/* * 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 /* * 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");