2010/10/16 <achew@xxxxxxxxxx>: > From: Andrew Chew <achew@xxxxxxxxxx> > > This is a platform driver that supports the built-in real-time clock on > Tegra SOCs. > > Signed-off-by: Andrew Chew <achew@xxxxxxxxxx> > Acked-by: Alessandro Zummo <a.zummo@xxxxxxxxxxxx> > --- > Applied Wan ZongShun's corrections. Acked-by: Wan ZongShun <mcuos.com@xxxxxxxxx> > Applied Alessandro Zummo's corrections. > > Âdrivers/rtc/Kconfig   |  10 + > Âdrivers/rtc/Makefile  Â|  Â1 + > Âdrivers/rtc/rtc-tegra.c | Â509 +++++++++++++++++++++++++++++++++++++++++++++++ > Â3 files changed, 520 insertions(+), 0 deletions(-) > Âcreate mode 100644 drivers/rtc/rtc-tegra.c > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index 2432541..ca0da79 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -963,4 +963,14 @@ config RTC_DRV_JZ4740 >     ÂThis driver can also be buillt as a module. If so, the module >     Âwill be called rtc-jz4740. > > +config RTC_DRV_TEGRA > +    tristate "NVIDIA Tegra Internal RTC driver" > +    depends on RTC_CLASS && ARCH_TEGRA > +    help > +     If you say yes here you get support for the > +     Tegra 200 series internal RTC module. > + > +     This drive can also be built as a module. If so, the module > +     will be called rtc-tegra. > + > Âendif # RTC_CLASS > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile > index 4ff4b88..a7f3617 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -91,6 +91,7 @@ obj-$(CONFIG_RTC_DRV_STARFIRE)    Â+= rtc-starfire.o > Âobj-$(CONFIG_RTC_DRV_STK17TA8) += rtc-stk17ta8.o > Âobj-$(CONFIG_RTC_DRV_STMP)   += rtc-stmp3xxx.o > Âobj-$(CONFIG_RTC_DRV_SUN4V)  Â+= rtc-sun4v.o > +obj-$(CONFIG_RTC_DRV_TEGRA)  Â+= rtc-tegra.o > Âobj-$(CONFIG_RTC_DRV_TEST)   += rtc-test.o > Âobj-$(CONFIG_RTC_DRV_TWL4030) Â+= rtc-twl.o > Âobj-$(CONFIG_RTC_DRV_TX4939)  += rtc-tx4939.o > diff --git a/drivers/rtc/rtc-tegra.c b/drivers/rtc/rtc-tegra.c > new file mode 100644 > index 0000000..6c4b2ed > --- /dev/null > +++ b/drivers/rtc/rtc-tegra.c > @@ -0,0 +1,509 @@ > +/* > + * An RTC driver for the NVIDIA Tegra 200 series internal RTC. > + * > + * Copyright (c) 2010, NVIDIA Corporation. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. ÂSee the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License along > + * with this program; if not, write to the Free Software Foundation, Inc., > + * 51 Franklin Street, Fifth Floor, Boston, MA Â02110-1301, USA. > + */ > +#include <linux/kernel.h> > +#include <linux/init.h> > +#include <linux/module.h> > +#include <linux/slab.h> > +#include <linux/irq.h> > +#include <linux/io.h> > +#include <linux/delay.h> > +#include <linux/rtc.h> > +#include <linux/platform_device.h> > + > +/* how many attempts to wait in tegra_rtc_wait_while_busy(). */ > +#define RTC_TEGRA_RETRIES 15 > + > +/* STATUS: This bit is set when a write is initiated on the APB side. It is > + * cleared once the write completes in RTC 32KHz clock domain which could be > + * several thousands of APB clocks. This must be IDLE before a write is > + * initiated. Note that this bit is only for writes. > + * 0 = IDLE > + * 1 = BUSY > + */ > +#define RTC_TEGRA_REG_BUSY           0x004 > +#define RTC_TEGRA_REG_SECONDS         Â0x008 > +#define RTC_TEGRA_REG_SHADOW_SECONDS      0x00c > +#define RTC_TEGRA_REG_MILLI_SECONDS      Â0x010 > +#define RTC_TEGRA_REG_SECONDS_ALARM0      0x014 > +#define RTC_TEGRA_REG_SECONDS_ALARM1      0x018 > +#define RTC_TEGRA_REG_MILLI_SECONDS_ALARM0   0x01c > +#define RTC_TEGRA_REG_INTR_MASK            Â0x028 > +/* a write to this register performs a clear. reg=reg&(~x) */ > +#define RTC_TEGRA_REG_INTR_STATUS       Â0x02c > + > +/* bits in INTR_MASK */ > +#define RTC_TEGRA_INTR_MASK_MSEC_CDN_ALARM   (1<<4) > +#define RTC_TEGRA_INTR_MASK_SEC_CDN_ALARM   