diff options
Diffstat (limited to 'drivers/rtc/rtc-pl030.c')
| -rw-r--r-- | drivers/rtc/rtc-pl030.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pl030.c b/drivers/rtc/rtc-pl030.c new file mode 100644 index 000000000000..8448eeb9d675 --- /dev/null +++ b/drivers/rtc/rtc-pl030.c @@ -0,0 +1,217 @@ +/* + * linux/drivers/rtc/rtc-pl030.c + * + * Copyright (C) 2000-2001 Deep Blue Solutions Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/module.h> +#include <linux/rtc.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/amba/bus.h> +#include <linux/io.h> + +#define RTC_DR (0) +#define RTC_MR (4) +#define RTC_STAT (8) +#define RTC_EOI (8) +#define RTC_LR (12) +#define RTC_CR (16) +#define RTC_CR_MIE (1 << 0) + +struct pl030_rtc { + struct rtc_device *rtc; + void __iomem *base; +}; + +static irqreturn_t pl030_interrupt(int irq, void *dev_id) +{ + struct pl030_rtc *rtc = dev_id; + writel(0, rtc->base + RTC_EOI); + return IRQ_HANDLED; +} + +static int pl030_open(struct device *dev) +{ + return 0; +} + +static void pl030_release(struct device *dev) +{ +} + +static int pl030_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) +{ + return -ENOIOCTLCMD; +} + +static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct pl030_rtc *rtc = dev_get_drvdata(dev); + + rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time); + return 0; +} + +static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct pl030_rtc *rtc = dev_get_drvdata(dev); + unsigned long time; + int ret; + + /* + * At the moment, we can only deal with non-wildcarded alarm times. + */ + ret = rtc_valid_tm(&alrm->time); + if (ret == 0) + ret = rtc_tm_to_time(&alrm->time, &time); + if (ret == 0) + writel(time, rtc->base + RTC_MR); + return ret; +} + +static int pl030_read_time(struct device *dev, struct rtc_time *tm) +{ + struct pl030_rtc *rtc = dev_get_drvdata(dev); + + rtc_time_to_tm(readl(rtc->base + RTC_DR), tm); + + return 0; +} + +/* + * Set the RTC time. Unfortunately, we can't accurately set + * the point at which the counter updates. + * + * Also, since RTC_LR is transferred to RTC_CR on next rising + * edge of the 1Hz clock, we must write the time one second + * in advance. + */ +static int pl030_set_time(struct device *dev, struct rtc_time *tm) +{ + struct pl030_rtc *rtc = dev_get_drvdata(dev); + unsigned long time; + int ret; + + ret = rtc_tm_to_time(tm, &time); + if (ret == 0) + writel(time + 1, rtc->base + RTC_LR); + + return ret; +} + +static const struct rtc_class_ops pl030_ops = { + .open = pl030_open, + .release = pl030_release, + .ioctl = pl030_ioctl, + .read_time = pl030_read_time, + .set_time = pl030_set_time, + .read_alarm = pl030_read_alarm, + .set_alarm = pl030_set_alarm, +}; + +static int pl030_probe(struct amba_device *dev, void *id) +{ + struct pl030_rtc *rtc; + int ret; + + ret = amba_request_regions(dev, NULL); + if (ret) + goto err_req; + + rtc = kmalloc(sizeof(*rtc), GFP_KERNEL); + if (!rtc) { + ret = -ENOMEM; + goto err_rtc; + } + + rtc->base = ioremap(dev->res.start, SZ_4K); + if (!rtc->base) { + ret = -ENOMEM; + goto err_map; + } + + __raw_writel(0, rtc->base + RTC_CR); + __raw_writel(0, rtc->base + RTC_EOI); + + amba_set_drvdata(dev, rtc); + + ret = request_irq(dev->irq[0], pl030_interrupt, IRQF_DISABLED, + "rtc-pl030", rtc); + if (ret) + goto err_irq; + + rtc->rtc = rtc_device_register("pl030", &dev->dev, &pl030_ops, + THIS_MODULE); + if (IS_ERR(rtc->rtc)) { + ret = PTR_ERR(rtc->rtc); + goto err_reg; + } + + return 0; + + err_reg: + free_irq(dev->irq[0], rtc); + err_irq: + iounmap(rtc->base); + err_map: + kfree(rtc); + err_rtc: + amba_release_regions(dev); + err_req: + return ret; +} + +static int pl030_remove(struct amba_device *dev) +{ + struct pl030_rtc *rtc = amba_get_drvdata(dev); + + amba_set_drvdata(dev, NULL); + + writel(0, rtc->base + RTC_CR); + + free_irq(dev->irq[0], rtc); + rtc_device_unregister(rtc->rtc); + iounmap(rtc->base); + kfree(rtc); + amba_release_regions(dev); + + return 0; +} + +static struct amba_id pl030_ids[] = { + { + .id = 0x00041030, + .mask = 0x000fffff, + }, + { 0, 0 }, +}; + +static struct amba_driver pl030_driver = { + .drv = { + .name = "rtc-pl030", + }, + .probe = pl030_probe, + .remove = pl030_remove, + .id_table = pl030_ids, +}; + +static int __init pl030_init(void) +{ + return amba_driver_register(&pl030_driver); +} + +static void __exit pl030_exit(void) +{ + amba_driver_unregister(&pl030_driver); +} + +module_init(pl030_init); +module_exit(pl030_exit); + +MODULE_AUTHOR("Russell King <[email protected]>"); +MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver"); +MODULE_LICENSE("GPL"); |