diff options
Diffstat (limited to 'drivers/rtc/rtc-spear.c')
| -rw-r--r-- | drivers/rtc/rtc-spear.c | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-spear.c b/drivers/rtc/rtc-spear.c new file mode 100644 index 000000000..d2cdb9823 --- /dev/null +++ b/drivers/rtc/rtc-spear.c @@ -0,0 +1,509 @@ +/* + * drivers/rtc/rtc-spear.c + * + * Copyright (C) 2010 ST Microelectronics + * Rajeev Kumar<rajeev-dlh.kumar@st.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/bcd.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +/* RTC registers */ +#define TIME_REG 0x00 +#define DATE_REG 0x04 +#define ALARM_TIME_REG 0x08 +#define ALARM_DATE_REG 0x0C +#define CTRL_REG 0x10 +#define STATUS_REG 0x14 + +/* TIME_REG & ALARM_TIME_REG */ +#define SECONDS_UNITS (0xf<<0) /* seconds units position */ +#define SECONDS_TENS (0x7<<4) /* seconds tens position */ +#define MINUTES_UNITS (0xf<<8) /* minutes units position */ +#define MINUTES_TENS (0x7<<12) /* minutes tens position */ +#define HOURS_UNITS (0xf<<16) /* hours units position */ +#define HOURS_TENS (0x3<<20) /* hours tens position */ + +/* DATE_REG & ALARM_DATE_REG */ +#define DAYS_UNITS (0xf<<0) /* days units position */ +#define DAYS_TENS (0x3<<4) /* days tens position */ +#define MONTHS_UNITS (0xf<<8) /* months units position */ +#define MONTHS_TENS (0x1<<12) /* months tens position */ +#define YEARS_UNITS (0xf<<16) /* years units position */ +#define YEARS_TENS (0xf<<20) /* years tens position */ +#define YEARS_HUNDREDS (0xf<<24) /* years hundereds position */ +#define YEARS_MILLENIUMS (0xf<<28) /* years millenium position */ + +/* MASK SHIFT TIME_REG & ALARM_TIME_REG*/ +#define SECOND_SHIFT 0x00 /* seconds units */ +#define MINUTE_SHIFT 0x08 /* minutes units position */ +#define HOUR_SHIFT 0x10 /* hours units position */ +#define MDAY_SHIFT 0x00 /* Month day shift */ +#define MONTH_SHIFT 0x08 /* Month shift */ +#define YEAR_SHIFT 0x10 /* Year shift */ + +#define SECOND_MASK 0x7F +#define MIN_MASK 0x7F +#define HOUR_MASK 0x3F +#define DAY_MASK 0x3F +#define MONTH_MASK 0x7F +#define YEAR_MASK 0xFFFF + +/* date reg equal to time reg, for debug only */ +#define TIME_BYP (1<<9) +#define INT_ENABLE (1<<31) /* interrupt enable */ + +/* STATUS_REG */ +#define CLK_UNCONNECTED (1<<0) +#define PEND_WR_TIME (1<<2) +#define PEND_WR_DATE (1<<3) +#define LOST_WR_TIME (1<<4) +#define LOST_WR_DATE (1<<5) +#define RTC_INT_MASK (1<<31) +#define STATUS_BUSY (PEND_WR_TIME | PEND_WR_DATE) +#define STATUS_FAIL (LOST_WR_TIME | LOST_WR_DATE) + +struct spear_rtc_config { + struct rtc_device *rtc; + struct clk *clk; + spinlock_t lock; + void __iomem *ioaddr; + unsigned int irq_wake; +}; + +static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config) +{ + unsigned int val; + unsigned long flags; + + spin_lock_irqsave(&config->lock, flags); + val = readl(config->ioaddr + STATUS_REG); + val |= RTC_INT_MASK; + writel(val, config->ioaddr + STATUS_REG); + spin_unlock_irqrestore(&config->lock, flags); +} + +static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config) +{ + unsigned int val; + + val = readl(config->ioaddr + CTRL_REG); + if (!(val & INT_ENABLE)) { + spear_rtc_clear_interrupt(config); + val |= INT_ENABLE; + writel(val, config->ioaddr + CTRL_REG); + } +} + +static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config) +{ + unsigned int val; + + val = readl(config->ioaddr + CTRL_REG); + if (val & INT_ENABLE) { + val &= ~INT_ENABLE; + writel(val, config->ioaddr + CTRL_REG); + } +} + +static inline int is_write_complete(struct spear_rtc_config *config) +{ + int ret = 0; + unsigned long flags; + + spin_lock_irqsave(&config->lock, flags); + if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL) + ret = -EIO; + spin_unlock_irqrestore(&config->lock, flags); + + return ret; +} + +static void rtc_wait_not_busy(struct spear_rtc_config *config) +{ + int status, count = 0; + unsigned long flags; + + /* Assuming BUSY may stay active for 80 msec) */ + for (count = 0; count < 80; count++) { + spin_lock_irqsave(&config->lock, flags); + status = readl(config->ioaddr + STATUS_REG); + spin_unlock_irqrestore(&config->lock, flags); + if ((status & STATUS_BUSY) == 0) + break; + /* check status busy, after each msec */ + msleep(1); + } +} + +static irqreturn_t spear_rtc_irq(int irq, void *dev_id) +{ + struct spear_rtc_config *config = dev_id; + unsigned long flags, events = 0; + unsigned int