Â(1<<3) > +#define RTC_TEGRA_INTR_MASK_MSEC_ALARM     (1<<2) > +#define RTC_TEGRA_INTR_MASK_SEC_ALARM1     (1<<1) > +#define RTC_TEGRA_INTR_MASK_SEC_ALARM0     (1<<0) > + > +/* bits in INTR_STATUS */ > +#define RTC_TEGRA_INTR_STATUS_MSEC_CDN_ALARM  (1<<4) > +#define RTC_TEGRA_INTR_STATUS_SEC_CDN_ALARM  Â(1<<3) > +#define RTC_TEGRA_INTR_STATUS_MSEC_ALARM    (1<<2) > +#define RTC_TEGRA_INTR_STATUS_SEC_ALARM1    (1<<1) > +#define RTC_TEGRA_INTR_STATUS_SEC_ALARM0    (1<<0) > + > +struct tegra_rtc_info { > +    struct platform_device Â*pdev; > +    struct rtc_device    *rtc_dev; > +    void __iomem      Â*rtc_base; /* NULL if not initialized. */ > +    int           tegra_rtc_irq; /* alarm and periodic irq */ > +    spinlock_t       Âtegra_rtc_lock; > +}; > + > +/* check is hardware is accessing APB. */ > +static inline u32 tegra_rtc_check_busy(struct tegra_rtc_info *info) > +{ > +    return readl(info->rtc_base + RTC_TEGRA_REG_BUSY); > +} > + > +/* wait for hardware to be ready for writing. > + * do not call this inside the spin lock because it sleeps. > + */ > +static int tegra_rtc_wait_while_busy(struct device *dev) > +{ > +    struct tegra_rtc_info *info = dev_get_drvdata(dev); > + > +    /* TODO: wait for busy then not busy to catch a leading edge. */ > +    int retries = RTC_TEGRA_RETRIES; > + > +    while (tegra_rtc_check_busy(info)) { > +        if (!retries--) { > +            dev_err(dev, "write failed:retry count exceeded.\n"); > +            return -ETIMEDOUT; > +        } > +        msleep(1); > +    } > + > +    return 0; > +} > + > +/* waits for the RTC to not be busy accessing APB, then write a single value. */ > +static int tegra_rtc_write_not_busy(struct device *dev, unsigned ofs, u32 value) > +{ > +    struct tegra_rtc_info *info = dev_get_drvdata(dev); > +    unsigned long sl_irq_flags; > +    int ret; > + > +    spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags); > + > +    if (tegra_rtc_check_busy(info)) { > +        spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags); > +        ret = tegra_rtc_wait_while_busy(dev); > +        if (ret) > +            return ret; > +        spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags); > +    } > + > +    writel(value, info->rtc_base + ofs); > + > +    spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags); > + > +    return 0; > +} > + > + > +static int tegra_rtc_read_time(struct device *dev, struct rtc_time *tm) > +{ > +    struct tegra_rtc_info *info = dev_get_drvdata(dev); > +    unsigned long sec, msec; > +    unsigned long sl_irq_flags; > + > +    spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags); > + > +    msec = readl(info->rtc_base + RTC_TEGRA_REG_MILLI_SECONDS); > +    sec = readl(info->rtc_base + RTC_TEGRA_REG_SHADOW_SECONDS); > + > +    spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags); > + > +    rtc_time_to_tm(sec, tm); > + > +    dev_vdbg(dev, "time read as %lu. %d/%d/%d %d:%02u:%02u\n", > +        sec, > +        tm->tm_mon + 1, > +        tm->tm_mday, > +        tm->tm_year + 1900, > +        tm->tm_hour, > +        tm->tm_min, > +        tm->tm_sec > +    ); > + > +    return 0; > +} > + > +static int tegra_rtc_set_time(struct device *dev, struct rtc_time *tm) > +{ > +    struct tegra_rtc_info *info = dev_get_drvdata(dev); > +    unsigned long sec; > +    int ret; > + > +    /* convert tm to seconds. */ > +    ret = rtc_valid_tm(tm); > +    if (ret < 0) > +        return ret; > + > +    rtc_tm_to_time(tm, &sec); > + > +    dev_vdbg(dev, "time set to %lu. %d/%d/%d %d:%02u:%02u\n", > +        sec, > +        tm->tm_mon+1, > +        tm->tm_mday, > +        tm->tm_year+1900, > +        tm->tm_hour, > +        tm->tm_min, > +        tm->tm_sec > +    ); > + > +    /* seconds