
+
+	ret = rtc_tm_to_time(rtc_tm, &alm_time);
+	if (ret != 0)
+		return ret;
+
+	if (rtc_tm->tm_sec > 0) {
+		alm_time += 60 - rtc_tm->tm_sec;
+		rtc_time_to_tm(alm_time, rtc_tm);
+	}
+	BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
+
+	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(rtc, "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(rtc, "Failed to write ALRM YEAR: %d\n", ret);
+
+	return ret;
+}
+
+static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
+{
+	int ret;
+
+	ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
+	if (ret < 0) {
+		rtc_err(rtc, "Failed to read ALM: %d\n", ret);
+		return ret;
+	}
+
+	return !!(ret&DA9052_ALARM_Y_ALARM_ON);
+}
+
+static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
+{
+	struct da9052_rtc *rtc = dev_get_drvdata(dev);
+	int ret;
+	uint8_t v[2][6];
+	int idx = 1;
+	int timeout = DA9052_GET_TIME_RETRIES;
+
+	ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]);
+	if (ret) {
+		rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
+		return ret;
+	}
+
+	do {
+		ret = da9052_group_read(rtc->da9052,
+					DA9052_COUNT_S_REG, 6, &v[idx][0]);
+		if (ret) {
+			rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
+			return ret;
+		}
+
+		if (memcmp(&v[0][0], &v[1][0], 6) == 0) {
+			rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100;
+			rtc_tm->tm_mon  = (v[0][4] & DA9052_RTC_MONTH) - 1;
+			rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY;
+			rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR;
+			rtc_tm->tm_min  = v[0][1] & DA9052_RTC_MIN;
+			rtc_tm->tm_sec  = v[0][0] & DA9052_RTC_SEC;
+
+			return 0;
+		}
+
+		idx = (1-idx);
+		msleep(20);
+
+	} while (timeout--);
+
+	rtc_err(rtc, "Timed out reading time\n");
+
+	return -EIO;
+}
+
+static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct da9052_rtc *rtc;
+	uint8_t v[6];
+	int ret;
+
+	/* DA9052 only has 6 bits for year - to represent 2000-2063 */
+	if ((tm->tm_year < 100) || (tm->tm_year > 163))
+		return -EINVAL;
+
+	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;
+
+	ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
+	if (ret < 0)
+		rtc_err(rtc, "failed to set RTC time: %d\n", ret);
+	return ret;
+}
+
+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, tm);
+	if (ret < 0) {
+		rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
+		return ret;
+	}
+
+	alrm->enabled = da9052_rtc_get_alarm_status(rtc);
+	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);
+
+	/* DA9052 only has 6 bits for year - to represent 2000-2063 */
+	if ((tm->tm_year < 100) || (tm->tm_year > 163))
+		return -EINVAL;
+
+	ret = da9052_rtc_enable_alarm(rtc, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = da9052_set_alarm(rtc, tm);
+	if (ret < 0)
+		return ret;
+
+	ret = da9052_rtc_enable_alarm(rtc, 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, 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 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);
+
+	ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
+	if (ret < 0) {
+		rtc_err(rtc,
+			"Failed to setup RTC battery charging: %d\n", ret);
+		return ret;
+	}
+
+	ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
+				DA9052_ALARM_Y_TICK_ON, 0);
+	if (ret != 0)
+		rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
+
+	device_init_wakeup(&pdev->dev, true);
+	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+				       &da9052_rtc_ops, THIS_MODULE);
+
+	if (IS_ERR(rtc->rtc))
+		return PTR_ERR(rtc->rtc);
+
+	ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
+				da9052_rtc_irq, rtc);
+	if (ret != 0) {
+		rtc_err(rtc, "irq registration failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static struct platform_driver da9052_rtc_driver = {
+	.probe	= da9052_rtc_probe,
+	.driver = {
+		.name	= "da9052-rtc",
+	},
+};
+
+module_platform_driver(da9052_rtc_driver);
+
+MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
+MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9052-rtc");