rtc: s5m-rtc: add real-time clock driver for s5m8767

Add real-time clock driver for s5m8767.

Signed-off-by: Sangbeom Kim <sbkim73@samsung.com>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Todd Broch <tbroch@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Acked-by: Lee Jones <lee.jones@linaro.org>	[mfd parts]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 635 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-s5m.c b/drivers/rtc/rtc-s5m.c
new file mode 100644
index 000000000000..b7fd02bc0a14
--- /dev/null
+++ b/drivers/rtc/rtc-s5m.c
@@ -0,0 +1,635 @@
+/*
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd
+ *	http://www.samsung.com
+ *
+ *  Copyright (C) 2013 Google, Inc
+ *
+ *  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.
+ *
+ *  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.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/bcd.h>
+#include <linux/bitops.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/samsung/core.h>
+#include <linux/mfd/samsung/irq.h>
+#include <linux/mfd/samsung/rtc.h>
+
+struct s5m_rtc_info {
+	struct device *dev;
+	struct sec_pmic_dev *s5m87xx;
+	struct regmap *rtc;
+	struct rtc_device *rtc_dev;
+	int irq;
+	int device_type;
+	int rtc_24hr_mode;
+	bool wtsr_smpl;
+};
+
+static void s5m8767_data_to_tm(u8 *data, struct rtc_time *tm,
+			       int rtc_24hr_mode)
+{
+	tm->tm_sec = data[RTC_SEC] & 0x7f;
+	tm->tm_min = data[RTC_MIN] & 0x7f;
+	if (rtc_24hr_mode) {
+		tm->tm_hour = data[RTC_HOUR] & 0x1f;
+	} else {
+		tm->tm_hour = data[RTC_HOUR] & 0x0f;
+		if (data[RTC_HOUR] & HOUR_PM_MASK)
+			tm->tm_hour += 12;
+	}
+
+	tm->tm_wday = ffs(data[RTC_WEEKDAY] & 0x7f);
+	tm->tm_mday = data[RTC_DATE] & 0x1f;
+	tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
+	tm->tm_year = (data[RTC_YEAR1] & 0x7f) + 100;
+	tm->tm_yday = 0;
+	tm->tm_isdst = 0;
+}
+
+static int s5m8767_tm_to_data(struct rtc_time *tm, u8 *data)
+{
+	data[RTC_SEC] = tm->tm_sec;
+	data[RTC_MIN] = tm->tm_min;
+
+	if (tm->tm_hour >= 12)
+		data[RTC_HOUR] = tm->tm_hour | HOUR_PM_MASK;
+	else
+		data[RTC_HOUR] = tm->tm_hour & ~HOUR_PM_MASK;
+
+	data[RTC_WEEKDAY] = 1 << tm->tm_wday;
+	data[RTC_DATE] = tm->tm_mday;
+	data[RTC_MONTH] = tm->tm_mon + 1;
+	data[RTC_YEAR1] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0;
+
+	if (tm->tm_year < 100) {
+		pr_err("s5m8767 RTC cannot handle the year %d.\n",
+		       1900 + tm->tm_year);
+		return -EINVAL;
+	} else {
+		return 0;
+	}
+}
+
+static inline int s5m8767_rtc_set_time_reg(struct s5m_rtc_info *info)
+{
+	int ret;
+	unsigned int data;
+
+	ret = regmap_read(info->rtc, SEC_RTC_UDR_CON, &data);
+	if (ret < 0) {
+		dev_err(info->dev, "failed to read update reg(%d)\n", ret);
+		return ret;
+	}
+
+	data |= RTC_TIME_EN_MASK;
+	data |= RTC_UDR_MASK;
+
+	ret = regmap_write(info->rtc, SEC_RTC_UDR_CON, data);
+	if (ret < 0) {