only written if wait succeeded. */ > +    ret = tegra_rtc_write_not_busy(dev, RTC_TEGRA_REG_SECONDS, sec); > + > +    dev_vdbg(dev, "time read back as %d\n", > +        readl(info->rtc_base + RTC_TEGRA_REG_SECONDS)); > + > +    return ret; > +} > + > +static int tegra_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) > +{ > +    struct tegra_rtc_info *info = dev_get_drvdata(dev); > +    unsigned long sec; > +    unsigned long sl_irq_flags; > +    unsigned tmp; > + > +    spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags); > + > +    sec = readl(info->rtc_base + RTC_TEGRA_REG_SECONDS_ALARM0); > + > +    spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags); > + > +    if (sec == 0) { > +        /* alarm is disabled. */ > +        alarm->enabled = 0; > +        alarm->time.tm_mon = -1; > +        alarm->time.tm_mday = -1; > +        alarm->time.tm_year = -1; > +        alarm->time.tm_hour = -1; > +        alarm->time.tm_min = -1; > +        alarm->time.tm_sec = -1; > +    } else { > +        /* alarm is enabled. */ > +        alarm->enabled = 1; > +        rtc_time_to_tm(sec, &alarm->time); > +    } > + > +    tmp = readl(info->rtc_base + RTC_TEGRA_REG_INTR_STATUS); > +    alarm->pending = (tmp & RTC_TEGRA_INTR_STATUS_SEC_ALARM0) != 0; > + > +    return 0; > +} > + > +static int tegra_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) > +{ > +    struct tegra_rtc_info *info = dev_get_drvdata(dev); > +    unsigned status; > +    unsigned long sl_irq_flags; > +    int ret; > + > +    spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags); > + > +    if (tegra_rtc_check_busy(info)) { /* wait for the busy bit to clear. */ > +        spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags); > +        ret = tegra_rtc_wait_while_busy(dev); > +        if (ret) > +            return ret; > +        spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags); > +    } > + > +    /* read the original value, and OR in the flag. */ > +    status = readl(info->rtc_base + RTC_TEGRA_REG_INTR_MASK); > +    if (enabled) > +        status |= RTC_TEGRA_INTR_MASK_SEC_ALARM0; /* set it */ > +    else > +        status &= ~RTC_TEGRA_INTR_MASK_SEC_ALARM0; /* clear it */ > + > +    writel(status, info->rtc_base + RTC_TEGRA_REG_INTR_MASK); > + > +    spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags); > + > +    return 0; > +} > + > +static int tegra_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) > +{ > +    struct tegra_rtc_info *info = dev_get_drvdata(dev); > +    int ret; > +    unsigned long sec; > + > +    if (alarm->enabled) > +        rtc_tm_to_time(&alarm->time, &sec); > +    else > +        sec = 0; > + > +    ret = tegra_rtc_write_not_busy(dev, RTC_TEGRA_REG_SECONDS_ALARM0, sec); > +    dev_vdbg(dev, "alarm read back as %d\n", > +        readl(info->rtc_base + RTC_TEGRA_REG_SECONDS_ALARM0)); > + > +    /* if successfully written and alarm is enabled ... */ > +    if ((ret == 0) && sec) { > +        tegra_rtc_alarm_irq_enable(dev, 1); > + > +        dev_vdbg(dev, "alarm set as %lu. %d/%d/%d %d:%02u:%02u\n", > +            sec, > +            alarm->time.tm_mon+1, > +            alarm->time.tm_mday, > +            alarm->time.tm_year+1900, > +            alarm->time.tm_hour, > +            alarm->time.tm_min, > +            alarm->time.tm_sec); > +    } else { > +        /* disable alarm if 0 or write error. */ > +        dev_vdbg(dev, "alarm disabled\n"); > +        tegra_rtc_alarm_irq_enable(dev, 0); > +    } > + > +    return ret; > +} > + > +/* additional proc lines. */ > +static int tegra_rtc_proc(struct device *dev, struct seq_file *seq) > +{ > +    if (!dev || !dev->driver) > +        return 0; > + > +    return seq_printf(seq, "name\t\t: %s\n", dev_name(dev)); > +} > + > +static irqreturn_t tegra_rtc_irq_handler(int irq, void *data) > +{ > +    struct device *dev = data; > +    struct tegra_rtc_info *info = dev_get_drvdata(dev); > +    unsigned long events = 0; > +    unsigned status; > +    unsigned long sl_irq_flags; > + > +    status = readl(info->rtc_base + RTC_TEGRA_REG_INTR_STATUS); > +    if (status) { > +        /* clear the interrupt masks and status on any irq. */ > +        spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags); > +        writel(0, info->rtc_base + RTC_TEGRA_REG_INTR_MASK); > +        writel(0xffffffff, info->rtc_base + RTC_TEGRA_REG_INTR_STATUS); > +        spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags); > +    } > + > +    /* check if Alarm */ > +    if ((status & RTC_TEGRA_INTR_STATUS_SEC_ALARM0)) > +        events |= RTC_IRQF | RTC_AF; > + > +    /* check if Periodic */ > +    if ((status & RTC_TEGRA_INTR_STATUS_SEC_CDN_ALARM)) > +        events |= RTC_IRQF | RTC_PF; > + > +    rtc_update_irq(info->rtc_dev, 1, events); > + > +    return IRQ_HANDLED; > +} > + > +static struct rtc_class_ops tegra_rtc_ops = { > +    .read_time   Â= tegra_rtc_read_time, > +    .set_time    = tegra_rtc_set_time, > +    .read_alarm   = tegra_rtc_read_alarm, > +    .set_alarm   Â= tegra_rtc_set_alarm, > +    .proc      = tegra_rtc_proc, > +    .alarm_irq_enable = tegra_rtc_alarm_irq_enable, > +}; > + > +static int __devinit tegra_rtc_probe(struct platform_device *pdev) > +{ > +    struct tegra_rtc_info *info; > +    struct resource *res; > +    int ret; > + > +    info = kzalloc(sizeof(struct tegra_rtc_info), GFP_KERNEL); > +    if (!info) > +        return -ENOMEM; > + > +    res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > +    if (!res) { > +        dev_err(&pdev->dev, > +            "Unable to allocate resources for device.\n"); > +        ret = -EBUSY; > +        goto err_free_info; > +    } > + > +    info->tegra_rtc_irq = platform_get_irq(pdev, 0); > +    if (info->tegra_rtc_irq <= 0) { > +        ret = -EBUSY; > +        goto err_free_info; > +    } > + > +    info->rtc_base = ioremap(res->start, resource_size(res)); > +    if (!info->rtc_base) { > +        dev_err(&pdev->dev, "Unable to grab IOs for device.\n"); > +        ret = -EBUSY; > +        goto err_free_info; > +    } > + > +    /* set context info. */ > +    info->pdev = pdev; > +    info->tegra_rtc_lock = __SPIN_LOCK_UNLOCKED(info->tegra_rtc_lock); > + > +    platform_set_drvdata(pdev, info); > + > +    /* clear out the hardware. */ > +    tegra_rtc_write_not_busy(&pdev->dev, RTC_TEGRA_REG_SECONDS_ALARM0, 0); > +    tegra_rtc_write_not_busy(&pdev->dev, RTC_TEGRA_REG_INTR_STATUS, > +                Â0xffffffff); > +    tegra_rtc_write_not_busy(&pdev->dev, RTC_TEGRA_REG_INTR_MASK, 0); > + > +    device_init_wakeup(&pdev->dev, 1); > + > +    info->rtc_dev = rtc_device_register( > +        pdev->name, &pdev->dev, &tegra_rtc_ops, THIS_MODULE); > +    if (IS_ERR(info->rtc_dev)) { > +        ret = PTR_ERR(info->rtc_dev); > +        info->rtc_dev = NULL; > +        dev_err(&pdev->dev, > +            "Unable to register device (err=%d).\n", > +            ret); > +        goto err_iounmap; > +    } > + > +    ret = request_irq(info->tegra_rtc_irq, tegra_rtc_irq_handler, > +        IRQF_TRIGGER_HIGH, "rtc alarm", &pdev->dev); > +    if (ret) { > +        dev_err(&pdev->dev, > +            "Unable to request interrupt for device (err=%d).