Initial import

1 files changed, 532 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ab8500.c b/drivers/rtc/rtc-ab8500.c
new file mode 100644
index 000000000..6856f0a3a
--- /dev/null
+++ b/drivers/rtc/rtc-ab8500.c
@@ -0,0 +1,532 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ * Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
+ *
+ * RTC clock driver for the RTC part of the AB8500 Power management chip.
+ * Based on RTC clock driver for the AB3100 Analog Baseband Chip by
+ * Linus Walleij <linus.walleij@stericsson.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/mfd/abx500.h>
+#include <linux/mfd/abx500/ab8500.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+
+#define AB8500_RTC_SOFF_STAT_REG	0x00
+#define AB8500_RTC_CC_CONF_REG		0x01
+#define AB8500_RTC_READ_REQ_REG		0x02
+#define AB8500_RTC_WATCH_TSECMID_REG	0x03
+#define AB8500_RTC_WATCH_TSECHI_REG	0x04
+#define AB8500_RTC_WATCH_TMIN_LOW_REG	0x05
+#define AB8500_RTC_WATCH_TMIN_MID_REG	0x06
+#define AB8500_RTC_WATCH_TMIN_HI_REG	0x07
+#define AB8500_RTC_ALRM_MIN_LOW_REG	0x08
+#define AB8500_RTC_ALRM_MIN_MID_REG	0x09
+#define AB8500_RTC_ALRM_MIN_HI_REG	0x0A
+#define AB8500_RTC_STAT_REG		0x0B
+#define AB8500_RTC_BKUP_CHG_REG		0x0C
+#define AB8500_RTC_FORCE_BKUP_REG	0x0D
+#define AB8500_RTC_CALIB_REG		0x0E
+#define AB8500_RTC_SWITCH_STAT_REG	0x0F
+#define AB8540_RTC_ALRM_SEC		0x22
+#define AB8540_RTC_ALRM_MIN_LOW_REG	0x23
+#define AB8540_RTC_ALRM_MIN_MID_REG	0x24
+#define AB8540_RTC_ALRM_MIN_HI_REG	0x25
+
+/* RtcReadRequest bits */
+#define RTC_READ_REQUEST		0x01
+#define RTC_WRITE_REQUEST		0x02
+
+/* RtcCtrl bits */
+#define RTC_ALARM_ENA			0x04
+#define RTC_STATUS_DATA			0x01
+
+#define COUNTS_PER_SEC			(0xF000 / 60)
+#define AB8500_RTC_EPOCH		2000
+
+static const u8 ab8500_rtc_time_regs[] = {
+	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
+	AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
+	AB8500_RTC_WATCH_TSECMID_REG
+};
+
+static const u8 ab8500_rtc_alarm_regs[] = {
+	AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
+	AB8500_RTC_ALRM_MIN_LOW_REG
+};
+
+static const u8 ab8540_rtc_alarm_regs[] = {
+	AB8540_RTC_ALRM_MIN_HI_REG, AB8540_RTC_ALRM_MIN_MID_REG,
+	AB8540_RTC_ALRM_MIN_LOW_REG, AB8540_RTC_ALRM_SEC
+};
+
+/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
+static unsigned long get_elapsed_seconds(int year)
+{
+	unsigned long secs;
+	struct rtc_time tm = {
+		.tm_year = year - 1900,
+		.tm_mday = 1,
+	};
+
+	/*
+	 * This function calculates secs from 1970 and not from
+	 * 1900, even if we supply the offset from year 1900.
