--- /dev/null
+/*
+ * Real Time Clock driver for Wolfson Microelectronics WM8350
+ *
+ * Copyright (C) 2007, 2008 Wolfson Microelectronics PLC.
+ *
+ * Author: Liam Girdwood
+ * linux@wolfsonmicro.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/module.h>
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/interrupt.h>
+#include <linux/ioctl.h>
+#include <linux/completion.h>
+#include <linux/mfd/wm8350/rtc.h>
+#include <linux/mfd/wm8350/core.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+
+#define WM8350_SET_ALM_RETRIES 5
+#define WM8350_SET_TIME_RETRIES 5
+#define WM8350_GET_TIME_RETRIES 5
+
+#define to_wm8350_from_rtc_dev(d) container_of(d, struct wm8350, rtc.pdev.dev)
+
+/*
+ * Read current time and date in RTC
+ */
+static int wm8350_rtc_readtime(struct device *dev, struct rtc_time *tm)
+{
+ struct wm8350 *wm8350 = dev_get_drvdata(dev);
+ u16 time1[4], time2[4];
+ int retries = WM8350_GET_TIME_RETRIES, ret;
+
+ /*
+ * Read the time twice and compare.
+ * If time1 == time2, then time is valid else retry.
+ */
+ do {
+ ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,
+ 4, time1);
+ if (ret < 0)
+ return ret;
+ ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,
+ 4, time2);
+ if (ret < 0)
+ return ret;
+
+ if (memcmp(time1, time2, sizeof(time1)) == 0) {
+ tm->tm_sec = time1[0] & WM8350_RTC_SECS_MASK;
+
+ tm->tm_min = (time1[0] & WM8350_RTC_MINS_MASK)
+ >> WM8350_RTC_MINS_SHIFT;
+
+ tm->tm_hour = time1[1] & WM8350_RTC_HRS_MASK;
+
+ tm->tm_wday = ((time1[1] >> WM8350_RTC_DAY_SHIFT)
+ & 0x7) - 1;
+
+ tm->tm_mon = ((time1[2] & WM8350_RTC_MTH_MASK)
+ >> WM8350_RTC_MTH_SHIFT) - 1;
+
+ tm->tm_mday = (time1[2] & WM8350_RTC_DATE_MASK);
+
+ tm->tm_year = ((time1[3] & WM8350_RTC_YHUNDREDS_MASK)
+ >> WM8350_RTC_YHUNDREDS_SHIFT) * 100;
+ tm->tm_year += time1[3] & WM8350_RTC_YUNITS_MASK;
+
+ tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon,
+ tm->tm_year);
+ tm->tm_year -= 1900;
+
+ dev_dbg(dev, "Read (%d left): %04x %04x %04x %04x\n",
+ retries,
+ time1[0], time1[1], time1[2], time1[3]);
+
+ return 0;
+ }
+ } while (retries--);
+
+ dev_err(dev, "timed out reading RTC time\n");
+ return -EIO;
+}
+
+/*
+ * Set current time and date in RTC
+ */
+static int wm8350_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+ struct wm8350 *wm8350 = dev_get_drvdata(dev);
+ u16 time[4];
+ u16 rtc_ctrl;
+ int ret, retries = WM8350_SET_TIME_RETRIES;
+
+ time[0] = tm->tm_sec;
+ time[0] |= tm->tm_min << WM8350_RTC_MINS_SHIFT;
+ time[1] = tm->tm_hour;
+ time[1] |= (tm->tm_wday + 1) << WM8350_RTC_DAY_SHIFT;
+ time[2] = tm->tm_mday;
+ time[2] |= (tm->tm_mon + 1) << WM8350_RTC_MTH_SHIFT;
+ time[3] = ((tm->tm_year + 1900) / 100) << WM8350_RTC_YHUNDREDS_SHIFT;
+ time[3] |= (tm->tm_year + 1900) % 100;
+
+ dev_dbg(dev, "Setting: %04x %04x %04x %04x\n",
+ time[0], time[1], time[2], time[3]);
+
+ /* Set RTC_SET to stop the clock */
+ ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL, WM8350_RTC_SET);
