1 files changed, 475 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c
new file mode 100644
index 000000000..9f10af7ac
--- /dev/null
+++ b/drivers/rtc/rtc-tps65910.c
@@ -0,0 +1,475 @@
+/*
+ * rtc-tps65910.c -- TPS65910 Real Time Clock interface
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ * Author: Venu Byravarasu <vbyravarasu@nvidia.com>
+ *
+ * Based on original TI driver rtc-twl.c
+ *   Copyright (C) 2007 MontaVista Software, Inc
+ *   Author: Alexandre Rusev <source@mvista.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/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/math64.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/tps65910.h>
+
+struct tps65910_rtc {
+	struct rtc_device	*rtc;
+	int irq;
+};
+
+/* Total number of RTC registers needed to set time*/
+#define NUM_TIME_REGS	(TPS65910_YEARS - TPS65910_SECONDS + 1)
+
+/* Total number of RTC registers needed to set compensation registers */
+#define NUM_COMP_REGS	(TPS65910_RTC_COMP_MSB - TPS65910_RTC_COMP_LSB + 1)
+
+/* Min and max values supported with 'offset' interface (swapped sign) */
+#define MIN_OFFSET	(-277761)
+#define MAX_OFFSET	(277778)
+
+/* Number of ticks per hour */
+#define TICKS_PER_HOUR	(32768 * 3600)
+
+/* Multiplier for ppb conversions */
+#define PPB_MULT	(1000000000LL)
+
+static int tps65910_rtc_alarm_irq_enable(struct device *dev,
+					 unsigned int enabled)
+{
+	struct tps65910 *tps = dev_get_drvdata(dev->parent);
+	u8 val = 0;
+
+	if (enabled)
+		val = TPS65910_RTC_INTERRUPTS_IT_ALARM;
+
+	return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val);
+}
+
+/*
+ * Gets current tps65910 RTC time and date parameters.
+ *
+ * The RTC's time/alarm representation is not what gmtime(3) requires
+ * Linux to use:
+ *
+ *  - Months are 1..12 vs Linux 0-11
+ *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
+ */
+static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned char rtc_data[NUM_TIME_REGS];
+	struct tps65910 *tps = dev_get_drvdata(dev->parent);
+	int ret;
+
+	/* Copy RTC counting registers to static registers or latches */
+	ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
+		TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME);
+	if (ret < 0) {
+		dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data,
+		NUM_TIME_REGS);
+	if (ret < 0) {
+		dev_err(dev, "reading from RTC failed with err:%d\n", ret);
+		return ret;
+	}
+
+	tm->tm_sec = bcd2bin(rtc_data[0]);
+	tm->tm_min = bcd2bin(rtc_data[1]);
+	tm->tm_hour = bcd2bin(rtc_data[2]);
+	tm->tm_mday = bcd2bin(rtc_data[3]);
+	tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
+	tm->tm_year = bcd2bin(rtc_data[5]) + 100;
+
+	return ret;
+}
+
+static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned char rtc_data[NUM_TIME_REGS];
+	struct tps65910 *tps = dev_get_drvdata(dev->parent);
+	int ret;
+
+	rtc_data[0] = bin2bcd(tm->tm_sec);
+	rtc_data[1] = bin2bcd(tm->tm_min);
+	rtc_data[2] = bin2bcd(tm->tm_hour);
+	rtc_data[3] = bin2bcd(tm->tm_mday);
+	rtc_data[4] = bin2bcd(tm->tm_mon + 1);
+	rtc_data[5] = bin2bcd(tm->tm_year - 100);
+
+	/* Stop RTC while updating the RTC time registers */
+	ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
+		TPS65910_RTC_CTRL_STOP_RTC, 0);
+	if (ret < 0) {
+		dev_err(dev, "RTC stop failed with err:%d\n", ret);
+		return ret;
+	}
+
+	/* update all the time registers in one shot */
+	ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data,
+		NUM_TIME_REGS);
+	if (ret < 0) {
+		dev_err(dev, "rtc_set_time error %d\n", ret);
+		return ret;
+	}
+
+	/* Start back RTC */
+	ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
+		TPS65910_RTC_CTRL_STOP_RTC, 1);
+	if (ret < 0)
+		dev_err(dev, "RTC start failed with err:%d\n", ret);
+
+	return ret;
+}
+
+/*
+ * Gets current tps65910 RTC alarm time.