irq_data; + + spin_lock_irqsave(&config->lock, flags); + irq_data = readl(config->ioaddr + STATUS_REG); + spin_unlock_irqrestore(&config->lock, flags); + + if ((irq_data & RTC_INT_MASK)) { + spear_rtc_clear_interrupt(config); + events = RTC_IRQF | RTC_AF; + rtc_update_irq(config->rtc, 1, events); + return IRQ_HANDLED; + } else + return IRQ_NONE; + +} + +static int tm2bcd(struct rtc_time *tm) +{ + if (rtc_valid_tm(tm) != 0) + return -EINVAL; + tm->tm_sec = bin2bcd(tm->tm_sec); + tm->tm_min = bin2bcd(tm->tm_min); + tm->tm_hour = bin2bcd(tm->tm_hour); + tm->tm_mday = bin2bcd(tm->tm_mday); + tm->tm_mon = bin2bcd(tm->tm_mon + 1); + tm->tm_year = bin2bcd(tm->tm_year); + + return 0; +} + +static void bcd2tm(struct rtc_time *tm) +{ + tm->tm_sec = bcd2bin(tm->tm_sec); + tm->tm_min = bcd2bin(tm->tm_min); + tm->tm_hour = bcd2bin(tm->tm_hour); + tm->tm_mday = bcd2bin(tm->tm_mday); + tm->tm_mon = bcd2bin(tm->tm_mon) - 1; + /* epoch == 1900 */ + tm->tm_year = bcd2bin(tm->tm_year); +} + +/* + * spear_rtc_read_time - set the time + * @dev: rtc device in use + * @tm: holds date and time + * + * This function read time and date. On success it will return 0 + * otherwise -ve error is returned. + */ +static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct spear_rtc_config *config = dev_get_drvdata(dev); + unsigned int time, date; + + /* we don't report wday/yday/isdst ... */ + rtc_wait_not_busy(config); + + time = readl(config->ioaddr + TIME_REG); + date = readl(config->ioaddr + DATE_REG); + tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; + tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; + tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; + tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; + tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; + tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; + + bcd2tm(tm); + return 0; +} + +/* + * spear_rtc_set_time - set the time + * @dev: rtc device in use + * @tm: holds date and time + * + * This function set time and date. On success it will return 0 + * otherwise -ve error is returned. + */ +static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct spear_rtc_config *config = dev_get_drvdata(dev); + unsigned int time, date; + + if (tm2bcd(tm) < 0) + return -EINVAL; + + rtc_wait_not_busy(config); + time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) | + (tm->tm_hour << HOUR_SHIFT); + date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) | + (tm->tm_year << YEAR_SHIFT); + writel(time, config->ioaddr + TIME_REG); + writel(date, config->ioaddr + DATE_REG); + + return is_write_complete(config); +} + +/* + * spear_rtc_read_alarm - read the alarm time + * @dev: rtc device in use + * @alm: holds alarm date and time + * + * This function read alarm time and date. On success it will return 0 + * otherwise -ve error is returned. + */ +static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct spear_rtc_config *config = dev_get_drvdata(dev); + unsigned int time, date; + + rtc_wait_not_busy(config); + + time = readl(config->ioaddr + ALARM_TIME_REG); + date = readl(config->ioaddr + ALARM_DATE_REG); + alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; + alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; + alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; + alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; + alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; + alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; + + bcd2tm(&alm->time); + alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE; + + return 0; +} + +/* + * spear_rtc_set_alarm - set the alarm time + * @dev: rtc device in use + * @alm: holds alarm date and time + * + * This function set alarm time and date. On success it will return 0 + * otherwise -ve error is returned. + */ +static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct spear_rtc_config *config = dev_get_drvdata(dev); + unsigned int time, date; + int err; + + if (tm2bcd(&alm->time) < 0) + return -EINVAL; + + rtc_wait_not_busy(config); + + time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min << + MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT); + date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon << + MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT); + + writel(time, config->ioaddr + ALARM_TIME_REG); + writel(date, config->ioaddr + ALARM_DATE_REG); + err = is_write_complete(config); + if (err < 0) + return err; + + if (alm->enabled) + spear_rtc_enable_interrupt(config); + else + spear_rtc_disable_interrupt(config); + + return 0; +} + +static int spear_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct spear_rtc_config *config = dev_get_drvdata(dev); + int ret = 0; + + spear_rtc_clear_interrupt(config); + + switch (enabled) { + case 0: + /* alarm off */ + spear_rtc_disable_interrupt(config); + break; + case 1: + /* alarm on */ + spear_rtc_enable_interrupt(config); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static struct rtc_class_ops spear_rtc_ops = { + .read_time = spear_rtc_read_time, + .set_time = spear_rtc_set_time, + .read_alarm = spear_rtc_read_alarm, + .set_alarm = spear_rtc_set_alarm, + .alarm_irq_enable = spear_alarm_irq_enable, +}; + +static int spear_rtc_probe(struct platform_device *pdev) +{ + struct resource *res; + struct spear_rtc_config *config; + int status = 0; + int irq; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "no resource defined\n"); + return -EBUSY; + } + + config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL); + if (!config) + return -ENOMEM; + + /* alarm irqs */ + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "no update irq?\n"); + return irq; + } + + status = devm_request_irq(&pdev->dev, irq, spear_rtc_irq, 0, pdev->name, + config); + if (status) { + dev_err(&pdev->dev, "Alarm interrupt IRQ%d already claimed\n", + irq); + return status; + } + + config->ioaddr = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(config->ioaddr)) + return PTR_ERR(config->ioaddr); + + config->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(config->clk)) + return PTR_ERR(config->clk); + + status = clk_prepare_enable(config->clk); + if (status < 0) + return status; + + spin_lock_init(&config->lock); + platform_set_drvdata(pdev, config); + + config->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, + &spear_rtc_ops, THIS_MODULE); + if (IS_ERR(config->rtc)) { + dev_err(&pdev->dev, "can't register RTC device, err %ld\n", + PTR_ERR(config->rtc)); + status = PTR_ERR(config->rtc); + goto err_disable_clock; + } + + config->rtc->uie_unsupported = 1; + + if (!device_can_wakeup(&pdev->dev)) + device_init_wakeup(&pdev->dev, 1); + + return 0; + +err_disable_clock: + clk_disable_unprepare(config->clk); + + return status; +} + +static int spear_rtc_remove(struct platform_device *pdev) +{ + struct spear_rtc_config *config = platform_get_drvdata(pdev); + + spear_rtc_disable_interrupt(config); + clk_disable_unprepare(config->clk); + device_init_wakeup(&pdev->dev, 0); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int spear_rtc_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct spear_rtc_config *config = platform_get_drvdata(pdev); + int irq; + + irq = platform_get_irq(pdev, 0); + if (device_may_wakeup(&pdev->dev)) { + if (!enable_irq_wake(irq)) + config->irq_wake = 1; + } else { + spear_rtc_disable_interrupt(config); + clk_disable(config->clk); + } + + return 0; +} + +static int spear_rtc_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct spear_rtc_config *config = platform_get_drvdata(pdev); + int irq; + + irq = platform_get_irq(pdev, 0); + + if (device_may_wakeup(&pdev->dev)) { + if (config->irq_wake) { + disable_irq_wake(irq); + config->irq_wake = 0; + } + } else { + clk_enable(config->clk); + spear_rtc_enable_interrupt(config); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(spear_rtc_pm_ops, spear_rtc_suspend, spear_rtc_resume); + +static void spear_rtc_shutdown(struct platform_device *pdev) +{ + struct spear_rtc_config *config = platform_get_drvdata(pdev); + + spear_rtc_disable_interrupt(config); + clk_disable(config->clk); +} + +#ifdef CONFIG_OF +static const struct of_device_id spear_rtc_id_table[] = { + { .compatible = "st,spear600-rtc" }, + {} +}; +MODULE_DEVICE_TABLE(of, spear_rtc_id_table); +#endif + +static struct platform_driver spear_rtc_driver = { + .probe = spear_rtc_probe, + .remove = spear_rtc_remove, + .shutdown = spear_rtc_shutdown, + .driver = { + .name = "rtc-spear", + .pm = &spear_rtc_pm_ops, + .of_match_table = of_match_ptr(spear_rtc_id_table), + }, +}; + +module_platform_driver(spear_rtc_driver); + +MODULE_ALIAS("platform:rtc-spear"); +MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>"); +MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)"); +MODULE_LICENSE("GPL"); |