+ if (ret < 0)
+ return ret;
+
+ /* Wait until confirmation of stopping */
+ do {
+ rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
+ schedule_timeout_uninterruptible(msecs_to_jiffies(1));
+ } while (--retries && !(rtc_ctrl & WM8350_RTC_STS));
+
+ if (!retries) {
+ dev_err(dev, "timed out on set confirmation\n");
+ return -EIO;
+ }
+
+ /* Write time to RTC */
+ ret = wm8350_block_write(wm8350, WM8350_RTC_SECONDS_MINUTES, 4, time);
+ if (ret < 0)
+ return ret;
+
+ /* Clear RTC_SET to start the clock */
+ ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
+ WM8350_RTC_SET);
+ return ret;
+}
+
+/*
+ * Read alarm time and date in RTC
+ */
+static int wm8350_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct wm8350 *wm8350 = dev_get_drvdata(dev);
+ struct rtc_time *tm = &alrm->time;
+ u16 time[4];
+ int ret;
+
+ ret = wm8350_block_read(wm8350, WM8350_ALARM_SECONDS_MINUTES, 4, time);
+ if (ret < 0)
+ return ret;
+
+ tm->tm_sec = time[0] & WM8350_RTC_ALMSECS_MASK;
+ if (tm->tm_sec == WM8350_RTC_ALMSECS_MASK)
+ tm->tm_sec = -1;
+
+ tm->tm_min = time[0] & WM8350_RTC_ALMMINS_MASK;
+ if (tm->tm_min == WM8350_RTC_ALMMINS_MASK)
+ tm->tm_min = -1;
+ else
+ tm->tm_min >>= WM8350_RTC_ALMMINS_SHIFT;
+
+ tm->tm_hour = time[1] & WM8350_RTC_ALMHRS_MASK;
+ if (tm->tm_hour == WM8350_RTC_ALMHRS_MASK)
+ tm->tm_hour = -1;
+
+ tm->tm_wday = ((time[1] >> WM8350_RTC_ALMDAY_SHIFT) & 0x7) - 1;
+ if (tm->tm_wday > 7)
+ tm->tm_wday = -1;
+
+ tm->tm_mon = time[2] & WM8350_RTC_ALMMTH_MASK;
+ if (tm->tm_mon == WM8350_RTC_ALMMTH_MASK)
+ tm->tm_mon = -1;
+ else
+ tm->tm_mon = (tm->tm_mon >> WM8350_RTC_ALMMTH_SHIFT) - 1;
+
+ tm->tm_mday = (time[2] & WM8350_RTC_ALMDATE_MASK);
+ if (tm->tm_mday == WM8350_RTC_ALMDATE_MASK)
+ tm->tm_mday = -1;
+
+ tm->tm_year = -1;
+
+ alrm->enabled = !(time[3] & WM8350_RTC_ALMSTS);
+
+ return 0;
+}
+
+static int wm8350_rtc_stop_alarm(struct wm8350 *wm8350)
+{
+ int retries = WM8350_SET_ALM_RETRIES;
+ u16 rtc_ctrl;
+ int ret;
+
+ /* Set RTC_SET to stop the clock */
+ ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,
+ WM8350_RTC_ALMSET);
+ if (ret < 0)
+ return ret;
+
+ /* Wait until confirmation of stopping */
+ do {
+ rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
+ schedule_timeout_uninterruptible(msecs_to_jiffies(1));
+ } while (retries-- && !(rtc_ctrl & WM8350_RTC_ALMSTS));
+
+ if (!(rtc_ctrl & WM8350_RTC_ALMSTS))
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static int wm8350_rtc_start_alarm(struct wm8350 *wm8350)
+{
+ int ret;
+ int retries = WM8350_SET_ALM_RETRIES;
+ u16 rtc_ctrl;
+
+ ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
+ WM8350_RTC_ALMSET);
+ if (ret < 0)
+ return ret;
+
+ /* Wait until confirmation */
+ do {
+ rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
+ schedule_timeout_uninterruptible(msecs_to_jiffies(1));
+ } while (retries-- && rtc_ctrl & WM8350_RTC_ALMSTS);
+
