--- /dev/null
+/*
+ * 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");
Code Review / kvmfornfv.git / blobdiff