+ */
+static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	unsigned char alarm_data[NUM_TIME_REGS];
+	u32 int_val;
+	struct tps65910 *tps = dev_get_drvdata(dev->parent);
+	int ret;
+
+	ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, alarm_data,
+		NUM_TIME_REGS);
+	if (ret < 0) {
+		dev_err(dev, "rtc_read_alarm error %d\n", ret);
+		return ret;
+	}
+
+	alm->time.tm_sec = bcd2bin(alarm_data[0]);
+	alm->time.tm_min = bcd2bin(alarm_data[1]);
+	alm->time.tm_hour = bcd2bin(alarm_data[2]);
+	alm->time.tm_mday = bcd2bin(alarm_data[3]);
+	alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
+	alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
+
+	ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val);
+	if (ret < 0)
+		return ret;
+
+	if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM)
+		alm->enabled = 1;
+
+	return ret;
+}
+
+static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	unsigned char alarm_data[NUM_TIME_REGS];
+	struct tps65910 *tps = dev_get_drvdata(dev->parent);
+	int ret;
+
+	ret = tps65910_rtc_alarm_irq_enable(dev, 0);
+	if (ret)
+		return ret;
+
+	alarm_data[0] = bin2bcd(alm->time.tm_sec);
+	alarm_data[1] = bin2bcd(alm->time.tm_min);
+	alarm_data[2] = bin2bcd(alm->time.tm_hour);
+	alarm_data[3] = bin2bcd(alm->time.tm_mday);
+	alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
+	alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
+
+	/* update all the alarm registers in one shot */
+	ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS,
+		alarm_data, NUM_TIME_REGS);
+	if (ret) {
+		dev_err(dev, "rtc_set_alarm error %d\n", ret);
+		return ret;
+	}
+
+	if (alm->enabled)
+		ret = tps65910_rtc_alarm_irq_enable(dev, 1);
+
+	return ret;
+}
+
+static int tps65910_rtc_set_calibration(struct device *dev, int calibration)
+{
+	unsigned char comp_data[NUM_COMP_REGS];
+	struct tps65910 *tps = dev_get_drvdata(dev->parent);
+	s16 value;
+	int ret;
+
+	/*
+	 * TPS65910 uses two's complement 16 bit value for compensation for RTC
+	 * crystal inaccuracies. One time every hour when seconds counter
+	 * increments from 0 to 1 compensation value will be added to internal
+	 * RTC counter value.
+	 *
+	 * Compensation value 0x7FFF is prohibited value.
+	 *
+	 * Valid range for compensation value: [-32768 .. 32766]
+	 */
+	if ((calibration < -32768) || (calibration > 32766)) {
+		dev_err(dev, "RTC calibration value out of range: %d\n",
+			calibration);
+		return -EINVAL;
+	}
+
+	value = (s16)calibration;
+
+	comp_data[0] = (u16)value & 0xFF;
+	comp_data[1] = ((u16)value >> 8) & 0xFF;
+
+	/* Update all the compensation registers in one shot */
+	ret = regmap_bulk_write(tps->regmap, TPS65910_RTC_COMP_LSB,
+		comp_data, NUM_COMP_REGS);
+	if (ret < 0) {
+		dev_err(dev, "rtc_set_calibration error: %d\n", ret);
+		return ret;
+	}
+
+	/* Enable automatic compensation */
+	ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
+		TPS65910_RTC_CTRL_AUTO_COMP, TPS65910_RTC_CTRL_AUTO_COMP);
+	if (ret < 0)
+		dev_err(dev, "auto_comp enable failed with error: %d\n", ret);
+
+	return ret;
+}
+
+static int tps65910_rtc_get_calibration(struct device *dev, int *calibration)
+{
+	unsigned char comp_data[NUM_COMP_REGS];
+	struct tps65910 *tps = dev_get_drvdata(dev->parent);
+	unsigned int ctrl;
+	u16 value;
+	int ret;
+
+	ret = regmap_read(tps->regmap, TPS65910_RTC_CTRL, &ctrl);
+	if (ret < 0)
+		return ret;
+
+	/* If automatic compensation is not enabled report back zero */
+	if (!(ctrl & TPS65910_RTC_CTRL_AUTO_COMP)) {
+		*calibration = 0;
+		return 0;
+	}
+
+	ret = regmap_bulk_read(tps->regmap, TPS65910_RTC_COMP_LSB, comp_data,
+		NUM_COMP_REGS);
+	if (ret < 0) {
+		dev_err(dev, "rtc_get_calibration error: %d\n", ret);
+		return ret;
+	}
+
+	value = (u16)comp_data[0] | ((u16)comp_data[1] << 8);
+
+	*calibration = (s16)value;
+
+	return 0;
+}
+
+static int tps65910_read_offset(struct device *dev, long *offset)
+{
+	int calibration;
+	s64 tmp;
+	int ret;
+
+	ret = tps65910_rtc_get_calibration(dev, &calibration);
+	if (ret < 0)
+		return ret;
+
+	/* Convert from RTC calibration register format to ppb format */
+	tmp = calibration * (s64)PPB_MULT;
+	if (tmp < 0)