\n", > +            ret); > +        goto err_dev_unreg; > +    } > + > +    dev_notice(&pdev->dev, "Tegra internal Real Time Clock\n"); > + > +    return 0; > + > +err_dev_unreg: > +    rtc_device_unregister(info->rtc_dev); > +err_iounmap: > +    iounmap(info->rtc_base); > +err_free_info: > +    kfree(info); > + > +    return ret; > +} > + > +static int __devexit tegra_rtc_remove(struct platform_device *pdev) > +{ > +    struct tegra_rtc_info *info = platform_get_drvdata(pdev); > + > +    free_irq(info->tegra_rtc_irq, &pdev->dev); > +    rtc_device_unregister(info->rtc_dev); > +    iounmap(info->rtc_base); > +    kfree(info); > + > +    platform_set_drvdata(pdev, NULL); > + > +    return 0; > +} > + > +#ifdef CONFIG_PM > +static int tegra_rtc_suspend(struct platform_device *pdev, pm_message_t state) > +{ > +    struct device *dev = &pdev->dev; > +    struct tegra_rtc_info *info = platform_get_drvdata(pdev); > + > +    /* only use ALARM0 as a wake source. */ > +    writel(0xffffffff, info->rtc_base + RTC_TEGRA_REG_INTR_STATUS); > +    writel(RTC_TEGRA_INTR_STATUS_SEC_ALARM0, > +        info->rtc_base + RTC_TEGRA_REG_INTR_MASK); > + > +    dev_vdbg(dev, "alarm sec = %d\n", > +        readl(info->rtc_base + RTC_TEGRA_REG_SECONDS_ALARM0)); > + > +    dev_vdbg(dev, "Suspend (device_may_wakeup=%d) irq:%d\n", > +        device_may_wakeup(dev), info->tegra_rtc_irq); > + > +    /* leave the alarms on as a wake source. */ > +    if (device_may_wakeup(dev)) > +        enable_irq_wake(info->tegra_rtc_irq); > + > +    return 0; > +} > + > +static int tegra_rtc_resume(struct platform_device *pdev) > +{ > +    struct device *dev = &pdev->dev; > +    struct tegra_rtc_info *info = platform_get_drvdata(pdev); > +    unsigned int intr_status; > + > +    /* clear */ > +    intr_status = readl(info->rtc_base + RTC_TEGRA_REG_INTR_STATUS); > +    if (intr_status & RTC_TEGRA_INTR_STATUS_SEC_ALARM0) { > +        tegra_rtc_write_not_busy(dev, RTC_TEGRA_REG_INTR_MASK, 0); > +        tegra_rtc_write_not_busy(dev, RTC_TEGRA_REG_INTR_STATUS, > +                    Â0xffffffff); > +    } > + > +    dev_vdbg(dev, "Resume (device_may_wakeup=%d)\n", > +        device_may_wakeup(dev)); > +    /* alarms were left on as a wake source, turn them off. */ > +    if (device_may_wakeup(dev)) > +        disable_irq_wake(info->tegra_rtc_irq); > + > +    return 0; > +} > +#endif > + > +static void tegra_rtc_shutdown(struct platform_device *pdev) > +{ > +    dev_vdbg(&pdev->dev, "disabling interrupts.\n"); > +    tegra_rtc_alarm_irq_enable(&pdev->dev, 0); > +} > + > +MODULE_ALIAS("platform:tegra_rtc"); > +static struct platform_driver tegra_rtc_driver = { > +    .remove     = __devexit_p(tegra_rtc_remove), > +    .shutdown    = tegra_rtc_shutdown, > +    .driver     = { > +        .name  = "tegra_rtc", > +        .owner Â= THIS_MODULE, > +    }, > +#ifdef CONFIG_PM > +    .suspend    Â= tegra_rtc_suspend, > +    .resume     = tegra_rtc_resume, > +#endif > +}; > + > +static int __init tegra_rtc_init(void) > +{ > +    return platform_driver_probe(&tegra_rtc_driver, tegra_rtc_probe); > +} > +module_init(tegra_rtc_init); > + > +static void __exit tegra_rtc_exit(void) > +{ > +    platform_driver_unregister(&tegra_rtc_driver); > +} > +module_exit(tegra_rtc_exit); > + > +MODULE_AUTHOR("Jon Mayo <jmayo@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("driver for Tegra internal RTC"); > +MODULE_LICENSE("GPL"); > -- > 1.7.0.4 > > -- > You received this message because you are subscribed to "rtc-linux". > Membership options at http://groups.google.com/group/rtc-linux . > Please read http://groups.google.com/group/rtc-linux/web/checklist > before submitting a driver. -- *linux-arm-kernel mailing list mail addr:linux-arm-kernel@xxxxxxxxxxxxxxxxxxx you can subscribe by: http://lists.infradead.org/mailman/listinfo/linux-arm-kernel * linux-arm-NUC900 mailing list mail addr:NUC900@xxxxxxxxxxxxxxxx main web: https://groups.google.com/group/NUC900 you can subscribe it by sending me mail: mcuos.com@xxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html