+		dev_err(info->dev, "failed to write update reg(%d)\n", ret);
+		return ret;
+	}
+
+	do {
+		ret = regmap_read(info->rtc, SEC_RTC_UDR_CON, &data);
+	} while ((data & RTC_UDR_MASK) && !ret);
+
+	return ret;
+}
+
+static inline int s5m8767_rtc_set_alarm_reg(struct s5m_rtc_info *info)
+{
+	int ret;
+	unsigned int data;
+
+	ret = regmap_read(info->rtc, SEC_RTC_UDR_CON, &data);
+	if (ret < 0) {
+		dev_err(info->dev, "%s: fail to read update reg(%d)\n",
+			__func__, ret);
+		return ret;
+	}
+
+	data &= ~RTC_TIME_EN_MASK;
+	data |= RTC_UDR_MASK;
+
+	ret = regmap_write(info->rtc, SEC_RTC_UDR_CON, data);
+	if (ret < 0) {
+		dev_err(info->dev, "%s: fail to write update reg(%d)\n",
+			__func__, ret);
+		return ret;
+	}
+
+	do {
+		ret = regmap_read(info->rtc, SEC_RTC_UDR_CON, &data);
+	} while ((data & RTC_UDR_MASK) && !ret);
+
+	return ret;
+}
+
+static void s5m8763_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 s5m8763_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 s5m_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct s5m_rtc_info *info = dev_get_drvdata(dev);
+	u8 data[8];
+	int ret;
+
+	ret = regmap_bulk_read(info->rtc, SEC_RTC_SEC, data, 8);
+	if (ret < 0)
+		return ret;
+
+	switch (info->device_type) {
+	case S5M8763X:
+		s5m8763_data_to_tm(data, tm);
+		break;
+
+	case S5M8767X:
+		s5m8767_data_to_tm(data, tm, info->rtc_24hr_mode);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
+		1900 + tm->tm_year, 1 + tm->tm_mon, tm->tm_mday,
+		tm->tm_hour, tm->tm_min, tm->tm_sec, tm->tm_wday);
+
+	return rtc_valid_tm(tm);
+}
+
+static int s5m_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct s5m_rtc_info *info = dev_get_drvdata(dev);
+	u8 data[8];
+	int ret = 0;
+
+	switch (info->device_type) {
+	case S5M8763X:
+		s5m8763_tm_to_data(tm, data);
+		break;
+	case S5M8767X:
+		ret = s5m8767_tm_to_data(tm, data);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (ret < 0)
+		return ret;
+
+	dev_dbg(dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
+		1900 + tm->tm_year, 1 + tm->tm_mon, tm->tm_mday,
+		tm->tm_hour, tm->tm_min, tm->tm_sec, tm->tm_wday);
+
+	ret = regmap_raw_write(info->rtc, SEC_RTC_SEC, data, 8);
+	if (ret < 0)
+		return ret;
+
+	ret = s5m8767_rtc_set_time_reg(info);
+
+	return ret;
+}
+
+static int s5m_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct s5m_rtc_info *info = dev_get_drvdata(dev);
+	u8 data[8];
+	unsigned int val;
+	int ret, i;
+
+	ret = regmap_bulk_read(info->rtc, SEC_ALARM0_SEC, data, 8);
+	if (ret < 0)
+		return ret;
+
+	switch (info->device_type) {
+	case S5M8763X:
+		s5m8763_data_to_tm(data, &alrm->time);
+		ret = regmap_read(info->rtc, SEC_ALARM0_CONF, &val);
+		if (ret < 0)
+			return ret;
+
+		alrm->enabled = !!val;
+
+		ret = regmap_read(info->rtc, SEC_RTC_STATUS, &val);
+		if (ret < 0)
+			return ret;
+
+		break;
+
+	case S5M8767X:
+		s5m8767_data_to_tm(data, &alrm->time, info->rtc_24hr_mode);