+	 */
+	rtc_tm_to_time(&tm, &secs);
+	return secs;
+}
+
+static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned long timeout = jiffies + HZ;
+	int retval, i;
+	unsigned long mins, secs;
+	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
+	u8 value;
+
+	/* Request a data read */
+	retval = abx500_set_register_interruptible(dev,
+		AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
+	if (retval < 0)
+		return retval;
+
+	/* Wait for some cycles after enabling the rtc read in ab8500 */
+	while (time_before(jiffies, timeout)) {
+		retval = abx500_get_register_interruptible(dev,
+			AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
+		if (retval < 0)
+			return retval;
+
+		if (!(value & RTC_READ_REQUEST))
+			break;
+
+		usleep_range(1000, 5000);
+	}
+
+	/* Read the Watchtime registers */
+	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
+		retval = abx500_get_register_interruptible(dev,
+			AB8500_RTC, ab8500_rtc_time_regs[i], &value);
+		if (retval < 0)
+			return retval;
+		buf[i] = value;
+	}
+
+	mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
+
+	secs =	(buf[3] << 8) | buf[4];
+	secs =	secs / COUNTS_PER_SEC;
+	secs =	secs + (mins * 60);
+
+	/* Add back the initially subtracted number of seconds */
+	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
+
+	rtc_time_to_tm(secs, tm);
+	return rtc_valid_tm(tm);
+}
+
+static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	int retval, i;
+	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
+	unsigned long no_secs, no_mins, secs = 0;
+
+	if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
+		dev_dbg(dev, "year should be equal to or greater than %d\n",
+				AB8500_RTC_EPOCH);
+		return -EINVAL;
+	}
+
+	/* Get the number of seconds since 1970 */
+	rtc_tm_to_time(tm, &secs);
+
+	/*
+	 * Convert it to the number of seconds since 01-01-2000 00:00:00, since
+	 * we only have a small counter in the RTC.
+	 */
+	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
+
+	no_mins = secs / 60;
+
+	no_secs = secs % 60;
+	/* Make the seconds count as per the RTC resolution */
+	no_secs = no_secs * COUNTS_PER_SEC;
+
+	buf[4] = no_secs & 0xFF;
+	buf[3] = (no_secs >> 8) & 0xFF;
+
+	buf[2] = no_mins & 0xFF;
+	buf[1] = (no_mins >> 8) & 0xFF;
+	buf[0] = (no_mins >> 16) & 0xFF;
+
+	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
+		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
+			ab8500_rtc_time_regs[i], buf[i]);
+		if (retval < 0)
+			return retval;
+	}
+
+	/* Request a data write */
+	return abx500_set_register_interruptible(dev, AB8500_RTC,
+		AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
+}
+
+static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	int retval, i;
+	u8 rtc_ctrl, value;
+	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
+	unsigned long secs, mins;
+
+	/* Check if the alarm is enabled or not */
+	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
+		AB8500_RTC_STAT_REG, &rtc_ctrl);
+	if (retval < 0)
+		return retval;
+
+	if (rtc_ctrl & RTC_ALARM_ENA)
+		alarm->enabled = 1;
+	else
+		alarm->enabled = 0;
+
+	alarm->pending = 0;
+
+	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
+		retval = abx500_get_register_interruptible(dev, AB8500_RTC,
+			ab8500_rtc_alarm_regs[i], &value);
+		if (retval < 0)
+			return retval;
+		buf[i] = value;
+	}
+
+	mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
+	secs = mins * 60;
+
+	/* Add back the initially subtracted number of seconds */
+	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
+
+	rtc_time_to_tm(secs, &alarm->time);
+
+	return rtc_valid_tm(&alarm->time);
+}
+
+static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
+{
+	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
+		AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
+		enabled ? RTC_ALARM_ENA : 0);
+}
+
+static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	int retval, i;
+	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
+	unsigned long mins, secs = 0, cursec = 0;
+	struct rtc_time curtm;
+
+	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
+		dev_dbg(dev, "year should be equal to or greater than %d\n",
+				AB8500_RTC_EPOCH);
+		return -EINVAL;
+	}
+
+	/* Get the number of seconds since 1970 */
+	rtc_tm_to_time(&alarm->time, &secs);
+
+	/*
+	 * Check whether alarm is set less than 1min.
+	 * Since our RTC doesn't support alarm resolution less than 1min,
+	 * return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
+	 */
+	ab8500_rtc_read_time(dev, &curtm); /* Read current time */
+	rtc_tm_to_time(&curtm, &cursec);
+	if ((secs - cursec) < 59) {
+		dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Convert it to the number of seconds since 01-01-2000 00:00:00, since
+	 * we only have a small counter in the RTC.