+ if (rtc_ctrl & WM8350_RTC_ALMSTS)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static int wm8350_rtc_alarm_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct wm8350 *wm8350 = dev_get_drvdata(dev);
+
+ if (enabled)
+ return wm8350_rtc_start_alarm(wm8350);
+ else
+ return wm8350_rtc_stop_alarm(wm8350);
+}
+
+static int wm8350_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct wm8350 *wm8350 = dev_get_drvdata(dev);
+ struct rtc_time *tm = &alrm->time;
+ u16 time[3];
+ int ret;
+
+ memset(time, 0, sizeof(time));
+
+ if (tm->tm_sec != -1)
+ time[0] |= tm->tm_sec;
+ else
+ time[0] |= WM8350_RTC_ALMSECS_MASK;
+
+ if (tm->tm_min != -1)
+ time[0] |= tm->tm_min << WM8350_RTC_ALMMINS_SHIFT;
+ else
+ time[0] |= WM8350_RTC_ALMMINS_MASK;
+
+ if (tm->tm_hour != -1)
+ time[1] |= tm->tm_hour;
+ else
+ time[1] |= WM8350_RTC_ALMHRS_MASK;
+
+ if (tm->tm_wday != -1)
+ time[1] |= (tm->tm_wday + 1) << WM8350_RTC_ALMDAY_SHIFT;
+ else
+ time[1] |= WM8350_RTC_ALMDAY_MASK;
+
+ if (tm->tm_mday != -1)
+ time[2] |= tm->tm_mday;
+ else
+ time[2] |= WM8350_RTC_ALMDATE_MASK;
+
+ if (tm->tm_mon != -1)
+ time[2] |= (tm->tm_mon + 1) << WM8350_RTC_ALMMTH_SHIFT;
+ else
+ time[2] |= WM8350_RTC_ALMMTH_MASK;
+
+ ret = wm8350_rtc_stop_alarm(wm8350);
+ if (ret < 0)
+ return ret;
+
+ /* Write time to RTC */
+ ret = wm8350_block_write(wm8350, WM8350_ALARM_SECONDS_MINUTES,
+ 3, time);
+ if (ret < 0)
+ return ret;
+
+ if (alrm->enabled)
+ ret = wm8350_rtc_start_alarm(wm8350);
+
+ return ret;
+}
+
+static irqreturn_t wm8350_rtc_alarm_handler(int irq, void *data)
+{
+ struct wm8350 *wm8350 = data;
+ struct rtc_device *rtc = wm8350->rtc.rtc;
+ int ret;
+
+ rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
+
+ /* Make it one shot */
+ ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,
+ WM8350_RTC_ALMSET);
+ if (ret != 0) {
+ dev_err(&(wm8350->rtc.pdev->dev),
+ "Failed to disable alarm: %d\n", ret);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t wm8350_rtc_update_handler(int irq, void *data)
+{
+ struct wm8350 *wm8350 = data;
+ struct rtc_device *rtc = wm8350->rtc.rtc;
+
+ rtc_update_irq(rtc, 1, RTC_IRQF | RTC_UF);
+
+ return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops wm8350_rtc_ops = {
+ .read_time = wm8350_rtc_readtime,
+ .set_time = wm8350_rtc_settime,
+ .read_alarm = wm8350_rtc_readalarm,
+ .set_alarm = wm8350_rtc_setalarm,
+ .alarm_irq_enable = wm8350_rtc_alarm_irq_enable,
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int wm8350_rtc_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct wm8350 *wm8350 = dev_get_drvdata(&pdev->dev);
+ int ret = 0;
+ u16 reg;
+
+ reg = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
+
+ if (device_may_wakeup(&wm8350->rtc.pdev->dev) &&
+ reg & WM8350_RTC_ALMSTS) {
+ ret = wm8350_rtc_stop_alarm(wm8350);
+ if (ret != 0)
+ dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n",
+ ret);
+ }
+
+ return ret;
+}
+
+static int wm8350_rtc_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct wm8350 *wm8350 = dev_get_drvdata(&pdev->dev);
+ int ret;
