diff options
Diffstat (limited to 'drivers/rtc/rtc-spear.c')
| -rw-r--r-- | drivers/rtc/rtc-spear.c | 534 |
1 files changed, 534 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-spear.c b/drivers/rtc/rtc-spear.c new file mode 100644 index 000000000000..893bac2bb21b --- /dev/null +++ b/drivers/rtc/rtc-spear.c @@ -0,0 +1,534 @@ +/* + * drivers/rtc/rtc-spear.c + * + * Copyright (C) 2010 ST Microelectronics + * Rajeev Kumar<[email protected]> + * + * 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/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 clk *clk; + spinlock_t lock; + void __iomem *ioaddr; +}; + +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 rtc_device *rtc = (struct rtc_device *)dev_id; + struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); + 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(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 platform_device *pdev = to_platform_device(dev); + struct rtc_device *rtc = platform_get_drvdata(pdev); + struct spear_rtc_config *config = dev_get_drvdata(&rtc->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 platform_device *pdev = to_platform_device(dev); + struct rtc_device *rtc = platform_get_drvdata(pdev); + struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); + unsigned int time, date, err = 0; + + 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); + err = is_write_complete(config); + if (err < 0) + return err; + + return 0; +} + +/* + * 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 platform_device *pdev = to_platform_device(dev); + struct rtc_device *rtc = platform_get_drvdata(pdev); + struct spear_rtc_config *config = dev_get_drvdata(&rtc->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 platform_device *pdev = to_platform_device(dev); + struct rtc_device *rtc = platform_get_drvdata(pdev); + struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); + unsigned int time, date, err = 0; + + 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 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, +}; + +static int __devinit spear_rtc_probe(struct platform_device *pdev) +{ + struct resource *res; + struct rtc_device *rtc; + struct spear_rtc_config *config; + unsigned 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; + } + if (!request_mem_region(res->start, resource_size(res), pdev->name)) { + dev_err(&pdev->dev, "rtc region already claimed\n"); + return -EBUSY; + } + + config = kzalloc(sizeof(*config), GFP_KERNEL); + if (!config) { + dev_err(&pdev->dev, "out of memory\n"); + status = -ENOMEM; + goto err_release_region; + } + + config->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(config->clk)) { + status = PTR_ERR(config->clk); + goto err_kfree; + } + + status = clk_enable(config->clk); + if (status < 0) + goto err_clk_put; + + config->ioaddr = ioremap(res->start, resource_size(res)); + if (!config->ioaddr) { + dev_err(&pdev->dev, "ioremap fail\n"); + status = -ENOMEM; + goto err_disable_clock; + } + + spin_lock_init(&config->lock); + + rtc = rtc_device_register(pdev->name, &pdev->dev, &spear_rtc_ops, + THIS_MODULE); + if (IS_ERR(rtc)) { + dev_err(&pdev->dev, "can't register RTC device, err %ld\n", + PTR_ERR(rtc)); + status = PTR_ERR(rtc); + goto err_iounmap; + } + + platform_set_drvdata(pdev, rtc); + dev_set_drvdata(&rtc->dev, config); + + /* alarm irqs */ + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "no update irq?\n"); + status = irq; + goto err_clear_platdata; + } + + status = request_irq(irq, spear_rtc_irq, 0, pdev->name, rtc); + if (status) { + dev_err(&pdev->dev, "Alarm interrupt IRQ%d already \ + claimed\n", irq); + goto err_clear_platdata; + } + + if (!device_can_wakeup(&pdev->dev)) + device_init_wakeup(&pdev->dev, 1); + + return 0; + +err_clear_platdata: + platform_set_drvdata(pdev, NULL); + dev_set_drvdata(&rtc->dev, NULL); + rtc_device_unregister(rtc); +err_iounmap: + iounmap(config->ioaddr); +err_disable_clock: + clk_disable(config->clk); +err_clk_put: + clk_put(config->clk); +err_kfree: + kfree(config); +err_release_region: + release_mem_region(res->start, resource_size(res)); + + return status; +} + +static int __devexit spear_rtc_remove(struct platform_device *pdev) +{ + struct rtc_device *rtc = platform_get_drvdata(pdev); + struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); + int irq; + struct resource *res; + + /* leave rtc running, but disable irqs */ + spear_rtc_disable_interrupt(config); + device_init_wakeup(&pdev->dev, 0); + irq = platform_get_irq(pdev, 0); + if (irq) + free_irq(irq, pdev); + clk_disable(config->clk); + clk_put(config->clk); + iounmap(config->ioaddr); + kfree(config); + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res) + release_mem_region(res->start, resource_size(res)); + platform_set_drvdata(pdev, NULL); + dev_set_drvdata(&rtc->dev, NULL); + rtc_device_unregister(rtc); + + return 0; +} + +#ifdef CONFIG_PM + +static int spear_rtc_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct rtc_device *rtc = platform_get_drvdata(pdev); + struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); + int irq; + + irq = platform_get_irq(pdev, 0); + if (device_may_wakeup(&pdev->dev)) + enable_irq_wake(irq); + else { + spear_rtc_disable_interrupt(config); + clk_disable(config->clk); + } + + return 0; +} + +static int spear_rtc_resume(struct platform_device *pdev) +{ + struct rtc_device *rtc = platform_get_drvdata(pdev); + struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); + int irq; + + irq = platform_get_irq(pdev, 0); + + if (device_may_wakeup(&pdev->dev)) + disable_irq_wake(irq); + else { + clk_enable(config->clk); + spear_rtc_enable_interrupt(config); + } + + return 0; +} + +#else +#define spear_rtc_suspend NULL +#define spear_rtc_resume NULL +#endif + +static void spear_rtc_shutdown(struct platform_device *pdev) +{ + struct rtc_device *rtc = platform_get_drvdata(pdev); + struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); + + spear_rtc_disable_interrupt(config); + clk_disable(config->clk); +} + +static struct platform_driver spear_rtc_driver = { + .probe = spear_rtc_probe, + .remove = __devexit_p(spear_rtc_remove), + .suspend = spear_rtc_suspend, + .resume = spear_rtc_resume, + .shutdown = spear_rtc_shutdown, + .driver = { + .name = "rtc-spear", + }, +}; + +static int __init rtc_init(void) +{ + return platform_driver_register(&spear_rtc_driver); +} +module_init(rtc_init); + +static void __exit rtc_exit(void) +{ + platform_driver_unregister(&spear_rtc_driver); +} +module_exit(rtc_exit); + +MODULE_ALIAS("platform:rtc-spear"); +MODULE_AUTHOR("Rajeev Kumar <[email protected]>"); +MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)"); +MODULE_LICENSE("GPL"); |