+		dev_dbg(dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
+			1900 + alrm->time.tm_year, 1 + alrm->time.tm_mon,
+			alrm->time.tm_mday, alrm->time.tm_hour,
+			alrm->time.tm_min, alrm->time.tm_sec,
+			alrm->time.tm_wday);
+
+		alrm->enabled = 0;
+		for (i = 0; i < 7; i++) {
+			if (data[i] & ALARM_ENABLE_MASK) {
+				alrm->enabled = 1;
+				break;
+			}
+		}
+
+		alrm->pending = 0;
+		ret = regmap_read(info->rtc, SEC_RTC_STATUS, &val);
+		if (ret < 0)
+			return ret;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	if (val & ALARM0_STATUS)
+		alrm->pending = 1;
+	else
+		alrm->pending = 0;
+
+	return 0;
+}
+
+static int s5m_rtc_stop_alarm(struct s5m_rtc_info *info)
+{
+	u8 data[8];
+	int ret, i;
+	struct rtc_time tm;
+
+	ret = regmap_bulk_read(info->rtc, SEC_ALARM0_SEC, data, 8);
+	if (ret < 0)
+		return ret;
+
+	s5m8767_data_to_tm(data, &tm, info->rtc_24hr_mode);
+	dev_dbg(info->dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
+		1900 + tm.tm_year, 1 + tm.tm_mon, tm.tm_mday,
+		tm.tm_hour, tm.tm_min, tm.tm_sec, tm.tm_wday);
+
+	switch (info->device_type) {
+	case S5M8763X:
+		ret = regmap_write(info->rtc, SEC_ALARM0_CONF, 0);
+		break;
+
+	case S5M8767X:
+		for (i = 0; i < 7; i++)
+			data[i] &= ~ALARM_ENABLE_MASK;
+
+		ret = regmap_raw_write(info->rtc, SEC_ALARM0_SEC, data, 8);
+		if (ret < 0)
+			return ret;
+
+		ret = s5m8767_rtc_set_alarm_reg(info);
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static int s5m_rtc_start_alarm(struct s5m_rtc_info *info)
+{
+	int ret;
+	u8 data[8];
+	u8 alarm0_conf;
+	struct rtc_time tm;
+
+	ret = regmap_bulk_read(info->rtc, SEC_ALARM0_SEC, data, 8);
+	if (ret < 0)
+		return ret;
+
+	s5m8767_data_to_tm(data, &tm, info->rtc_24hr_mode);
+	dev_dbg(info->dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
+		1900 + tm.tm_year, 1 + tm.tm_mon, tm.tm_mday,
+		tm.tm_hour, tm.tm_min, tm.tm_sec, tm.tm_wday);
+
+	switch (info->device_type) {
+	case S5M8763X:
+		alarm0_conf = 0x77;
+		ret = regmap_write(info->rtc, SEC_ALARM0_CONF, alarm0_conf);
+		break;
+
+	case S5M8767X:
+		data[RTC_SEC] |= ALARM_ENABLE_MASK;
+		data[RTC_MIN] |= ALARM_ENABLE_MASK;
+		data[RTC_HOUR] |= ALARM_ENABLE_MASK;
+		data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
+		if (data[RTC_DATE] & 0x1f)
+			data[RTC_DATE] |= ALARM_ENABLE_MASK;
+		if (data[RTC_MONTH] & 0xf)
+			data[RTC_MONTH] |= ALARM_ENABLE_MASK;
+		if (data[RTC_YEAR1] & 0x7f)
+			data[RTC_YEAR1] |= ALARM_ENABLE_MASK;
+
+		ret = regmap_raw_write(info->rtc, SEC_ALARM0_SEC, data, 8);
+		if (ret < 0)
+			return ret;
+		ret = s5m8767_rtc_set_alarm_reg(info);
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static int s5m_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct s5m_rtc_info *info = dev_get_drvdata(dev);
+	u8 data[8];
+	int ret;
+
+	switch (info->device_type) {
+	case S5M8763X:
+		s5m8763_tm_to_data(&alrm->time, data);
+		break;
+
+	case S5M8767X:
+		s5m8767_tm_to_data(&alrm->time, data);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
+		1900 + alrm->time.tm_year, 1 + alrm->time.tm_mon,
+		alrm->time.tm_mday, alrm->time.tm_hour, alrm->time.tm_min,
+		alrm->time.tm_sec, alrm->time.tm_wday);
+
+	ret = s5m_rtc_stop_alarm(info);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_raw_write(info->rtc, SEC_ALARM0_SEC, data, 8);
+	if (ret < 0)
+		return ret;
+
+	ret = s5m8767_rtc_set_alarm_reg(info);
+	if (ret < 0)
+		return ret;
+
+	if (alrm->enabled)
+		ret = s5m_rtc_start_alarm(info);
+
+	return ret;
+}
+
+static int s5m_rtc_alarm_irq_enable(struct device *dev,
+				    unsigned int enabled)
+{
+	struct s5m_rtc_info *info = dev_get_drvdata(dev);
+
+	if (enabled)
+		return s5m_rtc_start_alarm(info);
+	else
+		return s5m_rtc_stop_alarm(info);
+}
+
+static irqreturn_t s5m_rtc_alarm_irq(int irq, void *data)
+{
+	struct s5m_rtc_info *info = data;
+
+	rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
+
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops s5m_rtc_ops = {
+	.read_time = s5m_rtc_read_time,
+	.set_time = s5m_rtc_set_time,
+	.read_alarm = s5m_rtc_read_alarm,
+	.set_alarm = s5m_rtc_set_alarm,
+	.alarm_irq_enable = s5m_rtc_alarm_irq_enable,
+};
+
+static void s5m_rtc_enable_wtsr(struct s5m_rtc_info *info, bool enable)
+{
+	int ret;
+	ret = regmap_update_bits(info->rtc, SEC_WTSR_SMPL_CNTL,
+				 WTSR_ENABLE_MASK,
+				 enable ? WTSR_ENABLE_MASK : 0);
+	if (ret < 0)
+		dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n",
+			__func__, ret);
+}
+
+static void s5m_rtc_enable_smpl(struct s5m_rtc_info *info, bool enable)
+{
+	int ret;
+	ret = regmap_update_bits(info->rtc, SEC_WTSR_SMPL_CNTL,
+				 SMPL_ENABLE_MASK,
+				 enable ? SMPL_ENABLE_MASK : 0);
+	if (ret < 0)
+		dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n",
+			__func__, ret);
+}
+
+static int s5m8767_rtc_init_reg(struct s5m_rtc_info *info)
+{
+	u8 data[2];
+	unsigned int tp_read;
+	int ret;
+	struct rtc_time tm;
+
+	ret = regmap_read(info->rtc, SEC_RTC_UDR_CON, &tp_read);
+	if (ret < 0) {
+		dev_err(info->dev, "%s: fail to read control reg(%d)\n",
+			__func__, ret);
+		return ret;
+	}
+
+	/* Set RTC control register : Binary mode, 24hour mode */
+	data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
+	data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
+
+	info->rtc_24hr_mode = 1;
+	ret = regmap_raw_write(info->rtc, SEC_ALARM0_CONF, data, 2);
+	if (ret < 0) {
+		dev_err(info->dev, "%s: fail to write controlm reg(%d)\n",
+			__func__, ret);
+		return ret;
+	}
+
+	/* In first boot time, Set rtc time to 1/1/2012 00:00:00(SUN) */
+	if ((tp_read & RTC_TCON_MASK) == 0) {
+		dev_dbg(info->dev, "rtc init\n");
+		tm.tm_sec = 0;
+		tm.tm_min = 0;
+		tm.tm_hour = 0;
+		tm.tm_wday = 0;
+		tm.tm_mday = 1;