+		tmp -= TICKS_PER_HOUR / 2LL;
+	else
+		tmp += TICKS_PER_HOUR / 2LL;
+	tmp = div_s64(tmp, TICKS_PER_HOUR);
+
+	/* Offset value operates in negative way, so swap sign */
+	*offset = (long)-tmp;
+
+	return 0;
+}
+
+static int tps65910_set_offset(struct device *dev, long offset)
+{
+	int calibration;
+	s64 tmp;
+	int ret;
+
+	/* Make sure offset value is within supported range */
+	if (offset < MIN_OFFSET || offset > MAX_OFFSET)
+		return -ERANGE;
+
+	/* Convert from ppb format to RTC calibration register format */
+	tmp = offset * (s64)TICKS_PER_HOUR;
+	if (tmp < 0)
+		tmp -= PPB_MULT / 2LL;
+	else
+		tmp += PPB_MULT / 2LL;
+	tmp = div_s64(tmp, PPB_MULT);
+
+	/* Offset value operates in negative way, so swap sign */
+	calibration = (int)-tmp;
+
+	ret = tps65910_rtc_set_calibration(dev, calibration);
+
+	return ret;
+}
+
+static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc)
+{
+	struct device *dev = rtc;
+	unsigned long events = 0;
+	struct tps65910 *tps = dev_get_drvdata(dev->parent);
+	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
+	int ret;
+	u32 rtc_reg;
+
+	ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg);
+	if (ret)
+		return IRQ_NONE;
+
+	if (rtc_reg & TPS65910_RTC_STATUS_ALARM)
+		events = RTC_IRQF | RTC_AF;
+
+	ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg);
+	if (ret)
+		return IRQ_NONE;
+
+	/* Notify RTC core on event */
+	rtc_update_irq(tps_rtc->rtc, 1, events);
+
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops tps65910_rtc_ops = {
+	.read_time	= tps65910_rtc_read_time,
+	.set_time	= tps65910_rtc_set_time,
+	.read_alarm	= tps65910_rtc_read_alarm,
+	.set_alarm	= tps65910_rtc_set_alarm,
+	.alarm_irq_enable = tps65910_rtc_alarm_irq_enable,
+	.read_offset	= tps65910_read_offset,
+	.set_offset	= tps65910_set_offset,
+};
+
+static int tps65910_rtc_probe(struct platform_device *pdev)
+{
+	struct tps65910 *tps65910 = NULL;
+	struct tps65910_rtc *tps_rtc = NULL;
+	int ret;
+	int irq;
+	u32 rtc_reg;
+
+	tps65910 = dev_get_drvdata(pdev->dev.parent);
+
+	tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc),
+			GFP_KERNEL);
+	if (!tps_rtc)
+		return -ENOMEM;
+
+	tps_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(tps_rtc->rtc))
+		return PTR_ERR(tps_rtc->rtc);
+
+	/* Clear pending interrupts */
+	ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg);
+	if (ret < 0)
+		return ret;
+
+	dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n");
+
+	/* Enable RTC digital power domain */
+	ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL,
+		DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT);
+	if (ret < 0)
+		return ret;
+
+	rtc_reg = TPS65910_RTC_CTRL_STOP_RTC;
+	ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, tps_rtc);
+
+	irq  = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n",
+			irq);
+		return -ENXIO;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+		tps65910_rtc_interrupt, IRQF_TRIGGER_LOW,
+		dev_name(&pdev->dev), &pdev->dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "IRQ is not free.\n");
+		return ret;
+	}
+	tps_rtc->irq = irq;
+	device_set_wakeup_capable(&pdev->dev, 1);
+
+	tps_rtc->rtc->ops = &tps65910_rtc_ops;
+	tps_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	tps_rtc->rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+	ret = rtc_register_device(tps_rtc->rtc);
+	if (ret) {
+		dev_err(&pdev->dev, "RTC device register: err %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tps65910_rtc_suspend(struct device *dev)
+{
+	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(tps_rtc->irq);
+	return 0;
+}
+
+static int tps65910_rtc_resume(struct device *dev)
+{
+	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(tps_rtc->irq);
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(tps65910_rtc_pm_ops, tps65910_rtc_suspend,
+			tps65910_rtc_resume);
+
+static struct platform_driver tps65910_rtc_driver = {
+	.probe		= tps65910_rtc_probe,
+	.driver		= {
+		.name	= "tps65910-rtc",
+		.pm	= &tps65910_rtc_pm_ops,
+	},
+};
+
+module_platform_driver(tps65910_rtc_driver);
+MODULE_ALIAS("platform:tps65910-rtc");
+MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
+MODULE_LICENSE("GPL");