rtc: ricoh583: add ricoh583 PMU RTC driver

Add Ricoh583 PMU RTC driver along with make files.

bug 902137

Change-Id: If9a62ca897e4d41735c7638fff17c7b7570bc3c6
Signed-off-by: venu byravarasu <vbyravarasu@nvidia.com>
Reviewed-on: http://git-master/r/70017
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>

Rebase-Id: Rd6ca9940d644994ee111f2a15a3bc0b57adbfd27

3 files changed, 405 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index c8ded466b56b..b1524a16a5cd 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1241,6 +1241,16 @@ config RTC_DRV_LOONGSON1
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-ls1x.
 
+config RTC_DRV_RC5T583
+	tristate "RICOH RC5T583 PMU RTC driver"
+	depends on MFD_RICOH583
+	default n
+	help
+	  If you say yes here you get support for the RICOH RC5T583 RTC module.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-rc5t583.
+
 config RTC_DRV_MXC
 	tristate "Freescale MXC Real Time Clock"
 	depends on ARCH_MXC
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 0ce8194bf9f1..7cf9d56ba5cd 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -120,6 +120,7 @@ obj-$(CONFIG_RTC_DRV_TEGRA)	+= rtc-tegra.o
 obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o
 obj-$(CONFIG_RTC_DRV_TILE)	+= rtc-tile.o
 obj-$(CONFIG_RTC_DRV_TPS6591x)	+= rtc-tps6591x.o
+obj-$(CONFIG_RTC_DRV_RC5T583)	+= rtc-ricoh583.o
 obj-$(CONFIG_RTC_DRV_TWL4030)	+= rtc-twl.o
 obj-$(CONFIG_RTC_DRV_TPS6586X)	+= rtc-tps6586x.o
 obj-$(CONFIG_RTC_DRV_TPS65910)	+= rtc-tps65910.o
diff --git a/drivers/rtc/rtc-ricoh583.c b/drivers/rtc/rtc-ricoh583.c
new file mode 100644
index 000000000000..6b4767aa6884
--- /dev/null
+++ b/drivers/rtc/rtc-ricoh583.c
@@ -0,0 +1,394 @@
+/*
+ * drivers/rtc/rtc_ricoh583.c
+ *
+ * rtc driver for ricoh rc5t583 pmu
+ *
+ * copyright (c) 2011, nvidia corporation.
+ *
+ * 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.
+ *
+ * you should have received a copy of the gnu general public license along
+ * with this program; if not, write to the free software foundation, inc.,
+ * 51 franklin street, fifth floor, boston, ma  02110-1301, usa.
+ */
+
+/* #define debug		1 */
+/* #define verbose_debug	1 */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mfd/ricoh583.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#define rtc_ctrl1		0xED
+#define rtc_ctrl2		0xEE
+#define rtc_seconds_reg		0xE0
+#define rtc_alarm_y		0xF0
+#define rtc_adjust		0xE7
+
+/*
+linux rtc driver refers 1900 as base year in many calculations.
+(e.g. refer drivers/rtc/rtc-lib.c)
+*/
+#define os_ref_year 1900
+
+/*
+	pmu rtc have only 2 nibbles to store year information, so using an offset
+	of 100 to set the base year as 2000 for our driver.
+*/
+#define rtc_year_offset 100
+
+struct ricoh583_rtc {
+	unsigned long		epoch_start;
+	int			irq;
+	struct rtc_device	*rtc;
+	bool			irq_en;
+};
+
+static int ricoh583_read_regs(struct device *dev, int reg, int len,
+	uint8_t *val)
+{
+	int ret;
+
+	ret = ricoh583_bulk_reads(dev->parent, reg, len, val);
+	if (ret < 0) {
+		dev_err(dev->parent, "\n %s failed reading from 0x%02x\n",
+			__func__, reg);
+		WARN_ON(1);
+	}
+	return ret;
+}
+
+static int ricoh583_write_regs(struct device *dev, int reg, int len,
+	uint8_t *val)
+{
+	int ret;
+	ret = ricoh583_bulk_writes(dev->parent, reg, len, val);
+	if (ret < 0) {
+		dev_err(dev->parent, "\n %s failed writing\n", __func__);
+		WARN_ON(1);
+	}
+
+	return ret;
+}
+
+static int ricoh583_rtc_valid_tm(struct rtc_time *tm)
+{
+	if (tm->tm_year >= (rtc_year_offset + 99)
+		|| tm->tm_mon >= 12
+		|| tm->tm_mday < 1
+		|| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + os_ref_year)
+		|| tm->tm_hour >= 24
+		|| tm->tm_min >= 60
+		|| tm->tm_sec >= 60)
+		return -EINVAL;
+	return 0;