+
+ if (wm8350->rtc.alarm_enabled) {
+ ret = wm8350_rtc_start_alarm(wm8350);
+ if (ret != 0)
+ dev_err(&pdev->dev,
+ "Failed to restart RTC alarm: %d\n", ret);
+ }
+
+ return 0;
+}
+#endif
+
+static int wm8350_rtc_probe(struct platform_device *pdev)
+{
+ struct wm8350 *wm8350 = platform_get_drvdata(pdev);
+ struct wm8350_rtc *wm_rtc = &wm8350->rtc;
+ int ret = 0;
+ u16 timectl, power5;
+
+ timectl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
+ if (timectl & WM8350_RTC_BCD) {
+ dev_err(&pdev->dev, "RTC BCD mode not supported\n");
+ return -EINVAL;
+ }
+ if (timectl & WM8350_RTC_12HR) {
+ dev_err(&pdev->dev, "RTC 12 hour mode not supported\n");
+ return -EINVAL;
+ }
+
+ /* enable the RTC if it's not already enabled */
+ power5 = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5);
+ if (!(power5 & WM8350_RTC_TICK_ENA)) {
+ dev_info(wm8350->dev, "Starting RTC\n");
+
+ wm8350_reg_unlock(wm8350);
+
+ ret = wm8350_set_bits(wm8350, WM8350_POWER_MGMT_5,
+ WM8350_RTC_TICK_ENA);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to enable RTC: %d\n", ret);
+ return ret;
+ }
+
+ wm8350_reg_lock(wm8350);
+ }
+
+ if (timectl & WM8350_RTC_STS) {
+ int retries;
+
+ ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
+ WM8350_RTC_SET);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to start: %d\n", ret);
+ return ret;
+ }
+
+ retries = WM8350_SET_TIME_RETRIES;
+ do {
+ timectl = wm8350_reg_read(wm8350,
+ WM8350_RTC_TIME_CONTROL);
+ } while (timectl & WM8350_RTC_STS && --retries);
+
+ if (retries == 0) {
+ dev_err(&pdev->dev, "failed to start: timeout\n");
+ return -ENODEV;
+ }
+ }
+
+ device_init_wakeup(&pdev->dev, 1);
+
+ wm_rtc->rtc = devm_rtc_device_register(&pdev->dev, "wm8350",
+ &wm8350_rtc_ops, THIS_MODULE);
+ if (IS_ERR(wm_rtc->rtc)) {
+ ret = PTR_ERR(wm_rtc->rtc);
+ dev_err(&pdev->dev, "failed to register RTC: %d\n", ret);
+ return ret;
+ }
+
+ wm8350_register_irq(wm8350, WM8350_IRQ_RTC_SEC,
+ wm8350_rtc_update_handler, 0,
+ "RTC Seconds", wm8350);
+ wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC);
+
+ wm8350_register_irq(wm8350, WM8350_IRQ_RTC_ALM,
+ wm8350_rtc_alarm_handler, 0,
+ "RTC Alarm", wm8350);
+
+ return 0;
+}
+
+static int wm8350_rtc_remove(struct platform_device *pdev)
+{
+ struct wm8350 *wm8350 = platform_get_drvdata(pdev);
+
+ wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350);
+ wm8350_free_irq(wm8350, WM8350_IRQ_RTC_ALM, wm8350);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(wm8350_rtc_pm_ops, wm8350_rtc_suspend,
+ wm8350_rtc_resume);
+
+static struct platform_driver wm8350_rtc_driver = {
+ .probe = wm8350_rtc_probe,
+ .remove = wm8350_rtc_remove,
+ .driver = {
+ .name = "wm8350-rtc",
+ .pm = &wm8350_rtc_pm_ops,
+ },
+};
+
+module_platform_driver(wm8350_rtc_driver);
+
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("RTC driver for the WM8350");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm8350-rtc");
Code Review / kvmfornfv.git / blobdiff