diff options
Diffstat (limited to 'drivers/rtc/rtc-stmp3xxx.c')
| -rw-r--r-- | drivers/rtc/rtc-stmp3xxx.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-stmp3xxx.c b/drivers/rtc/rtc-stmp3xxx.c new file mode 100644 index 00000000..10287865 --- /dev/null +++ b/drivers/rtc/rtc-stmp3xxx.c @@ -0,0 +1,284 @@ +/* + * Freescale STMP37XX/STMP378X Real Time Clock driver + * + * Copyright (c) 2007 Sigmatel, Inc. + * Peter Hartley, <peter.hartley@sigmatel.com> + * + * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved. + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. + * Copyright 2011 Wolfram Sang, Pengutronix e.K. + */ + +/* + * 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/kernel.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/interrupt.h> +#include <linux/rtc.h> +#include <linux/slab.h> + +#include <mach/common.h> + +#define STMP3XXX_RTC_CTRL 0x0 +#define STMP3XXX_RTC_CTRL_SET 0x4 +#define STMP3XXX_RTC_CTRL_CLR 0x8 +#define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001 +#define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002 +#define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004 + +#define STMP3XXX_RTC_STAT 0x10 +#define STMP3XXX_RTC_STAT_STALE_SHIFT 16 +#define STMP3XXX_RTC_STAT_RTC_PRESENT 0x80000000 + +#define STMP3XXX_RTC_SECONDS 0x30 + +#define STMP3XXX_RTC_ALARM 0x40 + +#define STMP3XXX_RTC_PERSISTENT0 0x60 +#define STMP3XXX_RTC_PERSISTENT0_SET 0x64 +#define STMP3XXX_RTC_PERSISTENT0_CLR 0x68 +#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN 0x00000002 +#define STMP3XXX_RTC_PERSISTENT0_ALARM_EN 0x00000004 +#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE 0x00000080 + +struct stmp3xxx_rtc_data { + struct rtc_device *rtc; + void __iomem *io; + int irq_alarm; +}; + +static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data) +{ + /* + * 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 (readl(rtc_data->io + STMP3XXX_RTC_STAT) & + (0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)) + cpu_relax(); +} + +/* Time read/write */ +static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) +{ + struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); + + stmp3xxx_wait_time(rtc_data); + rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm); + return 0; +} + +static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t) +{ + struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); + + writel(t, rtc_data->io + STMP3XXX_RTC_SECONDS); + stmp3xxx_wait_time(rtc_data); + return 0; +} + +/* interrupt(s) handler */ +static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id) +{ + struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id); + u32 status = readl(rtc_data->io + STMP3XXX_RTC_CTRL); + + if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) { + writel(STMP3XXX_RTC_CTRL_ALARM_IRQ, + rtc_data->io + STMP3XXX_RTC_CTRL_CLR); + rtc_update_irq(rtc_data->rtc, 1, RTC_AF | RTC_IRQF); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); + + if (enabled) { + writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | + STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN, + rtc_data->io + STMP3XXX_RTC_PERSISTENT0_SET); + writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, + rtc_data->io + STMP3XXX_RTC_CTRL_SET); + } else { + writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | + STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN, + rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR); + writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, + rtc_data->io + STMP3XXX_RTC_CTRL_CLR); + } + return 0; +} + +static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); + + rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time); + return 0; +} + +static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + unsigned long t; + struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); + + rtc_tm_to_time(&alm->time, &t); + writel(t, rtc_data->io + STMP3XXX_RTC_ALARM); + + stmp3xxx_alarm_irq_enable(dev, alm->enabled); + + return 0; +} + +static struct rtc_class_ops stmp3xxx_rtc_ops = { + .alarm_irq_enable = + stmp3xxx_alarm_irq_enable, + .read_time = stmp3xxx_rtc_gettime, + .set_mmss = stmp3xxx_rtc_set_mmss, + .read_alarm = stmp3xxx_rtc_read_alarm, + .set_alarm = stmp3xxx_rtc_set_alarm, +}; + +static int stmp3xxx_rtc_remove(struct platform_device *pdev) +{ + struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev); + + if (!rtc_data) + return 0; + + writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, + rtc_data->io + STMP3XXX_RTC_CTRL_CLR); + free_irq(rtc_data->irq_alarm, &pdev->dev); + rtc_device_unregister(rtc_data->rtc); + platform_set_drvdata(pdev, NULL); + iounmap(rtc_data->io); + kfree(rtc_data); + + return 0; +} + +static int stmp3xxx_rtc_probe(struct platform_device *pdev) +{ + struct stmp3xxx_rtc_data *rtc_data; + struct resource *r; + int err; + + rtc_data = kzalloc(sizeof *rtc_data, GFP_KERNEL); + if (!rtc_data) + return -ENOMEM; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!r) { + dev_err(&pdev->dev, "failed to get resource\n"); + err = -ENXIO; + goto out_free; + } + + rtc_data->io = ioremap(r->start, resource_size(r)); + if (!rtc_data->io) { + dev_err(&pdev->dev, "ioremap failed\n"); + err = -EIO; + goto out_free; + } + + rtc_data->irq_alarm = platform_get_irq(pdev, 0); + + if (!(readl(STMP3XXX_RTC_STAT + rtc_data->io) & + STMP3XXX_RTC_STAT_RTC_PRESENT)) { + dev_err(&pdev->dev, "no device onboard\n"); + err = -ENODEV; + goto out_remap; + } + + platform_set_drvdata(pdev, rtc_data); + + mxs_reset_block(rtc_data->io); + writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | + STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN | + STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE, + rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR); + + writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN | + STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, + rtc_data->io + STMP3XXX_RTC_CTRL_CLR); + + rtc_data->rtc = rtc_device_register(pdev->name, &pdev->dev, + &stmp3xxx_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc_data->rtc)) { + err = PTR_ERR(rtc_data->rtc); + goto out_remap; + } + + err = request_irq(rtc_data->irq_alarm, stmp3xxx_rtc_interrupt, 0, + "RTC alarm", &pdev->dev); + if (err) { + dev_err(&pdev->dev, "Cannot claim IRQ%d\n", + rtc_data->irq_alarm); + goto out_irq_alarm; + } + + return 0; + +out_irq_alarm: + rtc_device_unregister(rtc_data->rtc); +out_remap: + platform_set_drvdata(pdev, NULL); + iounmap(rtc_data->io); +out_free: + kfree(rtc_data); + return err; +} + +#ifdef CONFIG_PM +static int stmp3xxx_rtc_suspend(struct platform_device *dev, pm_message_t state) +{ + return 0; +} + +static int stmp3xxx_rtc_resume(struct platform_device *dev) +{ + struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(dev); + + mxs_reset_block(rtc_data->io); + writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | + STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN | + STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE, + rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR); + return 0; +} +#else +#define stmp3xxx_rtc_suspend NULL +#define stmp3xxx_rtc_resume NULL +#endif + +static struct platform_driver stmp3xxx_rtcdrv = { + .probe = stmp3xxx_rtc_probe, + .remove = stmp3xxx_rtc_remove, + .suspend = stmp3xxx_rtc_suspend, + .resume = stmp3xxx_rtc_resume, + .driver = { + .name = "stmp3xxx-rtc", + .owner = THIS_MODULE, + }, +}; + +module_platform_driver(stmp3xxx_rtcdrv); + +MODULE_DESCRIPTION("STMP3xxx RTC Driver"); +MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com> and " + "Wolfram Sang <w.sang@pengutronix.de>"); +MODULE_LICENSE("GPL"); |