+}
+
+static u8 dec2bcd(u8 dec)
+{
+	return ((dec/10)<<4)+(dec%10);
+}
+
+static u8 bcd2dec(u8 bcd)
+{
+	return (bcd >> 4)*10+(bcd & 0xf);
+}
+
+static void convert_bcd_to_decimal(u8 *buf, u8 len)
+{
+	int i = 0;
+	for (i = 0; i < len; i++)
+		buf[i] = bcd2dec(buf[i]);
+}
+
+static void convert_decimal_to_bcd(u8 *buf, u8 len)
+{
+	int i = 0;
+	for (i = 0; i < len; i++)
+		buf[i] = dec2bcd(buf[i]);
+}
+
+static void print_time(struct device *dev, struct rtc_time *tm)
+{
+	dev_info(dev, "rtc-time : %d/%d/%d %d:%d\n",
+		(tm->tm_mon + 1), tm->tm_mday, (tm->tm_year + os_ref_year),
+		tm->tm_hour, tm->tm_min);
+}
+
+static int ricoh583_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	u8 buff[7];
+	int err;
+	err = ricoh583_read_regs(dev, rtc_seconds_reg, sizeof(buff), buff);
+	if (err < 0) {
+		dev_err(dev, "\n %s :: failed to read time\n", __FILE__);
+		return err;
+	}
+	convert_bcd_to_decimal(buff, sizeof(buff));
+	tm->tm_sec  = buff[0];
+	tm->tm_min  = buff[1];
+	tm->tm_hour = buff[2];
+	tm->tm_wday = buff[3];
+	tm->tm_mday = buff[4];
+	tm->tm_mon  = buff[5];
+	tm->tm_year = buff[6];
+	print_time(dev, tm);
+	return ricoh583_rtc_valid_tm(tm);
+}
+
+static int ricoh583_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	u8 buff[7];
+	int err;
+
+	buff[0] = tm->tm_sec;
+	buff[1] = tm->tm_min;
+	buff[2] = tm->tm_hour;
+	buff[3] = tm->tm_wday;
+	buff[4] = tm->tm_mday;
+	buff[5] = tm->tm_mon;
+	buff[6] = tm->tm_year;
+
+	print_time(dev, tm);
+
+	convert_decimal_to_bcd(buff, sizeof(buff));
+	err = ricoh583_write_regs(dev, rtc_seconds_reg, sizeof(buff), buff);
+	if (err < 0) {
+		dev_err(dev->parent, "\n failed to program new time\n");
+		return err;
+	}
+
+	return 0;
+}
+static int ricoh583_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm);
+
+static int ricoh583_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct ricoh583_rtc *rtc = dev_get_drvdata(dev);
+	unsigned long seconds;
+	u8 buff[5];
+	int err;
+	struct rtc_time tm;
+
+	if (rtc->irq == -1)
+		return -EIO;
+
+	dev_info(dev->parent, "\n setting alarm to requested time::\n");
+	print_time(dev->parent, &alrm->time);
+	rtc_tm_to_time(&alrm->time, &seconds);
+	ricoh583_rtc_read_time(dev, &tm);
+	rtc_tm_to_time(&tm, &rtc->epoch_start);
+
+	if (WARN_ON(alrm->enabled && (seconds < rtc->epoch_start))) {
+		dev_err(dev->parent, "\n can't set alarm to requested time\n");
+		return -EINVAL;
+	}
+
+	if (alrm->enabled && !rtc->irq_en) {
+		rtc->irq_en = true;
+	} else if (!alrm->enabled && rtc->irq_en) {
+		rtc->irq_en = false;
+	}
+
+	buff[0] = alrm->time.tm_min;
+	buff[1] = alrm->time.tm_hour;
+	buff[2] = alrm->time.tm_mday;
+	buff[3] = alrm->time.tm_mon;
+	buff[4] = alrm->time.tm_year;
+	convert_decimal_to_bcd(buff, sizeof(buff));
+	err = ricoh583_write_regs(dev, rtc_alarm_y, sizeof(buff), buff);
+	if (err){
+		dev_err(dev->parent, "\n unable to set alarm\n");
+		return -EBUSY;
+	}
+	buff[0] = 0x25; /* to enable alarm_y */
+	buff[1] = 0x20; /* to enable 24-hour format */
+	err = ricoh583_write_regs(dev, rtc_ctrl1, 2, buff);
+	if (err) {
+		dev_err(dev, "failed programming rtc ctrl regs\n");
+		return -EBUSY;
+	}
+return err;
+}
+
+static int ricoh583_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	u8 buff[5];
+	int err;
+
+	err = ricoh583_read_regs(dev, rtc_alarm_y, sizeof(buff), buff);
+	if (err)
+		return err;
+	convert_bcd_to_decimal(buff, sizeof(buff));
+
+	alrm->time.tm_min  = buff[0];
+	alrm->time.tm_hour = buff[1];
+	alrm->time.tm_mday = buff[2];
+	alrm->time.tm_mon  = buff[3];
+	alrm->time.tm_year = buff[4];
+
+	dev_info(dev->parent, "\n getting alarm time::\n");
+	print_time(dev, &alrm->time);
+
+	return 0;
+}
+
+static const struct rtc_class_ops ricoh583_rtc_ops = {
+	.read_time	= ricoh583_rtc_read_time,
