diff options
Diffstat (limited to 'drivers/rtc/rtc-wm8350.c')
| -rw-r--r-- | drivers/rtc/rtc-wm8350.c | 481 |
1 files changed, 481 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-wm8350.c b/drivers/rtc/rtc-wm8350.c new file mode 100644 index 000000000..6eaa9321c --- /dev/null +++ b/drivers/rtc/rtc-wm8350.c @@ -0,0 +1,481 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Real Time Clock driver for Wolfson Microelectronics WM8350 + * + * Copyright (C) 2007, 2008 Wolfson Microelectronics PLC. + * + * Author: Liam Girdwood + * linux@wolfsonmicro.com + */ + +#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 wm8350 *wm8350 = dev_get_drvdata(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(dev, "Failed to stop RTC alarm: %d\n", ret); + } + + return ret; +} + +static int wm8350_rtc_resume(struct device *dev) +{ + struct wm8350 *wm8350 = dev_get_drvdata(dev); + int ret; + + if (wm8350->rtc.alarm_enabled) { + ret = wm8350_rtc_start_alarm(wm8350); + if (ret != 0) + dev_err(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; + } + + ret = wm8350_register_irq(wm8350, WM8350_IRQ_RTC_SEC, + wm8350_rtc_update_handler, 0, + "RTC Seconds", wm8350); + if (ret) + return ret; + + wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC); + + ret = wm8350_register_irq(wm8350, WM8350_IRQ_RTC_ALM, + wm8350_rtc_alarm_handler, 0, + "RTC Alarm", wm8350); + if (ret) { + wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350); + return ret; + } + + 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"); |