+	 */
+	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
+
+	mins = secs / 60;
+
+	buf[2] = mins & 0xFF;
+	buf[1] = (mins >> 8) & 0xFF;
+	buf[0] = (mins >> 16) & 0xFF;
+
+	/* Set the alarm time */
+	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
+		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
+			ab8500_rtc_alarm_regs[i], buf[i]);
+		if (retval < 0)
+			return retval;
+	}
+
+	return ab8500_rtc_irq_enable(dev, alarm->enabled);
+}
+
+static int ab8540_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	int retval, i;
+	unsigned char buf[ARRAY_SIZE(ab8540_rtc_alarm_regs)];
+	unsigned long mins, secs = 0;
+
+	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
+		dev_dbg(dev, "year should be equal to or greater than %d\n",
+				AB8500_RTC_EPOCH);
+		return -EINVAL;
+	}
+
+	/* Get the number of seconds since 1970 */
+	rtc_tm_to_time(&alarm->time, &secs);
+
+	/*
+	 * Convert it to the number of seconds since 01-01-2000 00:00:00
+	 */
+	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
+	mins = secs / 60;
+
+	buf[3] = secs % 60;
+	buf[2] = mins & 0xFF;
+	buf[1] = (mins >> 8) & 0xFF;
+	buf[0] = (mins >> 16) & 0xFF;
+
+	/* Set the alarm time */
+	for (i = 0; i < ARRAY_SIZE(ab8540_rtc_alarm_regs); i++) {
+		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
+			ab8540_rtc_alarm_regs[i], buf[i]);
+		if (retval < 0)
+			return retval;
+	}
+
+	return ab8500_rtc_irq_enable(dev, alarm->enabled);
+}
+
+static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
+{
+	int retval;
+	u8  rtccal = 0;
+
+	/*
+	 * Check that the calibration value (which is in units of 0.5
+	 * parts-per-million) is in the AB8500's range for RtcCalibration
+	 * register. -128 (0x80) is not permitted because the AB8500 uses
+	 * a sign-bit rather than two's complement, so 0x80 is just another
+	 * representation of zero.
+	 */
+	if ((calibration < -127) || (calibration > 127)) {
+		dev_err(dev, "RtcCalibration value outside permitted range\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
+	 * so need to convert to this sort of representation before writing
+	 * into RtcCalibration register...
+	 */
+	if (calibration >= 0)
+		rtccal = 0x7F & calibration;
+	else
+		rtccal = ~(calibration - 1) | 0x80;
+
+	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
+			AB8500_RTC_CALIB_REG, rtccal);
+
+	return retval;
+}
+
+static int ab8500_rtc_get_calibration(struct device *dev, int *calibration)
+{
+	int retval;
+	u8  rtccal = 0;
+
+	retval =  abx500_get_register_interruptible(dev, AB8500_RTC,
+			AB8500_RTC_CALIB_REG, &rtccal);
+	if (retval >= 0) {
+		/*
+		 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
+		 * so need to convert value from RtcCalibration register into
+		 * a two's complement signed value...