+	.set_time	= ricoh583_rtc_set_time,
+	.set_alarm	= ricoh583_rtc_set_alarm,
+	.read_alarm	= ricoh583_rtc_read_alarm,
+};
+
+static irqreturn_t ricoh583_rtc_irq(int irq, void *data)
+{
+	struct device *dev = data;
+	struct ricoh583_rtc *rtc = dev_get_drvdata(dev);
+	u8 reg;
+	int err;
+
+	/* clear alarm-Y status bits.*/
+	err = ricoh583_read_regs(dev, rtc_ctrl2, 1, &reg);
+	if (err) {
+		dev_err(dev->parent, "unable to read rtc_ctrl2 reg\n");
+		return -EBUSY;
+	}
+	reg &= ~0x8;
+	err = ricoh583_write_regs(dev, rtc_ctrl2, 1, &reg);
+	if (err) {
+		dev_err(dev->parent, "unable to program rtc_status reg\n");
+		return -EBUSY;
+	}
+
+	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
+	return IRQ_HANDLED;
+}
+
+static int ricoh583_rtc_probe(struct platform_device *pdev)
+{
+	struct ricoh583_rtc_platform_data *pdata = pdev->dev.platform_data;
+	struct ricoh583_rtc *rtc;
+	struct rtc_time tm;
+	int err;
+	u8 reg[2];
+	rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
+
+	if (!rtc)
+		return -ENOMEM;
+
+	rtc->irq = -1;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "no platform_data specified\n");
+		return -EINVAL;
+	}
+
+	if (pdata->irq < 0)
+		dev_err(&pdev->dev, "\n no irq specified, wakeup is disabled\n");
+
+	dev_set_drvdata(&pdev->dev, rtc);
+	device_init_wakeup(&pdev->dev, 1);
+	rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
+				       &ricoh583_rtc_ops, THIS_MODULE);
+
+	if (IS_ERR(rtc->rtc)) {
+		err = PTR_ERR(rtc->rtc);
+		goto fail;
+	}
+	reg[0] =  0; /* clearing RTC Adjust register */
+	err = ricoh583_write_regs(&pdev->dev, rtc_adjust, 1, reg);
+	if (err) {
+		dev_err(&pdev->dev, "unable to program rtc_adjust reg\n");
+		return -EBUSY;
+	}
+
+	reg[0] = 0x25; /* to enable alarm_y */
+	reg[1] = 0x20; /* to enable 24-hour format */
+	err = ricoh583_write_regs(&pdev->dev, rtc_ctrl1, 2, reg);
+	if (err) {
+		dev_err(&pdev->dev, "failed rtc setup\n");
+		return -EBUSY;
+	}
+
+	ricoh583_rtc_read_time(&pdev->dev, &tm);
+	if ((tm.tm_year < rtc_year_offset || tm.tm_year > (rtc_year_offset + 99))){
+		if (pdata->time.tm_year < 2000 || pdata->time.tm_year > 2100)	{
+			memset(&pdata->time, 0, sizeof(pdata->time));
+			pdata->time.tm_year = rtc_year_offset;
+			pdata->time.tm_mday = 1;
+		} else
+		pdata->time.tm_year -= os_ref_year;
+		ricoh583_rtc_set_time(&pdev->dev, &pdata->time);
+	}
+	if (pdata && (pdata->irq >= 0)) {
+		rtc->irq = pdata->irq;
+		err = request_threaded_irq(pdata->irq, NULL, ricoh583_rtc_irq,
+					IRQF_ONESHOT, "rtc_ricoh583",
+					&pdev->dev);
+		if (err) {
+			dev_err(&pdev->dev, "request IRQ:%d fail\n", rtc->irq);
+			rtc->irq = -1;
+		} else {
+			device_init_wakeup(&pdev->dev, 1);
+			enable_irq_wake(rtc->irq);
+		}
+	}
+	return 0;
+
+fail:
+	if (!IS_ERR_OR_NULL(rtc->rtc))
+		rtc_device_unregister(rtc->rtc);
+	kfree(rtc);
+	return err;
+}
+
+static int ricoh583_rtc_remove(struct platform_device *pdev)
+{
+	struct ricoh583_rtc *rtc = dev_get_drvdata(&pdev->dev);
+
+	if (rtc->irq != -1)
+		free_irq(rtc->irq, rtc);
+	rtc_device_unregister(rtc->rtc);
+	kfree(rtc);
+	return 0;
+}
+
+static struct platform_driver ricoh583_rtc_driver = {
+	.driver	= {
+		.name	= "rtc_ricoh583",
+		.owner	= THIS_MODULE,
+	},
+	.probe	= ricoh583_rtc_probe,
+	.remove	= ricoh583_rtc_remove,
+};
+
+static int __init ricoh583_rtc_init(void)
+{
+	return platform_driver_register(&ricoh583_rtc_driver);
+}
+module_init(ricoh583_rtc_init);
+
+static void __exit ricoh583_rtc_exit(void)
+{
+	platform_driver_unregister(&ricoh583_rtc_driver);
+}
+module_exit(ricoh583_rtc_exit);
+
+MODULE_DESCRIPTION("RICOH PMU ricoh583 RTC driver");
+MODULE_AUTHOR("NVIDIA Corporation");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:rtc_ricoh583");