+		tm.tm_mon = 0;
+		tm.tm_year = 112;
+		tm.tm_yday = 0;
+		tm.tm_isdst = 0;
+		ret = s5m_rtc_set_time(info->dev, &tm);
+	}
+
+	ret = regmap_update_bits(info->rtc, SEC_RTC_UDR_CON,
+				 RTC_TCON_MASK, tp_read | RTC_TCON_MASK);
+	if (ret < 0)
+		dev_err(info->dev, "%s: fail to update TCON reg(%d)\n",
+			__func__, ret);
+
+	return ret;
+}
+
+static int s5m_rtc_probe(struct platform_device *pdev)
+{
+	struct sec_pmic_dev *s5m87xx = dev_get_drvdata(pdev->dev.parent);
+	struct sec_platform_data *pdata = s5m87xx->pdata;
+	struct s5m_rtc_info *info;
+	int ret;
+
+	if (!pdata) {
+		dev_err(pdev->dev.parent, "Platform data not supplied\n");
+		return -ENODEV;
+	}
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->dev = &pdev->dev;
+	info->s5m87xx = s5m87xx;
+	info->rtc = s5m87xx->rtc;
+	info->device_type = s5m87xx->device_type;
+	info->wtsr_smpl = s5m87xx->wtsr_smpl;
+
+	switch (pdata->device_type) {
+	case S5M8763X:
+		info->irq = s5m87xx->irq_base + S5M8763_IRQ_ALARM0;
+		break;
+
+	case S5M8767X:
+		info->irq = s5m87xx->irq_base + S5M8767_IRQ_RTCA1;
+		break;
+
+	default:
+		ret = -EINVAL;
+		dev_err(&pdev->dev, "Unsupported device type: %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, info);
+
+	ret = s5m8767_rtc_init_reg(info);
+
+	if (info->wtsr_smpl) {
+		s5m_rtc_enable_wtsr(info, true);
+		s5m_rtc_enable_smpl(info, true);
+	}
+
+	device_init_wakeup(&pdev->dev, 1);
+
+	info->rtc_dev = devm_rtc_device_register(&pdev->dev, "s5m-rtc",
+						 &s5m_rtc_ops, THIS_MODULE);
+
+	if (IS_ERR(info->rtc_dev))
+		return PTR_ERR(info->rtc_dev);
+
+	ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
+					s5m_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 ret;
+}
+
+static void s5m_rtc_shutdown(struct platform_device *pdev)
+{
+	struct s5m_rtc_info *info = platform_get_drvdata(pdev);
+	int i;
+	unsigned int val = 0;
+	if (info->wtsr_smpl) {
+		for (i = 0; i < 3; i++) {
+			s5m_rtc_enable_wtsr(info, false);
+			regmap_read(info->rtc, SEC_WTSR_SMPL_CNTL, &val);
+			pr_debug("%s: WTSR_SMPL reg(0x%02x)\n", __func__, val);
+			if (val & WTSR_ENABLE_MASK)
+				pr_emerg("%s: fail to disable WTSR\n",
+					 __func__);
+			else {
+				pr_info("%s: success to disable WTSR\n",
+					__func__);
+				break;
+			}
+		}
+	}
+	/* Disable SMPL when power off */
+	s5m_rtc_enable_smpl(info, false);
+}
+
+static const struct platform_device_id s5m_rtc_id[] = {
+	{ "s5m-rtc", 0 },
+};
+
+static struct platform_driver s5m_rtc_driver = {
+	.driver		= {
+		.name	= "s5m-rtc",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= s5m_rtc_probe,
+	.shutdown	= s5m_rtc_shutdown,
+	.id_table	= s5m_rtc_id,
+};
+
+module_platform_driver(s5m_rtc_driver);
+
+/* Module information */
+MODULE_AUTHOR("Sangbeom Kim <sbkim73@samsung.com>");
+MODULE_DESCRIPTION("Samsung S5M RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:s5m-rtc");