+		 */
+		if (rtccal & 0x80)
+			*calibration = 0 - (rtccal & 0x7F);
+		else
+			*calibration = 0x7F & rtccal;
+	}
+
+	return retval;
+}
+
+static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	int retval;
+	int calibration = 0;
+
+	if (sscanf(buf, " %i ", &calibration) != 1) {
+		dev_err(dev, "Failed to store RTC calibration attribute\n");
+		return -EINVAL;
+	}
+
+	retval = ab8500_rtc_set_calibration(dev, calibration);
+
+	return retval ? retval : count;
+}
+
+static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	int  retval = 0;
+	int  calibration = 0;
+
+	retval = ab8500_rtc_get_calibration(dev, &calibration);
+	if (retval < 0) {
+		dev_err(dev, "Failed to read RTC calibration attribute\n");
+		sprintf(buf, "0\n");
+		return retval;
+	}
+
+	return sprintf(buf, "%d\n", calibration);
+}
+
+static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,
+		   ab8500_sysfs_show_rtc_calibration,
+		   ab8500_sysfs_store_rtc_calibration);
+
+static int ab8500_sysfs_rtc_register(struct device *dev)
+{
+	return device_create_file(dev, &dev_attr_rtc_calibration);
+}
+
+static void ab8500_sysfs_rtc_unregister(struct device *dev)
+{
+	device_remove_file(dev, &dev_attr_rtc_calibration);
+}
+
+static irqreturn_t rtc_alarm_handler(int irq, void *data)
+{
+	struct rtc_device *rtc = data;
+	unsigned long events = RTC_IRQF | RTC_AF;
+
+	dev_dbg(&rtc->dev, "%s\n", __func__);
+	rtc_update_irq(rtc, 1, events);
+
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops ab8500_rtc_ops = {
+	.read_time		= ab8500_rtc_read_time,
+	.set_time		= ab8500_rtc_set_time,
+	.read_alarm		= ab8500_rtc_read_alarm,
+	.set_alarm		= ab8500_rtc_set_alarm,
+	.alarm_irq_enable	= ab8500_rtc_irq_enable,
+};
+
+static const struct rtc_class_ops ab8540_rtc_ops = {
+	.read_time		= ab8500_rtc_read_time,
+	.set_time		= ab8500_rtc_set_time,
+	.read_alarm		= ab8500_rtc_read_alarm,
+	.set_alarm		= ab8540_rtc_set_alarm,
+	.alarm_irq_enable	= ab8500_rtc_irq_enable,
+};
+
+static struct platform_device_id ab85xx_rtc_ids[] = {
+	{ "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
+	{ "ab8540-rtc", (kernel_ulong_t)&ab8540_rtc_ops, },
+};
+
+static int ab8500_rtc_probe(struct platform_device *pdev)
+{
+	const struct platform_device_id *platid = platform_get_device_id(pdev);
+	int err;
+	struct rtc_device *rtc;
+	u8 rtc_ctrl;
+	int irq;
+
+	irq = platform_get_irq_byname(pdev, "ALARM");
+	if (irq < 0)
+		return irq;
+
+	/* For RTC supply test */
+	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
+		AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
+	if (err < 0)
+		return err;
+
+	/* Wait for reset by the PorRtc */
+	usleep_range(1000, 5000);
+
+	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
+		AB8500_RTC_STAT_REG, &rtc_ctrl);
+	if (err < 0)
+		return err;
+
+	/* Check if the RTC Supply fails */
+	if (!(rtc_ctrl & RTC_STATUS_DATA)) {
+		dev_err(&pdev->dev, "RTC supply failure\n");
+		return -ENODEV;
+	}
+
+	device_init_wakeup(&pdev->dev, true);
+
+	rtc = devm_rtc_device_register(&pdev->dev, "ab8500-rtc",
+				(struct rtc_class_ops *)platid->driver_data,
+				THIS_MODULE);
+	if (IS_ERR(rtc)) {
+		dev_err(&pdev->dev, "Registration failed\n");
+		err = PTR_ERR(rtc);
+		return err;
+	}
+
+	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+			rtc_alarm_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
+			"ab8500-rtc", rtc);
+	if (err < 0)
+		return err;
+
+	platform_set_drvdata(pdev, rtc);
+
+	err = ab8500_sysfs_rtc_register(&pdev->dev);
+	if (err) {
+		dev_err(&pdev->dev, "sysfs RTC failed to register\n");
+		return err;
+	}
+
+	rtc->uie_unsupported = 1;
+
+	return 0;
+}
+
+static int ab8500_rtc_remove(struct platform_device *pdev)
+{
+	ab8500_sysfs_rtc_unregister(&pdev->dev);
+
+	return 0;
+}
+
+static struct platform_driver ab8500_rtc_driver = {
+	.driver = {
+		.name = "ab8500-rtc",
+	},
+	.probe	= ab8500_rtc_probe,
+	.remove = ab8500_rtc_remove,
+	.id_table = ab85xx_rtc_ids,
+};
+
+module_platform_driver(ab8500_rtc_driver);
+
+MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
+MODULE_DESCRIPTION("AB8500 RTC Driver");
+MODULE_LICENSE("GPL v2");