diff options
Diffstat (limited to 'drivers/rtc/rtc-mxs.c')
| -rw-r--r-- | drivers/rtc/rtc-mxs.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mxs.c b/drivers/rtc/rtc-mxs.c new file mode 100644 index 000000000000..02fcfccd8e9d --- /dev/null +++ b/drivers/rtc/rtc-mxs.c @@ -0,0 +1,322 @@ +/* + * Freescale STMP37XX/STMP378X Real Time Clock driver + * + * Copyright (c) 2007 Sigmatel, Inc. + * Peter Hartley, <peter.hartley@sigmatel.com> + * + * Copyright 2008-2010 Freescale Semiconductor, Inc. + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/string.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/interrupt.h> +#include <linux/rtc.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/uaccess.h> + +#include <mach/hardware.h> +#include <mach/regs-rtc.h> + +struct mxs_rtc_data { + struct rtc_device *rtc; + unsigned int base; + int irq_alarm; + int irq_sample; + unsigned irq_count; +}; + +/* Time read/write */ +static int mxs_rtc_gettime(struct device *pdev, struct rtc_time *rtc_tm) +{ + struct mxs_rtc_data *rtc_data = dev_get_drvdata(pdev); + + while (__raw_readl(rtc_data->base + HW_RTC_STAT) & + BF_RTC_STAT_STALE_REGS(0x80)) + cpu_relax(); + + rtc_time_to_tm(__raw_readl(rtc_data->base + HW_RTC_SECONDS), rtc_tm); + return 0; +} + +static int mxs_rtc_settime(struct device *pdev, struct rtc_time *rtc_tm) +{ + unsigned long t; + int rc = rtc_tm_to_time(rtc_tm, &t); + struct mxs_rtc_data *rtc_data = dev_get_drvdata(pdev); + + if (rc == 0) { + __raw_writel(t, rtc_data->base + HW_RTC_SECONDS); + + /* The datasheet doesn't say which way round the + * NEW_REGS/STALE_REGS bitfields go. In fact it's 0x1=P0, + * 0x2=P1, .., 0x20=P5, 0x40=ALARM, 0x80=SECONDS, + */ + while (__raw_readl(rtc_data->base + HW_RTC_STAT) & + BF_RTC_STAT_NEW_REGS(0x80)) + cpu_relax(); + } + return rc; +} + +static irqreturn_t mxs_rtc_interrupt(int irq, void *dev_id) +{ + struct mxs_rtc_data *rtc_data = dev_get_drvdata(dev_id); + u32 status; + u32 events = 0; + + status = __raw_readl(rtc_data->base + HW_RTC_CTRL) & + (BM_RTC_CTRL_ALARM_IRQ | BM_RTC_CTRL_ONEMSEC_IRQ); + if (status & BM_RTC_CTRL_ALARM_IRQ) { + __raw_writel(BM_RTC_CTRL_ALARM_IRQ, + rtc_data->base + HW_RTC_CTRL_CLR); + events |= RTC_AF | RTC_IRQF; + } + if (status & BM_RTC_CTRL_ONEMSEC_IRQ) { + __raw_writel(BM_RTC_CTRL_ONEMSEC_IRQ, + rtc_data->base + HW_RTC_CTRL_CLR); + if (++rtc_data->irq_count % 1000 == 0) { + events |= RTC_UF | RTC_IRQF; + rtc_data->irq_count = 0; + } + } + + if (events) + rtc_update_irq(rtc_data->rtc, 1, events); + + return IRQ_HANDLED; +} + +static int mxs_rtc_open(struct device *pdev) +{ + int r; + struct mxs_rtc_data *rtc_data = dev_get_drvdata(pdev); + + r = request_irq(rtc_data->irq_alarm, mxs_rtc_interrupt, + IRQF_DISABLED, "RTC alarm", pdev); + if (r) { + dev_err(pdev, "Cannot claim IRQ%d\n", rtc_data->irq_alarm); + goto fail_1; + } + r = request_irq(rtc_data->irq_sample, mxs_rtc_interrupt, + IRQF_DISABLED, "RTC tick", pdev); + if (r) { + dev_err(pdev, "Cannot claim IRQ%d\n", rtc_data->irq_sample); + goto fail_2; + } + + return 0; +fail_2: + free_irq(rtc_data->irq_alarm, pdev); +fail_1: + return r; +} + +static void mxs_rtc_release(struct device *pdev) +{ + struct mxs_rtc_data *rtc_data = dev_get_drvdata(pdev); + + __raw_writel(BM_RTC_CTRL_ALARM_IRQ_EN | BM_RTC_CTRL_ONEMSEC_IRQ_EN, + rtc_data->base + HW_RTC_CTRL_CLR); + free_irq(rtc_data->irq_alarm, pdev); + free_irq(rtc_data->irq_sample, pdev); +} + +static int mxs_rtc_ioctl(struct device *pdev, unsigned int cmd, + unsigned long arg) +{ + struct mxs_rtc_data *rtc_data = dev_get_drvdata(pdev); + + switch (cmd) { + case RTC_AIE_OFF: + __raw_writel(BM_RTC_PERSISTENT0_ALARM_EN | + BM_RTC_PERSISTENT0_ALARM_WAKE_EN, + rtc_data->base + HW_RTC_PERSISTENT0_CLR); + __raw_writel(BM_RTC_CTRL_ALARM_IRQ_EN, + rtc_data->base + HW_RTC_CTRL_CLR); + break; + case RTC_AIE_ON: + __raw_writel(BM_RTC_PERSISTENT0_ALARM_EN | + BM_RTC_PERSISTENT0_ALARM_WAKE_EN, + rtc_data->base + HW_RTC_PERSISTENT0_SET); + + __raw_writel(BM_RTC_CTRL_ALARM_IRQ_EN, + rtc_data->base + HW_RTC_CTRL_SET); + break; + case RTC_UIE_ON: + rtc_data->irq_count = 0; + __raw_writel(BM_RTC_CTRL_ONEMSEC_IRQ_EN, + rtc_data->base + HW_RTC_CTRL_SET); + break; + case RTC_UIE_OFF: + __raw_writel(BM_RTC_CTRL_ONEMSEC_IRQ_EN, + rtc_data->base + HW_RTC_CTRL_CLR); + break; + default: + return -ENOIOCTLCMD; + } + + return 0; +} +static int mxs_rtc_read_alarm(struct device *pdev, struct rtc_wkalrm *alm) +{ + u32 t; + struct mxs_rtc_data *rtc_data = dev_get_drvdata(pdev); + + t = __raw_readl(rtc_data->base + HW_RTC_ALARM); + rtc_time_to_tm(t, &alm->time); + return 0; +} + +static int mxs_rtc_set_alarm(struct device *pdev, struct rtc_wkalrm *alm) +{ + unsigned long t; + struct mxs_rtc_data *rtc_data = dev_get_drvdata(pdev); + + rtc_tm_to_time(&alm->time, &t); + __raw_writel(t, rtc_data->base + HW_RTC_ALARM); + return 0; +} + +static struct rtc_class_ops mxs_rtc_ops = { + .open = mxs_rtc_open, + .release = mxs_rtc_release, + .ioctl = mxs_rtc_ioctl, + .read_time = mxs_rtc_gettime, + .set_time = mxs_rtc_settime, + .read_alarm = mxs_rtc_read_alarm, + .set_alarm = mxs_rtc_set_alarm, +}; + +static int mxs_rtc_probe(struct platform_device *pdev) +{ + u32 hwversion; + u32 rtc_stat; + struct resource *res; + struct mxs_rtc_data *rtc_data; + + rtc_data = kzalloc(sizeof(*rtc_data), GFP_KERNEL); + + if (!rtc_data) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res == NULL) { + kfree(rtc_data); + return -ENODEV; + } + rtc_data->base = (unsigned int)IO_ADDRESS(res->start); + + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (res == NULL) { + kfree(rtc_data); + return -ENODEV; + } + rtc_data->irq_alarm = res->start; + + res = platform_get_resource(pdev, IORESOURCE_IRQ, 1); + if (res == NULL) { + kfree(rtc_data); + return -ENODEV; + } + rtc_data->irq_sample = res->start; + + __raw_writel(BM_RTC_PERSISTENT0_ALARM_EN | + BM_RTC_PERSISTENT0_ALARM_WAKE_EN | + BM_RTC_PERSISTENT0_ALARM_WAKE, + rtc_data->base + HW_RTC_PERSISTENT0_CLR); + + hwversion = __raw_readl(rtc_data->base + HW_RTC_VERSION); + rtc_stat = __raw_readl(rtc_data->base + HW_RTC_STAT); + printk(KERN_INFO "MXS RTC driver v1.0 hardware v%u.%u.%u\n", + (hwversion >> 24), + (hwversion >> 16) & 0xFF, + hwversion & 0xFFFF); + + rtc_data->rtc = rtc_device_register(pdev->name, &pdev->dev, + &mxs_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc_data->rtc)) { + kfree(rtc_data); + return PTR_ERR(rtc_data->rtc); + } + + platform_set_drvdata(pdev, rtc_data); + + device_init_wakeup(&pdev->dev, 1); + + return 0; +} + +static int mxs_rtc_remove(struct platform_device *dev) +{ + struct mxs_rtc_data *rtc_data = platform_get_drvdata(dev); + + if (rtc_data) { + rtc_device_unregister(rtc_data->rtc); + kfree(rtc_data); + } + + return 0; +} + +#ifdef CONFIG_PM +static int mxs_rtc_suspend(struct platform_device *dev, pm_message_t state) +{ + return 0; +} + +static int mxs_rtc_resume(struct platform_device *dev) +{ + struct mxs_rtc_data *rtc_data = platform_get_drvdata(dev); + + __raw_writel(BM_RTC_PERSISTENT0_ALARM_EN | + BM_RTC_PERSISTENT0_ALARM_WAKE_EN | + BM_RTC_PERSISTENT0_ALARM_WAKE, + rtc_data->base + HW_RTC_PERSISTENT0_CLR); + return 0; +} +#else +#define mxs_rtc_suspend NULL +#define mxs_rtc_resume NULL +#endif + +static struct platform_driver mxs_rtcdrv = { + .probe = mxs_rtc_probe, + .remove = mxs_rtc_remove, + .suspend = mxs_rtc_suspend, + .resume = mxs_rtc_resume, + .driver = { + .name = "mxs-rtc", + .owner = THIS_MODULE, + }, +}; + +static int __init mxs_rtc_init(void) +{ + return platform_driver_register(&mxs_rtcdrv); +} + +static void __exit mxs_rtc_exit(void) +{ + platform_driver_unregister(&mxs_rtcdrv); +} + +module_init(mxs_rtc_init); +module_exit(mxs_rtc_exit); + +MODULE_DESCRIPTION("MXS RTC Driver"); +MODULE_AUTHOR("dmitry pervushin <dimka@embeddedalley.com>"); +MODULE_LICENSE("GPL"); |