diff options
Diffstat (limited to 'drivers/rtc/rtc-mc13783.c')
| -rw-r--r-- | drivers/rtc/rtc-mc13783.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mc13783.c b/drivers/rtc/rtc-mc13783.c new file mode 100644 index 0000000..850f983 --- /dev/null +++ b/drivers/rtc/rtc-mc13783.c @@ -0,0 +1,262 @@ +/* + * Real Time Clock driver for Freescale MC13783 PMIC + * + * (C) 2009 Sascha Hauer, Pengutronix + * (C) 2009 Uwe Kleine-Koenig, Pengutronix + * + * 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/mfd/mc13783.h> +#include <linux/platform_device.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/rtc.h> + +#define DRIVER_NAME "mc13783-rtc" + +#define MC13783_RTCTOD 20 +#define MC13783_RTCTODA 21 +#define MC13783_RTCDAY 22 +#define MC13783_RTCDAYA 23 + +struct mc13783_rtc { + struct rtc_device *rtc; + struct mc13783 *mc13783; + int valid; +}; + +static int mc13783_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct mc13783_rtc *priv = dev_get_drvdata(dev); + unsigned int seconds, days1, days2; + unsigned long s1970; + int ret; + + mc13783_lock(priv->mc13783); + + if (!priv->valid) { + ret = -ENODATA; + goto out; + } + + ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days1); + if (unlikely(ret)) + goto out; + + ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTOD, &seconds); + if (unlikely(ret)) + goto out; + + ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days2); +out: + mc13783_unlock(priv->mc13783); + + if (ret) + return ret; + + if (days2 == days1 + 1) { + if (seconds >= 86400 / 2) + days2 = days1; + else + days1 = days2; + } + + if (days1 != days2) + return -EIO; + + s1970 = days1 * 86400 + seconds; + + rtc_time_to_tm(s1970, tm); + + return rtc_valid_tm(tm); +} + +static int mc13783_rtc_set_mmss(struct device *dev, unsigned long secs) +{ + struct mc13783_rtc *priv = dev_get_drvdata(dev); + unsigned int seconds, days; + int ret; + + seconds = secs % 86400; + days = secs / 86400; + + mc13783_lock(priv->mc13783); + + /* + * first write seconds=0 to prevent a day switch between writing days + * and seconds below + */ + ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, 0); + if (unlikely(ret)) + goto out; + + ret = mc13783_reg_write(priv->mc13783, MC13783_RTCDAY, days); + if (unlikely(ret)) + goto out; + + ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, seconds); + if (unlikely(ret)) + goto out; + + ret = mc13783_ackirq(priv->mc13783, MC13783_IRQ_RTCRST); + if (unlikely(ret)) + goto out; + + ret = mc13783_unmask(priv->mc13783, MC13783_IRQ_RTCRST); +out: + priv->valid = !ret; + + mc13783_unlock(priv->mc13783); + + return ret; +} + +static irqreturn_t mc13783_rtc_update_handler(int irq, void *dev) +{ + struct mc13783_rtc *priv = dev; + struct mc13783 *mc13783 = priv->mc13783; + + dev_dbg(&priv->rtc->dev, "1HZ\n"); + + rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_UF); + + mc13783_ackirq(mc13783, irq); + + return IRQ_HANDLED; +} + +static int mc13783_rtc_update_irq_enable(struct device *dev, + unsigned int enabled) +{ + struct mc13783_rtc *priv = dev_get_drvdata(dev); + int ret = -ENODATA; + + mc13783_lock(priv->mc13783); + if (!priv->valid) + goto out; + + ret = (enabled ? mc13783_unmask : mc13783_mask)(priv->mc13783, + MC13783_IRQ_1HZ); +out: + mc13783_unlock(priv->mc13783); + + return ret; +} + +static const struct rtc_class_ops mc13783_rtc_ops = { + .read_time = mc13783_rtc_read_time, + .set_mmss = mc13783_rtc_set_mmss, + .update_irq_enable = mc13783_rtc_update_irq_enable, +}; + +static irqreturn_t mc13783_rtc_reset_handler(int irq, void *dev) +{ + struct mc13783_rtc *priv = dev; + struct mc13783 *mc13783 = priv->mc13783; + + dev_dbg(&priv->rtc->dev, "RTCRST\n"); + priv->valid = 0; + + mc13783_mask(mc13783, irq); + + return IRQ_HANDLED; +} + +static int __devinit mc13783_rtc_probe(struct platform_device *pdev) +{ + int ret; + struct mc13783_rtc *priv; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->mc13783 = dev_get_drvdata(pdev->dev.parent); + platform_set_drvdata(pdev, priv); + + priv->valid = 1; + + mc13783_lock(priv->mc13783); + + ret = mc13783_irq_request(priv->mc13783, MC13783_IRQ_RTCRST, + mc13783_rtc_reset_handler, DRIVER_NAME, priv); + if (ret) + goto err_reset_irq_request; + + ret = mc13783_irq_request_nounmask(priv->mc13783, MC13783_IRQ_1HZ, + mc13783_rtc_update_handler, DRIVER_NAME, priv); + if (ret) + goto err_update_irq_request; + + mc13783_unlock(priv->mc13783); + + priv->rtc = rtc_device_register(pdev->name, + &pdev->dev, &mc13783_rtc_ops, THIS_MODULE); + + if (IS_ERR(priv->rtc)) { + ret = PTR_ERR(priv->rtc); + + mc13783_lock(priv->mc13783); + + mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv); +err_update_irq_request: + + mc13783_irq_free(priv->mc13783, MC13783_IRQ_RTCRST, priv); +err_reset_irq_request: + + mc13783_unlock(priv->mc13783); + + platform_set_drvdata(pdev, NULL); + kfree(priv); + } + + return ret; +} + +static int __devexit mc13783_rtc_remove(struct platform_device *pdev) +{ + struct mc13783_rtc *priv = platform_get_drvdata(pdev); + + rtc_device_unregister(priv->rtc); + + mc13783_lock(priv->mc13783); + + mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv); + mc13783_irq_free(priv->mc13783, MC13783_IRQ_RTCRST, priv); + + mc13783_unlock(priv->mc13783); + + platform_set_drvdata(pdev, NULL); + + kfree(priv); + + return 0; +} + +static struct platform_driver mc13783_rtc_driver = { + .remove = __devexit_p(mc13783_rtc_remove), + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + }, +}; + +static int __init mc13783_rtc_init(void) +{ + return platform_driver_probe(&mc13783_rtc_driver, &mc13783_rtc_probe); +} +module_init(mc13783_rtc_init); + +static void __exit mc13783_rtc_exit(void) +{ + platform_driver_unregister(&mc13783_rtc_driver); +} +module_exit(mc13783_rtc_exit); + +MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); +MODULE_DESCRIPTION("RTC driver for Freescale MC13783 PMIC"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRIVER_NAME); |
